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Sample records for operating characteristics sroc

  1. CASSINI RSS RAW DATA SET - SROC20 V1.0

    National Aeronautics and Space Administration — The Cassini Radio Science Saturn Ring and Atmospheric Occultation experiments (SROC20) Raw Data Archive is a time-ordered collection of radio science raw data...

  2. Characteristics of operating pipelines

    Gallyamov, A K; Armenskii, E A; Gimaev, R G; Mastobaev, B N; Shammazov, A M

    1977-04-01

    The interval in pressure changes according to operational data for the Kamennyi Log--Perm oil pipeline was determined with the aid of the pattern identification method. This has made it possible to determine pressure changes in the operational process. 2 references, 1 table.

  3. Characteristics of public roads operation

    Pryimak, V.; Kyiashko, I.

    2009-01-01

    Characteristics of public roads operation have been considered and factors influencing TEC of public roads that go via urban areas have been determined. There have been revealed contradictions in the normative-legal base concerning maintenance of public roads and municipal roads that merge into them.

  4. Some characteristics of offshore operations

    Popov Đorđe

    2011-01-01

    Full Text Available Offshore operations are not on the margins of the world economy. They are an integral part of modern business practice. They have become one of the most important instruments in the contemporary globalized financial system. Offshore operations and tax havens are not only conduits for tax avoidance and evasion but belong more broadly to the world of finance, for the business of managing the monetary resources of an organization, country or individuals. Offshore business operating in tax havens is at the heart of a particular type of globalization that is characterized by a growing gap between the very rich and everyone else. Tax havens are financial conduits that, in exchange for a fee, use their one principal asset- their sovereignty to serve a nonresident constituency of accountants and lawyers, bankers and financiers, who bring a demand for offshore operations.

  5. 49 CFR 236.717 - Characteristics, operating.

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Characteristics, operating. 236.717 Section 236.717 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... § 236.717 Characteristics, operating. The measure of electrical values at which electrical or electronic...

  6. Surgical Site Infections and Associated Operative Characteristics.

    Waltz, Paul K; Zuckerbraun, Brian S

    Surgical site infection (SSI) contributes significantly to surgical morbidity. Patient factors and operative factors contribute to the risk of development of SSI. This review focuses on understanding operative characteristics that are associated with an increased risk of SSI. Much attention has been given to protocol care to reduce SSI, such as hair removal, skin preparation, and pre-operative antibiotic agents. Even with this, the appropriate antibiotic and re-dosing regimens often remain a challenge. Other operative factors such as blood loss/transfusion, emergency/urgent cases, duration of the operation, type of anesthesia, and resident involvement are also potentially modifiable to reduce the risk of SSI. Data are reviewed to highlight the increased risk associated with such factors. Strategies to reduce risk, such as operative care bundles, have significant promise to reduce the incidence of SSI for any given procedure.

  7. 14 CFR 29.939 - Turbine engine operating characteristics.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Turbine engine operating characteristics....939 Turbine engine operating characteristics. (a) Turbine engine operating characteristics must be investigated in flight to determine that no adverse characteristics (such as stall, surge, of flameout) are...

  8. 14 CFR 23.939 - Powerplant operating characteristics.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Powerplant operating characteristics. 23... General § 23.939 Powerplant operating characteristics. (a) Turbine engine powerplant operating characteristics must be investigated in flight to determine that no adverse characteristics (such as stall, surge...

  9. 14 CFR 25.939 - Turbine engine operating characteristics.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Turbine engine operating characteristics... engine operating characteristics. (a) Turbine engine operating characteristics must be investigated in flight to determine that no adverse characteristics (such as stall, surge, or flameout) are present, to a...

  10. 14 CFR 27.939 - Turbine engine operating characteristics.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Turbine engine operating characteristics....939 Turbine engine operating characteristics. (a) Turbine engine operating characteristics must be investigated in flight to determine that no adverse characteristics (such as stall, surge, or flameout) are...

  11. Operation characteristics of a multiple type MCFC

    Kuroe, S.; Kamo, T. [Hitachi Research Lab., Hitachi, Ltd., Ibaraki-ken (Japan); Fujimura, H.; Kahara, T. [Hitachi, Ltd., Ibaraki-ken (Japan)

    1996-12-31

    Multiple type structure of MCFC of which the separator of the cell is divided by four element cells has been studied. For the stable operation of this type cell, the effect of gas flow rate and temperature distribution on the cell voltage should be clear. In order to clarify these characteristics, a small sized mimic model has been made and tested. The flow rate distribution for the four element cells were varied and cell voltage and temperature distribution were measured for each cell. The decrease in cell voltage and the increase in maximum temperature became remarkable when the apparent utilization factor for one element cell became over 100%. The calculated results agreed fairly good with test results.

  12. Operational characteristics of VEC vacuum system

    Viswanadham, C.; Bhavsar, S.T.; Bose, D.K.; Chintalapudi, S.N.; Das, S.K.; Tiwary, S.D.

    1979-01-01

    The main vacuum system of the Variable Energy Cyclotron which has been built indigenously has fulfilled the requirements for the smooth operation of the machine. By running two 88.9 cm diffusion pumps with freon cooled baffles and backed by 600 l/m rotary pumps, a pressure of 5 x 10 -6 torr in absence of the beam and 1 x 10 -5 torr in presence of the beam is readily achieved in the 23 m 3 volume. Various means have been adopted to maintain the system in order and contamination-free, by maintaining a pressure level of 1 x 10 -4 torr throughout the working week by a 30 cm diffusion pump, which can run even on emergency power. Cryopanels have also been installed and tried out. Details of pump-down characteristics and system performance are discussed. (auth.)

  13. Receiver operator characteristic (ROC) analysis without truth

    Henkelman, R.M.; Kay, I.; Bronskill, M.J.

    1990-01-01

    Receiver operator characteristic (ROC) analysis, the preferred method of evaluating diagnostic imaging tests, requires an independent assessment of the true state of disease, which can be difficult to obtain and is often of questionable accuracy. A new method of analysis is described which does not require independent truth data and which can be used when several accurate tests are being compared. This method uses correlative information to estimate the underlying model of multivariate normal distributions of disease-positive and disease-negative patients. The method is shown to give results equivalent to conventional ROC analysis in a comparison of computed tomography, radionuclide scintigraphy, and magnetic resonance imaging for liver metastasis. When independent truth is available, the method can be extended to incorporate truth data or to evaluate the consistency of the truth data with the imaging data

  14. 33 CFR 157.158 - COW operations: Changed characteristics.

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false COW operations: Changed... CARRYING OIL IN BULK Crude Oil Washing (COW) System on Tank Vessels Cow Operations § 157.158 COW operations: Changed characteristics. The COW system may be operated with characteristics that do not meet those...

  15. Research about reactor operator's personality characteristics and performance

    Wei Li; He Xuhong; Zhao Bingquan

    2003-01-01

    To predict and evaluate the reactor operator's performance by personality characteristics is an important part of reactor operator safety assessment. Using related psychological theory combined with the Chinese operator's fact and considering the effect of environmental factors to personality analysis, paper does the research about the about the relationships between reactor operator's performance and personality characteristics, and offers the reference for operator's selection, using and performance in the future. (author)

  16. Steady-state Operational Characteristics of Ghana Research ...

    Steady state operational characteristics of the 30 kW tank-in-pool type reactor named Ghana Research Reactor-1 were investigated after a successful on-site zero power critical experiments. The steadystate operational character-istics determined were the thermal neutron fluxes, maximum period of operation at nominal ...

  17. Operational characteristics of nuclear power plants - modelling of operational safety

    Studovic, M.

    1984-01-01

    By operational experience of nuclear power plants and realize dlevel of availability of plant, systems and componenst reliabiliuty, operational safety and public protection, as a source on nature of distrurbances in power plant systems and lessons drawn by the TMI-2, in th epaper are discussed: examination of design safety for ultimate ensuring of safe operational conditions of the nuclear power plant; significance of the adequate action for keeping proess parameters in prescribed limits and reactor cooling rquirements; developed systems for measurements detection and monitoring all critical parameters in the nuclear steam supply system; contents of theoretical investigation and mathematical modeling of the physical phenomena and process in nuclear power plant system and components as software, supporting for ensuring of operational safety and new access in staff education process; program and progress of the investigation of some physical phenomena and mathematical modeling of nuclear plant transients, prepared at faculty of mechanical Engineering in Belgrade. (author)

  18. Important characteristics of operational force members

    Van Heerden, Adelai

    2017-10-01

    Full Text Available The operational forces military context is generally acknowledged as one of the most stressful contexts as it is demanding of members on a physical, psychological, social level with organisational, intra- and inter-personal demands of an extreme...

  19. Operational Characteristics of an Ultra Compact Combustor

    2014-03-27

    UCC operation caused by the UCC itself acting as a nozzle. This decrease in area was quantified by Radtke [22] at 47% for the AFRL UCC and causes...results in lower work potential for the engine as Mach numbers are already elevated. Radtke [22] quantified total Rayleigh losses with the AFRL...theory and experiment is by the constant area with heat addition assumption. Radtke [22] notes that his UCC configuration did not maintain a

  20. 7 CFR 43.105 - Operating characteristics (OC) curves.

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Operating characteristics (OC) curves. 43.105 Section 43.105 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE... CONTAINER REGULATIONS STANDARDS FOR SAMPLING PLANS Sampling Plans § 43.105 Operating characteristics (OC...

  1. Operating Characteristics of the low energy accelerator

    Abd El-Baki, M.M.; Abd El-Rahman, M.M.

    2000-01-01

    The main purpose of this work is to describe the construction and operation of low energy accelerator with energy in the range from (zero to 100 KeV.). This accelerator includes an ion source of the cold cathode penning type (with pierce geometry for ion beam extraction), an accelerating tube (with 8 electrodes) and faraday cup for measuring ion current. A vacuum system which gives vacuum of the order 3.0 x 10 8 torr is used. A palladium tube is used to supply the source with pure hydrogen atoms. It was possible to operate this accelerator with an energy 50 KeV. at minimum hydrogen pressure. 6.3 x 10 6 torr. The total resistance applied between the accelerating electrodes R T = 31.5 M OMEGA. These data includes the influence of the pressure in the accelerating tube, the magnetic field of the ion source, the extraction potential and the accelerating potential on the collector ion current. It was possible to accelerate protons with an energy 50 KeV with current about 100 MU A at pressure 6.3 x 10 6 Torr, the source magnetic field + 1100 gauss (I B = 2A), the current = 0.4 A and the extraction potential = 10 K. V

  2. Research of psychological characteristics and performance relativity of operators

    Fang Xiang; He Xuhong; Zhao Bingquan

    2008-01-01

    Based on the working tasks of an operator being taken into full consideration in this paper, on the one hand the table of measuring psychological characteristics is designed through the selection of special dimensions; on the other hand the table of performance appraisal is drafted through the choice of suitable standards of an operator. The paper analyzes the results of two aspects, sets relevant nuclear power plant operators as the research objective, and obtains the psychological characteristics and performance relativity of operators. The research can be as important and applied reference for the selection, evaluation and use of operators

  3. Operational Characteristics of an Accelerator Driven Fissile Solution System

    Kimpland, Robert Herbert

    2016-01-01

    Operational characteristics represent the set of responses that a nuclear system exhibits during normal operation. Operators rely on this behavior to assess the status of the system and to predict the consequences of off-normal events. These characteristics largely refer to the relationship between power and system operating conditions. The static and dynamic behavior of a chain-reacting system, operating at sufficient power, is primarily governed by reactivity effects. The science of reactor physics has identified and evaluated a number of such effects, including Doppler broadening and shifts in the thermal neutron spectrum. Often these reactivity effects are quantified in the form of feedback coefficients that serve as coupling coefficients relating the neutron population and the physical mechanisms that drive reactivity effects, such as fissile material temperature and density changes. The operational characteristics of such nuclear systems usually manifest themselves when perturbations between system power (neutron population) and system operating conditions arise. Successful operation of such systems requires the establishment of steady equilibrium conditions. However, prior to obtaining the desired equilibrium (steady-state) conditions, an approach from zero-power (startup) must occur. This operational regime may possess certain limiting system conditions that must be maintained to achieve effective startup. Once steady-state is achieved, a key characteristic of this operational regime is the level of stability that the system possesses. Finally, a third operational regime, shutdown, may also possess limiting conditions of operation that must be maintained. This report documents the operational characteristics of a ''generic'' Accelerator Driven Fissile Solution (ADFS) system during the various operational regimes of startup, steady-state operation, and shutdown. Typical time-dependent behavior for each operational regime will be illustrated, and key system

  4. Characteristic and Wigner function for number difference and operational phase

    Fan Hongyi; Hu Haipeng

    2004-01-01

    We introduce the characteristic function in the sense of number difference-operational phase, and we employ the correlated-amplitude-number-difference state representation to calculate it. It results in the form of the corresponding Wigner function and Wigner operator. The marginal distributions of the generalized Wigner function are briefly discussed

  5. Smooth time-dependent receiver operating characteristic curve estimators.

    Martínez-Camblor, Pablo; Pardo-Fernández, Juan Carlos

    2018-03-01

    The receiver operating characteristic curve is a popular graphical method often used to study the diagnostic capacity of continuous (bio)markers. When the considered outcome is a time-dependent variable, two main extensions have been proposed: the cumulative/dynamic receiver operating characteristic curve and the incident/dynamic receiver operating characteristic curve. In both cases, the main problem for developing appropriate estimators is the estimation of the joint distribution of the variables time-to-event and marker. As usual, different approximations lead to different estimators. In this article, the authors explore the use of a bivariate kernel density estimator which accounts for censored observations in the sample and produces smooth estimators of the time-dependent receiver operating characteristic curves. The performance of the resulting cumulative/dynamic and incident/dynamic receiver operating characteristic curves is studied by means of Monte Carlo simulations. Additionally, the influence of the choice of the required smoothing parameters is explored. Finally, two real-applications are considered. An R package is also provided as a complement to this article.

  6. Test results and operational characteristics of prototype SSCL half cell

    McInturff, A.D.; Burgett, W.; Carter, H.

    1994-01-01

    The SSCL Accelerator System's String Test (ASST) has had several cool down, subsequent operational test series, and warm up cycles. The first cycle of these was rather limited in scope as mandated by Congress. The subsequent tests have been performed to obtain more complete information about parameters of, or operating experience with, the ensemble of magnets and spools when operating serially as in accelerator operations. The tests and procedures performed to date have emphasized cryogenic, mechanical, and electrical operations. These have included running, as well as upset conditions, i.e., superconducting to normal transition of the string (quench). This paper represents a summary of the operational test results and characteristics seen to date. A limited discussion will be included as to their implications with respect to a successful accelerator operation

  7. MRI characteristics of torn and untorn post-operative menisci

    Kijowski, Richard; Rosas, Humberto; Liu, Fang [University of Wisconsin School of Medicine and Public Health, Department of Radiology, Madison, WI (United States); Williams, Adam [Radiology and Imaging Consultants, Colorado Springs (United States)

    2017-10-15

    To compare magnetic resonance imaging (MRI) characteristics of torn and untorn post-operative menisci. The study group consisted of 140 patients with 148 partially resected menisci who were evaluated with a repeat knee MRI examination and subsequent repeat arthroscopic knee surgery. Two musculoskeletal radiologists retrospectively assessed the following MRI characteristics of the post-operative meniscus: contour (smooth or irregular), T2 line through the meniscus (no line, intermediate signal line, intermediate-to-high signal line, and high fluid-like signal line), displaced meniscus fragment, and change in signal pattern through the meniscus compared with baseline MRI. Positive predictive values (PPV) and negative predictive values (NPV) were calculated using arthroscopy as the reference standard. All 36 post-operative menisci with no T2 line were untorn at surgery (100% NPV), whereas 46 of the 79 post-operative menisci with intermediate T2 line, 16 of the 18 post-operative menisci with intermediate-to-high T2 line, and 14 of the 15 post-operative menisci with high T2 line were torn at surgery (58.2%, 88.9%, and 93.3% PPV respectively). Additional MRI characteristics associated with torn post-operative meniscus at surgery were irregular meniscus contour (PPV 85.7%), displaced meniscus fragment (PPV 100%), and change in signal pattern through the meniscus (PPV 99.4%). Post-operative menisci with no T2 signal line were untorn at surgery. The most useful MRI characteristics for predicting torn post-operative menisci at surgery were change in signal pattern through the meniscus compared with baseline MRI, and displaced meniscus fragment followed by high T2 line through the meniscus, intermediate-to-high T2 line through the meniscus, and irregular meniscus contour. (orig.)

  8. MRI characteristics of torn and untorn post-operative menisci

    Kijowski, Richard; Rosas, Humberto; Liu, Fang; Williams, Adam

    2017-01-01

    To compare magnetic resonance imaging (MRI) characteristics of torn and untorn post-operative menisci. The study group consisted of 140 patients with 148 partially resected menisci who were evaluated with a repeat knee MRI examination and subsequent repeat arthroscopic knee surgery. Two musculoskeletal radiologists retrospectively assessed the following MRI characteristics of the post-operative meniscus: contour (smooth or irregular), T2 line through the meniscus (no line, intermediate signal line, intermediate-to-high signal line, and high fluid-like signal line), displaced meniscus fragment, and change in signal pattern through the meniscus compared with baseline MRI. Positive predictive values (PPV) and negative predictive values (NPV) were calculated using arthroscopy as the reference standard. All 36 post-operative menisci with no T2 line were untorn at surgery (100% NPV), whereas 46 of the 79 post-operative menisci with intermediate T2 line, 16 of the 18 post-operative menisci with intermediate-to-high T2 line, and 14 of the 15 post-operative menisci with high T2 line were torn at surgery (58.2%, 88.9%, and 93.3% PPV respectively). Additional MRI characteristics associated with torn post-operative meniscus at surgery were irregular meniscus contour (PPV 85.7%), displaced meniscus fragment (PPV 100%), and change in signal pattern through the meniscus (PPV 99.4%). Post-operative menisci with no T2 signal line were untorn at surgery. The most useful MRI characteristics for predicting torn post-operative menisci at surgery were change in signal pattern through the meniscus compared with baseline MRI, and displaced meniscus fragment followed by high T2 line through the meniscus, intermediate-to-high T2 line through the meniscus, and irregular meniscus contour. (orig.)

  9. Numerical study of some operating characteristics for argon induction plasmas

    Ebihara, K.

    1978-01-01

    Some operating characteristics of argon induction plasmas at atmospheric pressure were obtained numerically by using magnetohydrodynamic equations. From these characteristics we can estimate the general dependency of plasma temperatures on operating conditions for induction plasmas. Calculated relationships between the sustaining electric field strength at the plasma surface and the electric power input show the existence of a minimum value of the field strength, the reason for which is revealed by detailed investigation of the calculated radial temperature distributions. Further, it was found that the minimum increases almost linearly with increasing frequency. In addition, characteristics of the Poynting vector and heat conduction loss at the plasma surface were obtained. Some characteristics obtained here give practical information on the electromagnetic field which is necessary to maintain the steady plasmas

  10. A study on the operator's communication pattern characteristics under abnormal operating situation of nuclear power plants

    Kim, S. H.; Park, J.

