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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.

    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

  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.

    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

  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. Mixer nozzle-externally blown flap noise tests

    NASA Technical Reports Server (NTRS)

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

    1972-01-01

    A summary is given of the noise suppression tests conducted for the STOL aircraft. The tests were made using a large scale mixer nozzle and externally blown flap model. Data were obtained over a range of nozzle exhaust velocities (172 to 284 m/sec) and flap angles. Comparisons were made between the results of the mixer nozzle and those obtained with a standard single convergent nozzle. The resulting conclusions show that a reduction in noise level did occur using the mixer nozzle system.

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

    SciTech Connect

    Symons, G.A.; Staehr, T.W., Westinghouse Hanford

    1996-06-01

    Westinghouse Hanford Company has undertaken the task to develop and demonstrate a method of retrieval for double-shell tank (DST)waste. Mixer pumps were chosen as the planned method of retrieval for the DSTs, based on engineering technology studies,past experience with hydraulic sluicing at the Hanford Site, and experience with mixer pumps at the Westinghouse Savannah River Site. This document outlines a test plan to demonstrate the ability of two 300 hp mixer pumps installed in the AZ-101 tank to mobilize waste.

  7. 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.

  8. 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.

  9. Qualification test of the Ross Double Planetary Mixer

    NASA Astrophysics Data System (ADS)

    Lueders, Kurt F.

    1993-07-01

    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.

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

    NASA Technical Reports Server (NTRS)

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

    1973-01-01

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

  11. 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

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

    EPA Science Inventory

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

  13. 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...

  14. 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...

  15. Influence of using a roller mixer on rejected samples in coagulation tests.

    PubMed

    Aral, Hale; Usta, Murat

    2011-12-01

    The influence of using a roller mixer just after blood collection on the ratio of rejected samples in coagulation tests was investigated retrospectively. Numbers of blood samples collected in centralized units of outpatient clinics for prothrombin time (PT) were 24,050 in group I and 24,500 in group II (H. Aral, unpublished data). In group I, the tubes were inverted manually. In group II, the tubes were left standing on roller mixer with 30 rpm. The ratios of rejected samples of the two groups were compared statistically with ki-square analysis. Using a roller mixer, rate of rejection decreased from 0.79% (group I) to 0.20% (group II) (P<0.001). We suggested using roller mixer to improve the reliability of coagulation testing. Such standardization in preanalytical phase may be helpful in preventing laboratory errors and obtaining correct test results in coagulation tests. © 2011 Blackwell Publishing Ltd.

  16. 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.

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

    SciTech Connect

    TEMPLETON, A.M.

    2000-01-31

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

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

    SciTech Connect

    TEMPLETON, A.M.

    2000-03-06

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

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

    SciTech Connect

    TEMPLETON, A.M.

    2000-04-10

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

  20. 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.

  1. Acceptance test report for the 241-AN-107 caustic addition mixer pump data logger

    SciTech Connect

    Dowell, J.L.

    1996-04-05

    The Acceptance Test Procedure for the 241-AN-107 Caustic Addition Mixer Pump Data logger, WHC-SD-WM-ATP-149, was started on September 25, 1995, and completed November 13, 1995. K.G. Carothers of Tank Waste Remediation Engineering requested the test procedure and ICF Kaiser Control Systems Engineering group wrote the test procedure and executed it at the 305 building in 300 area and at the 241-AN Tank Farm in 200 East area. The purpose of this report is to document that the Caustic addition Mixer Pump Data logger, functioned as intended as installed at 241-AN-107 tank farm.

  2. 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.

  3. 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.

  4. 241-AZ-101 Mixer Pump Demonstration Test Gamma Cart Acceptance Test Procedure and Quality Test Plan (ATP and QTP)

    SciTech Connect

    WHITE, D.A.

    2000-03-01

    Shop Test of the Gamma Cart System to be used in the AZ-101 Mixer Pump Demonstration Test. Tests hardware and software. This procedure involves testing the Instrumentation involved with the Gamma Cart System, local and remote, including: depth indicators, speed controls, interface to data acquisition software and the raising and lowering functions. This Procedure will be performed twice, once for each Gamma Cart System. This procedure does not test the accuracy of the data acquisition software.

  5. 241-AZ-101 Mixer Pump Demonstration Test Gamma Cart Acceptance Test Procedure and Quality Test Plan (ATP and QTP)

    SciTech Connect

    WHITE, D.A.

    2000-01-27

    Shop test of the sludge mobilization cart system to be used in the AZ-101 Mixer Pump Demonstration Test Tests hardware and software. This procedure involves testing the Instrumentation involved with the Gamma Cart System, local and remote, including depth indicators, speed controls, interface to data acquisition software and the raising and lowering functions. This Procedure will be performed twice, once for each Gamma Cart System. This procedure does not test the accuracy of the data acquisition software.

  6. 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

  7. 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.).

  8. 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.

  9. 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.

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

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

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

  11. 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.

  12. 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.

  13. Energy Efficient Engine Exhaust Mixer Model Technology

    NASA Technical Reports Server (NTRS)

    Kozlowski, H.; Larkin, M.

    1981-01-01

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

  14. NON-NEWTONIAN FLUID CAVERN AND NEWTONIAN CLOUD HEIGHT TESTS TO CHARACTERIZE PULSE JET MIXER OPERATION

    SciTech Connect

    Enderlin, Carl W.; Bontha, Jagannadha R.; Bamberger, Judith A.; Nigl, Franz

    2011-01-01

    Pulse jet mixing systems are being developed for use in the Waste Treatment Plant in Washington State. To assist with system development, scaled tests were conducted to obtain experimental measurements of the cloud height for Newtonian slurries and cavern heights for a Non-Newtonian yield stress material. The measurements were required to assess the effective mixing and material mobilization produced during pulse jet mixer operation. The cloud height measurements were obtained for a single steady-state jet directed downward in a spherical-bottom tank. The cloud tests used glass beads in water to evaluate the height of the suspended slurry as a function of jet velocity. Cloud testing revealed that the glass bead material was suspended in the tank quickly and developed a distinctive height for each combination of flow rate and particulate size tested. The solids loading had minimal impact on the cloud height for a given particle size. During all cloud tests, the surface of the tank remained relatively calm, indicating that the slurry was dissipating the mixing energy of the relatively high velocity jet. Cavern tests were conducted to obtain experimental data of non-Newtonian fluid mixing for fluid properties similar to those of certain tank wastes. A transparent material that exhibited a yield stress and shear thinning behavior was used to obtain measurements of steady-state cavern heights as a function of jet velocity. For the non-Newtonian fluid cavern tests, distinct cavern volumes were readily developed for the four velocities tested. A linear relationship was observed to exist between cavern height and nozzle velocity. Since the experimental work detailed in this paper was completed, additional scaled tests have been conducted with pneumatic drive systems and direct drive systems similar to that described for this effort. Data from both types of measurements are shown to be linear; however, effects from the reciprocating drive systems that are not yet

  15. 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…

  16. 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…

  17. 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.

  18. 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

  19. 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.

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

    USDA-ARS?s Scientific Manuscript database

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

  1. 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.

  2. 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

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. Theoretical SIS Mixer Research

    DTIC Science & Technology

    1993-06-01

    experimental results reported for the rf- series dc-parallel biased array SIS mixer. 14. SUBJECT TERMS NIIF •n’n or r nine superconductivity; SIS mixer...on the superlative experimental results reported for the if- series dc-parallel biased array SIS mixer. Th15 doc•ument has been approved fox public...towards realization of ultra-low-noise SIS detectors. D. Rf- series dc-parallel biased arrays for SIS mixing For the Josephson junction oscillator it is

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Optimization of SIS mixer elements

    NASA Technical Reports Server (NTRS)

    Mattauch, Robert J.

    1985-01-01

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

  14. 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.

  15. 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.

  16. Planar doped barrier subharmonic mixers

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  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. Piezoelectric rotational mixer based on a first bending vibration mode.

    PubMed

    Mashimo, Tomoaki

    2013-10-01

    We propose a miniature piezoelectric mixer that can rotate a liquid inside a hole of several millimeters diameter. The mixer has dimensions 14 × 14 × 10 mm with a through-hole (7 mm), and piezoelectric elements bonded to its four identical sides. When the first bending vibration mode of the mixer is excited by ac voltages, rotational flow of liquid is generated by the rotation of an acoustic field (acoustic streaming) in the through-hole. This technology is useful in automating mixing processes such as the mixing by hand of a few drops of blood in medical testing. In this paper, we verify the driving principle experimentally and examine the characteristics of a prototype mixer, including the induced flow velocity, under changes of the amplitude and frequency of the applied voltages. A plastic test tube, used to prevent contamination, is inserted to the through-hole, and the liquid inside the tube is mixed by rotation of the acoustic field.

  20. 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.

  1. 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

  2. Mixer nozzle aeroacoustic characteristics for the energy efficient engine

    NASA Technical Reports Server (NTRS)

    Gliebe, P. R.; Sandusky, G. T.; Chamberlin, R.

    1981-01-01

    Aeroacoustic tests are conducted on scale model mixer nozzle configurations, a separate flow nozzle, and a baseline conical nozzle in an anechoic chamber free-jet facility to investigate exhaust system designs. Far-field acoustic data and exhaust jet plume aerodynamic data are obtained for various combinations of exhaust jet velocity and simulated flight speed, with corrected microphone data at a constant 12.2 m arc distance, and scaled acoustic data at a sideline distance of 457 m. It is found that jet plume aerodynamic and acoustic characteristics of lobed mixer exhaust systems are similar to those of a conical nozzle operating at the same specific thrust, although differences occur at high frequencies, where the sound pressure level of the mixer nozzle is 1-5 dB higher than that of a conical nozzle. In addition, no direct correlation is found between exit plane turbulence levels and plume development or acoustic characteristics for mixer exhaust configurations.

  3. Ultrafast microfluidic mixer and freeze-quenching device.

    PubMed

    Lin, Yu; Gerfen, Gary J; Rousseau, Denis L; Yeh, Syun-Ru

    2003-10-15

    The freeze-quenching technique is extremely useful for trapping meta-stable intermediates populated during fast chemical or biochemical reactions. The application of this technique, however, is limited by the long mixing time of conventional solution mixers and the slow freezing time of cryogenic fluids. To overcome these problems, we have designed and tested a novel microfluidic silicon mixer equipped with a new freeze-quenching device, with which reactions can be followed down to 50 micros. In the microfluidic silicon mixer, seven 10-microm-diameter vertical pillars are arranged perpendicular to the flow direction and in a staggered fashion in the 450-pL mixing chamber to enhance turbulent mixing. The mixed-solution jet, with a cross section of 10 microm x 100 microm, exits from the microfluidic silicon mixer with a linear flow velocity of 20 m/s. It instantaneously freezes on one of two rotating copper wheels maintained at 77 K and is subsequently ground into an ultrafine powder. The ultrafine frozen powder exhibits excellent spectral quality and high packing factor and can be readily transferred between spectroscopic observation cells. The microfluidic mixer was tested by the reaction between azide and myoglobin at pH 5.0. It was found that complete mixing was achieved within the mixing dead time of the mixer (20 micros), and the first observable point for this coupled device was determined to be 50 micros, which is approximately 2 orders of magnitude faster than commercially available instruments.

