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Sample records for ratio pyrometer system

  1. Design, Fabrication and Testing of an Infrared Ratio Pyrometer System for the Measurement of Gasifier Reaction Chamber Temperature

    SciTech Connect

    Tom Leininger

    2005-03-31

    Texaco was awarded contract DE-FC26-99FT40684 from the U.S. DOE to design, build, bench test and field test an infrared ratio pyrometer system for measuring gasifier temperature. The award occurred in two phases. Phase 1, which involved designing, building and bench testing, was completed in September 2000, and the Phase 1 report was issued in March 2001. Phase 2 was completed in 2005, and the results of the field test are contained in this final report. Two test campaigns were made. In the first one, the pyrometer was sighted into the gasifier. It performed well for a brief period of time and then experienced difficulties in keeping the sight tube open due to a slag accumulation which developed around the opening of the sight tube in the gasifier wall. In the second test campaign, the pyrometer was sighted into the top of the radiant syngas cooler through an unused soot blower lance. The pyrometer experienced no more problems with slag occlusions, and the readings were continuous and consistent. However, the pyrometer readings were 800 to 900 F lower than the gasifier thermocouple readings, which is consistent with computer simulations of the temperature distribution inside the radiant syngas cooler. In addition, the pyrometer readings were too sluggish to use for control purposes. Additional funds beyond what were available in this contract would be required to develop a solution that would allow the pyrometer to be used to measure the temperature inside the gasifier.

  2. Pyrometer

    NASA Technical Reports Server (NTRS)

    Quince, Asia N. (Inventor); Stein, Alexander (Inventor)

    2015-01-01

    A non-contact pyrometer and method for calibrating the same are provided. The pyrometer includes a radiation sensor configured to measure at least a portion of a radiance signal emitted from a target medium and output a voltage that is a function of an average of the absorbed radiance signal, and an optical window disposed proximate the radiation sensor and configured to control a wavelength range of the radiance signal that reaches the radiation sensor. The pyrometer may further include a reflective enclosure configured to receive the target medium therein, wherein the radiation sensor and the optical window are disposed within the reflective enclosure, an amplifier in communication with an output of the radiation sensor, and a data acquisition system in communication with an output of the amplifier.

  3. DESIGN, FABRICATION, ASSEMBLY AND BENCH TESTING OF A TEXACO INFRARED RATIO PYROMETER SYSTEM FOR THE MEASUREMENT OF REACTION CHAMBER TEMPERATURE

    SciTech Connect

    Tom Leininger

    2001-03-31

    Reliable measurement of gasifier reaction chamber temperature is important for the proper operation of slagging, entrained-flow gasification processes. Historically, thermocouples have been used as the main measurement technique, with the temperature inferred from syngas methane concentration being used as a backup measurement. While these have been sufficient for plant operation in many cases, both techniques suffer from limitations. The response time of methane measurements is too slow to detect rapid upset conditions, and thermocouples are subject to long-term drift, as well as slag attack, which eventually leads to failure of the thermocouple. Texaco's Montebello Technology Center (MTC) has developed an infrared ratio pyrometer system for measuring gasifier reaction chamber temperature. This system has a faster response time than both methane and thermocouples, and has been demonstrated to provide reliable temperature measurements for longer periods of time when compared to thermocouples installed in the same MTC gasifier. In addition, the system can be applied to commercial gasifiers without any significant scale-up issues. The major equipment items, the purge system, and the safety shutdown system in a commercial plant are essentially identical to the prototypes at MTC. The desired result of this DOE program is ''a bench-scale prototype, either assembled or with critical components (laboratory) tested in a convincing manner.'' The prototype of the pyrometer system (including gasifier optical access port) that was designed, assembled and tested for this program, has had previous prototypes that have been built and successfully tested under actual coal and coke gasification conditions in three pilot units at MTC. It was the intent of the work performed under the auspices of this program to review and update the existing design, and to fabricate and bench test an updated system that can be field tested in one or more commercial gasifiers during a follow on phase of this program. For all intents and purposes, the development, bench testing and pilot unit testing of this temperature measurement system has already been done, and was mostly a matter of getting the hardware ready for a commercial field test. The benefits of field-testing are (1) Texaco will gain long-term commercial operating experience and (2) commercial gasifier operators will gain confidence that this system can perform reliably under true commercial plant conditions. This work was performed by Texaco at its Montebello Technology Center in South El Monte, California.

  4. Automated coke guide pyrometer system

    SciTech Connect

    Horvath, V.V.; Pfeiffer, T.J.; Wetzel, J.S.

    1985-09-01

    Coke temperature in coke ovens during pushing is monitored automatically by a computer based system using five pyrometers. Vertical and horizontal temperature profiles of the oven walls and entire coke battery are used to pinpoint heating problems, adjust heating practices for maximum efficiency and set priorities for battery maintenance.

  5. High resolution color band pyrometer ratioing

    NASA Technical Reports Server (NTRS)

    Bickler, Donald B. (Inventor); Henry, Paul K. (Inventor); LoGiurato, D. Daniel (Inventor)

    1989-01-01

    The sensing head of a two-color band ratioing pyrometer of a known type using a fiber optic cable to couple radiation to dual detector photodiodes is improved to have high spatial resolution by focusing the radiation received through an objective lens (i.e., by focusing the image of a target area) onto an opaque sheet spaced in front of the input end of the fiber optic cable. A two-mil hole in that sheet then passes radiation to the input end of the cable. The detector has two channels, one for each color band, with an electronic-chopper stabilized current amplifier as the input stage followed by an electronic-chopper stabilized voltage amplifier.

  6. PYROLASER - PYROLASER OPTICAL PYROMETER OPERATING SYSTEM

    NASA Technical Reports Server (NTRS)

    Roberts, F. E.

    1994-01-01

    The PYROLASER package is an operating system for the Pyrometer Instrument Company's Pyrolaser. There are 6 individual programs in the PYROLASER package: two main programs, two lower level subprograms, and two programs which, although independent, function predominantly as macros. The package provides a quick and easy way to setup, control, and program a standard Pyrolaser. Temperature and emissivity measurements may be either collected as if the Pyrolaser were in the manual operations mode, or displayed on real time strip charts and stored in standard spreadsheet format for post-test analysis. A shell is supplied to allow macros, which are test-specific, to be easily added to the system. The Pyrolaser Simple Operation program provides full on-screen remote operation capabilities, thus allowing the user to operate the Pyrolaser from the computer just as it would be operated manually. The Pyrolaser Simple Operation program also allows the use of "quick starts". Quick starts provide an easy way to permit routines to be used as setup macros for specific applications or tests. The specific procedures required for a test may be ordered in a sequence structure and then the sequence structure can be started with a simple button in the cluster structure provided. One quick start macro is provided for continuous Pyrolaser operation. A subprogram, Display Continuous Pyr Data, is used to display and store the resulting data output. Using this macro, the system is set up for continuous operation and the subprogram is called to display the data in real time on strip charts. The data is simultaneously stored in a spreadsheet format. The resulting spreadsheet file can be opened in any one of a number of commercially available spreadsheet programs. The Read Continuous Pyrometer program is provided as a continuously run subprogram for incorporation of the Pyrolaser software into a process control or feedback control scheme in a multi-component system. The program requires the Pyrolaser to be set up using the Pyrometer String Transfer macro. It requires no inputs and provides temperature and emissivity as outputs. The Read Continuous Pyrometer program can be run continuously and the data can be sampled as often or as seldom as updates of temperature and emissivity are required. PYROLASER is written using the Labview software for use on Macintosh series computers running System 6.0.3 or later, Sun Sparc series computers running OpenWindows 3.0 or MIT's X Window System (X11R4 or X11R5), and IBM PC or compatibles running Microsoft Windows 3.1 or later. Labview requires a minimum of 5Mb of RAM on a Macintosh, 24Mb of RAM on a Sun, and 8Mb of RAM on an IBM PC or compatible. The Labview software is a product of National Instruments (Austin,TX; 800-433-3488), and is not included with this program. The standard distribution medium for PYROLASER is a 3.5 inch 800K Macintosh format diskette. It is also available on a 3.5 inch 720K MS-DOS format diskette, a 3.5 inch diskette in UNIX tar format, and a .25 inch streaming magnetic tape cartridge in UNIX tar format. An electronic copy of the documentation in Macintosh WordPerfect version 2.0.4 format is included on the distribution medium. Printed documentation is included in the price of the program. PYROLASER was developed in 1992.

  7. Coke guide pyrometer: a system for coke temperature measurement

    SciTech Connect

    Lynn, J.B.; Kisner, G.E.

    1982-01-01

    A coke guide pyrometer system is described which measures the surface temperature of the coke mass as it is pushed from the oven. Five sensors are mounted at various heights in the same vertical plane on one side of the coke guide. Fiber optic cables transmit the infrared radiation picked up by these sensors to infrared photocells which convert the radiation to electrical signals that are transmitted to a data processor. The computer produces graphs showing the temperature distribution in the coke oven vertically and horizontally and along the length of the battery from oven to oven. Isothermal contour profiles can be generated from the data. Using the data, heating imbalances can be corrected, malfunctioning flues can be located, and coke heights can be monitored to detect lost productivity due to underfilling. The system has been operating for a year on a 6 meter battery at Bethelem Steel Corporation. Graphs and isotherms are presented to show the usefulness of the data. (CKK)

  8. Development of a Multi-Point Pyrometer System (MPPS) for measuring surface temperature and emissivity

    SciTech Connect

    Benton, R.D.; Jang, Ping-Rey

    1993-06-01

    In support of the US DOE MHD research program, the Diagnostic Instrumentation and Analysis Laboratory (DIAL) has been actively engaged in developing and applying advanced optical diagnostic techniques and instrumentation systems to high temperature coal-fired gas streams for over a decade. One of the earliest diagnostic systems developed by DIAL was a two color pyrometer (TCP). In this system, two commercial single-color pyrometers and a microprocessor system were used to form a TCP which can make accurate measurements of surfaces of unknown emissivity and temperature. This system has been used extensively to make measurements in support of the national MHD program. This report describes this system.

  9. Study of the Performance of a Streaked Optical Pyrometer System for Temperature Measurement of Shocked Materials

    NASA Astrophysics Data System (ADS)

    Zhang, Chen; Liu, Hao; Wang, Zhebin; Jiang, Xiaohua; Zhang, Huige; Liu, Yonggang; Li, Zhichao; Li, Sanwei; Yang, Dong; Ding, Yongkun; Zhao, Bin; Hu, Guangyue; Zheng, Jian

    2014-06-01

    A streaked optical pyrometer (SOP) is developed and calibrated for the measurement of the temperature of shocked materials. In order to achieve a higher relative sensitivity, a one-channel scheme is adopted for the system. The system is calibrated with a shocked step-shaped aluminum sample in the SG-III prototype laser facility. The relation between the count number in the detection system and the sample temperature is thus obtained, which can be adopted to infer the temperature of any shocked materials in future experiments.

  10. Streaked Optical Pyrometer System for Laser-Driven Shock-Wave Experiments on OMEGA

    SciTech Connect

    Miller, J.E.; Boehly, T.R.; Melchior, Meyerhofer, D.D.; Celliers, P.M.; Eggert, J.H.; Hicks, D.G.; Sorce, C.M.; Oertel, J.A.; Emmel, P.M.

    2007-03-23

    The temperature of laser-driven shock waves is of interest to inertial confinement fusion and high-energy-density physics. We report on a streaked optical pyrometer that measures the self-emission of laser-driven shocks simultaneously with a velocity interferometer system for any reflector (VISAR). Together these diagnostics are used to obtain the temporally and spatially resolved temperatures of ~Mbar shocks driven by the OMEGA laser. We provide a brief description of the diagnostic and how it is used with VISAR. Key spectral calibration results are discussed and important characteristics of the recording system are presented.

  11. Upgrades to the VISAR-streaked optical pyrometer (SOP) system on NIF

    NASA Astrophysics Data System (ADS)

    Manuel, A. M.; Millot, M.; Seppala, L. G.; Frieders, G.; Zeid, Z.; Christensen, K.; Celliers, P. M.

    2015-08-01

    The Velocity Interferometer System for Any Reflector (VISAR) is a critical diagnostic in Inertial Confinement Fusion and High Energy Density research as it has the ability to track shock fronts or interfaces moving 0.1-100 km/s with great accuracy. At the National Ignition Facility (NIF), the VISAR has recently been used successfully for implosion tuning and equation of state measurements. However, the initial design of the companion Streaked Optical Pyrometer (SOP) to measure spectral radiance - hence shock temperature - suffers from large background levels and poor spatial resolution. We report on an upgrade to improve the spatial resolution in the 560-640nm band by using custom lenses and replacing the Dove prism with a K-mirror and implementing a gating-circuit for the streak camera to reduce background signal. We envision that upgraded SOP will provide high quality data collection matching NIF VISAR's standards.

  12. Improvements to the three-color optical CCD-based pyrometer system

    SciTech Connect

    Fu Tairan; Zhao Huan; Zeng Jun; Wang Zhe; Zhong Maohua; Shi Congling

    2010-11-01

    We put forward an improved three-color measurement scheme with a color CCD sensor using the combination of effective wavelengths and blackbody calibrations. The process of effective wavelengths realizes the separation of the emissivity function from the measurement integral equation. This improved method not only effectively avoids errors arising from the traditional process adopting the basic wavelengths, but also simplifies the complex integral calculations. For a blackbody or graybody, the measurement performance of the pyrometer was experimentally investigated from the point of the temperature sensitivity. The results show that narrowing the spectrum bandwidth with different bandpass spectral filters may improve the temperature sensitivities. The spectrum adjustment not only makes the linear emissivity more suitable in the narrower waveband, but also reduces the numerical uncertainty of the effective wavelengths. For nongray objects, the effects of the numerical uncertainty of the effective wavelengths to measurements were quantificationally evaluated at different measurement conditions (different temperatures, emissivities, and spectrums). The results indicate that the reference values of 584, 555, and 511nm or 607, 560, and 506nm of the effective wavelengths are reasonable for the present system with the modified spectral response using Filter 1 or Filter 2. The maximum calculation errors arising from the reference effective wavelengths are less than 1.6%. In this paper, the technical realization steps of the improved method are also described. The measurement experiments of a metal sample in hot environments were carried out to further verify the applicability of this improved CCD-based pyrometer. The results agreed well with the spectrometer-based results.

  13. Closed loop control for laser micro spot welding using fast pyrometer systems

    NASA Astrophysics Data System (ADS)

    Stehr, T.; Hermsdorf, J.; Henning, T.; Kling, R.

    Laser micro spot welding offers temperature resistant high strength contacts without filler material. However, due to varying surface absorption properties of copper, the welding quality shows poor reproducibility. To stabilize the process we set up a power control for laser micro spot welding of copper. It consists of a high speed pyrometer and an external micro controller. The subject of the investigations is to apply a constant energy amount using conduction welding to increase the process stability. Using the closed loop control, the standard deviation of pull force for overlap welds is reduced from 3.3N to 1.3N.

  14. The use of optical pyrometers in axial flow turbines

    NASA Astrophysics Data System (ADS)

    Sellers, R. R.; Przirembel, H. R.; Clevenger, D. H.; Lang, J. L.

    1989-07-01

    An optical pyrometer system that can be used to measure metal temperatures over an extended range of temperature has been developed. Real-time flame discrimination permits accurate operation in the gas turbine environment with high flame content. This versatile capability has been used in a number of ways. In experimental engines, a fixed angle pyrometer has been used for turbine health monitoring for the automatic test stand abort system. Turbine blade creep capability has been improved by tailoring the burner profile based on measured blade temperatures. Fixed and traversing pyrometers were used extensively during engine development to map blade surface temperatures in order to assess cooling effectiveness and identify optimum configurations. Portable units have been used in turbine field inspections. A new low temperature pyrometer is being used as a diagnostic tool in the alternate turbopump design for the Space Shuttle main engine. Advanced engine designs will incorporate pyrometers in the engine control system to limit operation to safe temperatures.

  15. Measurement of turbine blade temperature using pyrometer

    NASA Astrophysics Data System (ADS)

    Cheng, H.; Du, C.

    1985-09-01

    This paper presents the study of application of a self-made turbine blade pyrometer to measuring rotating turbine blade temperatures in a bed testing aeroengine. The study includes the temperature measuring principle and the pyrometer system; installation and adjustment of the double ball-floating type configuration optical head which goes through four different high temperatures bulkheads; and measurement of three kinds of temperature (the average blade temperature Ta, the average peak blade temperature Tap, and the maximum peak blade temperature Tmp) for all rotor blades of the turbine first stage. The experimental data analysis reveals that the first attempt of application of this pyrometer is successful. The measurement errors in the temperature range of 550-1200 C are within + or - 1 percent of calculated blade temperatures.

  16. A multicolor imaging pyrometer

    NASA Technical Reports Server (NTRS)

    Frish, Michael B.; Frank, Jonathan H.

    1989-01-01

    A multicolor imaging pyrometer was designed for accurately and precisely measuring the temperature distribution histories of small moving samples. The device projects six different color images of the sample onto a single charge coupled device array that provides an RS-170 video signal to a computerized frame grabber. The computer automatically selects which one of the six images provides useful data, and converts that information to a temperature map. By measuring the temperature of molten aluminum heated in a kiln, a breadboard version of the device was shown to provide high accuracy in difficult measurement situations. It is expected that this pyrometer will ultimately find application in measuring the temperature of materials undergoing radiant heating in a microgravity acoustic levitation furnace.

  17. C2 Swan spectrum used as a molecular pyrometer in transferred arc and the influence noise to signal ratio on the temperature values

    NASA Astrophysics Data System (ADS)

    Nassar, H.

    2014-05-01

    The C2 Swan system molecular emission spectrum is frequently observed in arc plasmas containing hydrocarbons. The spectra emitted from 5 kw in the transferred arc reactor at atmospheric pressure by CH4/CO2/Ar mixture are recorded with the help of an optical system consisting of a linear CCD array coupled with 2m spectrometer. The rotational temperature of 4300300K is found from the experimental Abel inverted spectra in the arc center after a point-to-point comparison of the spectrum with a computer simulated one. The influence of the noise to signal ratio has been studied, if the noise to signal ratio is about 10% we found an error of 7% at temperature 3000K and 10% at 6000K.

  18. Scanning optical pyrometer for measuring temperatures in hollow cathodes

    SciTech Connect

    Polk, J. E.; Marrese-Reading, C. M.; Thornber, B.; Dang, L.; Johnson, L. K.; Katz, I.

    2007-09-15

    Life-limiting processes in hollow cathodes are determined largely by the temperature of the electron emitter. To support cathode life assessment, a noncontact temperature measurement technique which employs a stepper motor-driven fiber optic probe was developed. The probe is driven inside the hollow cathode and collects light radiated by the hot interior surface of the emitter. Ratio pyrometry is used to determine the axial temperature profile. Thermocouples on the orifice plate provide measurements of the external temperature during cathode operation and are used to calibrate the pyrometer system in situ with a small oven enclosing the externally heated cathode. The diagnostic method and initial measurements of the temperature distribution in a hollow cathode are discussed.

  19. Active millimeter-wave pyrometer

    SciTech Connect

    Woskov, P.P.

    1995-04-01

    There is a continuing need for reliable and accurate temperature measurements inside hot and dirty environments. Many processes encompassing manufacturing, waste remediation, and power production make use of high temperature furnaces where currently available temperature measurement instrumentation is not always adequate. Thermocouples require direct surface contact and are limited to temperatures < 1700{degrees}C. Infrared pyrometers require clear, direct lines of sight that are frequently unavailable or become obscured during operations. Furthermore the surface emissivity, which can vary during the process, must be known. Millimeter-wave pyrometry overcomes all these limitations. A 135 GHz heterodyne receiver with a rotatable graphite waveguide/mirror system has been implemented on a waste remediation DC arc furnace for internal surface temperature measurements. The linear temperature measurement range extends from <1{degrees} to approximately 15,000{degrees}C relative to ambient with a simultaneous capability to monitor surface reflectivity with the local oscillator leakage. Reliable and robust operation on a continuous 24 hour basis in a smoky, dirty furnace environment is demonstrated for more than 5 furnace runs reaching a maximum temperature of 2200{degrees}C. Complete temperature profile measurements with approximately 5 cm spatial resolution clearly documented thermal gradients on the slag melt surface and refractory walls and ceiling for all operating regimes of the furnace. The unique active probing capability of this instrument provided additional real time information on melt surface turbulence, changing furnace wall emissivity, and millimeter-wave optic losses inside the furnace.

  20. Multicolor pyrometer for materials processing in space

    NASA Technical Reports Server (NTRS)

    Frish, M. B.; Frank, J.; Baker, J. E.; Foutter, R. R.; Beerman, H.; Allen, M. G.

    1990-01-01

    This report documents the work performed by Physical Sciences Inc. (PSI), under contract to NASA JPL, during a 2.5-year SBIR Phase 2 Program. The program goals were to design, construct, and program a prototype passive imaging pyrometer capable of measuring, as accurately as possible, and controlling the temperature distribution across the surface of a moving object suspended in space. These goals were achieved and the instrument was delivered to JPL in November 1989. The pyrometer utilizes an optical system which operates at short wavelengths compared to the peak of the black-body spectrum for the temperature range of interest, thus minimizing errors associated with a lack of knowledge about the heated sample's emissivity. To cover temperatures from 900 to 2500 K, six wavelengths are available. The preferred wavelength for measurement of a particular temperature decreases as the temperature increases. Images at all six wavelengths are projected onto a single CCD camera concurrently. The camera and optical system have been calibrated to relate the measured intensity at each pixel to the temperature of the heated object. The output of the camera is digitized by a frame grabber installed in a personal computer and analyzed automatically to yield temperature information. The data can be used in a feedback loop to alter the status of computer-activated switches and thereby control a heating system.

  1. Laser Pyrometer For Spot Temperature Measurements

    NASA Technical Reports Server (NTRS)

    Elleman, D. D.; Allen, J. L.; Lee, M. C.

    1988-01-01

    Laser pyrometer makes temperature map by scanning measuring spot across target. Scanning laser pyrometer passively measures radiation emitted by scanned spot on target and calibrated by similar passive measurement on blackbody of known temperature. Laser beam turned on for active measurements of reflectances of target spot and reflectance standard. From measurements, temperature of target spot inferred. Pyrometer useful for non-contact measurement of temperature distributions in processing of materials.

  2. IR optical fiber-based noncontact pyrometer for drop tube instrumentation

    NASA Technical Reports Server (NTRS)

    May, R. G.; Moneyhun, S.; Saleh, W.; Sudeora, S.; Claus, R. O.; Buoncristiani, A. M.

    1989-01-01

    The design of a two color pyrometer with infrared optical fiber bundles for collection of the infrared radiation is described. The pyrometer design is engineered to facilitate its use for measurement of the temperature of small, falling samples in a microgravity materials processing experiment using a 100 meter long drop tube. Because the samples are small and move rapidly through the field of view of the pyrometer, the optical power budget of the detection system is severly limited. Strategies for overcoming this limitation are discussed.

  3. Uncertainty of Pyrometers in a Casting Facility

    SciTech Connect

    Mee, D.K.; Elkins, J.E.; Fleenor, R.M.; Morrision, J.M.; Sherrill, M.W.; Seiber, L.E.

    2001-12-07

    This work has established uncertainty limits for the EUO filament pyrometers, digital pyrometers, two-color automatic pyrometers, and the standards used to certify these instruments (Table 1). If symmetrical limits are used, filament pyrometers calibrated in Production have certification uncertainties of not more than {+-}20.5 C traceable to NIST over the certification period. Uncertainties of these pyrometers were roughly {+-}14.7 C before introduction of the working standard that allowed certification in the field. Digital pyrometers addressed in this report have symmetrical uncertainties of not more than {+-}12.7 C or {+-}18.1 C when certified on a Y-12 Standards Laboratory strip lamp or in a production area tube furnace, respectively. Uncertainty estimates for automatic two-color pyrometers certified in Production are {+-}16.7 C. Additional uncertainty and bias are introduced when measuring production melt temperatures. A -19.4 C bias was measured in a large 1987 data set which is believed to be caused primarily by use of Pyrex{trademark} windows (not present in current configuration) and window fogging. Large variability (2{sigma} = 28.6 C) exists in the first 10 m of the hold period. This variability is attributed to emissivity variation across the melt and reflection from hot surfaces. For runs with hold periods extending to 20 m, the uncertainty approaches the calibration uncertainty of the pyrometers. When certifying pyrometers on a strip lamp at the Y-12 Standards Laboratory, it is important to limit ambient temperature variation (23{+-}4 C), to order calibration points from high to low temperatures, to allow 6 m for the lamp to reach thermal equilibrium (12 m for certifications below 1200 C) to minimize pyrometer bias, and to calibrate the pyrometer if error exceeds vendor specifications. A procedure has been written to assure conformance.

  4. A Self Calibrating Emissivity and/or Transmissivity Independent Multiwavelength Pyrometer

    NASA Technical Reports Server (NTRS)

    Ng, Daniel

    1996-01-01

    Pyrometer is a favorite method to do remote temperature measurement in research and development. One-color, two-color and the disappearing filament pyrometers are most common, multicolor and multiwavelength pyrometers are being introduced recently. All these pyrometers invariably require, in one form or another, information concerning emissivity, the medium transmissivity, their ratio at some two spectral regions, the instrument's calibration constant, etc. for their operation. This information can come from hand books, from the manufacturer or in some instances, from results of dedicated separate experiments. Often this information is sample or instrument specific. Sometimes this information, though obtained from a special experiment, is obtained using a separate sample rather than the one pursued for temperature measurement. Then, there would be the question of variability from sample to sample and variability from batch to batch in the sample used. Also, previously determined calibrations can change with time, and the only way to reduce uncertainty is to perform the calibration more frequently or even immediately before the experiment. We have developed a multiwavelength pyrometer, which eliminates the need to supply the necessary emissivity and/or transmissivity information and the instrument calibration constants ahead of time. The pyrometer calibrates itself from its first cycle data.

  5. Multi-band pyrometer uncertainty analysis and improvement

    NASA Astrophysics Data System (ADS)

    Yang, Yongjun; Zhang, Xuecong; Cai, Jing; Wang, Zhongyu

    2010-12-01

    According to the energy ratio value of multi-band radiating from the measured surface, the 'true' temperature can be calculated by multi-band pyrometer. Multi-band pyrometer has many advantages: it can hardly be affected by the emission of measured surface and the environment radiation, and it has higher Signal-to-Noise Ratio and higher temperature measurement accuracy. This paper introduces the principle of a multi-band pyrometer and the uncertainty of measurement result is evaluated by using Monte-Carlo Method (MCM). The result shows that the accuracy of effective wavelength is the largest source of uncertainty and the other main source is reference temperature. When using ordinary blackbody furnace with continuous temperature, which can provide reference temperature and calibrate effective wavelength, the uncertainty component is 2.17K and 2.48K respectively. The combined standard uncertainty is 3.30K. A new calibration method is introduced. The effective wavelength is calibrated by monochromator, and the reference temperature is provided by fixed point black body furnace. The uncertainty component is decreased to 0.73K and 0.12K respectively. The measurement uncertainty is decreased to 0.74K. The temperature measurement accuracy is enhanced.

  6. Self-calibrated active pyrometer for furnace temperature measurements

    DOEpatents

    Woskov, Paul P.; Cohn, Daniel R.; Titus, Charles H.; Surma, Jeffrey E.

    1998-01-01

    Pyrometer with a probe beam superimposed on its field-of-view for furnace temperature measurements. The pyrometer includes a heterodyne millimeter/sub-millimeter-wave or microwave receiver including a millimeter/sub-millimeter-wave or microwave source for probing. The receiver is adapted to receive radiation from a surface whose temperature is to be measured. The radiation includes a surface emission portion and a surface reflection portion which includes the probe beam energy reflected from the surface. The surface emission portion is related to the surface temperature and the surface reflection portion is related to the emissivity of the surface. The simultaneous measurement of surface emissivity serves as a real time calibration of the temperature measurement. In an alternative embodiment, a translatable base plate and a visible laser beam allow slow mapping out of interference patterns and obtaining peak values therefor. The invention also includes a waveguide having a replaceable end portion, an insulating refractory sleeve and/or a source of inert gas flow. The pyrometer may be used in conjunction with a waveguide to form a system for temperature measurements in a furnace. The system may employ a chopper or alternatively, be constructed without a chopper. The system may also include an auxiliary reflector for surface emissivity measurements.

  7. Characteristic ratio assignment in fractional order systems.

    PubMed

    Tabatabaei, Mohammad; Haeri, Mohammad

    2010-10-01

    In this paper the characteristic ratios and generalized time constant are defined for all-pole commensurate fractional order systems. The sufficient condition for stability of these systems in terms of their characteristic ratios is obtained. Also an analytical approach for characteristic ratio assignment (CRA) to have a non-overshooting fast closed loop step response is introduced. The proposed CRA method is then employed to design a fractional order controller. Computer simulation results are presented to illustrate the performance of the CRA based designed fractional order controllers. PMID:20619834

  8. Development of three-wavelength CCD image pyrometer used for the temperature field measurements of continuous casting billets

    SciTech Connect

    Xie, Zhi; Bai, Haicheng

    2014-02-15

    This paper develops an imaging based three-color pyrometer for the monitoring of temperature distribution in a continuous casting billet. A novel optical device, together with an embedded electronic system, is designed to sequentially collect a dark image and three thermal images with specified wavelengths on a same monochromatic charge-coupled-device (CCD). The three thermal images provide the basis for the determination of target temperature, while the dark image is used to online eliminate the dark noise of CCD with a differential method. This image pyrometer is not only independent of target emissivity but also overcomes the dissimilarity of measuring accuracy between the micro-sensors of CCD resulted from the non-uniformity of pixels’ intensity response and the vignetting of optical system. Furthermore, a precise two-color temperature field measuring model on the CCD pyrometer is established, based on which a self-adaptive light-integration mechanism is presented. Compared with the traditional fixed light-integration method, the measuring range of the pyrometer is greatly extended and its sensitivity in low temperature segment is improved. The test results in a steel factory demonstrate that the pyrometer is capable of meeting the requirement of surface temperature measurements about casting billets. Reliability and accuracy of measurement results are also discussed herein.

  9. Development of three-wavelength CCD image pyrometer used for the temperature field measurements of continuous casting billets.

    PubMed

    Xie, Zhi; Bai, Haicheng

    2014-02-01

    This paper develops an imaging based three-color pyrometer for the monitoring of temperature distribution in a continuous casting billet. A novel optical device, together with an embedded electronic system, is designed to sequentially collect a dark image and three thermal images with specified wavelengths on a same monochromatic charge-coupled-device (CCD). The three thermal images provide the basis for the determination of target temperature, while the dark image is used to online eliminate the dark noise of CCD with a differential method. This image pyrometer is not only independent of target emissivity but also overcomes the dissimilarity of measuring accuracy between the micro-sensors of CCD resulted from the non-uniformity of pixels' intensity response and the vignetting of optical system. Furthermore, a precise two-color temperature field measuring model on the CCD pyrometer is established, based on which a self-adaptive light-integration mechanism is presented. Compared with the traditional fixed light-integration method, the measuring range of the pyrometer is greatly extended and its sensitivity in low temperature segment is improved. The test results in a steel factory demonstrate that the pyrometer is capable of meeting the requirement of surface temperature measurements about casting billets. Reliability and accuracy of measurement results are also discussed herein. PMID:24593387

  10. Comparison of two pyrometers used to calibrate Primary Standards Laboratory's tungsten filament lamps

    SciTech Connect

    Odom, M.K.

    1987-01-01

    The Primary Standards Laboratory presently uses an automatic optical pyrometer with a photomultiplier tube photodetector to calibrate tungsten filament lamps. This pyrometer is compared to a newly designed direct optical pyrometer with a photodiode photodetector. Though the direct pyrometer looks promising, final improvements are necessary to make a conclusive comparison.

  11. Noncontact true temperature measurement. [of levitated sample using laser pyrometer

    NASA Technical Reports Server (NTRS)

    Lee, Mark C.; Allen, James L.

    1987-01-01

    A laser pyrometer has been developed for acquiring the true temperature of a levitated sample. The laser beam is first expanded to cover the entire cross-sectional surface of the target. For calibration of such a system, the reflectivity signal of an ideal 0.95 cm diameter gold-coated sphere (reflectivity = 0.99) is used as the reference for any other real targets. The emissivity of the real target can then be calculated. The overall system constant is obtained by passively measuring the radiance of a blackbody furnace (emissivity = 1.0) at a known, arbitrary temperature. Since the photo sensor used is highly linear over the entire operating temperature range, the true temperature of the target can then be computed. Preliminary results indicate that true temperatures thus obtained are in excellent correlation with thermocouple measured temperatures.

  12. Two-Band Pyrometers Detect Hydrogen Fires

    NASA Technical Reports Server (NTRS)

    Collins, J. David; Youngquist, Robert C.; Simmons, Stephen M.

    1993-01-01

    Two-band infrared pyrometers detect small hydrogen fires at greater distances in full daylight being developed. Detectors utilize part of infrared spectrum in which signals from hydrogen flames 10 to the 3rd power to 10 to the 4th power times as intense as ultraviolet region of current detectors. Utilize low-loss infrared lenses for focusing and for limiting fields of view to screen out spurious signals from nearby sources. Working distances of as much as 100 meters possible. Portable, battery-powered unit gives audible alarm, in form of increase in frequency of tone, when aimed at hydrogen fire.

  13. The Spectropyrometera Practical Multi-wavelength Pyrometer

    NASA Astrophysics Data System (ADS)

    Felice, Ralph A.

    2003-09-01

    An expert-system multi-wavelength pyrometer, commercially available since 1997 and using a spectrophotometer as its detector, has been able to overcome many well-known difficulties of pyrometry, including unknown, changing, and/or spectral dependence of emissivity as well as environmental absorption of radiation. In addition to a spectrophotometer and the usual optics, the instrument includes a computer which analyzes each measurement and then returns the temperature, the tolerance (a real-time measure of accuracy), and the signal strength (a quantity directly related to the emissivity at a chosen wavelength). The computer allows the input data, namely the thermal spectrum for each temperature measurement, to be saved. Accuracy to 0.10 % is routinely achieved.

  14. Measuring Isotope Ratios Across the Solar System

    NASA Technical Reports Server (NTRS)

    Webster, Chris R.; Mahaffy, Paul R.

    2012-01-01

    Stable isotope ratios in C, H, N, O and S are powerful indicators of a wide variety of planetary geophysical processes that can identify origin, transport, temperature history, radiation exposure, atmospheric escape, environmental habitability and biology [1]. For the Allan Hills 84001 meteorite, for example, the (sup 1)(sup 3)C/(sup 1)(sup 2)C ratio identifies it as a Mars (SNC) meteorite; the ??K/??Ar ratio tells us the last time the rock cooled to solid, namely 4 Gya; isotope ratios in (sup 3)He, (sup 2)(sup 1)Ne and (sup 3)?Ar show it was in space (cosmic ray exposure) for 10-20 million years; (sup 1)?C dating that it sat in Antarctica for 13,000 years before discovery; and clumped isotope analysis of (sup 1)?O(sup 1)(sup 3)C(sup 1)?O in its carbonate that it was formed at 18+/-4 ?C in a near-surface aqueous environment [2]. Solar System Formation

  15. CO (Carbon Monoxide Mixing Ratio System) Handbook

    SciTech Connect

    Biraud, S

    2011-02-23

    The main function of the CO instrument is to provide continuous accurate measurements of carbon monoxide mixing ratio at the ARM SGP Central Facility (CF) 60-meter tower (36.607 °N, 97.489 °W, 314 meters above sea level). The essential feature of the control and data acquisition system is to record signals from a Thermo Electron 48C and periodically calibrate out zero and span drifts in the instrument using the combination of a CO scrubber and two concentrations of span gas (100 and 300 ppb CO in air). The system was deployed on May 25, 2005.

  16. Hydraulic system for a ratio change transmission

    DOEpatents

    Kalns, Ilmars

    1981-01-01

    Disclosed is a drive assembly (10) for an electrically powered vehicle (12). The assembly includes a transaxle (16) having a two-speed transmission (40) and a drive axle differential (46) disposed in a unitary housing assembly (38), an oil-cooled prime mover or electric motor (14) for driving the transmission input shaft (42), an adapter assembly (24) for supporting the prime mover on the transaxle housing assembly, and a hydraulic system (172) providing pressurized oil flow for cooling and lubricating the electric motor and transaxle and for operating a clutch (84) and a brake (86) in the transmission to shift between the two-speed ratios of the transmission. The adapter assembly allows the prime mover to be supported in several positions on the transaxle housing. The brake is spring-applied and locks the transmission in its low-speed ratio should the hydraulic system fail. The hydraulic system pump is driven by an electric motor (212) independent of the prime mover and transaxle.

  17. Flexible Conversion Ratio Fast Reactor Systems Evaluation

    SciTech Connect

    Neil Todreas; Pavel Hejzlar

    2008-06-30

    Conceptual designs of lead-cooled and liquid salt-cooled fast flexible conversion ratio reactors were developed. Both concepts have cores reated at 2400 MWt placed in a large-pool-type vessel with dual-free level, which also contains four intermediate heat exchanges coupling a primary coolant to a compact and efficient supercritical CO2 Brayton cycle power conversion system. Decay heat is removed passively using an enhanced Reactor Vessel Auxiliary Cooling System and a Passive Secondary Auxiliary Cooling System. The most important findings were that (1) it is feasible to design the lead-cooled and salt-cooled reactor with the flexible conversion ratio (CR) in the range of CR=0 and CR=1 n a manner that achieves inherent reactor shutdown in unprotected accidents, (2) the salt-cooled reactor requires Lithium thermal Expansion Modules to overcme the inherent salt coolant's large positive coolant temperature reactivity coefficient, (3) the preferable salt for fast spectrum high power density cores is NaCl-Kcl-MgCl2 as opposed to fluoride salts due to its better themal-hydraulic and neutronic characteristics, and (4) both reactor, but attain power density 3 times smaller than that of the sodium-cooled reactor.

  18. Shock Temperatures of Soda Lime Glass Measured by an Optical Pyrometer

    NASA Astrophysics Data System (ADS)

    Kobayashi, Takamichi; Sekine, Toshimori; Fat'yanov, O. V.; Takazawa, Eiichi; Zhu, Y. Q.

    1997-07-01

    An optical pyrometer has been used to measure shock temperatures of soda lime glass in a pressure range 58-110 GPa. This pyrometer consists of two parts, i.e., an OMA which provides a radiation spectrum over a visible range ( ~500 nm window) and a 4-channel PMT system which provides a time-dependent behavior of shock temperatures. The measured radiation spectra are compared with black body radiation curves to estimate the shock temperatures and emissivities. The obtained shock temperarures for the above pressure range are 2800-5500 K and nearly a linear relationship between the shock temperature and the shock pressure has been observed. It seems that obtained temperatures represent melted glass temperatures. Shock properties such as shock velocity and particle velocity of soda lime glass can be estimated and compared with those of crystal quartz and fused quartz.

  19. Multicolor pyrometer for materials processing in space, phase 2

    NASA Technical Reports Server (NTRS)

    Frish, Michael; Frank, Jonathan; Beerman, Henry

    1988-01-01

    The program goals were to design, construct, and program a prototype passive imaging pyrometer capable of measuring, as accurately as possible, the temperature distribution across the surface of a moving object suspended in space.

  20. Active millimeter-wave pyrometer

    NASA Astrophysics Data System (ADS)

    Woskov, P. P.; Cohn, D. R.; Rhee, D. Y.; Thomas, P.; Titus, C. H.; Surma, J. E.

    1995-08-01

    A 135 GHz heterodyne receiver with a rotatable graphite waveguide/mirror system has been implemented on a waste remediation direct-current arc furnace for internal surface temperature measurements. The linear temperature measurement range extends from <1 to approximately 15,000 C relative to ambient with a simultaneous capability to monitor surface reflectivity with the local oscillator leakage. Reliable and robust operation on a continuous 24 h basis in a smoky, dirty furnace environment is demonstrated for a total of five furnace runs reaching a maximum temperature of 2200 C. Complete temperature profile measurements with approximately 5 cm spatial resolution clearly documented thermal gradients on the slag melt surface and refractory walls and ceiling for all operating regimes of the furnace. The unique active probing capability of this instrument provided additional real-time information on melt surface turbulence, changing furnace wall emissivity, and millimeter-wave optic losses inside the furnace.

  1. Active millimeter-wave pyrometer

    SciTech Connect

    Woskov, P.P.; Cohn, D.R.; Rhee, D.Y.; Thomas, P.; Titus, C.H.; Surma, J.E.

    1995-08-01

    A 135 GHz heterodyne receiver with a rotatable graphite waveguide/mirror system has been implemented on a waste remediation direct-current arc furnace for internal surface temperature measurements. The linear temperature measurement range extends from {lt}1{degree} to approximately 15,000 {degree}C relative to ambient with a simultaneous capability to monitor surface reflectivity with the local oscillator leakage. Reliable and robust operation on a continuous 24 h basis in a smoky, dirty furnace environment is demonstrated for a total of five furnace runs reaching a maximum temperature of 2200 {degree}C. Complete temperature profile measurements with approximately 5 cm spatial resolution clearly documented thermal gradients on the slag melt surface and refractory walls and ceiling for all operating regimes of the furnace. The unique active probing capability of this instrument provided additional real-time information on melt surface turbulence, changing furnace wall emissivity, and millimeter-wave optic losses inside the furnace. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  2. Method and Apparatus for Polaradiometric Pyrometer

    NASA Technical Reports Server (NTRS)

    Abtahi, Ali A. (inventor)

    1994-01-01

    A radiation pyrometer for measuring the true temperature of a body is provided by detecting and measuring thermal radiation from the body based on the principle that the effects of angular emission I(sub 1) and reflection I(sub 2) on the polarization states p and s of radiation are complementary such that upon detecting the combined partial polarization state components I(sub p) = I(sub 1p) + I(sub 2p) and I(sub s) = I(sub 1s) + I(sub 2s) and adjusting the intensity of the variable radiation source of the reflected radiation I(sub 2) until the combined partial radiation components I(sub p) and I(sub s) are equal, the effects of emissivity as well as diffusivity of the surface of the body are eliminated, thus obviating the need for any post processing of brightness temperature data.

  3. Measuring Isotope Ratios Across the Solar System

    NASA Astrophysics Data System (ADS)

    Webster, C. R.; Mahaffy, P. R.

    2012-10-01

    We will overview how stable isotope ratios in C, H, N, O and S are powerful indicators of a wide variety of planetary processes identifying origin, transport, temperature history, radiation exposure, atmospheric escape, habitability, and biology.

  4. Application of the Self Calibrating Emissivity and/or Transmissivity Independent Multiwavelength Pyrometer in an Intense Ambient Radiation Environment

    NASA Technical Reports Server (NTRS)

    Ng, Daniel

    1996-01-01

    The NASA self calibrating multiwavelength pyrometer is a recent addition to the list of pyrometers used in remote temperature measurement in research and development. The older one-color, two-color, and the disappearing filament pyrometers, as well as the multicolor and early multiwavelength pyrometers, all do not operate successfully in situations in which strong ambient radiation coexists with radiation originating from the measured surface. In such situations radiation departing from the target surface arrives at the pyrometer together with radiation coming from another source either directly or through reflection. Unlike the other pyrometers, the self calibrating multiwavelength pyrometer can still calibrate itself and measure the temperatures in this adverse environment.

  5. Temperature Measurement of Ceramic Materials Using a Multiwavelength Pyrometer

    NASA Technical Reports Server (NTRS)

    Ng, Daniel; Fralick, Gustave

    1999-01-01

    The surface temperatures of several pure ceramic materials (alumina, beryllia, magnesia, yittria and spinel) in the shape of pellets were measured using a multiwavelength pyrometer. In one of the measurements, radiation signal collection is provided simply by an optical fiber. In the other experiments, a 4.75 inch (12 cm) parabolic mirror collects the signal for the spectrometer. Temperature measurement using the traditional one- and two-color pyrometer for these ceramic materials is difficult because of their complex optical properties, such as low emissivity which varies with both temperature and wavelength. In at least one of the materials, yittria, the detected optical emission increased as the temperature was decreased due to such emissivity variation. The reasons for such changes are not known. The multiwavelength pyrometer has demonstrated its ability to measure surface temperatures under such conditions. Platinum electrodes were embedded in the ceramic pellets for resistance measurements as the temperature changed.

  6. Imaging pyrometer for monitoring the surface temperature of a spray-formed steel billet

    NASA Astrophysics Data System (ADS)

    Parker, Ronald A.; Allor, Richard

    2001-03-01

    A two-wavelength, imaging pyrometer was developed for real- time measurement of the surface temperature distribution of a spray-formed steel billet. This new spray-forming process is used to deposit bulk steel on a ceramic substrate in a surface temperature range of 300 degrees C to 400 degrees C, using four, twin-wire arc plasma torches. These steel billets are used as tools in metal forming processes, injection molding and die casting tools, and other processes that may need hard tooling, such as the automotive industry. The steel billet must be formed with a uniform, surface temperature distribution to minimize the thermal stresses within the steel, throughout the process. The imaging pyrometer uses a near-IR InGaAs CCD camera with high quantum efficiency from 0.95 to 1.75 microns. The wavelengths of 1.40 and 1.65 microns were selected to sense the low temperature billet. The camera has a format of 320 x 240 pixels with a pixel spacing of 30 microns and an integral 12-bit A/D converter with both video and digital outputs. The design of the pyrometer provides a working distance of 2.2 meters and a field of view of 0.6 meters. This technical paper describes the calibrations and initial measurement results obtained in a spray forming facility at the Ford Research Laboratory. The calibration provided intensity ratio measurements for surface temperatures ranging from 200 degrees C to 300 degrees C, the expected range of operation. The initial measurements described here depict the surface temperature distribution of the steel billet throughout the spray forming process, typically lasting several hours.

  7. Direct emissivity measurements on liquids and corrections to multi-color pyrometers

    NASA Technical Reports Server (NTRS)

    Nordine, Paul C.; Schiffman, Robert A.

    1988-01-01

    Optical pyrometry provides a means for non-contact temperature measurements whose accuracy depends on the accuracy with which specimen emittance is known. Two methods for obtaining the required emittance data are discussed in which the emittance is determined from measurements of the wavelength or polarization dependence of light emitted by the specimen. The spectral technique, multi-color pyrometry, yields apparent values for specimen emittance and temperature from emitted intensity measurements at two or more wavelengths. Emittance corrections cannot be eliminated by increasing the number of spectral intensity measurements required by an n-color pyrometer. Even if this were possible, the accuracy of temperature measurements by n-color pyrometry decreases with n such that pyrometers that require four intensity measurements would be impractical. In contrast, emittance values and corrections for one-color pyrometers can be accurately measured by the polarized light technique. The polarized light technique involves measurement of the degree of polarization for light emitted at an angle of 45 deg to the specimen normal. The reflectivities (r) for light polarized parallel (p) and normal (n) to the plane of emission are related by r(p) = r(n) squared. This leads to a simple relation between the intensity ratio for light emitted in the two polarized states and the emittance, i.e., e(n) = 2 - I(p)/I(n). The true specimen temperature is also obtained if absolute intensities are measured. Delvelopment of the polarized light technique in combination with one-color optical pyrometry is recommended to achieve accurate non-contact temperature measurements on liquids.

  8. Temperature measurement in WTE boilers using suction pyrometers.

    PubMed

    Rinaldi, Fabio; Najafi, Behzad

    2013-01-01

    The temperature of the flue-gas in the post combustion zone of a waste to energy (WTE) plant has to be maintained within a fairly narrow range of values, the minimum of which is prescribed by the European Waste Directive 2000/76/CE, whereas the maximum value must be such as to ensure the preservation of the materials and the energy efficiency of the plant. A high degree of accuracy in measuring and controlling the aforementioned temperature is therefore required. In almost the totality of WTE plants this measurement process is carried out by using practical industrial thermometers, such as bare thermocouples and infrared radiation (IR) pyrometers, even if affected by different physical contributions which can make the gas temperature measurements incorrect. The objective of this paper is to analyze errors and uncertainties that can arise when using a bare thermocouple or an IR pyrometer in a WTE plant and to provide a method for the in situ calibration of these industrial sensors through the use of suction pyrometers. The paper describes principle of operation, design, and uncertainty contributions of suction pyrometers, it also provides the best estimation of the flue-gas temperature in the post combustion zone of a WTE plant and the estimation of its expanded uncertainty. PMID:24248279

  9. Temperature Measurement in WTE Boilers Using Suction Pyrometers

    PubMed Central

    Rinaldi, Fabio; Najafi, Behzad

    2013-01-01

    The temperature of the flue-gas in the post combustion zone of a waste to energy (WTE) plant has to be maintained within a fairly narrow range of values, the minimum of which is prescribed by the European Waste Directive 2000/76/CE, whereas the maximum value must be such as to ensure the preservation of the materials and the energy efficiency of the plant. A high degree of accuracy in measuring and controlling the aforementioned temperature is therefore required. In almost the totality of WTE plants this measurement process is carried out by using practical industrial thermometers, such as bare thermocouples and infrared radiation (IR) pyrometers, even if affected by different physical contributions which can make the gas temperature measurements incorrect. The objective of this paper is to analyze errors and uncertainties that can arise when using a bare thermocouple or an IR pyrometer in a WTE plant and to provide a method for the in situ calibration of these industrial sensors through the use of suction pyrometers. The paper describes principle of operation, design, and uncertainty contributions of suction pyrometers, it also provides the best estimation of the flue-gas temperature in the post combustion zone of a WTE plant and the estimation of its expanded uncertainty. PMID:24248279

  10. Elevated sacroilac joint uptake ratios in systemic lupus erythematosus

    SciTech Connect

    De Smet, A.A.; Mahmood, T.; Robinson, R.G.; Lindsley, H.B.

    1984-08-01

    Sacroiliac joint radiographs and radionuclide sacroiliac joint uptake ratios were obtained on 14 patients with active systemic lupus erythematosus. Elevated joint ratios were found unilaterally in two patients and bilaterally in seven patients when their lupus was active. In patients whose disease became quiescent, the uptake ratios returned to normal. Two patients had persistently elevated ratios with continued clinical and laboratory evidence of active lupus. Mild sacroiliac joint sclerosis and erosions were detected on pelvic radiographs in these same two patients. Elevated quantitative sacroiliac joint uptake ratios may occur as a manifestation of active systemic lupus erythematosus.

  11. Ratio

    NASA Astrophysics Data System (ADS)

    Webster, Nathan A. S.; Pownceby, Mark I.; Madsen, Ian C.; Studer, Andrew J.; Manuel, James R.; Kimpton, Justin A.

    2014-12-01

    Effects of basicity, B (CaO:SiO2 ratio) on the thermal range, concentration, and formation mechanisms of silico-ferrite of calcium and aluminum (SFCA) and SFCA-I iron ore sinter bonding phases have been investigated using an in situ synchrotron X-ray diffraction-based methodology with subsequent Rietveld refinement-based quantitative phase analysis. SFCA and SFCA-I phases are the key bonding materials in iron ore sinter, and improved understanding of the effects of processing parameters such as basicity on their formation and decomposition may assist in improving efficiency of industrial iron ore sintering operations. Increasing basicity significantly increased the thermal range of SFCA-I, from 1363 K to 1533 K (1090 °C to 1260 °C) for a mixture with B = 2.48, to ~1339 K to 1535 K (1066 °C to 1262 °C) for a mixture with B = 3.96, and to ~1323 K to 1593 K (1050 °C to 1320 °C) at B = 4.94. Increasing basicity also increased the amount of SFCA-I formed, from 18 wt pct for the mixture with B = 2.48 to 25 wt pct for the B = 4.94 mixture. Higher basicity of the starting sinter mixture will, therefore, increase the amount of SFCA-I, considered to be more desirable of the two phases. Basicity did not appear to significantly influence the formation mechanism of SFCA-I. It did, however, affect the formation mechanism of SFCA, with the decomposition of SFCA-I coinciding with the formation of a significant amount of additional SFCA in the B = 2.48 and 3.96 mixtures but only a minor amount in the highest basicity mixture. In situ neutron diffraction enabled characterization of the behavior of magnetite after melting of SFCA produced a magnetite plus melt phase assemblage.

  12. Alternative calibration techniques for high-speed pyrometers in shock experiments

    NASA Astrophysics Data System (ADS)

    Partouche-Sebban, D.; Holtkamp, D. B.; Rodriguez, P.; Stone, J. B.; Borror, S. D.; Kruschwitz, C. A.; Young, J. A.

    2005-01-01

    Optical pyrometry is widely used in industry and research laboratories to perform surface temperature measurements of sample materials. These shock physics experiments are normally conducted at powder or gas gun facilities or at facilities where high explosives can be used as a shock wave source, and using high-speed pyrometers that are usually calibrated by using a blackbody source. But, electrical power, time, and space can be limiting factors in such facilities, and blackbody calibration can be difficult. Crucial parts of the experimental setup (fibers, lenses, and/or mirrors) are destroyed in such experiments, and the pyrometry system must be recalibrated before each experiment. We have developed a calibration technique using integrating-sphere sources that allows us to calibrate pyrometers more rapidly and easily than with blackbodies. Two different integrating-sphere systems are described to cover the wavelength range generally used in pyrometry studies. The characterization of these systems is fully detailed including measurements of their spectral radiances. A discussion of the advantages and drawbacks of both calibration sources is given.

  13. Concept of planetary gear system to control fluid mixture ratio

    NASA Technical Reports Server (NTRS)

    Mcgroarty, J. D.

    1966-01-01

    Mechanical device senses and corrects for fluid flow departures from the selected flow ratio of two fluids. This system has been considered for control of rocket engine propellant mixture control but could find use wherever control of the flow ratio of any two fluids is desired.

  14. Multi-color pyrometer for materials processing in space

    NASA Technical Reports Server (NTRS)

    Frish, Michael B.; Spencer, Mark N.; Wolk, Nancy E.; Werner, Jennifer S.; Miranda, Henry A., Jr.

    1988-01-01

    The design, construction and calibration of a computer-linked multicolor pyrometer is described. The device was constructed for ready adaptation to a spacecraft and for use in the control of thermal processes for manufacturing materials in space. The pyrometer actually uses only one color at a time, and is relatively insensitive to uncertainties in the heated object's emissivity because the product of the color and the temperature has been selected to be within a regime where the radiant energy emitted from the body increases very rapidly with temperature. The instrument was calibrated and shown to exceed its design goal of temperature measurements between 300 and 2000 C, and its accuracy in the face of imprecise knowledge of the hot object's emissivity was demonstrated.

  15. Deep, Low Mass Ratio Overcontact Binary Systems. V. The Lowest Mass Ratio Binary V857 Herculis

    NASA Astrophysics Data System (ADS)

    Qian, S.-B.; Zhu, L.-Y.; Soonthornthum, B.; Yuan, J.-Z.; Yang, Y.-G.; He, J.-J.

    2005-09-01

    Charge-coupled device (CCD) photometric light curves in the B, V, and R bands of the complete eclipsing binary star V857 Her are presented. It is shown that the light curves of the W UMa-type binary are symmetric and of A type according to Binnendijk's classification. Our four epochs of light minimum along with others compiled from the literature were used to revise the period and study the period change. Weak evidence indicates that the orbital period of V857 Her may show a continuous increase at a rate of dP/dt=+2.90×10-7 days yr-1. The photometric parameters of the system were determined with the 2003 version of the Wilson-Devinney code. It is shown that V857 Her is a deep overcontact binary system with f=83.8%+/-5.1%. The derived mass ratio of q=0.06532+/-0.0002 suggests that it has the lowest mass ratio among overcontact binary systems. As the orbital period increases, the decrease of the mass ratio will cause it to evolve into a single rapidly rotating star when it meets the more familiar criterion that the orbital angular momentum be less than 3 times the total spin angular momentum. To understand the evolutionary state of the system, long-term photometric monitoring and spectroscopic observations will be required.

  16. Use of a Multiwavelength Pyrometer in Several Elevated Temperature Aerospace Applications

    NASA Technical Reports Server (NTRS)

    Ng, Daniel; Fralick, Gustave

    2001-01-01

    A multiwavelength pyrometer was developed for applications unique to aerospace environments. It was shown to be a useful and versatile technique for measuring temperature, even when the emissivity is unknown. It has also been used to measure the surface temperatures of ceramic zircomia thermal barrier coatings and alumina. The close agreement between pyrometer and thin film thermocouple temperatures provided an independent check. Other applications of the multiwavelength pyrometer are simultaneous surface and bulk temperature measurements of a transparent material, and combustion gas temperature measurement using a special probe interfaced to the multiwavelength pyrometer via an optical fiber. The multiwavelength pyrometer determined temperature by transforming the radiation spectrum in a broad wavelength region to produce a straight line (in a certain spectral region), whose intercept in the vertical axis gives the temperature. Implicit in a two-color pyrometer is the assumption of wavelength independent emissivity. Though the two data points of a two-color pyrometer similarly processed would result immediately in a similar straight line to give the unknown temperature, the two-color pyrometer lacks the greater data redundancy of the multiwavelength pyrometer, which enables it to do so with improved accuracy. It also confirms that emissivity is indeed wavelength independent, as evidenced by a multitude of the data lying on a simple straight line. The multiwavelength pyrometer was also used to study the optical transmission properties of a nanostructured material from which a quadratic exponential functional frequency dependence of its spectral transmission was determined. Finally, by operating the multiwavelength pyrometer in a very wide field of view mode, the surface temperature distribution of a large hot surface was obtained through measurement of just a single radiation spectrum.

  17. System and method for high precision isotope ratio destructive analysis

    DOEpatents

    Bushaw, Bruce A; Anheier, Norman C; Phillips, Jon R

    2013-07-02

    A system and process are disclosed that provide high accuracy and high precision destructive analysis measurements for isotope ratio determination of relative isotope abundance distributions in liquids, solids, and particulate samples. The invention utilizes a collinear probe beam to interrogate a laser ablated plume. This invention provides enhanced single-shot detection sensitivity approaching the femtogram range, and isotope ratios that can be determined at approximately 1% or better precision and accuracy (relative standard deviation).

  18. Rapid exchange effects on isotope ratios in groundwater systems: 2. Flow investigation using Sr isotope ratios

    NASA Astrophysics Data System (ADS)

    Johnson, Thomas M.; Depaolo, Donald J.

    1997-01-01

    Sr isotope ratios were measured in groundwater, whole rock digestions, and cation exchange extracts from a clay-rich groundwater system at Ernest O. Lawrence Berkeley National Laboratory and were used to constrain flow velocities and search for preferential flow paths. In the Orinda formation siltstone, 87Sr/86Sr increases strongly over tens of meters along presumed flow paths, indicating slow groundwater flow. Dissolved Sr is close to isotopic equilibrium with the exchangeable Sr in the clays, and the observed 87Sr/86Sr increase is interpreted as a cation exchange front moving slowly through the unit combined with dissolution of minerals with relatively high 87Sr/86Sr ratios. The data are inverted using a one-dimensional transport-dissolution-exchange model; the results indicate long-term average flow velocities of less than 0.2 m/yr which are consistent with 14C measurements. The data suggest a lack of strong preferential flow paths through this unit.

  19. Volume-ratio calibration system for vacuum gages

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Volume-ratio calibration system consists of a gas source, high pressure gauge, small volume tank, large volume chamber, plus appropriate piping, valves, and vacuum source. This system used in conjunction with commercial vacuum gauges evaluates its ability to accurately produce desired pressures in the .000001 to .01 torr range.

  20. Air-fuel ratio control system for internal combustion engines

    SciTech Connect

    Kojima, S.; Wataya, S.; Nishiyama, R.

    1988-08-23

    This patent describes an air-fuel ratio control system for internal combustion engines, comprising: an air-fuel ratio sensor mounted in an exhaust pipe of an internal combustion engine and adapted to produce an output indicative of the air-fuel ratio of a mixture supplied to the engine on the basis of the composition of exhaust gases in the exhaust pipe; heating means for heating the air-fuel ratio sensor; an engine operation sensor adapted to sense whether the engine has been stopped; and control means for controlling the heating means such that is operated for a predetermined time after the engine operation sensor has sensed that the internal combustion engine has been stopped.

  1. Air-fuel ratio control system for internal combustion engines

    SciTech Connect

    Kojima, S.; Nishiyama, R.; Wataya, S.

    1988-06-28

    An air-fuel ratio control system is described for internal combustion engines, comprising: an air-fuel ratio sensor mounted in an exhaust pipe of an internal combustion engine and adapted to produce an output indicative of the air-fuel ratio of a mixture supplied to the engine on the basis for the composition of exhaust gases in the exhaust pipe; heating means for heating the air-fuel ratio sensor; a temperature sensor for sensing the temperature of the internal combustion engine; an engine operation sensor adapted to sense whether the engine has been stopped; and control means for allowing, when the engine operation sensor has sensed that the internal combustion engine has been stopped while the engine temperature sensed by the temperature sensor is below a predetermined level, the heating means to operate for a predetermined time after the engine operation sensor has sensed that the internal combustion engine has been stopped.

  2. Development of a multi-point two-color pyrometer for tube and wall temperature and emissivity measurement at the CFFF

    NASA Astrophysics Data System (ADS)

    Benton, R. D.; Jang, P. R.

    The Diagnostic Instrumentation and Analysis Laboratory (DIAL) has been actively engaged in developing and applying advanced optical diagnostic techniques and instrumentation systems to high temperature coal-fired gas streams for over a decade. DIAL's systems have been used primarily in support of the US Department of Energy's (DOE) magnetohydrodynamic (MHD) research program. One of the earliest diagnostic systems developed by DIAL was a two color pyrometer (TCP). The TCP is used to measure surface temperature and emissivity. This system has been used extensively to make measurements in support of the national MHD program. In this system, two commercial single-color pyrometers and a microprocessor system were used to form a TCP to make accurate measurements of surfaces of unknown emissivity and temperature. This paper describes an improvement in the DIAL TCP which provides for near simultaneous multipoint measurements, reduced dependence on electronic circuits, and a greatly improved data display system. Commercial two-color pyrometer systems are not suitable for our work because they do not provide for emissivity measurement. The emissivity measurement provides insight into changes in surface characteristics and is an important consideration in our work. A second and important reason for our development of this system is the need to make simultaneous measurements at widely separated points. Finally, the data measured by this system is stored on magnetic media and can be correlated with other measurements on the system, e.g. furnace, under study.

  3. DETECTION OF LOW-MASS-RATIO STELLAR BINARY SYSTEMS

    SciTech Connect

    Gullikson, Kevin; Dodson-Robinson, Sarah

    2013-01-01

    O- and B-type stars are often found in binary systems, but the low binary mass-ratio regime is relatively unexplored due to observational difficulties. Binary systems with low mass ratios may have formed through fragmentation of the circumstellar disk rather than molecular cloud core fragmentation. We describe a new technique sensitive to G- and K-type companions to early B stars, a mass ratio of roughly 0.1, using high-resolution, high signal-to-noise spectra. We apply this technique to a sample of archived VLT/CRIRES observations of nearby B stars in the CO bandhead near 2300 nm. While there are no unambiguous binary detections in our sample, we identify HIP 92855 and HIP 26713 as binary candidates warranting follow-up observations. We use our non-detections to determine upper limits to the frequency of FGK stars orbiting early B-type primaries.

  4. Evaluation of Raytek infrared pyrometer for continuous propellant temperature measurement

    NASA Technical Reports Server (NTRS)

    Dykstra, Mark D.

    1990-01-01

    The primary purpose of this evaluation was to determine if the Raytek IR pyrometer that was installed in the 600 gallon propellant mixers could be used to provide a continuous, accurate, reliable measurement of the propellant temperature during mixing. The Raytek infrared sensor is not recommended to be used for controlling propellant temperature nor for inspection buy-off. The first part of the evaluation was to determine the accuracy of the sensor in measuring the propellant temperature. The second part was to determine the reliability of the air purge design in preventing contamination of the IR window.

  5. The Rover Environmental Monitoring Station Ground Temperature Sensor: A Pyrometer for Measuring Ground Temperature on Mars

    PubMed Central

    Sebastián, Eduardo; Armiens, Carlos; Gómez-Elvira, Javier; Zorzano, María P.; Martinez-Frias, Jesus; Esteban, Blanca; Ramos, Miguel

    2010-01-01

    We describe the parameters that drive the design and modeling of the Rover Environmental Monitoring Station (REMS) Ground Temperature Sensor (GTS), an instrument aboard NASA’s Mars Science Laboratory, and report preliminary test results. REMS GTS is a lightweight, low-power, and low cost pyrometer for measuring the Martian surface kinematic temperature. The sensor’s main feature is its innovative design, based on a simple mechanical structure with no moving parts. It includes an in-flight calibration system that permits sensor recalibration when sensor sensitivity has been degraded by deposition of dust over the optics. This paper provides the first results of a GTS engineering model working in a Martian-like, extreme environment. PMID:22163405

  6. The Rover Environmental Monitoring Station Ground Temperature Sensor: a pyrometer for measuring ground temperature on Mars.

    PubMed

    Sebastián, Eduardo; Armiens, Carlos; Gómez-Elvira, Javier; Zorzano, María P; Martinez-Frias, Jesus; Esteban, Blanca; Ramos, Miguel

    2010-01-01

    We describe the parameters that drive the design and modeling of the Rover Environmental Monitoring Station (REMS) Ground Temperature Sensor (GTS), an instrument aboard NASA's Mars Science Laboratory, and report preliminary test results. REMS GTS is a lightweight, low-power, and low cost pyrometer for measuring the Martian surface kinematic temperature. The sensor's main feature is its innovative design, based on a simple mechanical structure with no moving parts. It includes an in-flight calibration system that permits sensor recalibration when sensor sensitivity has been degraded by deposition of dust over the optics. This paper provides the first results of a GTS engineering model working in a Martian-like, extreme environment. PMID:22163405

  7. Application of a high speed, low temperature infrared pyrometer in pulsed power experiments

    NASA Astrophysics Data System (ADS)

    Partouche-Sebban, David; Holtkamp, David B.; Bartsch, R. Richard; Lee, Huan; Schmitt, Gerald G.

    2001-07-01

    A new, multichannel infrared (IR) pyrometer has been constructed that is capable of measuring low temperature changes (<100 C) at high speed (multi-MHz). The pyrometer has four IR channels spanning 1-11 ?m and uses 1 mm optical fibers to relay the light from the center of a pulsed power experiment to the detectors. Broad IR passbands are used to increase sensitivity while preserving high accuracy in the temperature measurement (<15% for the absolute temperature (K) up to 1300 K). An application of the pyrometer in material property measurements of high strain at high strain rate is described.

  8. Evaluation and comparison of three IR detectors and three amplifier designs for a new high-speed IR pyrometer

    NASA Astrophysics Data System (ADS)

    Young, J. A.; Borror, S.; Obst, A. W.; Payton, J. R.; Seifter, A.

    2005-08-01

    At Los Alamos National Laboratory (LANL), a high-speed, four-wavelength, infrared (IR) pyrometer has been used for surface temperature measurements in shock-physics experiments for several years. The pyrometer uses solid-state detectors and a single fiber-optic cable for transmission of light from the target surface to the detectors. This instrument has recently been redesigned for an upcoming experiment at the Nevada Test Site (NTS). Three different IR detectors (two HgCdTe variants as well as the existing InSb chip) were compared for sensitivity, signal-to-noise ratio, and bandwidth. Of major concern was detector amplifier recovery time from overload saturation. In shock-physics experiments, a short but very bright precursor frequently accompanies shock breakout (often from trapped air). This precursor can saturate the amplifier and may "swamp-out" the signal of interest before the amplifier recovers. With this in mind, we evaluated two new amplifier designs by the Perry Amplifier Company for linearity, signal-to-noise characteristics, gain, and saturation recovery time. This paper describes experimental setup for detector comparison and results obtained. Furthermore, we discuss new amplifier design and suitability for high-speed infrared pyrometry in shock physics experiments.

  9. Evaluation and comparison of three IR detectors and three amplifier designs for a new, high-speed IR pyrometer

    SciTech Connect

    J.A. Young, S. Borrora, A.W. Obst, J.R. Payton, A. Seifter

    2005-01-01

    At Los Alamos National Laboratory (LANL), a high-speed, four-wavelength, infrared (IR) pyrometer has been used for surface temperature measurements in shock-physics experiments for several years. The pyrometer uses solid state detectors and a single fiber-optic cable for transmission of light from the target surface to the detectors. This instrument has recently been redesigned for an upcoming experiment at the Nevada Test Site (NTS). Three different IR detectors (two HgCdTe variants as well as the existing InSb chip) were compared for sensitivity, signal-to-noise ratio, and bandwidth. Of major concern was detector amplifier recovery time from overload saturation. In shock physics experiments, a short but very bright precursor frequently accompanies shock breakout (often from trapped air). This precursor can saturate the amplifier and may ''swamp-out'' the signal of interest before the amplifier recovers. With this in mind, we evaluated two new amplifier designs by the Perry Amplifier Company for linearity, signal-to-noise characteristics, gain, and saturation recovery time. This paper describes experimental setup for detector comparison and results obtained. Furthermore, we discuss new amplifier design and suitability for highspeed infrared pyrometry in shock physics experiments.

  10. Multi-spectral pyrometer for gas turbine blade temperature measurement

    NASA Astrophysics Data System (ADS)

    Gao, Shan; Wang, Lixin; Feng, Chi

    2014-09-01

    To achieve the highest possible turbine inlet temperature requires to accurately measuring the turbine blade temperature. If the temperature of blade frequent beyond the design limits, it will seriously reduce the service life. The problem for the accuracy of the temperature measurement includes the value of the target surface emissivity is unknown and the emissivity model is variability and the thermal radiation of the high temperature environment. In this paper, the multi-spectral pyrometer is designed provided mainly for range 500-1000°, and present a model corrected in terms of the error due to the reflected radiation only base on the turbine geometry and the physical properties of the material. Under different working conditions, the method can reduce the measurement error from the reflect radiation of vanes, make measurement closer to the actual temperature of the blade and calculating the corresponding model through genetic algorithm. The experiment shows that this method has higher accuracy measurements.

  11. Characterizing the Period Ratio Distribution of Kepler Exoplanetary Systems

    NASA Astrophysics Data System (ADS)

    Conaway, James L.; Ragozzine, Darin

    2016-01-01

    Many of the exoplanetary systems discovered by the Kepler space telescope demonstrate unusual properties which need to be explored in order to better understand planetary system formation and evolution. Among these interesting properties is an excess in the number of planets orbiting in resonance or near-resonance with their neighbors. The prevailing assumption in the planetary sciences community is that these are real features of the exoplanet population, but many theories developed on this assumption produce a resonance structure quite different from what we see. In our work we explore the possibility that the actual resonances may not be as we observe them, and may instead be explained by a combination of real resonance features and/or observational bias resulting from geometric effects. In particular, if the near-resonant systems have a different inclination distribution than other systems, then it is possible for them to be over or under-represented.We analyze the existing Kepler data and generate models which approximately represent the empirical period ratio distribution. The 2:1 and 3:2 just-wide-of-resonance excesses are included in the model, along with the deficit of period ratios just short of the 2:1 resonance. We test the Kepler data set against these models using the Python emcee package in order to determine the best-fit parameters for each model. We then address the inclination distribution question by generating two-planet systems with different inclination distributions for the near-resonant systems. We use the CORBITS package (https://github.com/jbrakensiek/CORBITS, Brakensiek & Ragozzine, submitted) to determine the probability of detecting both planets in transit. These tests adjust the relative sizes of the resonance excesses as well as orbital parameters (primarily inclination and nodal alignments) in order to determine which combinations of parameters would create in an observational bias resulting in the resonance excesses seen in the Kepler data.Initial results using first-approximation synthetic data show that some of the observed resonance excesses can be created in the observed data purely from geometric effects resulting from inclination varying as a function of period ratio.