    2008-01-01

    The quality of a probabilistic safety assessment (PSA) has become more important and a human reliability analysis (HRA) is known as a major contributor to the uncertainty of a PSA. As a part of enhancing the HRA quality, a study was initiated to find out characteristics of communication pattern and to evaluate communication quality of the operators of nuclear power plants. Korea Atomic Energy Research Institute (KAERI) is developing evaluation methods for the effect of human-induced events on risk/performance. This paper describes a study on the operator's communication pattern characteristics under abnormal operating situation of nuclear power plants. The study was carried out in four stages; 1) Video recording 2) Audio scripting 3) Message Classification 4) Communication Pattern Analysis. We recorded eight abnormal simulator training programs from Younggwang nuclear power plant training center. After that we performed message classification and carried out communication pattern analysis. We compared communication patterns of abnormal operating situation with emergency operating situation.As results of analysis, the role of SRO (senior reactor operator) under abnormal operating situation was decreased than the activities under emergency operating situation because each operator (reactor operator, turbine operator, safety supervisor) in main control room (MCR) performs the activity to control by himself with corresponding field engineers with his basic knowledge of the system. On the other hand, the operator's decision making processes and activities under abnormal operating situation were dramatically increased than the emergency operating situation. (authors)

  11. Logistic Regression Analysis of Operational Errors and Routine Operations Using Sector Characteristics

    Pfleiderer, Elaine M; Scroggins, Cheryl L; Manning, Carol A

    2009-01-01

    Two separate logistic regression analyses were conducted for low- and high-altitude sectors to determine whether a set of dynamic sector characteristics variables could reliably discriminate between operational error (OE...

  12. Design features and operating characteristics of the MC-50 cyclotron

    Bak, Hae Ill; Bak, Joo Shik

    1989-01-01

    The MC-50 cyclotron at Korean Cancer Center Hospital is now operational for neutron therapy and medical radioisotope production. Design features, mechanical structures and operating characteristics of the MC-50 are described in this paper. Optimum operating condition for this cyclotron has been determined by the repetitive running, and the performances of the internal beam have been investigated through the measurements of intensity and spatial distribution of the internal beam as a function of the radius of the cyclotron. Routinely, the 40 μA of 50 MeV protons have been obtained at first Faraday cup with a extraction efficiency of 61%. (Author)

  13. Post operation: The changing characteristics of nuclear fuel cycle costs

    Frank, F.J.

    1986-01-01

    Fundamental changes have occurred in the nuclear fuel cycle. These changes forged by market forces, legislative action, and regulatory climate appear to be a long term characteristic of the nuclear fuel cycle. The nature of these changes and the resulting emerging importance of post-operation and its impact on fuel cycle costs are examined

  14. Receiver Operating Characteristics (ROCs) in Recognition Memory: A Review

    Yonelinas, Andrew P.; Parks, Colleen M.

    2007-01-01

    Receiver operating characteristic (ROC) analysis is being used increasingly to examine the memory processes underlying recognition memory. The authors discuss the methodological issues involved in conducting and analyzing ROC results, describe the various models that have been developed to account for these results, review the behavioral empirical…

  15. OPERATION MODES AND CHARACTERISTICS OF PLASMA DIPOLE ANTENNA

    Nikolay Nikolaevich Bogachev

    2014-02-01

    Full Text Available Existence modes of  surface electromagnetic wave on a plasma cylinder, operating modes and characteristics of the plasma antenna were studied in this paper. Solutions of the dispersion equation of surface wave were obtained for a plasma cylinder with finite radius for different plasma density values. Operation modes of the plasma asymmetric dipole antenna with finite length and radius were researched by numerical simulation. The electric field distributions of  the plasma antenna in near antenna field and the radiation pattern were obtained. These characteristics were compared to characteristics of the similar metal antenna. Numerical models verification was carried out by comparing of the counted and measured metal antenna radiation patterns.

  16. 49 CFR 234.205 - Operating characteristics of warning system apparatus.

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Operating characteristics of warning system... characteristics of warning system apparatus. Operating characteristics of electromagnetic, electronic, or... limits within which the system is designed to operate. ...

  17. The characteristics of operation of the Shatlyk gas condensate deposit

    Zatov, G.A.; Friman, Yu.M.; Frumson, Yu.V.; Koshayev, T.K.; Stepanov, N.G.; Tverkovkin, S.M.

    1983-01-01

    Results are correlated of the operation of the Shatlyksk deposit for a 10 year period from the start of its development through 1982. The rates of gas withdrawal from the deposits are analyzed, along with the conditions for manifestation of elastic, water thrust modes, the characteristics of the studied wells and other issues. The results of modeling the advancement of stratum waters are cited. The modeling was performed on a computer (EVM) using a system of two dimensional, two phase filtration.

  18. Classification of operational characteristics of commercial cup-anemometers

    Friis Pedersen, T; Schmidt Paulsen, U [Risoe National Lab., Wind Energy and Atmospheric Physics Dept., Roskilde (Denmark)

    1999-03-01

    The present classification of cup-anemometers is based on a procedure for classification of operational characteristics of cup-anemometers that was proposed at the EWEC `97 conference in Dublin 1997. Three definitions of wind speed are considered. The average longitudinal wind speed (ID), the average horizontal wind speed (2D) and the average vector wind speed (3D). The classification is provided in these terms, and additionally, the turbulence intensities, which are defined from the same wind speed definitions. The commercial cup-anemometers have all been calibrated in wind tunnel for the normal calibrations and angular characteristics. Friction was measured by blywheel testing, where the surrounding temperatures were varied over a wide range. The characteristics of the cup-anemometers have been fitted to the heuristic dynamic model, and the response has been calculated in time domain for prescribed ranges of external operational conditions. The results are presented in ranges of maximum deviations of `measured` average wind speed. For each definition of wind speed and turbulence intensity, the cup-anemometers are ranked according to the most precise instrument. Finally, the most important systematic error sources are commented. (au)

  19. Operational characteristics of the CALIBAN fast pulse reactor

    Cortella, J.; Reberol, R.; Vanel, M.

    1976-01-01

    CALIBAN is a FPR operated at CEA-Valduc Center since 1971. It has been designed as a fast neutron irradiation source and its environment is specific for this utilization. To date, it delivered more than 400 bursts and the fuel integrated about 5.10 19 fissions. The main characteristics are: - cylindirical core 113 kg U 235 - Mo 10% alloy - integrated dose in a burst in the central 2.5cm diam cavity:3.10 14 n.cm -2 - integrated dose in a burst outside of the core:5.10 13 n.cm -2 - pulse width:50μs A special effort was made in measuring the spectrometric and dosimetric neutron and gamma characteristics. Some results will be presented here. (auth.)

  20. Analysis for RSG-GAS operational characteristics of reactor cooling system

    Nurhappy, T.

    1998-01-01

    Analysis of operational characteristics of reactor cooling systems (JE01 and PA) is aimed at determining the effects of operation and maintenance patterns to the operational characteristic of the system. Analysis is carried out by virtue of the operating and maintenance data from 1987 to 1997, comprising the operating hours (duration) and data on operating failures of the systems. Results of study show that, either separately or jointly, the operating and maintenance patterns will qualitatively affect the operational characteristic of the systems

  1. Operational characteristics of the VEC radio-frequency system

    Khemka, P K; Basu Mallik, D N; Bhattacharya, D S; Mukherjee, A K; Mukherjee, B; Ramamurthy, S S [Bhabha Atomic Research Centre, Bombay (India). Variable Energy Cyclotron Project

    1979-01-01

    The operating characteristics of the 400 kW rf system of the VEC, based on the RCA 6949 oscillator tube, and covering a frequency range of 5.5 to 16.5 MHz, are described. The frequency stability of the system is measured to be 1 part in 10/sup 5/, and a dee voltage of 40 kV at 8 MHz has been achieved. The results of experimental adjustments of ratio capacitor for proper excitation and appropriate fixed dee voltage over the entire frequency range are discussed. An analysis of the multi-pactoring encountered during beam trials is presented.

  2. Operational characteristics of the VEC radio frequency system

    Khemka, P.K.; Basu Mallik, D.N.; Bhattacharya, D.S.; Mukherjee, A.K.; Mukherjee, B.; Ramamurthy, S.S.

    1979-01-01

    The operating characteristics of the 400 KW RF system of the VEC, based on the RCA 6949 oscillator tube, and covering a frequency range of 5.5 to 16.5 MHZ, are described. The frequency stability of the system is measured to be 1 part in 10 5 , and a dee voltage of 40 kV at 8 MHZ has been achieved. The results of experimental adjustments of ratio capacitor for proper excitation and appropriate fixed dee voltage over the entire frequency range are discussed. An analysis of the multi-pactoring encountered during beam trials is presented. (auth.)

  3. Cauchy problem for differential operators with double characteristics non-effectively hyperbolic characteristics

    Nishitani, Tatsuo

    2017-01-01

    Combining geometrical and microlocal tools, this monograph gives detailed proofs of many well/ill-posed results related to the Cauchy problem for differential operators with non-effectively hyperbolic double characteristics. Previously scattered over numerous different publications, the results are presented from the viewpoint that the Hamilton map and the geometry of bicharacteristics completely characterizes the well/ill-posedness of the Cauchy problem. A doubly characteristic point of a differential operator P of order m (i.e. one where Pm = dPm = 0) is effectively hyperbolic if the Hamilton map FPm has real non-zero eigenvalues. When the characteristics are at most double and every double characteristic is effectively hyperbolic, the Cauchy problem for P can be solved for arbitrary lower order terms. If there is a non-effectively hyperbolic characteristic, solvability requires the subprincipal symbol of P to lie between − Pµj and P µj , where iµj are the positive imaginary eigenvalues of FPm ....

  4. A Three-Dimensional Receiver Operator Characteristic Surface Diagnostic Metric

    Simon, Donald L.

    2011-01-01

    Receiver Operator Characteristic (ROC) curves are commonly applied as metrics for quantifying the performance of binary fault detection systems. An ROC curve provides a visual representation of a detection system s True Positive Rate versus False Positive Rate sensitivity as the detection threshold is varied. The area under the curve provides a measure of fault detection performance independent of the applied detection threshold. While the standard ROC curve is well suited for quantifying binary fault detection performance, it is not suitable for quantifying the classification performance of multi-fault classification problems. Furthermore, it does not provide a measure of diagnostic latency. To address these shortcomings, a novel three-dimensional receiver operator characteristic (3D ROC) surface metric has been developed. This is done by generating and applying two separate curves: the standard ROC curve reflecting fault detection performance, and a second curve reflecting fault classification performance. A third dimension, diagnostic latency, is added giving rise to 3D ROC surfaces. Applying numerical integration techniques, the volumes under and between the surfaces are calculated to produce metrics of the diagnostic system s detection and classification performance. This paper will describe the 3D ROC surface metric in detail, and present an example of its application for quantifying the performance of aircraft engine gas path diagnostic methods. Metric limitations and potential enhancements are also discussed

  5. Human dynamics scaling characteristics for aerial inbound logistics operation

    Wang, Qing; Guo, Jin-Li

    2010-05-01

    In recent years, the study of power-law scaling characteristics of real-life networks has attracted much interest from scholars; it deviates from the Poisson process. In this paper, we take the whole process of aerial inbound operation in a logistics company as the empirical object. The main aim of this work is to study the statistical scaling characteristics of the task-restricted work patterns. We found that the statistical variables have the scaling characteristics of unimodal distribution with a power-law tail in five statistical distributions - that is to say, there obviously exists a peak in each distribution, the shape of the left part closes to a Poisson distribution, and the right part has a heavy-tailed scaling statistics. Furthermore, to our surprise, there is only one distribution where the right parts can be approximated by the power-law form with exponent α=1.50. Others are bigger than 1.50 (three of four are about 2.50, one of four is about 3.00). We then obtain two inferences based on these empirical results: first, the human behaviors probably both close to the Poisson statistics and power-law distributions on certain levels, and the human-computer interaction behaviors may be the most common in the logistics operational areas, even in the whole task-restricted work pattern areas. Second, the hypothesis in Vázquez et al. (2006) [A. Vázquez, J. G. Oliveira, Z. Dezsö, K.-I. Goh, I. Kondor, A.-L. Barabási. Modeling burst and heavy tails in human dynamics, Phys. Rev. E 73 (2006) 036127] is probably not sufficient; it claimed that human dynamics can be classified as two discrete university classes. There may be a new human dynamics mechanism that is different from the classical Barabási models.

  6. Acquisition of Human Operation Characteristics for Kite-based Tethered Flying Robot using Human Operation Data

    Todoroki, Chiaki; Takahashi, Yasutake; Nakamura, Takayuki

    2015-01-01

    This paper shows human skill acquisition systems to control the kite-based tethered flying robot. The kite-based tethered flying robot has been proposed as a flying observation system with long-term activity capability[1]. It is a relatively new system and aimed to complement other information gathering systems using a balloon or an air vehicle. This paper shows some approaches of human operation characteristics acquisition based on fuzzy learning controller, knearest neighbor algorithm, and ...

  7. Characteristics of Subfreezing Operation of Polymer Electrolyte Membrane Fuel Cells

    Mishler, Jeffrey Harris

    validated against experimental data. The ice coverage coefficient was shown to be a key variable in matching with experimental data. From model analysis, it appears that the coulombs of charge passed before operation failure is an important parameter characterizing PEM fuel cell cold start. To investigate the coulombs of charge and its determining factors, PEM fuel cells were constructed to measure the effects of membrane configuration (thickness and initial state), catalyst layer configuration (thickness and ionomer-carbon ratio), current density, and temperature on the quantity. It was found that subfreezing temperature, ionomer-catalyst ratio, and catalyst-layer thickness significantly affect the amount of charge transferred before operational failure, whereas the membrane thickness and initial hydration level have limited effect for the considered cases. In addition, degradation of the catalyst layer was observed and quantified. These results improve the fundamental understanding of characteristics of subfreezing operation and thus are valuable for automobile applications of PEM fuel cells. The model directly relates the material properties to voltage loss, and predicts voltage evolution, thus providing a way for material optimization and diagnostics. Additionally, insights into component design and operating conditions can be used to better optimize the fuel cell for cold start-up of the vehicle.

  8. Receiver Operating Characteristic Analysis for Detecting Explosives-related Threats

    Oxley, Mark E; Venzin, Alexander M

    2012-11-14

    The Department of Homeland Security (DHS) and the Transportation Security Administration (TSA) are interested in developing a standardized testing procedure for determining the performance of candidate detection systems. This document outlines a potential method for judging detection system performance as well as determining if combining the information from a legacy system with a new system can signicantly improve performance. In this document, performance corresponds to the Neyman-Pearson criterion applied to the Receiver Operating Characteristic (ROC) curves of the detection systems in question. A simulation was developed to investigate how the amount of data provided by the vendor in the form of the ROC curve eects the performance of the combined detection system. Furthermore, the simulation also takes into account the potential eects of correlation and how this information can also impact the performance of the combined system.

  9. ANALYSIS OF THE OPERATIONAL CHARACTERISTICS OF DIESEL-ELECTRIC LOCOMOTIVES

    L. V. Ursulyak

    2014-12-01

    Full Text Available Purpose. To compare the operational characteristics of freight diesel-electric locomotives ER20CF and 2М62м, which are operated with Lithuanian Railways. Important problems on traction calculations are considered in this article. In this article the critical tasks of traction calculations are solved. It is the main computational tool in the rational functioning, planning and development of railways: determination of the estimated weight of the rolling stock, the diagrams construction of specific resultant forces of a train, the permitted speed definition of the train on the slopes, curves of train traffic construction on the section. Methodology. Using the rules and methods of traction calculations the analysis of the basic operational characteristics of the modernized freight diesel-electric locomotive 2М62m and freight passenger dual locomotive 2ER20CF was held. The maximum weight of the train set, the track structure on a high-speed ascent through the use of kinetic energy (with traction and without traction, technical speed, acceleration force and the value of the smallest radius curve are selected as controlled parameters. During the calculations it was considered that the trains were formed of a fully loaded four-axle gondola cars, model 112-119 (feature-606 with axle load of 23.5 t; the motion was carried out on the continuous welded rail track; the front of the train set is a dual locomotive 2ER20CF or two locomotive 2М62м. Longitudinal profile of the road on the route Vilnus–KlF was analyzed for the choice of theoretical rise. Inspection concerning the possibility of overcoming the high-speed rise was performed with an analytical method, based on the use of the kinetic energy accumulated by the overcoming of «light» elements of the profile. Findings. In the calculations, the maximum weight of the train set taking into account theoretical rise was analyzed. The inspection of the theoretical weight of the train set on a reliable

  10. Pseudo-spark switch (PSS) characteristics under different operation conditions

    Hamad, B. H., E-mail: dr.bassmahussain@gmail.com; Ahmad, A. K., E-mail: ahmad.kamal@sc.nahrainuniv.edu.iq [College of Science, Al Nahrain University, Jadria, Baghdad (Iraq); Lateef, K. H., E-mail: kamalhlatif@yahoo.com [Ministry of Science and Technology, Jadria, Baghdad (Iraq)

    2016-08-15

    The present paper concentrates on the characteristics of the pseudospark switch (PSS) designed in a previous work. The special characteristics of PSS make it a replacement for other high voltage switches such as thyratrons and ordinary high-pressure spark gaps. PSS is characterized by short rise time and small jitter time. The pseudo park chamber consists of two hollow cylindrical electrodes made of a stainless steel material (type 306L) separated by an insulator. The insulator used in our design is a glazed ceramic 70 mm in diameter and 3.5 mm in thickness. A PSS with an anode voltage of 29.2 kV, and a current of 3.6 kA and 11 ns rise time was achieved and used successfully at a repetition rate of about 2.2 kHz. A simple trigger circuit designed, built, and used effectively reaching more than 1.56 kV trigger pulse which is sufficient to ignite the argon gas inside the cathode to cause a breakdown. A non-inductive dummy load is designed to be a new technique to find the accurate value of the PSS inductance. A jitter time of ±10 ns pulses is observed to occur in a reliable manner for more than 6 h of continuous operation. In this research, the important parameters of this switch like rise time, peak current, and anode voltage were studied at various values of charging capacitance. The lifetime of this system is depending on the kind of the electrode material and on the type of insulation material in the main gap of the pseudospark switch.

  11. [Characteristics of the Chinese human milk banks' operation].

    2017-08-02

    Objective: To assess the operation status of human milk banks in the mainland of China. Method: This retrospective study included a consecutive series of 14 human milk banks in the mainland of China from March 2013 to December 2016. The opened date, condition of donated breast milk, characteristics of donors and clinical application of donated breast milk were analyzed. Result: There were 14 human milk banks successively founded in mainland China from March 2013 to December 2016. The number of human milk banks, the amount of donated breast milk, the number of eligible donors and the times of donation had increased each year. Howere, the operation status among these milk banks varied greatly. Among them, one human milk bank has newly opened without relevant data, 6 banks could accept frozen breast milk, and the remaining 7 banks could only collect breast milk by the nurses in the bank. Among the 3 121 eligible donors, 1 404 (45.0%) donated less than 3 times, 2 553 (81.8%) aged 25 to 35 years, 2 828 (90.6%) had term delivery, 2 409 (77.2%) began donation one month after birth, 1 798 (57.6%) were company employees and housewives and 1 891 (60.6%) had bachelor or higher degree. The use of donor breast milk, the number of recipients and the average received amount of breast milk every person varied greatly among these banks. Conclusion: The human milk banking developed quickly in the mainland of China. Howere, the number of donors and the amount of donated breast milk which could not meet the clinical demands should be improved. And it was urgent to establish the standards or guidelines of the human milk banking as soon as possible in China.