  4. 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.

  5. 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.

  6. 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.

  7. Forced mixer lobes in ejector designs

    NASA Technical Reports Server (NTRS)

    Presz, W. M., Jr.; Morin, B. L.; Gousy, R. G.

    1986-01-01

    Forced mixer lobes in augmentor primary ejectors obtain a 100-percent increase in pumping over conventional design, together with nearly complete mixing in very short mixing ducts, through the generation of large scale axial vorticity in the mixing duct. The vorticity causes rapid mixing of the primary and secondary flows with low losses; since mixing length is minimized, wall friction losses are reduced, allowing more secondary flow to be pumped for a given total pressure in the primary flow. Analytical results are presented that are judged to have significant implications for future ejector test work.

  8. 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.

  9. 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.

  10. 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.

  11. Superconducting Mixers for Far-Infrared Spectroscopy

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

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

  12. A novel micro-mixer with a quasi-active rotor: fabrication and design improvement

    NASA Astrophysics Data System (ADS)

    Kim, Yongdae; Lee, Jongkwang; Kwon, Sejin

    2009-10-01

    In the present paper, a novel micro-mixer with a quasi-active rotor for micro-plant applications is proposed and design considerations for the improvement of the mixing performance of the proposed micro-mixer are derived. The proposed micro-rotor mixer combines an active micro-mixer with a passive micro-mixer. The micro-rotor, which is a moving part of an active micro-mixer, is added to the micro-chamber of a passive micro-mixer. The micro-rotor was rotated by inflows tangential to the chamber, causing strong perturbations. Two models of the micro-rotor mixer were fabricated with six layers of photosensitive glass which were individually fabricated and thermally bonded together. Improvement in the design of the micro-rotor mixer was achieved after the fabrication and experimental testing of the first model. In the design of the second model, the channel width and the rotor diameter were diminished and the number of rotor blades was increased from four to five. Through these design improvements, the micro-rotor started rotating at a lower Reynolds number; the rotor rotated at Re 1000 in the first model, whereas it did so at Re 200 in the second model. The mixing efficiency values of the micro-mixers were measured using an image analysis method. In the results, the mixing performance was dominated by molecular diffusion in the low Reynolds number region. On the other hand, convection flows such as twisted flows and Coanda flows dominated the mixing performance in the higher Reynolds number region. In the upper Reynolds number region, the micro-rotor was rotated and strong perturbations were induced. The mixing efficiency values of the micro-rotor mixers were found to exceed 90% when the rotor was rotated.

  13. 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.

  14. 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.

  15. 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).

  16. 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.

  17. Processing highly filled polyvinyl chloride in double-screw mixers

    SciTech Connect

    Laukhin, V.Y.

    1983-07-01

    As there is a limit on the effect that plasticization can have on viscosity and because of the rate of destruction of the polymeric system the manufacture of highly filled PV compositions with optimum conditions of low shear stress, freedom from attack by oxygen on the polymer composition, and a continuous technological process is proposed to guarantee constant quality in the properties of tile and linoleum. Screw type mixers must be replaced by continuous type SN double-screw mixers. Several screw designs are tested and samples subjected to differential thermal analysis and thermogravimetric analysis. The rheological properties of pastes obtained from tile and linoleum specimens were tested to obtain comparative data on the structural formation processes. The tests indicate that polyvinyl chloride processed in a double screw machine has a higher molecular weight and a more highly branched molecule than the same composition processed in a rotary mixer. A study of PVC mixtures indicate that it is suitable to plasticize highly filled PVC compositions in a double screw type SN mixer.

  18. 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.

  19. 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

  20. 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.

  1. Jet mixer noise suppressor using acoustic feedback

    NASA Technical Reports Server (NTRS)

    Rice, Edward J. (Inventor)

    1994-01-01

    The present invention generally relates to providing an improved jet mixer noise suppressor for high speed jets that rapidly mixes high speed air flow with a lower speed air flow, and more particularly, relates to an improved jet mixer noise suppressor that uses feedback of acoustic waves produced by the interaction of sheer flow instability waves with an obstacle downstream of the jet nozzle.

  2. Jet mixer noise suppressor using acoustic feedback

    NASA Technical Reports Server (NTRS)

    Rice, Edward J. (Inventor)

    1995-01-01

    The present invention generally relates to providing an improved jet mixer noise suppressor for high speed jets that rapidly mixes high speed air flow with a lower speed air flow, and more particularly, relates to an improved jet mixer noise suppressor that uses feedback of acoustic waves produced by the interaction of shear flow instability waves with an obstacle downstream of the jet nozzle.

  3. 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.

  4. Gyrator Operation Using Josephson Mixers

    NASA Astrophysics Data System (ADS)

    Abdo, Baleegh; Brink, Markus; Chow, Jerry M.

    2017-09-01

    Nonreciprocal microwave devices, such as circulators, are useful in routing quantum signals in quantum networks and protecting quantum systems against noise coming from the detection chain. However, commercial, cryogenic circulators, now in use, are unsuitable for scalable superconducting quantum architectures due to their appreciable size, loss, and inherent magnetic field. We report on the measurement of a key nonreciprocal element, i.e., the gyrator, which can be used to realize a circulator. Unlike state-of-the-art gyrators, which use a magneto-optic effect to induce a phase shift of π between transmitted signals in opposite directions, our device uses the phase nonreciprocity of a Josephson-based three-wave-mixing device. By coupling two of these mixers and operating them in noiseless frequency-conversion mode, we show that the device acts as a nonreciprocal phase shifter whose phase shift is controlled by the phase difference of the microwave tones driving the mixers. Such a device could be used to realize a lossless, on-chip, superconducting circulator suitable for quantum-information-processing applications.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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.

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

    SciTech Connect

    Hatchell, Brian K.; Lewis, Benjamin E.; Randolph, John D.; Johnson, Marshall

    2001-03-01

    In FY 1998, pulsating mixer pump technology consisting of a jet mixer powered by a reciprocating air supply was selected for deployment in one of the Gunite and Associated Tanks (GAAT) 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. 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. This deployment is expected to save costs 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.

  16. Scalar transport in inline mixers with spatially periodic flows

    NASA Astrophysics Data System (ADS)

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

    2017-01-01

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

  17. 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.

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

    DOEpatents

    Shockling, L.A.

    1991-09-10

    An electrochemical apparatus is made having a generator section containing electrochemical cells, a fresh gaseous feed fuel inlet, a gaseous feed oxidant inlet, and at least one hot gaseous spent fuel recirculation channel, where the spent fuel recirculation channel, passes from the generator chamber to combine with the fresh feed fuel inlet to form a reformable mixture, where a reforming chamber contains an outer portion containing reforming material, an inner portion preferably containing a mixer nozzle and a mixer-diffuser, and a middle portion for receiving spent fuel, where the mixer nozzle and mixer-diffuser are preferably both within the reforming chamber and substantially exterior to the main portion of the apparatus, where the reformable mixture flows up and then backward before contacting the reforming material, and the mixer nozzle can operate below 400 C. 1 figure.

  19. 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.

  20. 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.

  1. Electrochemical cell apparatus having an exterior fuel mixer nozzle

    DOEpatents

    Reichner, P.; Doshi, V.B.

    1992-12-08

    An electrochemical apparatus is made having a generator section containing electrochemical cells, a fresh gaseous feed fuel inlet, a gaseous feed oxidant inlet, and at least one hot gaseous spent fuel recirculation channel, where the spent fuel recirculation channel, a portion of which is in contact with the outside of a mixer chamber, passes from the generator chamber to combine with the fresh feed fuel inlet at the entrance to the mixer chamber, and a mixer nozzle is located at the entrance to the mixer chamber, where the mixer chamber connects with the reforming chamber, and where the mixer-diffuser chamber and mixer nozzle are exterior to and spaced apart from the combustion chamber, and the generator chamber, and the mixer nozzle can operate below 400 C. 2 figs.

  2. 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.

  3. 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.

  4. 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".

  5. 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.

  6. 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...

  7. 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 support...

  8. 21 CFR 888.4210 - Cement mixer for clinical use.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

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

  9. 21 CFR 888.4210 - Cement mixer for clinical use.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

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

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

    Code of Federal Regulations, 2012 CFR

    2012-04-01

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

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

    Code of Federal Regulations, 2013 CFR

    2013-04-01

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

  12. 21 CFR 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...

  13. 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...

  14. 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...

  15. 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...

  16. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2017-05-01

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

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. Tunnel-Junction Mixers Perform Well At 205 GHz

    NASA Technical Reports Server (NTRS)

    Javadi, Hamid H. S.; Mcgrath, William R.; Cypher, Scott R.; Bumble, Bruce; Leduc, Henry G.; Hunt, Brian D.

    1995-01-01

    Superconductor-Insulator Superconductor (SIS) tunnel junctions made of NbN/MgO/NbN and Nb/AlOx/Nb, with cross-sectional areas of about 0.30 and 0.25 micrometer(Sup2) respectively, fabricated and tested for use as mixers at frequencies near 205 GHz. Cross sections must be small to make capacitances of devices acceptably small for operation at this frequency. NbN and Nb good materials choices as superconductors because of high energy gap, and mechanically and electrically rugged and chemically stable.

  3. 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.

  4. 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

  5. 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

  6. Low-Noise Thz Niobium SIS Mixers

    NASA Astrophysics Data System (ADS)

    Bin, Mei

    1997-09-01

    This thesis describes the development of low-noise heterodyne receivers at THz frequencies for submillimeter astronomy using Nb-based superconductor-insulator-superconductor (SIS) tunneling junctions. The mixers utilize a quasi-optical configuration which consists of a planar twin-slot antenna and antisymmetrically-fed two-junctions on an antireflection-coated silicon hyperhemispherical lens. On-chip integrated tuning circuits, in the form of microstrip lines, are used to obtain maximum coupling efficiency in the designed frequency band. To reduce the rf losses in the integrated tuning circuits above the superconducting Nb gap frequency (~700 GHz), normal-metal Al is used to replace Nb as the tuning circuits. To account the rf losses in the microstrip lines, we calculated the surface impedance of the Al films using the nonlocal anomalous skin effect for finite thickness films. Nb films were calculated using the Mattis-Bardeen theory in the extreme anomalous limit. Our calculations show that the losses of the Al and Nb microstrip lines are about equal at 830 GHz. For Al-wiring and Nb-wiring mixers both optimized at 1050 GHz, the RF coupling efficiency of Al-wiring mixer is higher than that of Nb-wiring one by almost 50%. We have designed both Nb-wiring and Al-wiring mixers below and above the gap frequency. A Fourier transform spectrometer (FTS) has been constructed especially for the study of the frequency response of SIS receivers. This FTS features large aperture size (10 inch) and high frequency resolution (114 MHz). The FTS spectra, obtained using the SIS receivers as direct detectors on the FTS, agree quite well with our theoretical simulations. We have also, for the first time, measured the FTS heterodyne response of an SIS mixer at sufficiently high resolution to resolve the LO and the sidebands. Heterodyne measurements of our SIS receivers with Nb-wiring or Al-wiring have yielded results which are among the best reported to date for broadband heterodyne

  7. 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

  8. 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

  9. 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

  10. 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.