  12. Noise Measurements of High Aspect Ratio Distributed Exhaust Systems

    NASA Technical Reports Server (NTRS)

    Bridges, James

    2015-01-01

    This paper covers far-field acoustic measurements of a family of rectangular nozzles with aspect ratio 8, in the high subsonic flow regime. Several variations of nozzle geometry, commonly proposed for embedded exhaust systems, are explored, including bevels, slants, single broad chevrons and notches, and internal septae. Far-field acoustic results, presented previously for the simple rectangular nozzle, showed that increasing aspect ratio increases the high frequency noise, especially directed in the plane containing the minor axis of the nozzle. Detailed changes to the nozzle geometry generally made little difference in the noise, and the differences were greatest at low speed. Having an extended lip on one broad side ('bevel') did produce up to 3dB more noise in all directions, while extending the lip on the narrow side ('slant') produced up to 2dB more noise, primarily on the side with the extension. Adding a single, non-intrusive chevron, made no significant change to the noise, while inverting the chevron ('notch') produced up to 2dB increase in the noise. Having internal walls ('septae') within the nozzle, such as would be required for structural support or when multiple fan ducts are aggregated, reduced the noise of the rectangular jet, but could produce a highly directional shedding tone from the septae trailing edges. Finally, a nozzle with both septae and a beveled nozzle, representative of the exhaust system envisioned for a distributed propulsion aircraft with a common rectangular duct, produced almost as much noise as the beveled nozzle, with the septae not contributing much reduction in noise.

  13. Noise Measurements of High Aspect Ratio Distributed Exhaust Systems

    NASA Technical Reports Server (NTRS)

    Bridges, James E.

    2015-01-01

    This paper covers far-field acoustic measurements of a family of rectangular nozzles with aspect ratio 8, in the high subsonic flow regime. Several variations of nozzle geometry, commonly found in embedded exhaust systems, are explored, including bevels, slants, single broad chevrons and notches, and internal septae. Far-field acoustic results, presented previously for the simple rectangular nozzle, showed that increasing aspect ratio increases the high frequency noise, especially directed in the plane containing the minor axis of the nozzle. Detailed changes to the nozzle geometry generally made little difference in the noise, and the differences were greatest at low speed. Having an extended lip on one broad side (bevel) did produce up to 3 decibels more noise in all directions, while extending the lip on the narrow side (slant) produced up to 2 decibels more noise, primarily on the side with the extension. Adding a single, non-intrusive chevron, made no significant change to the noise, while inverting the chevron (notch) produced up to 2decibels increase in the noise. Having internal walls (septae) within the nozzle, such as would be required for structural support or when multiple fan ducts are aggregated, reduced the noise of the rectangular jet, but could produce a highly directional shedding tone from the septae trailing edges. Finally, a nozzle with both septae and a beveled nozzle, representative of the exhaust system envisioned for a distributed electric propulsion aircraft with a common rectangular duct, produced almost as much noise as the beveled nozzle, with the septae not contributing much reduction in noise.

  14. Use of a variable exposure photographic pyrometer to measure surface temperatures on a hemispherical-face model

    NASA Technical Reports Server (NTRS)

    Kantsios, A. G.; Henley, W. C., Jr.; Snow, W. L.

    1982-01-01

    The use of a photographic pyrometer for nonintrusive measurement of high temperature surfaces in a wind tunnel test is described. The advantages of the pyrometer for measuring surfaces whose unique shape makes use of thermocouples difficult are pointed out. The use of computer operated densitometers or optical processors for the data reduction is recommended.

  15. A preliminary industrial evaluation of the fluidic capillary pyrometer

    NASA Astrophysics Data System (ADS)

    Phillippi, R. M.; Negas, T.

    This paper presents results from a preliminary field evaluation of the fluidic capillary pyrometer (FCP). The device uses a viscosity and, hence, temperature-sensitive fluid resistor, or capillary tube as the sensing element in a simple fluid resistor bridge. Resultant pressure changes due to temperature (typically quite small for a gas) are then amplified to a useful level with fluidic laminar pressure amplifiers. Evaluation has shown over 2000 hours of operation, accumulated by two FCP units in a U.S. Army rotary hearth forging furnace (1200 C) with sensing probes of alumina operating on air. In addition, FCP transient response to flame light-off in a Naval steam generator is discussed. Laboratory calibrations (P-temperature) are shown to 1500 C. Finally, experimental data are given for operation in molten gray iron. Four separate immersions of a single probe for up to 6 hours of total operation have been demonstrated by using a refractory metal (molybdenum) sensing probe coated with a graded cermet-oxide ceramic coating. Nitrogen was used as the working fluid to prevent internal oxidation of the probe. Design considerations for high temperature probes are outlined and corresponding fluidic circuitry is shown.

  16. In-flight particle pyrometer for thermal spray processes. Final report, October 1, 1992--December 31, 1994

    SciTech Connect

    1995-02-20

    The objective of the project was to produce an industrial hardened particle temperature sensor. In general the thermal spray community believes that the particle temperature and velocity prior to impact on the substrate are two of the predominant parameters which effect coating quality. Prior to the full scale prototyping of such an instrument it was necessary to firmly establish the relationship between operating parameters, particle temperature and coating characteristics. It was shown in the first year of this project that the characteristics and consistency of the coatings formed are directly determined by particle velocity and temperature at impact. For the HVOF spray process the authors have also shown that the particle velocity is determined primarily by chamber pressure, while stoichiometry (the ratio of oxygen to fuel) has a minor influence. Hence, particle velocity can be controlled by maintaining the chamber pressure at a set point. Particle temperature, on the other hand is primarily a function of stoichiometry. Therefore particle velocity and temperature can be independently controlled. In the second year (FY-94), an industrial hardened prototype particle temperature sensor (In-flight Particle Pyrometer) was produced. The IPP is a two-color radiation pyrometer incorporating improvements which make the device applicable to the measurement of in-flight temperature of particles over a wide range of operating conditions in thermal spray processes. The device is insensitive to particulate loading (particle feed rate), particle composition, particle size distribution, and provides an ensemble average particle temperature. The sensor head is compact and coupled to the electronics via a fiber optic cable. Fiber optic coupling allows maximum flexibility of deployment while providing isolation of the electronics from electromagnetic interference and the hot, particulate laden environment of a typical spray booth. The device is applicable to all thermal spray processes, including plasma spray, HVOF, twin wire arc, and liquid metal fed processes, as well as other more conventional high temperature processes such as crucible or hearth melting.

  17. Multi-spectral pyrometer for narrow space with high ambient temperature

    NASA Astrophysics Data System (ADS)

    Gao, Shan; Wang, Lixin; Feng, Chi; Xiao, Yihan; Daniel, Ketui

    2015-08-01

    A fiber-optic multi-spectral pyrometer with high spatial and temporal resolution has been applied to measure temperatures of the range from 700 to 1200 K. In a narrow space, the important problems in temperature measurement include the unknown emissivity on target surface and the thermal radiation from the high ambient temperature. This paper analyzed several critical issues affecting the multi-spectral pyrometer and calculated the corresponding model through genetic algorithm. The experiment result showed that this method has high accuracy and the measurement error is 0.44 %.

  18. Multi-channel optical pyrometer for sub-nanosecond temperature measurements at NDCX-I/II

    SciTech Connect

    Ni, P.A.; Bieniosek, F.M.; Waldron, W.L.

    2011-04-13

    We present a detailed technical description of a fast multi-channel pyrometer designed for warm-dense-matter (WDM) experiments with intense heavy ion beams at the neutralized-drift-compression-experiment linear accelerator (NDCX-I/II) at Lawrence Berkeley National Laboratory (LBNL). The unique features of the described instrument are its sub-nanosecond temporal resolution (100 ps rise-time) and a broad range, 1,500 K - 12,000 K of measurable brightness temperatures in the visible and near-infrared regions of the spectrum. The working scheme, calibration procedure, experimental data obtained with the pyrometer and future applications are presented.

  19. Pitch attitude stabilization system utilizing engine pressure ratio feedback signals

    NASA Technical Reports Server (NTRS)

    Kelley, W. W. (inventor)

    1981-01-01

    The changes in the engine pressure ratio signals which result from thrust changes are used to generate a pitch stabilization signal. The signal is combined with other pitch control signals to automatically counteract pitching moments resulting from the changes in engine thrust.

  20. Surface heat flux data from energy balance Bowen ratio systems

    SciTech Connect

    Wesely, M.L.; Cook, D.R.; Coulter, R.L.

    1995-06-01

    The 350 {times} 400 km domain of the Atmospheric Radiation Measurement (ARM) Program`s Clouds and Radiation Testbed (CART) site in the southern Great Plains is equipped with 10 energy balance Bowen ratio (EBBR) stations at grassland sites; they measure the net radiation, ground heat flux, and temperature/humidity differences between 1.0 and 2.0 m heights. The latter differences provide estimates of the geometric Bowen ratio ({beta}), which are used to estimate sensible and latent heat fluxes. This paper addresses the problem that occurs when the value of {beta} is near {minus}1 and to demonstrate the effectiveness of the EBBR stations in collecting energy flux data at the CART site.

  1. Control system and method for a power delivery system having a continuously variable ratio transmission

    DOEpatents

    Frank, A.A.

    1984-07-10

    A control system and method for a power delivery system, such as in an automotive vehicle, having an engine coupled to a continuously variable ratio transmission (CVT). Totally independent control of engine and transmission enable the engine to precisely follow a desired operating characteristic, such as the ideal operating line for minimum fuel consumption. CVT ratio is controlled as a function of commanded power or torque and measured load, while engine fuel requirements (e.g., throttle position) are strictly a function of measured engine speed. Fuel requirements are therefore precisely adjusted in accordance with the ideal characteristic for any load placed on the engine. 4 figs.

  2. Control system and method for a power delivery system having a continuously variable ratio transmission

    DOEpatents

    Frank, Andrew A. (1034 Hillside Ave., Madison, WI 53705)

    1984-01-01

    A control system and method for a power delivery system, such as in an automotive vehicle, having an engine coupled to a continuously variable ratio transmission (CVT). Totally independent control of engine and transmission enable the engine to precisely follow a desired operating characteristic, such as the ideal operating line for minimum fuel consumption. CVT ratio is controlled as a function of commanded power or torque and measured load, while engine fuel requirements (e.g., throttle position) are strictly a function of measured engine speed. Fuel requirements are therefore precisely adjusted in accordance with the ideal characteristic for any load placed on the engine.

  3. Seven-wavelength pyrometer for determining surface temperature of ablation materials

    NASA Technical Reports Server (NTRS)

    Yi, H.

    1985-01-01

    Results which were achieved by a seven-wavelength pyrometer last year are reported in this paper. These studies are directed toward the development of a method for determining the real surface temperature of thermal protection materials and for evaluating its emittance under varieties of reentry environment. A description of the data processing method and apparatus is also included.

  4. Fast six-channel pyrometer for warm-dense-matter experiments with intense heavy-ion beams

    SciTech Connect

    Ni, P.A.; Kulish, M.I.; Mintsev, V.; Nikolaev, D.N.; Ternovoi, V.Ya.; Hoffmann, D.H.H.; Udrea, S.; Tahir, N.A.; Varentsov, D.; Hug, A.

    2008-12-01

    This paper describes a fast multi-channel radiation pyrometer that was developed for warmdense-matter experiments with intense heavy ion beams at Gesellschaft fur Schwerionenforschung mbH (GSI). The pyrometer is capable of measuring of brightness temperatures from 2000 K to 50000 K, at 6 wavelengths in visible and near-infrared parts of spectrum, with 5 nanosecond temporal resolution and several micrometers spatial resolution. The pyrometer's spectral discrimination technique is based on interference filters, which act as filters and mirrors to allow for simultaneous spectral discrimination of the same ray at multiple wavelengths.

  5. An identification method for damping ratio in rotor systems

    NASA Astrophysics Data System (ADS)

    Wang, Weimin; Li, Qihang; Gao, Jinji; Yao, Jianfei; Allaire, Paul

    2016-02-01

    Centrifugal compressor testing with magnetic bearing excitations is the last step to assure the compressor rotordynamic stability in the designed operating conditions. To meet the challenges of stability evaluation, a new method combining the rational polynomials method (RPM) with the weighted instrumental variables (WIV) estimator to fit the directional frequency response function (dFRF) is presented. Numerical simulation results show that the method suggested in this paper can identify the damping ratio of the first forward and backward modes with high accuracy, even in a severe noise environment. Experimental tests were conducted to study the effect of different bearing configurations on the stability of rotor. Furthermore, two example centrifugal compressors (a nine-stage straight-through and a six-stage back-to-back) were employed to verify the feasibility of identification method in industrial configurations as well.

  6. Short wavelengths active bichromatic pulsed pyrometer for solids and liquids designed for measurements in harsh environments

    NASA Astrophysics Data System (ADS)

    Navello, L.; Lebedinsky, J.; Offret, J. P.; Serio, B.; Davin, T.; Bailly, Y.; Herv, P.

    2015-05-01

    Optical passive methods for temperature measurements such as thermography or optical pyrometry are very interesting because they allow a non-intrusive measurement when the emissivity is known. The knowledge of this coefficient is critical for determining the actual temperature of a surface from the thermal radiation emitted in a wavelength band. The bichromatic pulsed pyrometer allows to overcome the knowledge of this parameter provided that precautions are taken in the choice of the values of wavelengths. When the object to be measured is placed in harsh environments, such passive optical methods are greatly disturbed by the presence of an optically absorbing medium. They are also distorted when the measured objects are located in very hot environments emitting intense disturbing radiation. In this study, we present an active bichromatic radiometric method for measuring the temperature of a surface in harsh environments. The method is based on a localized excitation by a modulated laser source in the infrared range. Detecting the temperature modulation, which is correlated with the excitation, is performed using a lock-in amplifier able to extract the signal embedded in a noise up to a million times superior. Working at short wavelengths (visible range and near infrared range) offers a large dynamic range and minimizes the error due to variations in emissivity with the wavelength. This system collects the radiation emitted by the object at a distance from a few meters up to dozens of meters depending on the configuration of the optical system. Both the principle and the design of the active bichromatic optical surface thermometer are presented and discussed. To demonstrate the method, results obtained on a molten ceramic stream are presented.

  7. A sensitive time-resolved radiation pyrometer for shock-temperature measurements above 1500 K

    SciTech Connect

    Boslough, M.B. ); Ahrens, T.J. )

    1989-12-01

    An optical system has been developed which can determine time-resolved temperatures in shocked materials by measuring the spectral radiance of light emitted from shocked solid samples in the visible and near-infrared wavelength range (0.5--1.0 {mu}m). It can measure temperatures as low as 1500 K and has been successfully used to observe shock-induced chemical reactions in powder samples. The high sensitivity of this radiation pyrometer can be attributed to the large angular aperture (0.06 sr), the large bandwidth per channel (up to 0.1 {mu}m), the large photodiode detection areas (1.0 cm{sup 2} ), and the small number of calibrated channels (4) among which light is divided. Improved calibration techniques, as well as the layout of the instrument, eliminate certain sources of error encountered in previous shock-temperature experiments. Errors in the measured spectral radiance were reduced by: (1) recalibration before every experiment to account for changes in optical components; (2) direct calibration of voltage recorded at each digitizer to prevent transfer error by an intermediate step; (3) use of a spectral irradiance calibration lamp to exclude errors due to spatial inhomogeneities associated with spectral radiance sources; and (4) obtaining a large spatial average of light at each wavelength from the same portion of the sample to eliminate errors from possible inhomogeneities in the sample. The magnitude each of these errors could previously contribute was 1%--2% of the total signal. Absolute temperature uncertainties, determined from the standard deviation of the measured spectral radiances from the least-squares-fit values, are typically about 5%. Emissivities are poorly constrained by spectral radiance data because of a weak functional dependence, and uncertainties can easily exceed 50% for temperatures of around 2000 K.

  8. Evaluation and improvement in the accuracy of a charge-coupled-device-based pyrometer for temperature field measurements of continuous casting billets.

    PubMed

    Bai, Haicheng; Xie, Zhi; Zhang, Yuzhong; Hu, Zhenwei

    2013-06-01

    This paper presents a radiometric high-temperature field measurement model based on a charge-coupled-device (CCD). According to the model, an intelligent CCD pyrometer with a digital signal processor as the core is developed and its non-uniformity correction algorithm for reducing the differences in accuracy between individual pixel sensors is established. By means of self-adaptive adjustment for the light-integration time, the dynamic range of the CCD is extended and its accuracy in low-temperature range is improved. The non-uniformity correction algorithm effectively reduces the accuracy differences between different pixel sensors. The performance of the system is evaluated through a blackbody furnace and an integrating sphere, the results of which show that the dynamic range of 400 K is obtained and the accuracy in low temperature range is increased by 7 times compared with the traditional method based on the fixed light-integration time. In addition, the differences of accuracy between the on-axis pixel and the most peripheral pixels are decreased from 19.1 K to 2.8 K. Therefore, this CCD pyrometer ensures that the measuring results of all pixels tend to be equal-accuracy distribution across the entire measuring ranges. This pyrometric system has been successfully applied to the temperature field measurements in continuous casting billets. PMID:23822369

  9. 21 CFR 862.1455 - Lecithin/sphingomyelin ratio in amniotic fluid test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems 862.1455 Lecithin/sphingomyelin ratio in amniotic fluid test system....

  10. 21 CFR 862.1455 - Lecithin/sphingomyelin ratio in amniotic fluid test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862.1455 Lecithin/sphingomyelin ratio in amniotic fluid test system....

  11. 21 CFR 862.1455 - Lecithin/sphingomyelin ratio in amniotic fluid test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems 862.1455 Lecithin/sphingomyelin ratio in amniotic fluid test system....

  12. 21 CFR 862.1455 - Lecithin/sphingomyelin ratio in amniotic fluid test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems 862.1455 Lecithin/sphingomyelin ratio in amniotic fluid test system....

  13. Pyrometer mount for a closed-circuit thermal medium cooled gas turbine

    DOEpatents

    Jones, Raymond Joseph (Duanesburg, NY); Kirkpatrick, Francis Lawrence (late of Galway, NY); Burns, James Lee (Schenectady, NY); Fulton, John Robert (Clifton Park, NY)

    2002-01-01

    A steam-cooled second-stage nozzle segment has an outer band and an outer cover defining a plenum therebetween for receiving cooling steam for flow through the nozzles to the inner band and cover therefor and return flow through the nozzles. To measure the temperature of the buckets of the stage forwardly of the nozzle stage, a pyrometer boss is electron beam-welded in an opening through the outer band and TIG-welded to the outer cover plate. By machining a hole through the boss and seating a linearly extending tube in the boss, a line of sight between a pyrometer mounted on the turbine frame and the buckets is provided whereby the temperature of the buckets can be ascertained. The welding of the boss to the outer band and outer cover enables steam flow through the plenum without leakage, while providing a line of sight through the outer cover and outer band to measure bucket temperature.

  14. Temperature measurement involving nanostructured thermal barrier coating using a multiwavelength pyrometer

    NASA Technical Reports Server (NTRS)

    Ng, Daniel

    1996-01-01

    It has been reported that erroneous results were obtained when a conventional pyrometer was used to measure the surface temperature of turbine engine components. Temperatures discrepancies were observed in components which were identical, except that one had its measured surface covered by a nanostructured thermal barrier coating (TBC) whereas the other component's surface was not so coated. These components were placed in an identical environment, receiving identical heat fluxes. A pyrometer measured the TBC covered surface hundreds degrees lower. These coatings were about 25 (mu)m thick, consisting of hundreds of layers of finer structures. The TBC's had very low thermal conductivity, heat flux calculations indicated that the temperatures of the coated surface should exhibit much higher temperature than the uncoated surface. Because these coatings were transparent to radiation from the visible to the infrared region, the temperatures measured by the pyrometer should be the temperature of the covered surface. Turbo components' performance and service life depend critically on the temperatures that it would experience; it is therefore important to know accurately and confidently the real surface temperature. Out of these concerns, an investigation into the measurement of nanostructured material surface temperature was carried out.

  15. Near-infrared two-color pyrometer for determining ignition temperatures of metals and metal alloys

    NASA Technical Reports Server (NTRS)

    Nguyen, K.; Branch, M. C.

    1985-01-01

    A two-color pyrometer has been designed, constructed, and used to measure the ignition temperatures of metals and metal alloys. Cylindrical metal and metal alloy specimens were ignited by a focused cw CO2 laser beam in a cool, static, pure oxygen environment. The pyrometer operates in the near-infrared at two narrow spectral regions, with a nominal bandwidth of 10 nm centered at 0.9051 and 1.06 micron, and has a temperature range from 1000 to 4000 K. In the present design the temperature of a spot, about 0.5 mm in diameter, can be recorded with a maximum time resolution of 25 microseconds and with an accuracy of a few percent. Results of CO2 laser ignition of cylindrical specimens of 6061 aluminum alloy and 302 SS in a pure oxygen environment were obtained from the two-color pyrometer and were compared with those obtained from a thermocouple placed inside the specimen near the laser-irradiated surface.

  16. Two-Step Calibration of a Multiwavelength Pyrometer for High Temperature Measurement Using a Quartz Lamp

    NASA Technical Reports Server (NTRS)

    Ng, Daniel

    2001-01-01

    There is no theoretical upper temperature limit for pyrometer application in temperature measurements. NASA Glenn's multiwavelength pyrometer can make measurements over wide temperature ranges. However, the radiation spectral response of the pyrometer's detector must be calibrated before any temperature measurement is attempted, and it is recommended that calibration be done at temperatures close to those for which measurements will be made. Calibration is a determination of the constants of proportionality at all wavelengths between the detector's output (voltage) and its input signals (usually from a blackbody radiation source) in order to convert detector output into radiation intensity. To measure high temperatures, the detectors are chosen to be sensitive in the spectral range from 0.4 to 2.5 micrometers. A blackbody furnace equilibrated at around 1000 C is often used for this calibration. Though the detector may respond sensitively to short wavelengths radiation, a blackbody furnace at 1000 C emits only feebly at very short wavelengths. As a consequence, the calibration constants that result may not be the most accurate. For pyrometry calibration, a radiation source emitting strongly at the short wavelengths is preferred. We have chosen a quartz halogen lamp for this purpose.

  17. Mortality, fertility, and the OY ratio in a model hunter-gatherer system.

    PubMed

    White, Andrew A

    2014-06-01

    An agent-based model (ABM) is used to explore how the ratio of old to young adults (the OY ratio) in a sample of dead individuals is related to aspects of mortality, fertility, and longevity experienced by the living population from which the sample was drawn. The ABM features representations of rules, behaviors, and constraints that affect person- and household-level decisions about marriage, reproduction, and infant mortality in hunter-gatherer systems. The demographic characteristics of the larger model system emerge through human-level interactions playing out in the context of "global" parameters that can be adjusted to produce a range of mortality and fertility conditions. Model data show a relationship between the OY ratios of living populations (the living OY ratio) and assemblages of dead individuals drawn from those populations (the dead OY ratio) that is consistent with that from empirically known ethnographic hunter-gatherer cases. The dead OY ratio is clearly related to the mean ages, mean adult mortality rates, and mean total fertility rates experienced by living populations in the model. Sample size exerts a strong effect on the accuracy with which the calculated dead OY ratio reflects the actual dead OY ratio of the complete assemblage. These results demonstrate that the dead OY ratio is a potentially useful metric for paleodemographic analysis of changes in mortality and mean age, and suggest that, in general, hunter-gatherer populations with higher mortality, higher fertility, and lower mean ages are characterized by lower dead OY ratios. PMID:24523247

  18. Overall payload ratio of a combined laser and chemical propulsion system for geo launch

    NASA Astrophysics Data System (ADS)

    Hong, Zuu-Chang; Liu, Jia Ming; Chern, Jeng-Shing

    2002-04-01

    This paper gives a discussion about the overall payload ratio of solid-rocket-booster-assisted laser propulsion system for geosynchronous earth orbit payload launch. When the ground station can provide the required peak laser power, we can obtain the maximum payload ratio (ratio of final mass to initial mass). Now, if the peak laser power is limited to a lower level, the payload ratio which can be obtained will also be lower. When the peak laser power that can be provided is too low, the thrust-to-weight ratio will be <1 at the initial phase of the launch. In order to keep the performance of the launching system, we use a strap-on solid-rocket-booster to compensate the system for thrust loss. It is found that the penalty can be reduced significantly.

  19. The linear system theory's account of behavior maintained by variable-ratio schedules.

    PubMed

    McDowell, J J; Wixted, J T

    1988-01-01

    The mathematical theory of linear systems, which has been used successfully to describe behavior maintained by variable-interval schedules, is extended to describe behavior maintained by variable-ratio schedules. The result of the analysis is a pair of equations, one of which expresses response rate on a variable-ratio schedule as a function of the mean ratio requirement (n) that the schedule arranges. The other equation expresses response rate on a variable-ratio schedule as a function of reinforcement rate. Both equations accurately describe existing data from variable-ratio schedules. The theory accounts for two additional characteristics of behavior maintained by variable-ratio schedules; namely, the appearance of strained, two-valued (i.e., zero or very rapid) responding at large ns, and the abrupt cessation of responding at a boundary n. The theory also accounts for differences between behavior on variable-interval and variable-ratio schedules, including (a) the occurrence of strained responding on variable-ratio but not on variable-interval schedules, (b) the abrupt cessation of responding on occurrence of higher response rates on variable-ratio than on variable-interval schedules. Furthermore, given data from a series of variable-interval schedules and from a series of concurrent variable-ratio variable-interval schedules, the theory permits quantitative prediction of many properties of behavior on single-alternative variable-ratio schedules. The linear system theory's combined account of behavior on variable-interval and variable-ratio schedules is superior to existing versions of six other mathematical theories of variable-interval and variable-ratio responding. PMID:3279150

  20. Influence of Ventilation Ratio on Desiccant Air Conditioning System's Efficiency Performance

    NASA Astrophysics Data System (ADS)

    Tran, Thien Nha; Akisawa, Atsushi; Kashiwagi, Takao; Hamamoto, Yoshinori

    Ventilation air is a concern for engineers since ventilated air controls indoor air contamination; additional ventilation, however, increases the energy consumption of buildings. The study investigates the energy efficiency performance of the desiccant dehumidification air conditioning system in the context of ventilation for a hot-humid climate such as summer in Japan. The investigation focuses on the variable ratio of ventilation air as required by the application of air conditioning system. The COP of the desiccant air conditioning system is determined. The evaluation is subsequently performed by comparing the desiccant based system with the conventional absorption cooling system and the vapor compression cooling system. Based on 12 desiccant rotor simulations, it is found that the desiccant regeneration temperature required varies between 47°C to 85°C as ventilation ratio increases from 0. 0 to 100%, and up to 52. 5°C as the ventilation ratio achieves 14%. The heat required for regenerating desiccant accounts for 55% and higher of the system's total heat consumption; the system is expected to be energy efficient by using wasted heat from the absorption chiller for desiccant regeneration; and its energy efficiency expands as the ratio of ventilation air rises above 15% compared with the conventional absorption cooling system. The energy efficiency also benefits as the ratio rises beyond 70% against the conventional vapor compression cooling system.

  1. Temporal trends in nitrogen isotope ratios of winter flounder collected from Rhode Island coastal systems

    EPA Science Inventory

    Nitrogen isotope ratios (15N) were measured in muscle tissue of juvenile winter flounder, Pseudopleuronectes americanus, collected from several estuarine systems along the coast of Rhode Island, USA, including Narragansett Bay, Narrow River and three coastal lagoons. Fish collect...

  2. High contrast ratio and compact-sized prism for DLP projection system.

    PubMed

    Huang, Yung-Chih; Pan, Jui-Wen

    2014-07-14

    In this paper, a novel light separator with contrast ratio enhancement but maintaining the optical efficiency of the DLP projection system is proposed. The main capability of the novel light separator is to direct the uncontrolled light away from the image system. The working theorem for the novel light separator is derived as well. Uncontrolled light is kept away from the image system by a total internal reflection surface, thereby effectively improving the image quality. Compared with the conventional contrast ratio enhancement method, the FO:FO contrast ratio can be improved from 839:1 to 48250:1, the ANSI contrast ratio can be improved from 180:1 to 306:1, while the image system efficiency remains at 76.2%. PMID:25090516

  3. A high S/N ratio spin flip chopper system for a pulsed neutron source

    NASA Astrophysics Data System (ADS)

    Taketani, K.; Ebisawa, T.; Hino, M.; Hirota, K.; Ino, T.; Kitaguchi, M.; Mishima, K.; Muto, S.; Oide, H.; Oku, T.; Otono, H.; Sakai, K.; Shima, T.; Shimizu, H. M.; Yamashita, S.; Yoshioka, T.

    2011-04-01

    We report a successful demonstration of a high S/N ratio spin flip chopper (SFC) system for pulsed neutron sources. The system consists of two SFCs and each SFC consists of a radio frequency (RF) flipper and Soller magnetic supermirrors. The aperture of the Soller mirror was 18 mm in width and 20 mm in height. The S/N ratio of the system was 306:1. This system is going to be installed to measure neutron lifetime precisely using the cold-neutron beam line, BL05 polarized-beam branch, at the Materials and Life Science Experimental Facility (MLF) in Japan Proton Accelerator Research Complex (J-PARC).

  4. Design and fabrication of an infrared optical pyrometer ASIC as a diagnostic for shock physics experiments

    NASA Astrophysics Data System (ADS)

    Gordon, Jared

    Optical pyrometry is the sensing of thermal radiation emitted from an object using a photoconductive device to convert photons into electrons, and is an important diagnostic tool in shock physics experiments. Data obtained from an optical pyrometer can be used to generate a blackbody curve of the material prior to and after being shocked by a high speed projectile. The sensing element consists of an InGaAs photodiode array, biasing circuitry, and multiple transimpedance amplifiers to boost the weak photocurrent from the noisy dark current into a signal that can eventually be digitized. Once the circuit elements have been defined, more often than not commercial-off-the-shelf (COTS) components are inadequate to satisfy every requirement for the diagnostic, and therefore a custom application specific design has to be considered. This thesis outlines the initial challenges with integrating the photodiode array block with multiple COTS transimpedance amplifiers onto a single chip, and offers a solution to a comparable optical pyrometer that uses the same type of photodiodes in conjunction with a re-designed transimpedance amplifier integrated onto a single chip. The final design includes a thorough analysis of the transimpedance amplifier along with modeling the circuit behavior which entails schematics, simulations, and layout. An alternative circuit is also investigated that incorporates an approach to multiplex the signals from each photodiode onto one data line and not only increases the viable real estate on the chip, but also improves the behavior of the photodiodes as they are subjected to less thermal load. The optical pyrometer application specific integrated circuit (ASIC) for shock physic experiments includes a transimpedance amplifier (TIA) with a 100 k? gain operating at bandwidth of 30 MHz, and an input-referred noise RMS current of 50 nA that is capable of driving a 50 ? load.

  5. A system for estimating bowen ratio And evaporation from waste lagoons

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A low cost system was deployed above a swine waste lagoon to obtain estimates of Bowen ratios and characterize lagoon temperatures. The system consisted of humidity and temperature sensors and anemometers deployed above the lagoon, water temperature sensors, and a meteorological station located by t...

  6. The Determination of Heat Capacity Ratios in a Simple Open System

    ERIC Educational Resources Information Center

    Holden, Glen L.

    2007-01-01

    A virtually closed system is treated as open and compared to known results. The classic experiment of Clement and Desormes provides the conceptual framework for this open system approach in determining the molar heat capacity ratios, lambda. This alternate view, extends the theoretical treatment beyond the first law of thermodynamics for closed

  7. The Determination of Heat Capacity Ratios in a Simple Open System

    ERIC Educational Resources Information Center

    Holden, Glen L.

    2007-01-01

    A virtually closed system is treated as open and compared to known results. The classic experiment of Clement and Desormes provides the conceptual framework for this open system approach in determining the molar heat capacity ratios, lambda. This alternate view, extends the theoretical treatment beyond the first law of thermodynamics for closed…

  8. Carbon and nitrogen isotope ratios of juvenile winter flounder as indicators of inputs to estuarine systems

    EPA Science Inventory

    Stable carbon and nitrogen isotope ratios were measured in the muscle tissues of young-of-the-year (YOY) winter flounder, Pseudopleuronectes americanus, collected from several estuarine systems along the coast of Rhode Island, USA. These systems included three coastal lagoons (Ni...

  9. Remote Heat Flux Using a Self Calibration Multiwavelength Pyrometer and a Transparent Material

    NASA Technical Reports Server (NTRS)

    Ng, Daniel

    1998-01-01

    A self calibrating multiwavelength pyrometer was used to conduct remote heat flux measurements using a transparent sapphire disk by determining the sapphire disk's front and back surface temperatures. Front surface temperature (Tfs) was obtained from detection of surface emitted radiation at long wavelengths (k = 6 gm). Back surface temperature (Tbs) was obtained from short wavelength (1 to 5 gm) radiation transmitted through the sapphire disk. The thermal conductivity of the sapphire disk and the heat transfer coefficients h, and h2 of its surfaces are determined experimentally. An analysis of the heat flux measurement is presented.

  10. Remote Heat Flux Measurement Using a Self Calibration Multiwavelength Pyrometer and a Transparent Material

    NASA Technical Reports Server (NTRS)

    Ng, Daniel

    1998-01-01

    A self calibrating multiwavelength pyrometer was used to conduct remote heat flux measurements using a transparent sapphire disk by determining the sapphire disk's front and back surface temperatures. Front surface temperature (Tfs) was obtained from detection of surface emitted radiation at long wavelengths (lambda > 6 micrometers). Back surface temperature (Tbs) was obtained from short wavelength (1 to 5 micrometers) radiation transmitted through the sapphire disk. The thermal conductivity k of the sapphire disk and the heat transfer coefficients h(sub 1) and h(sub 2) of its surfaces are determined experimentally. An analysis of the heat flux measurement is presented.

  11. Application of Taguchi methods to dual mixture ratio propulsion system optimization for SSTO vehicles

    NASA Technical Reports Server (NTRS)

    Stanley, Douglas O.; Unal, Resit; Joyner, C. R.

    1992-01-01

    The application of advanced technologies to future launch vehicle designs would allow the introduction of a rocket-powered, single-stage-to-orbit (SSTO) launch system early in the next century. For a selected SSTO concept, a dual mixture ratio, staged combustion cycle engine that employs a number of innovative technologies was selected as the baseline propulsion system. A series of parametric trade studies are presented to optimize both a dual mixture ratio engine and a single mixture ratio engine of similar design and technology level. The effect of varying lift-off thrust-to-weight ratio, engine mode transition Mach number, mixture ratios, area ratios, and chamber pressure values on overall vehicle weight is examined. The sensitivity of the advanced SSTO vehicle to variations in each of these parameters is presented, taking into account the interaction of each of the parameters with each other. This parametric optimization and sensitivity study employs a Taguchi design method. The Taguchi method is an efficient approach for determining near-optimum design parameters using orthogonal matrices from design of experiments (DOE) theory. Using orthogonal matrices significantly reduces the number of experimental configurations to be studied. The effectiveness and limitations of the Taguchi method for propulsion/vehicle optimization studies as compared to traditional single-variable parametric trade studies is also discussed.

  12. Development of a System to Measure Recrystallization Ratio of Plate Steel Using Laser-Based Ultrasonics

    SciTech Connect

    Nagata, Y.; Yamada, H.; Hamada, N.; Lim, C. S.; Yi, J. K.; Hong, S. T.; Choi, S. G.; Oh, K. J.

    2007-03-21

    In this study, a material property measurement system of plate steel using laser-based ultrasonics has been developed. The system consists of pulsed Nd:YAG laser for ultrasonic generation, CW single frequency laser and Fabry-Perot interferometer for ultrasonic detection. The system generates and detects shear waves and precisely calculates anisotropy parameter values of shear wave velocities of test samples. At first, the relationship between anisotropy parameter and recrystallization ratio was investigated in the laboratory experiments. Quenching the test samples just after the ultrasonic measurement, recrystallization ratio values were measured by the conventional microscopic method. According to the experimental results, the anisotropy parameter values showed a good correlation with actual recrystallization ratio values. To evaluate the applicability of the system to real steel production line, the system was installed in hot rolling pilot plant of plate steel. As the results, it was demonstrated that the system could measure the recrystallization ratio using the anisotropy parameter values of shear wave velocities, even in the environment of hot rolling pilot plant.

  13. Radiation pyrometer for gas turbine blades. [in LOX turbopump engine

    NASA Technical Reports Server (NTRS)

    Rohy, D. A.; Compton, W. A.

    1973-01-01

    A turbine blade temperature measuring system for liquid oxygen turbopumps is reported. The system includes a three mode, two-input optical signal processor, interconnecting cable, and four sensor heads. Two of the heads are aperture type, while the other two are lens type. This system is applicable to a temperature range of 1400 to 2200 F.

  14. Improvement of signal-to-interference ratio and signal-to-noise ratio in nerve cuff electrode systems.

    PubMed

    Chu, Jun-Uk; Song, Kang-Il; Han, Sungmin; Lee, Soo Hyun; Kim, Jinseok; Kang, Ji Yoon; Hwang, Dosik; Suh, Jun-Kyo Francis; Choi, Kuiwon; Youn, Inchan

    2012-06-01

    Cuff electrodes are effective for chronic electroneurogram (ENG) recording while minimizing nerve damage. However, the ENG signals are usually contaminated by electromyogram (EMG) activity from the surrounding muscles, stimulus artifacts produced by the electrical stimulation and noise generated in the first stage of the neural signal amplifier. This paper proposed a new cuff electrode to reduce the interference from EMG signals and stimulus artifacts. As a result, when an additional middle electrode was placed at the center of the cuff electrode, a significant improvement in the signal-to-interference ratio was achieved at 11% for the EMG signals and 12% for the stimulus artifacts when compared to a conventional tripolar cuff. Furthermore, a new low-noise amplifier was proposed to improve the signal-to-noise ratio. The circuit was designed based on a noise analysis to minimize the noise, and the results show that the total noise of the amplifier was below 1??V for a cuff impedance of 1 k? and a frequency bandwidth of 300 to 5000 Hz. PMID:22551721

  15. Disturbance rejection performance analyses of closed loop control systems by reference to disturbance ratio.

    PubMed

    Alagoz, Baris Baykant; Deniz, Furkan Nur; Keles, Cemal; Tan, Nusret

    2015-03-01

    This study investigates disturbance rejection capacity of closed loop control systems by means of reference to disturbance ratio (RDR). The RDR analysis calculates the ratio of reference signal energy to disturbance signal energy at the system output and provides a quantitative evaluation of disturbance rejection performance of control systems on the bases of communication channel limitations. Essentially, RDR provides a straightforward analytical method for the comparison and improvement of implicit disturbance rejection capacity of closed loop control systems. Theoretical analyses demonstrate us that RDR of the negative feedback closed loop control systems are determined by energy spectral density of controller transfer function. In this manner, authors derived design criteria for specifications of disturbance rejection performances of PID and fractional order PID (FOPID) controller structures. RDR spectra are calculated for investigation of frequency dependence of disturbance rejection capacity and spectral RDR analyses are carried out for PID and FOPID controllers. For the validation of theoretical results, simulation examples are presented. PMID:25311160

  16. Calibration of fiber-optic shock pyrometer using high-power coiled tungsten lamp

    NASA Astrophysics Data System (ADS)

    Fat'yanov, O. V.; Asimow, P. D.

    2015-06-01

    Comparison of all known calibration sources indicates that coiled standards of spectral irradiance, despite their very non-uniform brightness, are currently the best practical choice for accurate shock temperature measurements above 3000 K by optical pyrometry. We review all three documented methods of shock pyrometer calibration to a coiled lamp and show that only one technique, with no fiber-optics employed, is free of major radiometric errors. We report the development of a new, accurate to 5% and precise to 1-1.5% calibration procedure for the modified Caltech 6-channel, 3-ns temporal resolution combined open beam and fiber-coupled instrument. A designated central area of an 0.7x demagnified image of 900 W coiled-coil lamp filament is used, cross-calibrated against a NIST-traceable tungsten ribbon lamp. The results of two slightly different cross-calibrations are reported and the procedure to characterize the difference between the static and dynamic response of NewFocus 1801 amplified photodetectors. The most essential requirements for error-free calibration of a fiber-optic pyrometer using a coiled irradiance standard lamp are discussed. All these conditions are validated in actual radiometric tests and shock temperature experiments on single-crystal NaCl and MgO.

  17. Measurements on flame temperature and its 3D distribution in a 660 MWe arch-fired coal combustion furnace by visible image processing and verification by using an infrared pyrometer

    NASA Astrophysics Data System (ADS)

    Huajian, Wang; Zhifeng, Huang; Dundun, Wang; Zixue, Luo; Yipeng, Sun; Qingyan, Fang; Chun, Lou; Huaichun, Zhou

    2009-11-01

    In order to verify the 3D temperature distribution of combustion in large-scale, coal-fired boiler furnaces visualized through a visible flame image processing system, a carefully calibrated portable flame temperature measuring system adopting the same flame image processing technique was developed, which is more convenient for industrial flame measurements. Furthermore, the temperatures and emissivities measured by the portable system were compared with the results by an infrared pyrometer which was used to measure the equivalent blackbody temperatures of the flames. The relative differences of the predicted temperatures and emissivity for a blackbody furnace by the portable system are less than 1% and 3%, respectively, showing a good accuracy for its application in the combustion industry. The equivalent blackbody temperatures deduced from the flame temperatures and emissivities measured by the portable system from 12 flame-observing ports in a 660 MWe arch-fired boiler in three horizontal sections at different elevations were compared with those measured by the infrared pyrometer. The relative differences are less than 7%, an acceptable agreement for measurements in the case of a coal-fired furnace. The cross-section-averaged temperatures deduced from the 3D temperature distribution acquired by the visualizing system were verified by those measured by the portable flame measuring system, and the two sets of results matched each other reasonably. This revealed that the coal combustion in the furnace was suffering from seriously delayed ignition of coal, leading to a lower efficiency of fuel utilization.

  18. DISK-PLANETS INTERACTIONS AND THE DIVERSITY OF PERIOD RATIOS IN KEPLER'S MULTI-PLANETARY SYSTEMS

    SciTech Connect

    Baruteau, Clement; Papaloizou, John C. B. E-mail: J.C.B.Papaloizou@damtp.cam.ac.uk

    2013-11-20

    The Kepler mission is dramatically increasing the number of planets known in multi-planetary systems. Many adjacent planets have orbital period ratios near resonant values, with a tendency to be larger than required for exact first-order mean-motion resonances. This feature has been shown to be a natural outcome of orbital circularization of resonant planetary pairs due to star-planet tidal interactions. However, this feature holds in multi-planetary systems with periods longer than 10 days, in which tidal circularization is unlikely to provide efficient divergent evolution of the planets' orbits to explain these orbital period ratios. Gravitational interactions between planets and their parent protoplanetary disk may instead provide efficient divergent evolution. For a planet pair embedded in a disk, we show that interactions between a planet and the wake of its companion can reverse convergent migration and significantly increase the period ratio from a near-resonant value. Divergent evolution due to wake-planet interactions is particularly efficient when at least one of the planets opens a partial gap around its orbit. This mechanism could help account for the diversity of period ratios in Kepler's multiple systems from super-Earth to sub-Jovian planets with periods greater than about 10 days. Diversity is also expected for pairs of planets massive enough to merge their gap. The efficiency of wake-planet interactions is then much reduced, but convergent migration may stall with a variety of period ratios depending on the density structure in the common gap. This is illustrated for the Kepler-46 system, for which we reproduce the period ratio of Kepler-46b and c.

  19. Disk-Planets Interactions and the Diversity of Period Ratios in Kepler's Multi-planetary Systems

    NASA Astrophysics Data System (ADS)

    Baruteau, Clement; Papaloizou, John C. B.

    2013-11-01

    The Kepler mission is dramatically increasing the number of planets known in multi-planetary systems. Many adjacent planets have orbital period ratios near resonant values, with a tendency to be larger than required for exact first-order mean-motion resonances. This feature has been shown to be a natural outcome of orbital circularization of resonant planetary pairs due to star-planet tidal interactions. However, this feature holds in multi-planetary systems with periods longer than 10 days, in which tidal circularization is unlikely to provide efficient divergent evolution of the planets' orbits to explain these orbital period ratios. Gravitational interactions between planets and their parent protoplanetary disk may instead provide efficient divergent evolution. For a planet pair embedded in a disk, we show that interactions between a planet and the wake of its companion can reverse convergent migration and significantly increase the period ratio from a near-resonant value. Divergent evolution due to wake-planet interactions is particularly efficient when at least one of the planets opens a partial gap around its orbit. This mechanism could help account for the diversity of period ratios in Kepler's multiple systems from super-Earth to sub-Jovian planets with periods greater than about 10 days. Diversity is also expected for pairs of planets massive enough to merge their gap. The efficiency of wake-planet interactions is then much reduced, but convergent migration may stall with a variety of period ratios depending on the density structure in the common gap. This is illustrated for the Kepler-46 system, for which we reproduce the period ratio of Kepler-46b and c.

  20. Bionomic Exploitation of a Ratio-Dependent Predator-Prey System

    ERIC Educational Resources Information Center

    Maiti, Alakes; Patra, Bibek; Samanta, G. P.

    2008-01-01

    The present article deals with the problem of combined harvesting of a Michaelis-Menten-type ratio-dependent predator-prey system. The problem of determining the optimal harvest policy is solved by invoking Pontryagin's Maximum Principle. Dynamic optimization of the harvest policy is studied by taking the combined harvest effort as a dynamic

  1. Optimization of Gear Ratio in the Tidal Current Generation System based on Generated Energy

    NASA Astrophysics Data System (ADS)

    Naoi, Kazuhisa; Shiono, Mitsuhiro; Suzuki, Katsuyuki

    It is possible to predict generating power of the tidal current generation, because of the tidal current's periodicity. Tidal current generation is more advantageous than other renewable energy sources, when the tidal current generation system is connected to the power system and operated. In this paper, we propose a method used to optimize the gear ratio and generator capacity, that is fundamental design items in the tidal current generation system which is composed of Darrieus type water turbine and squirrel-cage induction generator coupled with gear. The proposed method is applied to the tidal current generation system including the most large-sized turbine that we have developed and studied. This paper shows optimum gear ratio and generator capacity that make generated energy maximum, and verify effectiveness of the proposed method. The paper also proposes a method of selecting maximum generating current velocity in order to reduce the generator capacity, from the viewpoint of economics.

  2. Aspect-ratio dependence of percolation probability in a rectangular system

    NASA Astrophysics Data System (ADS)

    Tsubakihara, Shinsuke

    2000-12-01

    I investigate site percolation on a rectangular system (aspect ratio a) of a square lattice for a given occupation probability p (not restricted to pc) using computer simulations. The dependence of the percolation probability R on a is shown and analyzed on the basis of a modified finite-size scaling function. A method for evaluating R without statistical simulations is proposed for given conditions (longitudinal dimension L, a, and p) of the system.

  3. Multicanonical Determination of the Symbol Error Ratio of WDM Polarization Multiplexed QPSK Systems

    NASA Astrophysics Data System (ADS)

    Soliman, George; Yevick, David

    2014-12-01

    The multicanonical method is applied to the calculation of the symbol error ratio (SER) as a function of the optical signal to noise ratio (OSNR) at the receiver for a polarization multiplexed quadrature phase shift keying (PM-QPSK) wavelength division multiplexed (WDM) system. We improve upon previous calculations by including polarization mode dispersion (PMD) and subsequently verifying the numerical accuracy of our calculations. Our numerical studies demonstrate that acceptable accuracy can be achieved even when advancing the polarization through the fiber with relatively large propagation step lengths.

  4. Evaluation of denitrification-nitrification biofilter systems in treating wastewater with low carbon: nitrogen ratios.

    PubMed

    Kim, Seungjin; Bae, Wookeun; Kim, Moonil; Kim, Jong-Oh; Chung, Jinwook

    2015-01-01

    A two-stage biological aerated/anoxic filter (BAF) system for denitrification-nitrification was developed to increase nitrogen removal in the treatment of municipal wastewater with low carbon:nitrogen (C/N) ratio [Formula: see text]. This system exhibited a high denitrification efficiency (67%), despite the low C/N ratio, and the ratio of reduced nitrate to consumed organic compounds was greater than the theoretical value due to the minimization of the conversion of organic carbon to biomass growth, the maintenance of low levels of dissolved oxygen in recycled water, and the maximization of use of organic carbon biosorbed inside biomass in the denitrification BAF. The maximum rate of nitrogen removal was achieved at a recycle ratio of 170%, and the headloss in two BAFs was maintained after a 24-h backwash. Biological nitrogen removal in a two-stage BAF system was possible in a short hydraulic retention time (1.2 h) because the maximum reaction rates of nitrifiers and denitrifiers in each column were achieved. PMID:25287910

  5. Influence of tire dynamics on slip ratio estimation of independent driving wheel system

    NASA Astrophysics Data System (ADS)

    Li, Jianqiu; Song, Ziyou; Wei, Yintao; Ouyang, Minggao

    2014-11-01

    The independent driving wheel system, which is composed of in-wheel permanent magnet synchronous motor(I-PMSM) and tire, is more convenient to estimate the slip ratio because the rotary speed of the rotor can be accurately measured. However, the ring speed of the tire ring doesn't equal to the rotor speed considering the tire deformation. For this reason, a deformable tire and a detailed I-PMSM are modeled by using Matlab/Simulink. Moreover, the tire/road contact interface(a slippery road) is accurately described by the non-linear relaxation length-based model and the Magic Formula pragmatic model. Based on the relatively accurate model, the error of slip ratio estimated by the rotor rotary speed is analyzed in both time and frequency domains when a quarter car is started by the I-PMSM with a definite target torque input curve. In addition, the natural frequencies(NFs) of the driving wheel system with variable parameters are illustrated to present the relationship between the slip ratio estimation error and the NF. According to this relationship, a low-pass filter, whose cut-off frequency corresponds to the NF, is proposed to eliminate the error in the estimated slip ratio. The analysis, concerning the effect of the driving wheel parameters and road conditions on slip ratio estimation, shows that the peak estimation error can be reduced up to 75% when the LPF is adopted. The robustness and effectiveness of the LPF are therefore validated. This paper builds up the deformable tire model and the detailed I-PMSM models, and analyzes the effect of the driving wheel parameters and road conditions on slip ratio estimation.

  6. The Minimum Mass Ratio for Contact Close Binary Systems of W Ursae Majoris-type

    NASA Astrophysics Data System (ADS)

    Arbutina, Bojan

    2009-09-01

    Extreme mass ratio close binaries of W UMa-type represent an interesting class of objects in which 1M main-sequence star is in contact with a significantly less massive companion (M0.1M). Earlier theoretical investigations of these systems found that there is a minimum mass ratio q=M/M?0.085-0.095 (obtained for n=3 polytrope-fully radiative primary) above which these systems are stable. If the mass ratio is lower than minimum, a tidal instability develops (Darwin's instability). This instability, which is secular, growing on a viscous dissipation timescale, eventually forces the stars to merge into a single, rapidly rotating object (such as FK Com-type stars or blue stragglers), implying that such systems would not be observed. There appear to be, however, some W UMa-type binaries with empirically obtained q values below the theoretical limit for stability. The aim of this dissertation was to try to resolve the discrepancy between theory and observations by considering rotating polytropes. Other candidate systems for stellar mergers such as AM CVn-type stars have also been discussed in the dissertation.

  7. Effects of dietary n-6:n-3 ratio on immune and reproductive systems of pullet chicks.

    PubMed

    Pilevar, M; Arshami, J; Golian, A; Basami, M R

    2011-08-01

    The objective of this study was to examine the effects of dietary n-6:n-3 ratio on immune and reproduction systems of Leghorn pullet chicks. A total of 216 Hy-Line W-36 pullet chicks (1 d old) were randomly assigned to 3 diets (n-6:n-3 ratios of 10, 6, and 2) until 22 wk of age. The Optomega-50 (Optivite International Ltd., Nottinghamshire, UK) containing 50% salmon fish oil was used as an n-3 source. Pullets were injected with SRBC suspension at 6 and 9 wk and anti-SRBC titers were measured 7 and 14 d after each immunization. The antibody (Ab) titers for Newcastle disease (ND), avian influenza, infectious bronchitis (IB), and infectious bursal disease (IBD) were determined at 4, 6, 10, 14, and 18 wk of age. Pullets fed diet with the n-6:n-3 ratio of 2 had higher feed consumption and lower BW gain (P < 0.05) compared those fed diets with the ratios of 6 and 10. The results demonstrated that the different dietary n-6:n-3 ratios did not have a significant effect on the anti-SRBC titers in pullets serum (P > 0.05). The Ab production against avian influenza vaccine was increased in pullets fed diet containing the n-6:n-3 ratio of 10 at wk 10 and 14 and increased for ND at only 14 wk (P < 0.05). On the other hand, the Ab response to IBD (14 wk) and IB (14 wk) vaccines was increased when pullets were fed diet containing a ratio of 6 (P < 0.05). The pullets fed diet with the n-6:n-3 ratio of 2 showed lower egg production and late sexual maturity (P > 0.05) whereas ovary weight (P = 0.01) and number of large yellow follicles (P = 0.049) were significantly decreased at first oviposition. Our results revealed that the supplementation of Optomega-50 as a source of n-3 to decrease the n-6:n-3 ratio in diet significantly increased Ab production for ND, IB, and IBD in pullet chicks with slight reduction in reproductive organs weight at early production. PMID:21753213

  8. First measurement of electron temperature from signal ratios in a double-pass Thomson scattering system

    SciTech Connect

    Tojo, H.; Itami, K.; Hatae, T.; Ejiri, A.; Yamaguchi, T.; Takase, Y.; Hiratsuka, J.

    2012-02-15

    This paper presents an experimental demonstration to determine electron temperature (T{sub e}) with unknown spectral sensitivity (transmissivity) in a Thomson scattering system. In this method, a double-pass scattering configuration is used and the scattered lights from each pass (with different scattering angles) are measured separately. T{sub e} can be determined from the ratio of the signal intensities without knowing a real chromatic dependence in the sensitivity. Note that the wavelength range for each spectral channel must be known. This method was applied to the TST-2 Thomson scattering system. As a result, T{sub e} measured from the ratio (T{sub e,r}) and T{sub e} measured from a standard method (T{sub e,s}) showed a good agreement with <|T{sub e,r}-T{sub e,s}|/T{sub e,s}>= 7.3%.

  9. ASAS J083241+2332.4: A New Extreme Low Mass Ratio Overcontact Binary System

    NASA Astrophysics Data System (ADS)

    Sriram, K.; Malu, S.; Choi, C. S.; Vivekananda Rao, P.

    2016-03-01

    We present the R- and V-band CCD photometry and Hα line studies of an overcontact binary ASAS J083241+2332.4. The light curves exhibit totality along with a trace of the O’Connell effect. The photometric solution indicates that this system falls into the category of extreme low-mass ratio overcontact binaries with a mass ratio, q ∼ 0.06. Although a trace of the O’ Connell effect is observed, constancy of the Hα line along various phases suggest that a relatively higher magnetic activity is needed for it to show a prominent fill-in effect. The study of O–C variations reveals that the period of the binary shows a secular increase at the rate of dP/dt ∼ 0.0765 s years‑1, which is superimposed by a low, but significant, sinusoidal modulation with a period of ∼8.25 years. Assuming that the sinusoidal variation is due to the presence of a third body, orbital elements have been derived. There exist three other similar systems, SX Crv, V857 Her, and E53, which have extremely low mass ratios and we conclude that ASAS J083241+2332.4 resembles SX Crv in many respects. Theoretical studies indicate that at a critical mass ratio range, qcritical = 0.07–0.09, overcontact binaries should merge and form a fast rotating star, but it has been suggested that qcritical can continue to fall up to 0.05 depending on the primary's mass and structure. Moreover, the obtained fill-out factors (50%–70%) indicate that mass loss is considerable and hydrodynamical simulations advocate that mass loss from L2 is mandatory for a successful merging process. Comprehensively, the results indicate that ASAS J083241+2332.4 is at a stage of merger. The pivotal role played by the subtle nature of the derived mass ratio in forming a rapidly rotating star has been discussed.

  10. A high-speed four-wavelength infrared pyrometer for low-temperature shock physics experiments

    NASA Astrophysics Data System (ADS)

    Seifter, A.; Boboridis, K.; Payton, J. R.; Obst, A. W.

    2005-03-01

    In addition to the standard problems associated with contactless temperature measurements, pyrometry in shock physics experiments has many additional concerns. These include background temperatures which are often higher than the substrate temperature, non-uniform sample temperature due to hotspots and ejecta, fast sample motion up to several km.s-1, fast-changing sample emissivity at shock breakout, and very short measurement times. We have designed a four channel, high speed near-infrared (NIR) pyrometer for measurements in the 400 to 1000K blackbody temperature range. The front end optics are specific to each experiment, utilizing preferably reflective optics in order to mitigate spectral dispersion. Next-generation instruments under development are also discussed.

  11. A high-speed, four-wavelength infrared pyrometer for low temperature shock physics experiments

    SciTech Connect

    Seifter, A.; Boboridis, K.; Payton, J. R.; Obst, A. W.

    2004-01-01

    In addition to the standard problems associated with contactless temperature measurements, pyrometry in shock physics experiments has many additional concerns. These include background temperatures which are often higher than the substrate temperature, non-uniform sample temperature due to hotspots and ejecta, fast sample motion up to several km s{sup -1}, fast-changing sample emissivity at shock breakout, and very short measurement times. We have designed a four channel, high speed near-infrared (NIR) pyrometer for measurements in the 400 to 1000K blackbody temperature regime. The front end optics are specific to each experiment, utilizing preferably reflective optics in order to mitigate spectral dispersion. Next-generation instruments under development are also discussed.

  12. Simulation of signal-to-noise ratio for the laser range-gated imaging system

    NASA Astrophysics Data System (ADS)

    Liang, Weiwei; Chen, Qianrong; Hao, Yongwang; Guo, Hao; Zhang, Wenpan

    2015-10-01

    The laser active imaging system is widely used in night vision, underwater imaging, three-dimension scene imaging and other civilian applications, and the system's detected range increase greatly comparing with the passive imaging system. In recent years, with rapid development of sensor and laser source technique, the laser range-gated imaging system is achieved based on high peak power pulsed laser and gated intensified CCD(ICCD), and it is well known for its properties such as high suppression of backscatter noise from fog and other obscurants, high resolution, long detection range and direct visualization. However, the performance of the laser range-gated imaging system is seriously affected by many factors, and the relationships between system's Signal-to-Noise Ratio (SNR) and influence factors are not further elaborated. In this paper, the simulation of SNR for the laser range-gated imaging system is studied. The principle of the laser range-gated imaging system is shown firstly, and the range equation is derived by means of deducing laser illuminating model according to the principle of laser radar and the characters of objects and the detectors. And then, the sources of noise are analyzed by accurately modeling all noise sources in the detection system, the model of SNR for laser range-gated imaging system is established. Finally, the relationships between SNR of system and influence factors such as gating time, laser pulse width and repetition frequency are discussed, and correspondingly the solutions are proposed.

  13. The Minimum Mass Ratio for Contact Close Binary Systems of W Ursae Majoris-Type

    NASA Astrophysics Data System (ADS)

    Arbutina, B.

    2012-12-01

    The main research topic of this dissertation are extreme mass ratio contact close binary systems, q ? 0.1, of W Ursae Majoris (W UMa) type. These close binaries (CBs) represent an interesting class of objects in which "normal", approximately one solar mass main-sequence star is in contact with a significantly less massive companion, M_2 0.1 M_?. Earlier theoretical investigations of these systems found that there is a minimum mass ratio q_{min} = M_2/M_1 = 0.085 - 0.095 (obtained for n = 3 polytrope - fully radiative primary) above which these CBs are stable and could be observed. If the mass ratio is lower than q_{min}, or, equivalently, if orbital angular momentum is only about three times larger than the spin angular momentum of a massive primary, a tidal instability develops (Darwin's instability) forcing eventually the stars to merge into a single, rapidly rotating object (such as FK Com-type stars or blue stragglers). However, there appear to be some W UMa-type CBs with empirically obtained values for the mass ratio below the theoretical limit for stability. The aim of this dissertation is to try to resolve the discrepancy between theory and observations by considering rotating polytropes. By including in theory the effects of higher central condensation due to rotation we were able to reduce qmin to the new theoretical value q_{min} = 0.070-0.074, for the overcontact degree f = 0 - 1, which is more consistent with the observed population. Other candidate systems for stellar mergers such as AM CVn-type stars have also been discussed in the dissertation.

  14. Carbon and nitrogen isotope ratios of juvenile winter flounder as indicators of inputs to estuarine systems.

    PubMed

    Pruell, Richard J; Taplin, Bryan K

    2015-12-30

    Stable carbon and nitrogen isotope ratios were measured in young-of-the-year (YOY) winter flounder, Pseudopleuronectes americanus, collected from several Rhode Island, USA estuarine systems. These included three coastal lagoons, an estuarine river and Narragansett Bay. The ?(13)C trends observed along transects in several systems showed isotopically depleted terrestrial signals in the upper reaches of the estuaries. Significant differences (P<0.05) in ?(15)N were observed among all estuarine systems and these differences correlated (P<0.01) with human population densities in the watersheds. Although Narragansett Bay has a strong north-south gradient in nutrient concentrations this trend was not reflected in flounder ?(15)N. The northernmost station with the highest nutrient concentrations unexpectedly had significantly lower ?(15)N values. Depleted ?(15)N values at this nutrient-rich station may indicate that concentration-dependent fractionation needs to be considered when using nitrogen isotope ratios in biota to monitor anthropogenic nitrogen inputs in systems with high nitrogen loadings. PMID:26541984

  15. Estimation of Theaflavins (TF) and Thearubigins (TR) Ratio in Black Tea Liquor Using Electronic Vision System

    NASA Astrophysics Data System (ADS)

    Akuli, Amitava; Pal, Abhra; Ghosh, Arunangshu; Bhattacharyya, Nabarun; Bandhopadhyya, Rajib; Tamuly, Pradip; Gogoi, Nagen

    2011-09-01

    Quality of black tea is generally assessed using organoleptic tests by professional tea tasters. They determine the quality of black tea based on its appearance (in dry condition and during liquor formation), aroma and taste. Variation in the above parameters is actually contributed by a number of chemical compounds like, Theaflavins (TF), Thearubigins (TR), Caffeine, Linalool, Geraniol etc. Among the above, TF and TR are the most important chemical compounds, which actually contribute to the formation of taste, colour and brightness in tea liquor. Estimation of TF and TR in black tea is generally done using a spectrophotometer instrument. But, the analysis technique undergoes a rigorous and time consuming effort for sample preparation; also the operation of costly spectrophotometer requires expert manpower. To overcome above problems an Electronic Vision System based on digital image processing technique has been developed. The system is faster, low cost, repeatable and can estimate the amount of TF and TR ratio for black tea liquor with accuracy. The data analysis is done using Principal Component Analysis (PCA), Multiple Linear Regression (MLR) and Multiple Discriminate Analysis (MDA). A correlation has been established between colour of tea liquor images and TF, TR ratio. This paper describes the newly developed E-Vision system, experimental methods, data analysis algorithms and finally, the performance of the E-Vision System as compared to the results of traditional spectrophotometer.

  16. Hyper-entanglement based system with enhanced resolution, signal to noise ratio, and measurement time

    NASA Astrophysics Data System (ADS)

    Smith, James F.

    2013-05-01

    A hyper-entanglement based atmospheric imaging/detection system involving only a signal and an ancilla photon will be considered for optical and infrared frequencies. Only the signal photon will propagate in the atmosphere and its loss will be classical. The ancilla photon will remain within the sensor experiencing low loss. Closed form expressions for the wave function, normalization, density operator, reduced density operator, symmetrized logarithmic derivative, quantum Fisher information, quantum Cramer-Rao lower bound, coincidence probabilities, probability of detection, probability of false alarm, probability of error after M measurements, signal to noise ratio, quantum Chernoff bound, time-on-target expressions related to probability of error and resolution will be provided. The effect of noise in every mode will be included as well as loss. The system will provide the basic design for an imaging/detection systems functioning at optical or infrared frequencies that offer better than classical angular and range resolution. Optimization for enhanced resolution will be included. The signal to noise ratio will be increased by a factor equal to the number of modes employed during the hyper-entanglement process. Likewise, the measurement time can be reduced by the same factor. The hyper-entanglement generator will typically make use of entanglement in polarization, energy-time, orbital angular momentum, etc. Mathematical results will be provided describing the system's performance as a function of loss mechanisms and noise.

  17. Decentralized PID controller for TITO systems using characteristic ratio assignment with an experimental application.

    PubMed

    Hajare, V D; Patre, B M

    2015-11-01

    This paper presents a decentralized PID controller design method for two input two output (TITO) systems with time delay using characteristic ratio assignment (CRA) method. The ability of CRA method to design controller for desired transient response has been explored for TITO systems. The design methodology uses an ideal decoupler to reduce the interaction. Each decoupled subsystem is reduced to first order plus dead time (FOPDT) model to design independent diagonal controllers. Based on specified overshoot and settling time, the controller parameters are computed using CRA method. To verify performance of the proposed controller, two benchmark simulation examples are presented. To demonstrate applicability of the proposed controller, experimentation is performed on real life interacting coupled tank level system. PMID:26521724

  18. Spatio-temporal patterns of C : N : P ratios in the northern Benguela upwelling system

    NASA Astrophysics Data System (ADS)

    Flohr, A.; van der Plas, A. K.; Emeis, K.-C.; Mohrholz, V.; Rixen, T.

    2014-02-01

    On a global scale the ratio of fixed nitrogen (N) and phosphate (P) is characterized by a deficit of N with regard to the classical Redfield ratio of N : P = 16 : 1 reflecting the impact of N loss occurring in the oceanic oxygen minimum zones. The northern Benguela upwelling system (NBUS) is known for losses of N and the accumulation of P in sub- and anoxic bottom waters and sediments of the Namibian shelf resulting in low N : P ratios in the water column. To study the impact of the N : P anomalies on the regional carbon cycle and their consequences for the export of nutrients from the NBUS into the oligotrophic subtropical gyre of the South Atlantic, we measured dissolved inorganic carbon (CT), total alkalinity (AT), oxygen (O2) and nutrient concentrations in February 2011. The results indicate increased P concentrations over the Namibian shelf due to P efflux from sediments resulting in a C : N : P : -O2 ratio of 106 : 16 : 1.6 : 138. N reduction further increase C : N and reduce N : P ratios in those regions where O2 concentrations in bottom waters are < 20 μmol kg-1. However, off the shelf along the continental margin, the mean C : N : P : -O2 ratio is again close to the Redfield stoichiometry. Additional nutrient data measured during two cruises in 2008 and 2009 imply that the amount of excess P, which is created in the bottom waters on the shelf, and its export into the subtropical gyre after upwelling varies through time. The results further reveal an inter-annual variability of excess N within the South Atlantic Central Water (SACW) that flows from the north into the NBUS, with highest N values observed in 2008. It is postulated that the N excess in SACW occurred due to the impact of remineralized organic matter produced by N2 fixation and that the magnitude of excess P formation and its export is governed by inputs of excess N along with SACW flowing into the NBUS. Factors controlling N2 fixation north of the BUS need to be addressed in future studies to better understand the role of the NBUS as a P source and N sink in the coupled C : N : P cycles.

  19. Performance enhancement for long distance BOTDR sensing system based on high extinction ratio probe pulse generator

    NASA Astrophysics Data System (ADS)

    Zhang, Yixin; Xia, Lan; Wu, Xuelin; Zhang, Xuping; Wang, Guanghui

    2014-10-01

    The leakage light of an electro-optic modulator (EOM) induced by its finite extinction ratio (ER) may degrade the performance of Brillouin optical time domain reflectometer sensing system, especially for long distance measurement. In this letter, the configuration of a high ER probe pulse generator assisted by synchronous optical switch has been presented. A dual pulses interferometric method was also proposed to determine the dynamic ER value (DER) of the generated probe pulse. Contrast experiments have been performed to verify the effect of the proposed method in a BOTDR system and the results have shown that the performance of a long distance BOTDR sensing system can be improved observably with the proposed high ER probe pulse generator. At the end of a 48.5km sensing fiber, the maximum uncertainty of temperature measurement has been reduced from 5.2° to 0.8° with 25m spatial resolution after we improved the extinction ratio of probe pulse from 35dB to 65dB.

  20. Lymph node ratio-based staging system for esophageal squamous cell carcinoma

    PubMed Central

    Chen, Shao-Bin; Weng, Hong-Rui; Wang, Geng; Zou, Xiao-Fang; Liu, Di-Tian; Chen, Yu-Ping; Zhang, Hao

    2015-01-01

    AIM: To analyze a modified staging system utilizing lymph node ratio (LNR) in patients with esophageal squamous cell carcinoma (ESCC). METHODS: Clinical data of 2011 patients with ESCC who underwent surgical resection alone between January 1995 and June 2010 at the Cancer Hospital of Shantou University Medical College were reviewed. The LNR, or node ratio (Nr) was defined as the ratio of metastatic LNs ompared to the total number of resected LNs. Overall survival between groups was compared with the log-rank test. The cutoff point of LNR was established by grouping patients with 10% increment in Nr, and then combining the neighborhood survival curves using the log-rank test. A new TNrM staging system, was constructed by replacing the American Joint Committee on Cancer (AJCC) N categories with the Nr categories in the new TNM staging system. The time-dependent receiver operating characteristic curves were used to evaluate the predictive performance of the seventh edition AJCC staging system and the TNrM staging system. RESULTS: The median number of resected LNs was 12 (range: 4-44), and 25% and 75% interquartile rangeswere8 and 16. Patients were classified into four Nr categories with distinctive survival differences (Nr0: LNR = 0; Nr1: 0% < LNR ? 10%; Nr2: 10% < LNR ? 20%; and Nr3: LNR > 20%). From N categories to Nr categories, 557 patients changed their LN stage. The median survival time (MST) for the four Nr categories (Nr0-Nr3) was 155.0 mo, 39.0 mo, 28.0 mo, and 19.0 mo, respectively, and the 5-year overall survival was 61.1%, 41.1%, 33.0%, and 22.9%, respectively (P < 0.001). Overall survival was significantly different for the AJCC N categories when patients were subgrouped into 15 or more vs fewer than 15 examined nodes, except for the N3 category (P = 0.292). However, overall survival was similar when the patients in all four Nr categories were subgrouped into 15 or more vs fewer than 15 nodes. Using the time-dependent receiver operating characteristic, we found that the Nr category and TNrM stage had higher accuracy in predicting survival than the AJCC N category and TNM stage. CONCLUSION: A staging system based on LNR may have better prognostic stratification of patients with ESCC than the current TNM system, especially for those undergoing limited lymphadenectomy. PMID:26139998

  1. Radiation detection method and system using the sequential probability ratio test

    DOEpatents

    Nelson, Karl E.; Valentine, John D.; Beauchamp, Brock R.