  12. Evaluation of the operational characteristics of a CT ionization chamber

    Maia, Ana F.; Caldas, Linda V.E.

    2006-01-01

    The most common ionization chamber used in computed tomography dosimetry is the 'pencil ionization chamber'. It is a special cylindrical dosimeter developed for attending computed tomography beams particularities. In this study, a Victoreen pencil ionization chamber was submitted to a set of tests for a detailed evaluation of its operational characteristics. Such as many kinds of detectors, especially field instruments, this ionization chamber had originally a preamplifier to keep it electrically more stable. In this study, the performance of the chamber was analyzed with the original preamplifier and after its removal, and the results were compared. The objective of the preamplifier removal was to enable connecting the chamber to other kinds of electrometers available in laboratories. The behavior of the pencil ionization chamber before and after the removal of the preamplifier was very similar, and the results obtained were always within the limits of international recommendations. The results obtained in both situations allow, if necessary, the preamplifier removal of the system without lack of precision in the measurements

  13. Receiver operating characteristic analysis improves diagnosis by radionuclide ventriculography

    Dickinson, C.Z.; Forman, M.B.; Vaugh, W.K.; Sandler, M.P.; Kronenberg, M.W.

    1985-01-01

    Receiver operating characteristic analysis (ROC) evaluates continuous variables to define diagnostic criteria for the optimal sensitivity (SENS) and specificity (SPEC) of a test. The authors studied exercise-induced chest pain (CP), ST-changes on electrocardiography (ECG) and rest-exercise gated radionuclide ventriculography (RVG) using ROC to clarify the optimal criteria for detecting myocardial ischemia due to coronary artherosclerosis (CAD). The data of 95 consecutive patients studied with coronary angiography, rest-exercise RVG and ECG were reviewed. 77 patients had ''significant'' CAD (≥50% lesions). Exercise-induced CP, ECG abnormalities (ST-T shifts) and RVG abnormalities (change in ejection fraction, 2-view regional wall motion change and relative end-systolic volume) were evaluated to define optimal SENS/SPEC of each and for the combined data. ROC curves were constructed by multiple logistic regression (MLR). By MLR, RVG alone was superior to ECG and CP. The combination of all three produced the best ROC curve for the entire group and for clinical subsets based on the number of diseased vessels and the presence or absence of prior myocardial infarction. When CP, ECG and RVG were combined, the optimal SENS/SPEC for detection of single vessel disease was 88/86. The SENS/SPEC for 3 vessel disease was 93/95. Thus, the application of RVG for the diagnosis of myocardial ischemia is improved with the inclusion of ECG and CP data by the use of a multiple logistic regression model. ROC analysis allows clinical application of multiple data for diagnosing CAD at desired SENS/SPEC rather than by arbitrary single-standard criteria

  14. Research about reactor operator's personability characteristics and performance

    Wei Li; He Xuhong; Zhao Bingquan [Tsinghua Univ., Institute of Nuclear Energy Technology, Beijing (China)

    2003-03-01

    To predict and evaluate the reactor operator's performance by personality characteristics is an important part of reactor operator safety assessment. Using related psychological theory combined with the Chinese operator's fact and considering the effect of environmental factors to personality analysis, paper does the research about the about the relationships between reactor operator's performance and personality characteristics, and offers the reference for operator's selection, using and performance in the future. (author)

  15. Psychological characteristics of licensed nuclear power plant operators

    Sajwaj, T.; Ford, T.; McGee, R.K.

    1987-01-01

    The safe production of electricity by nuclear power plants has been the focus of considerable attention. Much of this concern has been focused on equipment and procedural issues, with less attention to the psychological factors that affect the operations staff of the plants, i.e., those individuals who are most directly responsible for a plant's operations. Stress and type A qualities would be significant for these individuals because of their relationships to job performance and health. Of equal significance would be work-related factors, such as job involvement and work pressure. Also of interest would be hostile tendencies because of the need for cooperation and communications among operations staff. Two variables could influence these psychological factors. One is the degree of responsibility for a plant's nuclear reactors. The individuals with the greatest responsibility are licensed by the US Nuclear Regulatory Commission (NRC). There are also individuals with less direct responsibilities who are not licensed. A second variable is the operating status of the plant, whether or not the plant is currently producing electricity. Relative to ensuring the safe operation of nuclear power plants, these data suggest a positive view of licensed operators. Of interest are the greater stress scores in the licensed staff of the operating plant in contrast with their peers in the nonoperating plant

  16. Characteristics of paddy operations with biodiesel fuelled tractor

    Kim, Y.; Park, S.H.; Kim, C.K.; Im, D.H.; Kim, H.J.; Chung, S.C. [National Academy of Agricultural Science, Seodundong, Suwon (Korea, Democratic People' s Republic of); Kim, S.S. [Daedong Industrial Co., Chang Nyong-Kun, Kyungnam (Korea, Democratic People' s Republic of)

    2010-07-01

    This paper reported on a study in which biofuels were tested for their power and competitiveness in various paddy operations, such as plowing and rotary tilling of paddy fields. The study considered the use of diesel fuel as well as 20 per cent biodiesel (BD20) and 100 per cent biodiesel (BD100) as an alternative fuel for tractors. Ignition problems or abrupt stopping were not monitored during operations of plowing, rotary tilling and travelling on the road. According to tractor power take-off (PTO) test codes, there was no considerable power difference between the 3 fuels. However, fuel consumption rates were quite different between the biodiesels and diesel fuel in the paddy works. Fuel consumption increased when biodiesel content increased. Approximately 35 to 40 per cent more fuel was needed for rotary tilling operations than plowing operations. Within the operations, the maximum difference occurred during the rotary tilling of wet paddy fields. This difference was as high as 20 per cent , between BD100 and diesel fuel. In terms of exhaust gases, more carbon dioxide was discharged from diesel fuel than biodiesels, but more nitrous oxide was discharged with biodiesels. It was difficult to differentiate quantities of carbon monoxide between the 3 different fuels.

  17. Operation characteristics and conditions of training reactor VR-1

    Matejka, K.; Kolros, A.; Polach, S.; Sklenka, L.

    1994-01-01

    The first 3 years of operation of the VR-1 training reactor are reviewed. This period includes its physical start-up (preparation, implementation, results) and operation development as far as the current operating configuration of the reactor core. The physical start-up was commenced using a reactor core referred to as AZ A1, whose physical parameters had been verified by calculation and whose configuration was based on data tested experimentally on the SR-0 reactor at Vochov. The next operating core, labelled AZ A2, was already prepared during the test operation of the VR-1 reactor. Its configuration was such that both of the main horizontal channels, radial and tangential, could be employed. The configuration that followed, AZ A3, was an intermediate step before testing the graphite side reflector. The current reactor core, labelled AZ A3 G, was obtained by supplementing the previous core with a one-sided graphite side reflector. (Z.S.). 2 tabs., 11 figs., 2 refs

  18. Wavelet and receiver operating characteristic analysis of heart rate variability

    McCaffery, G.; Griffith, T. M.; Naka, K.; Frennaux, M. P.; Matthai, C. C.

    2002-02-01

    Multiresolution wavelet analysis has been used to study the heart rate variability in two classes of patients with different pathological conditions. The scale dependent measure of Thurner et al. was found to be statistically significant in discriminating patients suffering from hypercardiomyopathy from a control set of normal subjects. We have performed Receiver Operating Characteristc (ROC) analysis and found the ROC area to be a useful measure by which to label the significance of the discrimination, as well as to describe the severity of heart dysfunction.

  19. Characteristics of a high current ion source operated with lithium

    Bay, H.L.; Dullni, E.; Leismann, P.

    1986-05-01

    A low pressure arc ion source has been tested for operation with lithium. Currents up to 120 mA could be extracted through a multiple aperture extraction system at energies of 30 keV. The ion beam was neutralized up to 70% in a charge exchange cell filled with lithium vapour. The beam divergence ranged from 20 to 25 mrad full angle deduced from the spatial distribution of the collision induced Li I resonance line. Current densities from 2 to 3 mA/m 2 at a distance of 1.9 m from the source were measured either by laser induced fluorescence or with a Faraday cup. (orig.)

  20. Operational characteristics, strategies and performance of foreign and demestic banks in India

    Keshari, Pradeep Kumar

    2013-01-01

    This paper has tried to examine the relative characteristics and performance of foreign and domestic banks operating in India. A comparison of their characteristics undoubtedly suggest that foreign banks as a group differ significantly from domestic banks. It was also found that foreign banks enjoyed higher profitability than the domestic banks. The higher profitability of the former was a reflection of their particular operational characteristics, strategies and the favourable attitude of t...

  1. Operational characteristics optimization of human-computer system

    Zulquernain Mallick

    2010-09-01

    Full Text Available Computer operational parameters are having vital influence on the operators efficiency from readability viewpoint. Four parameters namely font, text/background color, viewing angle and viewing distance are analyzed. The text reading task, in the form of English text, was presented on the computer screen to the participating subjects and their performance, measured in terms of number of words read per minute (NWRPM, was recorded. For the purpose of optimization, the Taguchi method is used to find the optimal parameters to maximize operators’ efficiency for performing readability task. Two levels of each parameter have been considered in this study. An orthogonal array, the signal-to-noise (S/N ratio and the analysis of variance (ANOVA were employed to investigate the operators’ performance/efficiency. Results showed that Times Roman font, black text on white background, 40 degree viewing angle and 60 cm viewing distance, the subjects were quite comfortable, efficient and read maximum number of words per minute. Text/background color was dominant parameter with a percentage contribution of 76.18% towards the laid down objective followed by font type at 18.17%, viewing distance 7.04% and viewing angle 0.58%. Experimental results are provided to confirm the effectiveness of this approach.

  2. Operational features and microwave characteristics of the Vircator II experiment

    Price, D.; Fittinghoff, O.; Benford, J.; Sze, H.; Woo, W.

    1988-01-01

    The Vircator II oscillating virtual-cathode microwave source operates with diode voltages between 600 and 800 kV and diode current between 50 and 120 kA. Maximal microwave output power between 200 and 500 MW is achieved when the diode aspect ratio, cathode surface, charge voltage, and extraction coupling are arranged to simultaneously 1) maximize diode voltage, 2) satisfy magnetic insulation criteria, 3) avoid nonuniform or unstable electron emission, and 4) optimize microwave transmission from the virtual cathode to the launching antenna. Broad-band radiation between 0.4 and 5.5 GHz is generated. The central frequency follows the beam plasma frequency. It is tuned by varying the current density with anode-cathode (A-K) gap adjustments

  3. WIND TURBINE OPERATION PARAMETER CHARACTERISTICS AT A GIVEN WIND SPEED

    Zdzisław Kamiński

    2014-06-01

    Full Text Available This paper discusses the results of the CFD simulation of the flow around Vertical Axis Wind Turbine rotor. The examined rotor was designed following patent application no. 402214. The turbine operation is characterised by parameters, such as opening angle of blades, power, torque, rotational velocity at a given wind velocity. Those parameters have an impact on the performance of entire assembly. The distribution of forces acting on the working surfaces in the turbine can change, depending on the angle of rotor rotation. Moreover, the resultant force derived from the force acting on the oncoming and leaving blades should be as high as possible. Accordingly, those parameters were individually simulated over time for each blade in three complete rotations. The attempts to improve the performance of the entire system resulted in a new research trend to improve the performance of working turbine rotor blades.

  4. Experimental investigation of the operating characteristic of a plasma focus

    Rapp, H.

    The design of a 60 kJ plasma focus installation of the Mather type for generating a deuterium plasma with fusion conditions is described. The advantages of a plasma focus layout in comparison with the linear z-pinch are explained, and questions which arise from the interaction of energy storage and plasma accelerator are discussed. The conclusions are used as a basis for planning the entire installation and dimensioning the individual components. This is followed by a description of some typical difficulties which can have a negative effect on the operation of the plasma focus and how these problems were overcome. Photographic observation of the acceleration and compression process has provided important information concerning the configuration, structure and velocity of the plasma, which is supplemented by magnetic probe measurements of the variations in current. Additional observations involve measurements of neutron yield, neutron flux anisotropy and the neutron spectrum. A theoretical analysis is also presented

  5. Operational Characteristics of Four Commercially Available Personal Cooling Vests

    Ku, Yu-Tsuan E.; Montgomery, Leslie D.; Lee, Hank C.; Webbon, Bruce W.; Kliss, Mark (Technical Monitor)

    1997-01-01

    Personal thermoregulatory systems which provide chest cooling are used in the industrial and aerospace environments to alleviate thermal stress. However, little information is available regarding the physiologic and circulatory changes produced by routine operation of these systems. The objectives of this study were to compare the effectiveness of two passive and two active cooling vests, and to measure the body temperature and circulatory changes produced by each cooling vest configuration. The MicroClimate Systems and the Life Enhancement Tech(LET) lightweight liquid cooling vests, the Steele Vest and LET's Zipper Front Garment were used to cool the chest region of 11 male and 10 female subjects (25 to 55 yr.) in this study. Calf, forearm and finger blood flows were measured using a tetrapolar impedance rheograph. The subjects, seated in an upright position at normal room temperature (approx.21 C), were tested for 60 min. with the cooling system operated at its maximum cooling capacity. Blood flows were recorded continuously using a computer data acquisition system with a sampling frequency of 250 Hz. Oral, right and left ear temperatures and cooling system parameters were logged manually every 5 min. Arm, leg, chest and rectal temperatures; heart rate; respiration; and an activity index were recorded continuously on a URI Inc. Biolog ambulatory monitor. In general, the male and female subjects' rectal and ear temperature responses to cooling were similar for all vest configurations tested. Oral temperatures during the recovery period were significantly (Pcooling and recovery periods. These results show that all vest configurations elicit a similar thermal response in both male and female subject groups. However, subject population variance was rather large and may have masked differences between the vests. One vest may prove more effective than another for a given individual, and experience is the only means of determining this.

  6. Operating characteristics of the Columbia University α-μ beam

    Randers-Pehrson, G.

    1994-01-01

    The authors have constructed and are now operating an external alpha particle microbeam in a single ion mode for the study of radiation damage to living mammalian cells. Their objective is to understand the biological effects of radon-daughter exposures in the environment. The alpha particle beam is produced by accelerating helium ions with a 4.2 MV Van de Graaff. The beam is directed vertically through the floor of a biology laboratory and into a vibration-isolated microscope. The beam is collimated to a diameter of 6 micrometers by a pair of laser-drilled apertures mounted on a goniometric alignment fixture immediately below the microscope stage. A laser beam used to optically locate the beam also passes through the apertures. Cells growing on thin-bottomed petri dishes are treated with a nuclear stain and illuminated with UV light. The cell nuclei are observed with a microscope fitted with an image intensifier and CCD camera which feeds a PC-based frame grabber and commercial video analysis system. The analysis program is used to locate cellnuclei on the culture dish and then to communicate with an in-house program that controls the microscope stage. This latter program visits each cell in turn and, after final positioning by the operator using a joy stick, a chosen small number of alpha particles are allowed to penetrate the cell nucleus. The alpha particles are detected after passing through the cells by a gas proportional counter mounted on the microscope objective. Observation of the cells and the irradiation are simultaneous. The system presently requires about two minutes to locate the cells on the dish and then about five seconds per cell to visit and irradiate each one. Technical details concerning each of the subsystems in the apparatus and representative biological data will be presented

  7. Operational characteristics of pediatric radiology: Image display stations

    Taira, R.K.

    1987-01-01

    The display of diagnostic images is accomplished in the UCLA Pediatric Radiology Clinical Radiology Imaging System (CRIS) using 3 different types of digital viewing stations. These include a low resolution station with six 512 x 512 monitors, a high resolution station with three 1024 x 1024 monitors, and a very high resolution workstation with two 2048 x 2048 monitors. The display stations provide very basic image processing manipulations including zoom and scroll, contrast enhancement, and contrast reversal. The display stations are driven by a computer system which is dedicated for clinical use. During times when the clinical computer is unavailable (maintenance or system malfunction), the 512 x 512 workstation can be switched to operate from a research PACS system in the UCLA Image Processing Laboratory via a broadband communication network. Our initial clinical implementation involves digital viewing for pediatric radiology conferences. Presentation of inpatient cases use the six monitor 512 x 512 multiple viewing station. Later stages of the clinical implementation involve the use of higher resolution displays for the purpose of primary diagnosis from video displays

  8. Operational characteristics of miniature loop heat pipe with flat evaporator

    Gai, Dongxing; Liu, Zhichun; Liu, Wei; Yang, Jinguo [Huazhong University of Science and Technology, School of Energy and Power Engineering, Wuhan, Hubei (China)

    2009-12-15

    Loop heat pipes are heat transfer devices whose operating principle is based on the evaporation and condensation of a working fluid, and which use the capillary pumping forces to ensure the fluid circulation. A series of tests have been carried out with a miniature loop heat pipe (mLHP) with flat evaporator and fin-and-tube type condenser. The loop is made of pure copper with stainless mesh wick and methanol as the working fluid. Detailed study is conducted on the start-up reliability of the mLHP at high as well as low heat loads. During the testing of mLHP under step power cycles, the thermal response presented by the loop to achieve steady state is very short. At low heat loads, temperature oscillations are observed throughout the loop. The amplitudes and frequencies of these fluctuations are large at evaporator wall and evaporator inlet. It is expected that the extent and nature of the oscillations occurrence is dependent on the thermal and hydrodynamic conditions inside the compensation chamber. The thermal resistance of the mLHP lies between 0.29 and 3.2 C/W. The effects of different liquid charging ratios and the tilt angles to the start-up and the temperature oscillation are studied in detail. (orig.)

  9. Vehicle operation characteristic under different ramp entrance conditions in underground road: Analysis, simulation and modelling

    Yao, Qiming; Liu, Shuo; Liu, Yang

    2018-05-01

    An experimental design was used to study the vehicle operation characteristics of different ramp entrance conditions in underground road. With driving simulator, the experimental scenarios include left or right ramp with first, second and third service level, respectively, to collect vehicle speed, acceleration, lateral displacement and location information at the ramp entrance section. By using paired t-test and ANOVA, the influence factors of vehicle operating characteristics are studied. The result shows that effects of ramp layout and mainline traffic environment on vehicle operation characteristics are significant. The regression model of vehicle traveling distance on acceleration lane is established. Suggestions are made for ramp entrance design of underground road.

  10. On the L-characteristic of nonlinear superposition operators in lp-spaces

    Dedagic, F.

    1995-04-01

    In this paper we describe the L-characteristic of the nonlinear superposition operator F(x) f(s,x(s)) between two Banach spaces of functions x from N to R. It was shown that L-characteristic of the nonlinear superposition operator which acts between two Lebesgue spaces has so-called Σ-convexity property. In this paper we show that L-characteristic of the operator F (between two Banach spaces) has the convexity property. It means that the classical interpolation theorem of Reisz-Thorin for a linear operator holds for the nonlinear operator superposition which acts between two Banach spaces of sequences. Moreover, we consider the growth function of the operator superposition in mentioned spaces and we show that one has the logarithmically convexity property. (author). 7 refs

  11. Logistic Regression Analysis of Operational Errors and Routine Operations Using Sector Characteristics

    Pfleiderer, Elaine M; Scroggins, Cheryl L; Manning, Carol A

    2009-01-01

    ...) and routine operation (RO) traffic samples. OE data were derived from SATORI re-creations of OEs occurring at the Indianapolis Air Route Traffic Control Center between 9/17/2001 and 12/10/2003...