  11. 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.

  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. 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.

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

    NASA Astrophysics Data System (ADS)

    Rongjiang, Liu; Guiliang, Guo; Yuepeng, Yan

    2013-03-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

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

  18. 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.

  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. 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.

  1. 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.

  2. 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.

  3. 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.

  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. Liquid-Gas Mixer and Turbulator Therefor

    NASA Technical Reports Server (NTRS)

    Brown, Christopher James (Inventor)

    2017-01-01

    Disclosed is a liquid-gas mixer including a central passageway provided about an injector axis, and first and second gas passageways. The first gas passageway is radially outward of the central passageway and radially inward of the second gas passageway. A turbulator is provided between the first and second gas passageways, and includes a plurality of first disturbance generators and a plurality of second disturbance generators. The first and second disturbance generators are provided about the turbulator in an alternating arrangement.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. 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

  12. 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

  13. 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

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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

  19. 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.

  20. 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

  1. 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.

  2. Terahertz hot electron bolometer waveguide mixers for GREAT

    NASA Astrophysics Data System (ADS)

    Pütz, P.; Honingh, C. E.; Jacobs, K.; Justen, M.; Schultz, M.; Stutzki, J.

    2012-06-01

    Context. Supplementing the publications based on the first-light observations with the German REceiver for Astronomy at Terahertz frequencies (GREAT) on SOFIA, we present background information on the underlying heterodyne detector technology. This Letter complements the GREAT instrument Letter and focuses on the mixers itself. Aims: We describe the superconducting hot electron bolometer (HEB) detectors that are used as frequency mixers in the L1 (1400 GHz), L2 (1900 GHz), and M (2500 GHz) channels of GREAT. Measured performance of the detectors is presented and background information on their operation in GREAT is given. Methods: Our mixer units are waveguide-based and couple to free-space radiation via a feedhorn antenna. The HEB mixers are designed, fabricated, characterized, and flight-qualified in-house. We are able to use the full intermediate frequency bandwidth of the mixers using silicon-germanium multi-octave cryogenic low-noise amplifiers with very low input return loss. Results: Superconducting HEB mixers have proven to be practical and sensitive detectors for high-resolution THz frequency spectroscopy on SOFIA. We show that our niobium-titanium-nitride (NbTiN) material HEBs on silicon nitride (SiN) membrane substrates have an intermediate frequency (IF) noise roll-off frequency above 2.8 GHz, which does not limit the current receiver IF bandwidth. Our mixer technology development efforts culminate in the first successful operation of a waveguide-based HEB mixer at 2.5 THz and deployment for radioastronomy. A significant contribution to the success of GREAT is made by technological development, thorough characterization and performance optimization of the mixer and its IF interface for receiver operation on SOFIA. In particular, the development of an optimized mixer IF interface contributes to the low passband ripple and excellent stability, which GREAT demonstrated during its initial successful astronomical observation runs.

  3. 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.

  4. 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.

  5. 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.

  6. Physical Attributes of Pulse Jet Mixer Operation

    SciTech Connect

    Kuhn, William L.; Rector, David R.; Bamberger, Judith A.; Minette, Michael J.

    2013-07-07

    Vessels mixed using pulse jet mixers that produce a periodic, rather than steady, flow present challenges with respect to modeling slurry mixing. A PJM is a cylindrical tank within the mixed tank that has a conical bottom with an orifice through which process fluid cyclically enters and is expelled forcefully by pressurizing the air space above the liquid in the PJM. Between pulses, some of the solids settle from the slurry, which nominally is a failure in mixing, but during the pulses (if operated to attain bottom clearing conditions), all of the solids are resuspended and made available for processing or transfer. Overall, mixing is successful if the solids are processed and removed from the vessel as needed when averaged over repeated PJM cycles. This paper describes the physics of pulse jet mixing process based on physical observation during experiments and analysis of experimental concentration profile data obtained during the mixing cycle.

  7. Two-Tone Intermodulation in Diode Mixers,

    DTIC Science & Technology

    1986-09-30

    PAOC(Vhn DO1 Entered) J6 4 Pr -’,4. *J *4~-444 4 *~ 4 P*. * 44*44 . J. *o. PREFACE The author wishes to thank R. M. Gowin for assistance with the...fabrica- tion of the mixers, W. A. Garber for measuring the diode C/ V characteristic, and M. McColl, W. A. Johnson, and F. L. Vernon for reading and...current 1%.’, and capacitive charge Q( V ’) are given by the well-known • "expressions ’-:jex q.’Y 7 KTI I’ 1 0exp(6 V ) (i) Q, ,= -2 C. I - V / ~ 𔃼(2) where

  8. 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.

  9. 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.

  10. 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

  11. 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.

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

    PubMed

    Yamaga, Yoshio; Kanatani, Mitsugu; Nomura, Shuichi

    2015-01-01

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

  13. 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

  14. 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

  15. 47. Pouring deck columns, steampowered concrete mixer at center; direction ...

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

    47. Pouring deck columns, steam-powered concrete mixer at center; direction of view not clear, but probably to north. - Parks Bar Bridge, Spanning Yuba River at State Highway 20, Smartville, Yuba County, CA

  16. 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.

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

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

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

  18. Pulsed column and mixer-settler applications in solvent extraction

    NASA Astrophysics Data System (ADS)

    Vancas, Mark F.

    2003-07-01

    Pulsed columns and mixer-settlers are the solvent extraction contactors used most frequently in the minerals industry. Each contactor has inherent advantages and disadvantages that can be utilized to create the optimum processing plant for a given mineral.

  19. 35. JL photographer, summer 1978, general view of chemical mixer ...

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

    35. JL photographer, summer 1978, general view of chemical mixer Baldwin Filtration plant - Division Avenue Pumping Station & Filtration Plant, West 45th Street and Division Avenue, Cleveland, Cuyahoga County, OH

  20. 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.

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

    DTIC Science & Technology

    1993-02-01

    Materials Research Laboratoryv Cordite Avenue, Maribyrnong. Victoria, 3032 Australia Telephone: (03) 2468111 Fax: (03) 246 8999 © Commonwealth of Australia...that the red valve on the small red bypass line above the branch tee to the chiller is closed. - In the Mixer Bay, ensure that the drench nozzle caps...drench nozzle caps, Outside the Mixer Bay door, on the north face of the building, open the bleed v’,lve. Open the red BYPASS valve near the chiller

  2. Embedding impedance approximations in the analysis of SIS mixers

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  3. 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.

  4. 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.

  5. 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.

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

    PubMed

    Ferraris, C 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.

  7. 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

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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

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

    PubMed

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

    2015-12-01

    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.

  15. Experiments on high bypass internal mixer nozzle jet noise

    NASA Technical Reports Server (NTRS)

    Goodykoontz, J. H.

    1982-01-01

    Model scale jet noise data are presented for a variety of internal lobed mixer nozzle configurations for take off power settings in a static environment. The results are presented for a 17.5 cm diameter fan nozzle to show the effect on noise levels caused by changes in geometric shape of the internal, or core flow, nozzle. The geometric variables include the lobe discharge angle, the number of lobes, spacing between the center plug and lobe valley, lobe side wall shape and axial contour of the lobes. An annular plug core flow nozzle was also tested and is used as a baseline for comparative purposes. Comparison of data from the internal lobed configurations showed that for comparative effect, in terms of the effect on full scale perceived noise levels, was caused by a change in the lobe discharge angle. The results showed that increasing the discharge angle caused an increase as large as 7 dB in sound pressure levels in the high frequency portion of the spectra. Changes in the other geometric variables cause negligible effects.

  16. 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

  17. 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.

  18. Reciprocating flow-based centrifugal microfluidics mixer.

    PubMed

    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

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. AEA Fluidic Pulse Jet Mixer. Innovative Technology Summary Report

    SciTech Connect

    1999-08-01

    AEA's Fluidic Pulse Jet Mixer was developed to mix and maintain the suspension of solids and to blend process liquids. The mixer can be used to combine a tank's available supernate with the sludge into a slurry that is suitable for pumping. The system uses jet nozzles in the tank coupled to a charge vessel. Then, a jet pump creates a partial vacuum in the charge vessel allowing it to be filled with waste. Next, air pressure is applied to the charge vessel, forcing sludge back into the tank and mixing it with the liquid waste. When the liquid waste contains 10% solids, a batch is pumped out of the tank.

  9. 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

  10. 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...

  11. 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...

  12. 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...

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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

  18. 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...

  19. 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...

  20. 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.

  1. 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.

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

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

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

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

    NASA Astrophysics Data System (ADS)

    Zheleva, I.; Lecheva, A.

    2015-10-01

    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. 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.

  5. 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, Dale 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

  6. 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.

  7. 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

  8. 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

  9. 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

  10. 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.

  11. A novel millimetre-wave gallium arsenide beam-lead mixer diode with cutoff frequency greater than 2 THz

    NASA Astrophysics Data System (ADS)

    Huang, Hsien-Ching; Swarup, Arvind; Henderson, Richard

    1991-04-01

    A low-parasitic-capacitance beam-lead Schottky diode has been developed for millimeter-wavelength mixer applications from 30-110 GHz. It has a novel structure that incorporates a polyimide film to support the beam leads and the GaAs active area. Typical devices have an ideality factor of 1.12, a parasitic capacitance of 10 fF, a zero-bias-junction capacitance of 20 fF, a series resistance of 2.5 ohms, and hence a figure of merit cutoff frequency of over 3 THz. Diodes tested in production mixers at 36 GHz have yielded a conversion loss of 5.14 dB. The devices, fabricated by repeatable production techniques, are mechanically rugged and suitable for qualification to space and defense standards.

  12. Design, Implementation, Simulation, and Visualization of a Highly Efficient RIM Microfluidic Mixer for Rapid Freeze-Quench of Biological Samples

    PubMed Central

    Schmidt, Bryan; Mahmud, Goher; Soh, Siowling; Kim, Sun Hee; Page, Taylor; O’Halloran, Thomas V.; Grzybowski, Bartosz A.; Hoffman, Brian M.

    2011-01-01

    Rapid freeze-quench (RFQ) trapping of short-lived reaction intermediates for spectroscopic study plays an important role in the characterization of biological reactions. Recently there has been considerable effort to achieve submillisecond reaction deadtimes. We present here a new, robust, high-velocity microfluidic mixer that enables such rapid freeze-quenching. It is a based on the mixing method of two impinging jets commonly used in reaction injection molding (RIM) of plastics. This method achieves efficient mixing by inducing chaotic flow at relatively low Reynolds numbers (Re =140). We present the first mathematical simulation and microscopic visualization of mixing in such RFQ micromixers, the results of which show that the impinging solutions efficiently mix within the mixing chamber. These tests, along with a practical demonstration in a RFQ setup that involves copper wheels, show this new mixer can in practice provide reaction deadtimes as low as 100 microseconds. PMID:22180701

  13. Design, Implementation, Simulation, and Visualization of a Highly Efficient RIM Microfluidic Mixer for Rapid Freeze-Quench of Biological Samples.