    2007-07-17

    A method and system using the Sequential Probability Ratio Test to enhance the detection of an elevated level of radiation, by determining whether a set of observations are consistent with a specified model within a given bounds of statistical significance. In particular, the SPRT is used in the present invention to maximize the range of detection, by providing processing mechanisms for estimating the dynamic background radiation, adjusting the models to reflect the amount of background knowledge at the current point in time, analyzing the current sample using the models to determine statistical significance, and determining when the sample has returned to the expected background conditions.

  2. System-specific spare rail vehicle ratios: A synthesis of transit practice. Final report

    SciTech Connect

    Pierce, J.T.

    1995-12-31

    This synthesis addresses the system-specific variables that directly impact fleet size, and the spare ratios that are maintained by individual transit agencies. From the information obtained, it appears that most rail transit agencies closely monitor the spare vehicles they maintain to maximize efficiency and thereby reduce operating costs. This report of the Transportation Research Board describes operating environments at 21 selected rail transit agencies of various sizes in key geographical locations in North America. It contains survey information about operating practices, impediments, and strategies used to appropriately size fleets within each agency`s operating context.

  3. Alpha and gamma radiation effects on air-water systems at high gas/liquid ratios

    SciTech Connect

    Wronkiewicz, D.J.; Bates, J.K.

    1993-08-01

    Radiolysis tests were conducted on air-water systems to examine the effects of radiation on liquid phase chemistry under high gas/liquid volume (G/L) ratios that are characteristic of an unsaturated nuclear waste repository setting. Test parameters included temperatures of 25, 90, and 200{degrees}C; gamma vs. alpha radiation; dose rates of {approximately}3500 and 50,000 rad/h; and G/L ratios of 10 and 100. Formate, oxalate, and total organic carbon contents increased during irradiation of the air-water systems in gamma and alpha tests at low-dose rate ({approximately}3500 rad/h). Increases in organic components were not observed for tests run at 200{degrees}C or high-dose rates (50,000 rad/h). In the tests where increases in organics occurred, the formate and oxalate were preferentially enriched in solutions that were rinsed from the test vessel walls. Nitrate (NO{sub 3}{sup {minus}}) is the dominant anion produced during the radiolysis reactions. Significant nitrite (NO{sub 2}{sup {minus}}) also occurs in some high-dose rate tests, with the reduced form of nitrogen possibly resulting from reactions with the test vessels. These results indicate that nitrogen acids are being produced and concentrated in the limited quantities of solution present in the tests. Nitrate + nitrite production varied inversely with temperature, with the lowest quantities being detected for the higher temperature tests. The G(NO{sub 3}{sup {minus}} + NO{sub 2}{sup {minus}}) values for the 25, 90, and 200{degrees}C experiments with gamma radiation are 3.2 {+-} 0.7, 1.3 {+-} 1.0, and 0.4 {+-} 0.3, respectively. Thus, the elevated temperatures expected early in the life of a repository may counteract pH decreases resulting from nitrogen acid production. Little variation was observed in G values as a function of dose rate or gas/liquid ratio.

  4. The genetic sex-determination system predicts adult sex ratios in tetrapods.

    PubMed

    Pipoly, Ivett; Bkony, Veronika; Kirkpatrick, Mark; Donald, Paul F; Szkely, Tams; Liker, Andrs

    2015-11-01

    The adult sex ratio (ASR) has critical effects on behaviour, ecology and population dynamics, but the causes of variation in ASRs are unclear. Here we assess whether the type of genetic sex determination influences the ASR using data from 344 species in 117 families of tetrapods. We show that taxa with female heterogamety have a significantly more male-biased ASR (proportion of males: 0.55 0.01 (mean s.e.m.)) than taxa with male heterogamety (0.43 0.01). The genetic sex-determination system explains 24% of interspecific variation in ASRs in amphibians and 36% in reptiles. We consider several genetic factors that could contribute to this pattern, including meiotic drive and sex-linked deleterious mutations, but further work is needed to quantify their effects. Regardless of the mechanism, the effects of the genetic sex-determination system on the adult sex ratio are likely to have profound effects on the demography and social behaviour of tetrapods. PMID:26444239

  5. Earliest rooting system and root : shoot ratio from a new Zosterophyllum plant.

    PubMed

    Hao, Shougang; Xue, Jinzhuang; Guo, Dali; Wang, Deming

    2010-01-01

    The enhanced chemical weathering by rooted vascular plants during the Silurian-Devonian period played a crucial role in altering global biogeochemical cycles and atmospheric environments; however, the documentation of early root morphology and physiology is scarce because the existing fossils are mostly incomplete. Here, we report an entire, uprooted specimen of a new Zosterophyllum Penhallow, named as Z. shengfengense, from the Early Devonian Xitun Formation (Lochkovian, c. 413 Myr old) of Yunnan, south China. This plant has the most ancient known record of a rooting system. The plant consists of aerial axes of 98 mm in height, showing a tufted habit, and a rhizome bearing a fibrous-like rooting system, c. 20 mm in length. The rhizome shows masses of branchings, which produce upwardly directed aerial axes and downwardly directed root-like axes. The completeness of Z. shengfengense made it possible to estimate the biomass allocation and root : shoot ratio. The root : shoot ratio of this early plant is estimated at a mean value of 0.028, and the root-like axes constitute only c. 3% of the total biomass. Zosterophyllum shengfengense was probably a semi-aquatic plant with efficient water use or a strong uptake capacity of the root-like axes. PMID:19825018

  6. A commercial system for automated nitrogen isotope-ratio analysis by the Rittenberg technique

    NASA Astrophysics Data System (ADS)

    Mulvaney, R. L.; Fohringer, C. L.; Bojan, V. J.; Michlik, M. M.; Herzog, L. F.

    1990-02-01

    A sequential sample treatment system is described that permits use of an isotope-ratio mass spectrometer for automated Rittenberg analyses of ammonium salts. This system is based on the design of McInteer and Montoya [Recent Developments in Mass Spectrometry in Biochemistry, Medicine and Environmental Research, edited by A. Frigerio (Elsevier, Amsterdam, 1981), Vol. 7, p. 343]. An x-y table and a set of valves under computer control are used to automatically perform hypobromite oxidations, introduce the N2 thus liberated to the mass spectrometer for isotope-ratio analysis, and effect spent sample pumpaway. Analyses can be performed on samples containing 20 ?g of N. When operated with a Nuclide Model 3-60-RMS double-collector mass spectrometer, the standard deviation for measurements at the natural abundance level (12 samples, 50 or 100 ?g of N per sample) ranged from 0.0002 to 0.000 06 at. % 15N. Throughput capacity is 100-250 samples per day, and unattended operation can continue for at least three days.

  7. Molecular beam sampling system with very high beam-to-background ratio: The rotating skimmer concept

    SciTech Connect

    Benedikt, J.; Ellerweg, D.; Keudell, A. von

    2009-05-15

    A novel method of reducing the background pressure in a vacuum system used for sampling a molecular beam from a high pressure region is presented. A triple differential pumping stage is constructed with a chopper with rotating skimmer within the first pumping stage, which serves effectively as a valve separating periodically the vacuum system from the ambient environment. The mass spectrometry measurement of the species in the molecular beam show an excellent beam-to-background ratio of 14 and a detection limit below 1 ppm. The potential of this method for detection of low density reactive species in atmospheric pressure plasmas is demonstrated for the detection of oxygen atoms generated in an atmospheric pressure microplasma source.

  8. Molecular beam sampling system with very high beam-to-background ratio: The rotating skimmer concept

    NASA Astrophysics Data System (ADS)

    Benedikt, J.; Ellerweg, D.; von Keudell, A.

    2009-05-01

    A novel method of reducing the background pressure in a vacuum system used for sampling a molecular beam from a high pressure region is presented. A triple differential pumping stage is constructed with a chopper with rotating skimmer within the first pumping stage, which serves effectively as a valve separating periodically the vacuum system from the ambient environment. The mass spectrometry measurement of the species in the molecular beam show an excellent beam-to-background ratio of 14 and a detection limit below 1 ppm. The potential of this method for detection of low density reactive species in atmospheric pressure plasmas is demonstrated for the detection of oxygen atoms generated in an atmospheric pressure microplasma source.

  9. Copy number ratios determined by two digital polymerase chain reaction systems in genetically modified grains

    NASA Astrophysics Data System (ADS)

    Pérez Urquiza, M.; Acatzi Silva, A. I.

    2014-02-01

    Three certified reference materials produced from powdered seeds to measure the copy number ratio sequences of p35S/hmgA in maize containing MON 810 event, p35S/Le1 in soybeans containing GTS 40-3-2 event and DREB1A/acc1 in wheat were produced according to the ISO Guides 34 and 35. In this paper, we report digital polymerase chain reaction (dPCR) protocols, performance parameters and results of copy number ratio content of genetically modified organisms (GMOs) in these materials using two new dPCR systems to detect and quantify molecular deoxyribonucleic acid: the BioMark® (Fluidigm) and the OpenArray® (Life Technologies) systems. These technologies were implemented at the National Institute of Metrology in Mexico (CENAM) and in the Reference Center for GMO Detection from the Ministry of Agriculture (CNRDOGM), respectively. The main advantage of this technique against the more-used quantitative polymerase chain reaction (qPCR) is that it generates an absolute number of target molecules in the sample, without reference to standards or an endogenous control, which is very useful when not much information is available for new developments or there are no standard reference materials in the market as in the wheat case presented, or when it was not possible to test the purity of seeds as in the maize case presented here. Both systems reported enhanced productivity, increased reliability and reduced instrument footprint. In this paper, the performance parameters and uncertainty of measurement obtained with both systems are presented and compared.

  10. Performance and limits of liquid chromatography isotope ratio mass spectrometry system for halogenated compounds

    NASA Astrophysics Data System (ADS)

    Gilevska, Tetyana; Gehre, Matthias; Richnow, Hans

    2014-05-01

    Compound Specific Isotope Analysis (CSIA) has been an important step for the assessment of the origin and fate of compounds in environmental science.[1] Biologically or pharmaceutically important compounds often are not amenable for gas chromatographic separation because of high polarity and lacking volatility, thermostability. In 2004 liquid chromatography isotope ratio mass spectrometry (LC-IRMS) became commercially available. LC-IRMS system intent a quantitative conversion of analytes separation into CO2 via wet oxidation with sodium persulfate in the presence of phosphoric acid while analytes are still dissolved in the aqueous liquid phase.[2] The aim of this study is to analyze the oxidation capacity of the interface of the LC-IRMS system and determine which parameters could improve oxidation of compounds which are resistant to persulfate oxidation. Oxidation capacity of the liquid chromatography isotope ratio mass spectrometry system was tested with halogenated acetic acid and a set of aromatic compounds with different substitutes. Acetic acid (AA) was taken as a model compound for complete oxidation and compared to the oxidation of other analytes on a molar basis. Correct values were obtained for di- and mono chlorinated and fluorinated and also for tribrominated acetic acid and for all studied aromatic compounds. Incomplete oxidation for trichloroacetic (TCAA) and trifluoroacetic (TFAA) acid was revealed with lower recovery compared to acetic acid and isotope fractionation leading to depleted carbon isotope composition compared to values obtained with an elementary analyzer connected to an isotope mass spectrometer Several optimization steps were tried in order to improve the oxidation of TCAA and TFAA: (i) increasing the concentration of the oxidizing agent, (ii) variation of flow rate of the oxidizing and acid solution, (iii) variation of flow rate of liquid chromatography pump (iv) addition of a catalyzer. These modifications lead to longer reaction time in the coil and increase in the concentration of radical but complete combustion of highly chlorinated or fluorinated compounds was not achieved. Due to these findings the limit for a LC-IRMS system for similar structure compounds can be predicted. 1. Elsner, M., et al., Current challenges in compound-specific stable isotope analysis of environmental organic contaminants. Analytical and Bioanalytical Chemistry, 2012. 403(9): p. 2471-2491. 2. Krummen, M., et al., A new concept for isotope ratio monitoring liquid chromatography/mass spectrometry. Rapid Communications in Mass Spectrometry, 2004. 18(19): p. 2260-2266.

  11. DEEP, LOW MASS RATIO OVERCONTACT BINARY SYSTEMS. XI. V1191 CYGNI

    SciTech Connect

    Zhu, L. Y.; Qian, S. B.; He, J. J.; Liu, L.

    2011-10-15

    Complete CCD photometric light curves in BV(RI){sub c} bands obtained on one night in 2009 for the short-period close-binary system V1191 Cygni are presented. A new photometric analysis with the 2003 version of the Wilson-Van Hamme code shows that V1191 Cyg is a W-type overcontact binary system and suggests that it has a high degree of overcontact (f = 68.6%) with very low mass ratio, implying that it is at the late stage of overcontact evolution. The absolute parameters of V1191 Cyg are derived using spectroscopic and photometric solutions. Combining new determined times of light minimum with others published in the literature, the period change of the binary star is investigated. A periodic variation, with a period of 26.7 years and an amplitude of 0.023 days, was discovered to be superimposed on a long-term period increase (dP/dt = +4.5({+-} 0.1) x 10{sup -7} days yr{sup -1}). The cyclic period oscillation may be caused by the magnetic activity cycles of either of the components or the light-time effect due to the presence of a third body with a mass of m{sub 3} = 0.77 M{sub sun} and an orbital radius of a{sub 3} = 7.6 AU, when this body is coplanar to the orbit of the eclipsing pair. The secular orbital period increase can be interpreted as a mass transfer from the less massive component to the more massive one. With the period increases, V1191 Cyg will evolve from its present low mass ratio, high filled overcontact state to a rapidly rotating single star when its orbital angular momentum is less than three times the total spin angular momentum. V1191 Cyg is too blue for its orbital period and it is an unusual W-type overcontact system with such a low mass ratio and high fill-out overcontact configuration, which is worth monitoring continuously in the future.

  12. A study on the optimal hydraulic loading rate and plant ratios in recirculation aquaponic system.

    PubMed

    Endut, Azizah; Jusoh, A; Ali, N; Wan Nik, W B; Hassan, A

    2010-03-01

    The growths of the African catfish (Clarias gariepinus) and water spinach (Ipomoea aquatica) were evaluated in recirculation aquaponic system (RAS). Fish production performance, plant growth and nutrient removal were measured and their dependence on hydraulic loading rate (HLR) was assessed. Fish production did not differ significantly between hydraulic loading rates. In contrast to the fish production, the water spinach yield was significantly higher in the lower hydraulic loading rate. Fish production, plant growth and percentage nutrient removal were highest at hydraulic loading rate of 1.28 m/day. The ratio of fish to plant production has been calculated to balance nutrient generation from fish with nutrient removal by plants and the optimum ratio was 15-42 gram of fish feed/m(2) of plant growing area. Each unit in RAS was evaluated in terms of oxygen demand. Using specified feeding regime, mass balance equations were applied to quantify the waste discharges from rearing tanks and treatment units. The waste discharged was found to be strongly dependent on hydraulic loading rate. PMID:19819130

  13. Pilot Signal Design for Massive MIMO Systems: A Received Signal-To-Noise-Ratio-Based Approach

    NASA Astrophysics Data System (ADS)

    So, Jungho; Kim, Donggun; Lee, Yuni; Sung, Youngchul

    2015-05-01

    In this paper, the pilot signal design for massive MIMO systems to maximize the training-based received signal-to-noise ratio (SNR) is considered under two channel models: block Gauss-Markov and block independent and identically distributed (i.i.d.) channel models. First, it is shown that under the block Gauss-Markov channel model, the optimal pilot design problem reduces to a semi-definite programming (SDP) problem, which can be solved numerically by a standard convex optimization tool. Second, under the block i.i.d. channel model, an optimal solution is obtained in closed form. Numerical results show that the proposed method yields noticeably better performance than other existing pilot design methods in terms of received SNR.

  14. Phase transitions in systems of hard rectangles with non-integer aspect ratio

    NASA Astrophysics Data System (ADS)

    Kundu, Joyjit; Rajesh, R.

    2015-05-01

    We investigate, using Monte Carlo simulations, the phase diagram of a system of hard rectangles of size m mk on a square lattice when the aspect ratio k is a non-integer. The existence of a disordered isotropic phase, a nematic with only orientational order, a columnar phase with orientational and partial translational order, and a high density phase with no orientational order is shown. The high density phase is a solid-like sublattice phase only if the length and width of the rectangles are not mutually prime, else, it is an isotropic phase. The minimum value of k beyond which the nematic and columnar phases exist are determined for m = 2 and 3. The nature of the transitions between different phases is determined, and the critical exponents are numerically obtained for the continuous transitions.

  15. 40 CFR 141.536 - My system has developed an inactivation ratio; what must we do now?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false My system has developed an inactivation ratio; what must we do now? 141.536 Section 141.536 Protection of Environment ENVIRONMENTAL... has developed an inactivation ratio; what must we do now? Each log inactivation serves as a data...

  16. Control system for a multiple ratio transmission having a lockup clutch torque converter

    SciTech Connect

    Van Selous, J.S.

    1987-05-19

    This patent describes a power transmission mechanism for a driveline for a vehicle powered by an internal combustion engine. The process comprises: a hydrokinetic torque converter having a bladed impeller housing driven by the engine, a bladed turbine in the housing, a bladed stator and a turbine shaft connected to the turbine; multiple ratio gearing having a torque input member and a torque output member with plural torque flow paths defined by gear elements between the input and output members and having clutch and brake servo means for establishing selectively four forward driving speed ratios and a reverse ratio; and the highest speed ratio being an overdrive, the second highest speed ratio being a direct one-to-one speed ratio and the third highest speed ratio being an underdrive.

  17. Signal-to-noise ratio performance for detection systems of quantum dot multiplexed optical encoding

    NASA Astrophysics Data System (ADS)

    Goss, K. C.; Potter, M. E.; Messier, G. G.

    2010-06-01

    The wavelength and intensity of the spectral emission of a group of quantum dots can be altered by varying the size of the quantum dots (wavelength) and the number of the quantum dots (intensity). In this way, information and be encoded into the spectral characteristics of the group of quantum dots emission. This approach has been proposed for the application of tagging thousands of biomolecules as well as replacing barcodes as a means to identify objects. The potential in this system rests in the ability to achieve a high information density. In this paper we model and measure the noise in the readout system that will contribute to the decrease of the information density. We also propose an alternate optical detector as a possibly simpler and cheaper design. Our results demonstrate that the signal-to-noise ratio for both the CCD and photodiode detectors has a linear relationship with time. To achieve comparable SNR, approximately 30dB, in both detectors we note that the CCD-based spectrometer requires integration times on the order of hundreds of milliseconds while the photodiode only requires tens of microseconds.

  18. Anisoplanatism effects on signal-to-noise ratio performance of adaptive optical systems

    SciTech Connect

    Troxel, S.E.; Welsh, B.M.; Roggemann, M.C.

    1995-03-01

    The effects of turbulence-induced anisoplanatism cause the performance of an adaptive-optics system to be dependent on the angular separation between the object wave front being corrected and the wave front of the reference source. One method of quantifying this angular-dependent performance is through the average optical transfer function (OTF). An equally important measure is the variance of the OTF. The variance is used together with the average OTF in the definition of a signal-to-noise ratio (SNR). Knowledge of the SNR is essential for determining the spatial frequency limit of image restoration. We present a diffraction-based method of computing the object-angle-dependent OTF SNR for an adaptive-optics system. The SNR is computed with normalized correlation functions that are valid for a wide range of atmospheric turbulence profiles and beacon-object angles. The SNR results are presented for observation angles out to 6 times the isoplanatic angle as defined by Fried. 18 refs., 10 figs.

  19. The differential Howland current source with high signal to noise ratio for bioimpedance measurement system

    SciTech Connect

    Liu, Jinzhen; Li, Gang; Lin, Ling; Qiao, Xiaoyan; Wang, Mengjun; Zhang, Weibo

    2014-05-15

    The stability and signal to noise ratio (SNR) of the current source circuit are the important factors contributing to enhance the accuracy and sensitivity in bioimpedance measurement system. In this paper we propose a new differential Howland topology current source and evaluate its output characters by simulation and actual measurement. The results include (1) the output current and impedance in high frequencies are stabilized after compensation methods. And the stability of output current in the differential current source circuit (DCSC) is 0.2%. (2) The output impedance of two current circuits below the frequency of 200 KHz is above 1 MΩ, and below 1 MHz the output impedance can arrive to 200 KΩ. Then in total the output impedance of the DCSC is higher than that of the Howland current source circuit (HCSC). (3) The SNR of the DCSC are 85.64 dB and 65 dB in the simulation and actual measurement with 10 KHz, which illustrates that the DCSC effectively eliminates the common mode interference. (4) The maximum load in the DCSC is twice as much as that of the HCSC. Lastly a two-dimensional phantom electrical impedance tomography is well reconstructed with the proposed HCSC. Therefore, the measured performance shows that the DCSC can significantly improve the output impedance, the stability, the maximum load, and the SNR of the measurement system.

  20. Associations between Optic Cup-to-disc Ratio and Systemic Factors in the Healthy Korean Population

    PubMed Central

    Kim, Yang Jae; Shim, Seong Hee; Bae, Jeong Hun; Park, Ki Ho

    2015-01-01

    Purpose To assess the relationships between optic cup-to-disc ratio (CDR) and age, sex, and other demographic and health characteristics in the healthy Korean population. Methods The study design was retrospective and population-based. A total of 28,377 subjects who participated in the Korea National Health and Nutrition Examination Survey between 2008 and 2011 were enrolled in this study. Participants underwent structured interviews as well as systemic and ophthalmic examinations. Patients with glaucoma who were diagnosed using the International Society of Geographical and Epidemiological Ophthalmology classification were excluded. Changes in vertical CDR were examined by age in relation to systemic variables on multiple regression analysis. Results The mean vertical CDR was 0.34 ± 0.12. The vertical CDR increased with age from subjects in their 20s to those in their 80s (p < 0.001). The mean CDR in males was significantly higher than that of females (p < 0.001). On multiple regression analysis, the vertical CDR was positively associated with age (p < 0.001), male sex (p < 0.001), diastolic blood pressure (p = 0.009), and intraocular pressure (p < 0.001) but was negatively associated with body mass index (p < 0.001). Conclusions Greater vertical CDR was related to age, male sex, higher diastolic blood pressure, higher intraocular pressure, and lower body mass index in healthy Koreans. PMID:26457040

  1. Nitrogen Isotope Ratios of Juvenile Winter Flounder as an Indicator of Anthropogenic Nitrogen Inputs to Estuarine Systems

    EPA Science Inventory

    Nitrogen isotope ratios (?15N) were measured in muscle tissue of juvenile winter flounder, Pseudopleuronectes americanus, collected from several estuarine systems (lagoons, river, bay) along the coast of Rhode Island, USA over a three-year period. Significant differences i...

  2. Contributed Review: Absolute spectral radiance calibration of fiber-optic shock-temperature pyrometers using a coiled-coil irradiance standard lamp

    NASA Astrophysics Data System (ADS)

    Fat'yanov, O. V.; Asimow, P. D.

    2015-10-01

    We describe an accurate and precise calibration procedure for multichannel optical pyrometers such as the 6-channel, 3-ns temporal resolution instrument used in the Caltech experimental geophysics laboratory. We begin with a review of calibration sources for shock temperatures in the 3000-30 000 K range. High-power, coiled tungsten halogen standards of spectral irradiance appear to be the only practical alternative to NIST-traceable tungsten ribbon lamps, which are no longer available with large enough calibrated area. However, non-uniform radiance complicates the use of such coiled lamps for reliable and reproducible calibration of pyrometers that employ imaging or relay optics. Careful analysis of documented methods of shock pyrometer calibration to coiled irradiance standard lamps shows that only one technique, not directly applicable in our case, is free of major radiometric errors. We provide a detailed description of the modified Caltech pyrometer instrument and a procedure for its absolute spectral radiance calibration, accurate to 5%. We employ a designated central area of a 0.7 demagnified image of a coiled-coil tungsten halogen lamp filament, cross-calibrated against a NIST-traceable tungsten ribbon lamp. We give the results of the cross-calibration along with descriptions of the optical arrangement, data acquisition, and processing. We describe a procedure to characterize the difference between the static and dynamic response of amplified photodetectors, allowing time-dependent photodiode correction factors for spectral radiance histories from shock experiments. We validate correct operation of the modified Caltech pyrometer with actual shock temperature experiments on single-crystal NaCl and MgO and obtain very good agreement with the literature data for these substances. We conclude with a summary of the most essential requirements for error-free calibration of a fiber-optic shock-temperature pyrometer using a high-power coiled tungsten halogen irradiance standard lamp.

  3. Contributed Review: Absolute spectral radiance calibration of fiber-optic shock-temperature pyrometers using a coiled-coil irradiance standard lamp.

    PubMed

    Fat'yanov, O V; Asimow, P D

    2015-10-01

    We describe an accurate and precise calibration procedure for multichannel optical pyrometers such as the 6-channel, 3-ns temporal resolution instrument used in the Caltech experimental geophysics laboratory. We begin with a review of calibration sources for shock temperatures in the 3000-30,000 K range. High-power, coiled tungsten halogen standards of spectral irradiance appear to be the only practical alternative to NIST-traceable tungsten ribbon lamps, which are no longer available with large enough calibrated area. However, non-uniform radiance complicates the use of such coiled lamps for reliable and reproducible calibration of pyrometers that employ imaging or relay optics. Careful analysis of documented methods of shock pyrometer calibration to coiled irradiance standard lamps shows that only one technique, not directly applicable in our case, is free of major radiometric errors. We provide a detailed description of the modified Caltech pyrometer instrument and a procedure for its absolute spectral radiance calibration, accurate to ±5%. We employ a designated central area of a 0.7× demagnified image of a coiled-coil tungsten halogen lamp filament, cross-calibrated against a NIST-traceable tungsten ribbon lamp. We give the results of the cross-calibration along with descriptions of the optical arrangement, data acquisition, and processing. We describe a procedure to characterize the difference between the static and dynamic response of amplified photodetectors, allowing time-dependent photodiode correction factors for spectral radiance histories from shock experiments. We validate correct operation of the modified Caltech pyrometer with actual shock temperature experiments on single-crystal NaCl and MgO and obtain very good agreement with the literature data for these substances. We conclude with a summary of the most essential requirements for error-free calibration of a fiber-optic shock-temperature pyrometer using a high-power coiled tungsten halogen irradiance standard lamp. PMID:26520933

  4. Effective spectral emissivity measurements of superalloys and YSZ thermal barrier coating at high temperatures using a 1.6?m single wavelength pyrometer

    NASA Astrophysics Data System (ADS)

    Alaruri, Sami; Bianchini, Lisa; Brewington, Andrew

    1998-07-01

    A method which employs an integrating sphere and a single-wavelength (1.6 ?m) pyrometer for measuring the spectral effective emissivities of superalloys in the temperature range (=650-1050C) is described. The spectral effective emissivities for five superalloys, namely, MARM-247, MARM-509, CMSX-4, Inconel-718, N-155 and two Ren-N6 samples coated with YSZ thermal barrier coating were measured. Correcting the pyrometer measurements for the variations in the object emissivity would reduce the uncertainty in the temperature measurements to <1%.

  5. Mobile lidar system for measurement of water vapor mixing ratio and ozone number density

    NASA Technical Reports Server (NTRS)

    Whiteman, D.

    1988-01-01

    The Water Vapor Lidar was modified and extended to make differential absorption measurements of ozone. Water vapor measurements make use of a weak molecular scattering process known as Raman scattering. It is characterized by a shift in wavelength of the scattered beam of light relative to the incident one. Some of the energy of the incident photon is converted to vibrational or rotational energy within the molecule leaving the scattered photon shifted to a slightly longer wavelength. When performing water vapor measurements, profiles are acquired of water vapor mixing ratio from near the ground to beyond 7 km every 2 minutes. By forming a color composite image of the individual profiles, the spatial and temporal evolution of water vapor is visible with vertical resolution of 75 to 150m and temporal resolution of 2 minutes. The ozone lidar is intended for use as a cross calibration facility for other stationary ozone lidar systems. The ozone measurement employs the technique known as differential absorption. The backscattered laser radiation from two different wavelengths is measured. Successful measurements of 308 nm returns were made from 80 km with an averaging period of 6 hours. Using these data and a standard atmosphere density curve, an ozone number density profile was made which agrees very well with the standard ozone curve between 20 and 40 km.

  6. A synthetic sex ratio distortion system for the control of the human malaria mosquito

    PubMed Central

    Galizi, Roberto; Doyle, Lindsey A.; Menichelli, Miriam; Bernardini, Federica; Deredec, Anne; Burt, Austin; Stoddard, Barry L.; Windbichler, Nikolai; Crisanti, Andrea

    2014-01-01

    It has been theorized that inducing extreme reproductive sex ratios could be a method to suppress or eliminate pest populations. Limited knowledge about the genetic makeup and mode of action of naturally occurring sex distorters and the prevalence of co-evolving suppressors has hampered their use for control. Here we generate a synthetic sex distortion system by exploiting the specificity of the homing endonuclease I-PpoI, which is able to selectively cleave ribosomal gene sequences of the malaria vector Anopheles gambiae that are located exclusively on the mosquitos X chromosome. We combine structure-based protein engineering and molecular genetics to restrict the activity of the potentially toxic endonuclease to spermatogenesis. Shredding of the paternal X chromosome prevents it from being transmitted to the next generation, resulting in fully fertile mosquito strains that produce >95% male offspring. We demonstrate that distorter male mosquitoes can efficiently suppress caged wild-type mosquito populations, providing the foundation for a new class of genetic vector control strategies. PMID:24915045

  7. Effects of Different Eddy Covariance Correction Schemes on Energy Balance Closure and Comparisons with the Modified Bowen Ratio System

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Eddy covariance (EC) and modified Bowen ratio (MBR) systems typically yield subtly different estimates of H, LE, and Fc. Our study analyzed the discrepancies between EC and MBR systems by first considering the role of the data processing algorithm used to estimate fluxes using EC and later examinin...

  8. Chondrites - Initial strontium-87/strontium-86 ratios and the early history of the solar system.

    NASA Technical Reports Server (NTRS)

    Wetherill, G. W.; Mark, R.; Lee-Hu, C.

    1973-01-01

    A sodium-poor, calcium-rich inclusion in the carbonaceous chondrite Allende had a Sr-87/Sr-86 ratio at the time of its formation of 0.69880, as low a value as that found in any other meteorite. The higher Sr-87/Sr-86 ratios found in ordinary chondrites indicate that their formation or isotopic equilibration occurred tens of millions of years later.

  9. Implications for the False-positive Rate in Kepler Planet Systems from Transit Duration Ratios

    NASA Astrophysics Data System (ADS)

    Morehead, Robert C.; Ford, Eric B.

    2015-01-01

    Confirming transiting exoplanet candidates through traditional follow-up methods is challenging, especially for faint host stars. Most of Kepler's validated planets relied on statistical methods to separate true planets from false-positives. Multiple transiting planet systems (MTPS) have been previously shown to have low false-positive rates and over 851 planets in MTPSs have been statistically validated so far (Lissauer et al. 2014; Rowe et al. 2014). We show that the period-normalized transit duration ratio (?) offers additional information that can be used to establish the planetary nature of these systems. We briefly discuss the observed distribution of ? for the Q1-Q16 Kepler Candidate Search. We also utilize ? to develop a Bayesian statistical framework combined with Monte Carlo methods to determine which pairs of planet candidates in a MTPS are consistent with the planet hypothesis for a sample of 676 MTPSs that include both candidate and confirmed planets. This analysis proves to be efficient and advantageous in that it only requires catalog-level bulk candidate properties and galactic population modeling to compute the probabilities of a myriad of stellar blend scenarios, without needing additional observational follow-up. Our results agree with the previous results of a low false-positive rate in the Kepler MTPSs. Out of our sample of 1,358 pairs of candidates, we find that about 100 pairs have a probability greater than 0.99 of being a MTPS associated with the target star, over 800 pairs have a probability greater than 0.99 of being a MTPS associated with the target star or another star blended in the photometric aperture. Further more, we find that well over a 1,000 pairs have a probability greater than 0.99 to be planetary in nature, either orbiting the same star or separately orbiting two different stars in the aperture. This implies, independently of any other estimates, that most of the MTPSs detected by Kepler are very likely to be planetary in nature, but that a substantial fraction could be orbiting stars other than the putative target star, and therefore may be subject to significant error in the inferred planet parameters resulting from unknown or mismeasured stellar host attributes.

  10. Distribution of local void ratio in porous media systems from 3D X-ray microtomography images

    SciTech Connect

    Al-Raoush, R.; Alshibli, K.A.

    2008-09-04

    We present in this paper a methodology to calculate the distribution of local void ratio in porous media systems from high-resolution three-dimensional images. We introduce an algorithm to calculate the distribution of local void ratio from 3D images based on distance and watershed transforms. The watershed transform is used to segment touched or overlapped particles in an efficient way and the distance transform is used to calculate the boundaries of local void regions. The algorithm is validated using computer simulated 3D images of regular packing, irregular (non-spherical particles) packing, and random uniform spherical packing. Results show that the algorithm is robust, accurate and can be used to calculate local void ratio distribution of 3D systems regardless of irregularity in shapes, sizes, or arrangement of particles. X-ray microtomography images of different glass bead systems are used to calculate distributions of local void ratio. Parameters of distributions are function of porosity and particle-size distribution. The maximum local void ratio in each system is less than 3.0 and the minimum is greater than 0.2.

  11. Flux ratio anomalies in gravitationally lensed quasars with four images: Chandra observations of 4 new systems.

    NASA Astrophysics Data System (ADS)

    Schechter, Paul

    2006-09-01

    We propose to observe four quasars lensed by intervening galaxies for a total of 55 ksec. Each quasar has four images. Comparison of the X-ray flux ratios with the corresponding optical ratios constrains the relative sizes of the two emitting regions. Comparison with predictions from smooth lens models constrains the lenses' dark matter content. There is growing evidence that the flux ratio ``anomalies'' -- the differences between the observed fluxes and those predicted by smooth models -- are yet larger in X-rays than in the optical. The implications are first, that the optical comes from a substantially larger region than predicted by Shakura-Sunyaev disks models, and second, that X-ray observations give a better handle on the dark matter content than optical observations.

  12. Carrier: Interference ratios for frequency sharing between satellite systems transmitting frequency modulated and digital television signals

    NASA Technical Reports Server (NTRS)

    Barnes, S. P.

    1979-01-01

    Results are presented of subjective and quantitative tests describing the results of interference to a particular digital television system from a frequency modulated (FM) television system, and for interference to an FM television system from a digital television system.

  13. Semi-empirical estimation of organic compound fugacity ratios at environmentally relevant system temperatures.

    PubMed

    van Noort, Paul C M

    2009-06-01

    Fugacity ratios of organic compounds are used to calculate (subcooled) liquid properties, such as solubility or vapour pressure, from solid properties and vice versa. They can be calculated from the entropy of fusion, the melting temperature, and heat capacity data for the solid and the liquid. For many organic compounds, values for the fusion entropy are lacking. Heat capacity data are even scarcer. In the present study, semi-empirical compound class specific equations were derived to estimate fugacity ratios from molecular weight and melting temperature for polycyclic aromatic hydrocarbons and polychlorinated benzenes, biphenyls, dibenzo[p]dioxins and dibenzofurans. These equations estimate fugacity ratios with an average standard error of about 0.05 log units. In addition, for compounds with known fusion entropy values, a general semi-empirical correction equation based on molecular weight and melting temperature was derived for estimation of the contribution of heat capacity differences to the fugacity ratio. This equation estimates the heat capacity contribution correction factor with an average standard error of 0.02 log units for polycyclic aromatic hydrocarbons, polychlorinated benzenes, biphenyls, dibenzo[p]dioxins and dibenzofurans. PMID:19304312

  14. Influence of COD/sulfate ratios on the integrated reactor system for simultaneous removal of carbon, sulfur and nitrogen.

    PubMed

    Yuan, Ye; Chen, Chuan; Zhao, Youkang; Wang, Aijie; Sun, Dezhi; Huang, Cong; Liang, Bin; Tan, Wenbo; Xu, Xijun; Zhou, Xu; Lee, Duu-Jung; Ren, Nanqi

    2015-01-01

    An integrated reactor system was developed for the simultaneous removal of carbon, sulfur and nitrogen from sulfate-laden wastewater and for elemental sulfur (S°) reclamation. The system mainly consisted of an expanded granular sludge bed (EGSB) for sulfate reduction and organic carbon removal (SR-CR), an EGSB for denitrifying sulfide removal (DSR), a biological aerated filter for nitrification and a sedimentation tank for sulfur reclamation. This work investigated the influence of chemical oxygen demand (COD)/sulfate ratios on the performance of the system. Influent sulfate and ammonium were fixed to the level of 600 mg SO(4)(2-) L⁻¹ and 120 mg NH(4)(+) L⁻¹, respectively. Lactate was introduced to generate COD/SO(4)(2-) = 0.5:1, 1:1, 1.5:1, 2:1, 3:1, 3.5:1 and 4:1. The experimental results indicated that sulfate could be efficiently reduced in the SR-CR unit when the COD/SO(4)(2-) ratio was between 1:1 and 3:1, and sulfate reduction was inhibited by the growth of methanogenic bacteria when the COD/SO(4)(2-) ratio was between 3.5:1 and 4:1. Meanwhile, the Org-C/S²⁻/NO(3)(-) ratios affected the S(0) reclamation efficiency in the DSR unit. When the influent COD/SO(4)(2-) ratio was between 1:1 and 3:1, appropriate Org-C/S²⁻/NO(3)(-) ratios could be achieved to obtain a maximum S° recovery in the DSR unit. For the microbial community of the SR-CR unit at different COD/SO(4)(2-) ratios, 16S rRNA gene-based high throughput Illumina MiSeq sequencing was used to analyze the diversity and potential function of the dominant species. PMID:25768217

  15. Stability and Hopf bifurcation of a delayed ratio-dependent predator-prey system

    NASA Astrophysics Data System (ADS)

    Wang, Wan-Yong; Pei, Li-Jun

    2011-04-01

    Since the ratio-dependent theory reflects the fact that predators must share and compete for food, it is suitable for describing the relationship between predators and their preys and has recently become a very important theory put forward by biologists. In order to investigate the dynamical relationship between predators and their preys, a so-called Michaelis-Menten ratio-dependent predator-prey model is studied in this paper with gestation time delays of predators and preys taken into consideration. The stability of the positive equilibrium is investigated by the Nyquist criteria, and the existence of the local Hopf bifurcation is analyzed by employing the theory of Hopf bifurcation. By means of the center manifold and the normal form theories, explicit formulae are derived to determine the stability, direction and other properties of bifurcating periodic solutions. The above theoretical results are validated by numerical simulations with the help of dynamical software WinPP. The results show that if both the gestation delays are small enough, their sizes will keep stable in the long run, but if the gestation delays of predators are big enough, their sizes will periodically fluctuate in the long term. In order to reveal the effects of time delays on the ratio-dependent predator-prey model, a ratio-dependent predator-prey model without time delays is considered. By Hurwitz criteria, the local stability of positive equilibrium of this model is investigated. The conditions under which the positive equilibrium is locally asymptotically stable are obtained. By comparing the results with those of the model with time delays, it shows that the dynamical behaviors of ratio-dependent predator-prey model with time delays are more complicated. Under the same conditions, namely, with the same parameters, the stability of positive equilibrium of ratio-dependent predator-prey model would change due to the introduction of gestation time delays for predators and preys. Moreover, with the variation of time delays, the positive equilibrium of the ratio-dependent predator-prey model subjects to Hopf bifurcation.

  16. Lipoxin A4 and Neutrophil/Lymphocyte Ratio: A Possible Indicator in Achieved Systemic Risk Factors for Periodontitis

    PubMed Central

    Do?an, Burak; Fento?lu, zlem; K?rz?o?lu, Fatma Ye?im; Kemer, Esra Sinem; Kro?lu, Banu Kale; Aksu, O?uzhan; arsancakl?, Sleyman Akif; Orhan, Hikmet

    2015-01-01

    Background The aim of this study was to evaluate the serum lipoxin A4 (LXA4) and neutrophil/lymphocyte (Ne/Ly) ratio in individuals with achieved systemic risk factors for periodontitis. Material/Methods One hundred and eighty volunteers (69 male, 111 female) who were categorized as systemically healthy control, diabetes, hyperlipidemia, obese and menopause were recruited for this cross-sectional study. Sociodemographic characteristics and oral health behaviors were recorded via questionnaire. Clinical periodontal parameters, including plaque index (PI), gingival index (GI), probing pocket depth (PD), clinical attachment level (CAL), sulcus bleeding index (SBI) and decayed, missing, and filled teeth index (DMFT), were assessed. Systemic parameters and LXA4 levels were evaluated in serum samples. Results Clinical periodontal parameters and DMFT were higher in subjects with achieved systemic risk factors than in healthy subjects. The systemically healthy with periodontitis group had higher serum LXA4 levels than the systemically healthy with non-periodontitis group (P<0.05). The Ne/Ly ratio was higher in the hyperlipidemic group with periodontitis than in the hyperlipidemic group with non-periodontitis (P<0.05). In the control group, serum LXA4 levels were positively correlated with the PD, CAL and SBI. Conclusions In the presence of periodontitis, an increase in LXA4 levels and the Ne/Ly ratio in hyperlipidemic patients could contribute to the hypothesis that these parameters could be an indicator in periodontitis and its systemic risk factors. PMID:26298769

  17. Nitrogen Isotope Ratios of Juvenile Winter Flounder as an Indicator of Anthropogenic Nitrogen Inputs to Estuarine Systems

    EPA Science Inventory

    Nitrogen isotope ratios (15N) were measured in muscle tissue of juvenile winter flounder, Pseudopleuronectes americanus, collected from several estuarine systems (lagoons, river, bay) along the coast of Rhode Island, USA over a three-year period. Significant differences i...

  18. Explicit-explicit subcycling with non-integer time step ratios for structural dynamic systems

    NASA Technical Reports Server (NTRS)

    Neal, Mark O.; Belytschko, Ted

    1989-01-01

    An explicit-explicit subcycling procedure for the finite element analysis of structural dynamics is developed. This procedure has relaxed the usual constraint of requiring integer time step ratios for adjacent nodal groups. This allows for greater advantage to be taken of local stability criteria, and thus improves the efficiency of the explicit time integrator. Example problems are included to demonstrate the accuracy and stability of the method.

  19. New theoretical models and ratio imaging techniques associated with the NASA earth resources spectral information system

    NASA Technical Reports Server (NTRS)

    Vincent, R. K.

    1974-01-01

    Four independent investigations are reported; in general these are concerned with improving and utilizing the correlation between the physical properties of natural materials as evidenced in laboratory spectra and spectral data collected by multispectral scanners. In one investigation, two theoretical models were devised that permit the calculation of spectral emittance spectra for rock and mineral surfaces of various particle sizes. The simpler of the two models can be used to qualitatively predict the effect of texture on the spectral emittance of rocks and minerals; it is also potentially useful as an aid in predicting the identification of natural atmospheric aerosol constituents. The second investigation determined, via an infrared ratio imaging technique, the best pair of infrared filters for silicate rock-type discrimination. In a third investigation, laboratory spectra of natural materials were compressed into 11-digit ratio codes for use in feature selection, in searches for false alarm candidates, and eventually for use as training sets in completely automatic data processors. In the fourth investigation, general outlines of a ratio preprocessor and an automatic recognition map processor are developed for on-board data processing in the space shuttle era.

  20. Evaluation of carbonate pore system under texture control for prediction of microporosity aspect ratio and shear wave velocity

    NASA Astrophysics Data System (ADS)

    Lima Neto, Irineu A.; Missgia, Roseane M.; Ceia, Marco A.; Archilha, Nathaly L.; Hollis, Cathy

    2015-06-01

    This work evaluates a suite of carbonate rocks from Albian age in the Campos Basin - Brazil, complemented by data from the literature, totaling 472 samples with detailed description of diagenetic features, quantitative mineralogy analyses, and P- and S-wave velocities (Vp and Vs) measured at three ranges of effective pressure loading: low (5-7.5 MPa), moderate (20 MPa) and high (40-50 MPa) values. Digital image analysis (DIA) was applied on microtomography (?CT) images to quantitatively describe the macro-mesopore system of the Albian carbonates, and was extended to characterize different textures from literature data to estimate reference values for carbonates. The methodology utilized to predict the aspect ratio of microporosity assumes three pore-space scales in two representative scenarios: 1) measured macro-mesopore aspect ratio from DIA, and 2) predicted microporosity aspect ratio, using Vp measurement as the main input parameter. The differential effective medium model (DEMM) is combined with analytical theories of data analysis to characterize microporosity. Shear modulus and microporosity aspect ratio calibrated by this methodology were used to predict Vs, which was compared to experimental data, resulting in a good match for all samples. Polynomial curves are fitted with a variety of carbonate textures by velocities at effective pressure and bulk porosity crossplots, establishing important relationships for velocity prediction. The effects of effective pressure on the pore system within dry plugs of Albian samples were evaluated by combining triaxial measurements at 0-10 MPa, relative pore volume reduction (RPVR) and microporosity aspect ratio prediction. According to the results, micropores that exhibit low aspect ratio tend to close with stress and cause an increase on Vp and Vs. A wide textural heterogeneity of data base and different digital image analysis and resolutions were employed successfully, combining rock physics methodologies and concepts to characterize carbonate pore system as microporosity and pressure effects.

  1. Real-Time Measurement of Oil Circulation Ratio in CO2 Heat Pump System Using Optical Method

    NASA Astrophysics Data System (ADS)

    Takigawa, Ryusuke; Shimizu, Takao; Matsusaka, Yukio; Gao, Lei; Honda, Tomohiro

    The lubricating oil in the refrigerant flow in a CO2 heat pump system has a great influence on cycle performance. In order to measure the OCR (Oil circulation ratio), a mixing chamber and a visual vessel were installed at the outlet of the gas-cooler. By mixing the oil and refrigerant, the liquid mixture of oil and refrigerant becomes cloudy at the outlet of the gas-cooler. By measuring the infrared ray transmittance of the oil-refrigerant liquid mixture, it was found that the transmittance decreases with an increase in the oil circulation ratio. For this reason, it is found that, in spite of immiscible refrigerant and oil, the measurement of the oil circulation ratio is possible by measuring the transmittance of infrared ray at the outlet of the gas-cooler.

  2. Acupuncture Suppresses Morphine Craving in Progressive Ratio Through the GABA System.

    PubMed

    Lee, Bong Hyo; Zhao, Rong Jie; Lee, Byung Gwon; Kim, Nam Jun; Yang, Chae Ha; Kim, Hee Young; Gwak, Young S; Lim, Sung Chul; Kim, Jae Su; Lee, Yun Kyu; Lee, Hyun Jong

    2015-08-01

    Previous studies revealed that acupuncture suppressed both morphine self-administration and morphine-seeking behavior after abstinence. Based on these results, this study examined whether acupuncture attenuated morphine-craving under a progressive ratio (PR) schedule and investigated the possible neuronal mechanism. Male Sprague-Dawley rats were trained to self-administer morphine (0.5mg/kg) at a fixed ratio for 9 days, and rats who achieved stable infusion were switched to a PR schedule. When animals had taken no more morphine for 1 hour, the number of infusions was defined as the break point (BP). After PR training, animals that had established a stable BP received acupuncture the next day. Acupuncture was applied for 1 minute immediately before the test session. Bicuculline (1.0mg/kg) and SCH 50911 (2.0mg/kg) were given 30 minutes prior to acupuncture. The c-Fos levels in the ventral tegmental area (VTA) and the nucleus accumbens (NAc) were examined. Acupuncture at SI5 reduced the BP significantly. Moreover, the effects of acupuncture were blocked by either bicuculline or SCH 50911. Immunofluorescence revealed that acupuncture at SI5 decreased c-Fos expressions in the VTA and the NAc. This study demonstrates that acupuncture at SI5 is effective for the treatment of morphine-craving and that this effect is mediated via the GABA pathway. PMID:26276453

  3. Micro-Bowen ratio system for measuring evapotranspiration in a vineyard interrow

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sparse canopy systems such as vineyards are comprised of multiple components (e.g., vines, interrow soil and/or groundcover) that each contribute to system water and energy balance. Understanding component water and energy fluxes is critical for informing management decisions aimed at improving prod...

  4. Solar load ratio method applied to commercial building active solar system sizing

    SciTech Connect

    Schnurr, N.M.; Hunn, B.D.; Williamson, K.D. III

    1981-01-01

    The hourly simulation procedure is the DOE-2 building energy analysis computer program. It is capable of calculating the loads and of simulating various control strategies in detail for both residential and commercial buildings and yet is computationally efficient enough to be used for extensive parametric studies. In addition, to a Building Service Hot Water (BSHW) System and a combined space heating and hot water system using liquid collectors for a commercial building analyzed previously, a space heating system using an air collector is analyzed. A series of runs is made for systems using evacuated tube collectors for comparison to flat-plate collectors, and the effects of additional system design parameters are investigated. Also, the generic collector types are characterized by standard efficiency curves, rather than by detailed collector specifications. (MHR)

  5. An analytical system for determining delta17O in CO2 using continuous flow-isotope ratio MS.

    PubMed

    Kawagucci, Shinsuke; Tsunogai, Urumu; Kudo, Shingo; Nakagawa, Fumiko; Honda, Hideyuki; Aoki, Shuji; Nakazawa, Takakiyo; Gamo, Toshitaka

    2005-07-15

    We developed a simple measurement system for delta17O in nanomole quantities of CO2 using continuous flow isotope ratio mass spectrometry (CF-IRMS). The analytical system consisted of a sample injection system, a helium-purged CO2 purification line, a capillary GC, a combustion unit, and CF-IRMS. A unique feature of the system is that we use molecular CO2 to determine the isotopic compositions including delta17O. The delta17O of CO2 in a sample is calculated from the mass ratios of both 45/44 and 46/44 of two different kinds of CO2, which have been purified quantitatively from different aliquots of a sample. While one aliquot (rCO2) flows into IRMS directly, the other (eCO2) flows through a CuO unit (900 degrees C) prior to injection into IRMS, to exchange oxygen atoms in the sample CO2 molecules with those in CuO for which we can assume Delta17O = 0. In our system, we introduce both rCO2 and eCO2 alternately to IRMS repeatedly by using an automatic multianalytical system to improve analytical precision statistically. The standard deviation of 0.35 per thousand for Delta17O can be realized using as little as 8.7 nmol CO2 in a approximately 3-h analysis. Based on this system, we have quantified delta17O in the stratospheric CO2 over Japan. PMID:16013867

  6. Martian Post-Impact Hydrothermal Systems: Effects of Permeability and Freezing on Surface Discharge and Water:Rock Ratios

    NASA Astrophysics Data System (ADS)

    Barnhart, C. J.; Nimmo, F.; Travis, B. J.

    2008-12-01

    A km-scale bolide delivers enough energy to heat subsurface water, and drive hydrothermal circulation (Abramov and Kring, 2005). This post-impact hydrothermal (PIH) circulation can lead to surface discharge of water, and chemical alteration - both are potentially detectable. We present the effects that permeability and freezing have on discharge and water:rock (W/R) ratios. We simulate the evolution of PIH systems using MAGHNUM (detailed in Travis et al., 2003). MAGHNUM solves the time-dependent transport of water and heat through a porous medium, incorporating phase transitions between ice (applicable to Mars), vapor and water. PIH evolution depends on heat sources and permeability (k); these, in turn, control discharge and chemical alteration which depends on both the peak temperatures and the W/R ratio (Schwenzer and Kring, 2008). Recently, CRISM detected phyllosilicate-rich material within ~45 km craters (Mustard et al., 2008) and the HiRISE camera imaged gullies, some emanating from central peaks, within many high latitude craters. We model a 45 km crater created by a 3.9 km dia., 7 km/s impactor. Simulations run for 100,000 yrs in a 2D axisymmetric domain with a heat flux of 32.5 mW m-2. Thus far we have tested systems with a range of surface k's (10-4 to 1 darcys) that decay exponentially with depth and are exposed to two surface temperatures (5°C and -53°C). In general W/R ratios increase with increased k. Focusing in on the upper 200 m at the center of the crater, fluid temperatures remain > 100°C for 9000 yrs and flow yields W/R ratios of 10 when exposed to a surface temperature of 5°C. Dropping the surface temperature below freezing to a Mars-like - 53°C maintains upper 200 m temperatures > 100°C for only 600 yrs and W/R ratios are reduced to 1. Higher permeabilities yield higher W/R ratios but reduced time exposure to high temperatures. When surface temperatures are below freezing total system discharge is roughly independent of k for modest permeabilities but the time until the surface freezes increases with lower k. Freezing reduces both W/R ratios and discharge because ice closes pores and restricts flow.

  7. Tuning the current ratio of a CPV system to maximize the energy harvesting in a particular location

    NASA Astrophysics Data System (ADS)

    Victoria, M.; Askins, S.; Nuez, R.; Domnguez, C.; Herrero, R.; Antn, I.; Sala, G.; Ruz, J. M.

    2013-09-01

    A method based on experimental data is proposed to optimize the energy harvesting of a silicone-on-glass Fresnel-lens based CPV system. It takes into account the spectral variations along the year in a particular location as well as the thermal and spectral sensitivities of the optics and solar cell. In addition, different alternatives to tune the top/middle subcells current ratio in a CPV module are analyzed and their capacity to maximize the annually produced energy is quantified.

  8. Companding scheme for peak-to-average power ratio reduction in optical orthogonal frequency division multiplexing systems

    NASA Astrophysics Data System (ADS)

    Wang, Dong; Zou, Nianyu; Cui, Gaofeng; Yang, Yi; Namihira, Yoshinori; Zhang, Yinghai

    2012-11-01

    A companding method for peak-to-average power ratio (PAPR) reduction in optical orthogonal frequency division multiplexing systems has been proposed and simulated. The proposed scheme is based on the modified hyperbolic tangent transform, which can enlarge the small signals and compress the large signals while keeping the average power invariant. Simulation results verify that the proposed companding scheme can markedly decrease the PAPR, and a good bit error rate performance is obtained.

  9. Wind tunnel tests of high-lift systems for advanced transports using high-aspect-ratio supercritical wings

    NASA Technical Reports Server (NTRS)

    Allen, J. B.; Oliver, W. R.; Spacht, L. A.

    1982-01-01

    The wind tunnel testing of an advanced technology high lift system for a wide body and a narrow body transport incorporating high aspect ratio supercritical wings is described. This testing has added to the very limited low speed high Reynolds number data base for this class or aircraft. The experimental results include the effects on low speed aerodynamic characteristics of various leading and trailing edge devices, nacelles and pylons, ailerons, and spoilers, and the effects of Mach and Reynolds numbers.

  10. The Role of Boron-Chloride and Noble Gas Isotope Ratios in TVZ Geothermal Systems

    SciTech Connect

    Hulston, J.R.

    1995-01-01

    The model of the geothermal system in which deep circulating groundwater containing noble gases, at air saturated water concentrations, mixes with hot fluids of mantle origin at depth, is extended to include the effect of interaction of the ascending fluid with both solid and gaseous phases of basement (or other) rocks en route to the surface. It is demonstrated that this interaction is responsible for most of the CO{sub 2} in the Taupo Volcanic Zone (TVZ) geothermal systems. It is proposed that the modeling of this interaction might be accomplished by techniques similar to those used for the understanding of the oxygen isotope shift found in geothermal systems. The water rock interaction experiments of Ellis and Mahon (1964, 1967) provides some data on the kinetic rates for B and Cl dissolution from rocks likely to be encountered in the geothermal system, but further information on the behavior of B may be needed. If these problems can be overcome this modeling technique has promise for the estimation of the recharge of geothermal systems and hence the sustainability of these systems.

  11. Local dynamics of a fast-evolving sex-ratio system in Drosophila simulans.

    PubMed

    Bastide, Hlose; Grard, Pierre R; Ogereau, David; Cazemajor, Michel; Montchamp-Moreau, Catherine

    2013-11-01

    By distorting Mendelian transmission to their own advantage, X-linked meiotic drive elements can rapidly spread in natural populations, generating a sex-ratio bias. One expected consequence is the triggering of a co-evolutionary arms race between the sex chromosome that carries the distorter and suppressors counteracting its effect. Such an arms race has been theoretically and experimentally established and can have many evolutionary consequences. However, its dynamics in contemporary populations is still poorly documented. Here, we investigate the fate of the young X-linked Paris driver in Drosophila simulans from sub-Saharan Africa to the Middle East. We provide the first example of the early dynamics of distorters and suppressors: we find consistent evidence that the driving chromosomes have been rising in the Middle East during the last decade. In addition, identical haplotypes are at high frequencies around the two co-evolving drive loci in remote populations, implying that the driving X chromosomes share a recent common ancestor and suggesting that East Africa could be the cradle of the Paris driver. The segmental duplication associated with drive presents an unusual structure in West Africa, which could reflect a secondary state of the driver. Together with our previous demonstration of driver decline in the Indian Ocean where suppression is complete, these data provide a unique picture of the complex dynamics of a co-evolutionary arms race currently taking place in natural populations of D. simulans. PMID:24118375

  12. DEEP, LOW MASS RATIO OVERCONTACT BINARY SYSTEMS. XIII. DZ PISCIUM WITH INTRINSIC LIGHT VARIABILITY

    SciTech Connect

    Yang, Y.-G.; Dai, H.-F.; Qian, S.-B.; Soonthornthum, B. E-mail: qsb@ynao.ac.cn

    2013-08-01

    New multi-color photometry for the eclipsing binary DZ Psc was performed in 2011 and 2012 using the 85 cm telescope at the Xinglong Station of the National Astronomical Observatories of China. Using the updated Wilson-Devinney (W-D) code, we deduced two sets of photometric solutions. The overcontact degree is f = 89.7({+-} 1.0)%, identifying DZ Psc as a deep, low mass ratio overcontact binary. The asymmetric light curves (i.e., LC{sub 2} in 2012) were modeled by a hot spot on the primary star. Based on all of the available light minimum times, we discovered that the orbital period of DZ Psc may be undergoing a secular period increase with a cyclic variation. The modulated period and semi-amplitude of this oscillation are P{sub mod} = 11.89({+-} 0.19) yr and A = 0.0064({+-} 0.0006) days, which may be possibly attributed to either cyclic magnetic activity or light-time effect due to the third body. The long-term period increases at a rate of dP/dt=+7.43({+-}0.17) Multiplication-Sign 10{sup -7} days yr{sup -1}, which may be interpreted as conserved mass transfer from the less massive component to the more massive one. With mass transferring, DZ Psc will finally merge into a rapid-rotation single star when J{sub spin}/J{sub orb} > 1/3.

  13. California bearing ratio behavior of soil-stabilized class F fly ash systems

    SciTech Connect

    Leelavathamma, B.; Mini, K.M.; Pandian, N.S.

    2005-11-01

    Fly ash is a finely divided mineral residue resulting from the combustion of coal in power plants that occupies large extents of land and also causes environmental problems. Hence, concerted attempts are being made to effectively use fly ash in an environmentally friendly way instead of dumping. Several studies have been carried out for its bulk utilization, such as its addition to improve the California bearing ratio (CBR) of soil in roads and embankments. But a thorough mixing of fly ash with soil may not be possible in the field. Hence a study has been carried out on the CBR behavior of black cotton soil and Raichur fly ash (which is class F) in layers and compared with the same in mixes. The results show that the CBR values of soil-fly ash mixes are better than layers, as expected. To improve the strength of layers, cement is used as an additive to fly ash. The results show that black cotton soil can be improved with stabilized fly ash, solving its strength problem as well as the disposal problem of fly ash.

  14. Dynamics of counterpropagating waves in parametrically forced, large aspect ratio, nearly conservative systems with nonzero detuning

    NASA Astrophysics Data System (ADS)

    Vega, Jos M.; Knobloch, Edgar

    2003-07-01

    The dynamics of parametrically driven, slowly varying counterpropagating wave trains in nearly conservative systems are considered. The system is assumed to be invariant under reflection and translations in one direction, and periodic boundary conditions with period L are imposed, with L large but not too large in order that the effect of detuning be significant. The dynamics near the minima of the resulting resonance tongues are described by a system of coupled nonlocal Schrdinger equations with damping and parametric forcing. Elsewhere the long time behavior of the system is described by a damped complex Duffing equation with real coefficients, whose solutions relax to spatially uniform standing waves. Near the bicritical points where two adjacent resonance tongues intersect a pair of coupled damped complex Duffing equations captures the properties of both pure and mixed modes, and of the periodic solutions resulting from a Hopf bifurcation on the branch of mixed modes. As an application, we consider a Faraday system in an annulus in which a pair of counterpropagating surface gravity-capillary waves are excited parametrically by vertical vibration of the container, including the mean flow driven by time-averaged Reynolds stresses due to oscillatory viscous boundary layers along the bottom and the free surface. This mean flow is shown to have a large effect near the bicritical point, where the mean flow changes the dynamics of the system both quantitatively and qualitatively. In particular, inclusion of the mean flow permits Hopf bifurcations from the branches of pure standing waves, and parity-breaking bifurcations from mixed modes.

  15. Review of the design and performance features of hvdc systems connected to low short circuit ratio ac systems

    SciTech Connect

    Thallam, R.S. )

    1992-10-01

    The design and performance of an HVdc system is significantly impacted by the relative strength of the ac system to which it is connected. In this paper, design and performance features of ten HVdc systems are discussed. All of these systems are connected to ac systems that are relatively weak compared to the rating of the dc system. Six of these systems are back-to-back, two are overhead lines, and two are undersea cable connections. AC and dc system interaction problems and how they are addressed in the design and specification of each of these systems, are described.

  16. Evaluation of the water-effect ratio procedure for metals in a riverine system

    SciTech Connect

    Diamond, J.M.; Koplish, D.E.; McMahon, J. III; Rost, R.

    1997-03-01

    Site-specific metal standards were determined for a part of the lower Lehigh River using the US Environmental Protection Agency`s water-effect ratio (WER) procedure. The WERs were based on laboratory and site water testing of the species Ceriodaphnia dubia and Pimephales promelas (fathead minnow) and five metals (copper, cadmium, lead, silver, and zinc) during four different months. Both species generally exhibited similar patterns in WERs. The greatest variability between the two species was observed for copper, silver, and lead. Ceriodaphnia yielded a lower mean WER than the fathead minnow for lead and zinc and WERs similar to those of the fathead minnow for copper, cadmium, and silver. The species more sensitive to a given metal did not always exhibit a higher WER, as had been previously assumed. A comparison of final WER calculations indicated that the geometric mean WER was typically higher than the final WER obtained using the 1994 guidance. For most metals, site water toxicity was reduced due to nonacutely toxic dissolved metal. Copper yielded the highest final WER regardless of the calculation method used. Regression analyses indicated that the copper WER was directly related, and the cadmium WER inversely related, to effluent concentration. Copper, lead, and silver WERs were related to site water pH. Cadmium and lead WERs were related to pH and dissolved solids. Zinc WERs were unrelated to any of the water quality variables measured and were similar among site water samples. The results suggest it is prudent to use two species in WER testing and different site water samples to derive a final WER, particularly at sites that are not effluent dominated.

  17. Selenium stable isotope ratios in California agricultural drainage water management systems.

    PubMed

    Herbel, Mitchell J; Johnson, Thomas M; Tanji, Kenneth K; Gao, Suduan; Bullen, Thomas D

    2002-01-01

    Selenium stable isotope ratios are known to shift in predictable ways during various microbial, chemical, and biological processes, and can be used to better understand Se cycling in contaminated environments. In this study we used Se stable isotopes to discern the mechanisms controlling the transformation of oxidized, aqueous forms of Se to reduced, insoluble forms in sediments of Se-affected environments. We measured 80Se/76Se in surface waters, shallow ground waters, evaporites, digested plants and sediments, and sequential extracts from several sites where agricultural drainage water is processed in the San Joaquin Valley of California. Selenium isotope analyses of samples obtained from the Tulare Lake Drainage District flow-through wetland reveal small isotopic contrasts (mean difference 0.7%) between surface water and reduced Se species in the underlying sediments. Selenium in aquatic macrophytes was very similar isotopically to the NaOH and Na2SO3 sediment extracts designed to recover soluble organic Se and Se(0), respectively. For the integrated on-farm drainage management sites, evaporite salts were slightly (approximately 0.6%) enriched in the heavier isotope relative to the inferred parent waters, whereas surface soils were slightly (approximately 1.4%) depleted. Bacterial or chemical reduction of Se(VI) or Se(IV) may be occurring at these sites, but the small isotopic contrasts suggest that other, less isotopically fractionating mechanisms are responsible for accumulation of reduced forms in the sediments. These findings provide evidence that Se assimilation by plants and algae followed by deposition and mineralization is the dominant transformation pathway responsible for accumulation of reduced forms of Se in the wetland sediments. PMID:12175032

  18. Selenium stable isotope ratios in California agricultural drainage water management systems

    USGS Publications Warehouse

    Herbel, M.J.; Johnson, T.M.; Tanji, K.K.; Gao, S.; Bullen, T.D.

    2002-01-01

    Selenium stable isotope ratios are known to shift in predictable ways during various microbial, chemical, and biological processes, and can be used to better understand Se cycling in contaminated environments. In this study we used Se stable isotopes to discern the mechanisms controlling the transformation of oxidized, aqueous forms of Se to reduced, insoluble forms in sediments of Se-affected environments. We measured 80Se/76Se in surface waters, shallow ground waters, evaporites, digested plants and sediments, and sequential extracts from several sites where agricultural drainage water is processed in the San Joaquin Valley of California. Selenium isotope analyses of samples obtained from the Tulare Lake Drainage District flow-through wetland reveal small isotopic contrasts (mean difference 0.7%o) between surface water and reduced Se species in the underlying sediments. Selenium in aquatic macrophytes was very similar isotopically to the NaOH and Na2SO3 sediment extracts designed to recover soluble organic Se and Se(O), respectively. For the integrated on-farm drainage management sites, evaporite salts were slightly (approximately 0.6%o) enriched in the heavier isotope relative to the inferred parent waters, whereas surface soils were slightly (approximately 1.4%o) depleted. Bacterial or chemical reduction of Se(VI) or Se(IV) may be occurring at these sites, but the small isotopic contrasts suggest that other, less isotopically fractionating mechanisms are responsible for accumulation of reduced forms in the sediments. These findings provide evidence that Se assimilation by plants and algae followed by deposition and mineralization is the dominant transformation pathway responsible for accumulation of reduced forms of Se in the wetland sediments.

  19. Sedimentary Sulphur:Iron Ratio Indicates Vivianite Occurrence: A Study from Two Contrasting Freshwater Systems

    PubMed Central

    Rothe, Matthias; Kleeberg, Andreas; Grüneberg, Björn; Friese, Kurt; Pérez-Mayo, Manuel; Hupfer, Michael

    2015-01-01

    An increasing number of studies constrain the importance of iron for the long-term retention of phosphorus (P) under anoxic conditions, i.e. the formation of reduced iron phosphate minerals such as vivianite (Fe3(PO4)2⋅8H2O). Much remains unknown about vivianite formation, the factors controlling its occurrence, and its relevance for P burial during early sediment diagenesis. To study the occurrence of vivianite and to assess its relevance for P binding, surface sediments of two hydrologically contrasting waters were analysed by heavy-liquid separation and subsequent powder X-ray diffraction. In Lake Arendsee, vivianite was present in deeper sediment horizons and not in the uppermost layers with a sharp transition between vivianite and non-vivianite bearing layers. In contrast, in lowland river Lower Havel vivianite was present in the upper sediment layers and not in deeper horizons with a gradual transition between non-vivianite and vivianite bearing layers. In both waters, vivianite occurrence was accompanied by the presence of pyrite (FeS2). Vivianite formation was favoured by an elevated iron availability through a lower degree of sulphidisation and was present at a molar ratio of total sulphur to reactive iron smaller than 1.1, only. A longer lasting burden of sediments by organic matter, i.e. due to eutrophication, favours the release of sulphides, and the formation of insoluble iron sulphides leading to a lack of available iron and to less or no vivianite formation. This weakening in sedimentary P retention, representing a negative feedback mechanism (P release) in terms of water quality, could be partly compensated by harmless Fe amendments. PMID:26599406

  20. Closed system respirometry may underestimate tissue gas exchange and bias the respiratory exchange ratio (RER).

    PubMed

    Malte, Christian Lind; Nørgaard, Simon; Wang, Tobias

    2016-02-01

    Closed respirometry is a commonly used method to measure gas exchange in animals due to its apparent simplicity. Typically, the rates of O2 uptake and CO2 excretion (V˙O2 and V˙CO2, respectively) are assumed to be in steady state, such that the measured rates of gas exchange equal those at tissue level. In other words, the respiratory gas exchange ratio (RER) is assumed to equal the respiratory quotient (RQ). However, because the gas concentrations change progressively during closure, the animal inspires air with a progressively increasing CO2 concentration and decreasing O2 concentration. These changes will eventually affect gas exchange causing the O2 and CO2 stores within the animal to change. Because of the higher solubility/capacitance of CO2 in the tissues of the body, V˙CO2 will be more affected than V˙O2, and we hypothesize therefore that RER will become progressively underestimated as closure time is prolonged. This hypothesis was addressed by a combination of experimental studies involving closed respirometry on ball pythons (Python regius) as well as mathematical models of gas exchange. We show that increased closed duration of the respirometer reduces RER by up to 13%, and these findings may explain previous reports of RER values being below 0.7. Our model reveals that the maximally possible reduction in RER is determined by the storage capacity of the body for CO2 (product of size and specific capacitance) relative to the respirometer storage capacity. Furthermore, modeling also shows that pronounced ventilatory and circulatory response to hypercapnia can alleviate the reduction in RER. PMID:26523499

  1. Row Ratios of Intercropping Maize and Soybean Can Affect Agronomic Efficiency of the System and Subsequent Wheat

    PubMed Central

    Zhang, Yitao; Liu, Jian; Zhang, Jizong; Liu, Hongbin; Liu, Shen; Zhai, Limei; Wang, Hongyuan; Lei, Qiuliang; Ren, Tianzhi; Yin, Changbin

    2015-01-01

    Intercropping is regarded as an important agricultural practice to improve crop production and environmental quality in the regions with intensive agricultural production, e.g., northern China. To optimize agronomic advantage of maize (Zea mays L.) and soybean (Glycine max L.) intercropping system compared to monoculture of maize, two sequential experiments were conducted. Experiment 1 was to screening the optimal cropping system in summer that had the highest yields and economic benefits, and Experiment 2 was to identify the optimum row ratio of the intercrops selected from Experiment 1. Results of Experiment 1 showed that maize intercropping with soybean (maize || soybean) was the optimal cropping system in summer. Compared to conventional monoculture of maize, maize || soybean had significant advantage in yield, economy, land utilization ratio and reducing soil nitrate nitrogen (N) accumulation, as well as better residual effect on the subsequent wheat (Triticum aestivum L.) crop. Experiment 2 showed that intercropping systems reduced use of N fertilizer per unit land area and increased relative biomass of intercropped maize, due to promoted photosynthetic efficiency of border rows and N utilization during symbiotic period. Intercropping advantage began to emerge at tasseling stage after N topdressing for maize. Among all treatments with different row ratios, alternating four maize rows with six soybean rows (4M:6S) had the largest land equivalent ratio (1.30), total N accumulation in crops (258 kg ha-1), and economic benefit (3,408 USD ha-1). Compared to maize monoculture, 4M:6S had significantly lower nitrate-N accumulation in soil both after harvest of maize and after harvest of the subsequent wheat, but it did not decrease yield of wheat. The most important advantage of 4M:6S was to increase biomass of intercropped maize and soybean, which further led to the increase of total N accumulation by crops as well as economic benefit. In conclusion, alternating four maize rows with six soybean rows was the optimum row ratio in maize || soybean system, though this needs to be further confirmed by pluri-annual trials. PMID:26061566

  2. Row Ratios of Intercropping Maize and Soybean Can Affect Agronomic Efficiency of the System and Subsequent Wheat.

    PubMed

    Zhang, Yitao; Liu, Jian; Zhang, Jizong; Liu, Hongbin; Liu, Shen; Zhai, Limei; Wang, Hongyuan; Lei, Qiuliang; Ren, Tianzhi; Yin, Changbin

    2015-01-01

    Intercropping is regarded as an important agricultural practice to improve crop production and environmental quality in the regions with intensive agricultural production, e.g., northern China. To optimize agronomic advantage of maize (Zea mays L.) and soybean (Glycine max L.) intercropping system compared to monoculture of maize, two sequential experiments were conducted. Experiment 1 was to screening the optimal cropping system in summer that had the highest yields and economic benefits, and Experiment 2 was to identify the optimum row ratio of the intercrops selected from Experiment 1. Results of Experiment 1 showed that maize intercropping with soybean (maize || soybean) was the optimal cropping system in summer. Compared to conventional monoculture of maize, maize || soybean had significant advantage in yield, economy, land utilization ratio and reducing soil nitrate nitrogen (N) accumulation, as well as better residual effect on the subsequent wheat (Triticum aestivum L.) crop. Experiment 2 showed that intercropping systems reduced use of N fertilizer per unit land area and increased relative biomass of intercropped maize, due to promoted photosynthetic efficiency of border rows and N utilization during symbiotic period. Intercropping advantage began to emerge at tasseling stage after N topdressing for maize. Among all treatments with different row ratios, alternating four maize rows with six soybean rows (4M:6S) had the largest land equivalent ratio (1.30), total N accumulation in crops (258 kg ha(-1)), and economic benefit (3,408 USD ha(-1)). Compared to maize monoculture, 4M:6S had significantly lower nitrate-N accumulation in soil both after harvest of maize and after harvest of the subsequent wheat, but it did not decrease yield of wheat. The most important advantage of 4M:6S was to increase biomass of intercropped maize and soybean, which further led to the increase of total N accumulation by crops as well as economic benefit. In conclusion, alternating four maize rows with six soybean rows was the optimum row ratio in maize || soybean system, though this needs to be further confirmed by pluri-annual trials. PMID:26061566

  3. 36Cl/Cl ratios in geothermal systems: preliminary measurements from the Coso Field

    SciTech Connect

    Nimz, G.J.; Moore, J.N.; Kasameyer, P.W.