  12. Personal, place, and time characteristics of offshore accidents in five oil companies operating in Indonesia

    Rahardjo; Sudjoko; Sebayang

    1991-01-01

    This study is to determine personal, place and time characteristics of offshore accidents during the year of 1987, 1988 and 1989 of five oil companies operating in Indonesia. Age, length of service, employment status, job characteristics, work cycles, work schedules, marital status, citizenship, disability, anatomy and nature of accident

  13. Operational characteristics of dual gain single cavity Nd:YVO 4 laser

    Operational characteristics of a dual gain single cavity Nd:YVO4 laser have been investigated. With semiconductor diode laser pump power of 2 W, 800 mW output was obtained with a slope efficiency of 49%. Further, by changing the relative orientation of the two crystals the polarization characteristics of the output could be ...

  14. Robust Biometric Score Fusion by Naive Likelihood Ratio via Receiver Operating Characteristics

    Tao, Q.; Veldhuis, Raymond N.J.

    This paper presents a novel method of fusing multiple biometrics on the matching score level. We estimate the likelihood ratios of the fused biometric scores, via individual receiver operating characteristics (ROC) which construct the Naive Bayes classifier. Using a limited number of operation

  15. Buyer-focused operations as a supply chain strategy : Identifying the influence of business characteristics

    van der Vaart, T; van Donk, DP

    2006-01-01

    Purpose - Buyer-focused operations aim at a high level of supply chain alignment by singling out resources for one buyer in order to serve this buyer optimally. The purpose of this paper is to identify what business characteristics make suppliers choose buyer-focused operations as a supply chain

  16. Operating characteristics of a three-stage Stirling pulse tube cryocooler operating around 5 K

    Qiu, L. M.; Cao, Q.; Zhi, X. Q.; Han, L.; Gan, Z. H.; Yu, Y. B.; Liu, Y.; Zhang, X. J.; Pfotenhauer, J. M.

    2012-07-01

    A Stirling pulse tube cryocooler (SPTC) operating at the liquid-helium temperatures represents an excellent prospect for satisfying the requirements of space applications because of its compactness, high efficiency and reliability. However, the working mechanism of a 4 K SPTC is more complicated than that of the Gifford McMahon (GM) PTC that operates at the relatively low frequency of 1-2 Hz, and has not yet been well understood. In this study, the primary operating parameters, including frequency, charge pressure, input power and precooling temperature, are systematically investigated in a home-developed separate three-stage SPTC. The investigation demonstrates that the frequency and precooling temperature are closely coupled via phase shift. In order to improve the cooling capacity it is important to lower the frequency and the precooling temperature simultaneously. In contrast to the behavior predicted by previous studies, the pressure dependence of the gas properties results in an optimized pressure that decreases significantly as the temperature is lowered. The third stage reaches a lowest temperature of 4.97 K at 29.9 Hz and 0.91 MPa. A cooling power of 25 mW is measured at 6.0 K. The precooling temperature is 23.7 K and the input power is 100 W.

  17. Study on the man-operator characteristics in the peak identification problem in line spectra

    Gopych, P.M.; Sorokin, V.I.; Sotnikov, V.V.

    1992-01-01

    ATOS program complex (automatical test spectra processing) realizing all stages of investigation necessary to obtain qualitative characteristics of the man-operator in the peak identification problem is developed. Qualitative characteristics of identitication ion quality of peaks by operators searching for peaks in line spectra are determined due to simulation experiment. It is shown, that for trained operators reference possibility of false detection of peaks is equal to F=0.012±0.004, while for untrained ones - F≅0.3. Comparison of results with analogous data on on-line programs for identification of peaks in γ-spectra is conducted

  18. Bootstrap-based procedures for inference in nonparametric receiver-operating characteristic curve regression analysis.

    Rodríguez-Álvarez, María Xosé; Roca-Pardiñas, Javier; Cadarso-Suárez, Carmen; Tahoces, Pablo G

    2018-03-01

    Prior to using a diagnostic test in a routine clinical setting, the rigorous evaluation of its diagnostic accuracy is essential. The receiver-operating characteristic curve is the measure of accuracy most widely used for continuous diagnostic tests. However, the possible impact of extra information about the patient (or even the environment) on diagnostic accuracy also needs to be assessed. In this paper, we focus on an estimator for the covariate-specific receiver-operating characteristic curve based on direct regression modelling and nonparametric smoothing techniques. This approach defines the class of generalised additive models for the receiver-operating characteristic curve. The main aim of the paper is to offer new inferential procedures for testing the effect of covariates on the conditional receiver-operating characteristic curve within the above-mentioned class. Specifically, two different bootstrap-based tests are suggested to check (a) the possible effect of continuous covariates on the receiver-operating characteristic curve and (b) the presence of factor-by-curve interaction terms. The validity of the proposed bootstrap-based procedures is supported by simulations. To facilitate the application of these new procedures in practice, an R-package, known as npROCRegression, is provided and briefly described. Finally, data derived from a computer-aided diagnostic system for the automatic detection of tumour masses in breast cancer is analysed.

  19. On the comparability of acceptance tests for concrete by operation characteristics

    Rackwitz, R.

    1978-01-01

    The purely statistical aspect of acceptance tests can be estimated by means of operation characteristics, the position and steepness of which determine the probability for acceptance or rejection of offered loads. For negative decisions in concrete checking there will be, as a rule, an after-check in normal quality control. The operation characteristics with after-check valid for DIN 1045, DIN 1084, and DIN 1048 are set up. Complete comparability of different acceptance tests by means of the operation characteristic can only be achieved if the different sampling rates and the number of decisions are also included in the consideration. Proposals for improving the acceptance tests for concrete are presented. (orig.) [de

  20. Altitude-Wind-Tunnel Investigation of a 4000-Pound-Thrust Axial-Flow Turbojet Engine. II - Operational Characteristics. II; Operational Characteristics

    Fleming, William A.

    1948-01-01

    An investigation was conducted in the Cleveland altitude wind tunnel to determine the operational characteristics of an axial flow-type turbojet engine with a 4000-pound-thrust rating over a range of pressure altitudes from 5,000 to 50,OOO feet, ram pressure ratios from 1.00 to 1.86, and temperatures from 60 deg to -50 deg F. The low-flow (standard) compressor with which the engine was originally equipped was replaced by a high-flow compressor for part of the investigation. The effects of altitude and airspeed on such operating characteristics as operating range, stability of combustion, acceleration, starting, operation of fuel-control systems, and bearing cooling were investigated. With the low-flow compressor, the engine could be operated at full speed without serious burner unbalance at altitudes up to 50,000 feet. Increasing the altitude and airspeed greatly reduced the operable speed range of the engine by raising the minimum operating speed of the engine. In several runs with the high-flow compressor the maximum engine speed was limited to less than 7600 rpm by combustion blow-out, high tail-pipe temperatures, and compressor stall. Acceleration of the engine was relatively slow and the time required for acceleration increased with altitude. At maximum engine speed a sudden reduction in jet-nozzle area resulted in an immediate increase in thrust. The engine started normally and easily below 20,000 feet with each configuration. The use of a high-voltage ignition system made possible starts at a pressure altitude of 40,000 feet; but on these starts the tail-pipe temperatures were very high, a great deal of fuel burned in and behind the tail-pipe, and acceleration was very slow. Operation of the engine was similar with both fuel regulators except that the modified fuel regulator restricted the fuel flow in such a manner that the acceleration above 6000 rpm was very slow. The bearings did not cool properly at high altitudes and high engine speeds with a low

  1. Evaluation of communication characteristics of operating teams in NPPs using SNA technique

    Kim, H. J.; Lee, S. W.; Kang, H. G.; Seong, P. H. [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Park, J. K. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kang, H. G. [Khalifa Univ. of Science, Abu Dhabi (United Arab Emirates)

    2012-03-15

    Inappropriate communications within operational teams can lead to serious consequences of a system since it can cause lack of exchange of important information to perform the task to secure the safety of the system in nuclear power plants (NPPs). For that reason, we studied the communication characteristics However, existing studies on the communication characteristics seem to have problem since they have characterized team communications from a single perspective. According that, we have developed an evaluation method to characterize team communications using social network techniques which can evaluate them from various perspectives which are group cohesiveness, frequency of communications, degree of hierarchy, and communication contents. In addition, we suggested some kids of specific communication characteristics of operating teams that can reduce the occurrence of inappropriate communications. Eight verbal protocol data which are audio-visual recorded under emergency training sessions by main control room (MCR) operating teams are used. As a result of the study, there was negative relationship between group cohesiveness and the ratio of inappropriate communications. Moreover, some kinds of specific communication contents are related to the ratio of inappropriate communications. Consequently, we can evaluate communications characteristics of operating teams in NPPs and suggest specific characteristics to provide useful insights to prevent inappropriate communications.

  2. Evaluation of communication characteristics of operating teams in NPPs using SNA technique

    Kim, H. J.; Lee, S. W.; Kang, H. G.; Seong, P. H.; Park, J. K.; Kang, H. G.

    2012-01-01

    Inappropriate communications within operational teams can lead to serious consequences of a system since it can cause lack of exchange of important information to perform the task to secure the safety of the system in nuclear power plants (NPPs). For that reason, we studied the communication characteristics However, existing studies on the communication characteristics seem to have problem since they have characterized team communications from a single perspective. According that, we have developed an evaluation method to characterize team communications using social network techniques which can evaluate them from various perspectives which are group cohesiveness, frequency of communications, degree of hierarchy, and communication contents. In addition, we suggested some kids of specific communication characteristics of operating teams that can reduce the occurrence of inappropriate communications. Eight verbal protocol data which are audio-visual recorded under emergency training sessions by main control room (MCR) operating teams are used. As a result of the study, there was negative relationship between group cohesiveness and the ratio of inappropriate communications. Moreover, some kinds of specific communication contents are related to the ratio of inappropriate communications. Consequently, we can evaluate communications characteristics of operating teams in NPPs and suggest specific characteristics to provide useful insights to prevent inappropriate communications

  3. Data Service:Characteristics,Market Structure,and the Role of Operator

    LI Ruo-peng; LU Ting-jie

    2005-01-01

    To study characteristics and market structure of data service and the role of operator,this paper makes a commercial model by applying the theory of intermediaries and neoclassic economics.Data service has different economic characteristics from voice service.Firstly,production mode of data service is roundabout production,secondly,driving power of data service is economies of specialization,and finally,management method of data service is impersonal management.In data service market,information asymmetry and barrier to entry determine transaction efficiency and the specialization level of service providers indirectly.Therefore,operator should intervene in the market by offering trade service in order to promote development of service providers.Because of different quality of service providers,market structure of data service must be the state that trade platform built by operator and intermediary platform built by operator coexists.

  4. Operating characteristics of a 2.0-MeV RFQ

    Purser, F.O.; Wadlinger, E.A.; Sander, O.R.; Potter, J.M.; Crandall, K.R.

    1983-01-01

    A second radio-frequency quadrupole (RFQ) accelerator has been designed, constructed and operated at Los Alamos National Laboratory. The accelerator's design parameters represent a major extension from the original Los Alamos RFQ, with the new accelerator being 2.5 times as long, having three times the output energy, and with 2.5 times the current limit. The new accelerator's operating characteristics were studied for 3 months before disassembly to incorporate design mofidications. Results are discussed

  5. Design features and operational characteristics of the PEP beam-transport and injection system

    Peterson, J.M.; Brown, K.L.; Truher, J.B.

    1981-03-01

    The PEP beam-transport system was designed to transmit 4-to-15 GeV electron and positron beams from the SLAC linac within a +- 0.8% momentum band, to have flexible tuning of the betatron and off-momentum functions for matching into the PEP storage ring, and to have convenient operating characteristics. The transport lines were brought into operation quickly and have operated well. Electron injection has been consistent and efficient and relatively easy to accomplish. Positron injection also has been satisfactory but is variable and more sensitive to ring conditions

  6. Preliminary analysis of the operating characteristics of a generic repository receiving facility: Status report

    1985-10-01

    The operating characteristics of a repository receiving facility structured around current technology and practices have been reviewed. Cask turnaround times and operator doses were estimated. Large throughout and long-term receiving operations at a nuclear waste repository result in an unprecedented number of casks being handled. While the current generation of material-handling equipment is adequate to process the casks, personnel radiation exposures for the generic facility analyzed are unacceptably high. This emphasizes the need for development of occupational radiation exposure control concepts for application in repository receiving facilities. 3 refs., 22 figs., 6 tabs

  7. Employing the therapeutic operating characteristic (TOC) graph for individualised dose prescription

    Hoffmann, A.L.; Huizenga, H.; Kaanders, J.H.A.M.

    2013-01-01

    BACKGROUND: In current practice, patients scheduled for radiotherapy are treated according to 'rigid' protocols with predefined dose prescriptions that do not consider risk-taking preferences of individuals. The therapeutic operating characteristic (TOC) graph is applied as a decision-aid to assess

  8. Ion counting method and it's operational characteristics in gas chromatography-mass spectrometry

    Fujii, Toshihiro

    1976-01-01

    Ion counting method with continuous channel electron multiplier which affords the direct detection of very small ion currents and it's operational characteristics were studied in gas chromatography-mass spectrometry. Then this method was applied to the single ion detection technique of GC-MS. A detection limit was measured, using various standard samples of low level concentration. (auth.)

  9. PFP vault operations containers for Plutonium Handling and Storage Critical Characteristics

    BONADIE, E.P.

    2000-01-01

    This document specifies the critical characteristics for containers procured for Plutonium Finishing Plant's (PFP's) Vault Operations system as required by HNF-PRO-268 and HNF-PRO-1819. These are the minimum specifications that the equipment must meet in order to perform its safety function

  10. Receiver operating characteristics of perceptrons : Influence of sample size and prevalence

    Freking, Ansgar; Biehl, Michael; Braun, Christian; Kinzel, Wolfgang; Meesmann, Malte

    1999-01-01

    In many practical classification problems it is important to distinguish false positive from false negative results when evaluating the performance of the classifier. This is of particular importance for medical diagnostic tests. In this context, receiver operating characteristic (ROC) curves have

  11. Calculation characteristics of centrifugal compressor operates on a mixture of gases

    Novitskiy, B. B.; Arbekov, A. N.

    2016-10-01

    The creation of Closed Brayton Cycle (CBC) unit is impossible without developing the basic knots. This work is devoted to determining the characteristics of a centrifugal compressor when operating at various working bodies with the help of experimental and numerical studies.

  12. Study on the construction and its operating characteristics of Marx high voltage pulse generator

    Chung, W.K.; Yook, C.C.

    1984-01-01

    This study is to investigate the operating characteristics of a Marx high voltage pulse generator, which is designed and fabricated for the purpose of constructing a linear theta-pinch plasma generating facility. The Marx generator consists of a 2 kJ capacitor bank of maximum output voltage of 200kV, a set of main spark switch, a triggring system, and high voltage charging power supply. The experimental results show that the operating characteristics of the generator can be controlled through varying nitrogen pressure as a filling gas. The output pulse of the generator is achieved close to the estimated voltage with the rise time of 3*m seconds. The stability of the generator is also very satisfactory within operating range of main spark switch. (Author)

  13. A study on operators' cognitive response characteristics to the computerized working environment

    Lee, Yong Hee; Lee, Jang Soo; Suh, Sang Moon; Lee, Hyun Cheol; Jung, Kwang Tae; Lee, Dhong Ha

    1998-12-01

    Although the introduction of computerized working environment to the nuclear facilities, the study on the human factors impacts of computers and automation has not been enough like the other industries. It is necessary to prepare the way to cope with the negative aspects in spite of many positive aspects of computerization in nuclear. This study is an empirical study including the survey of the human factor concerning, especially to the cognitive response of operators' and the experiments on the error proneness. At first, we survey the design and its changes of operator interface and interaction in nuclear power plants, and conclude five human factor issues. We discuss situation awareness issues as one of the major human factor concerning, and the assessment method. Secondly, a questionnaire and interviews survey to the operator's response characteristics are performed for possible criterion measures tot he in-depth study on the cognitive characteristics. Finally, several experiments are conducted to test the error proneness. The issues and findings of this study could be utilized to any further study on the cognitive characteristic of operators to the computerized work environment

  14. A study on operators' cognitive response characteristics to the computerized working environment

    Lee, Yong Hee; Lee, Jang Soo; Suh, Sang Moon; Lee, Hyun Cheol; Jung, Kwang Tae; Lee, Dhong Ha

    1998-12-01

    Although the introduction of computerized working environment to the nuclear facilities, the study on the human factors impacts of computers and automation has not been enough like the other industries. It is necessary to prepare the way to cope with the negative aspects in spite of many positive aspects of computerization in nuclear. This study is an empirical study including the survey of the human factor concerning, especially to the cognitive response of operators' and the experiments on the error proneness. At first, we survey the design and its changes of operator interface and interaction in nuclear power plants, and conclude five human factor issues. We discuss situation awareness issues as one of the major human factor concerning, and the assessment method. Secondly, a questionnaire and interviews survey to the operator's response characteristics are performed for possible criterion measures to the in-depth study on the cognitive characteristics. Finally, several experiments are conducted to test the error proneness. The issues and findings of this study could be utilized to any further study on the cognitive characteristic of operators to the computerized work environment.

  15. Study of geometrical and operational parameters controlling the low frequency microjet atmospheric pressure plasma characteristics

    Kim, Dan Bee; Rhee, J. K.; Moon, S. Y.; Choe, W.

    2006-01-01

    Controllability of small size atmospheric pressure plasma generated at low frequency in a pin to dielectric plane electrode configuration was studied. It was shown that the plasma characteristics could be controlled by geometrical and operational parameters of the experiment. Under most circumstances, continuous glow discharges were observed, but both the corona and/or the dielectric barrier discharge characteristics were observed depending on the position of the pin electrode. The plasma size and the rotational temperature were also varied by the parameters. The rotational temperature was between 300 and 490 K, being low enough to treat thermally sensitive materials

  16. Part 5: Receiver Operating Characteristic Curve and Area under the Curve

    Saeed Safari

    2016-04-01

    Full Text Available Multiple diagnostic tools are used by emergency physicians,every day. In addition, new tools are evaluated to obtainmore accurate methods and reduce time or cost of conventionalones. In the previous parts of this educationalseries, we described diagnostic performance characteristicsof diagnostic tests including sensitivity, specificity, positiveand negative predictive values, and likelihood ratios. Thereceiver operating characteristics (ROC curve is a graphicalpresentation of screening characteristics. ROC curve is usedto determine the best cutoff point and compare two or moretests or observers by measuring the area under the curve(AUC. In this part of our educational series, we explain ROCcurve and two methods to determine the best cutoff value.

  17. Characteristics of switched reluctance motor operating in continuous and discontinuous conduction mode

    Ćalasan Martin P.

    2013-01-01

    Full Text Available This paper presents mechanical characteristics of Switched Reluctance Motor (SRM when it operates in Discontinuous Conduction Mode (DCM or in Continuous Conduction Mode (CCM, i.e. when the current through the phase coils (windings flows discontinuously or continuously. Firstly, in order to maximize the output power of SRM optimization of its control parameters was performed, such that the peak and RMS values of the current do not exceed the predefined values. The optimal control parameters vs. rotation speed, as well as the corresponding characteristics of torque, power and efficiency. It is shown that with CCM the machine torque (power, at high speed, can be increased.