    PubMed

    Schmidt, Bryan; Mahmud, Goher; Soh, Siowling; Kim, Sun Hee; Page, Taylor; O'Halloran, Thomas V; Grzybowski, Bartosz A; Hoffman, Brian M

    2011-02-11

    Rapid freeze-quench (RFQ) trapping of short-lived reaction intermediates for spectroscopic study plays an important role in the characterization of biological reactions. Recently there has been considerable effort to achieve submillisecond reaction deadtimes. We present here a new, robust, high-velocity microfluidic mixer that enables such rapid freeze-quenching. It is a based on the mixing method of two impinging jets commonly used in reaction injection molding (RIM) of plastics. This method achieves efficient mixing by inducing chaotic flow at relatively low Reynolds numbers (Re =140). We present the first mathematical simulation and microscopic visualization of mixing in such RFQ micromixers, the results of which show that the impinging solutions efficiently mix within the mixing chamber. These tests, along with a practical demonstration in a RFQ setup that involves copper wheels, show this new mixer can in practice provide reaction deadtimes as low as 100 microseconds.

  14. Velocity and turbulence characteristics of isothermal lobed mixer flows

    SciTech Connect

    Koutmos, P.; McGuirk, J.J.

    1995-12-01

    This work describes an experimental and computational study of flows in model multilobed mixers. Laser Velocimetry was used to obtain the velocity and turbulence fields in the downstream mixing duct. Flow development was quantified by examination of the large cross-plane velocities whose direction implied the formation of two streamwise vortices per lobe. A change from coplanar to scarfed geometry increased vortex strength by 25 percent. Vortex cell formation, roll-up and breakdown to fine scale mixing was attained within a distance of 5 lobe heights. The computational investigation of the coplanar configuration adopted a non-aligned mesh to solve the 3-D Reynolds averaged Navier-Stokes equations. The calculations of the lobe and mixing duct flows were coupled to predict the complete mixer. Comparisons between measurements and calculations using a standard {kappa}-{epsilon} model suggested good qualitative agreement with maximum disagreement of about 20 percent in peak radial velocities.

  15. 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.

  16. 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

  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

    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.

  19. 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.

  20. 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

  1. 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.

  2. 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

  3. Third-Order Intermodulation in a Micromechanical Thermal Mixer

    DTIC Science & Technology

    2005-12-01

    rier frequency. A variant of the Duffing oscillator model and finite element modeling are used to analyze the origin of nonlinearities in the...micromechanical system. [1503] Index Terms—Bandpass filter, Duffing oscillator , intermediate frequency, microelectromechanical systems (MEMS), mixer, non...input intercept point of +30 dBm for interferers spaced at a 50-kHz offset from the carrier frequency. A variant of the Duffing oscillator model and

  4. 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.

  5. 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.

  6. 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.

  7. The influence of operational parameters and feed preparation in a convective batch ribbon powder mixer.

    PubMed

    Yeow, Sin Tung; Shahar, Asnawi; Abdul Aziz, Norashikin; Anuar, Mohd Shamsul; Yusof, Yus Aniza; Taip, Farah Saleena

    2011-01-01

    To investigate the effect of feed preparation characteristics and operational parameters on mixing homogeneity in a convective batch ribbon mixer. Lactose 100M, lactose 200M, ascorbic acid, and zinc oxide powders were used for the mixing study. Operational parameters studied were rotational speed and mixing time. The feed preparations studied were the use of preblending and the particle size of the feed materials. The blends of ascorbic acid, zinc oxide, and lactose were prepared with preblending and without preblending, prior to mixing at different blender rotation speeds and mixing times. Chemical tests were performed to measure the homogeneity of the ascorbic acid in the model mixture. With preblending, a mixture with lactose 200M achieved the required homogeneity in a shorter period of time at a lower rotational speed. The results indicated that the homogeneity of the mixtures was influenced by the blender rotation speed and mixing time. Better mixing can be obtained with higher rotation speeds and longer mixing time. It was also observed that preblending and smaller feed particle size achieved the required homogeneity in a shorter period of time at a lower rotational speed. These results illustrate that using binders with a smaller particle size and a preblending technique improves the mixing process in a convective batch ribbon powder mixer. However, prolonged periods of high-speed mixing will lead to mixture segregation.

  8. The influence of operational parameters and feed preparation in a convective batch ribbon powder mixer

    PubMed Central

    Yeow, Sin Tung; Shahar, Asnawi; Aziz, Norashikin Abdul; Anuar, Mohd Shamsul; Yusof, Yus Aniza; Taip, Farah Saleena

    2011-01-01

    Purpose To investigate the effect of feed preparation characteristics and operational parameters on mixing homogeneity in a convective batch ribbon mixer. Methods Lactose 100M, lactose 200M, ascorbic acid, and zinc oxide powders were used for the mixing study. Operational parameters studied were rotational speed and mixing time. The feed preparations studied were the use of preblending and the particle size of the feed materials. The blends of ascorbic acid, zinc oxide, and lactose were prepared with preblending and without preblending, prior to mixing at different blender rotation speeds and mixing times. Chemical tests were performed to measure the homogeneity of the ascorbic acid in the model mixture. Results With preblending, a mixture with lactose 200M achieved the required homogeneity in a shorter period of time at a lower rotational speed. Conclusion The results indicated that the homogeneity of the mixtures was influenced by the blender rotation speed and mixing time. Better mixing can be obtained with higher rotation speeds and longer mixing time. It was also observed that preblending and smaller feed particle size achieved the required homogeneity in a shorter period of time at a lower rotational speed. These results illustrate that using binders with a smaller particle size and a preblending technique improves the mixing process in a convective batch ribbon powder mixer. However, prolonged periods of high-speed mixing will lead to mixture segregation. PMID:22162640

  9. 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.

  10. 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).

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

    NASA Astrophysics Data System (ADS)

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

    2015-11-01

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

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. MICROFLUIDIC MIXERS FOR THE INVESTIGATION OF PROTEIN FOLDING USING SYNCHROTRON RADIATION CIRCULAR DICHROISM SPECTROSCOPY

    SciTech Connect

    Kane, A; Hertzog, D; Baumgartel, P; Lengefeld, J; Horsley, D; Schuler, B; Bakajin, O

    2006-03-20

    The purpose of this study is to design, fabricate and optimize microfluidic mixers to investigate the kinetics of protein secondary structure formation with Synchrotron Radiation Circular Dichroism (SRCD) spectroscopy. The mixers are designed to rapidly initiate protein folding reaction through the dilution of denaturant. The devices are fabricated out of fused silica, so that they are transparent in the UV. We present characterization of mixing in the fabricated devices, as well as the initial SRCD data on proteins inside the mixers.

  20. 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.

  1. 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.

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

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. S-I-S mm-Wave Mixers and Detectors.

    DTIC Science & Technology

    1983-10-01

    NAME AND ADDRESS 10. PROGRAM ELEMENT. PROJECT , TASK Sperry Research Center AREA & WORK UNIT NUMBERS 100 North Road Sudbury, Mass. 01776 I1...HOAD-i34 762 s-I-s MM-WRYt MIIXERS AND DETECTORS(U) SPERRY RESEARCH i/i CENTER SUDBURY MR D WI JILLIE ET AL. OCT 83 SRC-CR-83-33 N86814-81-C-2525...1963 A, * -’ " - .- " .° • " : - . " 722 j’T- S-I-S mm-WAVE MIXERS AND DETECTORS 0. W. Jillie, H. Kroger, L, N. Smith and D. M. Shaw Sperry Research

  8. 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.

  9. 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.

  10. 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.

  11. 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.

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

    NASA Technical Reports Server (NTRS)

    Kerr, A. R.

    1979-01-01

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

  13. 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.

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

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  15. 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

  16. 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...

  17. 26 CFR 48.4061-1 - Temporary regulations with respect to floor stock refunds or credits on cement mixers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

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

  18. 26 CFR 48.4061-1 - Temporary regulations with respect to floor stock refunds or credits on cement mixers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

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

  19. 26 CFR 48.4061-1 - Temporary regulations with respect to floor stock refunds or credits on cement mixers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

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

  20. Modification of wheat straw in a high-shear mixer

    SciTech Connect

    Carr, M.E.; Doane, W.M.

    1984-01-01

    Wheat straw (WS) was treated in a pilot-scale continuous mixer to disrupt the lignin-hemicellulose-cellulose (LHC) complex. An efficient and practical method was desired to remove lignin and hemicellulose (pentosans) rapidly and efficiently from the lignocellulose complex and to make the cellulose accessible to enzymatic hydrolysis. Milled WS in the presence of various chemicals in aqueous solutions was extruded from the mixer under several processing conditions. Chemicals used were sodium hydroxide (NaOH), sodium sulfide (Na/sub 2/S), anthraquinone (AQ), anthrahydroquinone (AHQ), hexamethylenediamine (HMDA), hexamethylenetetramine (HMTA), hydrogen peroxide (H/sub 2/O/sub 2/), and ferrous ammonium sulfate (FAS), which were used alone and in selected combinations. Concomitantly, WS was treated in laboratory batches using similar reaction conditions, except for mixing shearing. In extrusion treatments of WS at 20% concentration at 97/sup 0/C for 5.5 min with NaOH (15.7%, dry WS basis), NaOH (15.7%) + AHQ (0.3%), and NaOH (12.7%) + Na/sub 2/S (5.0%), 64-72% of the WS lignin and 36-43% of the pentosans were removed from aqueously washed extrudates (residues). This compares with 46-56% and 23-27%, respectively, for batch treatments. AHQ and Na/sub 2/S enhanced delignification. Cellulase treatment of the residues, which contai

  1. Analysis of CMOS Transconductance Amplifiers for Sampling Mixers

    NASA Astrophysics Data System (ADS)

    Li, Ning; Chaivipas, Win; Okada, Kenichi; Matsuzawa, Akira

    In this paper the transfer function of a system with windowed current integration is discussed. This kind of integration is usually used in a sampling mixer and the current is generated by a transconductance amplifier (TA). The parasitic capacitance (Cp) and the output resistance of the TA (Ro,TA) before the sampling mixer heavily affect the performance. Calculations based on a model including the parasitic capacitance and the output resistance of the TA is carried out. Calculation results show that due to the parasitic capacitance, a notch at the sampling frequency appears, which is very harmful because it causes the gain near the sampling frequency to decrease greatly. The output resistance of the TA makes the depth of the notches shallow and decreases the gain near the sampling frequency. To suppress the effect of Cp and Ro,TA, an operational amplifier is introduced in parallel with the sampling capacitance (Cs). Simulation results show that there is a 17dB gain increase while Cs is 1pF, gm is 9mS, N is 8 with a clock rate of 800MHz.

  2. A Planar Microfluidic Mixer Based on Logarithmic Spirals

    PubMed Central

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

    2013-01-01

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

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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

  11. 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.

  12. 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.

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

    NASA Technical Reports Server (NTRS)

    Paterson, R. W.

    1982-01-01

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

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. A microfluidic mixer with grooves placed on the top and bottom of the channel.