    1997-07-01

    The {sub 36}Cl/Cl isotopic composition of chlorine in geothermal systems can be a useful diagnostic tool in characterizing hydrologic structure, in determining the origins and age of waters within the systems, and in differentiating the sources of chlorine (and other solutes) in the thermal waters. The {sub 36}Cl/Cl values for several geothermal water samples and reservoir host rock samples from the Coso, California geothermal field have been measured for these purposes. The results indicate that most of the chlorine is not derived from the dominant granitoid that host the geothermal system. If the chlorine was originally input into the Coso subsurface through meteoric recharge, that input occurred at least 1-1.25 million years ago. The results suggest that the thermal waters could be connate waters derived from sedimentary formations, presumably underlying and adjacent top the granitic rocks, which have recently migrated into the host rocks. Alternatively, most of the chlorine but not the water, may have recently input into the system from magmatic sources. In either case, the results indicate that most of the chlorine in the thermal waters has existed within the granitoid host rocks for no more than about 100,00-200,00 years. this residence time for the chlorine is similar to residence times suggested by other researchers for chlorine in deep groundwaters of the Mono Basin north of the Coso field.

  4. RELATIONSHIP BETWEEN HVAC SYSTEM OPERATION, AIR EXCHANGE RATE, AND INDOOR-OUTDOOR PARTICULATE MATTER RATIOS

    EPA Science Inventory

    Measurements of duty cycle , the fraction of time the heating and cooling (HVAC) system was operating, were made in each participant's home during the spring season of the RTP Particulate Matter Panel Study. A miniature temperature sensor/data logger combination placed on the ...

  5. Peak-to-average power ratio reduction in all-optical orthogonal frequency division multiplexing system using rotated constellation approach

    NASA Astrophysics Data System (ADS)

    Hmood, Jassim K.; Noordin, Kamarul A.; Arof, Hamzah; Harun, Sulaiman W.

    2015-10-01

    In this paper, a new approach for reducing peak-to-average power ratio (PAPR) based on modulated half subcarriers in all-optical OFDM systems with rotated QAM constellation is presented. To reduce the PAPR, the odd subcarriers are modulated with rotated QAM constellation, while the even subcarriers are modulated with standard QAM constellation. The impact of the rotation angle on the PAPR is mathematically modeled. The effect of PAPR reduction on the system performance is investigated by simulating the all-optical OFDM system, which uses optical coupler-based inverse fast Fourier transform (IFFT)/fast Fourier transform (FFT). The all-optical system is numerically demonstrated with 29 subcarriers. Each subcarrier is modulated by a QAM modulator at a symbol rate of 25 Gsymbol/s. The results reveal that PAPR is reduced with increasing the angle of rotation. The PAPR reduction can reach about 0.8 dB when the complementary cumulative distribution function (CCDF) is 1 10-3. Furthermore, both the nonlinear phase noise and the optical signal-to-noise ratio (OSNR) of the system are improved in comparison with the original all-optical OFDM without PAPR reduction.

  6. Structure of Rapidly Quenched Fe-Co-Sn-B Systems with Varying Fe/Co Ratio

    NASA Astrophysics Data System (ADS)

    Janotov, Irena; vec, Peter; Mat'ko, Igor; vec, Peter; Jani?kovi?, Duan; Zigo, Juraj

    2015-09-01

    We present a study of ferromagnetic systems based on Fe-Co-Sn-B in nanocrystalline state. Interesting magnetic properties potentially are given by the homogeneous and ultrafine structure of bcc Fe grains in amorphous structure. The effect of alloying by Sn improves the properties of resulting structure constituted be crystalline grains in amorphous matrix. The structure transformation from amorphous state was investigated by selected techniques of thermal analysis and the resulting phase and morphology of crystalline products were analyzed.

  7. CONSTRAINING MASS RATIO AND EXTINCTION IN THE FU ORIONIS BINARY SYSTEM WITH INFRARED INTEGRAL FIELD SPECTROSCOPY

    SciTech Connect

    Pueyo, Laurent; Hillenbrand, Lynne; Hinkley, Sasha; Dekany, Richard; Roberts, Jenny; Vasisht, Gautam; Roberts, Lewis C. Jr.; Shao, Mike; Burruss, Rick; Cady, Eric; Oppenheimer, Ben R.; Brenner, Douglas; Zimmerman, Neil; Monnier, John D.; Crepp, Justin; Parry, Ian; Beichman, Charles; Soummer, Remi

    2012-09-20

    We report low-resolution near-infrared spectroscopic observations of the eruptive star FU Orionis using the Integral Field Spectrograph (IFS) Project 1640 installed at the Palomar Hale telescope. This work focuses on elucidating the nature of the faint source, located 0.''5 south of FU Ori, and identified in 2003 as FU Ori S. We first use our observations in conjunction with published data to demonstrate that the two stars are indeed physically associated and form a true binary pair. We then proceed to extract J- and H-band spectro-photometry using the damped LOCI algorithm, a reduction method tailored for high contrast science with IFS. This is the first communication reporting the high accuracy of this technique, pioneered by the Project 1640 team, on a faint astronomical source. We use our low-resolution near-infrared spectrum in conjunction with 10.2 {mu}m interferometric data to constrain the infrared excess of FU Ori S. We then focus on estimating the bulk physical properties of FU Ori S. Our models lead to estimates of an object heavily reddened, A{sub V} = 8-12, with an effective temperature of {approx}4000-6500 K. Finally, we put these results in the context of the FU Ori N-S system and argue that our analysis provides evidence that FU Ori S might be the more massive component of this binary system.

  8. Vasopressin decreases pulmonary-to-systemic vascular resistance ratio in a porcine model of severe hemorrhagic shock.

    PubMed

    Sarkar, Joy; Golden, Patrick J; Kajiura, Lauren N; Murata, Lee-Ann M; Uyehara, Catherine F T

    2015-05-01

    Vasopressors are gaining renewed interest as treatment adjuncts in hemorrhagic shock. The ideal vasoconstrictor will increase systemic blood pressure without increasing pulmonary vascular resistance (PVR), which hinders pulmonary perfusion and exacerbates hypoxemia. However, the selectivity of pressors for pulmonary versus systemic vasoconstriction during hemorrhage has not been characterized. The purpose of this study was to test the hypothesis that vasopressin (VP) has distinct effects on pulmonary versus systemic hemodynamics, unlike the catecholamine vasopressors norepinephrine (NE) and phenylephrine (PE). Anesthetized and ventilated pigs were assigned to resuscitation with saline only (n = 7) or saline with VP (n = 6), NE (n = 6), or PE (n = 6). Animals were hemorrhaged to a target volume of 30 mL/kg and a mean arterial pressure of 35 mmHg. One hour after the start of hemorrhage, animals were resuscitated with saline up to one shed blood volume, followed by either additional saline or a vasopressor. Hemodynamics and oxygenation were measured hourly for 4 h after the start of hemorrhage. Vasopressin increased systemic vascular resistance (SVR) while sparing the pulmonary vasculature, leading to a 45% decrease in the PVR/SVR ratio compared with treatment with PE. Conversely, NE induced pulmonary hypertension and led to an increased PVR/SVR ratio associated with decreased oxygen saturation. Phenylephrine and crystalloid had no significant effect on the PVR/SVR ratio. Sparing of pulmonary vasoconstriction occurs only with VP, not with administration of crystalloid or catecholamine pressors. The ability of VP to maintain blood oxygenation indicates that VP may prevent hypoxemia in the management of hemorrhagic shock. PMID:25565637

  9. Direct-drive high-convergence-ratio implosion studies on the OMEGA laser system

    SciTech Connect

    Marshall, F. J.; Delettrez, J. A.; Epstein, R.; Glebov, V. Yu.; Harding, D. R.; McKenty, P. W.; Meyerhofer, D. D.; Radha, P. B.; Seka, W.; Skupsky, S.

    2000-05-01

    A series of direct-drive implosion experiments, using room-temperature, gas-filled CH targets, are performed on the University of Rochester's OMEGA laser system [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)]. The target performance at stagnation and its dependence on beam smoothing and pulse shaping is investigated. Compressed core conditions are diagnosed using x-ray and neutron spectroscopy, and x-ray imaging. The individual beams of OMEGA are smoothed by spectral dispersion in two dimensions (2D SSD) with laser bandwidths up to {approx}0.3 THz, with 1 ns square to 2.5 ns shaped pulses. A clear dependence of target performance on pulse shape and beam smoothing is seen, with the target performance (yield, areal density, and shell integrity) improving as SSD bandwidth is applied. (c)

  10. Development of Polymer Gel Systems to Improve Volumetric Sweep and Reduce Producing Water/Oil Ratios

    SciTech Connect

    G. Paul Willhite; Stan McCool; Don W. Green; Min Cheng; Feiyan Chen

    2005-04-03

    Gelled polymer treatments are applied to oil reservoirs to increase oil production and to reduce water production by altering the fluid movement within the reservoir. This report describes the results of the third year of a 42 month research program that is aimed at an understanding of gelation chemistry and the fundamental mechanisms that alter the flows of oil and water in reservoir rocks after a gel treatment. Work focused on a widely applied system in the field, the partially hydrolyzed polyacrylamide-chromium acetate gel. Gelation occurs by network formation through the crosslinking of polyacrylamide molecules as a result of reaction with chromium acetate. Pre-gel aggregates form and grow as reactions between chromium acetate and polyacrylamide proceed. A mathematical model that describes uptake and crosslinking reactions as a function of time was derived. The model was probability based and provides molecular-weight averages and molecular-weight distributions of the pre-gel aggregates as a function of time and initial system conditions. A liquid chromatography apparatus to experimentally measure the size and molecular weight distributions of polymer samples was developed. The method worked well for polymer samples without the chromium crosslinker. Sample retention observed during measurements of gelant samples during the gelation process compromised the results. Other methods will be tested to measure size distributions of the pre-gel aggregates. Dissolution of carbonate minerals during the injection of gelants causes the pH of the gelant to increase. Chromium precipitates from solution at the higher pH values robbing the gelant of crosslinker. Experimental data on the transport of chromium acetate solutions through dolomite cores were obtained. A mathematical model that describes the transport of brine and chromium acetate solutions through rocks containing carbonate minerals was used to simulate the experimental results.

  11. Mechanical Design of High Lift Systems for High Aspect Ratio Swept Wings

    NASA Technical Reports Server (NTRS)

    Rudolph, Peter K. C.

    1998-01-01

    The NASA Ames Research Center is working to develop a methodology for the optimization and design of the high lift system for future subsonic airliners with the involvement of two partners. Aerodynamic analysis methods for two dimensional and three dimensional wing performance with flaps and slats deployed are being developed through a grant with the aeronautical department of the University of California Davis, and a flap and slat mechanism design procedure is being developed through a contract with PKCR, Inc., of Seattle, WA. This report documents the work that has been completed in the contract with PKCR on mechanism design. Flap mechanism designs have been completed for seven (7) different mechanisms with a total of twelve (12) different layouts all for a common single slotted flap configuration. The seven mechanisms are as follows: Simple Hinge, Upside Down/Upright Four Bar Linkage (two layouts), Upside Down Four Bar Linkages (three versions), Airbus A330/340 Link/Track Mechanism, Airbus A320 Link/Track Mechanism (two layouts), Boeing Link/Track Mechanism (two layouts), and Boeing 767 Hinged Beam Four Bar Linkage. In addition, a single layout has been made to investigate the growth potential from a single slotted flap to a vane/main double slotted flap using the Boeing Link/Track Mechanism. All layouts show Fowler motion and gap progression of the flap from stowed to a fully deployed position, and evaluations based on spanwise continuity, fairing size and number, complexity, reliability and maintainability and weight as well as Fowler motion and gap progression are presented. For slat design, the options have been limited to mechanisms for a shallow leading edge slat. Three (3) different layouts are presented for maximum slat angles of 20 deg, 15 deg and 1O deg all mechanized with a rack and pinion drive similar to that on the Boeing 757 airplane. Based on the work of Ljungstroem in Sweden, this type of slat design appears to shift the lift curve so that higher lift is achieved with the deployed slat with no increase in angle of attack. The layouts demonstrate that these slat systems can be designed with no need for slave links, and an experimental test program is outlined to experimentally validate the lift characteristics of the shallow slat.

  12. A five-collector system for the simultaneous measurement of argon isotope ratios in a static mass spectrometer

    USGS Publications Warehouse

    Stacey, J.S.; Sherrill, N.D.; Dalrymple, G.B.; Lanphere, M.A.; Carpenter, N.V.

    1981-01-01

    A system is described that utilizes five separate Faraday-cup collector assemblies, aligned along the focal plane of a mass spectrometer, to collect simultaneous argon ion beams at masses 36-40. Each collector has its own electrometer amplifier and analog-to-digital measuring channel, the outputs of which are processed by a minicomputer that also controls the mass spectrometer. The mass spectrometer utilizes a 90?? sector magnetic analyzer with a radius of 23 cm, in which some degree of z-direction focussing is provided for all the ion beams by the fringe field of the magnet. Simultaneous measurement of the ion beams helps to eliminate mass-spectrometer memory as a significant source of measurement error during an analysis. Isotope ratios stabilize between 7 and 9 s after sample admission into the spectrometer, and thereafter changes in the measured ratios are linear, typically to within ??0.02%. Thus the multi-collector arrangement permits very short extrapolation times for computation of initial ratios, and also provides the advantages of simultaneous measurement of the ion currents in that errors due to variations in ion beam intensity are minimized. A complete analysis takes less than 10 min, so that sample throughput can be greatly enhanced. In this instrument, the factor limiting analytical precision now lies in short-term apparent variations in the interchannel calibration factors. ?? 1981.

  13. Strontium concentrations and isotope ratios in a forest-river system in the South Qinling Mts., China.

    PubMed

    Bu, Hongmei; Song, Xianfang; Zhang, Quanfa; Burford, Michele A

    2016-04-15

    The concentrations of dissolved strontium (Sr) and isotope ratios ((87)Sr/(86)Sr) in rainwater, river water, and water from forest soil are measured to investigate the contributions of these sources to a river during base flow conditions in the relatively pristine South Qinling Mountains, China. Dissolved Sr concentrations and (87)Sr/(86)Sr ratios vary significantly between different water types (p < 0.01) suggesting that it is suitable for differentiating sources. Dissolved Sr is also positively correlated with most ions and a range of physicochemical parameters (p < 0.01 and p < 0.05 respectively) in water samples including Ca(2+), Mg(2+), EC, and TDS (p < 0.001) indicating their similarities in the drivers of biogeochemical processes and common origins. The correlations between Sr isotopes and Ca/Na, Ca/K, and 1000/Sr ratios suggest that three end-members of atmospheric inputs, carbonate and silicate weathering control the Sr water chemistry in the river water. Using the three-source mixing model, atmospheric inputs, carbonate, and silicate weathering contribute 74%, 20%, and 6% respectively to the dissolved Sr in the river water. This research has provided new insights into the contribution of sources of Sr to a river system in a mountainous catchment. PMID:26900970

  14. Compact point-detection fluorescence spectroscopy system for quantifying intrinsic fluorescence redox ratio in brain cancer diagnostics

    NASA Astrophysics Data System (ADS)

    Liu, Quan; Grant, Gerald; Li, Jianjun; Zhang, Yan; Hu, Fangyao; Li, Shuqin; Wilson, Christy; Chen, Kui; Bigner, Darell; Vo-Dinh, Tuan

    2011-03-01

    We report the development of a compact point-detection fluorescence spectroscopy system and two data analysis methods to quantify the intrinsic fluorescence redox ratio and diagnose brain cancer in an orthotopic brain tumor rat model. Our system employs one compact cw diode laser (407 nm) to excite two primary endogenous fluorophores, reduced nicotinamide adenine dinucleotide, and flavin adenine dinucleotide. The spectra were first analyzed using a spectral filtering modulation method developed previously to derive the intrinsic fluorescence redox ratio, which has the advantages of insensitivty to optical coupling and rapid data acquisition and analysis. This method represents a convenient and rapid alternative for achieving intrinsic fluorescence-based redox measurements as compared to those complicated model-based methods. It is worth noting that the method can also extract total hemoglobin concentration at the same time but only if the emission path length of fluorescence light, which depends on the illumination and collection geometry of the optical probe, is long enough so that the effect of absorption on fluorescence intensity due to hemoglobin is significant. Then a multivariate method was used to statistically classify normal tissues and tumors. Although the first method offers quantitative tissue metabolism information, the second method provides high overall classification accuracy. The two methods provide complementary capabilities for understanding cancer development and noninvasively diagnosing brain cancer. The results of our study suggest that this portable system can be potentially used to demarcate the elusive boundary between a brain tumor and the surrounding normal tissue during surgical resection.

  15. Development of Polymer Gel Systems to Improve Volumetric Sweep and Reduce Producing Water/Oil Ratios

    SciTech Connect

    G. Paul Willhite; Stan McCool; Don W. Green; Min Cheng; Feiyan Chen

    2005-12-31

    Gelled polymer treatments are applied to oil reservoirs to increase oil production and to reduce water production by altering the fluid movement within the reservoir. This report describes the results of a 42-month research program that focused on the understanding of gelation chemistry and the fundamental mechanisms that alter the flows of oil and water in reservoir rocks after a gel treatment. Work was conducted on a widely applied system in the field, the partially hydrolyzed polyacrylamide-chromium acetate gel. Gelation occurs by network formation through the crosslinking of polyacrylamide molecules as a result of reaction with chromium acetate. Pre-gel aggregates form and grow as reactions between chromium acetate and polyacrylamide proceed. A rate equation that describes the reaction between chromium acetate and polymer molecules was regressed from experimental data. A mathematical model that describes the crosslinking reaction between two polymer molecules as a function of time was derived. The model was based on probability concepts and provides molecular-weight averages and molecular-weight distributions of the pre-gel aggregates as a function of time and initial system conditions. Average molecular weights of pre-gel aggregates were measured as a function of time and were comparable to model simulations. Experimental methods to determine molecular weight distributions of pre-gel aggregates were unsuccessful. Dissolution of carbonate minerals during the injection of gelants causes the pH of the gelant to increase. Chromium precipitates from solution at the higher pH values robbing the gelant of crosslinker. Experimental data on the transport of chromium acetate solutions through dolomite cores were obtained. A mathematical model that describes the transport of brine and chromium acetate solutions through rocks containing carbonate minerals was used to simulate the experimental results and data from literature. Gel treatments usually reduce the permeability to water to a greater extent than the permeability to oil is reduced. This phenomenon is referred to as disproportionate permeability reduction (DPR). Flow experiments were conducted in sandpacks to determine the effect of polymer and chromium concentrations on DPR. All gels studied reduced the permeability to water by a greater factor than the factor by which the oil permeability was reduced. Greater DPR was observed as the concentrations of polymer and chromium were increased. A conceptual model of the mechanisms responsible for DPR is presented. Primary features of the model are (1) the development of flow channels through the gel by dehydration and displacement of the gel and by re-connection of pre-treatment, residual oil volume and (2) high flow resistance in the channels during water flow is caused by significant saturations of oil remaining in the channels. A similar study of DPR was conducted in Berea sandstone cores. Both oil and water permeabilities were reduced by much smaller factors in Berea sandstone cores than in similar treatments in sandpacks. Poor maturation of the gelant in the Berea rock was thought to be caused by fluid-rock interactions that interfered with the gelation process.

  16. Identifying non-normal and lognormal characteristics of temperature, mixing ratio, surface pressure, and wind for data assimilation systems

    NASA Astrophysics Data System (ADS)

    Kliewer, A. J.; Fletcher, S. J.; Jones, A. S.; Forsythe, J. M.

    2015-09-01

    Data assimilation systems and retrieval systems that are based upon a maximum likelihood estimation, many of which are in operational use, rely on the assumption that all of the errors and variables involved follow a normal distribution. This work develops a series of statistical tests to show that mixing ratio, temperature, wind and surface pressure follow non-normal, or in fact, lognormal distributions thus impacting the design-basis of many operational data assimilation and retrieval systems. For this study one year of Global Forecast System 00:00 UTC 6 h forecast were analyzed using statistical hypothesis tests. The motivation of this work is to identify the need to resolve whether or not the assumption of normality is valid and to give guidance for where and when a data assimilation system or a retrieval system needs to adapt its cost function to the mixed normal-lognormal distribution-based Bayesian model. The statistical methods of detection are based upon Shapiro-Wilk, Jarque-Bera and a ?2 test, and a new composite indicator using all three measures. Another method of detection fits distributions to the temporal-based histograms of temperature, mixing ratio, and wind. The conclusion of this work is that there are persistent areas, times, and vertical levels where the normal assumption is not valid, and that the lognormal distribution-based Bayesian model is observationally justified to minimize the error for these conditions. The results herein suggest that comprehensive statistical climatologies may need to be developed to capture the non-normal traits of the 6 h forecast.

  17. Measurement and Evaluation of 3-D Structure in Low-Aspect-Ratio RFP RELAX with Dual SXR Imaging System

    NASA Astrophysics Data System (ADS)

    Sanpei, Akio; Nishimura, Kanae; Masamune, Sadao; Tanaka, Hiroyuki; Himura, Haruhiko; Ohdachi, Satoshi; Mizuguchi, Naoki; Akiyama, Tsuyoshi

    The high-speed soft X-ray (SXR) imaging system has been extended to take the images from tangential and vertical directions simultaneously to observe three-dimensional (3-D) dynamic structures of the SXR emissivity. A preliminary experimental resultin which we observed SXR images from the quasi-periodic quasi-single helicity (QSH) and multi-helicity (MH) states in low-aspect-ratio (low-A) reversed field pinch (RFP) plasmas is presented. Calculated magnetic configuration suggests existence of a large magnetic island in shallow reversal discharge.

  18. A Neuro-Fuzzy Inference System Combining Wavelet Denoising, Principal Component Analysis, and Sequential Probability Ratio Test for Sensor Monitoring

    SciTech Connect

    Na, Man Gyun; Oh, Seungrohk

    2002-11-15

    A neuro-fuzzy inference system combined with the wavelet denoising, principal component analysis (PCA), and sequential probability ratio test (SPRT) methods has been developed to monitor the relevant sensor using the information of other sensors. The parameters of the neuro-fuzzy inference system that estimates the relevant sensor signal are optimized by a genetic algorithm and a least-squares algorithm. The wavelet denoising technique was applied to remove noise components in input signals into the neuro-fuzzy system. By reducing the dimension of an input space into the neuro-fuzzy system without losing a significant amount of information, the PCA was used to reduce the time necessary to train the neuro-fuzzy system, simplify the structure of the neuro-fuzzy inference system, and also, make easy the selection of the input signals into the neuro-fuzzy system. By using the residual signals between the estimated signals and the measured signals, the SPRT is applied to detect whether the sensors are degraded or not. The proposed sensor-monitoring algorithm was verified through applications to the pressurizer water level, the pressurizer pressure, and the hot-leg temperature sensors in pressurized water reactors.

  19. DEVELOPMENT OF POLYMER GEL SYSTEMS TO IMPROVE VOLUMETRIC SWEEP AND REDUCE PRODUCING WATER/OIL RATIOS

    SciTech Connect

    G. Paul Willhite; Stan McCool; Don W. Green; Min Cheng; Rajeev Jain; Tuan Nguyen

    2003-11-01

    Gelled polymer treatments are applied to oil reservoirs to increase oil production and to reduce water production by altering the fluid movement within the reservoir. This report describes the results of the first year of a three-year research program that is aimed at the understanding of the chemistry of gelation and the fundamental mechanisms that alter the flows of oil and water in reservoir rocks after a gel treatment. Work has focused on a widely-applied system in field applications, the partially hydrolyzed polyacrylamide-chromium acetate gel. Gelation occurs by network formation through the crosslinking of polyacrylamide molecules as a result of reaction with chromium acetate. The initial reaction between chromium acetate and one polymer is referred to as the uptake reaction. The uptake reaction was studied as functions of chromium and polymer concentrations and pH values. Experimental data were regressed to determine a rate equation that describes the uptake reaction of chromium by polyacrylamide. Pre-gel aggregates form and grow as the reactions between chromium acetate and polyacrylamide proceed. A statistical model that describes the growth of pre-gel aggregates was developed using the theory of branching processes. The model gives molecular weight averages that are expressed as functions of the conversion of the reactive sites on chromium acetate or on the polymer molecule. Results of the application of the model correlate well with experimental data of viscosity and weight-average molecular weight and gives insights into the gelation process. A third study addresses the flow of water and oil in rock material after a gel treatment. Previous works have shown that gel treatments usually reduce the permeability to water to a greater extent than the permeability to oil is reduced. This phenomenon is referred to as disproportionate permeability reduction (DPR). Flow experiments were conducted to determine the effect of polymer and chromium concentrations on DPR. All gels studied reduced the permeability to water by a greater factor than the factor by which the oil permeability was reduced. Greater DPR was observed as the concentrations of polymer and chromium were increased. Increased pressure gradients during oil flow decreased the oil permeability and the water permeability that was measured afterward. Lower pressure gradients that were applied subsequently moderately affected water permeabilities but did not affect oil permeabilities. A conceptual model of the mechanisms responsible for DPR is presented. Primary features of the model are (1) the development of flow channels through the gel by dehydration of the gel and by re-connection of pre-treatment, residual oil volume and (2) high flow resistance in the channels during water flow is caused by significant saturations of oil remaining in the channels.

  20. Neutrophil Lymphocyte Ratio as a predictor of systemic inflammation - A cross-sectional study in a pre-admission setting.

    PubMed Central

    Venkatraghavan, Lashmi; Tan, Tze Ping; Mehta, Jigesh; Arekapudi, Anil; Govindarajulu, Arun; Siu, Eric

    2015-01-01

    Background: Neutrophil:lymphocyte ratio (NLR)  is an emerging biomarker that is used to predict postoperative mortality and morbidity in cardiac and cancer surgeries. The association of this biomarker with systemic illness and its usefulness in risk assessment of preoperative patients has not been fully elucidated. Objectives: To determine the prevalence of elevated NLR in preoperative patients and to examine the relationship between elevated NLR and the presence of systemic illnesses as well as anaesthesia risk indices such as American Society of Anesthesia (ASA) and the revised cardiac risk index (RCRI) scores.   Design: Cross-sectional study Setting: Anaesthesia pre-admission clinic, Toronto Western Hospital, Toronto, Canada Patients: We evaluated 1117 pre-operative patients seen at an anesthesia preadmission clinic. Results: NLR was elevated (>3.3) in 26.6% of target population. In multivariate analysis, congestive cardiac failure, diabetes mellitus and malignancy were independent risk factors predicting raised NLR. After regression analysis, a relationship between NLR and ASA score (Odds Ratio 1.78; 95% CI: 1.42-2.24) and revised cardiac risk index (RCRI, odds ratio 1.33; 95% CI: 1.09-1.64, p-value: 0.0063) was observed. Conclusions:  NLR was elevated (> 3.3) in 26.6% of patients. Congestive cardiac failure and malignancy were two constant predictors of elevated NLR at >3.3 and > 4.5. There was a strong association between NLR and anesthesia risk scoring tools of ASA and RCRI. PMID:26213612

  1. Study of 236U/238U ratio at CIRCE using a 16-strip silicon detector with a TOF system

    NASA Astrophysics Data System (ADS)

    De Cesare, M.; De Cesare, N.; D'Onofrio, A.; Gialanella, L.; Terrasi, F.

    2015-04-01

    Accelerator Mass Spectrometry (AMS) is presently the most sensitive technique for the measurement of long-lived actinides, e.g. 236U and xPu isotopes. A new actinide AMS system, based on a 3-MV pelletron tandem accelerator, is operated at the Center for Isotopic Research on Cultural and Environmental Heritage (CIRCE) in Caserta, Italy. In this paper we report on the procedure adopted to increase the 236U abundance sensitivity as low as possible. The energy and position determinations of the 236U ions, using a 16-strip silicon detector have been obtained. A 236U/238U isotopic ratio background level of about 2.9×10-11 was obtained, summing over all the strips, using a Time of Flight-Energy (TOF-E) system with a 16-strip silicon detector (4.9×10-12 just with one strip).

  2. A post-coding scheme for peak-to-average power ratio reduction in intensity modulated optical OFDM systems

    NASA Astrophysics Data System (ADS)

    Chen, Fang-ni; Wang, Zhong-peng

    2014-07-01

    An efficient post-coding strategy is proposed in this letter to reduce the peak-to-average power ratio (PAPR) of orthogonal frequency division multiplexing (OFDM) signals for optical intensity modulated direct detection (IM/DD) systems. The post-coding scheme based on discrete cosine transform (DCT) is employed after the inverse fast Fourier transform (IFFT) in the transmitter to reduce the PAPR of OFDM signals. This method is different from the conventional pre-coding scheme which is employed before IFFT operation. Numerical simulations demonstrate that the new DCT post-coding strategy can significantly reduce the PAPR than the conventional pre-coding scheme. Meantime, the bit error rate (BER) performance of the proposed post-coding system can be improved compared with the conventional pre-coding scheme.

  3. Analysis of linewidth and extinction ratio in directly modulated lasers for performance optimization in 10 Gbit/s CWDM systems

    NASA Astrophysics Data System (ADS)

    Campos, Carmina del Ro; Horche, Paloma R.; Martin-Minguez, Alfredo

    2010-08-01

    Direct Modulation Lasers (DMLs) have attracted increased attention during the past few years because of their intrinsic simplicity and cost-effectiveness, especially when applied to WDM metro and access networks. However, the output power waveform from a directly modulated laser is not an exact replica of the modulation current and its instantaneous optical frequency varies with time depending on the changes in optical power and the extinction ratio (ER) (an effect also known as frequency chirp). In this work, using an Optical Communication System Design Software, we have studied a directly modulated WDM 10 Gb/s system which transmission performance depends strongly on DML characteristics; simulation results have provided supplementary details about the effects of DML type (adiabatic or transient chirp dominated) as well as the effects of the optical output power. These details can provide useful design guidelines for constructing a WDM metro network.

  4. Predicting prey population dynamics from kill rate, predation rate and predator-prey ratios in three wolf-ungulate systems.

    PubMed

    Vucetich, John A; Hebblewhite, Mark; Smith, Douglas W; Peterson, Rolf O

    2011-11-01

    1.?Predation rate (PR) and kill rate are both fundamental statistics for understanding predation. However, relatively little is known about how these statistics relate to one another and how they relate to prey population dynamics. We assess these relationships across three systems where wolf-prey dynamics have been observed for 41 years (Isle Royale), 19 years (Banff) and 12 years (Yellowstone). 2.?To provide context for this empirical assessment, we developed theoretical predictions of the relationship between kill rate and PR under a broad range of predator-prey models including predator-dependent, ratio-dependent and Lotka-Volterra dynamics. 3.?The theoretical predictions indicate that kill rate can be related to PR in a variety of diverse ways (e.g. positive, negative, unrelated) that depend on the nature of predator-prey dynamics (e.g. structure of the functional response). These simulations also suggested that the ratio of predator-to-prey is a good predictor of prey growth rate. That result motivated us to assess the empirical relationship between the ratio and prey growth rate for each of the three study sites. 4.?The empirical relationships indicate that PR is not well predicted by kill rate, but is better predicted by the ratio of predator-to-prey. Kill rate is also a poor predictor of prey growth rate. However, PR and ratio of predator-to-prey each explained significant portions of variation in prey growth rate for two of the three study sites. 5.?Our analyses offer two general insights. First, Isle Royale, Banff and Yellowstone are similar insomuch as they all include wolves preying on large ungulates. However, they also differ in species diversity of predator and prey communities, exploitation by humans and the role of dispersal. Even with the benefit of our analysis, it remains difficult to judge whether to be more impressed by the similarities or differences. This difficulty nicely illustrates a fundamental property of ecological communities. Second, kill rate is the primary statistic for many traditional models of predation. However, our work suggests that kill rate and PR are similarly important for understanding why predation is such a complex process. PMID:21569029

  5. The Development of a Computerized System for the Estimation of Reliability for Measurement Systems Employing Interval or Ratio Data.

    ERIC Educational Resources Information Center

    Porter, D. Thomas

    Critical to precise quantitative research is reliability estimation. Researchers have limited tools, however, to assess the reliability of evolving instruments. Consequently, cursory assessment is typical and in-depth evaluation is rare. This paper presents a rationale for and description of PIAS, a computerized instrument analysis system. PIAS…

  6. Digit ratio 2D:4D in relation to autism spectrum disorders, empathizing, and systemizing: a quantitative review.

    PubMed

    Hönekopp, Johannes

    2012-08-01

    Prenatal testosterone (PT) effects have been proposed to increase systemizing (the drive to understand lawful input-output relationships), to decrease empathizing (the drive to understand others), and to cause autism via hypermasculinization of the brain. Digit ratio 2D:4D is a putative marker of PT effects in humans. An online study (n = 1896) into the relationship between the Reading the Mind in the Eyes Test (a widely used measure of empathizing) and self-measured 2D:4D in a nonclinical sample is reported. No evidence for a link between empathizing and 2D:4D in either females or males emerged. Further, three meta-analyses are presented that look into the relationships of 2D:4D with autism spectrum disorder (ASD), systemizing, and empathizing. 2D:4D was substantially lower (more masculine) in ASD-affected individuals than in normal controls (d = -0.58, P < 0.001). However, 2D:4D was found to be virtually unrelated to systemizing and empathizing in normal adults. The results support the idea that high PT is a risk factor for autism, but they challenge the view that PT substantially contributes to sex differences in systemizing and empathizing. Possibly, this pattern reflects an interaction effect, whereby PT drives ASD characteristic changes only in brains with a specific damage. PMID:22674640

  7. Plant lighting system with five wavelength-band light-emitting diodes providing photon flux density and mixing ratio control

    PubMed Central

    2012-01-01

    Background Plant growth and development depend on the availability of light. Lighting systems therefore play crucial roles in plant studies. Recent advancements of light-emitting diode (LED) technologies provide abundant opportunities to study various plant light responses. The LED merits include solidity, longevity, small element volume, radiant flux controllability, and monochromaticity. To apply these merits in plant light response studies, a lighting system must provide precisely controlled light spectra that are useful for inducing various plant responses. Results We have developed a plant lighting system that irradiated a 0.18 m2 area with a highly uniform distribution of photon flux density (PFD). The average photosynthetic PFD (PPFD) in the irradiated area was 438 micro-mol m2 s1 (coefficient of variation 9.6%), which is appropriate for growing leafy vegetables. The irradiated light includes violet, blue, orange-red, red, and far-red wavelength bands created by LEDs of five types. The PFD and mixing ratio of the five wavelength-band lights are controllable using a computer and drive circuits. The phototropic response of oat coleoptiles was investigated to evaluate plant sensitivity to the light control quality of the lighting system. Oat coleoptiles irradiated for 23 h with a uniformly distributed spectral PFD (SPFD) of 1 micro-mol m2 s1 nm1 at every peak wavelength (405, 460, 630, 660, and 735 nm) grew almost straight upwards. When they were irradiated with an SPFD gradient of blue light (460 nm peak wavelength), the coleoptiles showed a phototropic curvature in the direction of the greater SPFD of blue light. The greater SPFD gradient induced the greater curvature of coleoptiles. The relation between the phototropic curvature (deg) and the blue-light SPFD gradient (micro-mol m2 s1 nm1 m1) was 2 deg per 1 micro-mol m2 s1 nm1 m1. Conclusions The plant lighting system, with a computer with a graphical user interface program, can control the PFD and mixing ratios of five wavelength-band lights. A highly uniform PFD distribution was achieved, although an intentionally distorted PFD gradient was also created. Phototropic responses of oat coleoptiles to the blue light gradient demonstrated the merit of fine controllability of this plant lighting system. PMID:23173915

  8. HIGH FILL-OUT, EXTREME MASS RATIO OVERCONTACT BINARY SYSTEMS. X. THE NEWLY DISCOVERED BINARY XY LEONIS MINORIS

    SciTech Connect

    Qian, S.-B.; Liu, L.; Zhu, L.-Y.; He, J.-J.; Bernasconi, L. E-mail: yygcn@163.com

    2011-05-15

    The newly discovered short-period close binary star, XY LMi, has been monitored photometrically since 2006. Its light curves are typical EW-type light curves and show complete eclipses with durations of about 80 minutes. Photometric solutions were determined through an analysis of the complete B, V, R, and I light curves using the 2003 version of the Wilson-Devinney code. XY LMi is a high fill-out, extreme mass ratio overcontact binary system with a mass ratio of q = 0.148 and a fill-out factor of f = 74.1%, suggesting that it is in the late evolutionary stage of late-type tidal-locked binary stars. As observed in other overcontact binary stars, evidence for the presence of two dark spots on both components is given. Based on our 19 epochs of eclipse times, we found that the orbital period of the overcontact binary is decreasing continuously at a rate of dP/dt = -1.67 x 10{sup -7} days yr{sup -1}, which may be caused by mass transfer from the primary to the secondary and/or angular momentum loss via magnetic stellar wind. The decrease of the orbital period may result in the increase of the fill-out, and finally, it will evolve into a single rapid-rotation star when the fluid surface reaches the outer critical Roche lobe.

  9. Characterization Of High-Stroke High-Aspect Ratio Micro Electro Mechanical Systems Deformable Mirrors For Adaptive Optics

    NASA Astrophysics Data System (ADS)

    Bouchti, Mohamed Amine

    Adaptive optics MEMS deformable mirror, in conjunction with Shack Hartman wave front sensor and real-time controller, is capable of correcting time-varying aberrations in imaging applications through manipulating its mirror surface. Adaptive optics systems in astronomy for next generation large telescopes (30 meter primary mirrors) require a high stroke of 10microm of mechanical displacement. This required stroke would be achieved by MEMS deformable mirrors fabricated with high aspect ratio techniques. This thesis will review the designs of various types of high aspect actuators consisting of folded springs with rectangular and circular membranes as well as X-beam actuators. Finite element analysis (FEA) simulations of these designs have shown the ability of each design to achieve a stroke of approximately 9.4 microm. Also, FEA simulations proved that the X-beam actuators provide the best spring support while preventing tilting. In addition, this thesis will discuss device characterization and voltage vs. displacement test results for the high aspect ratio gold MEMS 16 x 16 X-beam actuators deformable mirror that has been bonded and packaged. The results have shown that the device is capable of achieving approximately 5.5 microm in individual actuator testing and 7microm in dual actuator testing.

  10. Disentangling community functional components in a litter-macrodetritivore model system reveals the predominance of the mass ratio hypothesis

    PubMed Central

    Bílá, Karolína; Moretti, Marco; Bello, Francesco; Dias, André TC; Pezzatti, Gianni B; Van Oosten, Arend Raoul; Berg, Matty P

    2014-01-01

    Recent investigations have shown that two components of community trait composition are important for key ecosystem processes: (i) the community-weighted mean trait value (CWM), related to the mass ratio hypothesis and dominant trait values in the community, and (ii) functional diversity (FD), related to the complementarity hypothesis and the divergence of trait values. However, no experiments controlling for the inherent dependence between CWM and FD have been conducted so far. We used a novel experimental framework to disentangle the unique and shared effects of CWM and FD in a leaf litter-macrodetritivore model system. We manipulated isopod assemblages varying in species number, CWM and FD of litter consumption rate to test the relative contribution of these community parameters in the decomposition process. We showed that CWM, but also the combination of CWM and FD, is a main factor controlling litter decomposition. When we tested individual biodiversity components separately, CWM of litter consumption rate showed a significant effect on decomposition, while FD and species richness alone did not. Our study demonstrated that (i) trait composition rather than species diversity drives litter decomposition, (ii) dominant trait values in the community (CWM) play a chief role in driving ecosystem processes, corroborating the mass ratio hypothesis, and (iii) trait dissimilarity can contribute in modulating the overall biodiversity effects. Future challenge is to assess whether the generality of our finding, that is, that dominant trait values (CWM) predominate over trait dissimilarity (FD), holds for other ecosystem processes, environmental conditions and different spatial and temporal scales. PMID:24634725

  11. Design of a high voltage input - output ratio dc-dc converter dedicated to small power fuel cell systems

    NASA Astrophysics Data System (ADS)

    Béthoux, O.; Cathelin, J.

    2010-12-01

    Consuming chemical energy, fuel cells produce simultaneously heat, water and useful electrical power [J.M. Andújar, F. Segura, Renew. Sust. Energy Rev. 13, 2309 (2009)], [J. Larminie, A. Dicks, Fuel Cell Systems Explained, 2nd edn. (John Wiley & Sons, 2003)]. As a matter of fact, the voltage generated by a fuel cell strongly depends on both the load power demand and the operating conditions. Besides, as a result of many design aspects, fuel cells are low voltage and high current electric generators. On the contrary, electric loads are commonly designed for small voltage swing and a high V/I ratio in order to minimize Joule losses. Therefore, electric loads supplied by fuel cells are typically fed by means of an intermediate power voltage regulator. The specifications of such a power converter are to be able to step up the input voltage with a high ratio (a ratio of 10 is a classic situation) and also to work with an excellent efficiency (in order to minimize its size, its weight and its losses) [A. Shahin, B. Huang, J.P. Martin, S. Pierfederici, B. Davat, Energy Conv. Manag. 51, 56 (2010)]. This paper deals with the design of this essential ancillary device. It intends to bring out the best structure for fulfilling this function. Several dc-dc converters with large voltage step-up ratios are introduced. A topology based on a coupled inductor or tapped inductor is closely studied. A detailed modelling is performed with the purpose of providing designing rules. This model is validated with both simulation and implementation. The experimental prototype is based on the following specifications: the fuel cell output voltage ranges from a 50 V open-voltage to a 25 V rated voltage while the load requires a constant 250 V voltage. The studied coupled inductor converter is compared with a classic boost converter commonly used in this voltage elevating application. Even though the voltage regulator faces severe FC specifications, the measured efficiency reaches 96% at the rated power whereas conventional boost efficiency barely achieves 91.5% in the same operating conditions.

  12. A heuristic approach to worst-case carrier-to-interference ratio maximization in satellite system synthesis

    NASA Technical Reports Server (NTRS)

    Reilly, Charles H.; Walton, Eric K.; Mata, Fernando; Mount-Campbell, Clark A.; Olen, Carl A.

    1990-01-01

    Consideration is given to the problem of allotting GEO locations to communication satellites so as to maximize the smallest aggregate carrier-to-interference (C/I) ratio calculated at any test point (assumed earth station). The location allotted to each satellite must be within the satellite's service arc, and angular separation constraints are enforced for each pair of satellites to control single-entry EMI. Solutions to this satellite system synthesis problem (SSSP) are found by embedding two heuristic procedures for the satellite location problem (SLP), in a binary search routine to find an estimate of the largest increment to the angular separation values that permits a feasible solution to SLP and SSSP. Numerical results for a 183-satellite, 208-beam example problem are presented.

  13. Systemic Inflammatory Response Based on Neutrophil-to-Lymphocyte Ratio as a Prognostic Marker in Bladder Cancer

    PubMed Central

    Kim, Hyung Suk; Ku, Ja Hyeon

    2016-01-01

    A growing body of evidence suggests that systemic inflammatory response (SIR) in the tumor microenvironment is closely related to poor oncologic outcomes in cancer patients. Over the past decade, several SIR-related hematological factors have been extensively investigated in an effort to risk-stratify cancer patients to improve treatment selection and to predict posttreatment survival outcomes in various types of cancers. In particular, one readily available marker of SIR is neutrophil-to-lymphocyte ratio (NLR), which can easily be measured on the basis of absolute neutrophils and absolute lymphocytes in a differential white blood cell count performed in the clinical setting. Many investigators have vigorously assessed NLR as a potential prognostic biomarker predicting pathological and survival outcomes in patients with urothelial carcinoma (UC) of the bladder. In this paper, we aim to present the prognostic role of NLR in patients with UC of the bladder through a thorough review of the literature. PMID:26880857

  14. Deep, Low Mass Ratio Overcontact Binary Systems. VI. AH Cancri in the Old Open Cluster M67

    NASA Astrophysics Data System (ADS)

    Qian, S.-B.; Liu, L.; Soonthornthum, B.; Zhu, L.-Y.; He, J.-J.

    2006-06-01

    CCD photometric light curves in the B and V bands obtained in 2001 and in the V band obtained in 2002 of AH Cnc in the old open cluster M67 are presented. It is shown that AH Cnc is a total-eclipsing binary and its light curves correspond to a typical A type according to Binnendijk's classification. The variations of the light curve around the primary minimum and second maximum were found. Our nine epochs of light minimum monitored from 2001 to 2005, including others collected from the literature, were used to create the first study of the period changes of the binary system. A cyclic oscillation with a period of 36.5 yr and an amplitude of 0.0237 days was discovered to be superposed on a continuous period increase (dP/dt=3.9910-7 days yr-1). Weak evidence indicates that there exists another small-amplitude period oscillation (A4=0.0035 days, P4=7.75 yr). The symmetric light curves in the B and V bands obtained in 2001 were analyzed with the 2003 version of the Wilson-Devinney code. It is confirmed that AH Cnc is a deep overcontact binary system with a high degree of overcontact f=58.5%+/-4.5% and a low mass ratio of q=0.1682+/-0.0012. The existence of the third light and the cyclic period oscillation both may suggest that AH Cnc is a triple system containing an unseen third body. The tertiary component may have played an important role in the origin of the overcontact binary star by removing angular momentum from the central system, which would cause it to have a short initial orbital period and thus evolve into an overcontact configuration by angular momentum loss. The long-term period increase can be interpreted as a mass transfer from the less massive component to the more massive one. As the orbital period increases, the decrease of the mass ratio will cause it finally to evolve into a single rapid-rotating star when the system meets the more familiar criterion that the orbital angular momentum be less than 3 times the total spin angular momentum. Therefore, AH Cnc may be a progenitor of the blue straggler stars in M67.

  15. Scaling of volume to surface ratio and doubling time in growing unicellular organisms: Do cells appear quantum-mechanical systems?

    SciTech Connect

    Atanasov, Atanas Todorov

    2014-10-06

    The scaling of physical and biological characteristics of the living organisms is a basic method for searching of new biophysical laws. In series of previous studies the author showed that in Poikilotherms, Mammals and Aves, the volume to surface ratio V×S{sup −1} (m) of organisms is proportional to their generation time T{sub gt}(s) via growth rate v (m s{sup −1}): V×S{sup −1} = v{sub gr}×T{sup r}. The power and the correlation coefficients are near to 1.0. Aim of this study is: i) to prove with experimental data the validity of the above equation for Unicellular organisms and ii) to show that perhaps, the cells are quantum-mechanical systems. The data for body mass M (kg), density ρ (kg/m{sup 3}), minimum and maximum doubling time T{sub dt} (s) for 50 unicellular organisms are assembled from scientific sources, and the computer program ‘Statistics’ is used for calculations. In result i) the analytical relationship from type: V×S{sup −1} = 4.46⋅10{sup −11}×T{sub dt} was found, where v{sub gr} = 4.46×10{sup −11} m/s and ii) it is shown that the products between cell mass M, cell length expressed by V/S ratio and growth rate v{sub gr} satisfied the Heisenberg uncertainty principle i.e. the inequalities V/S×M×v{sub gr}>h/2π and T{sub dt}×M×v{sub gr}{sup 2}>h/2π are valid, where h= 6.626×10{sup −34} J⋅s is the Planck constant. This rise the question: do cells appear quantum-mechanical systems?.

  16. Signal-to-noise ratio estimation in digital computer simulation of lowpass and bandpass systems with applications to analog and digital communications, volume 3

    NASA Technical Reports Server (NTRS)

    Tranter, W. H.; Turner, M. D.

    1977-01-01

    Techniques are developed to estimate power gain, delay, signal-to-noise ratio, and mean square error in digital computer simulations of lowpass and bandpass systems. The techniques are applied to analog and digital communications. The signal-to-noise ratio estimates are shown to be maximum likelihood estimates in additive white Gaussian noise. The methods are seen to be especially useful for digital communication systems where the mapping from the signal-to-noise ratio to the error probability can be obtained. Simulation results show the techniques developed to be accurate and quite versatile in evaluating the performance of many systems through digital computer simulation.

  17. Twofold peak-to-average power ratio reduction technique in direct-detection optical orthogonal frequency division multiplexing system

    NASA Astrophysics Data System (ADS)

    Guo, Lei; Li, Hui; Liu, Yejun; Gong, Xiaoxue; Zhou, Yufang

    2015-03-01

    High peak-to-average power ratio (PAPR) of the orthogonal frequency division multiplexing (OFDM) signal is one of the limitations to the transmission performance of an optical OFDM system. Many PAPR reduction techniques have been proposed in previous works. However, most of them only consider a single scheme while overlooking the complementary features of these techniques. We propose a twofold PAPR reduction technique called Hadamard transform combined with a partial transmit sequence (PTS) (HTCP). The proposed HTCP scheme combines the merits of two complementary techniques, i.e., Hadamard transform and PTS, to improve the performance of the optical OFDM system in terms of PAPR and bit error rate (BER). Furthermore, the side information generated in PTS is transmitted by pilot sequences which increase the utilization of subcarriers. Least square estimation is used to estimate the pilot signal's phase to recover the side information. The HTCP scheme is theoretically analyzed in a direct-detection optical OFDM system. Simulation results show that the HTCP scheme has a better performance with regards to PAPR and BER compared with the case of applying only the Hadamard transform or PTS technique.

  18. Spatial changes in carbon and nitrogen stable isotope ratios of sludge and associated organisms in a biological sewage treatment system.

    PubMed

    Onodera, Takashi; Kanaya, Gen; Syutsubo, Kazuaki; Miyaoka, Yuma; Hatamoto, Masashi; Yamaguchi, Takashi

    2015-01-01

    Carbon and nitrogen stable isotope ratios (?C and ??N) have been utilized as powerful tools for tracing energy or material flows within food webs in a range of environmental studies. However, the techniques have rarely been applied to the study of biological wastewater treatment technologies. We report on the spatial changes in ?C and ??N in sludge and its associated biotic community in a wastewater treatment system. This system consisted of an upflow anaerobic sludge blanket (UASB) and a down-flow hanging sponge (DHS) which is a novel type of trickling filter. The results showed clear spatial changes in the ?C and ??N of suspended solids (SS), retained sludge, and macrofauna (oligochaetes and fly larvae) in the system. The ?C and ??N was used as a natural tracer to determine the SS dynamic throughout the system. The results imply that SS in the DHS effluent was mainly eluted from the retained sludge in the lower section of the DHS reactor. The ??N of the retained sludge in the DHS reactor increased drastically from the inlet towards to the outlet, from -0.7 to 10.3. This phenomenon may be attributed to nitrogen conversion processes (i.e. nitrification and denitrification). The ??N of oligochaetes also increased from the inlet to the outlet, which corresponded well to that of the retained sludge. Thus, the ??N of the oligochaetes might simply mirror the ??N of the retained sludge. On the other hand, the ?C and ??N of sympatric fly larvae differed from those of the oligochaetes sampled, indicating dietary differences between the taxa. Therefore ?C and ??N reflected both treatment and dietary characteristics. We concluded that ?C and ??N values are potentially useful as alternative indicators for investigating microbial ecosystems and treatment characteristics of biological wastewater treatment systems. PMID:25462745

  19. Behavior of aircraft antiskid breaking systems on dry and wet runway surfaces: A slip-ratio-controlled system with ground speed reference from unbraked nose wheel

    NASA Technical Reports Server (NTRS)

    Tanner, J. A.; Stubbs, S. M.

    1977-01-01

    An experimental investigation was conducted at the Langley aircraft landing loads and traction facility to study the braking and cornering response of a slip ratio controlled aircraft antiskid braking system with ground speed reference derived from an unbraked nose wheel. The investigation, conducted on dry and wet runway surfaces, utilized one main gear wheel, brake, and tire assembly of a DC-9 series 10 airplane. During maximum braking, the average ratio of the drag force friction coefficient developed by the antiskid system to the maximum drag force friction coefficient available was higher on the dry surface than on damp and flooded surfaces, and was reduced with lighter vertical loads, higher yaw angles, and when new tire treads were replaced by worn treads. Similarly, the average ratio of side force friction coefficient developed by the tire under antiskid control to the maximum side force friction coefficient available to a freely rolling yawed tire decreased with increasing yaw angle, generally increased with ground speed, and decreased when tires with new treads were replaced by those with worn treads.

  20. Effects of doping concentration ratio on electrical characterization in pseudomorphic HEMT-based MMIC switches for ICT system

    NASA Astrophysics Data System (ADS)

    Mun, Jae-Kyoung; Oh, Jung-Hun; Sung, Ho-Kun; Wang, Cong

    2015-12-01

    The effects of the doping concentration ratios between upper and lower silicon planar-doping layers on the DC and RF characteristics of the double planar doped pseudomorphic high electron mobility transistors (pHEMTs) are investigated. From the device simulation, an increase of maximum extrinsic transconductance and a decrease of total on- and off-state capacitances are observed, as well as an increase of the upper to lower planar-doping concentration ratios (UTLPDR), which give rise to an enhancement of the switching speed and isolation characteristics. On the basis of simulation results, two types of pHEMTs are fabricated with two different UTLPDRs of 4:1 and 1:2. After applying these two types' pHEMTs, single-pole-double-throw (SPDT) transmitter/receiver monolithic microwave integrated circuit (MMIC) switches are also designed and fabricated. The SPDT MMIC switch with a 4:1 UTLPDR shows an insertion loss of 0.58 dB, isolation of 40.2 dB, and switching speed of 100 ns, respectively, which correspondingly indicate a 0.23 dB lower insertion loss, 2.90 dB higher isolation and 2.5 times faster switching speed than those of 1:2 UTLPDR at frequency range of 2-6 GHz. From the simulation results and comparative studies, we propose that the UTLPDR must be greater than 4:1 for the best switching performance. With the abovementioned excellent performances, the proposed switch would be quite promising in the application of information and communications technology system.

  1. Evaluating adaptation options of microcirculatory-tissue systems based on the physiological link of nutritive blood flow and redox ratio

    NASA Astrophysics Data System (ADS)

    Krupatkin, Alexander I.; Sidorov, Victor V.; Dremin, Victor V.; Dunaev, Andrey V.; Novikova, Irina N.; Zhu, Simian; Nabi, Ghulam; Litvinova, Karina S.; Baklanova, Anastasia P.; Bakshaliev, Ruslan M.; Ravcheev, Sergey A.

    2015-03-01

    Fluorescent spectroscopy (FS) is becoming more widely used in chemistry, biology, in various fields of medical technology and medicine in general. Many purulent wounds, burns and other destructive inflammatory processes are accompanied by changes in the fluorescent activity of the tissues, which occurs due to a misbalance in accumulation of natural fluorophores: FAD, NADH, lipofuscin, porphyrins, structural proteins, etc. The study of redox ratio (RR), characterizing the metabolic processes, is important in the assessment of the metabolic activity ofmicrocirculatory-tissue systems (MTS). However, one of the big problems of the FS method is still the correct interpretation of the data and the development of practical methods for its application in clinical medicine. To solve this problem and create new diagnostic criteria, we propose to evaluate the adaptive capacity of MTS using indicators of links between nutritive blood flow and redox ratio during a physiological rest and functional load (occlusion test). As is known, these parameters (RR and nutritive blood flow) characterize the metabolic activity of tissues.We have performedan experimental study of the relationship between the RR, defined by FS, and nutritive blood flow, defined by the methods of laser Doppler flowmetry. Preliminary results in the study of a complex approach to diagnosis of the state of biological tissue were obtained. A positive relationship between the nutritive blood flow in the microcirculatory channel and RR of skin tissue is observed.The speed of change of metabolism in the phase of occlusion and reperfusion and duration of phase of recovery may be the criteria for adaptive capabilities of MTS, which has practical significance for physiology and medicine.

  2. Impact of α-lactalbumin:β-lactoglobulin ratio on the heat stability of model infant milk formula protein systems.

    PubMed

    Crowley, Shane V; Dowling, Aisling P; Caldeo, Veronica; Kelly, Alan L; O'Mahony, James A

    2016-03-01

    Model infant milk formula systems (5.5% protein) were formulated to contain α-lactalbumin:β-lactoglobulin ratios of 0.1, 0.5, 1.3, 2.1 or 4.6 and assessed for heat stability and heat-induced changes. 'Humanising' the model formulas by increasing α-lactalbumin:β-lactoglobulin enhanced heat stability at 140°C in the pH range 6.6-6.9. The model formulas were analysed after lab-scale high-temperature short-time heating at pH 6.8. Gel electrophoresis indicated that increased heat stability in high α-lactalbumin:β-lactoglobulin samples was due to decreased covalent interactions between proteins. In low α-lactalbumin:β-lactoglobulin formulas, protein-protein interactions caused marked increases in protein particle size and viscosity of the heated systems; conversely, covalent interactions between proteins were minimal in high α-lactalbumin:β-lactoglobulin formulas. Reduced protein-protein interactions with increasing α-lactalbumin:β-lactoglobulin has important implications for subsequent processing; for example, lower viscosity post-heating may affect bulk density in spray-dried products or physical stability in ready-to-feed products. PMID:26471542

  3. An analytical system for stable isotope analysis on carbon monoxide using continuous-flow isotope-ratio mass spectrometry

    NASA Astrophysics Data System (ADS)

    Pathirana, S. L.; van der Veen, C.; Popa, M. E.; Röckmann, T.

    2015-12-01

    A fully automated system for the determination of δ13C and δ18O in atmospheric CO has been developed. CO is extracted from an air sample and converted into carbon dioxide (CO2) using the Schütze reagent. The isotopic composition is determined with an isotope-ratio mass spectrometer (IRMS) technique. The entire system is continuously flushed with high-purity helium (He), the carrier gas. The blank signal of the Schütze reagent is ~ 4 nmol mol-1, or 1-3 % of the typical sample size. The repeatability is 0.1 ‰ for δ13C and 0.2 ‰ for δ18O. The peak area allows for simultaneous determination of the mole fraction with an analytical repeatability of ~ 0.7 nmol mol-1 for 100 mL of ambient air (185.4 nmol mol-1 of CO). An automated single measurement is performed in only 18 min, and the achieved time efficiency (and small volume of sample air) allows for repetitive measurements practically.

  4. Influence of Cooling to Heating Load Ratio on Optimal Supply Water and Air Temperatures in an Air Conditioning System

    NASA Astrophysics Data System (ADS)

    Karino, Naoki; Shiba, Takashi; Yokoyama, Ryohei; Ito, Koichi

    In planning an air conditioning system, supply water and air temperatures are important factors from the viewpoint of energy saving and cost reduction. For example, lower temperature supply water and air for space cooling reduce the coefficient of performance of a refrigeration machine, and increase the thickness of heat insulation material. However, they enable larger temperature differences, and reduce equipment sizes and power demand. It is also an important subject to evaluate the effect of the supply water and air temperatures on energy saving and cost reduction on the annual basis by considering not only cooling but also heating loads. The purposes of this paper are to propose an optimal planning method for an air conditioning system with large temperature difference, and to analyze the effect of supply water and air temperatures on the long-term economics through a numerical study for an office building. As a result, it is shown that the proposed method effectively determines supply water and air temperatures, and the influence of the cooling to heating load ratio on the long-term economics is clarified.

  5. The alfalfa “almost darks” campaign: Pilot VLA HI observations of five high mass-to-light ratio systems

    SciTech Connect

    Cannon, John M.; Martinkus, Charlotte P.; Leisman, Lukas; Haynes, Martha P.; Giovanelli, Riccardo; Hallenbeck, Gregory; Jones, Michael E-mail: cmartink@macalester.edu E-mail: haynes@astro.cornell.edu E-mail: hallenbg@union.edu; and others

    2015-02-01

    We present new Very Large Array (VLA) H i spectral line imaging of five sources discovered by the ALFALFA extragalactic survey. These targets are drawn from a larger sample of systems that were not uniquely identified with optical counterparts during ALFALFA processing, and as such have unusually high H i mass to light ratios. The candidate “Almost Dark” objects fall into four broad categories: (1) objects with nearby H i neighbors that are likely of tidal origin; (2) objects that appear to be part of a system of multiple H i sources, but which may not be tidal in origin; (3) objects isolated from nearby ALFALFA H i detections, but located near a gas-poor early type galaxy; (4) apparently isolated sources, with no object of coincident redshift within ∼400 kpc. Roughly 75% of the 200 objects without identified counterparts in the α.40 database (Haynes et al. 2011) fall into category 1 (likely tidal), and were not considered for synthesis follow-up observations. The pilot sample presented here (AGC193953, AGC208602, AGC208399, AGC226178, and AGC233638) contains the first five sources observed as part of a larger effort to characterize H i sources with no readily identifiable optical counterpart at single dish resolution (3.′5). These objects span a range of H i mass [7.41 < log(M{sub Hi}) < 9.51] and H i mass to B-band luminosity ratios (3 < M{sub Hi}/L{sub B} < 9). We compare the H i total intensity and velocity fields to optical imaging drawn from the Sloan Digital Sky Survey and to ultraviolet imaging drawn from archival GALEX observations. Four of the sources with uncertain or no optical counterpart in the ALFALFA data are identified with low surface brightness optical counterparts in Sloan Digital Sky Survey imaging when compared with VLA H i intensity maps, and appear to be galaxies with clear signs of ordered rotation in the H i velocity fields. Three of these are detected in far-ultraviolet GALEX images, a likely indication of star formation within the last few hundred Myrs. One source (AGC208602) is likely tidal in nature, associated with the NGC 3370 group. Consistent with previous efforts, we find no “dark galaxies” in this limited sample. However, the present observations do reveal complex sources with suppressed star formation, highlighting both the observational difficulties and the necessity of synthesis follow-up observations to understand these extreme objects.

  6. The Alfalfa Almost Darks Campaign: Pilot VLA HI Observations of Five High Mass-To-Light Ratio Systems

    NASA Astrophysics Data System (ADS)

    Cannon, John M.; Martinkus, Charlotte P.; Leisman, Lukas; Haynes, Martha P.; Adams, Elizabeth A. K.; Giovanelli, Riccardo; Hallenbeck, Gregory; Janowiecki, Steven; Jones, Michael; Jzsa, Gyula I. G.; Koopmann, Rebecca A.; Nichols, Nathan; Papastergis, Emmanouil; Rhode, Katherine L.; Salzer, John J.; Troischt, Parker

    2015-02-01

    We present new Very Large Array (VLA) H i spectral line imaging of five sources discovered by the ALFALFA extragalactic survey. These targets are drawn from a larger sample of systems that were not uniquely identified with optical counterparts during ALFALFA processing, and as such have unusually high H i mass to light ratios. The candidate Almost Dark objects fall into four broad categories: (1) objects with nearby H i neighbors that are likely of tidal origin; (2) objects that appear to be part of a system of multiple H i sources, but which may not be tidal in origin; (3) objects isolated from nearby ALFALFA H i detections, but located near a gas-poor early type galaxy; (4) apparently isolated sources, with no object of coincident redshift within 400 kpc. Roughly 75% of the 200 objects without identified counterparts in the ?.40 database (Haynes et al. 2011) fall into category 1 (likely tidal), and were not considered for synthesis follow-up observations. The pilot sample presented here (AGC193953, AGC208602, AGC208399, AGC226178, and AGC233638) contains the first five sources observed as part of a larger effort to characterize H i sources with no readily identifiable optical counterpart at single dish resolution (3.?5). These objects span a range of H i mass [7.41 < log(MHi ) < 9.51] and H i mass to B-band luminosity ratios (3 < MHi /LB < 9). We compare the H i total intensity and velocity fields to optical imaging drawn from the Sloan Digital Sky Survey and to ultraviolet imaging drawn from archival GALEX observations. Four of the sources with uncertain or no optical counterpart in the ALFALFA data are identified with low surface brightness optical counterparts in Sloan Digital Sky Survey imaging when compared with VLA H i intensity maps, and appear to be galaxies with clear signs of ordered rotation in the H i velocity fields. Three of these are detected in far-ultraviolet GALEX images, a likely indication of star formation within the last few hundred Myrs. One source (AGC208602) is likely tidal in nature, associated with the NGC 3370 group. Consistent with previous efforts, we find no dark galaxies in this limited sample. However, the present observations do reveal complex sources with suppressed star formation, highlighting both the observational difficulties and the necessity of synthesis follow-up observations to understand these extreme objects.

  7. Assessment of Knee Cartilage Stress Distribution and Deformation Using Motion Capture System and Wearable Sensors for Force Ratio Detection

    PubMed Central

    Mijailovic, N.; Vulovic, R.; Milankovic, I.; Radakovic, R.; Filipovic, N.; Peulic, A.

    2015-01-01

    Knowledge about the knee cartilage deformation ratio as well as the knee cartilage stress distribution is of particular importance in clinical studies due to the fact that these represent some of the basic indicators of cartilage state and that they also provide information about joint cartilage wear so medical doctors can predict when it is necessary to perform surgery on a patient. In this research, we apply various kinds of sensors such as a system of infrared cameras and reflective markers, three-axis accelerometer, and force plate. The fluorescent marker and accelerometers are placed on the patient's hip, knee, and ankle, respectively. During a normal walk we are recording the space position of markers, acceleration, and ground reaction force by force plate. Measured data are included in the biomechanical model of the knee joint. Geometry for this model is defined from CT images. This model includes the impact of ground reaction forces, contact force between femur and tibia, patient body weight, ligaments, and muscle forces. The boundary conditions are created for the finite element method in order to noninvasively determine the cartilage stress distribution. PMID:26417382

  8. Supplementation with bypass fat in silvopastoral systems diminishes the ratio of milk saturated/unsaturated fatty acids.

    PubMed

    Mahecha, L; Angulo, J; Salazar, B; Cerón, M; Gallo, J; Molina, C H; Molina, E J; Suárez, J F; Lopera, J J; Olivera, M

    2008-04-01

    This study was conducted to evaluate if supplementing bypass fat to cows under silvopastoral systems, increases the concentration of unsaturated fatty acids in milk, thus improving the saturated/ unsaturated ratio without a negative effect on total milk yield in fat or protein. Two concentrations of two different sources of bypass fat were evaluated for 40 days, each in a group of 24 multiparous Lucerna (Colombian breed) cows. A cross-over design of 8 Latin squares 3 x 3 was used. The variables submitted to analysis were body condition, daily milk production and milk composition. Body condition, milk yield and milk quality were not different but there was a significant decrease in the amount of saturated fatty acid in both experiments while the unsaturated fat increased significantly in experiment 1 and remained stable in experiment 2. Results, such as these have as far as we know, not been reported previously and they provide an approach for the improvement of milk as a "functional food". PMID:18484123

  9. 40 CFR 141.534 - How does my system use this data to calculate an inactivation ratio?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... determine * * * (a) Uses only one point of disinfectant application (1) One inactivation ratio (CTcalc/CT99..., representing sequential inactivation ratios, between the point of disinfectant application and a point before... disinfectant application before the first customer The (CTcalc/CT99.9) value of each disinfection...

  10. 40 CFR 141.534 - How does my system use this data to calculate an inactivation ratio?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... determine * * * (a) Uses only one point of disinfectant application (1) One inactivation ratio (CTcalc/CT99..., representing sequential inactivation ratios, between the point of disinfectant application and a point before... disinfectant application before the first customer The (CTcalc/CT99.9) value of each disinfection...

  11. 40 CFR 141.534 - How does my system use this data to calculate an inactivation ratio?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... determine * * * (a) Uses only one point of disinfectant application (1) One inactivation ratio (CTcalc/CT99..., representing sequential inactivation ratios, between the point of disinfectant application and a point before... disinfectant application before the first customer The (CTcalc/CT99.9) value of each disinfection...

  12. 40 CFR 141.534 - How does my system use this data to calculate an inactivation ratio?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... determine * * * (a) Uses only one point of disinfectant application (1) One inactivation ratio (CTcalc/CT99..., representing sequential inactivation ratios, between the point of disinfectant application and a point before... disinfectant application before the first customer The (CTcalc/CT99.9) value of each disinfection...

  13. 40 CFR 141.534 - How does my system use this data to calculate an inactivation ratio?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... determine * * * (a) Uses only one point of disinfectant application (1) One inactivation ratio (CTcalc/CT99..., representing sequential inactivation ratios, between the point of disinfectant application and a point before... disinfectant application before the first customer The (CTcalc/CT99.9) value of each disinfection...