  18. Studying the dynamical characteristics of pumps in NPP unit auxiliary water system under operational conditions

    Belyaev, S.G.; Puzanov, A.I.; Belikov, V.P.; Dizik, B.S.

    1990-01-01

    Hydrodynamic loads appearing in the flow-through part of pump aggregates of the system of auxiliary water supply in NPP with variations in the operation modes are investigated. It is shown that during operation of centrifugal pumps the position of the mode on the pump characteristic plot must be controlled. When the mode point exceeds the limits of the working zone it results in a considerable increase of dynamic loads: pressure pulsation and vibration. As the flow rate increase the decrease in dynamic loads is recorded at low frequencies of about 2-4 Hz

  19. Further characteristics important in the operation of ceramic BeO TLD

    Gammage, R.B.

    1977-01-01

    There is now a considerable volume of published research dealing with ceramic BeO--TLD (Crase and Gammage, 1975; Yamashita et al., 1974; Scarpa et al., 1971). Its high sensitivity to radiation (1 mR), cheapness, commercial availability, non-toxicity, chemical stability, an atomic number of near tissue equivalence, and resistance to thermal fading, suggest that it should, by now, have found widespread acceptance as a TLD phosphor. It has not. There are only a small handful of reports dealing with the practical application of this type of dosimeter (Puite et al., 1974; Gammage and Haywood, 1976; Gesell et al., 1975). It seems wise, therefore, to look at the phosphor more closely and to focus on characteristics likely to cause problems under real operating conditions, especially those which are acting as a deterrent to its widespread acceptance. Operational characteristics were studied and the results are discussed

  20. Perfectionism, selected demographic and job characteristics as predictors of burnout in operating suite nurses

    Dorota Włodarczyk

    2013-12-01

    Full Text Available Background: The study was aimed at verifying the predictive power of perfectionism for professional burnout among nurses exposed to distress resulting from work in an operating suite and testing whether this effect exists after controlling for selected demographic and job characteristics. Material and Methods: The study group consisted of 100 nurses (93 women; mean age: 38.67 years. The majority in the group worked in public facilities (68%, in duty system (62%, as operating (75% or anesthesiology (25% nurses. To test perfectionism The Polish Adaptive and Maladaptive Perfectionism Questionnaire (AMPQ (Perfekcjonizm Adaptacyjny i Dezadaptacyjny - PAD, developed by Szczucka, was used. To examine burnout the Oldenburg Burnout Inventory (OLBI by Demerouti et al. was adopted. The effects of selected demographic and job characteristics were controlled. Results: The results of hierarchical regression analyses revealed that after controlling for selected demographic and job characteristics maladaptive perfectionism was a significant predictor of disengagement and exhaustion whereas adaptive perfectionism predicted a better work engagement. Significant predictors were also: education, number of workplaces, duty system and marital status. Conclusions: The study allowed to confirm the hypothesis on a harmful role of maladaptive perfectionism in shaping burnout among operating suite nurses. The hypothesis on protective function of adaptive perfectionism was confirmed only partially, with regard to disengagement. The results of the study also highlighted some risk factors of burnout which may exist in this occupational group. This confirms the need to continue research in this area. Med Pr 2013;64(6:761–773

  1. Planning for success: desired characteristics of special operations surgeons, a pilot study.

    Campbell, Barrett H; Alderman, Shawn M

    2012-01-01

    Selection criteria for Special Operations Forces (SOF) physicians are often unclear to potential candidates without prior SOF experience. To date, no published career resource exists to guide the careers of physicians interested in becoming a SOF surgeon. Using a survey tool, desirable characteristics and personal attributes were identified that can be used to inform candidate career decisions and better prepare them for a future position in Special Operations. A descriptive, cross-sectional survey instrument was developed and distributed to current Army SOF Command Surgeons for further distribution to subordinate surgeons. RESULTS were analyzed as a cohort and by subordinate command. Respondents consisted of current SOF Surgeons. Uniformly, the individual characteristics most strongly desired are professionalism, being a team player, and leadership. Possessing or obtaining Airborne and Flight Surgeon qualifications prior to consideration for a surgeon position was highly desired. Residency training within Family Medicine or Emergency Medicine constituted the vast majority of specialty preference. Understanding which characteristics and attributes are desirable to current surgeons and commanders can aid physicians interested in SOF surgeon positions. Using this study and future studies can guide career planning and foster the selection of ideally trained physicians who will operate at the tip of the spear. The views expressed are those of the author(s) and do not reflect the official policy of the Department of the Army, the Department of Defense or the U.S. Government. 2012.

  2. Characteristics of the prices of operating reserves and regulation services in competitive electricity markets

    Wang Peng; Zareipour, Hamidreza; Rosehart, William D.

    2011-01-01

    In this paper, characteristics of the prices of reserves and regulation services in the Ontario, New York and ERCOT electricity markets are studied. More specifically, price variability, price jumps, long-range correlation, and non-linearity of the prices are analyzed using the available measures in the literature. For the Ontario electricity market, the prices of 10-min spinning, 10-min non-spinning, and 30-min operating reserves for the period May 1, 2002 to December 31, 2007 are analyzed. For the New York market, prices of the same reserves plus regulation service are studied for the period February 5, 2005 to December 31, 2008. For the ERCOT market, we analyze the prices of responsive reserve, regulation up and regulation down services, for the period January 1, 2005 to December 31, 2009. The studied characteristics of operating reserve and regulation prices are also compared with those of energy prices. The findings of this paper show that the studied reserve and regulation prices feature extreme volatility, more frequent jumps and spikes, different peak price occurrence time, and lower predictability, compared to the energy prices. - Research highlights: → We examine various statistical characteristics of reserve and regulation prices. → We compare characteristics of reserve and regulation and energy prices. → Reserve and regulation prices feature different patterns from energy prices. → Reserve and regulation prices are more dispersive and volatile than energy price.

  3. Investigation of the I-40 Jet-Propulsion Engine in the Cleveland Altitude Wind Tunnel. V - Operational Characteristics. 5; Operational Characteristics

    Golladay, Richard L.; Gendler, Stanley L.

    1947-01-01

    An investigation has been conducted in the Cleveland altitude wind tunnel to determine the operational characteristics of the I-40 jet-propulsion engine over a range of pressure altitudes from 10,000 to 50,000 feet and ram-pressure ratios from 1.00 to 1.76. Engine operational data were obtained with the engine in the standard configuration and with various modifications of the fuel system, the electrical system, and the combustion chambers. The effects of altitude and airspeed on operating speed range, starting, windmilli.ng, acceleration, speed regulation, cooling, and vibration of the standard and modified engines were determined, and damage to parts was noted. Maximum engine speed was obtainable at all altitudes and airspeeds wi th each fuel-control system investigated. The minimum idling speed was raised by increases in altitude and airspeed. The lowest minimum stable speeds were obtained with the standard configuration using 40-gallon nozzles with individual metering plugs. The engine was started normally at altitudes as high as 20,000 feet with all of the fuel systems and ignition combinations except one. Ignition at 70,000 feet was difficult and, although successful ignition occurred, acceleration was slow and usually characterized by excessive tail-pipe temperature. During windmilling investigations of the engine equipped with the standard fuel system, the engine could not be started at ram-pressure ratios of 1.1 to 1.7 at altitudes of 10,000, 20,000 and 30,000 feet. When equipped with the production barometric and Monarch 40-gallon nozzles, the engine accelerated in 12 seconds from an engine speed of 6000 rpm to 11,000 rpm at 20,000 feet and an average tail-pipe temperature of 11000 F. At the same altitude and temperature, all the engine configurations had approximately the same rate of acceleration. The Woodward governor produced the safest accelerations, inasmuch as it could be adjusted to automatically prevent acceleration blow out. The engine speed was

  4. NORMALIZATION OF AUTOMOTIVE BRAKE CHARACTERISTICS WHILE OPERATING THEM IN THE REPUBLIC OF BELARUS

    I. M. Flerko

    2012-01-01

    Full Text Available Safety provision for the operated auto-transport facilities is of great significance all over the world. The problem is also considered as an actual one for the automotive transport of theRepublicofBelarus. Provision of higher brake system reliability for the operated vehicles is one of the directions to solve the problem pertaining to improve traffic safety.The paper contains an analysis of basic national standard documents which regulate brake characteristics for the operated vehicles, evaluates checking methods of braking efficiency and vehicle stability at the moment of braking, considers some problems pertaining to methods used for checking and estimation of braking control systems of transport facilities. 

  5. An investigation of the acoustic characteristics of a compression ignition engine operating with biodiesel blends

    Zhen, D.; Tesfa, B.; Yuan, X.; Wang, R.; Gu, F.; Ball, A. D.

    2012-05-01

    In this paper, an experimental investigation has been carried out on the acoustic characteristics of a compression ignition (CI) engine running with biodiesel blends under steady state operating conditions. The experiment was conducted on a four-cylinder, four-stroke, direct injection and turbocharged diesel engine which runs with biodiesel (B50 and B100) and pure diesel. The signals of acoustic, vibration and in-cylinder pressure were measured during the experiment. To correlate the combustion process and the acoustic characteristics, both phenomena have been investigated. The acoustic analysis resulted in the sound level being increased with increasing of engine loads and speeds as well as the sound characteristics being closely correlated to the combustion process. However, acoustic signals are highly sensitive to the ambient conditions and intrusive background noise. Therefore, the spectral subtraction was employed to minimize the effects of background noise in order to enhance the signal to noise ratio. In addition, the acoustic characteristics of CI engine running with different fuels (biodiesel blends and diesel) was analysed for comparison. The results show that the sound energy level of acoustic signals is slightly higher when the engine fuelled by biodiesel and its blends than that of fuelled by normal diesel. Hence, the acoustic characteristics of the CI engine will have useful information for engine condition monitoring and fuel content estimation.

  6. Study of the dynamic operational characteristics of the Taiwan Power Company system - a nuclear majority system

    Yu, I.H.

    1982-01-01

    All conclusions drawn in this dissertation are based on the results of about six hundred study cases. The dynamic characteristics of the present Taiwan Power Company system are very different not only from the characteristics of any other power system in the world but also from Taipower's own history characteristics. Based on the engineers' knowledge, this dissertation takes a calculation risk approach to deal with the problems in the energy systems. Chapter I introduces the information related with the stability of the present Taipower system. Taipower operating engineers are facing the problem of committing a large amount of nuclear generation at a low base load level. The general introduction of the stability program developed for this study is described in Chapter II. In Chapter III, the processes of performing the transient stability study are explained to show how this study was performed. Critical tie flows were suggested in Chapter IV, which might help balance the nuclear generation and thermal generation at the base load level and plan the unit maintenance schedule. Several operation modes which may increase the degree of stability or minimize the number unit trippings were discussed in Chapter V. In Chapter VI, how to adjust the load shedding policy to improve the stability are discussed. The remote tripping scheme which is effective in preventing massive system blackout was studied in Chapter VII. Some broader concepts in load management are presented in Chapter VII for Taipower's management decision

  7. Operational Characteristics Identification and Simulation Model Verification for Incheon International Airport

    Eun, Yeonju; Jeon, Daekeun; Lee, Hanbong; Zhu, Zhifan; Jung, Yoon C.; Jeong, Myeongsook; Kim, Hyounkyong; Oh, Eunmi; Hong, Sungkwon; Lee, Junwon

    2016-01-01

    integrated into NASA's Airspace Technology Demonstration-2 (ATD-2) project for technology demonstration of Integrated Arrival-Departure-Surface (IADS) operations at CLT. This study is a part of the international research collaboration between KAIA (Korea Agency for Infrastructure Technology Advancement), KARI (Korea Aerospace Research Institute) and NASA, which is being conducted to validate the effectiveness of SARDA concept as a controller decision support tool for departure and surface management of ICN. This paper presents the preliminary results of the collaboration effort. It includes investigation of the operational environment of ICN, data analysis for identification of the operational characteristics of the airport, construction and verification of airport simulation model using Surface Operations Simulator and Scheduler (SOSS), NASA's fast-time simulation tool.

  8. Heat transfer characteristics and operation limit of pressurized hybrid heat pipe for small modular reactors

    Kim, Kyung Mo; Bang, In Cheol

    2017-01-01

    Highlights: • Thermal performances and operation limits of hybrid heat pipe were experimentally studied. • Models for predicting the operation limit of the hybrid heat pipe was developed. • Non-condensable gas affected heat transfer characteristics of the hybrid heat pipe. - Abstract: In this paper, a hybrid heat pipe is proposed for use in advanced nuclear power plants as a passive heat transfer device. The hybrid heat pipe combines the functions of a heat pipe and a control rod to simultaneously remove the decay heat generated from the core and shutdown the reactor under accident conditions. Thus, the hybrid heat pipe contains a neutron absorber in the evaporator section, which corresponds to the core of the reactor pressure vessel. The presence of the neutron absorber material leads to differences in the heated diameter and hydraulic diameter of the heat pipe. The cross-sectional areas of the vapor paths through the evaporator, adiabatic, and condenser sections are also different. The hybrid heat pipe must operate in a high-temperature, high-pressure environment to remove the decay heat. In other words, the operating pressure must be higher than those of the commercially available thermosyphons. Hence, the thermal performances, including operation limit of the hybrid heat pipe, were experimentally studied in the operating pressure range of 0.2–20 bar. The operating pressure of the hybrid heat pipe was controlled by charging the non-condensable gas which is unused method to achieve the high saturation pressure in conventional thermosyphons. The effect of operating pressure on evaporation heat transfer was negligible, while condensation heat transfer was affected by the amount of non-condensable gas in the test section. The operation limit of the hybrid heat pipe increased with the operating pressure. Maximum heat removal capacity of the hybrid heat pipe was up to 6 kW which is meaningful value as a passive decay heat removal device in the nuclear power

  9. Transmission Technologies and Operational Characteristic Analysis of Hybrid UHV AC/DC Power Grids in China

    Tian, Zhang; Yanfeng, Gong

    2017-05-01

    In order to solve the contradiction between demand and distribution range of primary energy resource, Ultra High Voltage (UHV) power grids should be developed rapidly to meet development of energy bases and accessing of large-scale renewable energy. This paper reviewed the latest research processes of AC/DC transmission technologies, summarized the characteristics of AC/DC power grids, concluded that China’s power grids certainly enter a new period of large -scale hybrid UHV AC/DC power grids and characteristics of “strong DC and weak AC” becomes increasingly pro minent; possible problems in operation of AC/DC power grids was discussed, and interaction or effect between AC/DC power grids was made an intensive study of; according to above problems in operation of power grids, preliminary scheme is summarized as fo llows: strengthening backbone structures, enhancing AC/DC transmission technologies, promoting protection measures of clean energ y accessing grids, and taking actions to solve stability problems of voltage and frequency etc. It’s valuable for making hybrid UHV AC/DC power grids adapt to operating mode of large power grids, thus guaranteeing security and stability of power system.

  10. Performance and emission characteristics of biogas used in diesel engine operation

    Makareviciene, Violeta; Sendzikiene, Egle; Pukalskas, Saugirdas; Rimkus, Alfredas; Vegneris, Ricardas

    2013-01-01

    Highlights: • Biogas is an environmentally friendly biofuel for diesel engines. • Results of diesel engine tests when fuelling with biogas are presented. • Engine and environmental characteristics depends on carbon dioxide content in biogas. • Using biogas in a diesel engine requires certain operational modifications. - Abstract: The objective of this study it to evaluate the impact of the carbon dioxide concentration in biogas on the operating characteristics and exhaust gas emissions of a diesel engine running on a mixture of biogas and mineral diesel fuel. The tests were carried out in two stages. In the first stage, the impact of different biogas compositions and the exhaust gas recirculation system (EGR) on the engine parameters was determined. Lower pollutant levels were measured in the studies without the EGR system, except for the nitrogen oxides NO x levels. The NO x concentration decrease was directly proportional to the concentration of methane in the common fuel mixture. In the second stage, the gas with the highest methane content was used to determine the impact of the start of injection timing on the engine operating parameters. As the methane content in the common fuel mixture increased, the start of injection timing had to be progressively advanced to increase the thermal efficiency and to lower the fuel consumption, the CO and HC concentrations and the smokiness of the exhaust; however, advancing the start of injection timing increased NO x pollution

  11. DIADEME: A computer code to assess in operation defective fuel characteristics and primary circuit contamination

    Genin, J.B. [DEN/DEC/S3C, CEA Cadarache, 13 - Saint-Paul-lez-Durance (France); Harrer, A. [EdF/SEPTEN, 69 - Villeurbanne (France); Musante, Y. [FRAMATOME-ANP, 69 - Lyon (France)

    2002-07-01

    DIADEME is a computer code developed within the framework of R and D cooperation between the French Atomic Energy Commission (CEA), Electricite de France (EdF) and FRAMATOME-ANP. Its aim is to assess in operation defective fuel characteristics and primary circuit contamination for actinides and long half-life fission products involved in health physics problems as well as in waste and decommissioning studies. DIADEME has been developed and qualified for the EDF nuclear power plants. For many years, both theoretical and experimental studies have been carried out at the CEA on the release of fission products and actinides out of defective fuel rods in operation, their migration and deposition in PWR primary circuits. These studies have allowed defect characteristic diagnosis methods to be developed, based on radiochemical measurements of the primary coolant. These methods are generally used along with gamma spectrometry measurements on primary water sampling. In order to be completely efficient, these methods can also be used in connection with an on-line primary water gamma spectrometry device. This permits to obtain the most comprehensive data on fission product activity evolutions at steady state and during operation transients, and allows the on-line characterization of the defective fuel assemblies. For long half-life fission products and for actinides, DIADEME is also able to assess the activities of soluble and insoluble forms in the primary water and in the chemical and voluminal control system (CVCS) filters and resins, as well as those activities deposited on primary circuit surfaces. (author)

  12. DIADEME: A computer code to assess in operation defective fuel characteristics and primary circuit contamination

    Genin, J.B.; Harrer, A.; Musante, Y.

    2002-01-01

    DIADEME is a computer code developed within the framework of R and D cooperation between the French Atomic Energy Commission (CEA), Electricite de France (EdF) and FRAMATOME-ANP. Its aim is to assess in operation defective fuel characteristics and primary circuit contamination for actinides and long half-life fission products involved in health physics problems as well as in waste and decommissioning studies. DIADEME has been developed and qualified for the EDF nuclear power plants. For many years, both theoretical and experimental studies have been carried out at the CEA on the release of fission products and actinides out of defective fuel rods in operation, their migration and deposition in PWR primary circuits. These studies have allowed defect characteristic diagnosis methods to be developed, based on radiochemical measurements of the primary coolant. These methods are generally used along with gamma spectrometry measurements on primary water sampling. In order to be completely efficient, these methods can also be used in connection with an on-line primary water gamma spectrometry device. This permits to obtain the most comprehensive data on fission product activity evolutions at steady state and during operation transients, and allows the on-line characterization of the defective fuel assemblies. For long half-life fission products and for actinides, DIADEME is also able to assess the activities of soluble and insoluble forms in the primary water and in the chemical and voluminal control system (CVCS) filters and resins, as well as those activities deposited on primary circuit surfaces. (author)

  13. The Fibromyalgia Impact Questionnaire (FIQ): a review of its development, current version, operating characteristics and uses.