    PubMed

    Howell, Peter B; Mott, David R; Fertig, Stephanie; Kaplan, Carolyn R; Golden, Joel P; Oran, Elaine S; Ligler, Frances S

    2005-05-01

    A new microfluidic mixer is presented consisting of a rectangular channel with grooves placed in the top and bottom. This not only increases the driving force behind the lateral flow, but allows for the formation of advection patterns that cannot be created with structures on the bottom alone. Chevrons, pointing in opposite directions on the top and bottom, are used to create a pair of vortices positioned side by side. Stripes running the width of the channel generate a pair of vertically stacked vortices. Computational fluid dynamics (CFD) simulations are used to model the behavior of the systems and provide velocity maps at cross-sections within the mixer. Experiments demonstrate the mixing that results when two segregated species enter the mixer side-by-side and pass through two cycles of the mixer (i.e., two alternating sets of four stripes and four chevrons).

  20. 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.

  1. 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.

  2. 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.

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

    PubMed

    Yong, Shan; JingZhou, Zhang; Yameng, Wang

    2014-11-01

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

  4. 670-GHz Schottky Diode-Based Subharmonic Mixer with CPW Circuits and 70-GHz IF

    NASA Technical Reports Server (NTRS)

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

    2012-01-01

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

  5. 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.

  6. 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.

  7. 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.

  8. Temperature-controlled continuous production of all-trans retinoic acid-loaded solid lipid nanoparticles using static mixers

    NASA Astrophysics Data System (ADS)

    Shao, Wenyao; Yan, Mengwen; Chen, Tingting; Chen, Yuqing; Xiao, Zongyuan

    2017-04-01

    This work aims to develop a temperature-controlled continuous solvent emulsification-diffusion process to synthesize all-trans retinoic acid (ATRA)-loaded solid lipid nanoparticles (SLNs) using static mixers. ATRA-loaded SLNs of around 200 nm were obtained when the flow rates of the organic and aqueous phases were 50 ml min-1 and 500 ml min-1, respectively. It was found that the lipid concentration played a dominant role in the size of the obtained SLNs, and higher drug concentration resulted in relatively low entrapment efficiency. The encapsulation of ATRA in the SLNs was effective in improving its stability according to the photo-degradation test. The in vitro release of SLN was slow without an initial burst. This study demonstrates that the solvent emulsification-diffusion technique with static mixing is an effective method of producing SLNs, and could easily be scaled up for industrial applications. Highlights Higher lipid concentration leads to larger SLNs. SLN transformation occurs due to Ostwald ripening. The ATRA-loaded SLNs around 200 nm were successfully produced with static mixers. ATRA-loaded SLNs show better stability towards sunlight. ATRA in SLNs exhibited a relatively slow release rate without a significant initial burst.

  9. 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.

  10. 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.

  11. 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.

  12. Russian Pulsating Mixer Pump. Innovative Technology Summary Report

    SciTech Connect

    2002-03-01

    This sludge mixing/mobilization system was developed in Russia. A prototype system was evaluated by the Tanks Focus Area (TFA) and Industry and University Programs (INDP). The Russian Pulsating Mixer Pump showed promise for mixing highly viscous sludges. This project is to refine the system design (especially the control subsystem) and manufacture the system in Russia in accordance with quality standards required for deployment in radioactive waste storage tanks. Specifications and requirements are being developed by the TFA and INDP. The requirements may call for two or three of the sludge mixing systems to be delivered to Oak Ridge. DOE-Oak Ridge and the Oak Ridge National Laboratory will deploy the pulsating mixing pump system in their Gunite Tanks. These tanks are being emptied and cleaned prior to closure. Oak Ridge has deployed a number of innovative technologies in these efforts. If successful at Oak Ridge, the pulsating mixing pump system has potential application at several other DOE sites, including Savannah River, Hanford, and Idaho.

  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. 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.

  17. 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.

  18. 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.

  19. 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.

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

    NASA Technical Reports Server (NTRS)

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

    1978-01-01

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

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

    PubMed

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

    2010-01-01

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

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

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

    PubMed

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

    2012-02-01

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

  8. A low voltage low power up-conversion mixer for WSN application

    NASA Astrophysics Data System (ADS)

    Chenjian, Wu; Zhiqun, Li; Ge, Sun

    2014-04-01

    This paper presents an up-conversion mixer for 2.4-2.4835 GHz wireless sensor networks (WSN) in 0.18 μm RF CMOS technology. It was based on a double-balanced Gilbert cell type, with two Gilbert cells having quadrature modulation applied. Current-reuse and cross positive feedback techniques were applied in the mixer to boost conversion gain; the current source stage was removed from the mixer to improve linearity. Measured results exhibited that under a 1 V power supply, the conversion gain was 5 dB, the input referred 1 dB compression point was -11 dBm and the IIP3 was -0.75 dBm, while it only consumed 1.4 mW.

  9. 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).

  10. 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).

  11. 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.

  12. 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.

  13. A terahertz monolithic integrated resonant tunneling diode oscillator and mixer circuit

    NASA Astrophysics Data System (ADS)

    Diebold, Sebastian; Tsuruda, Kazuisao; Kim, Jae-Young; Mukai, Toshikazu; Fujita, Masayuki; Nagatsuma, Tadao

    2016-04-01

    In this paper, we demonstrate the monolithic integration of two resonant tunneling diodes (RTD) to make a THz mixer circuit. The circuit uses two RTDs, which are integrated in one carrier substrate. The RTDs are biased independently. The fist RTD operates as an oscillator and provides the local oscillator signal for the second RTD operating as a mixer. The measurements demonstrate that a monolithic integration of several RTDs in one substrate is feasible. This offers new possibilities for RTD based wireless communication and sensing systems.

  14. 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).

  15. 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.

  16. 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.

  17. 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.

  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. 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.

  1. 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

  2. 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

  3. 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).

  4. 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.

  5. 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.

  6. S-i-s mm-wave mixers and detectors. Final report

    SciTech Connect

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

    1983-10-01

    This program is an effort to achieve the ultimate goal of fabricating refractory superconducting S-I-S mixer devices for operation in mm-wave receivers in the quantum mode and in the 8-10 K temperature range. The following progress has been made toward the above goal: (1) development of in-house capability of depositing niobium carbonitride films (Nb (x) N(y) of device quality with transition temperatures to approx. 16 K; (2) development of NbC(x)N(y):aSi:Nb and NbC(x)N(y):Ge:Nb devices of very high quality; (3) fabrication and successful operation of niobium based S-I-S mixer chips; and (4) fabrication and evaluation of aSi and Ge barrier all-NbC(x)N(y) devices. NbC(x)N(y):Ge:Nb devices have been fabricated with chemical vapor deposited (CVD) polycrystalline arsenic-doped germanium barriers. All-Nb-S-I-S mixer chips were fabricated and sent to Goddard Institute for Space Studies to be evaluated. The noise temperature was approx. 60 K and the conversion loss of 5 dB. These results are comparable to Pb alloy junction results. A second-generation mixer was designed by GISS.

  7. 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...

  8. 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...

  9. 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

  10. Development of a Fast Microfluidic Mixer for Studies of Protein Folding KineticsFinal Report Cover Page

    SciTech Connect

    Bakajin, O

    2005-02-10

    We designed and fabricated mixing devices that will help us elucidate the mechanisms of protein folding through measurements of folding reaction rates. These devices can be used in studying of other biological systems and are compatible with various spectroscopic observation methods. The project involved development of fabrication processes and setup of a laboratory for assembly and characterization of microfluidic devices, as well as measurements of protein folding kinetics. We produced three variants of the mixer: (1) The ultra fast mixer for Foerster Resonance Energy Transfer measurements (described by Anal. Chem. Article UCRL-JRNL-206676) and MicroTAS Conference Proceedings article (UCRL-JC-153057 ) included in the report; (2) The ultra fast mixer for UV measurements (described by the poster presented at MicroTAS conference (UCRL-POST-207476) included in the report); and (3) The mixer for single molecule measurements (described by the Science article UCRL-JC-153057) included in the report. In these mixers, the channels are narrow, ranging from a few to hundreds of {micro}m, so that the flow is laminar and all of the mixing is achieved through diffusion. Our goal is to develop robust microfluidic mixer with at least 100 times lower consumption rate, shorter dead time and time resolution than commercially available mixers that would be compatible with most commonly used spectroscopic methods. We are also developing mixers that can be used in combination with single molecule spectroscopy. The mixers are used to study kinetics of fast protein folding reactions using bulk fluorescence and single molecule fluorescence resonance energy transfer techniques. Capabilities for microfluidic have been developed at BSNL that will be useful for studies of interactions of DNA with proteins and other projects such as the single molecule detector for detection of low concentration of toxins.

  11. 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

  12. 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

  13. A 2-GHz Low-Power Down-Conversion Mixer in 0.18-μm CMOS Technology

    NASA Astrophysics Data System (ADS)

    Chen, Jun-Da; Lin, Zhi-Ming; Row, Jeen-Sheen

    A low-voltage and low-power RF mixer for WCDMA applications is presented. The paper presents a novel topology mixer that leads to a better performance in terms of isolation and power consumption for low supply voltage. The measuring results of the proposed mixer achieve: 7dB power conversion gain, 10.4dB double side band (DSB) noise figure, -2dBm input third-order intercept point (IIP3), and the total dc power consumption of this mixer including output buffers is 2.2mW from a 1V supply voltage. The current output buffer is about 1.96mW, the excellent LO-RF, LO-IF and RF-IF isolation achieved up to 49dB, 39.5dB and 57.3dB, respectively.

  14. 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.

  15. 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.

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

    SciTech Connect

    WHITE, D.A.

    1999-12-29

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

  17. A wideband terahertz high-T c superconducting Josephson-junction mixer: electromagnetic design, analysis and characterization

    NASA Astrophysics Data System (ADS)

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

    2017-09-01

    This paper presents a wideband terahertz (THz) mixer based on a thin-film antenna-coupled high-temperature superconducting (HTS) YBa2Cu3O7-x (YBCO) step-edge Josephson junction. The HTS mixer enables the flexible harmonic mixing operation at multiple THz bands with the same microwave local oscillator (LO) source, and features very wide intermediate-frequency or instantaneous bandwidth. In order to optimize the frequency down-conversion performance of the mixer, systematic electromagnetic design and analysis have been carried out to improve the power coupling of THz radiation as well as wideband transmission of microwave signals. Experimental characterization of a fabricated device prototype has demonstrated that the mixer exhibits good performance at both the 200 GHz and 600 GHz bands. Detailed measurement results including the DC characteristics, LO pumping requirement, frequency response, mixing linearity and conversion gain are presented in this paper.

  18. Numerical analysis in the effects of blade's arrangement on the torque load characteristics of the three-blade planetary mixer

    NASA Astrophysics Data System (ADS)

    Liang, Jian; He, Ruibo; Zhan, Xiaobin; Li, Xiwen; Shi, Tielin

    2017-08-01

    The three-blade planetary mixer is one of the important solid propellant mixing equipment, the layout of blades will affect the blades' torque load and the power consumption. In this paper, the effects of the eccentric distance (Es=0˜16 mm), the solid blade form (two paddles, and four paddlers), and the blade arrangement (linear arrangement, triangle arrangement) on the blades' torque load are investigated during the mixer stirring the solid propellant process.