  14. Allometric scaling of indirect effects: body size ratios predict non-consumptive effects in multi-predator systems.

    PubMed

    Krenek, Lauren; Rudolf, Volker H W

    2014-11-01

    Non-consumptive effects (NCES) frequently lead to non-independent effects of multiple predators. While such emergent predator effects are ubiquitous in natural communities, the strength of these effects varies among studies and systems, making it difficult to predict a priory how changes in predator diversity influence prey suppression. Thus, identifying general scaling rules which can explain this variation of non-independent effects is vital for modelling natural communities and how they respond to biodiversity loss. Body size is a key trait determining the nature and strength of ecological interactions. While great progress has been made using allometric relationships to predict the interaction strength of predator-prey pairs, it is unknown whether similar relationships explain variation in the strength of NCEs, and how they are related to consumptive effects. Here, we experimentally manipulate the relative size difference of multiple predators to determine whether NCEs follow general allometric scaling relationships in an aquatic multi-predator system. Results demonstrate that the presence and strength of NCEs can vary dramatically across predator combinations. However, this variation scaled predictably with the size ratio of predators, increasing the size difference among predators increased NCEs. This pattern was driven by a size-mediated shift in 'food web motif' from competition to intraguild predation and a positive correlation of NCEs and intraguild predation rate. Results indicate that models which assume that consumers have independent effects are particularly likely to make erroneous predictions when predators differ substantially in size, but simple allometric relationships of NCEs could be used to correct this bias. PMID:24910170

  15. Nurse staff allocation by nurse patient ratio vs. a computerized nurse dependency management system: a comparative cost analysis of Australian and New Zealand hospitals.

    PubMed

    Heslop, Liza; Plummer, Virginia

    2012-01-01

    Coding, costing, and accounting for nursing care requirements in Australian public and private hospitals lacks systematic research. Nurse costing for two nurse staffing allocation methods--nurse patient ratios and a computerized nurse dependency management system--were compared. Retrospective nursing workload management data were obtained from hospital information systems in 21 acute care public and private hospitals in Australia and New Zealand. Descriptive statistics, cost analysis, and cost modeling were conducted for 103,269 shifts of nursing care. The comparison of costs for nursing staff by nurse-patient ratios and by a computerized nurse dependency management system demonstrated differences. The provision of nursing care using the computerized nurse dependency management system was, overall, lower in cost than for nurse-patient ratios. PMID:23346733

  16. DEEP, LOW-MASS RATIO OVERCONTACT BINARY SYSTEMS. XII. CK BOOTIS WITH POSSIBLE CYCLIC MAGNETIC ACTIVITY AND ADDITIONAL COMPANION

    SciTech Connect

    Yang, Y.-G.; Qian, S.-B.; Soonthornthum, B. E-mail: qsb@ynao.ac.cn

    2012-05-15

    We present precision CCD photometry, a period study, and a two-color simultaneous Wilson code solution of the short-period contact binary CK Bootis. The asymmetric light curves were modeled by a dark spot on the primary component. The result identifies that CK Boo is an A-type W UMa binary with a high fillout of f = 71.7({+-} 4.4)%. From the O - C curve, it is found that the orbital period changes in a complicated mode, i.e., a long-term increase with two sinusoidal variations. One cyclic oscillation with a period of 10.67({+-} 0.20) yr may result from magnetic activity cycles, which are identified by the variability of Max. I - Max. II. Another sinusoidal variation (i.e., A = 0.0131 days({+-} 0.0009 days) and P{sub 3} = 24.16({+-} 0.64) yr) may be attributed to the light-time effect due to a third body. This kind of additional companion can extract angular momentum from the central binary system. The orbital period secularly increases at a rate of dP/dt = +9.79 ({+-}0.80) Multiplication-Sign 10{sup -8} days yr{sup -1}, which may be interpreted by conservative mass transfer from the secondary to the primary. This kind of deep, low-mass ratio overcontact binaries may evolve into a rapid-rotating single star, only if the contact configuration do not break down at J{sub spin} > (1/3)J{sub orb}.

  17. Effect of combustion-chamber pressure and nozzle expansion ratio on theoretical performance of several rocket propellant systems

    NASA Technical Reports Server (NTRS)

    Morrell, Virginia E

    1956-01-01

    Theoretical calculations of specific impulse to determine the separate effects of increasing the combustion-chamber pressure and the nozzle expansion ratio on the performance of the propellants, hydrogen-fluorine, hydrogen-oxygen, ammonia-fluorine and AN-F-58 fuel - white fuming nitric acid (95 percent). The results indicate that an increase in specific impulse obtainable with an increase in combustion-chamber pressure is almost entirely caused by the increased expansion ratio through the nozzle.

  18. Examining the effect of length/width ratio on the hydro-dynamic behaviour in a DAF system using CFD and ADV techniques.

    PubMed

    Kwon, S B; Park, N S; Lee, S J; Ahn, H W; Wang, C K

    2006-01-01

    Dissolved air flotation (DAF) is a solid-liquid separation system that uses fine bubbles rising from the bottom to remove particles in water. In this study, we investigated the effect of L/W(L; length, W; width) on the hydrodynamic behavior in a DAF system using CFD (computational fluid dynamics) and ADV (acoustic Doppler velocimetry) technique. The factual full-scale DAF system, L/W ratio of 1:1, was selected and various UW ratio conditions (2:1, 3:1,4:1 and 5:1) were simulated with CFD. For modelling, 2-phase (gas-liquid) flow equations for the conservation of mass, momentum and turbulence quantities were solved using a Eulerian-Eulerian approach based on the assumption that a very small particle is applied in the DAF system. Also, for verification of CFD simulation results, we measured the actual velocity at some points in the full-scale DAF system with the ADV technique. Both the simulation and the measurement results were in good accordance with each other. We concluded that the L/W ratio and outlet geometry play an important role for flow pattern and fine bubble distribution in the flotation zone. In the ratio of 1:1, the dead zone is less than those in other cases. On the other hand, in the ratio of 5:1, the fine bubbles were more evenly distributed. PMID:16752775

  19. Evaluating the utility of B/Ca ratios in planktic foraminifera as a proxy for the carbonate system: A case study of Globigerinoides ruber

    NASA Astrophysics Data System (ADS)

    Henehan, Michael J.; Foster, Gavin L.; Rae, James W. B.; Prentice, Katy C.; Erez, Jonathan; Bostock, Helen C.; Marshall, Brittney J.; Wilson, Paul A.

    2015-04-01

    B/Ca ratios in foraminifera have attracted considerable scientific attention as a proxy for past ocean carbonate system. However, the carbonate system controls on B/Ca ratios are not straightforward, with Δ[CO32-] ([CO32-]in situ - [CO32-]at saturation) correlating best with B/Ca ratios in benthic foraminifera, rather than pH, B>(OH>)/4-HCO3-, or B>(OH>)/4-DIC (as a simple model of boron speciation in seawater and incorporation into CaCO3 would predict). Furthermore, culture experiments have shown that in planktic foraminifera properties such as salinity and [B]sw can have profound effects on B/Ca ratios beyond those predicted by simple partition coefficients. Here, we investigate the controls on B/Ca ratios in G. ruber via a combination of culture experiments and core-top measurements, and add to a growing body of evidence that suggests B/Ca ratios in symbiont-bearing foraminiferal carbonate are not a straightforward proxy for past seawater carbonate system conditions. We find that while B/Ca ratios in culture experiments covary with pH, in open ocean sediments this relationship is not seen. In fact, our B/Ca data correlate best with [PO43-] (a previously undocumented association) and in most regions, salinity. These findings might suggest a precipitation rate or crystallographic control on boron incorporation into foraminiferal calcite. Regardless, our results underscore the need for caution when attempting to interpret B/Ca records in terms of the ocean carbonate system, at the very least in the case of mixed-layer planktic foraminifera.

  20. Fuel Cycle System Analysis Implications of Sodium-Cooled Metal-Fueled Fast Reactor Transuranic Conversion Ratio

    SciTech Connect

    Steven J. Piet; Edward A. Hoffman; Samuel E. Bays; Gretchen E. Matthern; Jacob J. Jacobson; Ryan Clement; David W. Gerts

    2013-03-01

    If advanced fuel cycles are to include a large number of fast reactors (FRs), what should be the transuranic (TRU) conversion ratio (CR)? The nuclear energy era started with the assumption that they should be breeder reactors (CR > 1), but the full range of possible CRs eventually received attention. For example, during the recent U.S. Global Nuclear Energy Partnership program, the proposal was burner reactors (CR < 1). Yet, more recently, Massachusetts Institute of Technology's "Future of the Nuclear Fuel Cycle" proposed CR [approximately] 1. Meanwhile, the French company EDF remains focused on breeders. At least one of the reasons for the differences of approach is different fuel cycle objectives. To clarify matters, this paper analyzes the impact of TRU CR on many parameters relevant to fuel cycle systems and therefore spans a broad range of topic areas. The analyses are based on a FR physics parameter scan of TRU CR from 0 to [approximately]1.8 in a sodium-cooled metal-fueled FR (SMFR), in which the fuel from uranium-oxide-fueled light water reactors (LWRs) is recycled directly to FRs and FRs displace LWRs in the fleet. In this instance, the FRs are sodium cooled and metal fueled. Generally, it is assumed that all TRU elements are recycled, which maximizes uranium ore utilization for a given TRU CR and waste radiotoxicity reduction and is consistent with the assumption of used metal fuel separated by electrochemical means. In these analyses, the fuel burnup was constrained by imposing a neutron fluence limit to fuel cladding to the same constant value. This paper first presents static, time-independent measures of performance for the LWR [right arrow] FR fuel cycle, including mass, heat, gamma emission, radiotoxicity, and the two figures of merit for materials for weapon attractiveness developed by C. Bathke et al. No new fuel cycle will achieve a static equilibrium in the foreseeable future. Therefore, additional analyses are shown with dynamic, time-dependent measures of performance including uranium usage, TRU inventory, and radiotoxicity to evaluate the complex impacts of transition from the current uranium-fueled LWR system, and other more realistic impacts that may not be intuited from the time-independent steady-state conditions of the end-state fuel cycle. These analyses were performed using the Verifiable Fuel Cycle Simulation Model VISION. Compared with static calculations, dynamic results paint a different picture of option space and the urgency of starting a FR fleet. For example, in a static analysis, there is a sharp increase in uranium utilization as CR exceeds 1.0 (burner versus breeder). However, in dynamic analyses that examine uranium use over the next 1 to 2 centuries, behavior as CR crosses the 1.0 threshold is smooth, and other parameters such as the time required outside of reactors to recycle fuel become important. Overall, we find that there is no unambiguously superior value of TRU CR; preferences depend on the relative importance of different fuel cycle system objectives.

  1. Qualitative tissue differentiation by analysing the intensity ratios of atomic emission lines using laser induced breakdown spectroscopy (LIBS): prospects for a feedback mechanism for surgical laser systems.

    PubMed

    Kanawade, Rajesh; Mahari, Fanuel; Klämpfl, Florian; Rohde, Maximilian; Knipfer, Christian; Tangermann-Gerk, Katja; Adler, Werner; Schmidt, Michael; Stelzle, Florian

    2015-01-01

    The research work presented in this paper focuses on qualitative tissue differentiation by monitoring the intensity ratios of atomic emissions using 'Laser Induced Breakdown Spectroscopy' (LIBS) on the plasma plume created during laser tissue ablation. The background of this study is to establish a real time feedback control mechanism for clinical laser surgery systems during the laser ablation process. Ex-vivo domestic pig tissue samples (muscle, fat, nerve and skin) were used in this experiment. Atomic emission intensity ratios were analyzed to find a characteristic spectral line for each tissue. The results showed characteristic elemental emission intensity ratios for the respective tissues. The spectral lines and intensity ratios of these specific elements varied among the different tissue types. The main goal of this study is to qualitatively and precisely identify different tissue types for tissue specific laser surgery. PMID:24376030

  2. Importance of mixing ratio for a long-term CO2 flux measurement with a closed-path system

    NASA Astrophysics Data System (ADS)

    Nakai, Taro; Iwata, Hiroki; Harazono, Yoshinobu

    2011-07-01

    The new type closed-path CO2/H2O infrared gas analyser enables us to calculate CO2 fluxes from both the mixing ratio (?) and mass density of CO2 (?). After the WPL correction was applied, ? and ? were almost in accord with each other. However, ? tended to be slightly larger than ?, which resulted in a significant difference in cumulative CO2 fluxes. We found that this difference was explained by the pressure covariance term, which is normally omitted in the WPL correction. Therefore, ignoring the pressure covariance term in the WPL correction can cause a serious error in estimation of annual net ecosystem exchange. To reduce uncertainties in calculations, we recommend using the mixing ratio for calculation of CO2 fluxes when using the new type closed-path infrared gas analyser.

  3. Regulation of gonadal sex ratios and pubertal development by the thyroid endocrine system in zebrafish (Danio rerio)

    USGS Publications Warehouse

    Sharma, Prakash; Patino, Reynaldo

    2013-01-01

    We examined associations between thyroid condition, gonadal sex and pubertal development in zebrafish. Seventy-two-hour postfertilization larvae were reared in untreated medium or in the presence of goitrogens (sodium perchlorate, 0.82 mM; methimazole, 0.15 and 0.3 mM) or thyroxine (1 and 10 nM) for 30 days. Thyrocyte height, gonadal sex and gonadal development were histologically determined at 45 and 60 days postfertilization (dpf). Thyrocyte hypertrophy, an index of hypothyroidism, was observed at 45 and 60 dpf in perchlorate-treated but only at 45 dpf in methimazole-treated fish. Similarly, gonadal sex ratios were biased toward ovaries relative to control animals at 45 and 60 dpf in perchlorate-treated fish but only at 45 dpf in methimazole-treated fish. Gonadal sex ratios were biased toward testes at 45 and 60 dpf in thyroxine-treated fish. Spermatogenesis was delayed in testes from goitrogen-treated fish at 60 dpf relative to control values, but was unaffected in testes from thyroxine-treated individuals. Oogenesis seemed to be nonspecifically delayed in all treatments relative to control at 60 dpf. This study confirmed the previously reported association between hypothyroid condition and ovarian-skewed ratios, and hyperthyroid condition and testicular-skewed ratios, and also showed that male pubertal development is specifically delayed by experimental hypothyroidism. The simultaneous recovery from the hypothyroid and ovary-inducing effects of methimazole by 60 dpf (27 days post-treatment) suggests that the ovary-skewing effect of goitrogens is reversible when thyroid conditions return to basal levels before developmental commitment of gonadal sex. Conversely, the masculinizing effect of hyperthyroidism seems to be stable and perhaps permanent.

  4. High Aspect Ratio Wrinkles

    NASA Astrophysics Data System (ADS)

    Chen, Yu-Cheng; Crosby, Alfred

    2015-03-01

    Buckling-induced surface undulations are widely found in living creatures, for instance, gut villi and the surface of flower petal cells. These undulations provide unique functionalities with their extremely high aspect ratios. For the synthetic systems, sinusoidal wrinkles that are induced by buckling a thin film attached on a soft substrate have been proposed to many applications. However, the impact of the synthetic wrinkles have been restricted by limited aspect ratios, ranging from 0 to 0.35. Within this range, wrinkle aspect ratio is known to increase with increasing compressive strain until a critical strain is reached, at which point wrinkles transition to localizations, such as folds or period doublings. Inspired by the living creatures, we propose that wrinkles can be stabilized in high aspect ratio by manipulating the strain energy in the substrate. We experimentally demonstrate this idea by forming a secondary crosslinking network in the wrinkled surface and successfully achieve aspect ratio as large as 0.8. This work not only provides insights for the mechanism of high aspect ratio structures seen in living creatures, but also demonstrates significant promise for future wrinkle-based applications.

  5. High Aspect Ratio Wrinkles

    NASA Astrophysics Data System (ADS)

    Chen, Yu-Cheng; Crosby, Alfred J.

    2014-03-01

    Wrinkles occur when a compressive strain is imposed on a bilayer system composed of a stiff thin top film and a soft substrate. Wrinkle aspect ratio (wrinkle height divided by wavelength) is perhaps the most critical parameter for many promising wrinkle-based technologies; however, the current accessible range of aspect ratio has been restricted from 0 to 0.35. Within this range, wrinkle aspect ratio is known to increase with increasing compressive strain until a critical strain is reached, at which point wrinkles transition to localizations, such as folds or ridges. Here, we demonstrate the ability to delay this transition and ultimately expand the range of aspect ratios. Building upon recently developed models which link this transition to the asymmetric traction forces between the wrinkle crests and valleys for non-linear strain energy functions, we experimentally quantify the critical strain for both ridge and fold localizations as a function of the substrate material properties, initial stretch ratio, as well as film properties and geometry. Collectively, we demonstrate the ability to achieve wrinkle aspect ratios as large as 0.8, demonstrating significant promise for future wrinkle-based applications.

  6. Automated measurement of the bit-error rate as a function of signal-to-noise ratio for microwave communications systems

    NASA Technical Reports Server (NTRS)

    Kerczewski, Robert J.; Daugherty, Elaine S.; Kramarchuk, Ihor

    1987-01-01

    The performance of microwave systems and components for digital data transmission can be characterized by a plot of the bit-error rate as a function of the signal to noise ratio (or E sub b/E sub o). Methods for the efficient automated measurement of bit-error rates and signal-to-noise ratios, developed at NASA Lewis Research Center, are described. Noise measurement considerations and time requirements for measurement accuracy, as well as computer control and data processing methods, are discussed.

  7. Design options for achieving a rapidly variable heat-to-power ratio in a combined heat and power (CHP) fuel cell system (FCS)

    NASA Astrophysics Data System (ADS)

    Colella, Whitney

    This article calls for a change in paradigm within the fuel cells industry such that it focuses less on solely maximizing a fuel cell's electrical efficiency, and more on a fuel cell system's (FCS) overall combined thermal and electrical efficiency, as defined in relation to the instantaneous demand for heat and electricity. Based on market needs in the power generation sector, it emphasizes the need to develop FCSs such that they can achieve a heat-to-power ratio that can be rapidly varied. This article then delineates engineering methods to achieve a rapidly variable heat-to-power ratio for a combined heat and power (CHP) FCS.

  8. A multi-wavelength streak-optical-pyrometer for warm-dense matter experiments at NDCX-I and NDCX-II

    NASA Astrophysics Data System (ADS)

    Ni, P. A.; Bieniosek, F. M.; Henestroza, E.; Lidia, S. M.

    2014-01-01

    We report on a multi-wavelength streak-optical-pyrometer (SOP) developed the for warm-dense-matter (WDM) experiments at the existing NDCX-I facility and the NDCX-II facility currently being commissioned at LBNL. The SOP served as the primary temperature diagnostic in the recent NDCX-I experiments, in which an intense K+ beam was used to heat different metal samples into WDM states. The SOP consists of a spectral grating (visible and near-infrared spectral range) and a fast, high-dynamic-range optical streak camera. The instrument is calibrated absolutely with a NIST-traceable tungsten ribbon lamp and can itself be considered as an absolutely calibrated, time-resolving spectrometer. The sample temperature is determined from fitting the recorded thermal spectrum into the Planck formula multiplied by a model of emissivity.

  9. Measurements of concentrations of chlorofluoromethanes (CFMs) carbon dioxide and carbon isotope ratio in stratospheric and tropospheric air by grab-sampling systems

    NASA Technical Reports Server (NTRS)

    Itoh, T.; Kubo, H.; Honda, H.; Tominaga, T.; Makide, Y.; Yakohata, A.; Sakai, H.

    1985-01-01

    Measurements of concentrations of chlorofluoromethanes (CFMs), carbon dioxide and carbon isotope ratio in stratospheric and tropospheric air by grab-sampling systems are reported. The balloon-borne grab-sampling system has been launched from Sanriku Balloon Center three times since 1981. It consists of: (1) six sampling cylinders, (2) eight motor driven values, (3) control and monitor circuits, and (4) pressurized housing. Particular consideration is paid to the problem of contamination. Strict requirements are placed on the choice of materials and components, construction methods, cleaning techniques, vacuum integrity, and sampling procedures. An aluminum pressurized housing and a 4-m long inlet line are employed to prevent the sampling air from contamination by outgassing of sampling and control devices. The sampling is performed during the descent of the system. Vertical profiles of mixing ratios of CF2Cl2, CFCl3 and CH4 are given. Mixing ratios of CF2Cl2 and CFCl3 in the stratosphere do not show the discernible effect of the increase of those in the ground level background, and decrease with altitude. Decreasing rate of CFCl3 is larger than that of CF2Cl2. CH4 mixing ratio, on the other hand, shows diffusive equilibrium, as the photodissociation cross section of CH4 is small and concentrations of OH radical and 0(sup I D) are low.

  10. A dual-mode generalized likelihood ratio approach to self-reorganizing digital flight control system design

    NASA Technical Reports Server (NTRS)

    Bueno, R.; Chow, E.; Gershwin, S. B.; Willsky, A. S.

    1975-01-01

    The research is reported on the problems of failure detection and reliable system design for digital aircraft control systems. Failure modes, cross detection probability, wrong time detection, application of performance tools, and the GLR computer package are discussed.

  11. High on-off conductance switching ratio in optically-driven self-assembled conjugated molecular systems.

    PubMed

    Smaali, Kacem; Lenfant, Stphane; Karpe, Sandrine; Oafrain, Matna; Blanchard, Philippe; Deresmes, Dominique; Godey, Sylvie; Rochefort, Alain; Roncali, Jean; Vuillaume, Dominique

    2010-04-27

    A new azobenzene-thiophene molecular switch is designed, synthesized, and used to form self-assembled monolayers (SAM) on gold. An "on/off" conductance ratio up to 7 x 10(3) (with an average value of 1.5 x 10(3)) is reported. The "on" conductance state is clearly identified to the cis isomer of the azobenzene moiety. The high on/off ratio is explained in terms of photoinduced, configuration-related changes in the electrode-molecule interface energetics (changes in the energy position of the molecular orbitals with respect to the Fermi energy of electrodes) in addition to changes in the tunnel barrier length (length of the molecules). First principles density functional calculations demonstrate a better delocalization of the frontier orbitals as well as a stronger electronic coupling between the azobenzene moiety and the electrode for the cis configuration over the trans one. Measured photoionization cross sections for the molecules in the SAM are close to the known values for azobenzene derivatives in solution. PMID:20349942

  12. System and method to estimate compressional to shear velocity (VP/VS) ratio in a region remote from a borehole

    SciTech Connect

    Vu, Cung; Nihei, Kurt T; Schmitt, Denis P; Skelt, Christopher; Johnson, Paul A; Guyer, Robert; TenCate, James A; Le Bas, Pierre-Yves

    2012-10-16

    In some aspects of the disclosure, a method for creating three-dimensional images of non-linear properties and the compressional to shear velocity ratio in a region remote from a borehole using a conveyed logging tool is disclosed. In some aspects, the method includes arranging a first source in the borehole and generating a steered beam of elastic energy at a first frequency; arranging a second source in the borehole and generating a steerable beam of elastic energy at a second frequency, such that the steerable beam at the first frequency and the steerable beam at the second frequency intercept at a location away from the borehole; receiving at the borehole by a sensor a third elastic wave, created by a three wave mixing process, with a frequency equal to a difference between the first and second frequencies and a direction of propagation towards the borehole; determining a location of a three wave mixing region based on the arrangement of the first and second sources and on properties of the third wave signal; and creating three-dimensional images of the non-linear properties using data recorded by repeating the generating, receiving and determining at a plurality of azimuths, inclinations and longitudinal locations within the borehole. The method is additionally used to generate three dimensional images of the ratio of compressional to shear acoustic velocity of the same volume surrounding the borehole.

  13. [Process Optimization of Aerobic Granular Sludge Continuous-Flow System for the Treatment of Low COD/N Ratio Sewage].

    PubMed

    Lu, Lei; Xin, Xin; Lu, Hang; Zhu, Liao-dong; Xie, Si-jian; Wu, Yong

    2015-10-01

    The mature aerobic granular sludge (AGS) was inoculated in a continuous-flow joint constructor reactor to treat low chemical oxygen demand/nitrogen (COD/N) ratio sewage. The effects of aeration intensity and hydraulic retention time (HRT) on the denitrification and phosphorus removal efficiencies and the granular sludge stabilization were investigated. When the aeration intensity was 300 mL x min(-1) (superficial air upflow velocity of 1.2 cm x s(-1)) and the HRT was 7.5 h, the average removal efficiencies of COD, TN and TP were 76.34%, 51.23% and 53.70%, respectively. The mixed liquor suspended solids (MLSS) was only about 2 000 mg x L(-1), the sludge volume index ( SVI) was below 50 mL x g(-1), and the AGS exhibited complete forms and good settling performances. Additionally, the low COD/N ratios sewage could promote the production of extracellular polymeric substances (EPS) of AGS, and the PN proteins in EPS played a pivotal role in the maintenance of AGS stabilization. PMID:26841612

  14. Design verification and fabrication of active control systems for the DAST ARW-2 high aspect ratio wing, part 1

    NASA Technical Reports Server (NTRS)

    Mcgehee, C. R.

    1986-01-01

    A study was conducted under Drones for Aerodynamic and Structural Testing (DAST) program to accomplish the final design and hardware fabrication for four active control systems compatible with and ready for installation in the NASA Aeroelastic Research Wing No. 2 (ARW-2) and Firebee II drone flight test vehicle. The wing structure was designed so that Active Control Systems (ACS) are required in the normal flight envelope by integrating control system design with aerodynamics and structure technologies. The DAST ARW-2 configuration uses flutter suppression, relaxed static stability, and gust and maneuver load alleviation ACS systems, and an automatic flight control system. Performance goals and criteria were applied to individual systems and the systems collectively to assure that vehicle stability margins, flutter margins, flying qualities and load reductions are achieved.

  15. Design verification and fabrication of active control systems for the DAST ARW-2 high aspect ratio wing. Part 2: Appendices

    NASA Technical Reports Server (NTRS)

    Mcgehee, C. R.

    1986-01-01

    This is Part 2-Appendices of a study conducted under Drones for Aerodynamic and Structural Testing (DAST) Program to accomplish the final design and hardware fabrication for four active control systems compatible with and ready for installation in the NASA Aeroelastic Research Wing No. 2 (ARW-2) and Firebee II drone flight test vehicle. The wing structure was designed so that Active Control Systems (ACS) are required in the normal flight envelope by integrating control system design with aerodynamics and structure technologies. The DAST ARW-2 configuration uses flutter suppression, relaxed static stability, and gust and maneuver load alleviation ACS systems, and an automatic flight control system. Performance goals and criteria were applied to individual systems and the systems collectively to assure that vehicle stability margins, flutter margins, flying qualities, and load reductions were achieved.

  16. Alkali injection system with controlled CO.sub.2 /O.sub.2 ratios for combustion of coal

    DOEpatents

    Berry, Gregory F. (Naperville, IL)

    1988-01-01

    A high temperature combustion process for an organic fuel containing sulfur n which the nitrogen of air is replaced by carbon dioxide for combination with oxygen with the ratio of CO.sub.2 /O.sub.2 being controlled to generate combustion temperatures above 2000 K. for a gas-gas reaction with SO.sub.2 and an alkali metal compound to produce a sulfate and in which a portion of the carbon-dioxide rich gas is recycled for mixing with oxygen and/or for injection as a cooling gas upstream from heating exchangers to limit fouling of the exchangers, with the remaining carbon-dioxide rich gas being available as a source of CO.sub.2 for oil recovery and other purposes.

  17. The effect of partial coherence in receiving system noise temperature on array gain for telemetry and radio frequency carrier reception for receiving systems with unequal predetection signal-to-noise ratios

    NASA Technical Reports Server (NTRS)

    Brockman, M. H.

    1983-01-01

    Signal to noise ratio improvement realized by arraying receiving systems or stations for coherent reception is reduced when some portion of the predetection noise is coherent in the array. This effect for arrayed receiving systems with unequal apertures including expected performance for selected planets of the solar system within the array beamwidth is examined.

  18. Tests of variable-band multilayers designed for investigating optimal signal-to-noise vs artifact signal ratios in Dual-Energy Digital Subtraction Angiography (DDSA) imaging systems

    SciTech Connect

    Boyers, D.; Ho, A.; Li, Q.; Piestrup, M.; Rice, M.; Tatchyn, R.

    1993-08-01

    In recent work, various design techniques were applied to investigate the feasibility of controlling the bandwidth and bandshape profiles of tungsten/boron-carbon (W/B{sub 4}C) and tungsten/silicon (W/Si) multilayers for optimizing their performance in synchrotron radiation based angiographical imaging systems at 33 keV. Varied parameters included alternative spacing geometries, material thickness ratios, and numbers of layer pairs. Planar optics with nominal design reflectivities of 30%--94% and bandwidths ranging from 0.6%--10% were designed at the Stanford Radiation Laboratory, fabricated by the Ovonic Synthetic Materials Company, and characterized on Beam Line 4-3 at the Stanford Synchrotron Radiation Laboratory, in this paper we report selected results of these tests and review the possible use of the multilayers for determining optimal signal to noise vs. artifact signal ratios in practical Dual-Energy Digital Subtraction Angiography systems.

  19. Direct emissions of N2O, CO 2, and CH 4 from A/A/O bioreactor systems: impact of influent C/N ratio.

    PubMed

    Ren, Yangang; Wang, Jinhe; Xu, Li; Liu, Cui; Zong, Ruiqiang; Yu, Jianlin; Liang, Shuang

    2015-06-01

    Direct emissions of N2O, CO2, and CH4, three important greenhouse gases (GHGs), from biological sewage treatment process have attracted increasing attention worldwide, due to the increasing concern about climate change. Despite the tremendous efforts devoted to understanding GHG emission from biological sewage treatment process, the impact of influent C/N ratios, in terms of chemical oxygen demand (COD)/total nitrogen (TN), on an anaerobic/anoxic/oxic (A/A/O) bioreactor system has not been investigated. In this work, the direct GHG emission from A/A/O bioreactor systems fed with actual sewage was analyzed under different influent C/N ratios over a 6-month period. The results showed that the variation in influent carbon (160 to 500mg/L) and nitrogen load (35 to 95mg/L) dramatically influenced pollutant removal efficiency and GHG production from this process. In the A/A/O bioreactor systems, the GHG production increased from 26-39 to 112-173g CO2-equivalent as influent C/N ratios decreased from 10.3/10.7 to 3.5/3.8. Taking consideration of pollutant removal efficiency and direct biogenic GHG (N2O, CO2, and CH4) production, the optimum influent C/N ratio was determined to be 7.1/7.5, at which a relatively high pollutant removal efficiency and meanwhile a low level of GHG production (30.4g CO2-equivalent) can be achieved. Besides, mechanical aeration turned out to be the most significant factor influencing GHG emission from the A/A/O bioreactor systems. PMID:25850740

  20. High Resolution Imaging of the Anomalous Flux-Ratio Gravitational Lens System CLASS B2045+265: Dark Or Luminous Satellites?

    SciTech Connect

    McKean, J.P.; Koopmans, L.V.E.; Flack, C.E.; Fassnacht, C.D.; Thompson, D.; Matthews, K.; Blandford, R.D.; Readhead, A.C.S.; Soifer, B.T.; /UC, Davis /Bonn, Max Planck Inst., Radioastron. /Kapteyn Astron. Inst., Groningen /Bemidji State U. /Caltech /KIPAC, Menlo Park /Cornell U., Astron. Dept.

    2006-11-10

    The existence of flux-ratio anomalies between fold and cusp images in galaxy-scale strong-lens systems has led to an interpretation based on the presence of a high mass-fraction of cold-dark-matter (CDM) substructures around galaxies, as predicted by numerical N-body simulations. These substructures can cause large perturbations of the image magnifications, leading to changes in the image flux ratios. The flux-ratio anomaly is particularly evident in the radio-loud quadruple gravitational lens system CLASS B2045+265. In this paper, new high-resolution radio, optical, and infrared imaging of B2045+265 is presented which sheds more light on this anomaly and its possible causes. First, deep Very Long Baseline Array observations show very compact images, possibly with a hint of a jet, but with no evidence for differential scattering or scatter broadening. Hence, the flux-ratio anomaly is unlikely to be caused by refractive scattering in either the Milky Way or the lens galaxy. Second, optical and infrared observations with the Hubble Space Telescope and through Adaptive-Optics imaging with the W. M. Keck Telescope, show a previously undiscovered object--interpreted as a (tidally disrupted) dwarf satellite based on its colors and slight extension--between the main lens galaxy and the three anomalous flux-ratio images. Third, color variations in the early-type lens galaxy indicate recent star-formation, possibly the result of secondary infall of gas-rich satellites. A population of young galaxies around the lens system could explain the previously discovered strong [O II] emission. However, spiral structure and/or normal star formation in the lens galaxy cannot be excluded. In light of these new data, we propose a lens model for the system, including the observed dwarf satellite, which reproduces all positional and flux-ratio constraints, without the need for additional CDM substructure. Although the model is peculiar in that the dwarf galaxy must be highly flattened, the model is very similar to recently proposed mass models based on high-order multipole expansions.

  1. Evolutionary outcomes for pairs of planets undergoing orbital migration and circularization: second-order resonances and observed period ratios in Kepler's planetary systems

    NASA Astrophysics Data System (ADS)

    Xiang-Gruess, M.; Papaloizou, J. C. B.

    2015-05-01

    In order to study the origin of the architectures of low-mass planetary systems, we perform numerical surveys of the evolution of pairs of coplanar planets in the mass range (1-4) M?. These evolve for up to 2 107 yr under a range of orbital migration torques and circularization rates assumed to arise through interaction with a protoplanetary disc. Near the inner disc boundary, significant variations of viscosity, interaction with density waves or with the stellar magnetic field could occur and halt migration, but allow circularization to continue. This was modelled by modifying the migration and circularization rates. Runs terminated without an extended period of circularization in the absence of migration torques gave rise to either a collision, or a system close to a resonance. These were mostly first order with a few per cent terminating in second-order resonances. Both planetary eccentricities were small <0.1 and all resonant angles liberated. This type of survey produced only a limited range of period ratios and cannot reproduce Kepler observations. When circularization alone operates in the final stages, divergent migration occurs causing period ratios to increase. Depending on its strength the whole period ratio range between 1 and 2 can be obtained. A few systems close to second-order commensurabilities also occur. In contrast to when arising through convergent migration, resonant trapping does not occur and resonant angles circulate. Thus, the behaviour of the resonant angles may indicate the form of migration that led to near resonance.

  2. Characterizing the zone of influence of dark matter clumps on image positions and flux ratios in gravitational lensing systems

    NASA Astrophysics Data System (ADS)

    Johnson, Jyothisraj; Keeton, Charles R.; Brennan, Sean

    2016-01-01

    The Cold Dark Matter (CDM) model of the universe predicts that there should be hundreds to thousands of clumps surrounding a massive galaxy. However, observations have shown that we only see dozens of dwarf galaxies and not the hundreds to thousands that are predicted. This means that either the CDM model prediction is wrong, or most of the substructure consists of dark matter that cannot be observed directly. Massive galaxies serve as natural gravitational lenses throughout the universe that allow us to indirectly observe these dark matter perturbations. Strong gravitational lensing occurs when these massive elliptical galaxies have the critical density required to bend light from a source located behind it and produce multiple images of that same source. Dark matter clumps located near these multiple images affect their positions and flux ratios. We used lensing simulations to quantify how dark matter clumps affect image properties and to characterize this zone of influence through color maps of chi-squared values. Our results showed regions around each of the image positions that display significant perturbations for low mass clumps. For higher mass clumps, however, these distinct regions bleed together. We found that there is a correlation between the mass of the dark matter clump and the area it perturbs.This research has been supported by NSF grant PHY-1263280.

  3. ARGALI: an automatic cup-to-disc ratio measurement system for glaucoma detection and AnaLysIs framework

    NASA Astrophysics Data System (ADS)

    Liu, J.; Wong, D. W. K.; Lim, J. H.; Li, H.; Tan, N. M.; Wong, T. Y.

    2009-02-01

    Glaucoma is an irreversible ocular disease leading to permanent blindness. However, early detection can be effective in slowing or halting the progression of the disease. Physiologically, glaucoma progression is quantified by increased excavation of the optic cup. This progression can be quantified in retinal fundus images via the optic cup to disc ratio (CDR), since in increased glaucomatous neuropathy, the relative size of the optic cup to the optic disc is increased. The ARGALI framework constitutes of various segmentation approaches employing level set, color intensity thresholds and ellipse fitting for the extraction of the optic cup and disc from retinal images as preliminary steps. Following this, different combinations of the obtained results are then utilized to calculate the corresponding CDR values. The individual results are subsequently fused using a neural network. The learning function of the neural network is trained with a set of 100 retinal images For testing, a separate set 40 images is then used to compare the obtained CDR against a clinically graded CDR, and it is shown that the neural network-based result performs better than the individual components, with 96% of the results within intra-observer variability. The results indicate good promise for the further development of ARGALI as a tool for the early detection of glaucoma.

  4. Asymmetric thymocyte death underlies the CD4:CD8 T-cell ratio in the adaptive immune system

    PubMed Central

    Sinclair, Charles; Bains, Iren; Yates, Andrew J.; Seddon, Benedict

    2013-01-01

    It has long been recognized that the T-cell compartment has more CD4 helper than CD8 cytotoxic T cells, and this is most evident looking at T-cell development in the thymus. However, it remains unknown how thymocyte development so favors CD4 lineage development. To identify the basis of this asymmetry, we analyzed development of synchronized cohorts of thymocytes in vivo and estimated rates of thymocyte death and differentiation throughout development, inferring lineage-specific efficiencies of selection. Our analysis suggested that roughly equal numbers of cells of each lineage enter selection and found that, overall, a remarkable ∼75% of cells that start selection fail to complete the process. Importantly it revealed that class I-restricted thymocytes are specifically susceptible to apoptosis at the earliest stage of selection. The importance of differential apoptosis was confirmed by placing thymocytes under apoptotic stress, resulting in preferential death of class I-restricted thymocytes. Thus, asymmetric death during selection is the key determinant of the CD4:CD8 ratio in which T cells are generated by thymopoiesis. PMID:23858460

  5. Dynamic Response and Signal to Noise Ratio Investigation of NIR-FBG Dynamic Sensing System for Monitoring Thin- walled Composite Plate

    NASA Astrophysics Data System (ADS)

    Hafizi, Z. M.; Epaarachchi, J.

    2015-12-01

    Optical fiber systems for dynamic response measurement become an attractive study nowadays especially in the field of Structural Health Monitoring (SHM). This work presents the investigation of an optical fiber sensor system utilizing Near Infra-Red Fiber Bragg Grating (NIR-FBG) sensor for SHM of a thin-walled composite structure. In this study, a comparison between the experimental result and simulation study using finite element analysis has been presented. By comparing both results, the FBG dynamic sensing system was shown to have an excellent capability in acquiring dynamic response due to flexural wave propagations. In the meantime, a signal to noise ratio (SNR) study was also performed to several FBG dynamic sensor systems; particularly to see the comparison between NIR-FBG sensor and 1550 nm FBG sensor. Furthermore, with a proper configuration, an NIR-FBG system was proved to have better performance than the 1550 nm based FBG sensor.

  6. A simple peak-to-average power ratio reduction scheme for all optical orthogonal frequency division multiplexing systems with intensity modulation and direct detection.

    PubMed

    Liang, Xiaojun; Li, Wei; Ma, Weidong; Wang, Kai

    2009-08-31

    This paper fundamentally investigates the peak-to-average power ratio (PAPR) theory in all optical orthogonal frequency division multiplexing (OFDM) systems which employ intensity modulation-direct detection (IM-DD) scheme. We propose a low-complexity PAPR reduction scheme based on phase pre-emphasis. Simulations show that the proposed scheme brings about a 3.74 dB PAPR reduction and better nonlinear impairment tolerance in a 16x10Gb/s IM-DD all optical OFDM system. PMID:19724560

  7. New nonlinear companding technique to decrease peak to average power ratio of the optical orthogonal frequency division multiplexing system based on Hartley transform

    NASA Astrophysics Data System (ADS)

    Jiang, Shan; Deng, Honggui; Xiao, Wei; Du, Jie

    2015-10-01

    The problem of optics orthogonal frequency division multiplexing (optical-OFDM) communication lies in the peak to average power ratio (PAPR), which seriously affects the quality of communication systems. A composite technique, which combines the Hartley transform and KC companding technique to reduce the PAPR of an optical-OFDM system, is proposed. The proposed technique can obtain the same quality of OFDM signals and offer an improved bit error rate performance by using Hartley transform instead of the traditional Fourier transform, while the computational complexity is almost halved. Theoretical analysis and simulation results show that the proposed technique has a superior performance for reducing the PAPR when compared to the traditional technique.

  8. Impact of the New Jersey all-payer rate-setting system: an analysis of financial ratios.

    PubMed

    Rosko, M D

    1989-01-01

    Although prospective payment may contain costs, many analysts are concerned about the unintended consequences of rate regulation. This article presents the results of a case-study analysis of the New Jersey rate-setting programs during the period 1977-1985. Using measures of profitability, liquidity, and leverage, data for New Jersey, the Northeast, and the United States as a whole are used to contrast the impact of two forms of prospective payment. After attempting alternative cost-containment methods, the New Jersey Department of Health implemented an all-payer system in which prospective rates of compensation were established for DRGs. The new rate-setting system was designed to control costs, improve access to care, maintain quality of services, ensure financial viability of efficient providers, and limit the payment differentials associated with cost shifting. The results of this study have a number of implications for the evaluation of all-payer rate regulation. First, although the New Jersey all-payer system was more successful than the partial-payer program in restraining the rate of increase in cost per case, savings were achieved without adversely affecting the viability of regulated hospitals. Second, the large differentials among payers that were associated with the partial-payer program were reduced dramatically by the all-payer program. Third, using the financial position of inner-city hospitals relative to suburban hospitals as a measure of equity, the all-payer system appeared to be a fairer method of regulating rates. PMID:10291809

  9. "Perfect Zoom System" which enables both a zoom ratio of 25:1 and a high-resolution in stereo microscope

    NASA Astrophysics Data System (ADS)

    Miyake, Norio; Mizuta, Masahiro; Shinada, Nobuhiro; Nakayama, Hiroaki; Ohuchi, Yumiko

    2015-09-01

    A stereomicroscope can stereoscopically observe an object with protrusions and recesses as if the object were viewed by both eyes. Such stereomicroscopes use an optical system to create two slightly different viewing angles of an object. The different images are both enlarged and viewed through two eyepieces. Each of the observation optical systems includes a variable magnification mechanism which is called a zoom lens system. In recent years, a demand for stereomicroscopes that can observe a wide variable magnification range has been increasing along with the diversification of applications. However, there are no stereomicroscope zoom lenses with both a high resolution and a large zoom ratio. We developed the "Perfect Zoom System" which can reduce the light flux diameter going through the objective lens in the low-power state. In the "Perfect Zoom System", the zoom lens groups move along not only the optical axes but also perpendicular to the axes. Therefore, the objective lens could be made smaller by decentering the G2 and G3 group lenses in zoom lens group. We achieved a high resolution and a zoom ratio of 25:1.

  10. Hydrogen isotope abundances in the solar system. Part II: Meteorites with terrestrial-like D / H ratio

    NASA Astrophysics Data System (ADS)

    Robert, Franois; Javoy, Marc; Halbout, Jrme; Dimon, Bernard; Merlivat, Liliane

    1987-07-01

    Hydrogen isotopic compositions were determined by progressive pyrolysis in type 6 to type 3 ordinary chondrites. A marked decrease in the isotopic composition patterns was observed at intermediate temperatures (250-300C) and results from the pyrolysis of a D-depleted component. A ?D value of-400 for this component can be inferred from a mathematical treatment of the H concentration release pattern. At higher temperatures (600 to 900C) the bimodal ?D pattern was observed in Hedjaz (L3-L6) with negative ?D values, suggesting the presence of a carbonaceous chondrite-like organic polymer in this meteorite. A peak in the ?D pattern was observed at high temperature in all the analyzed samples, suggesting that D-rich H is widespread among meteorites. A minimum of 50% of the total H is concentrated in the fine-grained particles (the "holy smoke") of equilibrated chondrites, reinforcing the idea that H is associated with the C. An internal correlation between the bulk isotopic composition of HT H 2 and the maximum measured D/H ratio is interpreted as the result of either the mixing of two components (Model 1), namely a D-depleted H at -400 and a D-rich H at +5000, or a progressive isotopic fractionation of a D-depleted reservoir (Model 2). The first model (the favored one) implies that the two components were present in different proportions at the time of the formation of each meteorite, and that metamorphism has homogeneized the two phases. The uniqueness of the two isotopic end-members for all meteorites is not demonstrated. The second model relates the isotopic fractionation of the D-rich phase to the degree of equilibration of chondrites. All the isotopic variations reported in this work for ordinary chondrites can be explained quantitatively by either one of these two models. The upper and lower limits for the D/Hratios of the D-rich and of the D-depleted H in meteorites are calculated to be 1.1 10 -3 and 9 10 -5, respectively.

  11. Engineered high aspect ratio vertical nanotubes as a model system for the investigation of catalytic methanol synthesis over Cu/ZnO.

    PubMed

    Gder, Firat; Frei, Elias; Kckbayrak, Umut M; Menzel, Andreas; Thomann, Ralf; Luptak, Roman; Hollaender, Bernd; Krossing, Ingo; Zacharias, Margit

    2014-02-12

    Catalytically synthesized methanol from H2 and CO2 using porous Cu/ZnO aggregates is a promising, carbon neutral, and renewable alternative to replace fossil fuel based transport fuels. However, the absence of surface-engineered model systems to understand and improve the industrial Cu/ZnO catalyst poses a big technological gap in efforts to increase industrial methanol conversion efficiency. In this work, we report a novel process for the fabrication of patterned, vertically aligned high aspect ratio 1D nanostructures on Si that can be used as an engineered model catalyst. The proposed strategy employs near-field phase shift lithography (NF-PSL), deep reactive ion etching (DRIE), and atomic layer deposition (ALD) to pattern, etch, and coat Si wafers to produce high aspect ratio 1D nanostructures. Using this method, we produced a model system consisting of high aspect ratio Cu-decorated ZnO nanotubes (NTs) to investigate the morphological effects of ZnO catalyst support in comparison to the planar Cu/ZnO catalyst in terms of the catalytic reactions. The engineered catalysts performed 70 times better in activating CO2 than the industrial catalyst. In light of the obtained results, several important points are highlighted, and recommendations are made to achieve higher catalytic performance. PMID:24392784

  12. Effects of different influent C/N ratios on the performance of various earthworm eco-filter systems: nutrient removal and greenhouse gas emission.

    PubMed

    Huang, Wei; Zhao, Yongjun; Wu, Jiangtao; Zhang, Jibiao; Zheng, Zheng

    2014-01-01

    In this study, we sought to identify influent carbon-to-nitrogen (C/N) ratios that yield relatively high nutrient removal efficiency with relatively low greenhouse gas (GHG) emissions. The earthworm eco-filter (EE) system, which is composed of earthworms and plants (EP group), was found to be optimal for maximizing nutrient removal while reducing GHG emissions. In this EE system, the optimal influent C/N ratio for nutrient removal and GHG emission under C2N treatment conditions. Nutrient removal efficiency under this condition was 85.19 6.40% chemical oxygen demand, 71.99 11.28% total nitrogen, and 77.91 8.51% total phosphorus, while the CO2 emission rate was 678.89 201.87 mg m(-2) h(-1). Moreover, the highest nutrient removal and GHG emission rates were both achieved in late summer (August). Thus, carbon variation, season, system variation, as well as synergistic interaction between system variations and seasons, significantly affect nutrient removal efficiencies and GHG emissions. PMID:23861043

  13. Evaluation of a tracer release and measurement system for the detection and quantification of air emissions using the tracer ratio method

    NASA Astrophysics Data System (ADS)

    Hecobian, A.; Clements, A. L.; Shonkwiler, K. B.; Williams, C. M.; Wells, B. L.; MacDonald, L. P.; Pierce, J. R.; Ham, J. M.; Collett, J. L.

    2013-12-01

    The number of oil and gas production operations is increasing as is their proximity to residential areas. These facilities have been known to emit methane and other volatile organic compounds (VOCs) to the atmosphere during the different phases of development and operation. To gain a better understanding of the types and magnitude of these emissions, accurate methods for identifying and measuring the plumes released from these sources are needed. One of the most common methods for characterization of emissions is the tracer ratio. In this method, a known amount of a tracer gas is released near the potential emission source, both the tracer and the compound(s) of interest are then measured at a location downwind of the potential emissions; and the emission rate is estimated based on the ratio of the compound of interest to the tracer at the location of the measurement. This work describes field tests conducted in an air field in Fort Collins, CO to evaluate a tracer release and detection system. Acetylene (tracer gas) and methane (emission from potential source) have been released from a custom made manifold system. A PICARRO G2203 analyzer (using cavity ring down spectroscopy) and a mobile kit A0941 have been deployed on a vehicle for the downwind measurements. The emissions are measured downwind of the source and the tracer ratio method is used to calculate the emissions of methane. The measured and calculated values have been compared. Additionally, silonite-coated canisters have been used for collection and analysis of acetylene to further validate the setup. This system has been evaluated for sensitivity, accuracy and response time through a series of controlled tracer and methane releases under various meteorological conditions. The results from these tests and error analysis for the system are presented and discussed.

  14. Sexual system, sex ratio, and group living in the shrimp Thor amboinensis (De Man): relevance to resource-monopolization and sex-allocation theories.

    PubMed

    Baeza, J A; Piantoni, C

    2010-10-01

    The sexual system of the symbiotic shrimp Thor amboinensis is described, along with observations on sex ratio and host-use pattern of different populations. We used a comprehensive approach to elucidate the previously unknown sexual system of this shrimp. Dissections, scanning electron microscopy, size-frequency distribution analysis, and laboratory observations demonstrated that T. amboinensis is a protandric hermaphrodite: shrimp first mature as males and change into females later in life. Thor amboinensis inhabited the large and structurally heterogeneous sea anemone Stichodactyla helianthus in large groups (up to 11 individuals) more frequently than expected by chance alone. Groups exhibited no particularly complex social structure and showed male-biased sex ratios more frequently than expected by chance alone. The adult sex ratio was male-biased in the four separate populations studied, one of them being thousands of kilometers apart from the others. This study supports predictions central to theories of resource monopolization and sex allocation. Dissections demonstrated that unusually large males were parasitized by an undescribed species of isopod (family Entoniscidae). Infestation rates were similarly low in both sexes (?11%-12%). The available information suggests that T. amboinensis uses pure search promiscuity as a mating system. This hypothesis needs to be formally tested with mating behavior observations and field measurements on the movement pattern of both sexes of the species. Further detailed studies on the lifestyle and sexual system of all the species within this genus and the development of a molecular phylogeny are necessary to elucidate the evolutionary history of gender expression in the genus Thor. PMID:20972260

  15. Determination of pumper truck intervention ratios in zones with high fire potential by using geographical information system

    NASA Astrophysics Data System (ADS)

    Aricak, Burak; Kucuk, Omer; Enez, Korhan

    2014-01-01

    Fighting forest fires not only depends on the forest type, topography, and weather conditions, but is also closely related to the technical properties of fire-fighting equipment. Firefighting is an important part of fire management planning. However, because of the complex nature of forests, creating thematic layers to generate potential fire risk maps is difficult. The use of remote sensing data has become an efficient method for the discrete classification of potential fire risks. The study was located in the Central District of the Kastamonu Regional Forest Directorate, covering an area of 24,320 ha, 15,685 ha of which is forested. On the basis of stand age, crown closure, and tree species, the sizes and distributions of potential fire risk zones within the study area were determined using high-resolution GeoEye satellite imagery and geographical information system data. The status of pumper truck intervention in zones with high fire risk and the sufficiency of existing forest roads within an existing forest network were discussed based on combustible matter characteristics. Pumper truck intervention was 83% for high-risk zones, 79% for medium-risk zones, and 78% for low-risk zones. A pumper truck intervention area map along existing roads was also created.

  16. A complementary method to CD4 counting: measurement of CD4+/CD8+ T lymphocyte ratio in a tandem affinity microfluidic system.

    PubMed

    Li, Wenjie; Gao, Yan; Pappas, Dimitri

    2015-12-01

    We describe a tandem affinity microfluidic separation that measures the ratio of CD4+/CD8+ T lymphocytes from blood samples. It is performed by injecting 2?L of lysed blood samples at 1800-2700cells?L(-1) into a microfluidic device containing two serially linked affinity regions, followed with a stop flow incubation that captures CD4+/CD8+ T lymphocytes on the corresponding affinity regions. Fluorophore conjugated antibodies are then injected at a controlled shear stress of 1.7dyn cm(-2) to label target cells while eluting non-specific cells; and at last the CD4/CD8 ratio is calculated after the cell enumeration. The ratio of CD4+/CD8+ T lymphocytes achieved by our tandem affinity microfluidic system was in close agreement with that performed using conventional flow cytometry (R (2) ?=?0.97) over a wide range (0.4-2.5) that covered the reference values from immune deficient patients to healthy people. This approach may represent an inexpensive and powerful tool in diagnosis of immunodeficiency disorders including HIV or mycobacterium tuberculosis. PMID:26559198

  17. Self-forced evolutions of an implicit rotating source: A natural framework to model comparable and intermediate mass-ratio systems from inspiral through ringdown

    NASA Astrophysics Data System (ADS)

    Huerta, E. A.; Kumar, Prayush; Gair, Jonathan R.; McWilliams, Sean T.

    2014-07-01

    We develop a waveform model to describe the inspiral, merger and ringdown of binary systems with comparable and intermediate mass ratios. This model incorporates first-order conservative self-force corrections to the energy and angular momentum, which are valid in the strong-field regime [S. Akcay et al., Phys. Rev. D 86, 104041 (2012)]. We model the radiative part of the self-force by deriving second-order radiative corrections to the energy flux. These corrections are obtained by minimizing the phase discrepancy between our self-force model and the effective one body model [Y. Pan et al., Phys. Rev. D 84, 124052 (2011) and T. Damour et al., Phys. Rev. D 87, 084035 (2013)] for a variety of mass ratios. We show that our model performs substantially better than post-Newtonian approximants currently used to model neutron star-black hole mergers from early inspiral to the innermost stable circular orbit. In order to match the late inspiral evolution onto the plunge regime, we extend the "transition phase" developed by Ori and Thorne Phys. Rev. D 62, 124022 (2000) by including finite mass-ratio corrections and modeling the orbital phase evolution using an implicit rotating source [J. G. Baker et al., Phys. Rev. D 78, 044046 (2008)]. We explicitly show that the implicit rotating source approach provides a natural transition from late-time radiation to ringdown that is equivalent to ringdown waveform modeling based on a sum of quasinormal modes.

  18. Application of European protocol in the evaluation of contrast-to-noise ratio and mean glandular dose for two digital mammography systems.

    PubMed

    Muhogora, W E; Devetti, A; Padovani, R; Msaki, P; Bonutti, F

    2008-01-01

    The performance of two digital mammography systems, Agfa CR75 and CRMM3 computed radiography (CR) and IMS Giotto MD direct digital radiography (DR), was assessed by applying a method recommended in the European protocol for quality control in mammography screening. The contrast-to-noise ratio (CNR) and mean glandular dose (MGD) values were measured and contrast detail (CD) analysis was performed. The CNRs for system CR were 21.9, 12.9, 9.5, 8.8, 7.4, 5.5 and 4.4 for 2, 3, 4, 4.5, 5, 6 and 7-cm polymenthylmethacrylate (PMMA) thickness, respectively. The respective CNRs for system DR were 10.4, 8.8, 6.3, 7.3, 7.2, 6.4 and 6.54. For the same phantom thickness sequence, the MGDs were 0.7, 1.1, 1.3, 1.6, 1.9, 2.5 and 3.4 mGy for system CR, whereas they were 0.7, 1.2, 1.1, 1.3, 1.8, 3.5 and 3.9 mGy for system DR. The CNR and MGD results satisfactorily correlate with CD analysis results. The MGD values compare well with the values recommended in the European protocol. Despite being simple, CNR and MGD can provide an effective system for performance assessment and constancy checks for related optimisations. PMID:18283065

  19. Sixteen Years of Ulysses Interstellar Dust Measurements in the Solar System. I. Mass Distribution and Gas-to-dust Mass Ratio

    NASA Astrophysics Data System (ADS)

    Krüger, Harald; Strub, Peter; Grün, Eberhard; Sterken, Veerle J.

    2015-10-01

    In the early 1990s, contemporary interstellar dust penetrating deep into the heliosphere was identified with the in situ dust detector on board the Ulysses spacecraft. Between 1992 and the end of 2007 Ulysses monitored the interstellar dust stream. The interstellar grains act as tracers of the physical conditions in the local interstellar medium (ISM) surrounding our solar system. Earlier analyses of the Ulysses interstellar dust data measured between 1992 and 1998 implied the existence of a population of “big” interstellar grains (up to 10-13 kg). The derived gas-to-dust-mass ratio was smaller than the one derived from astronomical observations, implying a concentration of interstellar dust in the very local ISM. In this paper we analyze the entire data set from 16 yr of Ulysses interstellar dust measurements in interplanetary space. This paper concentrates on the overall mass distribution of interstellar dust. An accompanying paper investigates time-variable phenomena in the Ulysses interstellar dust data, and in a third paper we present the results from dynamical modeling of the interstellar dust flow applied to Ulysses. We use the latest values for the interstellar hydrogen and helium densities, the interstellar helium flow speed of {v}{ISM∞ }=23.2 {km} {{{s}}}-1, and the ratio of radiation pressure to gravity, β, calculated for astronomical silicates. We find a gas-to-dust mass ratio in the local interstellar cloud of {R}{{g}/{{d}}}={193}-57+85, and a dust density of (2.1 ± 0.6) × 10-24 kg m-3. For a higher inflow speed of 26 {km} {{{s}}}-1, the gas-to-dust mass ratio is 20% higher, and, accordingly, the dust density is lower by the same amount. The gas-to-dust mass ratio derived from our new analysis is compatible with the value most recently determined from astronomical observations. We confirm earlier results that the very local ISM contains “big” (i.e., ≈1 μm sized) interstellar grains. We find a dust density in the local ISM that is a factor of three lower than values implied by earlier analyses.

  20. Can mean platelet volume and mean platelet volume/platelet count ratio be used as a diagnostic marker for sepsis and systemic inflammatory response syndrome?

    PubMed Central

    Ates, Selma; Oksuz, Haf?ze; Dogu, B?rsen; Bozkus, Fulsen; Ucmak, Hasan; Yan?t, Fadime

    2015-01-01

    Objectives: To determine whether the mean platelet volume (MPV) and MPV/platelet (PLT) values can be used in the study of sepsis and systemic inflammatory response syndrome (SIRS). Methods: In this retrospective case-controlled study, 69 sepsis, 69 SIRS patients, and 72 control group who were treated in the years 2012-2013 were reviewed, and both the MPV and MPV/PLT rates were evaluated in all groups at Kahramanmaras Sutcu Imam University Intensive Care Unit, Kahramanmaras, Turkey. Results: Statistically significant difference was found between sepsis, SIRS, and control groups when comparing the MPV and MPV/PLT ratio (p<0.05), and no significant difference was found between sepsis and SIRS groups in terms of MPV and MPV/PLT ratio (p>0.05). Mean platelet volume values for sepsis and control groups was 10.07/8.731 femtoliter (fL) (p=0.000), and 9.45/8.731 fL (p=0.000) for SIRS and control groups. In the group of sepsis patients, the MPV was found to be at cut-off 8.915, sensitivity 71%, and specificity 63.9%. In the group of patients with SIRS, MPV was found to be at cut-off 8.85, sensitivity 69.6%, and specificity 62.5%. For the MPV/PLT values, the specificity and sensitivity were found to be insignificant. Conclusion: This study shows that although there was no significant reduction in the PLT values between the sepsis and SIRS patients, the MPV and MPV/PLT ratio values were found to have significant differences. However, the specificity and sensitivity of the values were not reliable standard to be used as a test. PMID:26446329

  1. Neutral beam interlock system on TFTR using infrared pyrometry

    SciTech Connect

    Medley, S.S.; Kugel, H.W.; Kozub, T.A.; Lowrance, J.L.; Mastrocola, V.; Renda, G.; Young, K.M.

    1986-06-01

    Although the region of the TFTR vacuum vessel wall which is susceptible to damage by neutral beam strike is armored with a mosaic of TiC-clad POCO graphite titles, at power deposition levels above 2.5 kW/cm/sup 2/ the armor surface temperature exceeds 1200/sup 0/C within 250 ms and itself becomes susceptible to damage. In order to protect the wall armor, a neutral beam interlock system based on infrared pyrometry measurement of the armor surface temperature was installed on TFTR. For each beamline, a three-fiber-optic telescope views three areas of approx.30 cm diameter centered on the armor hot spots for the three ion sources. Each signal is fiber-optic coupled to a remote 900 nm pyrometer which feeds analog signals to the neutral beam interrupt circuits. The pyrometer interlock system is designed to interrupt each of the twelve ion sources independently within 10 ms of the temperature exceeding a threshold settable in the range of 500 to 2300/sup 0/C. A description of the pyrometer interlock system and its performance will be presented.

  2. Elucidating microbial processes in nitrate- and sulfate-reducing systems using sulfur and oxygen isotope ratios: The example of oil reservoir souring control

    NASA Astrophysics Data System (ADS)

    Hubert, Casey; Voordouw, Gerrit; Mayer, Bernhard

    2009-07-01

    Sulfate-reducing bacteria (SRB) are ubiquitous in anoxic environments where they couple the oxidation of organic compounds to the production of hydrogen sulfide. This can be problematic for various industries including oil production where reservoir "souring" (the generation of H 2S) requires corrective actions. Nitrate or nitrite injection into sour oil fields can promote SRB control by stimulating organotrophic nitrate- or nitrite-reducing bacteria (O-NRB) that out-compete SRB for electron donors (biocompetitive exclusion), and/or by lithotrophic nitrate- or nitrite-reducing sulfide oxidizing bacteria (NR-SOB) that remove H 2S directly. Sulfur and oxygen isotope ratios of sulfide and sulfate were monitored in batch cultures and sulfidic bioreactors to evaluate mitigation of SRB activities by nitrate or nitrite injection. Sulfate reduction in batch cultures of Desulfovibrio sp. strain Lac15 indicated typical Rayleigh-type fractionation of sulfur isotopes during bacterial sulfate reduction (BSR) with lactate, whereas oxygen isotope ratios in unreacted sulfate remained constant. Sulfur isotope fractionation in batch cultures of the NR-SOB Thiomicrospira sp. strain CVO was minimal during the oxidation of sulfide to sulfate, which had ?18O SO4 values similar to that of the water-oxygen. Treating an up-flow bioreactor with increasing doses of nitrate to eliminate sulfide resulted in changes in sulfur isotope ratios of sulfate and sulfide but very little variation in oxygen isotope ratios of sulfate. These observations were similar to results obtained from SRB-only, but different from those of NR-SOB-only pure culture control experiments. This suggests that biocompetitive exclusion of SRB took place in the nitrate-injected bioreactor. In two replicate bioreactors treated with nitrite, less pronounced sulfur isotope fractionation and a slight decrease in ?18O SO4 were observed. This indicated that NR-SOB played a minor role during dosing with low nitrite and that biocompetitive exclusion was the major process. The results demonstrate that stable isotope data can contribute unique information for understanding complex microbial processes in nitrate- and sulfate-reducing systems, and offer important information for the management of H 2S problems in oil reservoirs and elsewhere.

  3. New hybrid peak-to-average power ratio reduction technique based on carrier interferometry codes and companding technique for optical direct-detection orthogonal frequency division multiplexing system

    NASA Astrophysics Data System (ADS)

    Maivan, Lap; He, Jing; Chen, Ming; Mangone, Fall; Chen, Lin

    2014-08-01

    In direct-detection optical orthogonal frequency division multiplexing (OFDM) systems, the high peak-to-average power ratio (PAPR) will cause nonlinear effects in both electrical and optical devices and optical fiber transmission when the nonlinear amplifiers are employed. A new hybrid technique based on carrier interferometry codes and companding transform has been proposed and experimentally demonstrated to reduce the high PAPR in an optical direct-detection optical OFDM system. The proposed technique is then experimentally demonstrated and the results show the effectiveness of the new method. The PAPR of the hybrid signal has been reduced by about 5.7 dB when compared to the regular system at a complementary cumulative distribution function of 10-4. At a bit error rate of 10-4, after transmission over 100-km single-mode fiber with a ? of 2, the receiver sensitivity is improved by 3.7, 4.2, and 5 dB with launch powers of 3, 6, and 9 dBm, respectively.

  4. Time-resolved stereo PIV measurements of the horseshoe vortex system at multiple locations in a low-aspect-ratio pin-fin array

    NASA Astrophysics Data System (ADS)

    Anderson, Corey D.; Lynch, Stephen P.

    2016-01-01

    Pin-fin arrays are a type of cooling feature found in heat exchangers, with elements (generally cylindrical or square) that span between two endwalls. Flow around the pin-fins generates highly turbulent mixing that increases convective heat transfer from the pins to the cooling flow. At the junction of a pin-fin and the endwall, a complex flow known as the horseshoe vortex (HSV) system is present. Although the HSV is a well-studied phenomenon, its behavior is not understood in the highly turbulent flow of a pin-fin array. Furthermore, the presence of close confining endwalls for low-aspect-ratio (short) pin-fins may have an impact on HSV dynamics. The present study utilized time-resolved stereo particle image velocimetry to examine the fluid dynamics of the HSV system in rows 1, 3, and 5 of a low-aspect-ratio pin-fin array, for a range of Reynolds numbers. In the first row, instantaneous flowfields indicated a clearly defined HSV at the leading edge, with dynamics similar to previous studies of bluff-body junction flows. The time-averaged HSV system moved closer to the pin with increasing Reynolds number, with more concentrated vorticity and turbulent kinetic energy (TKE). For downstream rows, there was a significant increase in the amount of mid-channel vorticity, with levels on the same order as the value in the core of the HSV. The time-averaged HSV system in downstream rows showed minimal variation with respect to either Reynolds number or row location. Regions of maximum streamwise and wall-normal turbulent fluctuations around the HSV were a result of its quasiperiodic oscillation between so-called backflow and zero-flow modes, which were present even in downstream rows despite the extremely high mid-channel turbulence. In the downstream rows, normalized TKE across the entire field of view decreased with increased Reynolds number, likely due to dissipation rates proportionally outpacing increases in mean channel velocity and Reynolds number. The flowfield results from this study corroborate prior findings from heat transfer measurements that indicate a fully developed condition is established at around the fifth row in an array.

  5. High ratio recirculating gas compressor

    DOEpatents

    Weinbrecht, J.F.

    1989-08-22

    A high ratio positive displacement recirculating rotary compressor is disclosed. The compressor includes an integral heat exchanger and recirculation conduits for returning cooled, high pressure discharge gas to the compressor housing to reducing heating of the compressor and enable higher pressure ratios to be sustained. The compressor features a recirculation system which results in continuous and uninterrupted flow of recirculation gas to the compressor with no direct leakage to either the discharge port or the intake port of the compressor, resulting in a capability of higher sustained pressure ratios without overheating of the compressor. 10 figs.

  6. High ratio recirculating gas compressor

    DOEpatents

    Weinbrecht, John F. (601 Oakwood Pl., NE., Albuquerque, NM 87123)

    1989-01-01

    A high ratio positive displacement recirculating rotary compressor is disclosed. The compressor includes an integral heat exchanger and recirculation conduits for returning cooled, high pressure discharge gas to the compressor housing to reducing heating of the compressor and enable higher pressure ratios to be sustained. The compressor features a recirculation system which results in continuous and uninterrupted flow of recirculation gas to the compressor with no direct leakage to either the discharge port or the intake port of the compressor, resulting in a capability of higher sustained pressure ratios without overheating of the compressor.

  7. The Golden Ratio

    ERIC Educational Resources Information Center

    Hyde, Hartley

    2004-01-01

    The Golden Ratio is sometimes called the "Golden Section" or the "Divine Proportion", in which three points: A, B, and C, divide a line in this proportion if AC/AB = AB/BC. "Donald in Mathmagicland" includes a section about the Golden Ratio and the ratios within a five-pointed star or pentagram. This article presents two computing exercises that

  8. Application of the laser ablation Mg/Ca ratio from planktonic foraminifera to paleotemperature and stratification reconstructions: example from the Cabo Frio Upwelling System (Brazil) during the Holocene

    NASA Astrophysics Data System (ADS)

    Villela De Oliveira Lessa, D.; Albuquerque, A. L.; Turcq, B.

    2014-12-01

    This study aimed to reconstruct paleotemperatures through Mg/Ca ratio in Globigerinoides ruber and Globigerina bulloides using the laser ablation and ICP-MS technique (LA-ICP-MS) in a core sampled from a western boundary upwelling system. The mean Mg/Ca ratio from the last three chambers was measured in seven tests of G. ruber and G. bulloides .Paleotemperatures were reconstructed using the equations of Anand et al (2003) for G. ruber and Mashiotta et al. (1999) for G. bulloides. The last chamber from G. ruber recorded Mg/Ca values which temperatures varied between 19 and 22C. The temperatures obtained from the last chamber were lower than from the others two chambers, which temperatures varied between 24 and 26C. This difference suggests the specie migrate to cold deeper waters during the calcification of the last chamber. It indicates that reconstructions based on the last chamber confronted with the mean of others two chambers could be used to estimate past water stratification. The Mg/Ca values of G. bulloides were not so different among the chambers, generating paleotemperatures between 18 and 22C. However, G. bulloides's individual variation coefficient was higher (14 - 48%) than G. ruber (12 - 28%), indicating the specie tolerates higher thermic amplitude due to its behavior related to searching by food. Cold surface waters and warmer sub-surface waters occurred between 9.0 and 7.2 kyr BP and the opposite occurring after 7.2 ka BP. The G. bulloides's estimated cold episodes were marked before 8,0 ka BP, between 6.0 and 5.5 kyr BP, between 4.5 and 4.0 kyr BP and after 2.0 ka BP, which could be associated to upwelling intensity. The divergence of G. bulloides and G. ruber's last chamber paleotemperatures suggest the species may not inhabit during the same time, which demands caution in stratification reconstructions based on these two species.

  9. Altered Th17 cells and Th17/regulatory T-cell ratios indicate the subsequent conversion from undifferentiated connective tissue disease to definitive systemic autoimmune disorders.