    Bennett, R

    2005-01-01

    The Fibromyalgia Impact Questionnaire (FIQ) was developed in the late 1980s by clinicians at Oregon Health & Science University in an attempt to capture the total spectrum of problems related to fibromyalgia and the responses to therapy. It was first published in 1991 and since that time has been extensively used as an index of therapeutic efficacy. Overall, it has been shown to have a credible construct validity, reliable test-retest characteristics and a good sensitivity in demonstrating therapeutic change. The original questionnaire was modified in 1997 and 2002, to reflect ongoing experience with the instrument and to clarify the scoring system. The latest version of the FIQ can be found at the web site of the Oregon Fibromyalgia Foundation (www.myalgia.com/FIQ/FIQ). The FIQ has now been translated into eight languages, and the translated versions have shown operating characteristics similar to the English version.

  14. Assessing operating characteristics of CAD algorithms in the absence of a gold standard

    Roy Choudhury, Kingshuk; Paik, David S.; Yi, Chin A.; Napel, Sandy; Roos, Justus; Rubin, Geoffrey D.

    2010-01-01

    Purpose: The authors examine potential bias when using a reference reader panel as ''gold standard'' for estimating operating characteristics of CAD algorithms for detecting lesions. As an alternative, the authors propose latent class analysis (LCA), which does not require an external gold standard to evaluate diagnostic accuracy. Methods: A binomial model for multiple reader detections using different diagnostic protocols was constructed, assuming conditional independence of readings given true lesion status. Operating characteristics of all protocols were estimated by maximum likelihood LCA. Reader panel and LCA based estimates were compared using data simulated from the binomial model for a range of operating characteristics. LCA was applied to 36 thin section thoracic computed tomography data sets from the Lung Image Database Consortium (LIDC): Free search markings of four radiologists were compared to markings from four different CAD assisted radiologists. For real data, bootstrap-based resampling methods, which accommodate dependence in reader detections, are proposed to test of hypotheses of differences between detection protocols. Results: In simulation studies, reader panel based sensitivity estimates had an average relative bias (ARB) of -23% to -27%, significantly higher (p-value <0.0001) than LCA (ARB -2% to -6%). Specificity was well estimated by both reader panel (ARB -0.6% to -0.5%) and LCA (ARB 1.4%-0.5%). Among 1145 lesion candidates LIDC considered, LCA estimated sensitivity of reference readers (55%) was significantly lower (p-value 0.006) than CAD assisted readers' (68%). Average false positives per patient for reference readers (0.95) was not significantly lower (p-value 0.28) than CAD assisted readers' (1.27). Conclusions: Whereas a gold standard based on a consensus of readers may substantially bias sensitivity estimates, LCA may be a significantly more accurate and consistent means for evaluating diagnostic accuracy.

  15. Operational characteristics of the OMEGA short-wavelength laser fusion facility

    Soures, J.M.; Hutchison, R.; Jacobs, S.; McCrory, R.L.; Peck, R.; Seka, W.

    1984-01-01

    Twelve beams of the OMEGA, 24 beam direct-drive laser facility have been converted to 351-nm wavelength operation. The performance characteristics of this short-wavelength facility will be discussed. Beam-to-beam energy balance of +-2.3% and on-target energy, at 351-nm, in excess of 70 J per beam have been demonstrated. Long-term performance (>600 shots) of the system has been optimized by appropriate choice of index matching liquid, optical materials and coatings. The application of this system in direct-drive laser fusion experiments will be discussed

  16. Receiver operating characteristic analysis of chest radiographs with computed radiography and conventional analog films

    Morioka, C.; Brown, K.; Dalter, S.; Milos, M.J.; Huang, H.K.; Kangarloo, H.; Boechat, I.M.; Batra, P.

    1988-01-01

    Receiver operating characteristic is used to compare the image quality of films obtained digitally using computed radiography (CR) and conventionally using analog film following fluoroscopic examination. Twenty-four cases, some with a solitary noncalcified nodule and/or pneumothorax, were collected. Ten radiologists have been tested viewing analog and CR digital films separately. Preliminary results indicate that there is no significant difference in the ability to detect either a pneumothorax or a solitary noncalcified nodule when comparing CR digital film with conventional analog film. A comparison of the CR digital image displayed on a 2,048-line monitor against analog and CR digital film is in progress

  17. Borehole heat exchangers: Longterm operational characteristics of a decentral geothermal heating system

    Rybach, L.; Eugster, W.J.; Hopkirk, R.J.; Kaelin, B.

    1992-01-01

    The heat pump-coupled borehole heat exchanger (BHE) is an efficient and small geothermal energy system for supplying heat typically to a single dwelling house. The long-term performance characteristics have been investigated by computer simulations. The numerical models were validated by measurements at instrumented BHE facilities. The results show the development of a new thermal equilibrium state after the first few years of BHE operation. The thermal influence is limited to the first few meters of the ground surrounding the BHE. The BHE could be scaled up in order to be installed in deep 'failed' holes (e.g. dry geothermal or hydrocarbon exploration holes)

  18. The specification and the operation characteristics of the low energy accelerator in JAERI-TRCRE

    Haruyama, Yasuyuki; Yotsumoto, Keiichi; Okamoto, Jiro

    1993-06-01

    The low energy accelerator system of JAERI TRCRE is of a non scanned type electron accelerator, manufactured by NISSIN HIGH VOLTAGE Co., LTD. The system consists of an oil filled d.c.high voltage generator, semicylindrical acceleration chamber in which a linear cathode is supported coaxially, and the products handling conveyor. The high voltage generator and the acceleration chamber are connected by a flexible cable. A batch irradiation can be carried out using the conveyor in inert gases. The output of the accelerator is 300 kV, 100 mA and the beam width is 60 cm. The specification, the operation procedure, and the operation characteristics of the system are described. (author)

  19. Analysis on operation characteristics and power burdens of the double quench trigger type SFCLs

    Lim, Seung Taek; Lim, Sung Hun [Dept. of Electrical Engineering, Soongsil University, Seoul (Korea, Republic of); Han, Tae Hee [Dept. of Aero Materials Engineering, Jungwon University, Goesan (Korea, Republic of)

    2017-06-15

    To protect the power systems from fault current, the rated protective equipment should be installed. However growth of power system scale and concentration of loads caused the large fault current in power transmission system and distribution system. The capacities of installed protective equipment have been exceeded the due to increase of fault current. This increase is not temporary phenomenon but will be steadily as long as the industry develops. The power system operator need a counter-measurement for safety, so superconducting fault current limiter (SFCL) has been received attention as effective solutions to reduce the fault current. For the above reasons various type SFCLs have been studied recently. In this paper, operation characteristics and power burden of trigger type SFCL is studied. The trigger type SFCL has been used for real system research in many countries. Another trigger type SFCL (double quench trigger type SFCL) is also studied. For this paper, short circuit test is performed.

  20. Computer Drawing Method for Operating Characteristic Curve of PV Power Plant Array Unit

    Tan, Jianbin

    2018-02-01

    According to the engineering design of large-scale grid-connected photovoltaic power stations and the research and development of many simulation and analysis systems, it is necessary to draw a good computer graphics of the operating characteristic curves of photovoltaic array elements and to propose a good segmentation non-linear interpolation algorithm. In the calculation method, Component performance parameters as the main design basis, the computer can get 5 PV module performances. At the same time, combined with the PV array series and parallel connection, the computer drawing of the performance curve of the PV array unit can be realized. At the same time, the specific data onto the module of PV development software can be calculated, and the good operation of PV array unit can be improved on practical application.

  1. Analysis on Biomechanical Characteristics of Post-operational Vertebral C5-C6 Segments

    Heqiang Tian

    2016-03-01

    Full Text Available Both anterior cervical decompression and fusion (ACDF and artificial cervical disc replacement (ACDR have obvious advantages in the treatment of cervical spondylosis. To analyze the operation results, it is absolutely necessary to study the biomechanics of the movement range of post-operational vertebral C5-C6 segments, especially the biomechanical characteristics in cervical tissues in actual movements. In this study, using the human vertebral 3D graph gained by imaging diagnosis (CT, a vertebral solid model is established by the 3D reconstruction algorithm and reverse engineering technology. After that, with cervical soft tissue structure added to the solid model and set with a joint contact mechanism, a finite element model with a complete, accurate cervical C5-C6 kinematic unit is constructed, based on relevant physiological anatomical knowledge. This model includes vertebral segments, an intervertebral disc, ligament and zygopophysis in the cervical C5-C6 kinematic unit. In the created vertebral finite element model, the model is amended, referring to ACDF and ACDR, and the load and constraint are applied to a normal group, a fusion group and a displacement group, so as to analyze the biomechanical characteristics of the cervical vertebra after ACDF and ACDR. By comparing the finite element simulation results of different surgeries, this paper is intended to evaluate the functions and biomechanical behaviors of the post-operational vertebra, and explore the influence of the operation on the biomechanical stability of the cervical vertebra. This will provide theoretical guidance for implementation and optimization of ACDF and ACDR.

  2. Operational features and air plasma characteristics of a thermal plasma torch with hollow electrodes

    Hur, Min; Kim, Keun Su; Hong, Sang Hee

    2003-01-01

    The operational features and thermal plasma characteristics of a plasma torch with hollow electrodes are investigated based on their dependence on input current, gas flow rate and electrode diameter when air is used as a plasma gas. A plasma torch with a hollow cathode and anode has been designed and fabricated, and the arc voltages and thermal efficiencies are measured from its discharge. The newly modified similarity criteria are derived from the measured data related to torch performances. From the fact that these criteria successfully describe both the arc voltage and thermal efficiency behaviour of the torch, depending on its operating and geometrical parameters, it is proved that they can be usefully applied to the design and operation of high power torches. For the numerical modelling of the interior region of the torch, a cold flow analysis is employed along with a simplified balance equation of the Lorentz and gas dynamic drag forces in order to determine a cathode spot position on the cathode surface. The validity of this method is confirmed by comparison of the calculated and measured net powers. As a practically useful result of this analysis, carried out through this numerical and experimental work, it is suggested that low input current, high gas flow rate and relatively large electrode diameter are more favourable as appropriate operating conditions of the torch for the efficient treatment of hazardous organic wastes

  3. Characteristics of membrane fouling in submerged membrane bioreactor under sub-critical flux operation.

    Su, Y C; Huang, C P; Pan, Jill R; Lee, H C

    2008-01-01

    Recently, the membrane bioreactor (MBR) process has become one of the novel technologies to enhance the performance of biological treatment of wastewater. Membrane bioreactor process uses the membrane unit to replace a sediment tank, and this can greatly enhance treatment performance. However, membrane fouling in MBR restricts its widespread application because it leads to permeate flux decline, making more frequent membrane cleaning and replacement necessary, which then increases operating and maintenance costs. This study investigated the sludge characteristics in membrane fouling under sub-critical flux operation and also assessed the effect of shear stress on membrane fouling. Membrane fouling was slow under sub-critical flux operation. However, as filamentous microbes became dominant in the reactor, membrane fouling increased dramatically due to the increased viscosity and polysaccharides. A close link was found between membrane fouling and the amount of polysaccharides in soluble EPS. The predominant resistance was the cake resistance which could be minimized by increasing the shear stress. However, the resistance of colloids and solutes was not apparently reduced by increasing shear stress. Therefore, smaller particles such as macromolecules (e.g. polysaccharides) may play an important role in membrane fouling under sub-critical flux operation.

  4. SWIFT BAT Loop Heat Pipe Thermal System Characteristics and Ground/Flight Operation Procedure

    Choi, Michael K.

    2003-01-01

    The SWIFT Burst Alert Telescope (BAT) Detector Array has a total power dissipation of 208 W. To meet the stringent temperature gradient and thermal stability requirements in the normal operational mode, and heater power budget in both the normal operational and safehold modes, the Detector Array is thermally well coupled to eight constant conductance heat pipes (CCHPs) embedded in the Detector Array Plate (DAP), and two loop heat pipes (LHPs) transport heat fiom the CCHPs to a radiator. The CCHPs have ammonia as the working fluid and the LHPs have propylene as the working fluid. Precision heater controllers, which have adjustable set points in flight, are used to control the LHP compensation chamber and Detector Array XA1 ASIC temperatures. The radiator has the AZ-Tek AZW-LA-II low-alpha white paint as the thermal coating and is located on the anti-sun side of the spacecraft. This paper presents the characteristics, ground operation and flight operation procedures of the LHP thermal system.

  5. The influence of personal characteristics on the resilience of operating room nurses: a predictor study.

    Gillespie, Brigid M; Chaboyer, Wendy; Wallis, Marianne

    2009-07-01

    Resilience in the workplace has been described as a means of facilitating adaptation in stressful environments, and therefore has application in nursing contexts. However, little research has examined how personal characteristics such as age, nursing experience and education contribute to resilience in clinical environments such as the operating room (OR). First to identify the level of resilience, and second, investigate whether age, experience and education contribute to resilience in an Australian sample of OR nurses. A predictive survey design was used. A random sample of 1430 nurses who were members of the Australian College of Operating Room Nurses association were surveyed. The survey included the 25-item Connor-Davidson Resilience Scale, and demographic questions. A standard regression model tested the hypothesis that age, years of OR experience and education contributed to resilience in OR nurses. A total of 735 (51.4%) completed, usable surveys were returned. Pearson's correlations demonstrated modest but statistically significant associations between age (presilience. In the multiple regression model, only years of OR experience predicted resilience (presilience. In OR nurses, resilience appears to be predicted by other attributes and is not necessarily dependent on an individual's personal characteristics. Thus, recruitment to the OR should not be based on the conventional notion that an older nursing workforce will have greater longevity and hence be more stable. If younger, less experienced nurses are adequately supported, they may thrive in the OR environment.

  6. Improvement of the environmental and operational characteristics of vehicles through decreasing the motor fuel density.

    Magaril, Elena

    2016-04-01

    The environmental and operational characteristics of motor transport, one of the main consumers of motor fuel and source of toxic emissions, soot, and greenhouse gases, are determined to a large extent by the fuel quality which is characterized by many parameters. Fuel density is one of these parameters and it can serve as an indicator of fuel quality. It has been theoretically substantiated that an increased density of motor fuel has a negative impact both on the environmental and operational characteristics of motor transport. The use of fuels with a high density leads to an increase in carbonization within the engine, adversely affecting the vehicle performance and increasing environmental pollution. A program of technological measures targeted at reducing the density of the fuel used was offered. It includes a solution to the problem posed by changes in the refining capacities ratio and the temperature range of gasoline and diesel fuel boiling, by introducing fuel additives and adding butanes to the gasoline. An environmental tax has been developed which allows oil refineries to have a direct impact on the production of fuels with improved environmental performance, taking into account the need to minimize the density of the fuel within a given category of quality.

  7. Model Optimization Identification Method Based on Closed-loop Operation Data and Process Characteristics Parameters

    Zhiqiang GENG

    2014-01-01

    Full Text Available Output noise is strongly related to input in closed-loop control system, which makes model identification of closed-loop difficult, even unidentified in practice. The forward channel model is chosen to isolate disturbance from the output noise to input, and identified by optimization the dynamic characteristics of the process based on closed-loop operation data. The characteristics parameters of the process, such as dead time and time constant, are calculated and estimated based on the PI/PID controller parameters and closed-loop process input/output data. And those characteristics parameters are adopted to define the search space of the optimization identification algorithm. PSO-SQP optimization algorithm is applied to integrate the global search ability of PSO with the local search ability of SQP to identify the model parameters of forward channel. The validity of proposed method has been verified by the simulation. The practicability is checked with the PI/PID controller parameter turning based on identified forward channel model.

  8. Modeling the effect of operator and passenger characteristics on the fatality risk of motorcycle crashes.

    Tavakoli Kashani, Ali; Rabieyan, Rahim; Besharati, Mohammad Mehdi

    2016-01-01

    In Iran more than 25% of crash fatalities belong to motorcycle operators and passengers in the recent years, from which about 20% are related to passenger fatalities. The aim of this study was to investigate the motorcycle operator and passenger characteristics as well as other contributory factors that may affect the fatality risk of motorcyclists involved in traffic crashes. To this end, motorcycle crash data between 2009 and 2012 was extracted from Iran traffic crash database and a logistic regression analysis was performed to obtain odds ratio estimates for each of the study variables. The fatality risk of motorcyclists has a direct relationship with the number of pillion passengers carried. Results also indicate that the amount of increase in the likelihood of having a fatality in a motorcycles crash is considerably higher when the operator is accompanied by a male passenger of the same age. Furthermore, results showed that if the crash is occurred in the darkness, on curves, in rural areas and on highways, then the crash would be more likely to be fatal. Moreover, the head-on collisions, older operators, unlicensed operators and not using a safety helmet were found to increase the likelihood of a fatality in a motorcycle crash. Preventative measures such as, imposing stricter rules regarding safety helmet usage and confining the number of pillion passengers to one, might be implemented to reduce the fatality risk in motorcycle crashes. In addition, more appropriate infrastructures for penalizing offending motorcyclists could also reduce the frequency of law violations such as not wearing helmet or riding without motorcycle license, which in turn, would result into a reduction in the fatality risk of motorcycle crashes. © 2016 KUMS, All rights reserved.

  9. Reactor core modeling practice: Operational requirements, model characteristics, and model validation

    Zerbino, H.

    1997-01-01

    The physical models implemented in power plant simulators have greatly increased in performance and complexity in recent years. This process has been enabled by the ever increasing computing power available at affordable prices. This paper describes this process from several angles: First the operational requirements which are more critical from the point of view of model performance, both for normal and off-normal operating conditions; A second section discusses core model characteristics in the light of the solutions implemented by Thomson Training and Simulation (TT and S) in several full-scope simulators recently built and delivered for Dutch, German, and French nuclear power plants; finally we consider the model validation procedures, which are of course an integral part of model development, and which are becoming more and more severe as performance expectations increase. As a conclusion, it may be asserted that in the core modeling field, as in other areas, the general improvement in the quality of simulation codes has resulted in a fairly rapid convergence towards mainstream engineering-grade calculations. This is remarkable performance in view of the stringent real-time requirements which the simulation codes must satisfy as well as the extremely wide range of operating conditions that they are called upon to cover with good accuracy. (author)

  10. Operational characteristics and analysis of the immersed-Bz diode on RITS-3.

    Bruner, Nichelle " Nicki" ; Oliver, Bryan Velten; Portillo, Salvador; Puetz, Elizabeth A.; Johnston, Mark D.; Welch, Dale Robert; Rose, David Vincent; Cooper, G.M. (AWE, Aldermaston, Reading, United Kingdom); McLean, John (AWE, Aldermaston, Reading, United Kingdom); Rovang, Dean Curtis; Maenchen, John Eric

    2006-02-01

    The immersed-B{sub z} diode is being developed as a high-brightness, flash x-ray radiography source. This diode is a foil-less electron-beam diode with a long, thin, needle-like cathode inserted into the bore of a solenoid. The solenoidal magnetic field guides the electron beam emitted from the cathode to the anode while maintaining a small beam radius. The electron beam strikes a thin, high-atomic-number anode and produces bremsstrahlung. We report on an extensive series of experiments where an immersed-B{sub z} diode was fielded on the RITS-3 pulsed power accelerator, a 3-cell inductive voltage generator that produced peak voltages between 4 and 5 MV, {approx}140 kA of total current, and power pulse widths of {approx}50 ns. The diode is a high impedance device that, for these parameters, nominally conducts {approx}30 kA of electron beam current. Diode operating characteristics are presented and two broadly characterized operating regimes are identified: a nominal operating regime where the total diode current is characterized as classically bipolar and an anomalous impedance collapse regime where the total diode current is in excess of the bipolar limit and up to the full accelerator current. The operating regimes are approximately separated by cathode diameters greater than {approx}3 mm for the nominal regime and less than {approx} 3 mm for the anomalous impedance collapse regime. This report represents a compilation of data taken on RITS-3. Results from key parameter variations are presented in the main body of the report and include cathode diameter, anode-cathode gap, and anode material. Results from supporting parameter variations are presented in the appendices and include magnetic field strength, prepulse, pressure and accelerator variations.