  19. An 85-115 GHz SIS Mixer Demonstrating Nearly Constant Dynamic Resistance

    NASA Astrophysics Data System (ADS)

    Shan, Wenlei; Li, Zhenqiang; Zhong, Jiaqiang; Shi, Shengcai

    2009-06-01

    We report the design and experiment results of 85-115 GHz SIS mixers that demonstrate nearly constant dynamic resistance and uniform conversion gain. The dynamic resistance close to 50 Omega allows stable bias and direct connection of the SIS mixer and the cryogenic low noise amplifier without an IF isolator. The tuning circuit consists of a single junction tuned by an equivalent shunt inductance and an impedance transformer used for impedance matching. Since the impedance transformer and the shunt inductance have opposite frequency-dependent admittances, we were able to eliminate the frequency-dependent components of the tuning circuit and managed to achieve nearly constant embedding impedance in the frequency range. Measurement results showing dynamic resistances ranging from 30 Omega to 50 Omega and conversion gain changing less than 3 dB reasonably agree with the simulations.

  20. 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.

  1. 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

  2. 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.

  3. Development of 460 GHz and Dual Polarization SIS Mixers for the Submillimeter Array

    NASA Astrophysics Data System (ADS)

    Li, Chao-Te; Liu, Kuan-Yu; Lu, Wei-Chun; Chiu, Chuang-Ping; Chen, Tse-Jun; Chen, Chong-Wen; Chang, Yung-Chin; Wang, Ming-Jye; Shi, Sheng-Cai

    2011-06-01

    A heterodyne receiver incorporating superconductor-insulator- superconductor (SIS) mixers has been designed to cover the frequency range from 400 to 520 GHz of the Submillimeter Array (SMA). Various tuning circuits have been employed to resonate out the geometric capacitance of the junction and provide impedance matching to the waveguide probe. Our measurements indicated that a receiver noise temperature of around 90 K, with the contributions from the input noise and intermediate frequency (IF) noise estimated to be around 60 K and 10 K, respectively. SIS mixers integrated with planar orthomode transducers (OMT) have also been designed at 345 GHz for dual polarization detections, and results from the 3-dimensional (3-D) electromagnetic (EM) simulations are presented.

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

    NASA Technical Reports Server (NTRS)

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

    1996-01-01

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

  5. 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.

  6. 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.

  7. 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

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

    NASA Technical Reports Server (NTRS)

    Kerr, A. R.

    1979-01-01

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

  9. 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.

  10. 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.

  11. 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.

  12. Planar Schottky barrier mixer diodes for space applications at submillimeter wavelengths

    NASA Technical Reports Server (NTRS)

    Bishop, W. L.; Crowe, T. W.; Mattauch, R. J.; Ostdiek, P. H.

    1991-01-01

    Available planar diodes for space-based applications at submillimeter wavelengths have not achieved either the required low junction capacitance or the low series resistance-junction capacitance product. Here, the development of a novel planar diode structure that overcomes both of these difficulties is outlined. The characteristics of these Schottky barrier mixer diodes are presented and electron micrographs are shown. The diode structure will allow planar technology to be extended throughout the submillimeter wavelength range.

  13. 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

  14. Rapid transesterification of micro-amount of lipids from microalgae via a micro-mixer reactor.

    PubMed

    Liu, Jiao; Chu, Yadong; Cao, Xupeng; Zhao, Yuchao; Xie, Hua; Xue, Song

    2015-01-01

    Fatty acid composition is an important physiological parameter of microalgae, which is taken as the third generation alternative resource of biodiesel. To boost microalgal research and applications, a convenient, rapid, and acid-catalyzed transesterification procedure that satisfies the demand for the analysis of the fatty acid composition of lipids with micro-scale samples in the high-throughput screening of microalgal strains is needed, along with the evaluation of the physiological status of microalgae in response to nutrient stress. The reaction conditions of transesterification via a micro-mixer reactor were optimized as follows: 90 °C reaction temperature, 20 min reaction time, 6:1 volume ratio of H2SO4-methanol to lipid-in-hexane, and a Y-type micro-mixer with a 20-m-long extended loop that has a 0.3 mm diameter. The minimum amount of sample was decreased to 30 µg lipids. The new approach was successfully applied to the fatty acid composition analysis of soybean oil and microalgal lipids. Definitely, it could be applied to acyl related oils from different sources. Here, we have developed a simple and rapid method for the analysis of the fatty acid composition of lipids. The new method requires less than 20 min for transesterification and a minimum of only 30 µg lipid sample. Furthermore, a high-throughput process can be easily realized by numbering up the micro-mixer reactors. The micro-mixer reactor has great potential for applications not only in large-scale biodiesel production but also for the micro-scale analysis of microalgae fatty acid compositions.

  15. 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.

  16. Dose rate calculations for the removal of the mixer pump from Tank 101 SY

    SciTech Connect

    Schwarz, R.A.

    1995-02-17

    Plans are currently being made for the removal of the mixer pump in tank 101 SY. Because the pump is contaminated with radioactive waste, it is essential that those involved in the pump removal operation have an indication of the expected dose rates when the pump is removed. Calculations were made to determine the dose rates for removing the pump, inserting the pump into a shipping container and filling the shipping container with either steel or lead shot for shielding.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

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

    PubMed Central

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

    2010-01-01

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

  2. Structural analysis: Flexible receiver yoke brace for the 241SY101 mixer pump

    SciTech Connect

    Jones, K.M.

    1994-09-09

    This report documents the structural analysis of the flexible-receiver yoke brace that will be used to maintain the mixer pump lifting yoke in a vertical position during the removal of the mixer pump from waste tank 241SY101. During the removal process, the crane is connected to a lifting yoke which is attached to the lifting on the mounting flange of the mixer pump. The pump then can be lifted from the tank. At one point in the removal procedure, the crane will be disconnected from the lifting yoke. At this time, it is possible for the lifting yoke to rotate around the pinned connection between it and the pump if it is subjected to a horizontal load. To prevent the rotation of the lifting yoke, the yoke brace was designed to maintain the yoke in a vertical position while it is disconnected from the crane. This analysis addressed the adequacy of the yoke brace to provide support for the lifting yoke during high winds and a seismic event. The results of this analysis show that, when subjected to a combined design wind and seismic load, the yoke brace design is acceptable to maintain the lifting yoke in a vertical position when the yoke is disconnected from the crane.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Waveguide Heterodyne Mixers at THz-Frequencies - Superconducting Hot Electron Bolometers on 2-micron Si3N4 Membranes for GREAT and CONDOR

    NASA Astrophysics Data System (ADS)

    Munoz, Pedro Pablo

    2007-04-01

    realized in this thesis by fabricating the mixer device on a thin (i.e. 2 micron) membrane layer deposited on a bulk silicon carrier wafer. The membrane is released by backside etching of the wafer after device fabrication. A large supporting frame is needed around the device for handling and contacting. A possible approach is to fabricate the frame and the mixer simultaneously on one wafer. In the process presented here the membrane-HEB devices and the supporting frames are fabricated separately avoiding the loss of wafer "real estate" for the support frames and thus allowing for up to 690 devices to be simultaneously produced on a single 30 mm square wafer. Fabricating many identical devices for arrays is possible even if many devices are damaged during fabrication. Further it is possible to test many different parameter-variations on one single wafer. The price to pay is a slightly more involved assembly procedure, which has been realized for the first time for 1.4 and 1.9 THz in this thesis. The fabrication of the phonon-cooled HEBs was fully realized at the KOSMA clean room facilities. The sputter deposition of ultra-thin NbTiN films with critical temperatures as high as 8.5 K is one of the technological highlights, already described at [1]. This thesis focused on the optimization of the contact interfaces between the electrodes and the ultrathin superconducting layer. Etching the interface previous to deposition of the electrodes leads to a better control over the interface. The effect of the etching parameters on the HEBs has been investigated. To restore the superconducting film properties that might be affected by the cleaning process, a NbTiN layer (20 nm) is deposited on top of the contact area. The additional superconducting layer between the bolometer thin film and the heat sinks has a positive effect on the mixer performance but introduced complications in the fabrication process which have been solved in this thesis. The fabricated waveguide HEB mixers on

  8. 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.

  9. 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

  10. 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.…

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

    PubMed

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

    2015-01-01

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

  13. 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.

  14. Acceptance test procedure, 241-SY-101 Flexible Receiver System, Phase III testing

    SciTech Connect

    Ritter, G.A.

    1994-11-21

    This Acceptance Test Procedure is for the 241-SY-101 Flexible Receiver System, Phase III Testing. This procedure will test the sealing integrity of the Flexible Receiver System to ensure that release of waste and aerosols will be minimized during the removal of the test mixer pump from tank SY-101.

  15. 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.

  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. 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.

  18. Aeroacoustic Characteristics of a Rectangular Multi-Element Supersonic Jet MIXER-EJECTOR Nozzle

    NASA Astrophysics Data System (ADS)

    Raman, G.; Taghavi, R.

    1997-10-01

    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 applications for noise suppression and thrust augmentation. In contrast to most prior experimental studies on ejectors that reported either aerodynamicoracoustic data, the present work documentsbothtypes of data. Information on the mixing, pumping, ejector wall pressure distribution, thrust augmentation and noise suppression characteristics of four simple, multi-element, jet mixer-ejector configurations is presented. The four configurations included the effect of ejector area ratio (AR=ejector cross-sectional area/total primary nozzle area) and the effect of non-parallel ejector walls. The configuration that produced the best noise suppression characteristics has also been studied in detail. The present results show that ejector configurations that produced the maximum pumping (secondary (induced) flow normalized by the primary flow) 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, one found that noise suppression trends correspond with those for pumping (per unit secondary area). 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 expandedMi(the Mach number that would have been attained under isentropic expansion). However, the noise suppression dependence on the mixing was apparent atMi=1·6. The above observations are justified by noting that the mixing at the ejector exit is not a strong factor in determining the radiated noise when noise produced internal to the ejector dominates the noise field outside the ejector.

  19. 3D printed microfluidic mixer for point-of-care diagnosis of anemia.

    PubMed

    Plevniak, Kimberly; Campbell, Matthew; Mei He

    2016-08-01

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

  20. 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.

  1. 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.

  2. 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.

  3. Noise measurements for various configurations of a model of a mixer nozzle externally blown flap system

    NASA Technical Reports Server (NTRS)

    Goodykoontz, J. H.; Wagner, J. M.; Sargent, N. B.

    1973-01-01

    Noise data were taken for variations to a large scale model of an externally blown flap lift augmentation system. The variations included two different mixer nozzles (7 and 8 lobes), two different wing models (2 and 3 flaps), and different lateral distances between the wing chord line and the nozzle centerline. When the seven lobe was used with the trailing flap in the 60 deg position, increasing the wing to nozzle distance had no effect on the sound level. When the eight lobe nozzle was used there was a decrease in sound level. With the 20 deg flap setting the noise level decreased when the distance was increased using either nozzle.

  4. 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).