    PubMed

    Szodoray, Peter; Nakken, Britt; Barath, Sandor; Csipo, Istvan; Nagy, Gabor; El-Hage, Fadi; Osnes, Liv T; Szegedi, Gyula; Bodolay, Edit

    2013-12-01

    A shift in the balance between Th17-cells and regulatory T-cells (Treg) is an important feature of systemic autoimmune diseases (SAID), and may also contribute to their development. Hereby, we assessed the distribution of peripheral Th17 and Treg-cells in patients with undifferentiated connective tissue disease (UCTD), the forerunner of SAIDs and followed these parameters during the development towards definitive SAIDs. Fifty-one UCTD patients were investigated and followed-up for 3 years. Flow cytometry was used to identify and follow three cell-populations: Th17-cells (CD4+IL-17+ T-cells), natural regulatory T-cells (CD4(+)CD25(bright)FoxP3(+); nTregs) and IL-10 producing Type-1 regulatory T-cells (CD4+IL-10+ T-cells; Tr1). Altogether 37.3% of these patients progressed into SAIDs. Th17-cells were increased in UCTD vs. controls, which further increased in those, whom developed SAIDs eventually. The Th17/nTreg ratio gradually increased from controls through UCTD patients, reaching the highest values in SAID-progressed patients. Regarding the Th17/Tr1 ratios, a similar tendency was observed moreover Th17/Tr1 could distinguish between UCTD patients with, or without subsequent SAID progression in a very early UCTD stage. Various immunoserological markers showed association with Th17 and Th17/nTreg at baseline, indicating the consecutive development of a distinct SAID. The derailed Th17/Treg balance may contribute to disease progression therefore could function as a prognostic marker. PMID:23974054

  10. Influence of Ni/Mo ratio on structural and electrical properties of double perovskite system Sr2Ni1+ x Mo1- x O6- ?

    NASA Astrophysics Data System (ADS)

    Kumar, Pravin; Singh, Nitish Kumar; Singh, Rajesh Kumar; Singh, Prabhakar

    2015-11-01

    Technologically important double perovskite system Sr2Ni1+ x Mo1- x O6- ? with x = 0.00, 0.05, 0.10, and 0.15 was prepared by solution combustion method. The structural and the Rietveld analysis of compositions revealed the formation of double perovskite tetragonal phase Sr2NiMoO6 with space group I4/m as a major phase. SrMoO4 and NiO were also observed as minor phases. Microstructural studies depicted the formation of uniform grains for all the samples. The average grain size was found to lie between the ranges of 1-4 ?m. XPS analysis of the synthesized compositions showed the decreasing ratio of Mo5+ to Mo6+ ions in the system with increasing Ni content, which played an important role in the conduction mechanism. The thermal expansion coefficient (TEC) of all compositions indicated that it is more compatible to the TEC of standard electrolytes. The electrical conductivity for all the compositions was studied using impedance spectroscopy in the temperature range 200-600 C. Composition with x = 0.05 showed better electrical conductivity with good catalytic activity.

  11. Study on the improved peak-to-average-power ratio reduction technology based on the partial transmission sequences method in optical orthogonal frequency division multiplexing systems

    NASA Astrophysics Data System (ADS)

    Jianguo, Yuan; Zhangchao, Li; Yunxia, Hu; Quanliang, Sheng; Jinzhao, Lin; Yu, Pang

    2014-07-01

    According to the defect of the high peak-to-average-power ratio (PAPR) in optical orthogonal frequency division multiplexing (OFDM) systems, the PAPR reduction technology based on the partial transmission sequences (PTS) method has been deeply studied. An improved enhanced-iterative-algorithm-PTS (EIA-PTS) technology is proposed. The proposed EIA-PTS technology, compared with the original PTS (O-PTS), can reduce the computational complexity. The simulation analysis shows that the computational complexity of the O-PTS method grows exponentially with an increase in the number of both subblocks and phase factors, while the computational complexity of the EIA-PTS technology basically remains stable and is lower than that of the O-PTS method. On the basis of the proposed EIA-PTS technology, an improved EIA-PTS-Clipping combined PAPR reduction technology that combines EIA-PTS technology with clipping technology is proposed. The simulation result shows the proposed EIA-PTS-Clipping combined PAPR reduction technology, compared with the previous proposed EIA-PTS technology, can further improve the PAPR reduction performance and has a higher application value because it can have a better tradeoff between the bit error rate performance and PAPR reduction effect for optical OFDM systems.

  12. An analytical system for studying the stable isotopes of carbon monoxide using continuous flow-isotope ratio mass spectrometry (CF-IRMS)

    NASA Astrophysics Data System (ADS)

    Pathirana, S. L.; van der Veen, C.; Popa, M. E.; Rckmann, T.

    2015-02-01

    In the atmosphere, carbon monoxide (CO) is the major sink for the hydroxyl radical (OH •), has multiple anthropogenic and natural sources and considerable spatial and seasonal variability. Measurements of CO isotopic composition are useful in constraining the strengths of its individual source and sink processes and thus its global cycle. A fully automated system for ?13C and ?18O analysis has been developed to extract CO from an air sample, convert CO into carbon dioxide (CO2) using the Schtze reagent, and then determine the isotopic composition in an isotope ratio mass spectrometer (IRMS). The entire system is continuously flushed with high-purity helium (He), the carrier gas. The blank signal of the Schtze reagent is only 1-3% of the typical sample size. The repeatability is 0.1 for ?13C and 0.2 for ?18O. The peak area allows simultaneous determination of the mole fraction with an analytical repeatability of ~0.7 nmol mol-1 for 100 mL of typical ambient air (185.4 nmol mol-1 of CO). A single, automated, measurement is performed in 18 min, so multiple measurements can be combined conveniently to improve precision.

  13. 230Th/232Th activity ratios as a chronological marker complementing 210Pb dating in an estuarine system affected by industrial releases.

    PubMed

    San Miguel, E G; Bolvar, J P; Garca-Tenorio, R; Martn, J E

    2001-01-01

    The main purpose of this research is to show the usefulness of the 230Th/232Th activity ratios as a chronological marker that can be helpful in the dating of sediment cores collected from an estuarine system located in the south west of Spain highly polluted by wastes from fertilizer plants. These wastes, being released for 30 years, and enriched in radionuclides from the uranium series including 210Pb, invalidate the application of the 210Pb dating technique in full extent to the sediment cores collected in this estuary. However, the evaluation and the interpretation of both 210Pb and 230Th/232Th profiles allows the determination of average sedimentation rates in different parts of the cores, contaminated and noncontaminated zone, that agree in the case analysed in this research. Through this approach, a confident chronology covering the last century, which is essential to analyse and reconstruct the historical evolution of other pollutants in this heavily contaminated system can be established. PMID:11291442

  14. Updated thinking on positivity ratios.

    PubMed

    Fredrickson, Barbara L

    2013-12-01

    This article presents my response to the article by Brown, Sokal, and Friedman (2013), which critically examined Losada's conceptual and mathematical work (as presented in Losada, 1999; Losada & Heaphy, 2004; and Fredrickson & Losada; 2005) and concluded that mathematical claims for a critical tipping point positivity ratio are unfounded. In the present article, I draw recent empirical evidence together to support the continued value of computing and seeking to elevate positivity ratios. I also underscore the necessity of modeling nonlinear effects of positivity ratios and, more generally, the value of systems science approaches within affective science and positive psychology. Even when scrubbed of Losada's now-questioned mathematical modeling, ample evidence continues to support the conclusion that, within bounds, higher positivity ratios are predictive of flourishing mental health and other beneficial outcomes. PMID:23855895

  15. Backscatter-to-Extinction Ratios in the Top Layers of Tropical Mesoscale Convective Systems and in Isolated Cirrus from LITE Observations

    NASA Technical Reports Server (NTRS)

    Platt, C. M. R.; Winker, D. M.; Vaughan, M. A.; Miller, S. D.

    1999-01-01

    Cloud-integrated attenuated backscatter from observations with the Lidar In-Space Technology Experiment (LITE) was studied over a range of cirrus clouds capping some extensive mesoscale convective systems (MCSS) in the Tropical West Pacific. The integrated backscatter when the cloud is completely attenuating, and when corrected for multiple scattering, is a measure of the cloud particle backscatter phase function. Four different cases of MCS were studied. The first was very large, very intense, and fully attenuating, with cloud tops extending to 17 km and a maximum lidar pulse penetration of about 3 km. It also exhibited the highest integrated attenuated isotropic backscatter, with values in the 532-nm channel of up to 2.5 near the center of the system, falling to 0.6 near the edges. The second MCS had cloud tops that extended to 14.8 km. Although MCS2 was almost fully attenuating, the pulse penetration into the cloud was up to 7 km and the MCS2 had a more diffuse appearance than MCS1. The integrated backscatter values were much lower in this system but with some systematic variations between 0.44 and 0.75. The third MCS was Typhoon Melissa. Values of integrated backscatter in tt-ds case varied from 1.64 near the eye of the typhoon to between 0.44 and 1.0 in the areas of typhoon outflow and in the 532-nm channel. Mean pulse penetration through the cloud top was 2-3 km, the lowest penetration of any of the systems. The fourth MCS consisted of a region of outflow from Typhoon Melissa. The cloud was semitransparent for more than half of the image time. During that time, maximum cloud depth was about 7 km. The integrated backscatter varied from about 0.38 to 0.63 in the 532-nm channel when the cloud was fully attenuating. In some isolated cirrus between the main systems, a plot of integrated backscatter against one minus the two-way transmittance gave a linear dependence with a maximum value of 0.35 when the clouds were fully attenuating. The effective backscatter-to-extinction ratios, when allowing for different multiple-scattering factors from space, were often within the range of those observed with ground-based lidar. Exceptions occurred near the centers of the most intense convection, where values were measured that were considerably higher than those in cirrus observed from the surface. In this case, the values were more compatible with theoretical values for perfectly formed hexagonal columns or plates. The large range in theoretically calculated back- scatter-to-extinction ratio and integrated multiple-scattering factor precluded a closer interpretation in terms of cloud microphysics.

  16. Aspartate aminotransferase-lymphocyte ratio index and systemic immune-inflammation index predict overall survival in HBV-related hepatocellular carcinoma patients after transcatheter arterial chemoembolization.

    PubMed

    Yang, Zongguo; Zhang, Jianliang; Lu, Yunfei; Xu, Qingnian; Tang, Bozong; Wang, Qiang; Zhang, Wensi; Chen, Shishi; Lu, Lingqing; Chen, Xiaorong

    2015-12-15

    It has been suggested that lymphocytes play central roles in host antitumor immune responses and control cancer outcome. We reviewed the clinical parameters of 189 hepatocellular carcinoma (HCC) patients and investigated the prognostic significance of lymphocyte-related scores in HCC patients following transcatheter arterial chemoembolization (TACE). Survival analysis revealed that an elevated aspartate aminotransferase-lymphocyte ratio index (ALRI) > 57 and a systemic immune-inflammation index (SII) > 300 were negatively associated with overall survival in HBV-related HCC (HR = 2.181, P = 0.003 and HR = 2.453, P = 0.003; respectively). Spearman chi-square analysis showed that ALRI had a specificity of 82.4% and that SII index had a sensitivity of 71.9% for HCC overall survival. ALRI and SII had negative predictive values of 74.6% and 80%, respectively for HCC overall survival. Additionally, Barcelona Clinic Liver Cancer (BCLC) stage C patients had significantly higher ALRI and SII scores (both P < 0.0001) and poorer overall survival (HR = 3.618, P < 0.001). Additionally, HCC patients with portal vein tumor thrombosis (PVTT) had higher ALRI and SII scores (P < 0.0001 and P = 0.0059, respectively). In conclusion, as noninvasive, low cost, easily assessable and reproducible parameters, elevated ALRI and SII should be used as negative predictive factors for overall survival in HBV-related HCC in clinical practice. PMID:26506519

  17. Aspartate aminotransferase-lymphocyte ratio index and systemic immune-inflammation index predict overall survival in HBV-related hepatocellular carcinoma patients after transcatheter arterial chemoembolization

    PubMed Central

    Yang, Zongguo; Zhang, Jianliang; Lu, Yunfei; Xu, Qingnian; Tang, Bozong; Wang, Qiang; Zhang, Wensi; Chen, Shishi; Lu, Lingqing; Chen, Xiaorong

    2015-01-01

    It has been suggested that lymphocytes play central roles in host antitumor immune responses and control cancer outcome. We reviewed the clinical parameters of 189 hepatocellular carcinoma (HCC) patients and investigated the prognostic significance of lymphocyte-related scores in HCC patients following transcatheter arterial chemoembolization (TACE). Survival analysis revealed that an elevated aspartate aminotransferase-lymphocyte ratio index (ALRI) > 57 and a systemic immune-inflammation index (SII) > 300 were negatively associated with overall survival in HBV-related HCC (HR = 2.181, P = 0.003 and HR = 2.453, P = 0.003; respectively). Spearman chi-square analysis showed that ALRI had a specificity of 82.4% and that SII index had a sensitivity of 71.9% for HCC overall survival. ALRI and SII had negative predictive values of 74.6% and 80%, respectively for HCC overall survival. Additionally, Barcelona Clinic Liver Cancer (BCLC) stage C patients had significantly higher ALRI and SII scores (both P < 0.0001) and poorer overall survival (HR = 3.618, P < 0.001). Additionally, HCC patients with portal vein tumor thrombosis (PVTT) had higher ALRI and SII scores (P < 0.0001 and P = 0.0059, respectively). In conclusion, as noninvasive, low cost, easily assessable and reproducible parameters, elevated ALRI and SII should be used as negative predictive factors for overall survival in HBV-related HCC in clinical practice. PMID:26506519

  18. Automated temperature measuring system for coke-oven battery heating equipment

    SciTech Connect

    Bukreev, A.V.; Khromov, N.A.; Volokita, G.I.

    1992-12-31

    Work is in progress at the Avdeevka C&CW on the introduction of computer technology in the control of coal preparation and carbonization processes. One urgent problem at present is the automated input of information into the computers. Carbonization process control requires temperature measurements to be made by the gas plant attendants every shift, with the aid of {open_quotes}Promin{close_quotes} pyrometers. The readings take a considerable time to record and process, and distract the operator`s attention from his main duties, and the possibility of errors can never be excluded. Since the accuracy of the readings has a significant influence on process control, while the readings are subsequently used in a mathematical model of the carbonization process, it has become necessary to develop an automated system for recording temperature readings, on the basis of the {open_quotes}Promin{close_quotes} pyrometer. 2 refs., 1 fig.

  19. Detecting isotopic ratio outliers

    SciTech Connect

    Bayne, C.K.; Smith, D.H.

    1985-01-01

    An alternative method is proposed for improving isotopic ratio estimates. This method mathematically models pulse-count data and uses iterative reweighted Poisson regression to estimate model parameters to calculate the isotopic ratios. This computer-oriented approach provides theoretically better methods than conventional techniques to establish error limits and to identify outliers. 6 refs., 3 figs., 3 tabs.

  20. Poisson Ratios of Polycrystals

    NASA Astrophysics Data System (ADS)

    Milstein, Frederick; Budek, Andrew M.

    1987-08-01

    Poisson ratios of fee and bcc polycrystals are calculated for a variety of atomic models and the theoretical results are compared with experiment. In contrast with previously reported results, it is found that an accurate description of polycrystalline Poisson ratios of metals is obtained from the model in which the binding energy Ebind consists of a structure dependent part Estr and a volume dependent part Evol. Investigations are made of the general, inherent abilities of various subsets of this model to describe experimental polycrystalline Poisson ratios; these subsets include the Cauchy model (i.e. Evol is neglected in Ebind) and the Milstein-Rasky model (i.e. the volume dependent contribution to the bulk modulus ?vol is neglected). In addition, specific com putations of polycrystalline Poisson ratios are made for the complete families of bcc and fcc Morse function (Cauchy) crystals and for (non-Cauchy) models (simplified forms of which are suggested by pseudopotential theory for the noble metals).

  1. Further stratification of patients with multiple myeloma by International Staging System in combination with ratio of serum free ? to ? light chains.

    PubMed

    Xu, Yan; Sui, Weiwei; Deng, Shuhui; An, Gang; Wang, Yafei; Xie, Zhenqing; Yao, Hongjing; Zhu, Guoqing; Zou, Dehui; Qi, Junyuan; Hao, Mu; Zhao, Yaozhong; Wang, Jianxiang; Chen, Tao; Qiu, Lugui

    2013-01-01

    The serum free light chain (sFlc) levels were measured for 122 Chinese patients with newly diagnosed symptomatic multiple myeloma (NDSMM), and ?/? ratios (rFlc) were calculated. The data were analyzed for the roles of sFlc and rFlc in the diagnosis and prognosis of MM. Abnormal sFlc and/or rFlc were detected in 99.2% of patients, demonstrating that the FLC assay is much more sensitive than the commonly used methods. Baseline sFlc and rFlc successfully predicted the overall survival (OS). The median OS was not reached (NR) versus 23 months for the low sFLC group (sFLC-? < 180 mg/L or sFLC-? < 592.5 mg/L) and high sFLC group (sFLC-? ? 180 mg/L or sFLC-? ? 592.5 mg/L) (p = 0.001), and NR versus 21 months for the low rFLC group (0.04 ? rFLC ? 25) and high rFLC group (p < 0.001), respectively. Interestingly, the significant differences in OS between the low and high rFLC groups were not changed by bortezomib chemotherapy. In addition, patients were further stratified by three novel poor-prognosis factors (?(2)-microglobulin [?2-MG] > 3.5 mg/L, albumin [ALB] < 35 g/L, rFLC > 25 or rFLC < 0.04) that were developed from combination of the rFlc with the International Staging System (ISS): the low risk group (no factor), the low-intermediate risk group (one factor), the high-intermediate risk group (two factors) and the high risk group (three factors). The median OS for those groups was NR, NR, 24 months and 13 months, respectively (p < 0.05). In conclusion, the sFLC assay was highly sensitive in the diagnosis of MM in Chinese patients. The prognostic potential of the ISS may be improved with the addition of rFLC. PMID:22712834

  2. Coupled Ge/Si and Ge isotope ratios as geochemical tracers of seafloor hydrothermal systems: Case studies at Loihi Seamount and East Pacific Rise 950?N

    NASA Astrophysics Data System (ADS)

    Escoube, Raphaelle; Rouxel, Olivier J.; Edwards, Katrina; Glazer, Brian; Donard, Olivier F. X.

    2015-10-01

    Germanium (Ge) and Silicon (Si) exhibit similar geochemical behavior in marine environments but are variably enriched in seafloor hydrothermal fluids relative to seawater. In this study, Ge isotope and Ge/Si ratio systematics were investigated in low temperature hydrothermal vents from Loihi Seamount (Pacific Ocean, 1854?N, 15515?W) and results were compared to high-temperature vents from the East Pacific Rise (EPR) at 950?N. Loihi offers the opportunity to understand contrasting Ge and Si behavior in low temperature seafloor hydrothermal systems characterized by abundant Fe oxyhydroxide deposition at the seafloor. The results show that both Ge/Si and ?74/70Ge in hydrothermal fluids are fractionated relative to the basaltic host rocks. The enrichment in Ge vs. Si relative to fresh basalts, together with Ge isotope fractionation (?74/70Gefluid-basalt up to 1.15 at EPR 950?N and 1.64 at Loihi) are best explained by the precipitation of minerals (e.g. quartz and Fe-sulfides) during higher temperature seawater-rock reactions in the subsurface. The study of Fe-rich hydrothermal deposits at Loihi, largely composed of Fe-oxyhydroxides, shows that Ge isotopes are also fractionated upon mineral precipitation at the seafloor. We obtained an average Ge isotope fractionation factor between Fe-oxyhydroxide (ferrihydrite) and dissolved Ge in the fluid of -2.0 0.6 (2sd), and a maximum value of -3.6 0.6 (2sd), which is consistent with recent theoretical and experimental studies. The study of a hydrothermal chimney at Bio 9 vent at EPR 950?N also demonstrates that Ge isotopes are fractionated by approximately -5.6 0.6 (2sd) during precipitation of metal sulfides under hydrothermal conditions. Using combined Ge/Si and estimated Ge isotope signatures of Ge sinks and sources in seawater, we propose a preliminary oceanic budget of Ge which reveals that an important sink, referred as the "missing Ge sink", may correspond to Ge sequestration into authigenic Fe-oxyhydroxides in marine sediments. This study shows that combining Ge/Si and ?74/70Ge systematics provides a useful tool to trace hydrothermal Ge and Si sources in marine environments and to understand formation processes of seafloor hydrothermal deposits.

  3. Characterizing Nitrous Oxide (N2O) Emissions over a Wheat-based Cropping System in the Northwest United States Using the Modified Bowen Ratio Technique and Static Chambers

    NASA Astrophysics Data System (ADS)

    Waldo, Sarah; Kostyanovsky, Kirill; O'Keeffe, Patrick; Pressley, Shelley; Huggins, Dave; Stockle, Claudio; Lamb, Brian

    2015-04-01

    Nitrous oxide (N2O) is a potent greenhouse gas and ozone depleting substance. Agricultural soils are the primary source of N2O, which is created as a by-product of soil microbial processes. The production and emission of N2O is characterized by high spatial and temporal variability, or "hot spots" and "hot moments". These behaviors, along with limitations in instrument sensitivity to N2O, are challenges in characterizing emissions. Many studies have monitored N2O emissions using either static chambers or micrometeorological measurements or the two methods together. The two techniques are complementary: chamber methods have a lower detection limit and are more reliable as their operation does not depend on atmospheric conditions, but may not capture spatial variability even with multiple chambers. Tower-based methods are subject to relatively high data loss due to non-ideal conditions and to less sensitive detection limits, but have a larger measurement footprint and can characterize field-scale emissions. This study aims to characterize a long-term, field-scale N2O budget over two winter wheat fields located in the Inland Pacific Northwest of the United States, both in terms of an annual emission budget and in terms of understanding what causes hot moments. We combined continuous measurements of N2O emissions from a system of sixteen automated, static chambers with tower-based measurements of N2O fluxes. We used the modified Bowen ratio (MBR) technique with temperature as a tracer. Preliminary results indicate that freeze-thaw cycles in the winter make up a higher percentage of annual emissions than previously thought. Furthermore, comparison of the chamber results to the tower-based measurements imply that the chambers may be underestimating field-scale N2O fluxes because they are not adequately capturing hot spots of emissions. We are conducting ongoing work on how to integrate the two measurement techniques, as well as how the empirical measurements compare with other measures of N2O emissions for the region.

  4. Discrimination Level of Students' Ratio, Number of Students per Faculty Member and Article Scores Indicators According to Place of Turkish Universities in International Ranking Systems

    ERIC Educational Resources Information Center

    zkan, Metin

    2016-01-01

    The aim of this research is to determine classification in which the level of accuracy in Turkish universities rankings is detected by the international assessments according to the independent variables PhD students ratio, the number of students per faculty member and the article scores. The data of research were obtained from University Ranking

  5. Polaradiometric pyrometer in which the parallel and perpendicular components of radiation reflected from an unpolarized light source are equalized with the thermal radiation emitted from a measured object to determine its true temperature

    NASA Technical Reports Server (NTRS)

    Abtahi, Ali A. (Inventor)

    1995-01-01

    A radiation pyrometer for measuring the true temperature of a body is provided by detecting and measuring thermal radiation from the body based on the principle that the effects of angular emission I(sub 1) and reflection I(sub 2) on the polarization states p and s of radiation are complementary such that upon detecting the combined partial polarization state components I(sub p) =I(sub 1p) + I(sub 2p) and I(sub s)=I(sub 1s) + I(sub 2s) and adjusting the intensity of the variable radiation source of the reflected radiation I(sub 2) until the combined partial radiation components I(sub p) and I(sub s) are equal, the effects of emissivity as well as diffusivity of the surface of the body are eliminated, thus obviating the need for any post processing of brightness temperature data.

  6. Air/fuel ratio regulator

    SciTech Connect

    Simko, A.

    1980-07-22

    A description is given of an air/fuel ratio regulator for use with the fuel injection control system of an internal combustion engine of the spark ignition type having an air and exhaust gas (gas) induction passage open at one end to air at ambient pressure level and connected at its other end to the engine combustion chamber to be subject to manifold vacuum changes therein, a throttle valve rotatably mounted for movement across the passage to control the gas flow therethrough, exhaust gas recirculation (egr) passage means connecting engine exhaust gases to the induction passage above the closed position of the throttle valve, an egr flow control valve mounted in the egr passage means for movement between open and closed postions to control the volume of egr gas flow, an engine speed responsive positive displacement type fuel injection pump having a fuel flow output to the engine that varies in direct proportion to changes in engines speed to match fuel flow and mass airflow through the induction system of the engine over the entire speed and load range of the engine to maintain the intake mixture ratio of air to fuel constant, the pump having a fuel flow control lever movable to vary the fuel rate of flow, the regulator being characterized by engine manifold vacuum responsive first servo means operably connected to the fuel control lever for maintaining a constant air/fuel (A/F) ratio by changing fuel output as a function of changing manifold vacuum and air flow upon opening of the throttle valve, a fuel enrichment control lever operably connected to the pump control lever and movable to modify the position of the pump lever dictated by the first servo means to change the A/F ratio, and further means responsive to engine operating conditions for moving the fuel enrichment control lever to provide the changed A/F ratio.

  7. A Recipe for Ratio

    ERIC Educational Resources Information Center

    Moffett, Pamela

    2012-01-01

    Many learners still struggled to appreciate, and understand the difference between, the concepts of fractions and ratio. This is not just a UK phenomenon, which is demonstrated here by the use of a resource developed by the Wisconsin Centre for Education, in association with the Freudenthal Institute of the University of Utrecht, with a group of

  8. Area Ratios of Quadrilaterals.

    ERIC Educational Resources Information Center

    Anderson, David R.; Arcidiacono, Michael J.

    1989-01-01

    Shows that the ratio of the area of the quadrilateral formed by joining the kth points to the area of the original quadrilateral is constant whether it is convex or concave quadrilateral. Presents many geoboard or dot paper diagrams and geometrical expresssions. (YP)

  9. Cruise performance of an isolated 1.15 pressure ratio turbofan propulsion system simulator at Mach numbers from 0.6 to 0.85

    NASA Technical Reports Server (NTRS)

    Steffen, F. W.

    1974-01-01

    An isolated 1.15 pressure ratio turbofan engine simulator was tested at Mach numbers from 0.6 to 0.85. At Mach 0.75 the net propulsive force of the fan and nacelle (excluding core thrust) was 73 percent of the ideal fan net thrust. Internal losses amounted to 7 percent, and external drag amounted to 20 percent of the ideal fan net thrust. External pressure and friction drag were about equal. The propulsive efficiency with a 90 percent efficient fan would have been 63 percent. For the aerodynamic characteristics of the nacelle that was tested, increasing the fan pressure ratio to approximately 1.35 would have resulted in a maximum propulsive efficiency of 67 percent.

  10. The Effect of Ar/O2 Ratio on Electrochromic Response Time of Ni Oxides Grown Using an RF Sputtering System

    NASA Astrophysics Data System (ADS)

    Ahn, Kwang-Soon; Nah, Yoon-Chae; Yum, Jun-Ho; Sung, Yung-Eun

    2002-02-01

    The effect of Ar:O2 ratio on the electrochromic properties and the response time of NiO grown by RF sputtering were investigated by in situ transmittance measurements with continuous potential cycling and pulse potential cycling. The transmittance difference, coloration efficiency, memory effect, and cycling stability were all found to be independent of the Ar:O2 ratio. However, the transmittance of the as-deposited NiO as well as the response time were significantly affected. This may be attributed to the excess of oxygen occupied interstitial sites in the sputtered NiO that could result in the generation of Ni3+ ions and interference with proton intercalation/deintercalation.

  11. Automated airway evaluation system for multi-slice computed tomography using airway lumen diameter, airway wall thickness and broncho-arterial ratio

    NASA Astrophysics Data System (ADS)

    Odry, Benjamin L.; Kiraly, Atilla P.; Novak, Carol L.; Naidich, David P.; Lerallut, Jean-Francois

    2006-03-01

    Pulmonary diseases such as bronchiectasis, asthma, and emphysema are characterized by abnormalities in airway dimensions. Multi-slice computed tomography (MSCT) has become one of the primary means to depict these abnormalities, as the availability of high-resolution near-isotropic data makes it possible to evaluate airways at oblique angles to the scanner plane. However, currently, clinical evaluation of airways is typically limited to subjective visual inspection only: systematic evaluation of the airways to take advantage of high-resolution data has not proved practical without automation. We present an automated method to quantitatively evaluate airway lumen diameter, wall thickness and broncho-arterial ratios. In addition, our method provides 3D visualization of these values, graphically illustrating the location and extent of disease. Our algorithm begins by automatic airway segmentation to extract paths to the distal airways, and to create a map of airway diameters. Normally, airway diameters decrease as paths progress distally; failure to taper indicates abnormal dilatation. Our approach monitors airway lumen diameters along each airway path in order to detect abnormal profiles, allowing even subtle degrees of pathologic dilatation to be identified. Our method also systematically computes the broncho-arterial ratio at every terminal branch of the tree model, as a ratio above 1 indicates potentially abnormal bronchial dilatation. Finally, the airway wall thickness is computed at corresponding locations. These measurements are used to highlight abnormal branches for closer inspection, and can be summed to compute a quantitative global score for the entire airway tree, allowing reproducible longitudinal assessment of disease severity. Preliminary tests on patients diagnosed with bronchiectasis demonstrated rapid identification of lack of tapering, which also was confirmed by corresponding demonstration of elevated broncho-arterial ratios.

  12. Spectral ratio method for measuring emissivity

    USGS Publications Warehouse

    Watson, K.

    1992-01-01

    The spectral ratio method is based on the concept that although the spectral radiances are very sensitive to small changes in temperature the ratios are not. Only an approximate estimate of temperature is required thus, for example, we can determine the emissivity ratio to an accuracy of 1% with a temperature estimate that is only accurate to 12.5 K. Selecting the maximum value of the channel brightness temperatures is an unbiased estimate. Laboratory and field spectral data are easily converted into spectral ratio plots. The ratio method is limited by system signal:noise and spectral band-width. The images can appear quite noisy because ratios enhance high frequencies and may require spatial filtering. Atmospheric effects tend to rescale the ratios and require using an atmospheric model or a calibration site. ?? 1992.

  13. Weather-Corrected Performance Ratio

    SciTech Connect

    Dierauf, T.; Growitz, A.; Kurtz, S.; Cruz, J. L. B.; Riley, E.; Hansen, C.

    2013-04-01

    Photovoltaic (PV) system performance depends on both the quality of the system and the weather. One simple way to communicate the system performance is to use the performance ratio (PR): the ratio of the electricity generated to the electricity that would have been generated if the plant consistently converted sunlight to electricity at the level expected from the DC nameplate rating. The annual system yield for flat-plate PV systems is estimated by the product of the annual insolation in the plane of the array, the nameplate rating of the system, and the PR, which provides an attractive way to estimate expected annual system yield. Unfortunately, the PR is, again, a function of both the PV system efficiency and the weather. If the PR is measured during the winter or during the summer, substantially different values may be obtained, making this metric insufficient to use as the basis for a performance guarantee when precise confidence intervals are required. This technical report defines a way to modify the PR calculation to neutralize biases that may be introduced by variations in the weather, while still reporting a PR that reflects the annual PR at that site given the project design and the project weather file. This resulting weather-corrected PR gives more consistent results throughout the year, enabling its use as a metric for performance guarantees while still retaining the familiarity this metric brings to the industry and the value of its use in predicting actual annual system yield. A testing protocol is also presented to illustrate the use of this new metric with the intent of providing a reference starting point for contractual content.

  14. Bromine isotope ratio measurements in seawater by multi-collector inductively coupled plasma-mass spectrometry with a conventional sample introduction system.

    PubMed

    de Gois, Jefferson S; Vallelonga, Paul; Spolaor, Andrea; Devulder, Veerle; Borges, Daniel L G; Vanhaecke, Frank

    2016-01-01

    A simple and accurate methodology for Br isotope ratio measurements in seawater by multi-collector inductively coupled plasma-mass spectrometry (MC-ICP-MS) with pneumatic nebulization for sample introduction was developed. The Br(+) signals could be measured interference-free at high mass resolution. Memory effects for Br were counteracted using 5 mmol L(-1) of NH4OH in sample, standard, and wash solutions. The major cation load of seawater was removed via cation exchange chromatography using Dowex 50WX8 resin. Subsequent Br preconcentration was accomplished via evaporation of the sample solution at 90 °C, which did not induce Br losses or isotope fractionation. Mass discrimination was corrected for by external correction using a Cl-matched standard measured in a sample-standard bracketing approach, although Sr, Ge, and Se were also tested as potential internal standards for internal correction for mass discrimination. The δ(81)Br (versus standard mean ocean bromide (SMOB)) values thus obtained for the NaBr isotopic reference material NIST SRM 977 and for IRMM BCR-403 seawater certified reference material are in agreement with literature values. For NIST SRM 977, the (81)Br/(79)Br ratio (0.97291) was determined with a precision ≤0.08‰ relative standard deviation (RSD). Graphical Abstract A simple and accurate methodology for Br isotope ratio measurement in seawater by multi-collector inductively coupled plasma-mass spectrometry was developed. The cation load of seawater was removed using cation exchange chromatography. Spectral interference was avoided using high mass resolution. PMID:26123436

  15. Pyrolaser Operating System

    NASA Technical Reports Server (NTRS)

    Roberts, Floyd E., III

    1994-01-01

    Software provides for control and acquisition of data from optical pyrometer. There are six individual programs in PYROLASER package. Provides quick and easy way to set up, control, and program standard Pyrolaser. Temperature and emisivity measurements either collected as if Pyrolaser in manual operating mode or displayed on real-time strip charts and stored in standard spreadsheet format for posttest analysis. Shell supplied to allow macros, which are test-specific, added to system easily. Written using Labview software for use on Macintosh-series computers running System 6.0.3 or later, Sun Sparc-series computers running Open-Windows 3.0 or MIT's X Window System (X11R4 or X11R5), and IBM PC or compatible computers running Microsoft Windows 3.1 or later.

  16. High temperature measurement system devised for Claus reactors

    SciTech Connect

    Wadi, I. )

    1989-11-01

    High temperatures encountered in Claus sulfur recovery unit reaction furnaces can be measured accurately and reliably by using a special arrangement of two thermocouples and two optical pyrometers at two locations in the Claus reaction furnace. The measurement system was developed as a result of investigations and trials done on the Claus sulfur recovery unit at a Ruwais refinery. From those investigations, some general recommendations on thermo-couple types and installations for Claus reactor applications were determined. The author presents those recommendations, and the details on the special temperature measurement system considered to provide the best accuracy and reliability.

  17. Effect of particle aspect ratio in magnetorheology

    NASA Astrophysics Data System (ADS)

    Morillas, Jose R.; Carren-Gonzlez, Elizabeth; de Vicente, Juan

    2015-12-01

    We investigate the influence of the aspect ratio of the dispersed particles in magnetorheology. Two systems are studied: conventional magnetorheological fluids prepared by dispersion of nickel nanowires, and inverse ferrofluids prepared by dispersion of glass fibers in a ferrofluid. In both cases the apparent yield stress is found to increase with aspect ratio in contradiction to available models in the literature. Experimental observations demonstrate that the particle volume fraction within the aggregates initially increases with increasing the aspect ratio of the dispersed particles. When the aspect ratio is further raised, a gel-like percolating structure forms inhibiting the formation of elongated clusters in the field direction.

  18. Isotope ratio of Cl NQR spin-lattice relaxation times in 1D hydrogen-bonding system of tetramethylpyrazine-chloranilic acid at high temperatures

    NASA Astrophysics Data System (ADS)

    Asaji, Tetsuo

    2013-05-01

    The temperature dependences of spin-lattice relaxation time T 1 of 35Cl and 37Cl NQR were studied for the co-crystal of tetramethylpyrazine (TMP) with chloranilic acid (H2ca), TMP-H2ca, in which one-dimensional hydrogen bonding is formed by alternate arrangement of TMP and H2ca. The isotope ratio 37Cl T 1 / 35Cl T 1 was determined to be 1.0 0.1 above ca. 290 K where a steep decrease of spin-lattice relaxation time T 1 with increasing temperature was observed. In this temperature range it is suggested that the relaxation is originated from the slow fluctuation of electric field gradient (EFG). Beside EFG fluctuation due to the external-charge-density fluctuation, the small angle reorientation of the quantization axis triggered by a proton transfer motion between N...H-O and N-H...O hydrogen bonding states is proposed.

  19. Mass balance of pharmaceutical and personal care products in a pilot-scale single-sludge system: influence of T, SRT and recirculation ratio.

    PubMed

    Surez, Sonia; Reif, Rubn; Lema, Juan M; Omil, Francisco

    2012-09-01

    The influence of operation condition on the fate of 16 pharmaceutical and personal care products (PPCPs) in a single-sludge nitrifying/denitrifying pilot plant was assessed. Volatilisation, sorption and degradation were included in the mass balances to determine the most relevant removal mechanisms during PPCP treatment. Sludge retention time (SRT) was an important factor for the removal of compounds that significantly sorb onto sludge, as ethinylestradiol, whose removal increased 11% when working at SRT above 20 d. The internal recirculation ratio was significant for the removal of moderately biodegradable compounds, as citalopram. The positive effect of operating at warmer temperatures was particularly significant for two antibiotics, implying a 30% increase in their transformations. In the case of naproxen, an influence of sludge acclimation and concentration was observed, leading to removal efficiencies from 27% to 99%. Concerning removal mechanisms, most compounds were removed due to biotransformation, although for fragrances sorption and volatilisation played a role. PMID:22732303

  20. Central Nervous System Effects of the Second-Generation Antihistamines Marketed in Japan -Review of Inter-Drug Differences Using the Proportional Impairment Ratio (PIR)-

    PubMed Central

    Isomura, Tatsuya; Kono, Takeshi; Hindmarch, Ian; Kikuchi, Norimasa; Murakami, Aya; Inuzuka, Kyoko; Kawana, Seiji

    2014-01-01

    Background Second-generation antihistamines (AHs) have, in general, fewer sedative effects than the first-generation. However, important inter-drug differences remain in the degree of cognitive and/or psychomotor impairment. The extent to which a particular compound causes disruption can be conveniently compared, to all other AHs, using the Proportional Impairment Ratio (PIR). Although the PIR can differentiate the relative impairment caused by individual drugs, there is no indication of the reliability of the ratios obtained. Objective To calculate the PIRs –together with 95% confidence intervals (CIs), as an index of reliability– and compare AHs currently, or soon to be, available in Japan, with respect to their intrinsic capacity to cause impairment. Methods Results from studies of cetirizine, desloratadine, ebastine, fexofenadine, levocetirizine, loratadine, mequitazine, and olopatadine were included in the PIR calculations. All data utilised came from crossover studies in healthy volunteers which were randomised and placebo and positive-internal controlled. Existing databases from studies reporting the sedative effects of AHs on objective (speed, accuracy, memory) and subjective (feeling) psychometrics were augmented, via results from suitable studies published after the previous reviews. The null value for a PIR was one. Results A total of 45 studies were finally included for this review. Of the AHs assessed, fexofenadine, ebastine, and levocetirizine showed a PIR for objective tests of 0. However, only fexofenadine (PIR = 0.49) had an upper limit of the 95% CI of less than 1. Fexofenadine, levocetirizine, desloratadine, olopatadine, loratadine, and mequitazine all had a PIR for subjective ratings of 0, but the upper limits of the 95% CIs were all in excess of 1, although fexofenadine (PIR = 2.57) was the lowest. Conclusions The results show that there are differences between second-generation AHs in the extent of sedation produced. However, subjective ratings indicate that patients may not necessarily be aware of this. PMID:25501360

  1. Directional gear ratio transmissions

    NASA Technical Reports Server (NTRS)

    Lafever, A. E. (inventor)

    1984-01-01

    Epicyclic gear transmissions which transmit output at a gear ratio dependent only upon the input's direction are considered. A transmission housing envelops two epicyclic gear assemblies, and has shafts extending from it. One shaft is attached to a sun gear within the first epicyclic gear assembly. Planet gears are held symmetrically about the sun gear by a planet gear carrier and are in mesh with both the sun gear and a ring gear. Two unidirectional clutches restrict rotation of the first planet gear carrier and ring gear to one direction. A connecting shaft drives a second sun gear at the same speed and direction as the first planet gear carrier while a connecting portion drives a second planet gear carrier at the same speed and direction as the first ring gear. The transmission's output is then transmitted by the second ring gear to the second shaft. Input is transmitted at a higher gear ratio and lower speed for all inputs in the first direction than in the opposite direction.

  2. Airborne ultraviolet imaging system for oil slick surveillance: oil-seawater contrast, imaging concept, signal-to-noise ratio, optical design, and optomechanical model.

    PubMed

    Shi, Zhenhua; Yu, Lei; Cao, Diansheng; Wu, Qingwen; Yu, Xiangyang; Lin, Guanyu

    2015-09-01

    The airborne ultraviolet imaging system, which assesses oil slick areas better than visible and infrared optical systems, was designed to monitor and track oil slicks in coastal regions. A model was built to achieve the upwelling radiance distribution of oil-covered sea and clean seawater, based on the radiance transfer software. With this model, the oil-seawater contrast, which affects the detection of oil-covered coastal areas, was obtained. The oil-seawater contrast, fundamental imaging concept, analog calculation of SNR, optical design, and optomechanical configuration of the airborne ultraviolet imaging system are illustrated in this paper. The study of an airborne ultraviolet imaging system with F-number 3.4 and a 40° field of view (FOV) in near ultraviolet channel (0.32-0.38 μm) was illustrated and better imaging quality was achieved. The ground sample distance (GSD) is from 0.35 to 0.7 m with flight height ranges from 0.5 to 1 km. Comparisons of detailed characteristics of the airborne ultraviolet imaging system with the corresponding characteristics of previous ultraviolet systems were tabulated, and these comparisons showed that this system can achieve a wide FOV and a relative high SNR. A virtual mechanical prototype and tolerances analysis are illustrated in this paper to verify the performance of fabrication and assembly of the ultraviolet system. PMID:26368888

  3. Calcium-to-Argon and Nickel-to-Argon Abundance Ratios as Tracers of the Source Region of Postflare Loop System Material

    NASA Astrophysics Data System (ADS)

    Widing, K. G.; Feldman, U.

    2008-03-01

    Intensities of abundance diagnostic lines of Ca XV, Ca XVI, Ni XVII, Ar XIII, and Ar XV have been derived for a classic flare loop system observed during the Skylab mission. These have been used to test for photospheric or coronal origin of the flare loop material. The resulting FIP-bias factors are between 1.7 and 4.6 with a majority of the values around 4.5 indicating a source with material modified by the FIP effect. The loop system bias factors are similar to those observed in a sample of Skylab prominences, suggesting that the disrupted mass of the preflare embedded filament provided the loop system material.

  4. Peak power ratio generator

    DOEpatents

    Moyer, Robert D. (Albuquerque, NM)

    1985-01-01

    A peak power ratio generator is described for measuring, in combination with a conventional power meter, the peak power level of extremely narrow pulses in the gigahertz radio frequency bands. The present invention in a preferred embodiment utilizes a tunnel diode and a back diode combination in a detector circuit as the only high speed elements. The high speed tunnel diode provides a bistable signal and serves as a memory device of the input pulses for the remaining, slower components. A hybrid digital and analog loop maintains the peak power level of a reference channel at a known amount. Thus, by measuring the average power levels of the reference signal and the source signal, the peak power level of the source signal can be determined.

  5. Low speed test of a high-bypass-ratio propulsion system with an asymmetric inlet designed for a tilt-nacelle V/STOL airplane

    NASA Technical Reports Server (NTRS)

    Syberg, J.

    1978-01-01

    A large scale model of a lift/cruise fan inlet designed for a tilt nacelle V/STOL airplane was tested with a high bypass ratio turbofan. Testing was conducted at low freestream velocities with inlet angles of attack ranging from 0 deg to 120 deg. The operating limits for the nacelle were found to be related to inlet boundary layer separation. Small separations originating in the inlet diffuser cause little or no performance degradation. However, at sufficiently severe freestream conditions the separation changes abruptly to a lip separation. This change is associated with a significant reduction in nacelle net thrust as well as a sharp increase in fan blade vibratory stresses. Consequently, the onset of lip separation is regarded as the nacelle operating limit. The test verified that the asymmetric inlet design will provide high performance and stable operation at the design forward speed and angle of attack conditions. At some of these, however, operation near the lower end of the design inlet airflow range is not feasible due to the occurrence of lip separation.

  6. From the Companion Mass Ratio Distribution to the Planetary Mass Function: Using Multiple Systems to Constrain Models of Star and Planet Formation

    NASA Astrophysics Data System (ADS)

    Reggiani, Maddalena; Meyer, Michael R.

    We present new results regarding the companion mass ratio distribution (CMRD) of stars, and sub-stellar objects. Considering the new survey of multiples for solar type field stars (Raghavan et al. ApJS 190:1, 2010) and M dwarfs (Janson et al. ApJ 754(1):26, 2012), we test the universality of the CMRD derived in Reggiani and Meyer (ApJ 738:60, 2011). Whereas we do not find significant differences in the CMRD for M dwarfs compared to previous results, the solar type CMRD appears to inconsistent with the previously derived CMRD from Reggiani and Meyer (ApJ 738:60, 2011). Despite the fact that this survey spans a wider range of angular separations than the previously studied samples, there is no evidence for variations in the CMRD as a function of orbital separation. Assuming that we can extrapolate both the stellar CMRD into the BD regime and the radial velocity planetary Companion Mass Function (Cumming et al. PASP 120:531, 2008) to larger separations, we can run MC simulations to test in which mass range we expect the planet population to become more important than BDs as companions to stars. This tool can be useful to predict the outcome of future surveys for very low mass companions or to analyze already existing datasets.

  7. A Mission-Adaptive Variable Camber Flap Control System to Optimize High Lift and Cruise Lift-to-Drag Ratios of Future N+3 Transport Aircraft

    NASA Technical Reports Server (NTRS)

    Urnes, James, Sr.; Nguyen, Nhan; Ippolito, Corey; Totah, Joseph; Trinh, Khanh; Ting, Eric

    2013-01-01

    Boeing and NASA are conducting a joint study program to design a wing flap system that will provide mission-adaptive lift and drag performance for future transport aircraft having light-weight, flexible wings. This Variable Camber Continuous Trailing Edge Flap (VCCTEF) system offers a lighter-weight lift control system having two performance objectives: (1) an efficient high lift capability for take-off and landing, and (2) reduction in cruise drag through control of the twist shape of the flexible wing. This control system during cruise will command varying flap settings along the span of the wing in order to establish an optimum wing twist for the current gross weight and cruise flight condition, and continue to change the wing twist as the aircraft changes gross weight and cruise conditions for each mission segment. Design weight of the flap control system is being minimized through use of light-weight shape memory alloy (SMA) actuation augmented with electric actuators. The VCCTEF program is developing better lift and drag performance of flexible wing transports with the further benefits of lighter-weight actuation and less drag using the variable camber shape of the flap.

  8. Lorentz ratio of quantum plasmas

    SciTech Connect

    Khalfaoui, A.; Bennaceur, D. )

    1994-06-01

    A quantum collective approach is developed to investigate linear transport properties of a system of highly degenerate weakly coupled electrons and strongly coupled semiclassical ions. The basic formalism rests upon suitable extention of the Boltzmann--Bloch quantum transport equation. The model considers electron--ion (e--i) and electron--electron (e--e) collisions in a unified scheme of both long- and short-range Coulomb interactions. The e--e collisions contribute to the thermal conductivity calculation in the low coupling regime. Even though they can be insignificant for strongly coupled systems, the extensively used Lorentz gas approximation cannot be justified for plasmas of astrophysical interests. It is shown that the Lorentz ratio of high-density plasma may exhibit substantial negative deviation from the ideal Sommerfeld value, due to some nonidealities, such as e--e interaction and quantum effects. Results are presented under analytical and compact forms allowing numerical applications, as well as comparisons with existing theories.

  9. High-Ratio Gear Train

    NASA Technical Reports Server (NTRS)

    Lefever, A. E.

    1982-01-01

    Proposed arrangement of two connected planetary differentials results in gear ratio many times that obtainable in conventional series gear assembly of comparable size. Ratios of several thousand would present no special problems. Selection of many different ratios is available with substantially similar gear diameters. Very high gear ratios would be obtained from small mechanism.

  10. Correlation between the signal-to-noise ratio improvement factor (KSNR) and clinical image quality for chest imaging with a computed radiography system

    NASA Astrophysics Data System (ADS)

    Moore, C. S.; Wood, T. J.; Saunderson, J. R.; Beavis, A. W.

    2015-12-01

    This work assessed the appropriateness of the signal-to-noise ratio improvement factor (KSNR) as a metric for the optimisation of computed radiography (CR) of the chest. The results of a previous study in which four experienced image evaluators graded computer simulated chest images using a visual grading analysis scoring (VGAS) scheme to quantify the benefit of using an anti-scatter grid were used for the clinical image quality measurement (number of simulated patients  =  80). The KSNR was used to calculate the improvement in physical image quality measured in a physical chest phantom. KSNR correlation with VGAS was assessed as a function of chest region (lung, spine and diaphragm/retrodiaphragm), and as a function of x-ray tube voltage in a given chest region. The correlation of the latter was determined by the Pearson correlation coefficient. VGAS and KSNR image quality metrics demonstrated no correlation in the lung region but did show correlation in the spine and diaphragm/retrodiaphragmatic regions. However, there was no correlation as a function of tube voltage in any region; a Pearson correlation coefficient (R) of  ‑0.93 (p  =  0.015) was found for lung, a coefficient (R) of  ‑0.95 (p  =  0.46) was found for spine, and a coefficient (R) of  ‑0.85 (p  =  0.015) was found for diaphragm. All demonstrate strong negative correlations indicating conflicting results, i.e. KSNR increases with tube voltage but VGAS decreases. Medical physicists should use the KSNR metric with caution when assessing any potential improvement in clinical chest image quality when introducing an anti-scatter grid for CR imaging, especially in the lung region. This metric may also be a limited descriptor of clinical chest image quality as a function of tube voltage when a grid is used routinely.

  11. Prognostic Significance of Systemic Inflammation-Based Lymphocyte- Monocyte Ratio in Patients with Lung Cancer: Based on a Large Cohort Study

    PubMed Central

    Hu, Pingping; Shen, Hongchang; Wang, Guanghui; Zhang, Ping; Liu, Qi; Du, Jiajun

    2014-01-01

    Increasing evidence indicates cancer-related inflammatory biomarkers show great promise for predicting the outcome of cancer patients. The lymphocyte- monocyte ratio (LMR) was demonstrated to be independent prognostic factor mainly in hematologic tumor. The aim of the present study was to investigate the prognostic value of LMR in operable lung cancer. We retrospectively enrolled a large cohort of patients with primary lung cancer who underwent complete resection at our institution from 2006 to 2011. Inflammatory biomarkers including lymphocyte count and monocyte count were collected from routinely performed preoperative blood tests and the LMR was calculated. Survival analyses were calculated for overall survival (OS) and disease-free survival (DFS). A total of 1453 patients were enrolled in the study. The LMR was significantly associated with OS and DFS in multivariate analyses of the whole cohort (HR?=?1.522, 95% CI: 1.2751.816 for OS, and HR?=?1.338, 95% CI: 1.1521.556 for DFS). Univariate subgroup analyses disclosed that the prognostic value was limited to patients with non-small-cell lung cancer (NSCLC) (HR: 1.824, 95% CI: 1.5202.190), in contrast to patients with small cell lung cancer (HR: 1.718, 95% CI: 0.9463.122). Multivariate analyses demonstrated that LMR was still an independent prognostic factor in NSCLC. LMR can be considered as a useful independent prognostic marker in patients with NSCLC after complete resection. This will provide a reliable and convenient biomarker to stratify high risk of death in patients with operable NSCLC. PMID:25275631

  12. FORMATION AND EVOLUTION OF THE DISK SYSTEM OF THE MILKY WAY: [{alpha}/Fe] RATIOS AND KINEMATICS OF THE SEGUE G-DWARF SAMPLE

    SciTech Connect

    Lee, Young Sun; Beers, Timothy C.; An, Deokkeun; Ivezic, Zeljko; Just, Andreas; Rockosi, Constance M.; Johnson, Jennifer A.; Bird, Jonathan; Schoenrich, Ralph; Yanny, Brian; Rocha-Pinto, Helio J. E-mail: beers@pa.msu.edu

    2011-09-10

    We employ measurements of the [{alpha}/Fe] ratio derived from low-resolution (R {approx} 2000) spectra of 17,277 G-type dwarfs from the SEGUE survey to separate them into likely thin- and thick-disk subsamples. Both subsamples exhibit strong gradients of orbital rotational velocity with metallicity, of opposite signs, -20 to -30 km s{sup -1} dex{sup -1} for the thin-disk and +40 to +50 km s{sup -1} dex{sup -1} for the thick-disk population. The rotational velocity is uncorrelated with Galactocentric distance for the thin-disk subsample and exhibits a small trend for the thick-disk subsample. The rotational velocity decreases with distance from the plane for both disk components, with similar slopes (-9.0 {+-} 1.0 km s{sup -1} kpc{sup -1}). Thick-disk stars exhibit a strong trend of orbital eccentricity with metallicity (about -0.2 dex{sup -1}), while the eccentricity does not change with metallicity for the thin-disk subsample. The eccentricity is almost independent of Galactocentric radius for the thin-disk population, while a marginal gradient of the eccentricity with radius exists for the thick-disk population. Both subsamples possess similar positive gradients of eccentricity with distance from the Galactic plane. The shapes of the eccentricity distributions for the thin- and thick-disk populations are independent of distance from the plane, and include no significant numbers of stars with eccentricity above 0.6. Among several contemporary models of disk evolution that we consider, radial migration appears to have played an important role in the evolution of the thin-disk population, but possibly less so for the thick disk, relative to the gas-rich merger or disk heating scenarios. We emphasize that more physically realistic models and simulations need to be constructed in order to carry out the detailed quantitative comparisons that our new data enable.

  13. Correlation between the signal-to-noise ratio improvement factor (KSNR) and clinical image quality for chest imaging with a computed radiography system.

    PubMed

    Moore, C S; Wood, T J; Saunderson, J R; Beavis, A W

    2015-12-01

    This work assessed the appropriateness of the signal-to-noise ratio improvement factor (KSNR) as a metric for the optimisation of computed radiography (CR) of the chest. The results of a previous study in which four experienced image evaluators graded computer simulated chest images using a visual grading analysis scoring (VGAS) scheme to quantify the benefit of using an anti-scatter grid were used for the clinical image quality measurement (number of simulated patients??=??80). The KSNR was used to calculate the improvement in physical image quality measured in a physical chest phantom. KSNR correlation with VGAS was assessed as a function of chest region (lung, spine and diaphragm/retrodiaphragm), and as a function of x-ray tube voltage in a given chest region. The correlation of the latter was determined by the Pearson correlation coefficient. VGAS and KSNR image quality metrics demonstrated no correlation in the lung region but did show correlation in the spine and diaphragm/retrodiaphragmatic regions. However, there was no correlation as a function of tube voltage in any region; a Pearson correlation coefficient (R) of??-0.93 (p??=??0.015) was found for lung, a coefficient (R) of??-0.95 (p??=??0.46) was found for spine, and a coefficient (R) of??-0.85 (p??=??0.015) was found for diaphragm. All demonstrate strong negative correlations indicating conflicting results, i.e. KSNR increases with tube voltage but VGAS decreases. Medical physicists should use the KSNR metric with caution when assessing any potential improvement in clinical chest image quality when introducing an anti-scatter grid for CR imaging, especially in the lung region. This metric may also be a limited descriptor of clinical chest image quality as a function of tube voltage when a grid is used routinely. PMID:26540441

  14. Volume ratios between the thermophilic and the mesophilic digesters of a temperature-phased anaerobic digestion system affect their performance and microbial communities.

    PubMed

    Lv, Wen; Zhang, Wenfei; Yu, Zhongtang

    2016-01-25

    An experimental temperature-phased anaerobic digestion (TPAD) system, with the thermophilic digester operated at neutral pH and with a balanced acidogenesis and methanogenesis (referred to as NT-TPAD), was evaluated with respect to the microbial communities and population dynamics of methanogens when digesting dairy cattle manure at 15-day overall system hydraulic retention time (HRT). When fed a manure slurry of 10% total solid (TS), similar system performance, 36-38% volatile solid (VS) removal and 0.21-0.22 L methane g(-1) VS fed, was achieved between a 5-day and 7.5-day HRT for the thermophilic digester. However, the thermophilic digester achieved a greater volumetric biogas yield when operated at a 5-day RT than at a 7.5-day HRT (6.3 vs. 4.7 L/L/d), while the mesophilic digester had a stable volumetric biogas yield (about 1.0 L/L/d). Each of the digesters harbored distinct yet dynamic microbial populations, and some of the methanogens were significantly correlated with methane productions. Methanosarcina and Methanosaeta were the most important methanogenic genera in the thermophilic and the mesophilic digesters, respectively. The microbiological findings may help understand the metabolism that underpins the anaerobic processes within each of the two digesters of TPAD systems when fed dairy manure. PMID:26232524

  15. Tuning the Formations of Metal-Organic Frameworks by Modification of Ratio of Reactant, Acidity of Reaction System, and Use of a Secondary Ligand

    SciTech Connect

    Gao, Q; Xie, YB; Li, JR; Yuan, DQ; Yakovenko, AA; Sun, JH; Zhou, HC

    2012-01-01

    Four porous coordination networks (PCNs), {[Zn3O(H2O)(3)(adc)(3)]center dot 2(C2H6NH2)center dot 2(DMF)center dot 3(H2O)}(n) (PCN-131), Zn-2(DMA)(2)(adc)(2)]center dot 2(DMA)}(n) (PCN-132), {[Zn3O(DMF)(adc)(3)(4,4'-bpy)]center dot 2(C2H6NH2)center dot S}(n) (PCN-131'), and {[Zn(adc)(4,4'-bpy)(0.5)]center dot S}(n) (PCN-132'), have been synthesized by the assembly of anthrancene-9,10-dicarboxylic acid (H(2)adc) with Zn(II) under different reaction conditions, including modifications of reactant ratio, acidity variations, and the use of a secondary ligand. Single-crystal X-ray diffraction studies reveal that PCN-131, obtained from the dimethylformamide (DMF) solution under acid condition, has a three-dimentional (3D) framework structure with one-dimensional (1D) honeycomb channels. PCN-132 isolated from dimethylacetamide (DMA) solution without adding acid in synthesis is a two-dimensional (2D) layer compound. By employing 4,4'-bipyridyl (4,4'-bpy) as a secondary ligand, PCN-131' and PCN-132' were synchronously synthesized as a mixture outcome with more PCN-131' than PCN-132'. In PCN-131', 4,4'-bpy acting as a secondary ligand is arranged inside the honeycomb channel of the 3D PCN-131, resulting in an effective improvement of thermal stability of the network, while in PCN-132', 4,4'-bpy ligands link 2D layers of PCN-132 to form a pillared-layer 3D framework Gas adsorption has been performed for selected materials. The results show that the framework of PCN-131 is thermally unstable after removing the solvent molecules coordinated to their metal sites. While PCN-131' is stable for gas uptake, with an evaluated Langmuir surface area of 199.04 m(2) g(-1), it shows a selective adsorption of CO2 over CH4.

  16. Energy Profit Ratio Compared

    SciTech Connect

    Amano, Osamu

    2007-07-01

    We need more oil energy to take out oil under the ground. Limit resources make us consider other candidates of energy source instead of oil. Electricity shall be the main role more and more like electric vehicles and air conditioners so we should consider electricity generation ways. When we consider what kind of electric power generation is the best or suitable, we should not only power generation plant but whole process from mining to power generation. It is good way to use EPR, Energy Profit Ratio, to analysis which type is more efficient and which part is to do research and development when you see the input breakdown analysis. Electricity by the light water nuclear power plant, the hydrogen power plant and the geothermal power plant are better candidates from EPR analysis. Forecasting the world primly energy supply in 2050, it is said that the demand will be double of the demand in 2000 and the supply will not be able to satisfy the demand in 2050. We should save 30% of the demand and increase nuclear power plants 3.5 times more and recyclable energy like hydropower plants 3 times more. When the nuclear power plants are 3.5 times more then uranium peak will come and we will need breed uranium. I will analysis the EPR of FBR. Conclusion: A) the EPR of NPS in Japan is 17.4 and it is the best of all. B) Many countries will introduce new nuclear power plants rapidly may be 3.5 times in 2050. C) Uranium peak will happen around 2050. (author)

  17. High-response on-line gas analysis system for hydrogen-reaction combustion products

    NASA Technical Reports Server (NTRS)

    Metzler, A. J.; Gaugler, R. E.

    1974-01-01

    The results of testing an on-line quadrupole gas analyzer system are reported. Gas samples were drawn from the exhaust of a hydrogen-oxygen-nitrogen rocket which simulated the flow composition and dynamics at the combustor exit of a supersonic combustion ramjet engine. System response time of less than 50 milliseconds was demonstrated, with analytical accuracy estimated to be + or - 5 percent. For more complex chemical systems with interfering atom patterns, analysis would be more difficult. A cooled-gas pyrometer probe was evaluated as a total temperature indicator and as the primary mass flow measuring element for the total sample flow rate.

  18. Correlation of infrared reflectance ratios at 2.3 microns/1.6 micron and 1.1 micron/1.6 micron with delta O-18 values delineating fossil hydrothermal systems in the Idaho batholith

    NASA Technical Reports Server (NTRS)

    Gillespie, A. R.; Criss, R. E.

    1983-01-01

    Reflectance ratios from laboratory spectra and airborne multispectral images are found to be strongly correlated with delta O-18 values of granite rocks in the Idaho batholith. The correlation is largely a result of interactions between hot water and rock, which lowered the delta O-18 values of the rocks and produced secondary hydrous material. Maps of the ratio of reflectivities at 2.3 and 1.6 microns should delineate fossil hydrothermal systems and provide estimates of alteration intensity. However, hydrous minerals produced during deuteric alteration or weathering cannot be unambiguously distinguished in remotely sensed images from the products of propylitic alteration without the use of narrow-band scanners. The reflectivity at 1.6 micron is strongly correlated with rock density and may be useful in distinguishing rock types in granitic terranes.

  19. Using Cl/Br ratios and other indicators to assess potential impacts on groundwater quality from septic systems: A review and examples from principal aquifers in the United States

    NASA Astrophysics Data System (ADS)

    Katz, Brian G.; Eberts, Sandra M.; Kauffman, Leon J.

    2011-02-01

    SummaryA detailed review was made of chemical indicators used to identify impacts from septic tanks on groundwater quality. Potential impacts from septic tank leachate on groundwater quality were assessed using the mass ratio of chloride-bromide (Cl/Br), concentrations of selected chemical constituents, and ancillary information (land use, census data, well depth, soil characteristics) for wells in principal aquifers of the United States. Chemical data were evaluated from 1848 domestic wells in 19 aquifers, 121 public-supply wells in 6 aquifers, and associated monitoring wells in four aquifers and their overlying hydrogeologic units. Based on previously reported Cl/Br ratios, statistical comparisons between targeted wells (where Cl/Br ratios range from 400 to 1100 and Cl concentrations range from 20 to 100 mg/L) and non-targeted wells indicated that shallow targeted monitoring and domestic wells (<20 m depth below land surface) had a significantly ( p < 0.05) higher median percentage of houses with septic tanks (1990 census data) than non-targeted wells. Higher ( p = 0.08) median nitrate-N concentration (3.1 mg/L) in oxic (dissolved oxygen concentrations >0.5 mg/L) shallow groundwater from target domestic wells, relative to non-target wells (1.5 mg/L), corresponded to significantly higher potassium, boron, chloride, dissolved organic carbon, and sulfate concentrations, which may also indicate the influence of septic-tank effluent. Impacts on groundwater quality from septic systems were most evident for the Eastern Glacial Deposits aquifer and the Northern High Plains aquifer that were associated with the number of housing units using septic tanks, high permeability of overlying sediments, mostly oxic conditions, and shallow wells. Overall, little or no influence from septic systems were found for water samples from the deeper public-supply wells. The Cl/Br ratio is a useful first-level screening tool for assessing possible septic tank influence in water from shallow wells (<20 m) with the range of 400-1100. The use of this ratio would be enhanced with information on other chloride sources, temporal variability of chloride and bromide concentrations in shallow groundwater, knowledge of septic-system age and maintenance, and the use of multiple tracers (combination of additional chemical and microbiological indicators).

  20. Using Cl/Br ratios and other indicators to assess potential impacts on groundwater quality from septic systems: A review and examples from principal aquifers in the United States

    USGS Publications Warehouse

    Katz, B.G.; Eberts, S.M.; Kauffman, L.J.

    2011-01-01

    A detailed review was made of chemical indicators used to identify impacts from septic tanks on groundwater quality. Potential impacts from septic tank leachate on groundwater quality were assessed using the mass ratio of chloride-bromide (Cl/Br), concentrations of selected chemical constituents, and ancillary information (land use, census data, well depth, soil characteristics) for wells in principal aquifers of the United States. Chemical data were evaluated from 1848 domestic wells in 19 aquifers, 121 public-supply wells in 6 aquifers, and associated monitoring wells in four aquifers and their overlying hydrogeologic units. Based on previously reported Cl/Br ratios, statistical comparisons between targeted wells (where Cl/Br ratios range from 400 to 1100 and Cl concentrations range from 20 to 100 mg/L) and non-targeted wells indicated that shallow targeted monitoring and domestic wells (0.5. mg/L) shallow groundwater from target domestic wells, relative to non-target wells (1.5. mg/L), corresponded to significantly higher potassium, boron, chloride, dissolved organic carbon, and sulfate concentrations, which may also indicate the influence of septic-tank effluent. Impacts on groundwater quality from septic systems were most evident for the Eastern Glacial Deposits aquifer and the Northern High Plains aquifer that were associated with the number of housing units using septic tanks, high permeability of overlying sediments, mostly oxic conditions, and shallow wells. Overall, little or no influence from septic systems were found for water samples from the deeper public-supply wells.The Cl/Br ratio is a useful first-level screening tool for assessing possible septic tank influence in water from shallow wells (<20 m) with the range of 400-1100. The use of this ratio would be enhanced with information on other chloride sources, temporal variability of chloride and bromide concentrations in shallow groundwater, knowledge of septic-system age and maintenance, and the use of multiple tracers (combination of additional chemical and microbiological indicators). ?? 2010.

  1. Note: An advanced in situ diagnostic system for characterization of electric propulsion thrusters and ion beam sources.

    PubMed

    Bundesmann, C; Tartz, M; Scholze, F; Leiter, H J; Scortecci, F; Gnizdor, R Y; Neumann, H

    2010-04-01

    We present an advanced diagnostic system for in situ characterization of electric propulsion thrusters and ion beam sources. The system uses a high-precision five-axis positioning system with a modular setup and the following diagnostic tools: a telemicroscopy head for optical imaging, a triangular laser head for surface profile scanning, a pyrometer for temperature scanning, a Faraday probe for current density mapping, and an energy-selective mass spectrometer for beam characterization (energy and mass distribution, composition). The capabilities of our diagnostic system are demonstrated with a Hall effect thruster SPT-100D EM1. PMID:20441379

  2. Controlling Gas-Flow Mass Ratios

    NASA Technical Reports Server (NTRS)

    Morris, Brian G.

    1990-01-01

    Proposed system automatically controls proportions of gases flowing in supply lines. Conceived for control of oxidizer-to-fuel ratio in new gaseous-propellant rocket engines. Gas-flow control system measures temperatures and pressures at various points. From data, calculates control voltages for electronic pressure regulators for oxygen and hydrogen. System includes commercially available components. Applicable to control of mass ratios in such gaseous industrial processes as chemical-vapor depostion of semiconductor materials and in automotive engines operating on compressed natural gas.

  3. Competing antiferromagnetism and local magnetic order in the bulk ceramic PZT-PFW multiferroic system: searching for the most promising ratio between PZT and PFW

    NASA Astrophysics Data System (ADS)

    Pajić, D.; Jagodič, M.; Jagličić, Z.; Holc, J.; Kosec, M.; Trontelj, Z.

    2013-11-01

    Bulk ceramic compounds of formula xPZT + (1 - x)PFW, where PZT = Pb(Zr0.575Ti0.425)O3 and PFW = Pb(Fe2/3W1/3)O3, for x = 0.15 0.20; 0.25; 0.37; 0.50; 0.60; 0.65; 0.70 and 0.80, were synthesized. In these single phase perovskites a change from rhombohedral to cubic structure is observed as the proportion of PFW increases. Magnetic investigations including zero-field cooled and field-cooled magnetization versus temperature measurements, magnetic hysteresis loops measurement and ac susceptibility measurements were performed. At high temperatures a clear antiferromagnetic (AFM)-like transition was observed for high PFW concentrations. The low temperature behaviour indicated spin freezing and thermal activation of magnetic moments and measurements confirmed the existence of a barrier maximum for x = 0.37. Competition between the long-range AFM order and short-range magnetic ordering of small nano-sized regions with finite magnetic moments was observed in the studied system.

  4. The effect of SiO?/Al?O? ratio on the structure and microstructure of the glazes from SiO?-Al?O?-CaO-MgO-Na?O-K?O system.

    PubMed

    Partyka, Janusz; Sitarz, Maciej; Le?niak, Magdalena; Gasek, Katarzyna; Jele?, Piotr

    2015-01-01

    Ceramic glazes are commonly used to covering of the facing surface of ceramics ware. A well-chosen oxide composition and firing conditions of glazes causes significant improvement of technical parameters of ceramic products. Modern glazes are classified as glass-ceramic composites with different crystalline phases arising during firing. The presence of crystals in the glass matrix is influenced by many factors, especially by oxides molar composition. A crucial role is played by the molar ratio of SiO?/Al?O?. In this work the six composition of glazes from SiO?-Al?O?-CaO-MgO-Na?O-K?O system were examined. The only variable is the ratio of the silicon oxideto alumina at a constant content of other components: MgO, CaO, K?O, Na?O, ZnO. In order to determine the real phase composition of the obtained glazes research on fluorescence spectrometer (XRF) were done. For structural studies X-ray diffraction (XRD) and spectroscopic in the middle infrared (MIR) were performed. In order to determine the state of the surface (microstructure) research on the scanning electron microscope (SEM) with EDX. The research allowed to determine the influence of SiO?/Al?O? ratio on the structure and phase composition of glazes and the nature, and type of formed crystalline phases. PMID:25049171

  5. Spatial and temporal infaunal dynamics of the Blanes submarine canyon-slope system (NW Mediterranean); changes in nematode standing stocks, feeding types and gender-life stage ratios

    NASA Astrophysics Data System (ADS)

    Ingels, Jeroen; Vanreusel, Ann; Romano, Chiara; Coenjaerts, Johan; Mar Flexas, M.; Ziga, Diana; Martin, Daniel

    2013-11-01

    Despite recent advances in the knowledge of submarine canyons ecosystems, our understanding of the faunal patterns and processes in these environments is still marginal. In this study, meiobenthic nematode communities (from 300 m to 1600 m depth) obtained in November 2003 and May 2004 at eight stations inside and outside Blanes submarine canyon were analysed for nematode standing stocks (SSs), feeding types and gender-life stage distributions. Environmental data were obtained by sediment traps and current meters, attached to moorings (April 2003-May 2004), and sediments samples analysed for biogeochemistry and grain size (May 2004). In November 2003, nematode SSs decreased with increasing depth (367.2 individuals and 7.31 ?g C per 10 cm2 at 388 m water depth to 7.7 individuals and 0.18 ?g C per 10 cm2 at 1677 m water depth), showing a significant negative relation (abundance: R2 = 0.620, p = 0.020; biomass: R2 = 0.512, p = 0.046). This was not the case in May 2004 (283.5 individuals and 3.53 ?g C per 10 cm2 at 388 m water depth to 490.8 individuals and 4.93 ?g C per 10 cm2 at 1677 m water depth; abundance: R2 = 0.003, p = 0.902; biomass: R2 = 0.052, p = 0.587), suggesting a temporal effect that overrides the traditional decrease of SSs with increasing water depth. Both water depth and sampling time played a significant role in explaining nematode SSs, but with differences between stations. No overall differences were observed between canyon and open slope stations. Nematode standing stock (SS) patterns can be explained by taking into account the interplay of phytodetrital input and disturbance events, with station differences such as topography playing an important role. Individual nematode size decreased from November 2003 to May 2004 and was explained by a food-induced genera shift and/or a food-induced transition from a latent to a reproductive nematode community. Our results suggest that size patterns in nematode communities are not solely governed by trophic conditions over longer periods of time in relatively food-rich environments such as canyons. We hypothesize that food pulses in a dynamic and topographical heterogeneous environment such as canyons regulate nematode size distributions, rather than long-term food availability. Feeding type distributions in the Blanes Canyon did not clearly resemble those from other canyon systems, apart from the spring assemblage at one station in the head of the canyon.