  11. Combination study of operation characteristics and heat transfer mechanism for pulsating heat pipe

    Cui, Xiaoyu; Zhu, Yue; Li, Zhihua; Shun, Shende

    2014-01-01

    Pulsating heat pipe (PHP) is becoming a promising heat transfer device for the application like electronics cooling. However, due to its complicated operation mechanism, the heat transfer properties of the PHP still have not been fully understood. This study experimentally investigated on a closed-loop PHP charged with four types of working fluids, deionized water, methanol, ethanol and acetone. Combined with the visualization experimental results from the open literature, the operation characteristics and the corresponding heat transfer mechanisms for different heat inputs (5 W up to 100 W) and different filling ratios (20% up to 95%) have been presented and elaborated. The results show that heat-transfer mechanism changed with the transition of operation patterns; before valid oscillation started, the thermal resistance was not like that described in the open literature where it decreased almost linearly, but would rather slowdown descending or even change into rise first before further decreasing (i.e. an inflection point existed); when the heat input further increased to certain level, e.g. 65 W or above, there presented a limit of heat-transfer performance which was independent of the types of working fluids and the filling ratios, but may be related to the structure, the material, the size and the inclination of the PHP. - Highlights: •The thermal mechanisms altered accordingly with the operation features in the PHP. •Unlike conventional heat pipes, continuous temperature soaring would not happen in the PHP. •Before the oscillation start-up, there existed a heat-transfer limit for the relatively stagnated flow in the PHP. •A limit of thermal performance existed in the PHP at relatively high heat inputs

  12. Operational characteristics and analysis of the immersed-Bz diode on RITS-3

    Bruner, Nichelle

    2006-01-01

    The immersed-B z diode is being developed as a high-brightness, flash x-ray radiography source. This diode is a foil-less electron-beam diode with a long, thin, needle-like cathode inserted into the bore of a solenoid. The solenoidal magnetic field guides the electron beam emitted from the cathode to the anode while maintaining a small beam radius. The electron beam strikes a thin, high-atomic-number anode and produces bremsstrahlung. We report on an extensive series of experiments where an immersed-B z diode was fielded on the RITS-3 pulsed power accelerator, a 3-cell inductive voltage generator that produced peak voltages between 4 and 5 MV, ∼140 kA of total current, and power pulse widths of ∼50 ns. The diode is a high impedance device that, for these parameters, nominally conducts ∼30 kA of electron beam current. Diode operating characteristics are presented and two broadly characterized operating regimes are identified: a nominal operating regime where the total diode current is characterized as classically bipolar and an anomalous impedance collapse regime where the total diode current is in excess of the bipolar limit and up to the full accelerator current. The operating regimes are approximately separated by cathode diameters greater than ∼3 mm for the nominal regime and less than ∼ 3 mm for the anomalous impedance collapse regime. This report represents a compilation of data taken on RITS-3. Results from key parameter variations are presented in the main body of the report and include cathode diameter, anode-cathode gap, and anode material. Results from supporting parameter variations are presented in the appendices and include magnetic field strength, prepulse, pressure and accelerator variations

  13. Clinical microbiology in the intensive care unit: Strategic and operational characteristics

    Bhattacharya S

    2010-01-01

    Full Text Available Infection is a major cause of morbidity and mortality among patients admitted in intensive care units (ICUs. The application of the principles and the practice of Clinical Microbiology for ICU patients can significantly improve clinical outcome. The present article is aimed at summarising the strategic and operational characteristics of this unique field where medical microbiology attempts to venture into the domain of direct clinical care of critically ill patients. The close and strategic partnership between clinical microbiologists and intensive care specialists, which is essential for this model of patient care have been emphasized. The article includes discussions on a variety of common clinical-microbiological problems faced in the ICUs such as ventilator-associated pneumonia, blood stream infections, skin and soft tissue infection, UTI, infection control, besides antibiotic management.

  14. Receiver operating characteristic (ROC) curves: review of methods with applications in diagnostic medicine

    Obuchowski, Nancy A.; Bullen, Jennifer A.

    2018-04-01

    Receiver operating characteristic (ROC) analysis is a tool used to describe the discrimination accuracy of a diagnostic test or prediction model. While sensitivity and specificity are the basic metrics of accuracy, they have many limitations when characterizing test accuracy, particularly when comparing the accuracies of competing tests. In this article we review the basic study design features of ROC studies, illustrate sample size calculations, present statistical methods for measuring and comparing accuracy, and highlight commonly used ROC software. We include descriptions of multi-reader ROC study design and analysis, address frequently seen problems of verification and location bias, discuss clustered data, and provide strategies for testing endpoints in ROC studies. The methods are illustrated with a study of transmission ultrasound for diagnosing breast lesions.

  15. Optimal algorithm for automatic detection of microaneurysms based on receiver operating characteristic curve

    Xu, Lili; Luo, Shuqian

    2010-11-01

    Microaneurysms (MAs) are the first manifestations of the diabetic retinopathy (DR) as well as an indicator for its progression. Their automatic detection plays a key role for both mass screening and monitoring and is therefore in the core of any system for computer-assisted diagnosis of DR. The algorithm basically comprises the following stages: candidate detection aiming at extracting the patterns possibly corresponding to MAs based on mathematical morphological black top hat, feature extraction to characterize these candidates, and classification based on support vector machine (SVM), to validate MAs. Feature vector and kernel function of SVM selection is very important to the algorithm. We use the receiver operating characteristic (ROC) curve to evaluate the distinguishing performance of different feature vectors and different kernel functions of SVM. The ROC analysis indicates the quadratic polynomial SVM with a combination of features as the input shows the best discriminating performance.

  16. Operating characteristics of radiation-hardened silicon pixel detectors for the CMS experiment

    Hyosung, Cho

    2002-01-01

    The Compact Muon Solenoid (CMS) experiment at the CERN Large Hadron Collider (LHC) will have forward silicon pixel detectors as its innermost tracking device. The pixel devices will be exposed to the harsh radiation environment of the LHC. Prototype silicon pixel detectors have been designed to meet the specification of the CMS experiment. No guard ring is required on the n/sup +/ side, and guard rings on the p/sup +/ side are always kept active before and after type inversion. The whole n/sup +/ side is grounded and connected to readout chips, which greatly simplifies detector assembling and improves the stability of bump-bonded readout chips on the n/sup +/ side. Operating characteristics such as the leakage current, the full depletion voltage, and the potential distributions over guard rings were tested using standard techniques. The tests are discussed in this paper. (9 refs).

  17. Receiver Operator Characteristic Tools Graphic User Interface Extension for R Commander

    Daniel Corneliu LEUCUŢA

    2015-12-01

    Full Text Available Background: Receiver Operator Characteristic (ROC curve, is a graphical plot which presents the performance of a binary classifier when the discrimination cutoff is varied. The aim of this work was to create an extension for R Commander that offers a graphical user interface for Receiver Operator Characteristic tools provided by several existing command line accessible packages like pROC and ROCR. Material and Methods: The extension was built and tested with R version 3.2.0 and R Commander 2.1-7. Results: We built an extension called RcmdrPlugin.ROC that we uploaded on the CRAN servers. The extension adds a new menu called ROC, along with two submenus pROC and ROCR that broadly corresponds to commands available to access the functions of these packages. The pROC menu offers several commands: to plot a ROC curve for a dataset or for a logistic regression model, to compare paired and unpaired ROC curves, each providing the following tabs: General (to select the variables for the analysis, and options for switching cases with controls; Smoothing (allowing the user to select different types of smoothing – binominal, density, distributions like normal, lognormal, ...; AUC (to specify the partial area under the curve (AUC options, CI (to select the options of confidence intervals (CI – the level, computing method: DeLong, bootstrap, ...; Plot (for the plotting options. The ROCR dialogue window offers more options in choosing the performance measures for the plot. Conclusion: The RcmdrPlugin.ROC extension helps less advanced users of R accessing ROC tools in a friendly graphical user interface.

  18. Operational, professional, and business characteristics of radiology groups in the United States.

    Sunshine, J H; Bansal, S

    1992-05-01

    To learn the main operational, professional, and business characteristics of U.S. radiology group practices, researchers at the American College of Radiology surveyed these groups. Major findings included the following: Approximately 30% of groups provide only diagnostic radiologic services, a similar percentage provides only radiation therapy for oncologic patients, and the remainder provides both types of services. Forty-one percent of groups practice only in hospitals, 11% practice only in an office, and 48% practice in both settings. Diagnostic-only practices average 10,000-12,000 procedures per full-time equivalent radiologist per year. Groups typically require new members to be part of the group for almost 3 years before they become full partners. Formal call schedules are nearly universal among radiology groups. Groups are becoming increasingly involved with health maintenance organizations and other "alternative delivery systems," but fee-for-service remains by far the dominant source of groups' revenue. Most studied characteristics of groups are changing relatively slowly, and trends are generally toward increasing formalization of arrangements.

  19. Operational characteristics of hybrid-type SFCL with closed and open cores

    Cho, Y.S.; Lee, N.Y.; Choi, H.S.; Chung, D.C.; Lim, S.H.

    2007-01-01

    We investigated the operational characteristics of the hybrid-type superconducting fault current limiter (SFCL) with the closed and the open cores, which induced the variation of the magnetic flux between the primary and the secondary windings. The experimental set-up of the hybrid-type SFCL with the closed and the open cores were prepared and the experimental analyses for the current limiting characteristics were performed. The peak value of the fault current in the hybrid-type SFCL with the open core was higher than that of the closed core at the first cycle after fault occurrence. However, in the case of the hybrid-type SFCL with the open core, the limiting current level after fault occurrence was decreased less than that of the hybrid-type SFCL with the closed core, because the magnetic leakage reluctance of the open core was higher than that of the closed core. The quench time (T q ) and the arrival time (T a ) for the peak voltage (V SC ) in the hybrid-type SFCL with the closed core were faster than that of the hybrid-type SFCL with the open core due to the increase of the mutual flux. We verified that the consumption power in the hybrid-type SFCL with the open core was larger owing to the increase of leakage flux by the reduction of mutual inductance between primary and secondary windings

  20. Experimental apparatus and its operational characteristics for MHD rotating machine with superconducting rotor

    Katsurai, Makoto; Karasaki, Takashi; Sekiguchi, Tadashi; Matsuda, Shoji; Ichikawa, Hayao.

    1976-01-01

    This paper presents the construction and operational characteristics of the experimental apparatus of MHD rotating machine with superconducting rotor, which has the electromechanical energy conversion function based on the inductive interactions between travelling magnetic field produced by the rotor and MHD working fluid. The machine consists of a rotating-dewar type superconducting rotor and a coaxially rotating metal cylinder which simulates the liquid metal MHD working fluid, and the both of them are driven separately by speed-controlled driving motors. The superconducting magnets installed in the rotor has the 8 shaped winding whose outer diameter is 11 cm and hight is 11 cm, and with the excitation current of 200 A (rating), it produces screw type magnetic field in the inductive interaction region of the cylinder with the peak value of 0.2 Wb/m 2 , whereas the average field strength reaches almost 4 Wb/m 2 inside the winding. In this condition, mutual interaction force is 30 N in the peripheral direction and 8 N in the axial direction and the total driving power of motors is 1,300 W when the relative rotation speed of the rotor and the cylinder is 800 rpm. Observed characteristics of this machine are for the most part in agreement with those estimated by the theoretical analysis. (auth.)

  1. Likelihood-Based Clustering of Meta-Analytic SROC Curves

    Holling, Heinz; Bohning, Walailuck; Bohning, Dankmar

    2012-01-01

    Meta-analysis of diagnostic studies experience the common problem that different studies might not be comparable since they have been using a different cut-off value for the continuous or ordered categorical diagnostic test value defining different regions for which the diagnostic test is defined to be positive. Hence specificities and…

  2. Impact of signal scattering and parametric uncertainties on receiver operating characteristics

    Wilson, D. Keith; Breton, Daniel J.; Hart, Carl R.; Pettit, Chris L.

    2017-05-01

    The receiver operating characteristic (ROC curve), which is a plot of the probability of detection as a function of the probability of false alarm, plays a key role in the classical analysis of detector performance. However, meaningful characterization of the ROC curve is challenging when practically important complications such as variations in source emissions, environmental impacts on the signal propagation, uncertainties in the sensor response, and multiple sources of interference are considered. In this paper, a relatively simple but realistic model for scattered signals is employed to explore how parametric uncertainties impact the ROC curve. In particular, we show that parametric uncertainties in the mean signal and noise power substantially raise the tails of the distributions; since receiver operation with a very low probability of false alarm and a high probability of detection is normally desired, these tails lead to severely degraded performance. Because full a priori knowledge of such parametric uncertainties is rarely available in practice, analyses must typically be based on a finite sample of environmental states, which only partially characterize the range of parameter variations. We show how this effect can lead to misleading assessments of system performance. For the cases considered, approximately 64 or more statistically independent samples of the uncertain parameters are needed to accurately predict the probabilities of detection and false alarm. A connection is also described between selection of suitable distributions for the uncertain parameters, and Bayesian adaptive methods for inferring the parameters.

  3. Characteristics of magnetically insulated diode in a multi-shot operation

    Chishiro, E; Masugata, K; Yatsui, K [Nagaoka Univ. of Technology (Japan). Laboratory of Beam Technology

    1997-12-31

    The beam characteristics in a multi-shot operation were evaluated. The MID utilized in the experiment is a racetrack type diode, where flat anode and cathode electrodes are utilized. On the anode, a polyethylene sheet of 1 mm thickness is attached as an ion source. The MID is successively operated without breaking the vacuum. An ion current density (J{sub i}) of 350 A/cm{sup 2} is observed at the first shot when the diode gap is 5 mm. The value decreases with increasing number of shots and at the 7th shot, J{sub i} is less than 150 A/cm{sup 2}. After 7 shots, the anode surface is inspected and found to be covered with stuck matter of metallic materials such as Zn, Al, Fe, Cu. These materials seem to be produced by the ablation of the MID electrode. By eliminating the stuck matter from the surface, J{sub i} is recovered to the initial value. The decrease in J{sub i} is due to the fact that the anode is covered with the stuck matter, which prevents the growth of anode plasma. (author). 6 figs., 8 refs.

  4. Condenser design optimization and operation characteristics of a novel miniature loop heat pipe

    Wan Zhenping; Wang Xiaowu; Tang Yong

    2012-01-01

    Highlights: ► A novel miniature LHP (mLHP) system was presented. ► Optimal design of condenser was considered. ► The heat transfer performance was investigated experimentally. - Abstract: Loop heat pipe (LHP) is a promising means for electronics cooling since LHP is a exceptionally efficient heat transfer device. In this paper, a novel miniature LHP (mLHP) system is presented and optimal design of condenser is considered seeing that evaporators have been able to handle very high-heat fluxes with low-heat transfer resistances since most of the previous researchers focused on the evaporator of mLHP. The arrayed pins were designed and machined out on the bottom of condenser to enhance condensation heat transfer. The parameters of the arrayed pins, including layout, cross-section shape and area, were optimized by finite element analysis. Tests were carried out on the mLHP with a CPU thermal simulator using forced air convection condenser cooling to validate the optimization. The operation characteristics of the mLHP with optimal design parameters of condenser were investigated experimentally. The experimental results show that the mLHP can reject head load 200 W while maintaining the cooled object temperatures below 100 °C, and for a variable power applied to the evaporator, the system presents reliable startups and continuous operation.

  5. Operating characteristics of a new ion source for KSTAR neutral beam injection system.

    Kim, Tae-Seong; Jeong, Seung Ho; Chang, Doo-Hee; Lee, Kwang Won; In, Sang-Ryul

    2014-02-01

    A new positive ion source for the Korea Superconducting Tokamak Advanced Research neutral beam injection (KSTAR NBI-1) system was designed, fabricated, and assembled in 2011. The characteristics of the arc discharge and beam extraction were investigated using hydrogen and helium gas to find the optimum operating parameters of the arc power, filament voltage, gas pressure, extracting voltage, accelerating voltage, and decelerating voltage at the neutral beam test stand at the Korea Atomic Energy Research Institute in 2012. Based on the optimum operating condition, the new ion source was then conditioned, and performance tests were primarily finished. The accelerator system with enlarged apertures can extract a maximum 65 A ion beam with a beam energy of 100 keV. The arc efficiency and optimum beam perveance, at which the beam divergence is at a minimum, are estimated to be 1.0 A/kW and 2.5 uP, respectively. The beam extraction tests show that the design goal of delivering a 2 MW deuterium neutral beam into the KSTAR Tokamak plasma is achievable.

  6. Analysis of the operational performance and efficiency characteristic for photovoltaic system in Hong Kong

    Li, Danny H.W.; Cheung, Gary H.W.; Lam, Joseph C.

    2005-01-01

    The applications of photovoltaic (PV) systems have become more widespread in both developed and developing countries. The most critical exercise in designing a PV system is the determination of the optimum size of the solar panel and the battery capacity to meet the load demand with acceptable reliability. The amount of power generated by a PV system strongly depends on the availability of solar insolation at the required location. Also, the efficiency of a PV system is influenced considerably by a number of climatic variables, such as solar irradiance availability and ambient temperature. The technical information is provided for standard test conditions that may never occur in practice. Reliable knowledge of the performance of PV systems under actual operating conditions is essential for correct product selection and accurate performance prediction. This paper investigates the operational performance and efficiency characteristic of a small PV system installed at the City University of Hong Kong. The solar data and the power generated by the PV system are systematically recorded and analysed. The findings provide technical data in different months for designers and engineers to assess and size PV systems

  7. Operational characteristics of nuclear power plants - modelling of operational safety; Pogonske karakteristike nuklearnih elektrana - modelsko izucavanje pogonske sigurnosti

    Studovic, M [Masinski fakultet, Beograd (Yugoslavia)

    1984-07-01

    By operational experience of nuclear power plants and realize dlevel of availability of plant, systems and componenst reliabiliuty, operational safety and public protection, as a source on nature of distrurbances in power plant systems and lessons drawn by the TMI-2, in th epaper are discussed: examination of design safety for ultimate ensuring of safe operational conditions of the nuclear power plant; significance of the adequate action for keeping proess parameters in prescribed limits and reactor cooling rquirements; developed systems for measurements detection and monitoring all critical parameters in the nuclear steam supply system; contents of theoretical investigation and mathematical modeling of the physical phenomena and process in nuclear power plant system and components as software, supporting for ensuring of operational safety and new access in staff education process; program and progress of the investigation of some physical phenomena and mathematical modeling of nuclear plant transients, prepared at faculty of mechanical Engineering in Belgrade. (author)

  8. COMBUSTION CHARACTERISTICS OF DIESEL ENGINE OPERATING ON JATROPHA OIL METHYL ESTER

    Doddayaraganalu Amasegoda Dhananjaya

    2010-01-01

    Full Text Available Fuel crisis because of dramatic increase in vehicular population and environmental concerns have renewed interest of scientific community to look for alternative fuels of bio-origin such as vegetable oils. Vegetable oils can be produced from forests, vegetable oil crops, and oil bearing biomass materials. Non-edible vegetable oils such as jatropha oil, linseed oil, mahua oil, rice bran oil, karanji oil, etc., are potentially effective diesel substitute. Vegetable oils have reasonable energy content. Biodiesel can be used in its pure form or can be blended with diesel to form different blends. It can be used in diesel engines with very little or no engine modifications. This is because it has combustion characteristics similar to petroleum diesel. The current paper reports a study carried out to investigate the combustion, performance and emission characteristics of jatropha oil methyl ester and its blend B20 (80% petroleum diesel and 20% jatropha oil methyl ester and diesel fuel on a single-cylinder, four-stroke, direct injections, water cooled diesel engine. This study gives the comparative measures of brake thermal efficiency, brake specific energy consumption, smoke opacity, HC, NOx, ignition delay, cylinder peak pressure, and peak heat release rates. The engine performance in terms of higher thermal efficiency and lower emissions of blend B20 fuel operation was observed and compared with jatropha oil methyl ester and petroleum diesel fuel for injection timing of 20° bTDC, 23° bTDC and 26° bTDC at injection opening pressure of 220 bar.