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Reduction of pesticide exposure with protective clothing for applicators and mixers

    SciTech Connect

    Davies, J.E.; Freed, V.H.; Enos, H.F.; Duncan, R.C.; Barquet, A.; Morgade, C.; Peters, L.J.; Danauskas, J.X.

    1982-06-01

    Systemic pesticide illness in agricultural workers may result from excessive dermal exposure to pesticides. Workers who apply and mix pesticides (applicators and mixers) are not at special risk. Both acute and chronic exposures can occur from spillage or by environmental contamination of clothing. Two exposure assessment studies were conducted of Central Florida citrus grove workers who applied ethion daily. Measuring the percentage of penetration of ethion through clothing and measuring the daily urinary excretion of diethyl phosphate (DEP) were the techniques used to assess the protection afforded by changing daily to freshly laundered 100% cotton coveralls. Coveralls provided significantly greater protection than did regular clothing and the use of respirators.

  10. A Monolithic Dual-Gate MESFET Circuit for L-Band Mixers

    DTIC Science & Technology

    1990-06-01

    buffer were actually fabricated on two chips measuring 0.96 X 1.26 mm 2 and 0.96 X 0.60 mm 2 . Only three impedance conditions were defined as design... conditions . 2.4.3 Matching Networks Providing matching at all three ports of the mixer is always desirable. A match at the LO, RF, and IF frequencies at the... condition of the DGFET is difficult to characterize because the internal voltage at DI cannot be measured.[14] However, if the I-V characteristics of

  11. NMR parallel Q-meter with double-balanced-mixer detection for polarized target experiments

    SciTech Connect

    Boissevain, J.; Tippens, W.B.

    1983-01-01

    A constant-voltage, parallel-tuned nuclear magnetic resonance (NMR) circuit, patterned after a Liverpool design, has been developed for polarized target experiments. Measuring the admittance of the resonance circuit allows advantageous use of double-balanced mixer detection. The resonant circuit is tolerant of stray capacitance between the NMR coil and the target cavity, thus easing target-cell-design constraints. The reference leg of the circuit includes a voltage-controlled attenuator and phase shifter for ease of tuning. The NMR output features a flat background and has good linearity and stability.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2017-07-01

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

  1. ELECTROMAGNETISM, OPTICS, ACOUSTICS, HEAT TRANSFER, CLASSICAL MECHANICS, AND FLUID DYNAMICS: Effect of Viscosities on Mixing in A Patterned Micro Mixer

    NASA Astrophysics Data System (ADS)

    Hua, Shuo; Liu, Yang; Xu, You-Sheng

    2010-05-01

    The effect of viscosity and viscosity difference and boundary patterned slip on mixing in a micro mixer has been numerically studied using lattice Boltzmann method (LBM). The slip and no-slip ratio is not constant and varies irregularly, and viscosity is altered by changing the relaxation time in LBE equation. The slip boundary condition is simulated by specular reflection boundary and the no-slip boundary condition is simulated by bounce back boundary. It has been found that it is feasible to optimize the micro mixer design by combining the viscosity effect and boundary patterned ratio altogether.

  2. 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.

  3. Acceptance Test Report for Gamma Carts A and B

    SciTech Connect

    FULLER, P.J.

    2000-03-16

    Report of Shop Test of the Gamma Cart System to be used in the AZ-101 Mixer Pump Demonstration Test. Reports of the hardware and software tests. The objective of the testing was to verify in the shop that the hardware and software operated according to design specifications before field-testing and installation.

  4. 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.

  5. 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.

  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. 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.

  8. Optimization of a Continuous Hybrid Impeller Mixer via Computational Fluid Dynamics

    PubMed Central

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

    2014-01-01

    This paper presents the preliminary steps required for conducting experiments to obtain the optimal operating conditions of a hybrid impeller mixer and to determine the residence time distribution (RTD) using computational fluid dynamics (CFD). In this paper, impeller speed and clearance parameters are examined. The hybrid impeller mixer consists of a single Rushton turbine mounted above a single pitched blade turbine (PBT). Four impeller speeds, 50, 100, 150, and 200 rpm, and four impeller clearances, 25, 50, 75, and 100 mm, were the operation variables used in this study. CFD was utilized to initially screen the parameter ranges to reduce the number of actual experiments needed. Afterward, the residence time distribution (RTD) was determined using the respective parameters. Finally, the Fluent-predicted RTD and the experimentally measured RTD were compared. The CFD investigations revealed that an impeller speed of 50 rpm and an impeller clearance of 25 mm were not viable for experimental investigations and were thus eliminated from further analyses. The determination of RTD using a k-ε turbulence model was performed using CFD techniques. The multiple reference frame (MRF) was implemented and a steady state was initially achieved followed by a transient condition for RTD determination. PMID:25170524

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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...

  20. 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...

  1. 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.

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

    NASA Technical Reports Server (NTRS)

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

    1978-01-01

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

  3. 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.

  4. 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…

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

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

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

  6. 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…

  7. 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.

  8. 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.

  9. 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.

  10. 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

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

    NASA Astrophysics Data System (ADS)

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

    2013-01-01

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

  12. 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.

  13. 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.

  14. Projected noise in submillimeter-wave mixers with InSb Schottky diodes

    NASA Technical Reports Server (NTRS)

    Lieneweg, U.

    1980-01-01

    The reduction of the equivalent noise temperature in liquid-nitrogen-cooled submillimeter-wave mixers by the use of Schottky barriers on InSb instead of GaAs is evaluated by an analytical model that assumes limited local oscillator power and matched impedances. The calculations, executed at 1.0 and 1.8 THz, take plasma resonance and skin effect into account. For single and multiple contacts on homogeneous semiconductor materials of optimum doping, the noise of InSb diodes is smaller than that of GaAs diodes by a factor of 3 to 14. A simplified model is used to predict the performance of epitaxial structures as well as alternative materials.

  15. Solid lipid nanoparticles: continuous and potential large-scale nanoprecipitation production in static mixers.

    PubMed

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

    2012-06-01

    This work aimed at developing continuous and scalable nanoprecipitation synthesis of solid lipid nanoparticles (SLN) by mixing lipids acetonic solution with water using static mixers. The developed platform exhibited good control over the nanoprecipitation process and enabled the production of SLN below 200 nm at a throughput of 37.5-150 g/h (for 25 mg/ml lipid solution at a flow rate of 25-100 ml/min). Among the several process parameters investigated, the lipid concentration played primary role in influencing the size of the SLN and higher lipid concentration resulted in relatively larger particles. Fenofibrate, a model drug, has been successfully loaded into the SLN. Our work demonstrates the potential of applying static mixing-nanoprecipitation for continuous and large scale production of SLN. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. 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.

  17. 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.

  18. A novel approach to estimating the Doppler shift frequency from quadrature mixer output

    NASA Astrophysics Data System (ADS)

    Wang, M. Y.; Liu, A. D.; Zhou, C.; Hu, J. Q.; Li, H.; Lan, T.; Xie, J. L.; Ding, W. X.; Liu, W. D.; Yu, C. X.

    2017-07-01

    Doppler backscattering systems (DBSs) have been widely used in magnetic confinement fusion devices to measure the density fluctuations and propagation velocity of turbulence. However, the received signals of a DBS usually include both zero-order reflection and backscattering components, which results in interference in calculating the Doppler shift frequency from the backscattering components. A novel method is introduced here for estimating the Doppler shift frequency by separating the zero-order reflection and backscattering components using the cross-phase spectrum between the I-signal and Q-signal from a quadrature mixer, based on the difference in symmetrical characteristics between the zero-order reflection and backscattering signal spectra. It is proven that this method is more effective than traditional approaches, such as multiple signal classification and fast Fourier transformation, for extracting Doppler shift information.

  19. 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.

  20. 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.

  1. Application and mechanism of ultrasonic static mixer in heavy oil viscosity reduction.

    PubMed

    Shi, Chunwei; Yang, Wei; Chen, Jianbin; Sun, Xiaoping; Chen, Wenyi; An, Huiyong; Duo, Yili; Pei, Mingyuan

    2017-07-01

    In the present study, heavy oil viscosity reduction in Daqing oil field was investigated by using an ultrasonic static mixer. The influence of the ultrasonic power on the viscosity reduction rate was investigated and the optimal technological conditions were determined for the ultrasonic treatment. The mechanism for ultrasonic viscosity reduction was analyzed. The flow characteristics of heavy oil in the mixer under the effect of cavitation were investigated using numerical modeling, and energy consumptions were calculated during the ultrasonic treatment and vis-breaking processes. The experimental results indicated that the ultrasonic power made the largest impact on the viscosity reduction rate, followed by the reaction time and temperature. The highest viscosity reduction rate was 57.34%. Vacuole was migrated from the axis to the wall along the fluid, accelerating the two-phase transmission and enhancing the radial flow of the fluid, which significantly improved the ultrasonic viscosity reduction. Compared to the vis-breaking process, the energy consumption of ultrasonic treatment process was 43.03% lower when dealing with the same quality heavy oil. The optimal process conditions were found to be as follows: ultrasonic power of 1.8kW, reaction time of 45min and reaction temperature of 360°C. The dissociation of the molecules of heavy oil after ultrasonication has been checked. After being kept at room temperature 12days, some light components were produced by the cavitation cracking, so the viscosity of the residual oil could not return to that of the original residual oil, which meant that the "cage effect" was not reformed. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Modeling Cobble Transport in a Fluvial System for Provenance Studies: The Cement Mixer Experiment

    NASA Astrophysics Data System (ADS)

    Pound, K. S.; Heldberg, H.

    2016-12-01

    In order to model the rate at which cobbles of resistant rock are abraded during transport, a set of 17 cubes ( 13 cm edges) of igneous and metamorphic rock (granite, syenite, tonalite, gabbro, diorite, gneiss, schist) were placed in a cement mixer with a 248 liter (9 ft3) drum together with quartz sand and water ballast; 20-28 liters of water and 1-2 liters of quartz sand were used. The cement mixer was run in 1-hour increments, with the rocks traveling between 1.62 and 2.11 km/hr. The mass and volume of each `cube' as well as their long- intermediate- and short- axes were measured each hour. Fragmentation, rounding and other abrasion-related features were also recorded. The experiment was run in order to provide data that would assist in provenance studies in ancient conglomerates. The amount of rounding and the particle size is typically used as a proxy for distance travelled from source. Preliminary results show the cubes to be reduced to 35% - 80% of their original mass, and 36%-80% of their original volume after 7 hours (11.34 km - 14.74 km) of transport. In order to determine transport distances and rates in a gravel-bedded river, flow rates of 100 cm/sec - 350 cm/sec ( 3.28 - 11.48 ft/sec) are required to transport cobbles via saltation. Stream data from five Alaskan gravel-bedded rivers are used to approximate the likely transport distances associated with moderately- to well-rounded cobbles and pebbles.

  3. 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

  4. 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).

  5. 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).

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. Stability of a Quasi-Optical Superconducting NbTiN Hot-Electron Bolometer Mixer at 1.5 THz Frequency Band

    NASA Astrophysics Data System (ADS)

    Maezawa, H.; Yamakura, T.; Shiino, T.; Yamamoto, S.; Shiba, S.; Sakai, N.; Irimajiri, Y.; Jiang, L.; Nakai, N.; Seta, M.; Mizuno, A.; Nagahama, T.; Fukui, Y.