  6. Substrate temperature measurement using a commercial band-edge detection system

    NASA Astrophysics Data System (ADS)

    Farrer, I.; Harris, J. J.; Thomson, R.; Barlett, D.; Taylor, C. A.; Ritchie, D. A.

    2007-04-01

    We report on the use of a commercially available band-edge detection system for substrate temperature monitoring of gallium arsenide substrates. The extension of the technique to the cases where strong absorption by either the substrate or substrate holder might normally preclude the use of such systems due to poor signal levels is discussed. For indium-mounted wafers, a background subtraction/removal is applied which allows unambiguous determination of the band edge across the full temperature range. An alternative method of operation of the instrument as a highly configurable pyrometer allows measurements to be made on highly conducting p-type substrates where free carrier absorption swamps the band edge.

  7. High pressure ratio turbocharger

    SciTech Connect

    Woollenweber, W.E.

    1991-06-25

    This patent describes a turbocharger system for an internal combustion engine. It comprises means forming a turbine adapted to be driven by exhaust gas from an internal combustion engine comprising: a turbine wheel having a central core and outwardly extending vanes, the turbine wheel being rotatable about a central axis; a meridionally divided volute for exhaust gas surrounding the turbine wheel, the meridionally divided volute including a divider wall defining first and second volute passageways with openings at the turbine wheel; means forming a high-pressure compressor driven by the turbine means, the high-pressure compressor comprising: rotating compressor blades, the compressor blades adapted to be driven in rotation about the central axis by the turbine means to deliver a flow of air at high pressures for an internal combustion engine, and blades being moveable about longitudinal axes generally transverse to the central axis to impart positive or negative pre-whirl motion to the air leaving the stator blades prior to entering the rotating blades of the compressor stage; closure means for providing a flow of engine exhaust gas from one of the first and second volute passageways into the turbine wheel; and a control means for operating the closure means and the stator blades in synchronization.

  8. Lidar ratio and depolarization ratio for cirrus clouds.

    PubMed

    Chen, Wei-Nai; Chiang, Chih-Wei; Nee, Jan-Bai

    2002-10-20

    We report on studies of the lidar and the depolarization ratios for cirrus clouds. The optical depth and effective lidar ratio are derived from the transmission of clouds, which is determined by comparing the backscattering signals at the cloud base and cloud top. The lidar signals were fitted to a background atmospheric density profile outside the cloud region to warrant the linear response of the return signals with the scattering media. An average lidar ratio, 29 +/- 12 sr, has been found for all clouds measured in 1999 and 2000. The height and temperature dependences ofthe lidar ratio, the optical depth, and the depolarization ratio were investigated and compared with results of LITE and PROBE. Cirrus clouds detected near the tropopause are usually optically thin and mostly subvisual. Clouds with the largest optical depths were found near 12 km with a temperature of approximately -55 degrees C. The multiple-scattering effect is considered for clouds with high optical depths, and this effect lowers the lidar ratios compared with a single-scattering condition. Lidar ratios are in the 20-40 range for clouds at heights of 12.5-15 km and are smaller than approximately 30 in height above 15 km. Clouds are usually optically thin for temperatures below approximately -65 degrees C, and in this region the optical depth tends to decrease with height. The depolarization ratio is found to increase with a height at 11-15 km and smaller than 0.3 above 16 km. The variation in the depolarization ratio with the lidar ratio was also reported. The lidar and depolarization ratios were discussed in terms of the types of hexagonal ice crystals. PMID:12396200

  9. The diversity of the N2O reducers matters for the N2O:N2 denitrification end-product ratio across an annual and a perennial cropping system

    PubMed Central

    Domeignoz-Horta, Luiz A.; Spor, Aymé; Bru, David; Breuil, Marie-Christine; Bizouard, Florian; Léonard, Joël; Philippot, Laurent

    2015-01-01

    Agriculture is the main source of terrestrial emissions of N2O, a potent greenhouse gas and the main cause of ozone layer depletion. The reduction of N2O into N2 by microorganisms carrying the nitrous oxide reductase gene (nosZ) is the only biological process known to eliminate this greenhouse gas. Recent studies showed that a previously unknown clade of N2O-reducers was related to the capacity of the soil to act as an N2O sink, opening the way for new strategies to mitigate emissions. Here, we investigated whether the agricultural practices could differently influence the two N2O reducer clades with consequences for denitrification end-products. The abundance of N2O-reducers and producers was quantified by real-time PCR, and the diversity of both nosZ clades was determined by 454 pyrosequencing. Potential N2O production and potential denitrification activity were used to calculate the denitrification gaseous end-product ratio. Overall, the results showed limited differences between management practices but there were significant differences between cropping systems in both the abundance and structure of the nosZII community, as well as in the [rN2O/r(N2O+N2)] ratio. More limited differences were observed in the nosZI community, suggesting that the newly identified nosZII clade is more sensitive than nosZI to environmental changes. Potential denitrification activity and potential N2O production were explained mainly by the soil properties while the diversity of the nosZII clade on its own explained 26% of the denitrification end-product ratio, which highlights the importance of understanding the ecology of this newly identified clade of N2O reducers for mitigation strategies. PMID:26441904

  10. The diversity of the N2O reducers matters for the N2O:N2 denitrification end-product ratio across an annual and a perennial cropping system.

    PubMed

    Domeignoz-Horta, Luiz A; Spor, Aymé; Bru, David; Breuil, Marie-Christine; Bizouard, Florian; Léonard, Joël; Philippot, Laurent

    2015-01-01

    Agriculture is the main source of terrestrial emissions of N2O, a potent greenhouse gas and the main cause of ozone layer depletion. The reduction of N2O into N2 by microorganisms carrying the nitrous oxide reductase gene (nosZ) is the only biological process known to eliminate this greenhouse gas. Recent studies showed that a previously unknown clade of N2O-reducers was related to the capacity of the soil to act as an N2O sink, opening the way for new strategies to mitigate emissions. Here, we investigated whether the agricultural practices could differently influence the two N2O reducer clades with consequences for denitrification end-products. The abundance of N2O-reducers and producers was quantified by real-time PCR, and the diversity of both nosZ clades was determined by 454 pyrosequencing. Potential N2O production and potential denitrification activity were used to calculate the denitrification gaseous end-product ratio. Overall, the results showed limited differences between management practices but there were significant differences between cropping systems in both the abundance and structure of the nosZII community, as well as in the [rN2O/r(N2O+N2)] ratio. More limited differences were observed in the nosZI community, suggesting that the newly identified nosZII clade is more sensitive than nosZI to environmental changes. Potential denitrification activity and potential N2O production were explained mainly by the soil properties while the diversity of the nosZII clade on its own explained 26% of the denitrification end-product ratio, which highlights the importance of understanding the ecology of this newly identified clade of N2O reducers for mitigation strategies. PMID:26441904

  11. Sialyltransferase and Neuraminidase Levels/Ratios and Sialic Acid Levels in Peripheral Blood B Cells Correlate with Measures of Disease Activity in Patients with Systemic Lupus Erythematosus and Rheumatoid Arthritis: A Pilot Study

    PubMed Central

    Liou, Lieh-bang; Huang, Che-ching

    2016-01-01

    Objective We attempted to determine whether the level of enzymes sialyltransferase (ST) and neuraminidase (Neu) and sialic acid (SIA) in patients with systemic lupus erythematosus (SLE) correlates with the SLE Disease Activity Index (SLEDAI) and in patients with rheumatoid arthritis (RA) correlates with the Disease Activity Score28 (DAS28). Methods We examined cell-surface levels of ST6Gal-1, Neu1, ST3Gal-1, Neu3, α-2,6-SIA, and α-2,3-SIA by using fluorescent anti-enzyme antibodies, fluorescent-conjugated Sambucus nigra lectin, and fluorescent-conjugated Maackia amurensis lectin on blood cells in SLE and RA patients and assessed correlations of these levels with SLEDAI and with DAS28. Areas under the curve (AUC) were calculated for different variables against SLEDAI. Results The B-cell ST3Gal-1/Neu3 ratio positively correlated with SLEDAI scores (ρ = 0.409 and P = 0.002, statistically significant after Bonferroni’ correction for multiple analyses.). It was supported by the inverse correlation of B-cell Neu3 levels with SLEDAI scores (ρ = −0.264, P = 0.048). The B-cell ST3Gal-1/Neu3 ratio against SLEDAI yielded an AUC of 0.689, which was comparable to that of anti-dsDNA levels at 0.635. In contrast, both ST3Gal-1 and Neu3 levels of RA B cells (r = 0.376, P = 0.013; r = 0.425, P = 0.005, respectively) correlated positively with high disease-activity DAS28 scores. Conclusion B-cell ST3Gal-1/Neu3 ratios in SLE and B-cell ST3Gal-1 and Neu3 levels in RA with high disease-activity DAS28 scores correlated with disease activity measures and may be useful in monitoring disease activities. PMID:26981635

  12. Effects of Al2O3 and CaO/SiO2 Ratio on Phase Equilbria in the ZnO-"FeO"-Al2O3-CaO-SiO2 System in Equilibrium with Metallic Iron

    NASA Astrophysics Data System (ADS)

    Zhao, Baojun; Hayes, Peter C.; Jak, Evgueni

    2011-02-01

    The phase equilibria and liquidus temperatures in the ZnO-"FeO"-Al2O3-CaO-SiO2 system in equilibrium with metallic iron have been determined experimentally in the temperature range 1383 K to 1573 K (1150 C to 1300 C). The experimental conditions were selected to characterize lead blast furnace and imperial smelting furnace slags. The results are presented in a form of pseudoternary sections ZnO-"FeO"-(Al2O3 + CaO + SiO2) with fixed CaO/SiO2 and (CaO + SiO2)/Al2O3 ratios. It was found that wustite and spinel are the major primary phases in the composition range investigated. Effects of Al2O3 concentration as well as the CaO/SiO2 ratio on the primary phase field, the liquidus temperature, and the partitioning of ZnO between liquid and solid phases have been discussed for zinc-containing slags.

  13. Multispectral expert system spectropyrometer and its uses in industry and research

    NASA Astrophysics Data System (ADS)

    Felice, Ralph A.

    2004-04-01

    A multi-wavelength expert-system pyrometer based on a grating spectrophotometer has been able to overcome many well-known difficulties of pyrometry. These include unknown, changing, and/or spectral dependence of emissivity as well as environmental absorption of radiation. In addition to a spectrophotometer and the usual optics, the instrument includes a computer which analyzes each measurement and then returns the temperature, the tolerance (a real-time measure of accuracy), and the signal strength (a quantity directly related to the emissivity at a chosen wavelength). The instrument can save the input data, the thermal spectrum, for each temperature measurement. Accuracy to 0.10% is routinely achieved.

  14. Progressive Ratio Schedules of Reinforcement

    PubMed Central

    Killeen, Peter R.; Posadas-Sanchez, Diana; Johansen, Espen Borg; Thrailkill, Eric A.

    2009-01-01

    Pigeons pecks produced grain under progressive ratio (PR) schedules, whose response requirements increased systematically within sessions. Experiment 1 compared arithmetic (AP) and geometric (GP) progressions. Response rates increased as a function of the component ratio requirement, then decreased linearly (AP) or asymptotically (GP). Experiment 2 found the linear decrease in AP rates to be relatively independent of step size. Experiment 3 showed pausing to be controlled by the prior component length, which predicted the differences between PR and regressive ratio schedules found in Experiment 4. When the longest component ratios were signaled by different key colors, rates at moderate ratios increased, demonstrating control by forthcoming context. Models for response rate and pause duration described performance on AP schedules; GP schedules required an additional parameter representing the contextual reinforcement. PMID:19159161

  15. 30 CFR 36.44 - Maximum allowable fuel : air ratio.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Maximum allowable fuel : air ratio. 36.44... TRANSPORTATION EQUIPMENT Test Requirements 36.44 Maximum allowable fuel : air ratio. (a) When an engine is... adjustment of the fuel-injection system shall be accepted. The maximum fuel : air ratio determined from...

  16. A Study on Usage of on-site Multi-monitoring System in Laser Processing of Paper Materials

    NASA Astrophysics Data System (ADS)

    Piili, Heidi

    Laser technology provides advantages for paper material processing as it is non-contact method and provides freedom of geometry and reliable technology for non-stop production. Reason for low utilization of lasers in paper manufacturing is lack of published research. This is main reason to study utilization of on-site multi-monitoring system (MMS) in characterization of interaction between laser beam and paper materials. Target of MMS is to be able to control processing of paper, but also to get better understanding of basic phenomena. Laser equipment used was TRUMPF TLF 2700 CO2 laser (wavelength 10.6 ?m) with power range of 190-2500 W. MMS consisted of spectrometer, pyrometer and active illumination imaging system. This on-site study was carried out by treating dried kraft pulp (grammage of 67 g m-2) with different laser power levels, focal plane position settings and interaction times. It was concluded that spectrometer and pyrometer are best devices in MMS; set-up of them to laser process is easy, they detect data fast enough and analysis of data is easy afterwards. Active illumination imaging system is capable for capturing images of different phases of interaction but analysis of images is time-consuming. When active illumination imaging system is combined with spectrometer and pyrometer i.e. using of MMS, it reveals basic phenomena occurring during interaction. For example, it was noticed that holes created after laser exposure are formed gradually. Firstly, small hole is formed to interaction area and after that hole expands, until interaction is ended.

  17. System and method for investigating sub-surface features and 3D imaging of non-linear property, compressional velocity VP, shear velocity VS and velocity ratio VP/VS of a rock formation

    DOEpatents

    Vu, Cung Khac; Skelt, Christopher; Nihei, Kurt; Johnson, Paul A.; Guyer, Robert; Ten Cate, James A.; Le Bas, Pierre-Yves; Larmat, Carene S.

    2015-06-02

    A system and a method for generating a three-dimensional image of a rock formation, compressional velocity VP, shear velocity VS and velocity ratio VP/VS of a rock formation are provided. A first acoustic signal includes a first plurality of pulses. A second acoustic signal from a second source includes a second plurality of pulses. A detected signal returning to the borehole includes a signal generated by a non-linear mixing process from the first and second acoustic signals in a non-linear mixing zone within an intersection volume. The received signal is processed to extract the signal over noise and/or signals resulting from linear interaction and the three dimensional image of is generated.

  18. Arcjet nozzle area ratio effects

    NASA Technical Reports Server (NTRS)

    Curran, Francis M.; Sarmiento, Charles J.; Birkner, Bjorn W.; Kwasny, James

    1990-01-01

    An experimental investigation was conducted to determine the effect of nozzle area ratio on the operating characteristics and performance of a low power dc arcjet thruster. Conical thoriated tungsten nozzle inserts were tested in a modular laboratory arcjet thruster run on hydrogen/nitrogen mixtures simulating the decomposition products of hydrazine. The converging and diverging sides of the inserts had half angles of 30 and 20 degrees, respectively, similar to a flight type unit currently under development. The length of the diverging side was varied to change the area ratio. The nozzle inserts were run over a wide range of specific power. Current, voltage, mass flow rate, and thrust were monitored to provide accurate comparisons between tests. While small differences in performance were observed between the two nozzle inserts, it was determined that for each nozzle insert, arcjet performance improved with increasing nozzle area ratio to the highest area ratio tested and that the losses become very pronounced for area ratios below 50. These trends are somewhat different than those obtained in previous experimental and analytical studies of low Re number nozzles. It appears that arcjet performance can be enhanced via area ratio optimization.

  19. Arcjet Nozzle Area Ratio Effects

    NASA Technical Reports Server (NTRS)

    Curran, Francis M.; Sarmiento, Charles J.; Birkner, Bjorn W.; Kwasny, James

    1990-01-01

    An experimental investigation was conducted to determine the effect of nozzle area ratio on the operating characteristics and performance of a low power dc arcjet thruster. Conical thoriated tungsten nozzle inserts were tested in a modular laboratory arcjet thruster run on hydrogen/nitrogen mixtures simulating the decomposition products of hydrazine. The converging and diverging sides of the inserts had half angles of 30 and 20 degrees, respectively, similar to a flight type unit currently under development. The length of the diverging side was varied to change the area ratio. The nozzle inserts were run over a wide range of specific power. Current, voltage, mass flow rate, and thrust were monitored to provide accurate comparisons between tests. While small differences in performance were observed between the two nozzle inserts, it was determined that for each nozzle insert, arcjet performance improved with increasing nozzle area ratio to the highest area ratio tested and that the losses become very pronounced for area ratios below 50. These trends are somewhat different than those obtained in previous experimental and analytical studies of low Re number nozzles. It appears that arcjet performance can be enhanced via area ratio optimization.

  20. Pressure Ratio to Thermal Environments

    NASA Technical Reports Server (NTRS)

    Lopez, Pedro; Wang, Winston

    2012-01-01

    A pressure ratio to thermal environments (PRatTlE.pl) program is a Perl language code that estimates heating at requested body point locations by scaling the heating at a reference location times a pressure ratio factor. The pressure ratio factor is the ratio of the local pressure at the reference point and the requested point from CFD (computational fluid dynamics) solutions. This innovation provides pressure ratio-based thermal environments in an automated and traceable method. Previously, the pressure ratio methodology was implemented via a Microsoft Excel spreadsheet and macro scripts. PRatTlE is able to calculate heating environments for 150 body points in less than two minutes. PRatTlE is coded in Perl programming language, is command-line-driven, and has been successfully executed on both the HP and Linux platforms. It supports multiple concurrent runs. PRatTlE contains error trapping and input file format verification, which allows clear visibility into the input data structure and intermediate calculations.

  1. Continually variable transmission having fixed ratio and variable ratio mechanisms

    SciTech Connect

    Moan, R.D

    1989-06-06

    This patent describes a transmission for producing a stepless, continually variable range of ratios of the speed of its output to its input comprising: a fluid coupling having an impeller adapted for connection to a power source and a turbine hydrodynamically connected to the impeller; as planetary gearset having a ring gear, a sun gear, a first set of planet pinions meshing with the sun gear, a second set of planet pinions meshing with the first set of pinions and with the ring gear, and a pinion carrier on which the first and second sets of pinions are rotatably supported; first drive means drivable connecting the turbine and the sun gear for producing a variable speed ratio therebetween having a range between an underdrive ratio and an overdrive ratio; second drive means drivably connecting the impeller and the ring gear for producing a fixed speed ratio therebetween; a first clutch means for drivably connecting and disconnecting the ring gear and the second drive means; and a second clutch means for drivably connecting and disconnecting the first drive means and the pinion carrier.

  2. A novel measurement scheme of the polarization extinction ratio

    NASA Astrophysics Data System (ADS)

    Ma, Huihui; Yuan, Xueguang; Zhang, Yangan; Hong, Yan; Wang, Limeng; Zhang, Yue

    2015-08-01

    In this paper, we mainly introduce a novel measurement system of the polarization extinction ratio(PBSBC system). Here, because the main optical components of the system is PBS and PBC, so we call this system PBSBC system. First of all, we introduce the principle of method of measuring the polarization extinction ratio by drawing a circle on the Poincare. Secondly, we present the system block diagram of PBSBC system, and design an experimental system to theoretically and experimentally investigate the performance of this system though the multiple groups of experimental data collected under the same condition. Finally, we could show that it is compatible with the analysis in PBSBC system.

  3. CO isotopologue ratios in the solar photosphere

    NASA Astrophysics Data System (ADS)

    Lyons, James; Gharib-Nezhad, Ehsan; Ayres, Thomas

    2015-08-01

    Determination of the oxygen isotope ratios in the solar photosphere is essential to constraining the formation environment of the solar system. The solar CO fundamental and first-overtone bands were previously measured by the shuttle-borne ATMOS Fourier transform spectrometer (FTS), and with the National Solar Observatory FTS on the McMath-Pierce telescope at Kitt Peak. Analyzing the rovibrational bands from these photospheric spectra, a 3D convection model was employed to calculate ratios with improved uncertainties (16O/17O=2738118 and 16O/18O =51110 Ayres et al. 2013), which fall between the terrestrial values and those inferred from solar wind measurements by the Genesis spacecraft. However, differences in published CO dipole moment functions yielded a range of isotopic ratios spanning ~ 3 % in ?18O. Here we re-evaluate the CO dipole moment function in order to obtain more accurate isotope ratios for the photosphere. We used a new set of dipole moments from HITEMP which were accurately determined by both semi-empirical and ab initio methods. Preliminary values of isotope ratios using the new dipole moments are in better agreement with the inferred photosphere values from Genesis, showing that the solar photosphere is isotopically similar to primitive inclusions in meteorites, but different from the terrestrial planets by ~ 6 %. New spectral observations are needed to reduce uncertainties in photospheric C17O abundances.

  4. Peak-to-average power ratio reduction in orthogonal frequency division multiplexing visible light communications system using a combination of a genetic algorithm and a hill-climbing algorithm

    NASA Astrophysics Data System (ADS)

    Xiao, Wei; Deng, Honggui; Jiang, Fangqing; Zhu, Kaicheng; Yin, Linzi

    2015-03-01

    The orthogonal frequency division multiplexing (OFDM) modulation technique has been used widely in visible light communications (VLC) systems to combat intersymbol interference. At the same time, the inherent drawback of OFDM with a high peak-to-average power ratio (PAPR) is brought into OFDM visible light communications (VLC-OFDM). Furthermore, considering the limited dynamic range characteristics of light-emitting diodes, the performance degradation caused by a high PAPR is more serious in VLC-OFDM. In this paper, we propose a partial transmit sequence (PTS) technique based on the combination of a genetic algorithm (GA) and a hill-climbing algorithm (GH-PTS) to solve the problem of high PAPR. GH-PTS is a modified PTS technique based on GA-PTS. Essentially, GH-PTS is a local optimization of GA-PTS. Simulation results show that the optimized technique is able to reduce PAPR more effectively without any loss of bit error rate performance than the GA-PTS technique in VLC-OFDM system.

  5. Low-speed tests of a high-aspect-ratio, supercritical-wing transport model equipped with a high-lift flap system in the Langley 4- by 7-meter and Ames 12-foot pressure tunnels

    NASA Technical Reports Server (NTRS)

    Morgan, H. L., Jr.; Kjelgaard, S. O.

    1983-01-01

    The Ames 12-Foot Pressure Tunnel was used to determine the effects of Reynolds number on the static longitudinal aerodynamic characteristics of an advanced, high-aspect-ratio, supercritical wing transport model equipped with a full span, leading edge slat and part span, double slotted, trailing edge flaps. The model had a wing span of 7.5 ft and was tested through a free stream Reynolds number range from 1.3 to 6.0 x 10 to 6th power per foot at a Mach number of 0.20. Prior to the Ames tests, an investigation was also conducted in the Langley 4 by 7 Meter Tunnel at a Reynolds number of 1.3 x 10 to 6th power per foot with the model mounted on an Ames strut support system and on the Langley sting support system to determine strut interference corrections. The data obtained from the Langley tests were also used to compare the aerodynamic charactertistics of the rather stiff, 7.5-ft-span steel wing model tested during this investigation and the larger, and rather flexible, 12-ft-span aluminum-wing model tested during a previous investigation. During the tests in both the Langley and Ames tunnels, the model was tested with six basic wing configurations: (1) cruise; (2) climb (slats only extended); (3) 15 deg take-off flaps; (4) 30 deg take-off flaps; (5) 45 deg landing flaps; and (6) 60 deg landing flaps.

  6. Poisson's ratio and modern materials.

    PubMed

    Greaves, G N; Greer, A L; Lakes, R S; Rouxel, T

    2011-11-01

    In comparing a material's resistance to distort under mechanical load rather than to alter in volume, Poisson's ratio offers the fundamental metric by which to compare the performance of any material when strained elastically. The numerical limits are set by and -1, between which all stable isotropic materials are found. With new experiments, computational methods and routes to materials synthesis, we assess what Poisson's ratio means in the contemporary understanding of the mechanical characteristics of modern materials. Central to these recent advances, we emphasize the significance of relationships outside the elastic limit between Poisson's ratio and densification, connectivity, ductility and the toughness of solids; and their association with the dynamic properties of the liquids from which they were condensed and into which they melt. PMID:22020006

  7. Measurement of Tau branching ratios

    NASA Astrophysics Data System (ADS)

    Decamp, D.; Deschizeaux, B.; Goy, C.; Lees, J.-P.; Minard, M.-N.; Alemany, R.; Crespo, J. M.; Delfino, M.; Fernandez, E.; Gaitan, V.; Garrido, Ll.; Mir, Ll. M.; Pacheco, A.; Catanesi, M. G.; Creanza, D.; de Palma, M.; Farilla, A.; Iaselli, G.; Maggi, G.; Maggi, M.; Natali, S.; Nuzzo, S.; Quattromini, M.; Ranieri, A.; Raso, G.; Romano, F.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Hu, H.; Huang, D.; Huang, X.; Lin, J.; Lou, J.; Qiao, C.; Ruan, T.; Wang, T.; Xie, Y.; Xu, D.; Xu, R.; Zhang, J.; Zhao, W.; Atwood, W. B.; Bauerdick, L. A. T.; Bird, F.; Blucher, E.; Bonvicini, G.; Bossi, F.; Boudreau, J.; Burnett, T. H.; Drevermann, H.; Forty, R. W.; Grab, C.; Hagelberg, R.; Haywood, S.; Hilgart, J.; Jost, B.; Kasemann, M.; Knobloch, J.; Lacourt, A.; Lanon, E.; Lehraus, I.; Lohse, T.; Lusiani, A.; Marchioro, A.; Martinez, M.; Mato, P.; Menary, S.; Meyer, T.; Minten, A.; Miotto, A.; Miquel, R.; Moser, H.-G.; Nash, J.; Palazzi, P.; Ranjard, F.; Redlinger, G.; Rolandi, L.; Roth, A.; Rothberg, J.; Saich, M.; Schlatter, D.; Schmelling, M.; Tejessy, W.; Wachsmuth, H.; Wasserbaech, S.; Wiedenmann, W.; Witzeling, W.; Wotschack, J.; Ajaltouni, Z.; Badaud, F.; Bardadin-Otwinowska, M.; Bencheikh, A. M.; El Fellous, R.; Falvard, A.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Montret, J.-C.; Pallin, D.; Perret, P.; Pietrzyk, B.; Proriol, J.; Prulhire, F.; Stimpfl, G.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Mllerud, R.; Nilsson, B. S.; Efthymiopoulos, I.; Simopoulos, E.; Vayaki, A.; Badier, J.; Blondel, A.; Bonneaud, G.; Brient, J. C.; Fouque, G.; Gamess, A.; Harvey, J.; Orteu, S.; Rosowsky, A.; Roug, A.; Rumpf, M.; Tanaka, R.; Videau, H.; Candlin, D. J.; Veitch, E.; Moneta, L.; Parrini, G.; Corden, M.; Georgiopoulos, C.; Ikeda, M.; Lannutti, J.; Levinthal, D.; Mermikides, M.; Sawyer, L.; Antonelli, A.; Baldini, R.; Bencivenni, G.; Bologna, G.; Campana, P.; Capon, G.; Cerutti, F.; Chiarella, V.; D'Ettore-Piazzoli, B.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Passalacqua, L.; Pepe-Altarelli, M.; Picchi, P.; Zografou, P.; Altoon, B.; Boyle, O.; Colrain, P.; Halley, A. W.; Ten Have, I.; Lynch, J. G.; Maitland, W.; Morton, W. T.; Raine, C.; Scarr, J. M.; Smith, K.; Thompson, A. S.; Turnbull, R. M.; Brandl, B.; Braun, O.; Geiges, R.; Geweniger, C.; Hanke, P.; Hepp, V.; Kluge, E. E.; Maumary, Y.; Putzer, A.; Rensch, B.; Stahl, A.; Tittel, K.; Wunsch, M.; Belk, A. T.; Beuselinck, R.; Binnie, D. M.; Cameron, W.; Cattaneo, M.; Dornan, P. J.; Dugeay, S.; Greene, A. M.; Hassard, J. F.; Lieske, N. M.; Patton, S. J.; Payne, D. G.; Phillips, M. J.; Sedgbeer, J. K.; Taylor, G.; Tomalin, I. R.; Wright, A. G.; Girtler, P.; Kuhn, D.; Rudolph, G.; Bowdery, C. K.; Broodbeck, T. J.; Finch, A. J.; Foster, F.; Hughes, G.; Jackson, D.; Keemer, N. R.; Nuttall, M.; Patel, A.; Sloan, T.; Snow, S. W.; Whelan, E. P.; Barczewski, T.; Kleinknecht, K.; Raab, J.; Renk, B.; Roehn, S.; Sander, H.-G.; Schmidt, H.; Steeg, F.; Walther, S. M.; Wolf, B.; Aubert, J.-J.; Benchouk, C.; Bernard, V.; Bonissent, A.; Carr, J.; Coyle, P.; Drinkhard, J.; Etienne, F.; Papalexiou, S.; Payre, P.; Qian, Z.; Rousseau, D.; Schwemling, P.; Talby, M.; Adlung, S.; Becker, H.; Blum, W.; Brown, D.; Cattaneo, P.; Cowan, G.; Dehning, B.; Dietl, H.; Dydak, F.; Fernandez-Bosman, M.; Hansl-Kosanecka, T.; Jahn, A.; Kozanecki, W.; Lange, E.; Lauber, J.; Ltjens, G.; Lutz, G.; Mnner, W.; Richter, R.; Rotscheidt, H.; Schrder, J.; Schwarz, A. S.; Settles, R.; Stierlin, U.; Stiegler, U.; Denis, R. St.; Takashima, M.; Thomas, J.; Wolf, G.; Bertin, V.; Boucrot, J.; Callot, O.; Chen, X.; Cordier, A.; Davier, M.; Grivaz, J.-F.; Heusse, Ph.; Janot, P.; Kim, D. W.; Le Diberder, F.; Lefranois, J.; Lutz, A.-M.; Schune, M.-H.; Veillet, J.-J.; Videau, I.; Zhang, Z.; Zomer, F.; Abbaneo, D.; Amendolia, S. R.; Bagliesi, G.; Batignani, G.; Bosisio, L.; Bottigli, U.; Bradaschia, C.; Carpinelli, M.; Ciocci, M. A.; Dell'Orso, R.; Ferrante, I.; Fidecaro, F.; Fo, L.; Focardi, E.; Forti, F.; Gatto, C.; Grassi, A.; Giorgi, M. A.; Ligabue, F.; Mannelli, E. B.; Marrocchesi, P. S.; Messineo, A.; Palla, F.; Sanguinetti, G.; Steinberger, J.; Tenchini, R.; Tonelli, G.; Triggiani, G.; Vannini, C.; Venturi, A.; Verdini, P. G.; Walsh, J.; Carter, J. M.; Green, M. G.; March, P. V.; Medcalf, T.; Quasi, I. S.; Strong, J. A.; West, L. R.; Wildish, T.; Botterill, D. R.; Clifft, R. W.; Edgecock, T. R.; Edwards, M.; Fisher, S. M.; Jones, T. J.; Norton, P. R.; Salmon, D. P.; Thompson, J. C.; Bloch-Devaux, B.; Colas, P.; Locci, E.; Loucatos, S.; Monnier, E.; Perez, P.; Perlas, J. A.; Perrier, F.; Rander, J.; Renardy, J.-F.; Roussarie, A.; Schuller, J.-P.; Schwindling, J.; Vallage, B.; Ashman, J. G.; Booth, C. N.; Buttar, C.; Carney, R. E.

    1992-06-01

    Using the data accumulated at LEP in 1989 and 1990 with the ALEPH detector, the inclusive and exclusive branching ratios of the ? lepton have been measured assuming lepton universality in Z 0 decays. The inclusive branching fractions for the ? decay into one, three, and five charged particles have been determined to be (85.450.97)%, (14.350.48)%, and (0.100.05)%, respectively, in agreement with the world averages. New undetected decay modes are determined to have a branching fraction of less than 2.1% at 95% CL. The measured branching ratios for quasi-exclusive channels are slightly larger than, but consistent with the world averages, except for the modes ??3 hadrons+ v ? and ??hadron+2?0 v ? , which are significantly larger. These latter branching ratios have been found to be (9.50.7)% and (10.21.1)%, respectively. The sum of all the measured quasi-exclusive branching ratios is (100.41.8)%. A fully exclusive analysis of modes with neutral pions shows no evidence for new photonic decay modes with a branching fraction limit of 3.4% at 95% CL.

  8. Gender Ratios for Reading Difficulties

    ERIC Educational Resources Information Center

    Hawke, Jesse L.; Olson, Richard K.; Willcut, Erik G.; Wadsworth, Sally J.; DeFries, John C.

    2009-01-01

    The prevalence of reading difficulties is typically higher in males than females in both referred and research-identified samples, and the ratio of males to females is greater in more affected samples. To explore possible gender differences in reading performance, we analysed data from 1133 twin pairs in which at least one member of each pair had…

  9. Air/fuel ratio detector

    SciTech Connect

    Yamada, T.; Hirate, S.

    1986-10-07

    This patent describes a method for detecting the air/fuel ratio of exhaust gas with a detector comprising an electrochemical cell sensor element and an oxygen pump element. Each element is in the form of an oxygen-ion-conductive solid electrolyte having a porous electrode formed on both sides thereof. The electrochemical cell sensor element being disposed to face the pump element with a small gap therebetween, exposed to the exhaust gas and an air compartment which is open to the atmosphere being formed on that side of the pump element which is opposite to the small gap. An electric current is caused to flow through the oxygen pump element so that oxygen is pumped into the small gap from the air compartment or in the opposite direction, thereby producing an electromotive force in the sensor element. The electromotive force and the current flowing through the pump element is used as a basis for detecting the air/fuel ratio of the exhaust gas. The improvement described here is wherein a sufficient amount of current to pump oxygen from the air compartment into the small gap is caused to flow through the oxygen pump element so as to produce an abrupt change in the electromotive force of the sensor element at a stoichiometric air/fuel ratio. The electromotive force of the sensor element is used to determine whether a present air/fuel ratio is in the fuel-rich or fuel-lean region.

  10. A Ratio Explanation for Evolution.

    ERIC Educational Resources Information Center

    Riss, Pam Helfers

    1993-01-01

    Describes hands-on physical anthropology activities for teaching students about evolution. Using evidence found in hominid skulls, students conduct investigations that involve calculating ratios. Eight full-page photographs of skulls from the program Stones and Bones are included. (PR)

  11. Follistatin-like Protein 1 and the Ferritin/Erythrocyte Sedimentation Rate Ratio Are Potential Biomarkers for Dysregulated Gene Expression and Macrophage Activation Syndrome in Systemic Juvenile Idiopathic Arthritis

    PubMed Central

    Gorelik, Mark; Fall, Ndate; Altaye, Mekibib; Barnes, Michael G.; Thompson, Susan D.; Grom, Alexei A.; Hirsch, Raphael

    2013-01-01

    Objective Follistatin-like protein 1 (FSTL-1) is a secreted glycoprotein overexpressed in certain inflammatory diseases. Our objective was to correlate FSTL-1 levels with gene expression, known biomarkers, and measures of disease activity in systemic juvenile idiopathic arthritis (sJIA), including macrophage activation syndrome (MAS). Methods FSTL-1 serum levels were measured by ELISA in 28 patients with sJIA, including 7 patients who developed MAS, and 30 healthy controls. Levels were correlated with erythrocyte sedimentation rate (ESR), ferritin, and soluble interleukin-2 receptor-α (sIL-2Rα). Gene expression based on FSTL-1 levels was analyzed in peripheral blood mononuclear cells (PBMC). Results Serum levels of FSTL-1 were elevated at time of presentation of sJIA (mean 200.7 ng/ml) and decreased to normal (mean 133.7 ng/ml) over 24 months (p < 0.01). FSTL-1 levels were markedly elevated during acute MAS (mean 279.8 ng/ml) and decreased to normal following treatment (p < 0.001). FSTL-1 levels correlated with serum markers of inflammation, including sIL-2Rα and ferritin. Ferritin/ESR ratio was superior to ferritin, sIL-2Rα, and FSTL-1 in discriminating MAS from new-onset sJIA. PBMC from patients with FSTL-1 levels > 200 ng/ml showed altered expression of genes related to innate immunity, erythropoiesis, and natural killer cell dysfunction. Two patients with the highest FSTL-1 levels at disease onset (> 300 ng/ml) ultimately developed MAS. Conclusion Elevated pretreatment serum FSTL-1 levels in sJIA are associated with dysregulated gene expression suggestive of occult MAS, and may have utility in predicting progression to overt MAS. Ferritin/ESR ratio may be superior to ferritin alone in discriminating overt MAS from new-onset sJIA. (First Release May 15 2013; J Rheumatol 2013;40:1191–9; doi:10.3899/jrheum.121131) PMID:23678162

  12. Thermal evolution and Urey ratio of Mars

    NASA Astrophysics Data System (ADS)

    Plesa, A.-C.; Tosi, N.; Grott, M.; Breuer, D.

    2015-05-01

    The upcoming InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) mission, to be launched in 2016, will carry out the first in situ Martian heat flux measurement, thereby providing an important baseline to constrain the present-day heat budget of the planet and, in turn, the thermal and chemical evolution of its interior. The surface heat flux can be used to constrain the amount of heat-producing elements present in the interior if the Urey ratio (Ur)the planet's heat production rate divided by heat lossis known. We used numerical simulations of mantle convection to model the thermal evolution of Mars and determine the present-day Urey ratio for a variety of models and parameters. We found that Ur is mainly sensitive to the efficiency of mantle cooling, which is associated with the temperature dependence of the viscosity (thermostat effect), and to the abundance of long-lived radiogenic isotopes. If the thermostat effect is efficient, as expected for the Martian mantle, assuming typical solar system values for the thorium-uranium ratio and a bulk thorium concentration, simulations show that the present-day Urey ratio is approximately constant, independent of model parameters. Together with an estimate of the average surface heat flux as determined by InSight, models of the amount of heat-producing elements present in the primitive mantle can be constrained.

  13. Fission Product Ratios as Treaty Monitoring Discriminants

    SciTech Connect

    Miley, Harry S.; Bowyer, Ted W.; Greenwood, Lawrence R.; Arthur, Richard J.

    2008-05-15

    The International Monitoring System (IMS) of the Comprehensive Test Ban Treaty Organization (CTBTO) is currently under construction. The IMS is intended for monitoring of nuclear explosions. The radionuclide branch of the IMS monitors the atmosphere for short-lived radioisotopes indicative of a nuclear weapon test, and includes field collection and measurement stations, as well as laboratories to provide reanalysis of the most important samples and a quality control function. The Pacific Northwest National Laboratory in Richland, Washington hosts the United States IMS laboratory, with the designation “RL16.” Since acute reactor containment failures and chronic reactor leakage may also produce similar isotopes, it is tempting to compute ratios of detected isotopes to determine the relevance of an event to the treaty or agreement in question. In this paper we will note several shortcomings of simple isotopic ratios: (1) fractionation of different chemical species, (2) difficulty in comparing isotopes within a single element, (3) the effect of unknown decay times. While these shortcomings will be shown in the light of an aerosol sample, several of the problems extend to xenon isotopic ratios. The result of the difficulties listed above is that considerable human expertise will be required to convert a simple mathematical ratio into a criterion which will reliably categorize an event as ‘reactor’ or ‘weapon’.

  14. The Prigogine-Defay ratio revisited.

    PubMed

    Schmelzer, Jrn W P; Gutzow, Ivan

    2006-11-14

    One of the basic characteristics of the glass transition, the Prigogine-Defay ratio, connecting jumps of the thermal expansion coefficient, isothermal compressibility, and isobaric specific heat capacity in vitrification is rederived in the framework of the thermodynamics of irreversible processes employing the order-parameter concept introduced by de Donder and van Rysselberghe [Thermodynamic Theory of Affinity (Stanford University Press, Stanford, 1936)]. In our analysis, glass-forming liquids and glasses are described by only one structural order parameter. However, in contrast to previous approaches to the derivation of this ratio, the process of vitrification is treated not in terms of Simon's simplified model [Z. Anorg. Allg. Chem. 203, 219 (1931)] as a freezing-in process proceeding at some sharp temperature, the glass transition temperature T(g), but in some finite temperature interval accounting appropriately for the nonequilibrium character of vitrifying systems in this temperature range. As the result of the theoretical analysis, we find, in particular, that the Prigogine-Defay ratio generally has to have values larger than 1 for vitrification in cooling processes. Quantitative estimates of the Prigogine-Defay ratio are given utilizing a mean-field lattice-hole model of glass-forming melts. Some further consequences are derived concerning the behavior of thermodynamic coefficients, in particular, of Young's modulus in vitrification. The theoretical results are found to be in good agreement with experimental data. PMID:17115769

  15. Energy Balance Bowen Ratio Station (EBBR) Handbook

    SciTech Connect

    Cook, DR

    2011-02-23

    The energy balance Bowen ratio (EBBR) system produces 30-minute estimates of the vertical fluxes of sensible and latent heat at the local surface. Flux estimates are calculated from observations of net radiation, soil surface heat flux, and the vertical gradients of temperature and relative humidity (RH). Meteorological data collected by the EBBR are used to calculate bulk aerodynamic fluxes, which are used in the Bulk Aerodynamic Technique (BA) EBBR value-added product (VAP) to replace sunrise and sunset spikes in the flux data. A unique aspect of the system is the automatic exchange mechanism (AEM), which helps to reduce errors from instrument offset drift.

  16. Optomechanical Raman-ratio thermometry

    NASA Astrophysics Data System (ADS)

    Purdy, T. P.; Yu, P.-L.; Kampel, N. S.; Peterson, R. W.; Cicak, K.; Simmonds, R. W.; Regal, C. A.

    2015-09-01

    The temperature dependence of the asymmetry between Stokes and anti-Stokes Raman scattering can be exploited for self-calibrating, optically based thermometry. In the context of cavity optomechanics, we observe the cavity-enhanced scattering of light interacting with the standing-wave drumhead modes of a Si3N4 membrane mechanical resonator. The ratio of the amplitude of Stokes to anti-Stokes scattered light is used to measure temperatures of optically cooled mechanical modes, down to the level of a few vibrational quanta. We demonstrate that the Raman-ratio technique allows the measurement of the physical temperature of our device over a range extending from cryogenic temperatures to within an order of magnitude of room temperature.

  17. GUT Scale Fermion Mass Ratios

    NASA Astrophysics Data System (ADS)

    Spinrath, Martin

    2014-10-01

    We present a series of recent works related to group theoretical factors from GUT symmetry breaking which lead to predictions for the ratios of quark and lepton Yukawa couplings at the unification scale. New predictions for the GUT scale ratios yμ/ys, yτ/yb and yt/yb in particular are shown and compared to experimental data. For this comparison it is important to include possibly large supersymmetric threshold corrections. Due to this reason the structure of the fermion masses at the GUT scale depends on TeV scale physics and makes GUT scale physics testable at the LHC. We also discuss how this new predictions might lead to predictions for mixing angles by discussing the example of the recently measured last missing leptonic mixing angle θ13 making this new class of GUT models also testable in neutrino experiments.

  18. Estimating diversity via frequency ratios.

    PubMed

    Willis, Amy; Bunge, John

    2015-12-01

    We wish to estimate the total number of classes in a population based on sample counts, especially in the presence of high latent diversity. Drawing on probability theory that characterizes distributions on the integers by ratios of consecutive probabilities, we construct a nonlinear regression model for the ratios of consecutive frequency counts. This allows us to predict the unobserved count and hence estimate the total diversity. We believe that this is the first approach to depart from the classical mixed Poisson model in this problem. Our method is geometrically intuitive and yields good fits to data with reasonable standard errors. It is especially well-suited to analyzing high diversity datasets derived from next-generation sequencing in microbial ecology. We demonstrate the method's performance in this context and via simulation, and we present a dataset for which our method outperforms all competitors. PMID:26038228

  19. Sex ratios in bumble bees

    PubMed Central

    Bourke, A. F. G.

    1997-01-01

    The median proportion of investment in females among 11 populations of seven bumble bee (Bombus) species was 0.32 (range 0.07 to 0.64). By contrast, two species of workerless social parasites in the related genus Psithyrus had female-biased sex allocation, the reasons for which remain unclear. Male-biased sex allocation in Bombus contradicts the predictions of Trivers and Hare's sex ratio model for the social Hymenoptera, which are that the population sex investment ratio should be 0.5 (1:1) under queen control and 0.75 (3:1 females:males) under worker control (assuming single, once-mated, outbred queens and non-reproductive workers). Male bias in Bombus does not appear to be either an artefact, or purely the result of symbiotic sex ratio distorters. According to modifications of the TriversHare model, the level of worker male-production in Bombus is insufficient to account for observed levels of male bias. There is also no evidence that male bias arises from either local resource competition (related females compete for resources) or local mate enhancement (related males cooperate in securing mates). Bulmer presented models predicting sexual selection for protandry (males are produced before females) in annual social Hymenoptera and, as a consequence (given some parameter values), male-biased sex allocation. Bumble bees fit the assumptions of Bulmer's models and are protandrous. These models therefore represent the best current explanation for the bees' male-biased sex investment ratios. This conclusion suggests that the relative timing of the production of the sexes strongly influences sex allocation in the social Hymenoptera.

  20. Prolactin/cortisol ratio in rheumatoid arthritis.

    PubMed

    Zoli, Angelo; Ferlisi, Ester Maria; Lizzio, Marco; Altomonte, Lorenzo; Mirone, Luisa; Barini, Angela; Scuderi, Flavia; Bartolozzi, F; Magaro, Mario

    2002-06-01

    Prolactin (PRL) and glucocorticoids are hormones involved in the regulation of the immune system. Rheumatoid arthritis (RA) is an inflammatory condition that presents a diurnal rhythm of disease activity. PRL/cortisol ratio, and IL-1beta and TNF-alpha levels were determined in patients with RA and in control subjects at 0600, 1000, 1400, 1800, 2200, and 0200 hours. In patients with RA we observed higher PRL/cortisol ratio at 0200 hours, whereas IL-1beta and TNF-alpha reached their highest serum levels at 0200 and 0600 hours. In patients with RA we observed an imbalance in favor of proinflammatory hormones as opposed to levels of antiinflammatory hormones during nocturnal hours together with increased levels of IL-1beta and TNF-alpha of the diurnal rhythm of disease activity. PMID:12114312

  1. Envera Variable Compression Ratio Engine

    SciTech Connect

    Charles Mendler

    2011-03-15

    Aggressive engine downsizing, variable compression ratio and use of the Atkinson cycle are being combined to improve fuel economy by up to 40 percent relative to port fuel injected gasoline engines, while maintaining full engine power. Approach Engine downsizing is viewed by US and foreign automobile manufacturers as one of the best options for improving fuel economy. While this strategy has already demonstrated a degree of success, downsizing and fuel economy gains are currently limited. With new variable compression ratio technology however, the degree of engine downsizing and fuel economy improvement can be greatly increased. A small variable compression ratio (VCR) engine has the potential to return significantly higher vehicle fuel economy while also providing high power. Affordability and potential for near term commercialization are key attributes of the Envera VCR engine. VCR Technology To meet torque and power requirements, a smaller engine needs to do more work per stroke. This is typically accomplished by boosting the incoming charge with either a turbo or supercharger so that more energy is present in the cylinder per stroke to do the work. With current production engines the degree of engine boosting (which correlates to downsizing) is limited by detonation (combustion knock) at high boost levels. Additionally, the turbo or supercharger needs to be responsive and efficient while providing the needed boost. VCR technology eliminates the limitation of engine knock at high load levels by reducing compression ratio to {approx}9:1 (or whatever level is appropriate) when high boost pressures are needed. By reducing the compression ratio during high load demand periods there is increased volume in the cylinder at top dead center (TDC) which allows more charge (or energy) to be present in the cylinder without increasing the peak pressure. Cylinder pressure is thus kept below the level at which the engine would begin to knock. When loads on the engine are low the compression ratio can be raised (to as much as 18:1) providing high engine efficiency. It is important to recognize that for a well designed VCR engine cylinder pressure does not need to be higher than found in current production turbocharged engines. As such, there is no need for a stronger crankcase, bearings and other load bearing parts within the VCR engine. The Envera VCR mechanism uses an eccentric carrier approach to adjust engine compression ratio. The crankshaft main bearings are mounted in this eccentric carrier or 'crankshaft cradle' and pivoting the eccentric carrier 30 degrees adjusts compression ratio from 9:1 to 18:1. The eccentric carrier is made up of a casting that provides rigid support for the main bearings, and removable upper bearing caps. Oil feed to the main bearings transits through the bearing cap fastener sockets. The eccentric carrier design was chosen for its low cost and rigid support of the main bearings. A control shaft and connecting links are used to pivot the eccentric carrier. The control shaft mechanism features compression ratio lock-up at minimum and maximum compression ratio settings. The control shaft method of pivoting the eccentric carrier was selected due to its lock-up capability. The control shaft can be rotated by a hydraulic actuator or an electric motor. The engine shown in Figures 3 and 4 has a hydraulic actuator that was developed under the current program. In-line 4-cylinder engines are significantly less expensive than V engines because an entire cylinder head can be eliminated. The cost savings from eliminating cylinders and an entire cylinder head will notably offset the added cost of the VCR and supercharging. Replacing V6 and V8 engines with in-line VCR 4-cylinder engines will provide high fuel economy at low cost. Numerous enabling technologies exist which have the potential to increase engine efficiency. The greatest efficiency gains are realized when the right combination of advanced and new technologies are packaged together to provide the greatest gains at the least cost. Aggressive engine downsizing with variable compression ratio and use of the extended Atkinson cycle can provide large fuel economy gains that are exceptionally cost effective. Analysis indicates that a 2.2L supercharged Envera VCR engine can match the torque of a larger V8 engine at 2000 rpm. The VCR engine's high torque value at low engine speed is beneficial for maintaining the driving feel and responsiveness of the larger V8 engine. The Envera VCR engine will attain high efficiency at {approx}100 Nm primarily due to the combination of engine down-sizing and use of the Atkinson cycle. Qualitatively the fuel economy gain realized from down-sizing from a V8 to an Atkinson-cycle I-4 is about twice as large as the benefits from down-sizing from a V8 to a Turbo V6 when evaluated at 100 Nm 2000 rpm.

  2. Using Ratio Analysis to Evaluate Financial Performance.

    ERIC Educational Resources Information Center

    Minter, John; And Others

    1982-01-01

    The ways in which ratio analysis can help in long-range planning, budgeting, and asset management to strengthen financial performance and help avoid financial difficulties are explained. Types of ratios considered include balance sheet ratios, net operating ratios, and contribution and demand ratios. (MSE)

  3. Low conversion ratio fuel studies.

    SciTech Connect

    Smith, M. A.

    2006-02-28

    Recent studies on TRU disposition in fast reactors indicated viable reactor performance for a sodium cooled low conversion ratio reactor design. Additional studies have been initiated to refine the earlier work and consider the feasibility of alternate fuel forms such as nitride and oxide fuel (rather than metal fuel). These alternate fuel forms may have significant impacts upon the burner design and the safety behavior. The work performed thus far has focused on compiling the necessary fuel form property information and refinement of the physics models. For this limited project, the burner design and performance using nitride fuel will be assessed.

  4. High-aspect-ratio wings

    NASA Technical Reports Server (NTRS)

    Peterson, John B., Jr.

    1988-01-01

    High-aspect-ratio aircraft include most transport aircraft such as commercial and military transports, business aircraft, and cargo aircraft. Generally, these types of aircraft are designed to cruise over a narrow range of lift coefficients and Mach numbers in the performance of their mission. Emphasis is therefore placed on the cruise performance of transport aircraft and every effort is made to obtain accurate wind-tunnel data to use as a basis for prediction of full-scale cruise performance. However, off-cruise performance is also important and methods were developed for extrapolating wind-tunnel data on buffet and flutter at transonic speed. Transport-type aircraft were tested extensively in various wind tunnels around the world and many different test techniques were developed to simulate higher Reynolds numbers. Methods developed for one tunnel may not be applicable to another tunnel because of differences in size, Reynolds number capability, running time, and test objectives. Many of the methods of boundary-layer control developed in two-dimensional airfoil testing can be applied in tests of transport configurations, but sometimes the three-dimensional flow fields that develop on tranpsort aircraft can make application of the two-dimensional methods difficult or impossible. The discussion is intended to be a representative, but not exhaustive, survey of the various methods of high Reynolds number simulation in the testing of high-aspect-ratio aircraft.

  5. Activity ratios of thorium daughters in vivo

    SciTech Connect

    Toohey, R.E.; Rundo, J.; Sha, J.Y.; Essling, M.A.; Pedersen, J.C.; Slane, J.M.

    1984-01-01

    A computerized method of least squares has been used to analyze the /sup 228/Ac and /sup 212/Pb-/sup 212/Bi and daughter ..gamma..-ray spectra obtained in vivo from 133 former workers at a thorium refinery. In addition, the exhalation rate of /sup 220/Rn was determined for each subject and expressed as pCi of emanating /sup 224/Ra. This value was added to the /sup 212/Pb value determined from the ..gamma..-ray measurements to obtain the total /sup 224/Ra present, and the ratio of /sup 224/Ra to /sup 228/Ac was calculated. Values of the ratio ranged from 0.52 +- 0.32 to 2.1 +- 1.7, with a weighted mean of 0.92 +- 0.17. However, it appears that the ratio observed in a given case is characteristic for that case alone; the computed mean value may not be meaningful. The least squares fitting procedure and the overall calibration of the counting system were validated by measurements of /sup 224/Ra in the lungs of one subject postmortem, compared with results obtained from the same subject in vivo. 6 references, 5 figures.

  6. Sex-ratio distortion driven by migration loads.

    PubMed

    Hu, Xin-Sheng; Yeh, Francis C; He, Fangliang

    2007-12-01

    The significance of migration load in driving the evolution of recipient populations has long been documented in population genetics, but its effects have not been linked to the formation of biased sex ratios in natural populations. In this study, we develop a single-locus model to demonstrate how the migration load can shape the primary and secondary sex ratios in dioecious plants where sexual dimorphism is determined by the sex chromosomes (the XX-XY or similar systems). Our results show that migration load can generate an array of sex ratios (from the female- to male-biased primary/secondary sex ratios), depending on the selection systems at the gametophyte and sporophyte stages and on the sex ratio in the migrating seeds. Ovule abortion and the purging of maladaptive genes from the immigrating pollen at the gametophyte stage can alter the primary sex ratio and indirectly alter the secondary sex ratio. The presence of maladaptive sex-linked genes from the migrating pollen and seeds of males facilitates the outcome of the female-biased secondary sex ratios, while the presence of maladaptive sex-linked genes from the migrating seeds of females can lead to the male-biased secondary sex ratios. The detrimental effects of the Y-chromosome from the migrating pollen and seeds can enhance the formation of female-biased primary and secondary sex ratios. These theoretical predictions highlight an alternative approach to the existing sex-ratio theories for interpreting the formation of biased sex ratios in the populations that are subject to the impacts of maladaptive genes from immigrants. PMID:17905398

  7. Variable ratio regenerative braking device

    DOEpatents

    Hoppie, Lyle O. (Birmingham, MI)

    1981-12-15

    Disclosed is a regenerative braking device (10) for an automotive vehicle. The device includes an energy storage assembly (12) having a plurality of rubber rollers (26, 28) mounted for rotation between an input shaft (36) and an output shaft (42), clutches (38, 46) and brakes (40, 48) associated with each shaft, and a continuously variable transmission (22) connectable to a vehicle drivetrain and to the input and output shafts by the respective clutches. The rubber rollers are torsionally stressed to accumulate energy from the vehicle when the input shaft is clutched to the transmission while the brake on the output shaft is applied, and are torsionally relaxed to deliver energy to the vehicle when the output shaft is clutched to the transmission while the brake on the input shaft is applied. The transmission ratio is varied to control the rate of energy accumulation and delivery for a given rotational speed of the vehicle drivetrain.

  8. Skylab S-192 ratio codes of soil, mineral, and rock spectra for ratio image selection and interpretation

    NASA Technical Reports Server (NTRS)

    Vincent, R. K.; Pillars, W. W.

    1974-01-01

    A limited theoretical systems study is made of the Skylab S-192 12-channel multispectral scanner's capabilities for geological remote sensing. Laboratory spectra of rocks, minerals, soils, and some vegetation were used to rank the twelve channels and the best twelve of the 66 possible nonreciprocal spectral ratios according to their ability to discriminate among 17 classes of geological targets. Environmental and instrumental noise sources were ignored. The S-192 should be most useful for discriminating minerals deposited by hydrothermal alteration, weathering, and evaporation. Discrimination of igneous rocks will be difficult. Ratio images are recommended over automatic discrimination methods for those geological targets that can be enhanced by ratio imaging. Ratio codes were found for the twelve highest ranked ratios, for use in selecting the ratio images which will best enhance a target of interest. They can also be searched for false alarm candidates for a given target.

  9. Stereoscopic pyrometer for char combustion characterization.

    PubMed

    Schiemann, M; Vorobiev, N; Scherer, V

    2015-02-10

    For many pulverized fuels, especially coal and biomass, char combustion is the time determining step. Based on intensified ICCD cameras, a novel setup has been developed to study pulverized fuel combustion, mainly in a laminar flow reactor. For char burning characterization, the typical measurement parameters are particle temperature, size, and velocity. The working principle of the camera setup is introduced and its capabilities are discussed by examination of coal particle combustion under CO(2)-enriched, so-called oxy-fuel atmospheres with varying O(2) content. PMID:25968027

  10. Material flows generated by pyromet copper smelting

    USGS Publications Warehouse

    Goonan, T.G.

    2005-01-01

    Copper production through smelting generates large volumes of material flows. As copper contained in ore becomes copper contained in concentrate to be fed into the smelting process, it leaves behind an altered landscape, sometimes mine waste, and always mill tailings. Copper concentrate, fluxing materials, fuels, oxygen, recyclables, scrap and water are inputs to the process. Dust (recycled), gases - containing carbon dioxide (CO2) (dissipated) and sulfur dioxide (SO2) (mostly collected, transformed and sold) and slag (discarded or sold) - are among the significant process outputs. This article reports estimates of the flows of these input/output materials for a particular set of smelters studied in some countries.

  11. In-line process control for laser welding of titanium by high dynamic range ratio pyrometry and plasma spectroscopy

    NASA Astrophysics Data System (ADS)

    Lempe, B.; Taudt, C.; Baselt, T.; Rudek, F.; Maschke, R.; Basan, F.; Hartmann, P.

    2014-02-01

    The production of complex titanium components for various industries using laser welding processes has received growing attention in recent years. It is important to know whether the result of the cohesive joint meets the quality requirements of standardization and ultimately the customer requirements. Erroneous weld seams can have fatal consequences especially in the field of car manufacturing and medicine technology. To meet these requirements, a real-time process control system has been developed which determines the welding quality through a locally resolved temperature profile. By analyzing the resulting weld plasma received data is used to verify the stability of the laser welding process. The determination of the temperature profile is done by the detection of the emitted electromagnetic radiation from the material in a range of 500 nm to 1100 nm. As detectors, special high dynamic range CMOS cameras are used. As the emissivity of titanium depends on the wavelength, the surface and the angle of radiation, measuring the temperature is a problem. To solve these a special pyrometer setting with two cameras is used. That enables the compensation of these effects by calculating the difference between the respective pixels on simultaneously recorded images. Two spectral regions with the same emissivity are detected. Therefore the degree of emission and surface effects are compensated and canceled out of the calculation. Using the spatially resolved temperature distribution the weld geometry can be determined and the laser process can be controlled. The active readjustment of parameters such as laser power, feed rate and inert gas injection increases the quality of the welding process and decreases the number of defective goods.

  12. People Patterns: Ratio. Environmental Module for Use in a Mathematics Laboratory Setting.

    ERIC Educational Resources Information Center

    Trojan, Arthur; Zastrocky, Mike

    The objectives of this module include students being able to: measure using the metric system, determine ratios of different types, and analyze a problem using ratios. Some of the worksheets require the development of ratios from physical activity; others require the development and analysis of ratios using parts of the student's own body.…

  13. People Patterns: Ratio. Environmental Module for Use in a Mathematics Laboratory Setting.

    ERIC Educational Resources Information Center

    Trojan, Arthur; Zastrocky, Mike

    The objectives of this module include students being able to: measure using the metric system, determine ratios of different types, and analyze a problem using ratios. Some of the worksheets require the development of ratios from physical activity; others require the development and analysis of ratios using parts of the student's own body.

  14. Noise of Embedded High Aspect Ratio Nozzles

    NASA Technical Reports Server (NTRS)

    Bridges, James E.

    2011-01-01

    A family of high aspect ratio nozzles were designed to provide a parametric database of canonical embedded propulsion concepts. Nozzle throat geometries with aspect ratios of 2:1, 4:1, and 8:1 were chosen, all with convergent nozzle areas. The transition from the typical round duct to the rectangular nozzle was designed very carefully to produce a flow at the nozzle exit that was uniform and free from swirl. Once the basic rectangular nozzles were designed, external features common to embedded propulsion systems were added: extended lower lip (a.k.a. bevel, aft deck), differing sidewalls, and chevrons. For the latter detailed Reynolds-averaged Navier-Stokes (RANS) computational fluid dynamics (CFD) simulations were made to predict the thrust performance and to optimize parameters such as bevel length, and chevron penetration and azimuthal curvature. Seventeen of these nozzles were fabricated at a scale providing a 2.13 inch diameter equivalent area throat." ! The seventeen nozzles were tested for far-field noise and a few data were presented here on the effect of aspect ratio, bevel length, and chevron count and penetration. The sound field of the 2:1 aspect ratio rectangular jet was very nearly axisymmetric, but the 4:1 and 8:1 were not, the noise on their minor axes being louder than the major axes. Adding bevel length increased the noise of these nozzles, especially on their minor axes, both toward the long and short sides of the beveled nozzle. Chevrons were only added to the 2:1 rectangular jet. Adding 4 chevrons per wide side produced some decrease at aft angles, but increased the high frequency noise at right angles to the jet flow. This trend increased with increasing chevron penetration. Doubling the number of chevrons while maintaining their penetration decreased these effects. Empirical models of the parametric effect of these nozzles were constructed and quantify the trends stated above." Because it is the objective of the Supersonics Project that future design work be done more by physics-based computations and less by experiments, several codes under development were evaluated against these test cases. Preliminary results show that the RANS-based code JeNo predicts the spectral directivity of the low aspect ratio jets well, but has no capability to predict the non-axisymmetry. An effort to address this limitations, used in the RANS-based code of Leib and Goldstein, overpredicted the impact of aspect ratio. The broadband shock noise code RISN, also limited to axisymmetric assumptions, did a good job of predicting the spectral directivity of underexpanded 2:1 cold jet case but was not as successful on high aspect ratio jets, particularly when they are hot. All results are preliminary because the underlying CFD has not been validated yet. An effort using a Large Eddy Simulation code by Stanford University predicted noise that agreed with experiments to within a few dB.

  15. Effect of aspect ratio on heat transfer in shallow enclosures

    NASA Astrophysics Data System (ADS)

    Reddy, C. S.

    1982-06-01

    A mathematical model is developed to simulate the two-dimensional laminar natural convective flow generated in a shallow enclosure due to differential heating of vertical walls. The system of governing equations is numerically solved using the finite differencing techniques and Fourier analysis-cyclic reduction and alternating direction implicit methods. The stream function, vorticity and temperature contour maps are produced to visualize the flow development and thermal behavior for different aspect ratios and Rayleigh numbers. The effect of the enclosure aspect ratio on the heat transfer is investigated for various Rayleigh numbers and a few enclosure orientations. It is found that the Nusselt number is strongly dependent on the aspect ratio, especially for AR less than about 0.5, unlike the case of convection in high aspect ratio enclosures where the Nusselt number is a very weak function of the aspect ratio.

  16. Measurement of fatigue crack closure for negative stress ratio

    SciTech Connect

    Romeiro, F.F.J.; Domingos, C.A.; Freitas, M.J.M. de

    1999-07-01

    The concept of fatigue crack closure, introduced in the 60's by Elber, has been used to explain a wide range of positive stress ratio crack propagation results (R {ge} 0). Less attention has been given to fatigue loading for negative stress ratios (R {lt} 0). In this work the results of crack propagation tests of middle-crack tension M(T) specimens of a normalized medium carbon steel DIN Ck 45 for a wide range of stress ratios from 0.7 {ge} R {ge} {minus}3 are presented. Crack closure loads were measured with the compliance technique at test frequency, using a data acquisition system. Negative crack closure loads were found for negative stress ratios R {le} {minus}1, which can explain higher crack propagation rates and accelerations in crack growth during variable-amplitude tests where compressive loads of different stress ratios are present.

  17. The C-12/C-13 Ratio as a Chemistry Indicator

    NASA Technical Reports Server (NTRS)

    Wirstroem, Eva; Geppert, Wolf; Persson, Carina; Charnley, Steven

    2011-01-01

    Isotopic ratios of elements are considered powerful tools, e.g. in tracing the origin of solar system body materials, or the degree of nucleosynthesis processing throughout the Galaxy. In interstellar molecules, some isotopic ratios like H/D and C-12/C-13 can also be used as indicators of their chemical origin. Isotope fractionation in gas-phase chemical reactions and gas-dust interaction makes observations of the ratio between C-12 and C-13 isotopologues suitable to distinguish between different formation scenarios. We will present observations of the C-12/C-13 ratio in methanol and formaldehyde towards a sample of embedded, massive young stellar objects. In relation to this we also present results from theoretical modeling showing the usefulness of the C-12/C-13 ratio as a chemistry indicator.

  18. C/O ratios in extrasolar planetesimals

    NASA Astrophysics Data System (ADS)

    Wilson, David John; Gaensicke, Boris; Farihi, Jay; Koester, Detlev

    2015-12-01

    The wide range of densities found in small exoplanets imply a variety of possible compositions and interior structures. In particular, some models predict that protoplanetary discs with C/O>0.8 may form carbon-dominated planets. The only way to directly test such predictions are studies of evolved planetary systems at white dwarfs. Analysis of planetesimal debris in white dwarf atmospheres provides a unique insight into the chemical compositions of extrasolar planets, which cannot be observed at main-sequence systems. Thus far, such studies have predominantly focused on individual objects. However, the growing sample of abundance studies now allows conclusions to be derived regarding the overall chemical abundances of (solid) exoplanet precursors in a statistically significant sample of systems. Here, we present measurements of the C/O ratio in the debris of planetesimals at 16 white dwarfs observed with the Hubble Space Telescope. These data allow us to constrain the occurrence frequency of carbon-dominated planets. We find no evidence for such carbon planets, with C/O<0.8 by number in all 16 systems.

  19. High aspect ratio silicon etch: A review

    NASA Astrophysics Data System (ADS)

    Wu, Banqiu; Kumar, Ajay; Pamarthy, Sharma

    2010-09-01

    High aspect ratio (HAR) silicon etch is reviewed, including commonly used terms, history, main applications, different technological methods, critical challenges, and main theories of the technologies. Chronologically, HAR silicon etch has been conducted using wet etch in solution, reactive ion etch (RIE) in low density plasma, single-step etch at cryogenic conditions in inductively coupled plasma (ICP) combined with RIE, time-multiplexed deep silicon etch in ICP-RIE configuration reactor, and single-step etch in high density plasma at room or near room temperature. Key specifications are HAR, high etch rate, good trench sidewall profile with smooth surface, low aspect ratio dependent etch, and low etch loading effects. Till now, time-multiplexed etch process is a popular industrial practice but the intrinsic scalloped profile of a time-multiplexed etch process, resulting from alternating between passivation and etch, poses a challenge. Previously, HAR silicon etch was an application associated primarily with microelectromechanical systems. In recent years, through-silicon-via (TSV) etch applications for three-dimensional integrated circuit stacking technology has spurred research and development of this enabling technology. This potential large scale application requires HAR etch with high and stable throughput, controllable profile and surface properties, and low costs.

  20. Implications of the Nitrogen Isotope Ratio in Titan's Atmosphere for the Nitrogen Ratio in Ammonia in Comets

    NASA Astrophysics Data System (ADS)

    Mandt, K.; Mousis, O.

    2013-12-01

    The D/H ratio of water measured in solar system bodies has been established as a tool for determining the conditions under which bodies such as comets or icy moons formed. This ratio varies significantly and indicates complex thermal and chemical evolution of the solar nebula during solar system and planetary formation. Nitrogen isotope ratios also vary significantly, and in some but not all cases correlate to D/H ratios, but are poorly understood. Nitrogen in the solar nebula was primarily in the form of atomic and molecular nitrogen. The isotope ratio (14N/15N) of this reservoir is expected to be ~435 based on the ratio measured in Jupiter's atmosphere, because the atmosphere of Jupiter is made up of gas captured from the solar nebula (Owen et al., 2001). The terrestrial atmospheric ratio is 272, which is close to the ratio measured in the Earth's mantle. This may be the primordial ratio for nitrogen delivered to Earth depending on the amount of exchange between the atmosphere and the mantle and any atmospheric fractionation processes that may have influenced the ratio over time. Comets are a possible source of nitrogen in the Earth's atmosphere (Hutsmekers et al., 2009), although chondrites have also been suggested as a source (Marty, 2012). In the case of comets, nitrogen would have been essentially retained in the form of ammonia (Mousis et al., 2012), which is the most abundant form of nitrogen in comets. The nitrogen in Titan's atmosphere is expected to have originated as ammonia hydrates and converted to N2 early in Titan's history (Atreya et al., 1978). The nitrogen ratio in Titan's atmosphere is ~170, which is significantly enriched in the heavy isotope compared to the terrestrial value. We will discuss the evolution of the nitrogen ratio in Titan's atmosphere (Mandt et al., 2009), the limits of the primordial ratio in ammonia, and the implications for this ratio for the isotope ratio in ammonia in comets that should be measured by the ROSINA instrument on Rosetta in comet 67P/Churyumov-Gerasimenko (Balsiger et al., 2007). Atreya, S., et al., 1978, Science, 201, 611-613. Balsiger, H., et al., 2007, Space Science Reviews, 128, 745-801. Hutsmekers et al., 2009, Icarus, 204, 346-348. Marty, B., 2012, Earth and Planetary Science Letters, 313-314, 56-66. Mandt, K. E., et al., 2009, Planetary and Space Science, 57, 1917-1930. Mousis, O., et al., 2012, The Astrophysical Journal, 757, 146. Owen, T. et al., 2001, The Astrophysical Journal, 553, L77-L79.

  1. Implications of Fast Reactor Transuranic Conversion Ratio

    SciTech Connect

    Steven J. Piet; Edward A. Hoffman; Samuel E. Bays

    2010-11-01

    Theoretically, the transuranic conversion ratio (CR), i.e. the transuranic production divided by transuranic destruction, in a fast reactor can range from near zero to about 1.9, which is the average neutron yield from Pu239 minus 1. In practice, the possible range will be somewhat less. We have studied the implications of transuranic conversion ratio of 0.0 to 1.7 using the fresh and discharge fuel compositions calculated elsewhere. The corresponding fissile breeding ratio ranges from 0.2 to 1.6. The cases below CR=1 (“burners”) do not have blankets; the cases above CR=1 (“breeders”) have breeding blankets. The burnup was allowed to float while holding the maximum fluence to the cladding constant. We graph the fuel burnup and composition change. As a function of transuranic conversion ratio, we calculate and graph the heat, gamma, and neutron emission of fresh fuel; whether the material is “attractive” for direct weapon use using published criteria; the uranium utilization and rate of consumption of natural uranium; and the long-term radiotoxicity after fuel discharge. For context, other cases and analyses are included, primarily once-through light water reactor (LWR) uranium oxide fuel at 51 MWth-day/kg-iHM burnup (UOX-51). For CR<1, the heat, gamma, and neutron emission increase as material is recycled. The uranium utilization is at or below 1%, just as it is in thermal reactors as both types of reactors require continuing fissile support. For CR>1, heat, gamma, and neutron emission decrease with recycling. The uranium utilization exceeds 1%, especially as all the transuranic elements are recycled. exceeds 1%, especially as all the transuranic elements are recycled. At the system equilibrium, heat and gamma vary by somewhat over an order of magnitude as a function of CR. Isotopes that dominate heat and gamma emission are scattered throughout the actinide chain, so the modest impact of CR is unsurprising. Neutron emitters are preferentially found among the higher actinides, so the neutron emission varies much stronger with CR, about three orders of magnitude.

  2. High/variable mixture ratio O2/H2 engine

    NASA Technical Reports Server (NTRS)

    Adams, A.; Parsley, R. C.

    1988-01-01

    Vehicle/engine analysis studies have identified the High/Dual Mixture Ratio O2/H2 Engine cycle as a leading candidate for an advanced Single Stage to Orbit (SSTO) propulsion system. This cycle is designed to allow operation at a higher than normal O/F ratio of 12 during liftoff and then transition to a more optimum O/F ratio of 6 at altitude. While operation at high mixture ratios lowers specific impulse, the resultant high propellant bulk density and high power density combine to minimize the influence of atmospheric drag and low altitude gravitational forces. Transition to a lower mixture ratio at altitude then provides improved specific impulse relative to a single mixture ratio engine that must select a mixture ratio that is balanced for both low and high altitude operation. This combination of increased altitude specific impulse and high propellant bulk density more than offsets the compromised low altitude performance and results in an overall mission benefit. Two areas of technical concern relative to the execution of this dual mixture ratio cycle concept are addressed. First, actions required to transition from high to low mixture ratio are examined, including an assessment of the main chamber environment as the main chamber mixture ratio passes through stoichiometric. Secondly, two approaches to meet a requirement for high turbine power at high mixture ratio condition are examined. One approach uses high turbine temperature to produce the power and requires cooled turbines. The other approach incorporates an oxidizer-rich preburner to increase turbine work capability via increased turbine mass flow.

  3. Combined measurements of a UV mini MAX-DOAS system and a TX for retrieval of ambient trace gas mixing ratio: Comparisons with combined RTM and MAX-DOAS methods

    NASA Astrophysics Data System (ADS)

    Lee, Hanlim; Ryu, Jaeyong; Kim, Jhoon; Noh, Youngmin; Yoon, Younghun

    2011-12-01

    A measurement method combining multi-axis differential optical absorption spectroscopy (MAX-DOAS) and a transmissometer (TX) is introduced as a means of retrieving surface trace gas mixing ratios in ambient air. The combined measurement method was utilized to derive surface NO 2 mixing ratios from 27 March to 11 May 2007 in Seoul, Korea. To convert the differential slant column density (DSCD) to the volume mixing ratio (VMR), the light path length (LPL) along the MAX-DOAS line of sight was derived using the light extinction coefficient and ngstrom exponent data obtained by a TX and sunphotometer, respectively. Temporal variations of the NO 2 VMRs at the 0-1 km layer obtained from radiative transfer model (RTM) simulations coupled with MAX-DOAS data show similar patterns, but with reduced magnitudes, to the ground level data and those of the combined MAX-DOAS and TX measurements at 0.08 km. The NO 2 VMRs retrieved by the combined measurement were in agreement with those obtained from the RTM simulations coupled with MAX-DOAS data and the in-situ measurements within 40 and 50%, respectively. The coefficient of determination ( R2) of 0.75 was obtained between the combined measurement data sets and those of the RTM simulations coupled with MAX-DOAS data whereas that between the combined measurement data sets and those of the in-situ measurements was 0.53. The coefficient of determination ( R2) between the data sets derived from the RTM simulations coupled with MAX-DOAS data and those of the in-situ measurements was 0.67 with the scatter of the correlation within the 50% range.

  4. A theoretically based determination of bowen-ratio fetch requirements

    USGS Publications Warehouse

    Stannard, D.I.

    1997-01-01

    Determination of fetch requirements for accurate Bowen-ratio measurements of latent- and sensible-heat fluxes is more involved than for eddy-correlation measurements because Bowen-ratio sensors are located at two heights, rather than just one. A simple solution to the diffusion equation is used to derive an expression for Bowen-ratio fetch requirements, downwind of a step change in surface fluxes. These requirements are then compared to eddy-correlation fetch requirements based on the same diffusion equation solution. When the eddy-correlation and upper Bowen-ratio sensor heights are equal, and the available energy upwind and downwind of the step change is constant, the Bowen-ratio method requires less fetch than does eddy correlation. Differences in fetch requirements between the two methods are greatest over relatively smooth surfaces. Bowen-ratio fetch can be reduced significantly by lowering the lower sensor, as well as the upper sensor. The Bowen-ratio fetch model was tested using data from a field experiment where multiple Bowen-ratio systems were deployed simultaneously at various fetches and heights above a field of bermudagrass. Initial comparisons were poor, but improved greatly when the model was modified (and operated numerically) to account for the large roughness of the upwind cotton field.

  5. Toward a Unique Nitrogen Isotopic Ratio in Cometary Ices

    NASA Astrophysics Data System (ADS)

    Rousselot, Philippe; Pirali, Olivier; Jehin, Emmanul; Vervloet, Michel; Hutsemkers, Damien; Manfroid, Jean; Cordier, Daniel; Martin-Drumel, Marie-Aline; Gruet, Sbastien; Arpigny, Claude; Decock, Alice; Mousis, Olivier

    2014-01-01

    Determination of the nitrogen isotopic ratios in different bodies of the solar system provides important information regarding the solar system's origin. We unambiguously identified emission lines in comets due to the 15NH2 radical produced by the photodissociation of 15NH3. Analysis of our data has permitted us to measure the 14N/15N isotopic ratio in comets for a molecule carrying the amine (-NH) functional group. This ratio, within the error, appears similar to that measured in comets in the HCN molecule and the CN radical, and lower than the protosolar value, suggesting that N2 and NH3 result from the separation of nitrogen into two distinct reservoirs in the solar nebula. This ratio also appears similar to that measured in Titan's atmospheric N2, supporting the hypothesis that, if the latter is representative of its primordial value in NH3, these bodies were assembled from building blocks sharing a common formation location.

  6. Elevated Neutrophil Lymphocyte Ratio in Recurrent Optic Neuritis

    PubMed Central

    Guclu, Hande; Ozal, Sad?k Altan; Pelitli Gurlu, Vuslat; Birgul, Ramazan

    2015-01-01

    Purpose. To demonstrate the relation between optic neuritis (ON) and systemic inflammation markers as neutrophil lymphocyte ratio (N/L ratio), platelet count, mean platelet volume (MPV), and red cell distribution width (RDW) and furthermore to evaluate the utilization of these markers to predict the frequency of the ON episodes. Methods. Forty-two patients with acute ON and forty healthy subjects were enrolled into the study. The medical records were reviewed for age, sex, hemoglobin (Hb), Haematocrit (Htc), RDW, platelet count, MPV, white blood cell count (WBC), neutrophil and lymphocyte count, and neutrophil lymphocyte ratio (N/L ratio). Results. The mean N/L ratio, platelet counts, and RDW were significantly higher in ON group (p = 0.000, p = 0.048, and p = 0.002). There was a significant relation between N/L ratio and number of episodes (r = 0.492, p = 0.001). There was a statistically significant difference for MPV between one episode group and recurrent ON group (p = 0.035). Conclusions. Simple and inexpensive laboratory methods could help us show systemic inflammation and monitor ON patients. Higher N/L ratio can be a useful marker for predicting recurrent attacks. PMID:26060578

  7. How required reserve ratio affects distribution and velocity of money

    NASA Astrophysics Data System (ADS)

    Xi, Ning; Ding, Ning; Wang, Yougui

    2005-11-01

    In this paper the dependence of wealth distribution and the velocity of money on the required reserve ratio is examined based on a random transfer model of money and computer simulations. A fractional reserve banking system is introduced to the model where money creation can be achieved by bank loans and the monetary aggregate is determined by the monetary base and the required reserve ratio. It is shown that monetary wealth follows asymmetric Laplace distribution and latency time of money follows exponential distribution. The expression of monetary wealth distribution and that of the velocity of money in terms of the required reserve ratio are presented in a good agreement with simulation results.

  8. Poisson`s ratio and crustal seismology

    SciTech Connect

    Christensen, N.I.

    1996-02-10

    This report discusses the use of Poisson`s ratio to place constraints on continental crustal composition. A summary of Poisson`s ratios for many common rock formations is also included with emphasis on igneous and metamorphic rock properties.

  9. 12 CFR 167.8 - Leverage ratio.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... assigned a composite rating of 1, as defined in 116.3 of this chapter, shall consist of a ratio of core... leverage capital requirement shall consist of a ratio of core capital to adjusted total assets of 4...

  10. 12 CFR 567.8 - Leverage ratio.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... a composite rating of 1, as defined in 516.3 of this chapter, shall consist of a ratio of core... capital requirement shall consist of a ratio of core capital to adjusted total assets of 4 percent....

  11. Variable mixture ratio performance through nitrogen augmentation

    NASA Technical Reports Server (NTRS)

    Beichel, R.; Obrien, C. J.; Bair, E. K.

    1988-01-01

    High/variable mixture ratio O2/H2 candidate engine cycles are examined for earth-to-orbit vehicle application. Engine performance and power balance information are presented for the candidate cycles relative to chamber pressure, bulk density, and mixture ratio. Included in the cycle screening are concepts where a third fluid (liquid nitrogen) is used to achieve a variable mixture ratio over the trajectory from liftoff to earth orbit. The third fluid cycles offer a very low risk, fully reusable, low operation cost alternative to high/variable mixture ratio bipropellant cycles. Variable mixture ratio engines with extendible nozzle are slightly lower performing than a single mixture ratio engine (MR = 7:1) with extendible nozzle. Dual expander engines (MR = 7:1) have slightly better performance than the single mixture ratio engine. Dual fuel dual expander engines offer a 16 percent improvement over the single mixture ratio engine.

  12. Effect of fuel-air-ratio nonuniformity on emissions of nitrogen oxides

    NASA Technical Reports Server (NTRS)

    Lyons, V. J.

    1981-01-01

    The inlet fuel-air ratio nonuniformity is studied to deterine how nitrogen oxide (NOx) emissions are affected. An increase in NOx emissions with increased fuel-air ratio nonuniformity for average equivalence ratios less than 0.7 and a decrease in NOx emissions for average equivalence ratios near stoichiometric is predicted. The degree of uniformityy of fuel-air ratio profiles that is necessary to achieve NOx emissions goals for actual engines that use lean, premixed, prevaporized combustion systems is determined.

  13. 12 CFR 567.8 - Leverage ratio.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Leverage ratio. 567.8 Section 567.8 Banks and... 567.8 Leverage ratio. (a) The minimum leverage capital requirement for a savings association assigned a composite rating of 1, as defined in 516.3 of this chapter, shall consist of a ratio of...

  14. Spray Gun With Constant Mixing Ratio

    NASA Technical Reports Server (NTRS)

    Simpson, William G.

    1987-01-01

    Conceptual mechanism mounted in handle of spray gun maintains constant ratio between volumetric flow rates in two channels leading to spray head. With mechanism, possible to keep flow ratio near 1:1 (or another desired ratio) over range of temperatures, orifice or channel sizes, or clogging conditions.

  15. HEAVY ION FUSION SCIENCE VIRTUAL NATIONAL LABORATORY2nd QUARTER 2010 MILESTONE REPORTDevelop the theory connecting pyrometer and streak camera spectrometer data to the material properties of beam heatedtargets and compare to the data

    SciTech Connect

    More, R.M.; Barnard, J. J.; Bieniosek, F.M.; Henestroza, E.; Lidia, S. M.; Ni, P. A.

    2010-04-01

    This milestone has been accomplished. We have extended the theory that connects pyrometer and streak spectrometer data to material temperature on several fronts and have compared theory to NDCX-I experiments. For the case of NDCX-I, the data suggests that as the metallic foils are heated they break into droplets (cf. HIFS VNL Milestone Report FY 2009 Q4). Evaporation of the metallic surface will occur, but optical emission should be directly observable from the solid or liquid surface of the foil or from droplets. However, the emissivity of hot material may be changed from the cold material and interference effects will alter the spectrum emitted from small droplets. These effects have been incorporated into a theory of emission from droplets. We have measured emission using streaked spectrometry and together with theory of emission from heated droplets have inferred the temperature of a gold foil heated by the NDCX-I experiment. The intensity measured by the spectrometer is proportional to the emissivity times the blackbody intensity at the temperature of the foil or droplets. Traditionally, a functional form for the emissivity as a function of wavelength (such as a quadratic) is assumed and the three unknown emissivity parameters (for the case of a quadratic) and the temperature are obtained by minimizing the deviations from the fit. In the case of the NDCX-I experiment, two minima were obtained: at 7200 K and 2400 K. The best fit was at 7200 K. However, when the actual measured emissivity of gold was used and when the theoretical corrections for droplet interference effects were made for emission from droplets having radii in the range 0.2 to 2.0 microns, the corrected emissivity was consistent with the 2400 K value, whereas the fit emissivity at 7200 K shows no similarity to the corrected emissivity curves. Further, an estimate of the temperature obtained from beam heating is consistent with the lower value. This exercise proved to be a warning to be skeptical of assuming functional forms when they are unknown, and also represents a first success of the droplet emission theory. The thermal optical emission from a hot metal surface is polarized (for observation angles that are not normal to the surface). By observing the intensity of both polarizations at two or more observation angles the emissivity can be inferred directly, and the temperature at the surface unambiguously determined. Emission from the spolarization (where the E-field is parallel to the surface and normal to the wave vector) is generally less intense than emission from the p-polarization (E-field that is normal to the s-polarization E-field and the wave vector.) The emissivity and temperature may be inferred directly without assuming any specific functional form for the emissivity or resorting to published data tables (which usually do not apply when temperatures reach the WDM regime). We have derived the theory of polarized emission from hot metals, and consider an improved method of temperature determination that takes advantage of polarization measurements, which we call polarization pyrometry. Thus far we have successfully applied the theory to electrically heated metallic filaments, and will apply the theory to beam heated targets when chamber space constraints are removed that will make it feasible to observe the targets at multiple angles. For the case of experiments on NDCX-II, hydrodynamic expansion on a nanosecond timescale that is comparable to the heating time will result in an expanding fluid, with a strong (but finite) density and temperature gradient. Emission will be observed from positions in the foil near the critical density (where the observation photon frequency is equal to the local plasma frequency). By assuming a brightness temperature equal to the local fluid temperature at the critical frequency, a time history of the emission spectrum from an expanding foil can be synthesized from a hydrodynamic simulation of the target. We find that observations from the ultraviolet to the infrared will allow a probing of the target at different depths, and will allow a test of specific equations of state. Improved versions of this theory that integrate the electric field along a ray from the interior of the metal to observation point are being constructed to give a more accurate description of the emitted spectrum.

  16. Nondestructive measurement of the grid ratio using a single image

    SciTech Connect

    Pasciak, A. S.; Jones, A. Kyle

    2009-10-15

    The antiscatter grid is an essential part of modern radiographic systems. Since the introduction of the antiscatter grid, however, there have been few methods proposed for acceptance testing and verification of manufacturer-supplied grid specifications. The grid ratio (r) is an important parameter describing the antiscatter grid because it affects many other grid quality metrics, such as the contrast improvement ratio (K), primary transmission (T{sub p}), and scatter transmission (T{sub s}). Also, the grid ratio in large part determines the primary clinical use of the grid. To this end, the authors present a technique for the nondestructive measurement of the grid ratio of antiscatter grids. They derived an equation that can be used to calculate the grid ratio from a single off-focus flat field image by exploiting the relationship between grid cutoff and off-focus distance. The calculation can be performed by hand or with included analysis software. They calculated the grid ratios of several different grids throughout the institution, and afterward they destructively measured the grid ratio of a nominal r8 grid previously evaluated with the method. They also studied the sensitivity of the method to technical factors and choice of parameters. With one exception, the results for the grids found in the institution were in agreement with the manufacturer's specifications and international standards. The nondestructive evaluation of the r8 grid indicated a ratio of 7.3, while the destructive measurement indicated a ratio of 7.53{+-}0.28. Repeated evaluations of the same grid yielded consistent results. The technique provides the medical physicist with a new tool for quantitative evaluation of the grid ratio, an important grid performance criterion. The method is robust and repeatable when appropriate choices of technical factors and other parameters are made.

  17. Parental investment, sexual selection and sex ratios.

    PubMed

    Kokko, Hanna; Jennions, Michael D

    2008-07-01

    Conventional sex roles imply caring females and competitive males. The evolution of sex role divergence is widely attributed to anisogamy initiating a self-reinforcing process. The initial asymmetry in pre-mating parental investment (eggs vs. sperm) is assumed to promote even greater divergence in post-mating parental investment (parental care). But do we really understand the process? Trivers [Sexual Selection and the Descent of Man 1871-1971 (1972), Aldine Press, Chicago] introduced two arguments with a female and male perspective on whether to care for offspring that try to link pre-mating and post-mating investment. Here we review their merits and subsequent theoretical developments. The first argument is that females are more committed than males to providing care because they stand to lose a greater initial investment. This, however, commits the 'Concorde Fallacy' as optimal decisions should depend on future pay-offs not past costs. Although the argument can be rephrased in terms of residual reproductive value when past investment affects future pay-offs, it remains weak. The factors likely to change future pay-offs seem to work against females providing more care than males. The second argument takes the reasonable premise that anisogamy produces a male-biased operational sex ratio (OSR) leading to males competing for mates. Male care is then predicted to be less likely to evolve as it consumes resources that could otherwise be used to increase competitiveness. However, given each offspring has precisely two genetic parents (the Fisher condition), a biased OSR generates frequency-dependent selection, analogous to Fisherian sex ratio selection, that favours increased parental investment by whichever sex faces more intense competition. Sex role divergence is therefore still an evolutionary conundrum. Here we review some possible solutions. Factors that promote conventional sex roles are sexual selection on males (but non-random variance in male mating success must be high to override the Fisher condition), loss of paternity because of female multiple mating or group spawning and patterns of mortality that generate female-biased adult sex ratios (ASR). We present an integrative model that shows how these factors interact to generate sex roles. We emphasize the need to distinguish between the ASR and the operational sex ratio (OSR). If mortality is higher when caring than competing this diminishes the likelihood of sex role divergence because this strongly limits the mating success of the earlier deserting sex. We illustrate this in a model where a change in relative mortality rates while caring and competing generates a shift from a mammalian type breeding system (female-only care, male-biased OSR and female-biased ASR) to an avian type system (biparental care and a male-biased OSR and ASR). PMID:18462318

  18. Transformer ratio improvement for beam based plasma accelerators

    SciTech Connect

    O'Shea, Brendan; Rosenzweig, James; Barber, Samuel; Fukasawa, Atsushi; Williams, Oliver; Muggli, Patric; Yakimenko, Vitaly; Kusche, Karl

    2012-12-21

    Increasing the transformer ratio of wakefield accelerating systems improves the viability of present novel accelerating schemes. The use of asymmetric bunches to improve the transformer ratio of beam based plasma systems has been proposed for some time[1, 2] but suffered from lack appropriate beam creation systems. Recently these impediments have been overcome [3, 4] and the ability now exists to create bunches with current profiles shaped to overcome the symmetric beam limit of R {<=} 2. We present here work towards experiments designed to measure the transformer ratio of such beams, including theoretical models and simulations using VORPAL (a 3D capable PIC code) [5]. Specifically we discuss projects to be carried out in the quasi-nonlinear regime [6] at the UCLA Neptune Laboratory and the Accelerator Test Facility at Brookhaven National Lab.

  19. Ultrahigh-Aspect-Ratio Contact Hole Etching

    NASA Astrophysics Data System (ADS)

    Ikegami, Naokatsu

    1997-10-01

    An ultrasmall, 60nm-diameter, 2um-deep contact hole pattern of BPSG film was successfully fabricated using a poly-Si mask and a magnetically enhanced reactive-ion-etching system. Significantly weaker dependence of etch rate on aspect ratio(AR) was obtained up to AR=30, showing that the energetic ions (and/or neutralized molecules) with a sufficient flux for etching reaction are supplied onto the hole bottom even in such a extremely fine feature. On the other hand, neutral supply of polymer precursors onto the hole bottom (Si substrate) is not sufficient for polymerization in holes with aspect ratios greater than 10, where several energetic particles reach the hole bottoms and contribute to the etching reaction with Si substrates. For features with dimensions below 100nm, processing of vertical profiles is extremely difficult, and problems in the form of bowing at the sidewalls of the holes can occur. The shape of the etched feature and the occurrence of etch stops were shown to be in a trade-off relationship. However, vertical profiles were successfully obtained with diameters greater than 100nm without etch stops. It is possible that ion flux is significantly influenced (reduced) when ions pass through the poly-Si mask, rather than through the BPSG hole. The bowing is associated with bending of the incident ion trajectories, where the first stage of the trajectory change occurs at the mask, and subsequent multiple scattering of ions at the sidewall of the hole can occur. Other factors include sidewall protection by redeposited Si that was sputtered from the poly-Si mask and/or the deposited fluorocarbon polymers, and the effects of ion flux and energy bombarding these deposited materials. In the future, it will be necessary to clarify the details of the mechanisms of these phenomena and to establish technologies to control them. note number.

  20. ESTADIUS: A High Motion "One Arcsec" Daytime Attitude Estimation System for Stratospheric Applications

    NASA Astrophysics Data System (ADS)

    Montel, J.; Andre, Y.; Mirc, F.; Etcheto, P.; Evrard, J.; Bray, N.; Saccoccio, M.; Tomasini, L.; Perot, E.

    2015-09-01

    ESTADIUS is an autonomous, accurate and daytime attitude estimation system, for stratospheric balloons that require a high level of attitude measurement and stability. The system has been developed by CNES. ESTADIUS is based on star sensor an pyrometer data fusion within an extended Kalman filter. The star sensor is composed of a 16 MPixels visible-CCD camera and a large aperture camera lens (focal length of 135mm, aperture f/1.8, 10ºx15º field of view or FOV) which provides very accurate stars measurements due to very low pixel angular size. This also allows detecting stars against a bright sky background. The pyrometer is a 0.01º/h performance class Fiber Optic Gyroscope (FOG). The system is adapted to work down to an altitude of ~25km, even under high cinematic conditions. Key elements of ESTADIUS are: daytime conditions use (as well as night time), autonomy (automatic recognition of constellations), high angular rate robustness (a few deg/s thanks to the high performance of attitude propagation), stray-light robustness (thanks to a high performance baffle), high accuracy (<1", 1σ). Four stratospheric qualification flights were very successfully performed in 2010/2011 and 2013/2014 in Kiruna (Sweden) and Timmins (Canada). ESTADIUS will allow long stratospheric flights with a unique attitude estimation system avoiding the restriction of night/day conditions at launch. The first operational flight of ESTADIUS will be in 2015 for the PILOT scientific missions (led by IRAP and CNES in France). Further balloon missions such as CIDRE will use the system ESTADIUS is probably the first autonomous, large FOV, daytime stellar attitude measurement system. This paper details the technical features and in-flight results.

  1. Quantifying Void Ratio in Granular Materials Using Voronoi Tessellation

    NASA Technical Reports Server (NTRS)

    Alshibli, Khalid A.; El-Saidany, Hany A.; Rose, M. Franklin (Technical Monitor)

    2000-01-01

    Voronoi technique was used to calculate the local void ratio distribution of granular materials. It was implemented in an application-oriented image processing and analysis algorithm capable of extracting object edges, separating adjacent particles, obtaining the centroid of each particle, generating Voronoi polygons, and calculating the local void ratio. Details of the algorithm capabilities and features are presented. Verification calculations included performing manual digitization of synthetic images using Oda's method and Voronoi polygon system. The developed algorithm yielded very accurate measurements of the local void ratio distribution. Voronoi tessellation has the advantage, compared to Oda's method, of offering a well-defined polygon generation criterion that can be implemented in an algorithm to automatically calculate local void ratio of particulate materials.

  2. Diffusive Transport Analysis in Low Aspect Ratio Reversed Field Pinch

    NASA Astrophysics Data System (ADS)

    Nagamine, Yasuo; Fukuyama, Atsushi; Shiina, Shoichi; Aizawa, Masamitsu

    2014-05-01

    For the evaluation of confinement property of a low aspect ratio reversed field pinch (RFP) plasma, diffusive transport analysis is studied. Numerical analysis based on the neoclassical transport model in a low aspect ratio RFP show that a considerable bootstrap current contibution can be expected in this configuration, when incorporating the effects of non-circular cross-section and low aspect ratio. So-called neclassical RFP equilibrium are also found to attain both high stablity beta limit and high bootstrap current fraction. However, of transport phenomena in an RFP, the energy confinement time ?E might be determined by anomalous transport due to micro-instabilities. To analyze such transport phenomena in a low aspect ratio RFP, the applicability of the TASK (Transport Analysing System for TokamaK) simulation code are considered.

  3. Poisson's ratio in layered two-dimensional crystals

    NASA Astrophysics Data System (ADS)

    Woo, Sungjong; Park, Hee Chul; Son, Young-Woo

    2016-02-01

    We present first-principles calculations of elastic properties of multilayered two-dimensional crystals, such as graphene, h -BN, and 2 H -MoS2 , which show that their Poisson's ratios along the out-of-plane direction are negative, near zero, and positive, respectively, spanning all possibilities for the sign of the ratios. While the in-plane Poisson's ratios are all positive regardless of their disparate electronic and structural properties, the characteristic interlayer interactions as well as layer stacking structures are shown to determine the sign of their out-of-plane ratios. A thorough investigation of elastic properties as a function of the number of layers for each system is also provided, highlighting their intertwined nature between elastic and electronic properties.

  4. Liquidus Temperatures of Cryolite Melts With Low Cryolite Ratio

    NASA Astrophysics Data System (ADS)

    Apisarov, Alexei; Dedyukhin, Alexander; Nikolaeva, Elena; Tinghaev, Pavel; Tkacheva, Olga; Redkin, Alexander; Zaikov, Yurii

    2011-02-01

    The effect of calcium fluoride on liquidus temperatures of the cryolite melts with a low cryolite ratio (CR) was studied. The systems KF-NaF-AlF3 and KF-LiF-AlF3 with CRs of 1.3, 1.5, and 1.7 have been investigated. The liquidus curves of systems containing CaF2 are different and depend on the K/(K + Na) and K/(K + Li) ratios. In potassium cryolite with CRs of 1.3 and 1.5, the calcium fluoride solubility is low and increases with NaF (LiF) concentration.

  5. Eccentric crank variable compression ratio mechanism

    DOEpatents

    Lawrence, Keith Edward (Kobe, JP); Moser, William Elliott (Peoria, IL); Roozenboom, Stephan Donald (Washington, IL); Knox, Kevin Jay (Peoria, IL)

    2008-05-13

    A variable compression ratio mechanism for an internal combustion engine that has an engine block and a crankshaft is disclosed. The variable compression ratio mechanism has a plurality of eccentric disks configured to support the crankshaft. Each of the plurality of eccentric disks has at least one cylindrical portion annularly surrounded by the engine block. The variable compression ratio mechanism also has at least one actuator configured to rotate the plurality of eccentric disks.

  6. Sex ratio at birth in Croatia: update.

    PubMed

    Pavi?, Dario

    2014-06-01

    There is strong evidence that the sex ratio at birth is partially determined by environmental and social factors. The modern change in those factors serves as an explanation for the secular decline in sex ratio at birth in most of the industrialized countries. This article is the reexamination of the results from my previous communication in which no trend in sex ratio at birth was established for the Croatian data from 1946 to 2007. The data for the years 2008 to 2011 were added, which didn't result with the detection of a significant change in sex ratio at birth by the regression analysis or by the Box-Jenkins time series analysis. Although the numerous factors associated with the decline in sex ratio at birth did occur during the studied period (e.g. increased exposure to the environmental pollution through food, air and water, the rise of the obesity and diabetes incidence, the economic crisis etc.), it appears that none of them made the measurable impact on sex ratio at birth. Also, the possible marginally significant decline in sex ratio at birth could be the result of a high sex ratio at birth immediately after the World War II. The results of this study caution against rapid generalization of the factors found to influence the sex ratio at birth in the epidemiological and clinical studies on the population level data. PMID:25144988

  7. Force dynamics in fixed-ratio schedules.

    PubMed

    Pinkston, Jonathan W; McBee, Lindsey N

    2014-03-01

    Fixed-ratio schedules are widely used in behavioral research. Although fixed-ratio schedules often conjure up relationships to work and effort, little is known about effort-related measures in these schedules. Early research had shown that force and effort of operant behavior vary systematically during the execution of ratio schedules, and the goal of the present study was to revisit early research on force dynamics in fixed-ratio schedules. Four rats earned sucrose by pressing an isometric force transducer. Presses produced sucrose after ten or twenty responses. In general, the force of responses increased then decreased systematically across the ratio. The possibility that decreases in force during ratio execution was due to a trade-off with the differential reinforcement of short inter-response times (IRT) was investigated in an additional condition where sucrose was made available according to a tandem fixed-ratio 19 inter-response (IRT)> t schedule. The tandem IRT requirement did not eliminate decreasing trends in force across the ratio; unexpectedly, the tandem requirement did eliminate increases in force early in the ratio, which may reflect sequence-level organization operating in the control of force dynamics. PMID:24315798

  8. 7 CFR 400.162 - Qualification ratios.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., DEPARTMENT OF AGRICULTURE GENERAL ADMINISTRATIVE REGULATIONS Reinsurance Agreement-Standards for Approval; Regulations for the 1997 and Subsequent Reinsurance Years § 400.162 Qualification ratios. The...

  9. Low concentration ratio solar array structural configuration

    NASA Technical Reports Server (NTRS)

    Nalbandian, S. J.

    1984-01-01

    The design and structural properties of a low concentration ratio solar array are discussed. The assembled module consists of six interconnected containers which are compactly stowed in a volume of 3.24 m(3) for delivery to orbit by the shuttle. The containers deploy in accordian fashion into a rectangular area of 19.4 x 68 meters and can be attached to the user spacecraft along the longitudinal centerline of the end container housing. Five rotary incremental actuators requiring about 8 watts each will execute the 180-degree rotation at each joint. Deployable masts (three per side) are used to extend endcaps from the housing in both directions. Each direction is extended by three masts requiring about 780 watts for about 27 minutes. Concentrator elements are extended by the endcaps and are supported by cable systems that are connected between the housings and endcaps. These power generating elements contain reflector panels which concentrate light onto the solar panels consisting of an aluminum radiator with solar cells positioned within the element base formed by the reflectors. A flat wire harness collects the power output of individual elements for transfer to the module container housing harnesses.

  10. Should sex-ratio distorting parasites abandon horizontal transmission?

    PubMed Central

    2011-01-01

    Background Sex-ratio distorting parasites are of interest due to their effects upon host population dynamics and their potential to influence the evolution of host sex determination systems. In theory, the ability to distort host sex-ratios allows a parasite with efficient vertical (hereditary) transmission to dispense completely with horizontal (infectious) transmission. However, recent empirical studies indicate that some sex-ratio distorting parasites have retained the capability for horizontal transmission. Results Numerical simulations using biologically realistic parameters suggest that a feminising parasite is only likely to lose the capability for horizontal transmission if its host occurs at low density and/or has a male-biased primary sex ratio. It is also demonstrated that even a small amount of horizontal transmission can allow multiple feminising parasites to coexist within a single host population. Finally it is shown that, by boosting its host's rate of population growth, a feminising parasite can increase its own horizontal transmission and allow the invasion of other, more virulent parasites. Conclusions The prediction that sex-ratio distorting parasites are likely to retain a degree of horizontal transmission has important implications for the epidemiology and host-parasite interactions of these organisms. It may also explain the frequent co-occurrence of several sex-ratio distorting parasite species in nature. PMID:22188680

  11. Ecological genetics of sex ratios in plant populations.

    PubMed

    Barrett, Spencer C H; Yakimowski, Sarah B; Field, David L; Pickup, Melinda

    2010-08-27

    In many angiosperm species, populations are reproductively subdivided into distinct sexual morphs including females, males and hermaphrodites. Sexual polymorphism is maintained by frequency-dependent selection, leading to predictable sex ratios at equilibrium. Charles Darwin devoted much of his book 'The Different Forms of Flowers on Plants of the Same Species' (1877) to investigating plant sexual polymorphisms and laid the foundation for many problems addressed today by integrating theory with empirical studies of the demography and genetics of populations. Here, we summarize our recent work on the ecological and genetic mechanisms influencing variation in sex ratios and their implications for evolutionary transitions among sexual systems. We present the results of a survey of sex ratios from 126 species from 47 angiosperm families and then address two general problems using examples from diverse angiosperm taxa: (i) the mechanisms governing biased sex ratios in dioecious species; (ii) the origins and maintenance of populations composed of females, males and hermaphrodites. Several themes are emphasized, including the importance of non-equilibrium conditions, the role of life history and demography in affecting sex ratios, the value of theory for modelling the dynamics of sex ratio variation, and the utility of genetic markers for investigating evolutionary processes in sexually polymorphic plant populations. PMID:20643745

  12. CCSSM Challenge: Graphing Ratio and Proportion

    ERIC Educational Resources Information Center

    Kastberg, Signe E.; D'Ambrosio, Beatriz S.; Lynch-Davis, Kathleen; Mintos, Alexia; Krawczyk, Kathryn

    2013-01-01

    A renewed emphasis was placed on ratio and proportional reasoning in the middle grades in the Common Core State Standards for Mathematics (CCSSM). The expectation for students includes the ability to not only compute and then compare and interpret the results of computations in context but also interpret ratios and proportions as they are…

  13. Administrator-Teacher Ratio Study: Executive Summary.

    ERIC Educational Resources Information Center

    School Services of California, Inc., Sacramento.

    Since the early 1970s, financial penalties have been levied in California school districts if their administrator-to-teacher ratio is in excess of a standard set by law. A study was conducted to determine whether the provisions of administrator-teacher maximum ratio are effective for calculating, monitoring, and reporting administrative costs.

  14. Financial Ratio Analysis Comes to Nonprofits.

    ERIC Educational Resources Information Center

    Chabotar, Kent John

    1989-01-01

    To evaluate their financial health, a growing number of colleges, universities, and other nonprofit organizations are using financial ratio analysis, a technique used in business. The strengths and weaknesses of ratio analysis are assessed and suggestions are made on how nonprofits can use it most effectively. (Author/MLW)

  15. Osmosis and Surface Area to Volume Ratio.

    ERIC Educational Resources Information Center

    Barrett, D. R. B.

    1984-01-01

    Describes an experiment designed to help students understand the concepts of osmosis and surface area to volume ratio (SA:VOL). The task for students is to compare water uptake in different sizes of potato cubes and relate differences to their SA:VOL ratios. (JN)

  16. How to use and interpret hormone ratios.

    PubMed

    Sollberger, Silja; Ehlert, Ulrike

    2016-01-01

    Hormone ratios have become increasingly popular throughout the neuroendocrine literature since they offer a straightforward way to simultaneously analyze the effects of two interdependent hormones. However, the analysis of ratios is associated with statistical and interpretational concerns which have not been sufficiently considered in the context of endocrine research. The aim of this article, therefore, is to demonstrate and discuss these issues, and to suggest suitable ways to address them. In a first step, we use exemplary testosterone and cortisol data to illustrate that one major concern of ratios lies in their distribution and inherent asymmetry. As a consequence, results of parametric statistical analyses are affected by the ultimately arbitrary decision of which way around the ratio is computed (i.e., A/B or B/A). We suggest the use of non-parametric methods as well as the log-transformation of hormone ratios as appropriate methods to deal with these statistical problems. However, in a second step, we also discuss the complicated interpretation of ratios, and propose moderation analysis as an alternative and oftentimes more insightful approach to ratio analysis. In conclusion, we suggest that researchers carefully consider which statistical approach is best suited to investigate reciprocal hormone effects. With regard to the hormone ratio method, further research is needed to specify what exactly this index reflects on the biological level and in which cases it is a meaningful variable to analyze. PMID:26521052

  17. The Divine Ratio and Golden Rectangles.

    ERIC Educational Resources Information Center

    Cooper, Martin

    1982-01-01

    The material examines aspects of Fibonacci and Lucas sequences, the generation of the Divine Ratio, and the nature of this ratio in golden rectangles, triangles, and figures made up of golden triangles. It is noted Lucas sequence is formed like Fibonacci but has one and three as the first elements. (Author/MP)

  18. Administrator-Teacher Ratio Study: Executive Summary.

    ERIC Educational Resources Information Center

    School Services of California, Inc., Sacramento.

    Since the early 1970s, financial penalties have been levied in California school districts if their administrator-to-teacher ratio is in excess of a standard set by law. A study was conducted to determine whether the provisions of administrator-teacher maximum ratio are effective for calculating, monitoring, and reporting administrative costs.…

  19. 34 CFR 668.172 - Financial ratios.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., the Secretary determines an institution's composite score by— (1) Calculating the result of its...) Calculating the strength factor score for each of those ratios by using the corresponding algorithm; (3) Calculating the weighted score for each ratio by multiplying the strength factor score by its...

  20. 34 CFR 668.172 - Financial ratios.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., the Secretary determines an institution's composite score by— (1) Calculating the result of its...) Calculating the strength factor score for each of those ratios by using the corresponding algorithm; (3) Calculating the weighted score for each ratio by multiplying the strength factor score by its...

  1. 34 CFR 668.172 - Financial ratios.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., the Secretary determines an institution's composite score by— (1) Calculating the result of its...) Calculating the strength factor score for each of those ratios by using the corresponding algorithm; (3) Calculating the weighted score for each ratio by multiplying the strength factor score by its...

  2. 34 CFR 668.172 - Financial ratios.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., the Secretary determines an institution's composite score by— (1) Calculating the result of its...) Calculating the strength factor score for each of those ratios by using the corresponding algorithm; (3) Calculating the weighted score for each ratio by multiplying the strength factor score by its...

  3. 34 CFR 668.172 - Financial ratios.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., the Secretary determines an institution's composite score by— (1) Calculating the result of its...) Calculating the strength factor score for each of those ratios by using the corresponding algorithm; (3) Calculating the weighted score for each ratio by multiplying the strength factor score by its...

  4. Manganese nodules: thorium-230: protactinium-231 ratios.

    PubMed

    Sackett, W M

    1966-11-01

    The Th(230): Pa(231) activity ratio in 7 of 11 manganese nodules is less than 10.8, the theoretical production ratio of activities in the ocean. This finding indicates difierential accumulation of these nuclides in authigenic deposits of manganese-iron oxide. PMID:17778807

  5. Elastic vibrations of rods and Poisson's ratio

    NASA Astrophysics Data System (ADS)

    Davis, Timothy J.; Opat, Geoffrey I.

    1983-02-01

    We describe a simple experiment using a stereo phonograph cartridge for observing the longitudinal and torsional vibrations of a cylindrical rod. The elastic properties of the rod may thus be determined from measurements of its natural frequencies. Poisson's ratio, in particular, is determined to high precision directly from a simple frequency ratio.

  6. Sustainable sex ratio in lattice populations

    NASA Astrophysics Data System (ADS)

    Tainaka, K.; Hayashi, T.; Yoshimura, J.

    2006-05-01

    We present a lattice model of mating populations. Simulation is performed by two different methods: local and global interactions. Simulation results account for the reason why the observed sex ratio is nearly one half in many animals. The male-biased sex ratio, such as in human populations, is also explained.

  7. The Golden Ratio--A Contrary Viewpoint

    ERIC Educational Resources Information Center

    Falbo, Clement

    2005-01-01

    Many assertions about the occurrence of the golden ratio phi in art, architecture, and nature have been shown to be false, unsupported, or misleading. For instance, we show that the spirals found in sea shells, in particular the "Nautilus pompilius," are not in the shape of the golden ratio, as is often claimed. Some of the most interesting

  8. CCSSM Challenge: Graphing Ratio and Proportion

    ERIC Educational Resources Information Center

    Kastberg, Signe E.; D'Ambrosio, Beatriz S.; Lynch-Davis, Kathleen; Mintos, Alexia; Krawczyk, Kathryn

    2013-01-01

    A renewed emphasis was placed on ratio and proportional reasoning in the middle grades in the Common Core State Standards for Mathematics (CCSSM). The expectation for students includes the ability to not only compute and then compare and interpret the results of computations in context but also interpret ratios and proportions as they are

  9. Tower Water-Vapor Mixing Ratio

    SciTech Connect

    Guastad, Krista; Riihimaki, Laura; none,

    2013-04-01

    The purpose of the Tower Water-Vapor Mixing Ratio (TWRMR) value-added product (VAP) is to calculate water-vapor mixing ratio at the 25-meter and 60-meter levels of the meteorological tower at the Southern Great Plains (SGP) Central Facility.

  10. Sex ratios in pheasant research and management

    USGS Publications Warehouse

    Dale, F.H.

    1952-01-01

    Sex ratios are of primary importance in interpretation of extensive studies of pheasant populations. They are necessary for converting crowing-cock indices to population estimates even where annual trends are to be studied in the same area. Reliability of population estimates from hunting season kill of pheasants suffers primarily from inability to estimate sex ratios accurately. Fall sex ratio is an index to production and where adult sex ratios are divergent can serve as a good check on production per hen. Age ratios of cocks cannot be interpreted directly as an index of productivity, even within the boundaries of one state, unless adult sex ratios are known. The relationship between observed and actual sex ratio varies significantly from season to season and according to the method of observation. In view of their importance in population studies and the lack of reliability of present methods, it is believed that intensive studies on techniques for obtaining sex ratios are a major need in pheasant research.

  11. Scavenging ratios based on inflow air concentrations

    SciTech Connect

    Davis, W.E.; Dana, M.T.; Lee, R.N.; Slinn, W.G.N.; Thorp, J.M.

    1991-07-01

    Scavenging ratios were calculated from field measurements made during April 1985. Event precipitation samples were collected at the surface, but air chemistry measurements in the air mass feeding the precipitation were made from an aircraft. In contrast, ratios calculated in previous studies have used air concentration and precipitation chemistry data from only surface measurements. Average scavenging ratios were calculated for SO{sub 4}{sup 2{minus}}, NO{sub 3}{sup {minus}}, NH{sub 4}{sup +}, total sulfate, total nitrate, and total ammonium for 5 events; the geometric mean of these scavenging ratios were 8.5 {times} 10{sup 5}, 5.6 {times} 10{sup 6}, 4.3 {times} 10{sup 5}, 3.4 {times} 10{sup 5}, 2.4 {times} 10{sup 6}, and 9.7 {times} 10{sup 4}, respectively. These means are similar to but less variable than previous ratios formed using only surface data.

  12. 48 CFR 1602.170-14 - FEHB-specific medical loss ratio threshold calculation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 6 2011-10-01 2011-10-01 false FEHB-specific medical loss... DEFINITIONS OF WORDS AND TERMS Definitions of FEHBP Terms 1602.170-14 FEHB-specific medical loss ratio threshold calculation. (a) Medical loss ratio (MLR) means the ratio of plan incurred claims, including...

  13. Atmospheric helium isotope ratio: Possible temporal and spatial variations

    NASA Astrophysics Data System (ADS)

    Sano, Yuji; Furukawa, Yukiko; Takahata, Naoto

    2010-09-01

    The atmospheric 3He/ 4He ratio has been considered to be constant on a global scale, because the residence time of helium is significantly longer than the mixing time in the atmosphere. However, this ratio may be decreasing with time owing to the anthropogenic release of crustal helium from oil and natural gas wells, although this observation has been disputed. Here, we present the 3He/ 4He ratios of old air trapped in historical slags in Japan and of modern surface air samples collected at various sites around the world, measured with a newly developed analytical system. In air helium extracted from metallurgical slag found at refineries in operation between AD 1603 and 1907 in Japan, we determined a mean 3He/ 4He ratio of (5106 ± 108) × 10 -5 R HESJ (where R HESJ is the 3He/ 4He ratio of the Helium Standard of Japan), which is consistent with the previously reported value of (5077 ± 59) × 10 -5 R HESJ for historical slags in France and United Arab Emirates and about 4% higher than that of average modern air, (4901 ± 4) × 10 -5 R HESJ. This result implies that the air 3He/ 4He ratio has decreased with time as expected by anthropogenic causes. Our modern surface air samples revealed that the 3He/ 4He ratio increases from north to south at a rate of (0.16 ± 0.08) × 10 -5 R HESJ/degree of latitude, suggesting that the low 3He/ 4He ratio originates in high-latitude regions of the northern hemisphere, which is consistent with the fact that most fossil fuel is extracted and consumed in the northern hemisphere.

  14. CALIPSO Lidar Ratio Retrieval Over the Ocean

    NASA Technical Reports Server (NTRS)

    Josset, Damien B.; Rogers, Raymond R.; Pelon, Jacques; Hu, Yongxiang; Liu, Zhaoyan; Omar, Ali H.; Zhai, Peng-Wang

    2011-01-01

    We are demonstrating on a few cases the capability of CALIPSO to retrieve the 532 nm lidar ratio over the ocean when CloudSat surface scattering cross section is used as a constraint. We are presenting the algorithm used and comparisons with the column lidar ratio retrieved by the NASA airborne high spectral resolution lidar. For the three cases presented here, the agreement is fairly good. The average CALIPSO 532 nm column lidar ratio bias is 13.7% relative to HSRL, and the relative standard deviation is 13.6%. Considering the natural variability of aerosol microphysical properties, this level of accuracy is significant since the lidar ratio is a good indicator of aerosol types. We are discussing dependencies of the accuracy of retrieved aerosol lidar ratio on atmospheric aerosol homogeneity, lidar signal to noise ratio, and errors in the optical depth retrievals. We are obtaining the best result (bias 7% and standard deviation around 6%) for a nighttime case with a relatively constant lidar ratio (in the vertical) indicative of homogeneous aerosol type

  15. Sex ratio in relation to fathers' occupations.

    PubMed Central

    Dickinson, H O; Parker, L

    1997-01-01

    OBJECTIVE: To investigate whether the sex ratio of children varies between fathers of different occupations. METHODS: The sex ratio (the ratio of the number of boys to the number of girls at birth) was calculated in relation to paternal occupation in the cohort of all 253,433 live births in Cumbria, north west England, from 1950-89. Exact binomial confidence intervals were used to estimate whether the sex ratio in each occupational category was significantly different from that for the rest of the cohort. RESULTS: There were fewer occupational categories with significantly different sex ratios at the 5% level than expected by chance alone, assuming the same binomial distribution of sexes at birth within each paternal occupation. CONCLUSIONS: Significant variation of the sex ratio with fathers' occupations was not found. There is some evidence that the sex ratio shows less variance than expected under a binomial model which assumes independence of the sex of each child; a possible explanation of this may be parental preference for limiting family size after children of both sexes have been born or some other factor which results in children within a family being more likely to be of both sexes rather than the same sex. PMID:9470894

  16. Sex ratio at birth in Korea.

    PubMed

    Bae, W O

    1991-12-01

    Koreans exhibit a strong son preference, and there has been a rapid decline in fertility rates in Korea since 1960. Vital statistics data from 1979-88, population and housing census data from 1970-90, and national fertility surveys of 1985 and 1988 form the basis for this study of sex ratios at birth in Korea. The sex ratio is examined in light of sociodemographic effects, and the effect on population structure. Problems were encountered because of incomplete registration of births, imprecise determination of a normal range for the sex ratio at birth, and difficulty in identifying socioeconomic impact. The sex ratio at birth in favor of the male has increased since 1981 to 113.6 in 1988. Birth order is related to the sex ratio; i.e., there is an increasing excess of male births with higher parity. In 1988, the sex ratio was 170.5 at the third birth and 199.1 at the fourth birth. Since more than 50% of births are first parity births, the impact on the total sex ratio is minimal. The large imbalance in 1988 is in contrast to the reverse trend in 1972-80. The sex ratio at birth and the age of the mother are positively related. There are inconsistencies in the age group 15-19 and 40 years. Where there are more traditional areas which show son preference, such as in Daegu City and Gyongbuk, there were very high sex ratios in 1985 and 1988. Total fertility has declined from 4.7 in 1971 to 2.7 in 1982 and 1.63 in 1990, due primarily to socioeconomic development. 50.1% of women reported that a son was either essential or better. Son preference is high in all age and educational groups. 67.4% desired a son if it was an only child, 28.3% preferred a son, and 66.5% had no preference. Childbearing would cease if the first child was a son, but parents would have one more child in an attempt to have a son, if a daughter was first born. Ultrasound testing involved 3.9% of a sample population, and 1.2% of latest pregnancies, of which 31% were aborted females. Abortion of female pregnancy occurs because of son preference. The sex ratio is expected to remain uniform until 2020 when population is projected at age 0 assuming a sex ratio of 107. The school age and marriageable population would reflect this imbalance. The sex ratio of the marriageable would increase to 113.7 between 2010 and 2019. PMID:12179748

  17. The golden ratio in facial symmetry.

    PubMed

    Prokopakis, E P; Vlastos, I M; Picavet, V A; Nolst Trenite, G; Thomas, R; Cingi, C; Hellings, P W

    2013-03-01

    Symmetry is believed to be a hallmark of appealing faces. However, this does not imply that the most aesthetically pleasing proportions are necessary those that arise from the simple division of the face into thirds or fifths. Based on the etymology of the word symmetry, as well as on specific examples and theories of beauty, we conclude that ?-value, a ratio also known as the golden ratio or the divine proportion, can also characterize symmetrical forms. Therefore, we propose the utilization of this ratio in facial aesthetics. PMID:23441307

  18. S V line ratios in the sun

    SciTech Connect

    Dufton, P.L.; Hibbert, A.; Keenan, F.P.; Kingston, A.E.; Doschek, G.A.

    1986-01-01

    In the present prediction of level populations and emission line intensity ratios for electron densities and temperatures appropriate to the sun, on the basis of new atomic data for S V, the electron impact collision rates for spin-forbidden transitions and the intercombination transition spontaneous radiative rate are noted to be substantially larger than previously ascertained. The S V intensity ratio is shown to be a useful electron density diagnostic for log N(e) greater than 11.5 ratios deduced from observations obtained with a slit spectrograph aboard Skylab generally agree with the theoretical values presented. 29 references.

  19. Optimal sampling ratios in comparative diagnostic trials

    PubMed Central

    Dong, Ting; Tang, Liansheng Larry; Rosenberger, William F.

    2014-01-01

    Summary A subjective sampling ratio between the case and the control groups is not always an efficient choice to maximize the power or to minimize the total required sample size in comparative diagnostic trials.We derive explicit expressions for an optimal sampling ratio based on a common variance structure shared by several existing summary statistics of the receiver operating characteristic curve. We propose a two-stage procedure to estimate adaptively the optimal ratio without pilot data. We investigate the properties of the proposed method through theoretical proofs, extensive simulation studies and a real example in cancer diagnostic studies. PMID:24948841

  20. Hybrid LTA vehicle controllability as affected by buoyancy ratio

    NASA Technical Reports Server (NTRS)

    Meyers, D. N.; Kubicki, P.; Tarczynski, T.; Fairbanks, A.; Piasecki, F. N.

    1979-01-01

    The zero and low speed controllability of heavy lift airships under various wind conditions as affected by the buoyancy ratio are investigated. A series of three hybrid LTA vehicls were examined, each having a dynamic thrust system comprised of four H-34 helicopters, but with buoyant envelopes of different volumes (and hence buoyancies), and with varying percentage of helium inflation and varying useful loads (hence gross weights). Buoyancy ratio, B, was thus examined varying from approximately 0.44 to 1.39. For values of B greater than 1.0, the dynamic thrusters must supply negative thrust (i.e. downward).

  1. Experimental evaluation of blockage ratio and plenum evacuation system flow effects on pressure distribution for bodies of revolution in 0.1 scale model test section of NASA Lewis Research Center's proposed altitude wind tunnel

    NASA Technical Reports Server (NTRS)

    Burley, Richard R.; Harrington, Douglas E.

    1987-01-01

    An experimental investigation was conducted in the slotted test section of the 0.1-scale model of the proposed Altitude Wind Tunnel to evaluate wall interference effects at tunnel Mach numbers from 0.70 to 0.95 on bodies of revolution with blockage rates of 0.43, 3, 6, and 12 percent. The amount of flow that had to be removed from the plenum chamber (which surrounded the slotted test section) by the plenum evacuation system (PES) to eliminate wall interference effects was determined. The effectiveness of tunnel reentry flaps in removing flow from the plenum chamber was examined. The 0.43-percent blockage model was the only one free of wall interference effects with no PES flow. Surface pressures on the forward part of the other models were greater than interference-free results and were not influenced by PES flow. Interference-free results were achieved on the aft part of the 3- and 6-percent blockage models with the proper amount of PES flow. The required PES flow was substantially reduced by opening the reentry flaps.

  2. Doing Mathematics with Bicycle Gear Ratios.

    ERIC Educational Resources Information Center

    Stump, Sheryl L.

    2000-01-01

    Describes an activity in which students examine bicycle chain-rings, cogs, and gear ratios as a means of exploring algebraic relationships, data collection, scatter plots, and lines of best fit. (KHR)

  3. Science Application of Area and Ratio Concepts

    ERIC Educational Resources Information Center

    Horak, Virginia M.

    2006-01-01

    This article describes using area and ratio concepts to examine why some animals, or people wearing different types of shoes, sink into the surface on which they are standing. Students compute "sinking values" to explain these differences. (Contains 2 figures.)

  4. Carbon and Oxygen Isotopic Ratios for Miras

    NASA Astrophysics Data System (ADS)

    Hinkle, Kenneth H.; Lebzelter, Thomas; Straniero, Oscar

    2016-01-01

    We have measured vibration-rotation first and second overtone 12C16O, 13C16O, 12C17O, 12C18O lines in 1.5 to 2.5 micron spectra of 41 Mira and SRa stars. These measurements have been used to derive 12C/13C, 16O/17O, and 16O/18O isotopic ratios. The ratios are compared to available literature values for the individual stars and the ratios are compared to isotopic ratios for various samples of evolved stars. Models for solar composition AGB stars of different initial masses are compared to the results. We find that the majority of the M stars had main sequence masses <1.5 solar mass and have not experienced the third dredge up. The progenitors of the S and C Miras in the sample were more massive but no stars in the sample show evidence of hot bottom burning.

  5. Fe XIV line ratios in the sun

    SciTech Connect

    Keenan, F.P.; Dufton, P.L.; Boylan, M.B.; Kingston, A.E.; Widing, K.G. U.S. Navy, E.O. Hulburt Center for Space Research, Washington, DC )

    1991-06-01

    Recent R-matrix calculations of electron-impact excitation rates for Fe XIV are used to derive theoretical electron density-sensitive emission-line ratios involving transitions in the wavelength range 211-274 A. Electron densities deduced from the observed line ratios for solar flares and active regions, obtained with the Naval Research Laboratory's SO82A slitless spectrograph on board Skylab, are in excellent internal agreement and, furthermore, compare favorably with densities determined independently from line ratios in Fe XII and Fe XIII. These results provide experimental support for the accuracy of the atomic data adopted in the analysis, as well as for the techniques used to calculate the line ratios. 36 refs.

  6. Numerical Estimation of the Spent Fuel Ratio

    SciTech Connect

    Lindgren, Eric R.; Durbin, Samuel; Wilke, Jason; Margraf, J.; Dunn, T. A.

    2016-01-01

    Sabotage of spent nuclear fuel casks remains a concern nearly forty years after attacks against shipment casks were first analyzed and has a renewed relevance in the post-9/11 environment. A limited number of full-scale tests and supporting efforts using surrogate materials, typically depleted uranium dioxide (DUO 2 ), have been conducted in the interim to more definitively determine the source term from these postulated events. However, the validity of these large- scale results remain in question due to the lack of a defensible spent fuel ratio (SFR), defined as the amount of respirable aerosol generated by an attack on a mass of spent fuel compared to that of an otherwise identical surrogate. Previous attempts to define the SFR in the 1980's have resulted in estimates ranging from 0.42 to 12 and include suboptimal experimental techniques and data comparisons. Because of the large uncertainty surrounding the SFR, estimates of releases from security-related events may be unnecessarily conservative. Credible arguments exist that the SFR does not exceed a value of unity. A defensible determination of the SFR in this lower range would greatly reduce the calculated risk associated with the transport and storage of spent nuclear fuel in dry cask systems. In the present work, the shock physics codes CTH and ALE3D were used to simulate spent nuclear fuel (SNF) and DUO 2 targets impacted by a high-velocity jet at an ambient temperature condition. These preliminary results are used to illustrate an approach to estimate the respirable release fraction for each type of material and ultimately, an estimate of the SFR. This page intentionally blank

  7. Approaches to high aspect ratio triangulations

    NASA Technical Reports Server (NTRS)

    Posenau, M.-A.

    1993-01-01

    In aerospace computational fluid dynamics calculations, high aspect ratio, or stretched, triangulations are necessary to adequately resolve the features of a viscous flow around bodies. In this paper, we explore alternatives to the Delaunay triangulation which can be used to generate high aspect ratio triangulations of point sets. The method is based on a variation of the lifting map concept which derives Delaunay triangulations from convex hull calculations.

  8. Element abundance ratios in stellar population modelling

    NASA Astrophysics Data System (ADS)

    Thomas, Daniel

    2015-08-01

    The chemical element abundance ratios in the stellar populations of galaxies can be used not only to constrain the chemical enrichment histories of galaxies, but also provide a powerful tool for the derivation of the timescales over which their stars were formed. I will review methods to derive element ratios for unresolved stellar populations from stellar population modelling, and discuss implications from the measured chemistry of galaxies for galaxy formation theory.

  9. The Charon-Pluto mass ratio from MKO astrometry

    NASA Technical Reports Server (NTRS)

    Young, L. A.; Olkin, C. B.; Elliot, J. L.; Tholen, D. J.; Buie, M. W.

    1994-01-01

    Using the University of Hawaii (UH) 2.2-m telescope, we obtained charge coupled device (CCD) images of Pluto as it passed through a single field of 10 stars during 6 nights of Charon's 6.4-day orbital period. From these data, Charon's orbital semimajor axis is found to be 19,460 +/- 58 km, which is consistent with the recent measurement by Null et al. (1993), of 19,405 +/- 86 km. Our semimajor axis implies a system mass of (14.32 +/- 0.13) x 10(exp 24) g. From the motions of Pluto and Charon around their barycenter, we find that the ratio of Charon's mass to Pluto's is 0.1566 +/- 0.0035, indicating that the bodies both have densities near 2 g/cc. Our ratio is nearly twice that of Null et al., who find a ratio of 0.0837 +/- 0.0147. Possible reasons for the large discrepancy are discussed.

  10. The Charon-Pluto mass ratio from MKO astrometry

    NASA Astrophysics Data System (ADS)

    Young, L. A.; Olkin, C. B.; Elliot, J. L.; Tholen, D. J.; Buie, M. W.

    1994-04-01

    Using the University of Hawaii (UH) 2.2-m telescope, we obtained charge coupled device (CCD) images of Pluto as it passed through a single field of 10 stars during 6 nights of Charon's 6.4-day orbital period. From these data, Charon's orbital semimajor axis is found to be 19,460 +/- 58 km, which is consistent with the recent measurement by Null et al. (1993), of 19,405 +/- 86 km. Our semimajor axis implies a system mass of (14.32 +/- 0.13) x 1024 g. From the motions of Pluto and Charon around their barycenter, we find that the ratio of Charon's mass to Pluto's is 0.1566 +/- 0.0035, indicating that the bodies both have densities near 2 g/cc. Our ratio is nearly twice that of Null et al., who find a ratio of 0.0837 +/- 0.0147. Possible reasons for the large discrepancy are discussed.

  11. Tone prominence ratio, error sources, and proposed solutions

    NASA Astrophysics Data System (ADS)

    Stanley, G. (Randy); Demoss, Jeffrey; Damani, Anil

    2005-09-01

    Tone prominence ratio is finding increasing use as a tool for product sound design. ECMA-74 Annex D offers a procedure for calculating tone prominence ratio and qualifying tone audibility. However, there are significant potential sources of error when utilizing the ECMA-74 procedure. These include possible misidentification of tone frequency, and ambiguities about what constitutes tone audibility. Misidentification of tone frequency can occur when closely spaced tones exist in the spectrum; whereas, other errors may result from individual subjective assessment of tone audibility. The existing ECMA method does not specify how to identify the primary tone frequency when such ambiguities exist. Real-world examples of potential error sources are presented along with proposed solutions. An unambiguous peak prominence ratio value reporting system is presented along with data to support its improved relevance in terms of hearing perception and subjective annoyance.

  12. Sex ratio evolution under probabilistic sex determination.

    PubMed

    Paixo, Tiago; Phadke, Sujal S; Azevedo, Ricardo B R; Zufall, Rebecca A

    2011-07-01

    Sex allocation theory has been remarkably successful at explaining the prevalence of even sex ratios in natural populations and at identifying specific conditions that can result in biased sex ratios. Much of this theory focuses on parental sex determination (SD) strategies. Here, we consider instead the evolutionary causes and consequences of mixed offspring SD strategies, in which the genotype of an individual determines not its sex, but the probability of developing one of multiple sexes. We find that alleles specifying mixed offspring SD strategies can generally outcompete alleles that specify pure strategies, but generate constraints that may prevent a population from reaching an even sex ratio. We use our model to analyze sex ratios in natural populations of Tetrahymena thermophila, a ciliate with seven sexes determined by mixed SD alleles. We show that probabilistic SD is sufficient to account for the occurrence of skewed sex ratios in natural populations of T. thermophila, provided that their effective population sizes are small. Our results highlight the importance of genetic drift in sex ratio evolution and suggest that mixed offspring SD strategies should be more common than currently thought. PMID:21729059

  13. A note on trader Sharpe Ratios.

    PubMed

    Coates, John M; Page, Lionel

    2009-01-01

    Traders in the financial world are assessed by the amount of money they make and, increasingly, by the amount of money they make per unit of risk taken, a measure known as the Sharpe Ratio. Little is known about the average Sharpe Ratio among traders, but the Efficient Market Hypothesis suggests that traders, like asset managers, should not outperform the broad market. Here we report the findings of a study conducted in the City of London which shows that a population of experienced traders attain Sharpe Ratios significantly higher than the broad market. To explain this anomaly we examine a surrogate marker of prenatal androgen exposure, the second-to-fourth finger length ratio (2D:4D), which has previously been identified as predicting a trader's long term profitability. We find that it predicts the amount of risk taken by traders but not their Sharpe Ratios. We do, however, find that the traders' Sharpe Ratios increase markedly with the number of years they have traded, a result suggesting that learning plays a role in increasing the returns of traders. Our findings present anomalous data for the Efficient Markets Hypothesis. PMID:19946367

  14. A Note on Trader Sharpe Ratios

    PubMed Central

    Coates, John M.; Page, Lionel

    2009-01-01

    Traders in the financial world are assessed by the amount of money they make and, increasingly, by the amount of money they make per unit of risk taken, a measure known as the Sharpe Ratio. Little is known about the average Sharpe Ratio among traders, but the Efficient Market Hypothesis suggests that traders, like asset managers, should not outperform the broad market. Here we report the findings of a study conducted in the City of London which shows that a population of experienced traders attain Sharpe Ratios significantly higher than the broad market. To explain this anomaly we examine a surrogate marker of prenatal androgen exposure, the second-to-fourth finger length ratio (2D?4D), which has previously been identified as predicting a trader's long term profitability. We find that it predicts the amount of risk taken by traders but not their Sharpe Ratios. We do, however, find that the traders' Sharpe Ratios increase markedly with the number of years they have traded, a result suggesting that learning plays a role in increasing the returns of traders. Our findings present anomalous data for the Efficient Markets Hypothesis. PMID:19946367

  15. Plutonium isotope ratio variations in North America

    SciTech Connect

    Steiner, Robert E; La Mont, Stephen P; Eisele, William F; Fresquez, Philip R; Mc Naughton, Michael; Whicker, Jeffrey J

    2010-12-14

    Historically, approximately 12,000 TBq of plutonium was distributed throughout the global biosphere by thermo nuclear weapons testing. The resultant global plutonium fallout is a complex mixture whose {sup 240}Pu/{sup 239}Pu atom ratio is a function of the design and yield of the devices tested. The average {sup 240}Pu/{sup 239}Pu atom ratio in global fallout is 0.176 + 014. However, the {sup 240}Pu/{sup 239}Pu atom ratio at any location may differ significantly from 0.176. Plutonium has also been released by discharges and accidents associated with the commercial and weapons related nuclear industries. At many locations contributions from this plutonium significantly alters the {sup 240}Pu/{sup 239}Pu atom ratios from those observed in global fallout. We have measured the {sup 240}Pu/{sup 239}Pu atom ratios in environmental samples collected from many locations in North America. This presentation will summarize the analytical results from these measurements. Special emphasis will be placed on interpretation of the significance of the {sup 240}Pu/{sup 239}Pu atom ratios measured in environmental samples collected in the Arctic and in the western portions of the United States.

  16. On ratio-based color indexing.

    PubMed

    Adjeroh, D A; Lee, M C

    2001-01-01

    The color ratio approach to indexing has been found to be robust and effective in indexing image and video databases, in different color spaces, and when using transformed color features, such as those from the Karhunen-Loeve transform (KLT) or the discrete cosine transform (DCT). However, the reason for the superior performance of the color ratio model, especially on different color spaces or with transformed color features has, at best, been speculative. This paper develops a generalized form for the color ratio model, based on which we characterize the general distribution of the color ratios. From the distribution, we present a theory that explains and supports the performance of the color ratio approach in image and video indexing. It is shown that the same theory accounts for its effectiveness in different color spaces and in the transform domain. Some general problems encountered in using the original retinex lightness algorithm, and some other issues specific to ratio-based color indexing are discussed in the light of the theory. Results are presented which show that the proposed theory is supported by empirical evidence. PMID:18249595

  17. The HNC/HCN ratio in star-forming regions

    SciTech Connect

    Graninger, Dawn M.; Öberg, Karin I.; Herbst, Eric; Vasyunin, Anton I.

    2014-05-20

    HNC and HCN, typically used as dense gas tracers in molecular clouds, are a pair of isomers that have great potential as a temperature probe because of temperature dependent, isomer-specific formation and destruction pathways. Previous observations of the HNC/HCN abundance ratio show that the ratio decreases with increasing temperature, something that standard astrochemical models cannot reproduce. We have undertaken a detailed parameter study on which environmental characteristics and chemical reactions affect the HNC/HCN ratio and can thus contribute to the observed dependence. Using existing gas and gas-grain models updated with new reactions and reaction barriers, we find that in static models the H + HNC gas-phase reaction regulates the HNC/HCN ratio under all conditions, except for very early times. We quantitatively constrain the combinations of H abundance and H + HNC reaction barrier that can explain the observed HNC/HCN temperature dependence and discuss the implications in light of new quantum chemical calculations. In warm-up models, gas-grain chemistry contributes significantly to the predicted HNC/HCN ratio and understanding the dynamics of star formation is therefore key to model the HNC/HCN system.

  18. Higher surface Bowen ratios ineffective at increasing updraft intensity

    NASA Astrophysics Data System (ADS)

    Hansen, Zachary R.; Back, Larissa E.

    2015-12-01

    The sensitivity of various metrics of convective intensity to changes in boundary layer depth via changes in the surface Bowen ratio is explored with radiative-convective equilibrium (RCE) and initial condition simulations in the System for Atmospheric Modeling, a cloud-resolving model. In the RCE simulations, high-percentile updrafts showed little change in response to changes in the surface Bowen ratio. Initial condition simulations showed low surface Bowen ratios having stronger updrafts than high surface Bowen ratios. A parcel model was used to explore whether RCE results could be explained with an entrainment parameter independent of boundary layer depth. It was found that for every set of simulations in RCE, entrainment rates independent of boundary layer depth could explain the lack of change in updraft velocities with boundary layer depth. Given the indifference of high-percentile updraft velocities in our simulations to changes in the surface Bowen ratio, we conclude that convective intensity as measured by this quantity in the cloud-resolving model is not sensitive to this forcing.

  19. Directional spectral emissivity measurement system

    NASA Technical Reports Server (NTRS)

    Halyo, Nesim (Inventor); Pandey, Dhirendra K. (Inventor)

    1992-01-01

    Apparatus and process for determining the emissivity of a test specimen including an integrated sphere having two concentric walls with a coolant circulating therebetween, and disposed within a chamber which may be under ambient, vacuum or inert gas conditions. A reference sample is disposed within the sphere with a monochromatic light source in optical alignment therewith. A pyrometer is in optical alignment with the test sample for obtaining continuous test sample temperature measurements during a test. An arcuate slit port is provided through the spaced concentric walls of the integrating sphere with a movable monochromatic light source extending through and movable along the arcuate slit port. A detector system extends through the integrating sphere for continuously detecting an integrated signal indicative of all radiation within its field of view, as a function of the emissivity of the test specimen at various temperatures and various angle position of the monochromatic light source. A furnace for heating the test sample to approximately 3000 K. and control mechanism for transferring the heated sample from the furnace to the test sample port in the integrating sphere is also contained within the chamber.

  20. Temperature-controlled electrothermal atomization-atomic absorption spectrometry using a pyrometric feedback system in conjunction with a background monitoring device

    NASA Astrophysics Data System (ADS)

    Van Deijck, W.; Roelofsen, A. M.; Pieters, H. J.; Herber, R. F. M.

    The construction of a temperature-controlled feedback system for electrothermal atomization-atomic absorption spectrometry (ETA-AAS) using an optical pyrometer applied to the atomization stage is described. The system was used in conjunction with a fast-response background monitoring device. The heating rate of the furnace amounted to 1400° s -1 with a reproducibility better than 1%. The precision of the temperature control at a steady state temperature of 2000°C was 0.1%. The analytical improvements offered by the present system have been demonstrated by the determination of cadmium and lead in blood and finally by the determination of lead in serum. Both the sensitivity and the precision of the method have been improved. The accuracy of the method was checked by determining the lead content for a number of scrum samples both by ETA-AAS and differential pulse anodic stripping voltametry (DPASV) and proved to be satisfactory.