    2011-06-01

    We are developing quasi-optical superconducting hot-electron bolometer (HEB) mixer receivers for astronomical and atmospheric remote sensing applications. The microbridge of the HEB mixer was fabricated at room temperature from a 6.8-nm-thick niobium titanium nitride (NbTiN) film deposited on a 20-nm-thick aluminum nitride (AlN) buffer layer, using a helicon sputtering technique at a slow deposition rate. The mixer was cooled to 4.2 K using a closed-cycled mechanical 4 K pulse-tube cryocooler with a temperature fluctuation of ±1.6 mK. The stability of a large-volume NbTiN HEB mixer was studied at 1.47 THz by changing local oscillator (LO) power with the mixer bias voltage fixed. The intermediate frequency (IF) signal measured at 1.5 GHz had a maximum peak at a certain mixer bias current. The receiver noise temperature was lowest at around the IF maximum peak. It was also found that the IF signal was most stable at around the IF maximum peak under conditions in which the instability of LO pumping level, induced by small mechanical vibrations of the cryostat, remained in the optical system.

  14. 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.

  15. 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

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. New nano-matrix oral formulation of nanoprecipitated cyclosporine A prepared with multi-inlet vortex mixer.

    PubMed

    Suzuki, Hiroki; Hamao, Shun; Seto, Yoshiki; Sato, Hideyuki; Wong, Jennifer; Prud'homme, Robert K; Chan, Hak-Kim; Onoue, Satomi

    2017-01-10

    We present a combined nanoparticle (NP) formation process and spray drying to create a nano-matrix formulation of cyclosporine A (CsA) and mannitol (nCsA/MAN) to increase the bioavailability of CsA. CsA NPs were prepared by flash nano precipitation (FNP) using a multi-inlet vortex mixer, and spray-dried with or without mannitol to prepare nCsA/MAN or nanoprecipitated CsA powder (nCsA), respectively. Pre-forming the NPs by FNP uncouples the sizes of the CsA inclusions from the ultimate micron-sized powders produced by spray drying. Both CsA formulations were physicochemically characterized, and a pharmacokinetic study in rats was conducted after oral administration of CsA samples (10mg-CsA/kg). In the nCsA/MAN, CsA NPs dispersed in the mannitol matrix. In water, both the nCsA and nCsA/MAN reconstituted into NP form with average sizes of 317 and 298nm, respectively. In dissolution testing, nCsA and nCsA/MAN exhibited marked improvement in the dissolution with 31- and 41-fold higher drug release at 60min, compared with amorphous CsA, suggesting the significant impact of CsA NP size on dissolution. The higher dissolution rate with the mannitol matrix indicates the role of mannitol on wetting and dispersing the NP aggregates. Both nCsA formulations provided enhancement in CsA exposure in rats with a ca. 3-fold increase of the oral bioavailability compared with amorphous CsA. The nCsA/MAN showed faster absorption in vivo than nCsA, possibly due to the improved dissolution rate. From these findings, the nano-matrix formulation appears to be an efficacious oral dosage form to enhance the biopharmaceutical properties of CsA. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. 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

  5. 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.

  6. 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.

  7. Black tea assisted exfoliation using a kitchen mixer allowing one-step production of graphene

    NASA Astrophysics Data System (ADS)

    Ismail, Zulhelmi; Farhana Abu Kassim, Nurul; Hannifa Abdullah, Abu; Sakinah Zainal Abidin, Anis; Sameha Ismail, Fadwa; Yusoh, Kamal

    2017-07-01

    A kitchen mixer is one of the possible tools for the exfoliation of graphene. While organic solvents such as NMP or DMF are suitable for the exfoliation of graphite, the majority are toxic and dangerously harmful when exposed to humans and the environment. Therefore, an alternative solvent must be proposed for green and sustainable production of graphene. In this initial work, we have developed a new synthesis method for graphene through the direct exfoliation of graphite in commercial black tea. We found that our maximum yield concentration of graphene is Y  =  0.032 mg ml-l after 15 min of mixing. From the data of Raman, the level of defects in our produced graphene is suggested as being very minor (I D/I G  =  0.17), despite possible graphene functionalization by oxygen groups in tea. Incorporation of our graphene into PMMA results in shifting the onset temperature from 300 °C to 326 °C, which impressively validates the potential of the produced graphene as a thermal reinforcement material for polymer composites.

  8. 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.

  9. 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.

  10. A comparative study of ground tire rubber devulcanization using twin screw extruder and internal mixer

    NASA Astrophysics Data System (ADS)

    Ujianto, O.; Putri, D. B.; Jayatin; AWinarto, D.

    2017-07-01

    Devulcanization of ground tire rubber (GTR) was done using twin screw extruder (TSE) and internal mixer (IM). Processing parameters were varied to analyze its effect on gel content. Fourier Transform Infrared Spectroscopy (FTIR) analysis was performed as qualitative technique to confirm structural change. The devulcanized rubbers with the least gel content percentage produced in both TSE and IM were then used as filler in natural rubber (NR)/coconut coir (CC) composite preparation. Effects of gel content percentage on NR/CC composite tensile strength and elongation at break were analyzed. The results show that the gel content decreased by 41% for sample processed in TSE and 50% in IM compared to control sample. Overall, the devulcanization is influenced by high energy generated by thermal or thermo-mechanical process. FTIR spectra show chemically structural changes of GTR as C=C, CH2, CH3 with higher intensity for IM sample than its counterpart indicated devulcanization. The replacement of GTR to DGTR on NR/CC/GTR composites provided less network structures and resulted better tensile strength and elongation at break.

  11. 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.

  12. Application of graphene from exfoliation in kitchen mixer allows mechanical reinforcement of PVA/graphene film

    NASA Astrophysics Data System (ADS)

    Ismail, Zulhelmi; Abdullah, Abu Hannifa; Zainal Abidin, Anis Sakinah; Yusoh, Kamal

    2017-08-01

    Mechanical properties of polyvinyl alcohol (PVA) can be reinforced from the addition of graphene into its matrix. However, pristine graphene lacks solubility in water and thus makes dispersion a challenging task. Notably, functionalisation of graphene is required to accommodate graphene presence in the water. In this work, we have used a kitchen mixer to produce gum Arabic-graphene (GGA) for the first time as filler for mechanical reinforcement of PVA. For the characterisation of exfoliated graphene, mean lateral size of GGA was measured from the imaging by transmission electron microscopy while the mean thickness of graphene was predicted from the obtained spectra by Raman spectroscopy. During the preparation of PVA/graphene film by solution casting, GGA was varied between 0, 0.05, 0.075, 0.10 and 0.15 wt% in concentration. We found that the presence of GGA in PVA improves the tensile stress and elastic modulus about 72-200 and 19-187% from the original values. The data from Halpin-Tsai meanwhile suggested that the mechanical reinforcement of PVA/graphene film is due to the random distribution network of GGA in PVA.

  13. 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. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Liquid propellant thermal conditioning system test program

    NASA Technical Reports Server (NTRS)

    Bullard, B. R.

    1972-01-01

    Results are presented from more than 1500 hours of testing on a liquid hydrogen thermal conditioning unit. Test parameters included: mixer and vent flow rates; tank size; ullage volume; pressurant gas; pressurant temperature; pressure level; and heat rate. Gaseous hydrogen and helium were used as pressurants. Analytical models were developed to correlate the test data and relate the performance to that anticipated in zero gravity. Experimental and theoretical results are presented which relate the variables controlling vapor condensation at a moving interface.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. Fabrication of Functionalized Double-Lamellar Multifunctional Envelope-Type Nanodevices Using a Microfluidic Chip with a Chaotic Mixer Array

    PubMed Central

    Kitazoe, Katsuma; Park, Yeon-Su; Kaji, Noritada; Okamoto, Yukihiro; Tokeshi, Manabu; Kogure, Kentaro; Harashima, Hideyoshi; Baba, Yoshinobu

    2012-01-01

    Multifunctional envelope-type nanodevices (MENDs) are very promising non-viral gene delivery vectors because they are biocompatible and enable programmed packaging of various functional elements into an individual nanostructured liposome. Conventionally MENDs have been fabricated by complicated, labor-intensive, time-consuming bulk batch methods. To avoid these problems in MEND fabrication, we adopted a microfluidic chip with a chaotic mixer array on the floor of its reaction channel. The array was composed of 69 cycles of the staggered chaotic mixer with bas-relief structures. Although the reaction channel had very large Péclet numbers (>105) favorable for laminar flows, its chaotic mixer array led to very small mixing lengths (<1.5 cm) and that allowed homogeneous mixing of MEND precursors in a short time. Using the microfluidic chip, we fabricated a double-lamellar MEND (D-MEND) composed of a condensed plasmid DNA core and a lipid bilayer membrane envelope as well as the D-MEND modified with trans-membrane peptide octaarginine. Our lab-on-a-chip approach was much simpler, faster, and more convenient for fabricating the MENDs, as compared with the conventional bulk batch approaches. Further, the physical properties of the on-chip-fabricated MENDs were comparable to or better than those of the bulk batch-fabricated MENDs. Our fabrication strategy using microfluidic chips with short mixing length reaction channels may provide practical ways for constructing more elegant liposome-based non-viral vectors that can effectively penetrate all membranes in cells and lead to high gene transfection efficiency. PMID:22723929

  20. Fabrication of functionalized double-lamellar multifunctional envelope-type nanodevices using a microfluidic chip with a chaotic mixer array.

    PubMed

    Kitazoe, Katsuma; Park, Yeon-Su; Kaji, Noritada; Okamoto, Yukihiro; Tokeshi, Manabu; Kogure, Kentaro; Harashima, Hideyoshi; Baba, Yoshinobu

    2012-01-01

    Multifunctional envelope-type nanodevices (MENDs) are very promising non-viral gene delivery vectors because they are biocompatible and enable programmed packaging of various functional elements into an individual nanostructured liposome. Conventionally MENDs have been fabricated by complicated, labor-intensive, time-consuming bulk batch methods. To avoid these problems in MEND fabrication, we adopted a microfluidic chip with a chaotic mixer array on the floor of its reaction channel. The array was composed of 69 cycles of the staggered chaotic mixer with bas-relief structures. Although the reaction channel had very large Péclet numbers (>10(5)) favorable for laminar flows, its chaotic mixer array led to very small mixing lengths (<1.5 cm) and that allowed homogeneous mixing of MEND precursors in a short time. Using the microfluidic chip, we fabricated a double-lamellar MEND (D-MEND) composed of a condensed plasmid DNA core and a lipid bilayer membrane envelope as well as the D-MEND modified with trans-membrane peptide octaarginine. Our lab-on-a-chip approach was much simpler, faster, and more convenient for fabricating the MENDs, as compared with the conventional bulk batch approaches. Further, the physical properties of the on-chip-fabricated MENDs were comparable to or better than those of the bulk batch-fabricated MENDs. Our fabrication strategy using microfluidic chips with short mixing length reaction channels may provide practical ways for constructing more elegant liposome-based non-viral vectors that can effectively penetrate all membranes in cells and lead to high gene transfection efficiency.