  9. Operating Characteristics of a Continuous Two-Stage Bubbling Fluidized-Bed Process

    Youn, Pil-Sang; Choi, Jeong-Hoo

    2014-01-01

    Flow characteristics and the operating range of gas velocity was investigated for a two-stage bubbling fluidized-bed (0.1 m-i.d., 1.2 m-high) that had continuous solids feed and discharge. Solids were fed in to the upper fluidized-bed and overflowed into the bed section of the lower fluidized-bed through a standpipe (0.025 m-i.d.). The standpipe was simply a dense solids bed with no mechanical or non-mechanical valves. The solids overflowed the lower bed for discharge. The fluidizing gas was fed to the lower fluidized-bed and the exit gas was also used to fluidize the upper bed. Air was used as fluidizing gas and mixture of coarse (<1000 μm in diameter and 3090 kg/m 3 in apparent density) and fine (<100 μm in diameter and 4400 kg/m 3 in apparent density) particles were used as bed materials. The proportion of fine particles was employed as the experimental variable. The gas velocity of the lower fluidized-bed was defined as collapse velocity in the condition that the standpipe was emptied by upflow gas bypassing from the lower fluidized-bed. It could be used as the maximum operating velocity of the present process. The collapse velocity decreased after an initial increase as the proportion of fine particles increased. The maximum took place at the proportion of fine particles 30%. The trend of the collapse velocity was similar with that of standpipe pressure drop. The collapse velocity was expressed as a function of bulk density of particles and voidage of static bed. It increased with an increase of bulk density, however, decreased with an increase of voidage of static bed

  10. IMPROVEMENT OF BUS OPERATIONAL CHARACTERISTICS WHILE USING INTEGRATED CONTROL OF SUSPENSION AND TRANSMISSION

    V. V. Mikhailau

    2016-01-01

    Full Text Available Semi-natural tests for active pneumatic suspension of a 18-tonne tourist bus with the system of automatic body stabilization of the mobile machine and feed-back coupling according to kinematics parameter. The test have been executed in the cases when the bus is stocked with an automatic hydro-mechanical transmission in the process of speed picking up, gear-changing or road braking which is assigned by accidental road humps. A computer simulation of dynamic structures in combination with virtual devices and real objects (HIL – Hardware-in-the-Loop Simulation has been carried in the paper. Personal computers, software, programmed logic controller, frequency generator, solenoid-operated valve have been used for the investigation process. The paper proposes an unconventional method for improvement operational characteristics which is based on integrated control of a suspension and automatic hydro-mechanical transmission. A mathematical model includes systems of automatic transmission, suspension and module for generation of accidental road humps. The model has been considered as a basis for semi-natural laboratory bench with industrially-manufactured controller, other components of automatic systems and standard control organs. The most efficient method for body stabilization is control of the suspension according to the parameter of angular rate during vertical turn of an automobile’s center line with a turning point in the center of mass. The developed algorithm and stabilization system according to angular rate of body’s center line turning have made it possible to improve dynamics of the bus while making gear-changing and to reduce fuel consumption during starting-up and speed picking-up processes. During the braking process such system simultaneously decreases oscillation amplitude of some parameters more than two-fold.

  11. Hydroclimatic Characteristics of the 2012–2015 California Drought from an Operational Perspective

    Minxue He

    2017-01-01

    Full Text Available California experienced an extraordinary drought from 2012–2015 (which continues into 2016. This study, from an operational perspective, reviewed the development of this drought in a hydroclimatic framework and examined its characteristics at different temporal and spatial scales. Observed and reconstructed operational hydrologic indices and variables widely used in water resources planning and management at statewide and (hydrologic regional scales were employed for this purpose. Parsimonious metrics typically applied in drought assessment and management practices including the drought monitor category, percent of average, and rank were utilized to facilitate the analysis. The results indicated that the drought was characterized by record low snowpack (statewide four-year accumulated deficit: 280%-of-average, exceptionally low April-July runoff (220%-of-average deficit, and significantly below average reservoir storage (93%-of-average deficit. During the period from 2012–2015, in general, water year 2015 stood out as the driest single year; 2014–2015 was the driest two-year period; and 2013–2015 tended to be the driest three-year period. Contrary to prior studies stating that the 2012–2015 drought was unprecedented, this study illustrated that based on eight out of 28 variables, the 2012–2015 drought was not without precedent in the record period. Spatially, on average, the South Coast Region, the Central Coast Region, the Tulare Region, and the San Joaquin Region generally had the most severe drought conditions. Overall, these findings are highly meaningful for water managers in terms of making better informed adaptive management plans.

  12. Incidence, characteristics and management of pain in one operational area of medical emergency teams.

    Kosiński, Sylweriusz; Bryja, Magdalena; Wojtaszowicz, Rafał; Górka, Andrzej

    2014-01-01

    Experience of pain associated with both chronic as well as acute medical conditions is a main cause for call for ambulance. The aim of this study was to establish both frequency and characteristics of pain reported by patients treated in pre-hospital environment in a single operational area. The supplementary goal was an analysis of methods of pain alleviation applied by medical personnel in the above described scenario. The written documentation of 6 months of year 2009 provided by doctor-manned as well as paramedic-only ambulances operating in Tatra county, Małopolska, Poland was analyzed. Medical personnel inquired about pain experienced in 57.4% of cases, 10-point numerical rating scale was used in 22.3% of patients. Pain was reported by 43.8% of patients, the most frequent reasons of experienced pain were trauma and cardiovascular diseases. In almost half of the cases pain was referred to the areas of chest and abdomen. Non-traumatic pain was reported by 47.7% of patients, post-traumatic in 41.3% of cases, 11% of subjects reported ischemic chest pain. 42.3% of pain-reporting patients received some form of analgesia, yet only 3% of subjects in this group received opiates. Personnel of paramedic-only ambulances tended to use pain intensity scale more often (P < 0.01), yet administered pain alleviating drugs noticeably less often than the doctor-manned teams (P < 0.01). The use of pain alleviating drugs, opiates especially, was inadequate in proportion to frequency and intensity of pain reported by patients. General, nation-wide standards of pain measurement and treatment in pre-hospital rescue are suggested as a means to improve the efficacy of pain reduction treatment.

  13. Investigation on Flame Characteristics and Burner Operability Issues of Oxy-Fuel Combustion

    Choudhuri, Ahsan [Univ. Of Texas, El Paso, TX (United States)

    2013-09-30

    Oxy-fuel combustion has been used previously in a wide range of industrial applications. Oxy- combustion is carried out by burning a hydrocarbon fuel with oxygen instead of air. Flames burning in this configuration achieve higher flame temperatures which present opportunities for significant efficiency improvements and direct capture of CO2 from the exhaust stream. In an effort to better understand and characterize the fundamental flame characteristics of oxy-fuel combustion this research presents the experimental measurements of flame stability of various oxyfuel flames. Effects of H2 concentration, fuel composition, exhaust gas recirculation ratio, firing inputs, and burner diameters on the flame stability of these fuels are discussed. Effects of exhaust gas recirculation i.e. CO2 and H2O (steam) acting as diluents on burner operability are also presented. The roles of firing input on flame stability are then analyzed. For this study it was observed that many oxy-flames did not stabilize without exhaust gas recirculation due to their higher burning velocities. In addition, the stability regime of all compositions was observed to decrease as the burner diameter increased. A flashback model is also presented, using the critical velocity gradient gF) values for CH4-O2-CO2 flames. The second part of the study focuses on the experimental measurements of the flow field characteristics of premixed CH4/21%O2/79%N2 and CH4/38%O2/72%CO2 mixtures at constant firing input of 7.5 kW, constant, equivalence ratio of 0.8, constant swirl number of 0.92 and constant Reynolds Numbers. These measurements were taken in a swirl stabilized combustor at atmospheric pressure. The flow field visualization using Particle Imaging Velocimetry (PIV) technique is implemented to make a better understanding of the turbulence characteristics of

  14. Characteristics associated with organizational independence in consumer-operated service organizations.

    Tanenbaum, Sandra J

    2011-01-01

    This research compares two types of consumer organizations in one state in order to explore the significance of organizational independence for internal structure/operations and external relationships. The first type, consumeroperated service organizations (COSOs), are independent and fully self-governing; the second are peer-support service organizations (PSSOs), which are part of larger non-consumer entities. Mail surveys were completed by COSO and PSSO directors of a geographically representative sample of organizations; telephone interviews were conducted with a sub-sample. Owing to small sample size, matched COSO-PSSO pairs were analyzed using non-parametric statistics. COSOs and PSSOs are similar in some ways, e.g., types of services provided, but significantly different on internal variables, such as budget size, and external variables, such as number of relationships with community groups. Organizational independence appears to be a significant characteristic for consumer service organizations and should be encouraged by funders and among participants. Funders might establish administrative and/or programmatic measures to support consumer organizations that are independent or moving toward independence; their participants would also benefit from the provision, by authorities or advocates, of materials to guide organizations toward, for example, 501(c)3 status.

  15. Receiver operating characteristic curve evaluation on computed radiography: an experimental study

    Yu Zixi; Wang Changyuan; Xu Yue; Xie Jindong; Zhang Menglong; Wang Jian

    2003-01-01

    Objective: To get the maximum information from computed radiography (CR) output images by changing post-processing parameters. Methods: Six experimental photos of polypropylene balls of 2.0 mm in diameter were taken by means of one time X-ray exposing on an imaging plate (IP) with different post-processing parameters including rotation amount (GA), gray gradation type (GT), rotation center (GC), shifting amount (GS), frequency rank (RN), frequency type (RT), and degree of enhancement (RE). 6 photos were viewed by three students and one radiologist on a 6000 lx illuminance viewbox. Receiver operating characteristic (ROC) curves were made by means of 5-value-differentiation method. Results: The largest mean area value (Az) below ROC curves of a low contrast experimental photo with post-processing parameters GA=1.0, GT=A, GC=1.6, GS=0.3, RN=4.0, RT=R and RE=3.0 was 0.96, and the maximum information was obtained. The smallest mean area value (Az) was 0.78 with changed post-processing parameters GA=0.8, GS=-0.2 and RE=0.5 while other parameters were not changed. The minimum information was obtained from this photo. Conclusion: In order to get the maximum information from a CR output image, the post-processing parameters should be suitably selected

  16. Employing the therapeutic operating characteristic (TOC) graph for individualised dose prescription.

    Hoffmann, Aswin L; Huizenga, Henk; Kaanders, Johannes H A M

    2013-03-07

    In current practice, patients scheduled for radiotherapy are treated according to 'rigid' protocols with predefined dose prescriptions that do not consider risk-taking preferences of individuals. The therapeutic operating characteristic (TOC) graph is applied as a decision-aid to assess the trade-off between treatment benefit and morbidity to facilitate dose prescription customisation. Historical dose-response data from prostate cancer patient cohorts treated with 3D-conformal radiotherapy is used to construct TOC graphs. Next, intensity-modulated (IMRT) plans are generated by optimisation based on dosimetric criteria and dose-response relationships. TOC graphs are constructed for dose-scaling of the optimised IMRT plan and individualised dose prescription. The area under the TOC curve (AUC) is estimated to measure the therapeutic power of these plans. On a continuous scale, the TOC graph directly visualises treatment benefit and morbidity risk of physicians' or patients' choices for dose (de-)escalation. The trade-off between these probabilities facilitates the selection of an individualised dose prescription. TOC graphs show broader therapeutic window and higher AUCs with increasing target dose heterogeneity. The TOC graph gives patients and physicians access to a decision-aid and read-out of the trade-off between treatment benefit and morbidity risks for individualised dose prescription customisation over a continuous range of dose levels.

  17. Employing the therapeutic operating characteristic (TOC) graph for individualised dose prescription

    Hoffmann, Aswin L; Huizenga, Henk; Kaanders, Johannes HAM

    2013-01-01

    In current practice, patients scheduled for radiotherapy are treated according to ‘rigid’ protocols with predefined dose prescriptions that do not consider risk-taking preferences of individuals. The therapeutic operating characteristic (TOC) graph is applied as a decision-aid to assess the trade-off between treatment benefit and morbidity to facilitate dose prescription customisation. Historical dose-response data from prostate cancer patient cohorts treated with 3D-conformal radiotherapy is used to construct TOC graphs. Next, intensity-modulated (IMRT) plans are generated by optimisation based on dosimetric criteria and dose-response relationships. TOC graphs are constructed for dose-scaling of the optimised IMRT plan and individualised dose prescription. The area under the TOC curve (AUC) is estimated to measure the therapeutic power of these plans. On a continuous scale, the TOC graph directly visualises treatment benefit and morbidity risk of physicians’ or patients’ choices for dose (de-)escalation. The trade-off between these probabilities facilitates the selection of an individualised dose prescription. TOC graphs show broader therapeutic window and higher AUCs with increasing target dose heterogeneity. The TOC graph gives patients and physicians access to a decision-aid and read-out of the trade-off between treatment benefit and morbidity risks for individualised dose prescription customisation over a continuous range of dose levels

  18. Theoretical research for natural circulation operational characteristic of ship nuclear machinery under ocean conditions

    Yan Binghuo [Department of Nuclear Science and Engineering, Naval University of Engineering, Wuhan 430033 (China)], E-mail: yanbh1986@163.com; Yu Lei [Department of Nuclear Science and Engineering, Naval University of Engineering, Wuhan 430033 (China)], E-mail: yulei301@163.com

    2009-06-15

    Based on the two-phase drift flux model and the multi-pressure nodes matrix solving method, natural circulation thermal hydraulic analysis models for the Nuclear Machinery (NM) under ocean conditions are developed. The neutron physical activities and the responses of the reactivity control systems are described by the two-group, 3-dimensional space and time dependent neutron kinetics model. Reactivity feedback is calculated by coupling the neutron physics and thermal hydraulic codes, and is tested by comparison with experiments. Using the models developed, the natural circulation operating characteristics of NM in rolling and pitching motions and the transitions between forced circulation (FC) to natural circulation (NC) are analyzed. The results show that the influence of the rolling motion increases as the rolling amplitude is increased, and as the rolling period becomes shorter. The results also show that for this NM, with the same rolling period and rolling angle, the influence of pitching motion on natural circulation is greater than that of rolling motion. Furthermore, the oscillation period for pitching motion is the same as the pitching period, while the oscillation period for rolling is one half of the rolling period. In the ocean environment, excessive flow oscillation of the natural circulation may cause the control rods to respond so frequently that the NM would not be able to realize the transition from the FC to NC steadily. However, the influence of ocean environment on the transition from NC to FC is limited.

  19. Cognitive Dysfunction after On-Pump Operations: Neuropsychological Characteristics and Optimal Core Battery of Tests

    Anna G. Polunina

    2014-01-01

    Full Text Available Postoperative cognitive dysfunction (POCD is a mild form of perioperative ischemic brain injury, which emerges as memory decline, decreased attention, and decreased concentration during several months, or even years, after surgery. Here we present results of our three neuropsychological studies, which overall included 145 patients after on-pump operations. We found that the auditory memory span test (digit span was more effective as a tool for registration of POCD, in comparison with the word-list learning and story-learning tests. Nonverbal memory or visuoconstruction tests were sensitive to POCD in patients after intraoperative opening of cardiac chambers with increased cerebral air embolism. Psychomotor speed tests (digit symbol, or TMT A registered POCD, which was characteristic for elderly atherosclerotic patients. Finally, we observed that there were significant effects of the order of position of a test on the performance on this test. For example, the postoperative performance on the core tests (digit span and digit symbol showed minimal impairment when either of these tests was administered at the beginning of testing. Overall, our data shows that the selection of tests, and the order of which these tests are administered, may considerably influence the results of studies of POCD.

  20. Operating characteristics of a qualitative troponin assay for the diagnosis of acute coronary syndrome.

    Farsi, Davood; Pishbin, Elham; Abbasi, Saeed; Hafezimoghadam, Peyman; Fathi, Marzieh; Zare, Mohammad Amin

    2013-04-01

    The troponin I serum level is widely used in acute coronary syndrome patients for their classification. The qualitative assay is faster and more available than the quantitative assay. The objective was to determine the operating characteristics of a qualitative troponin I assay compared with a quantitative method. This is a prospective observational study and patients suspected to have acute coronary syndrome were enrolled. A rapid troponin I test and a quantitative assay were carried out for each patient on arrival and 6 h after admission. A total of 262 patients were enrolled. The degree of agreement between the second rapid qualitative and quantitative troponin I was excellent (κ=0.946; 95% confidence interval, 0.903-0.989). The sensitivity, specificity, negative predictive value, and positive predictive value of the rapid qualitative troponin I test were 92.6, 100, 96.8, and 100%, respectively. In conclusion, this study reveals an excellent agreement between quantitative and qualitative bedside assays 6 h after admission in a sample of Iranian patients in the emergency department.

  1. Measuring diagnostic and predictive accuracy in disease management: an introduction to receiver operating characteristic (ROC) analysis.

    Linden, Ariel

    2006-04-01

    Diagnostic or predictive accuracy concerns are common in all phases of a disease management (DM) programme, and ultimately play an influential role in the assessment of programme effectiveness. Areas, such as the identification of diseased patients, predictive modelling of future health status and costs and risk stratification, are just a few of the domains in which assessment of accuracy is beneficial, if not critical. The most commonly used analytical model for this purpose is the standard 2 x 2 table method in which sensitivity and specificity are calculated. However, there are several limitations to this approach, including the reliance on a single defined criterion or cut-off for determining a true-positive result, use of non-standardized measurement instruments and sensitivity to outcome prevalence. This paper introduces the receiver operator characteristic (ROC) analysis as a more appropriate and useful technique for assessing diagnostic and predictive accuracy in DM. Its advantages include; testing accuracy across the entire range of scores and thereby not requiring a predetermined cut-off point, easily examined visual and statistical comparisons across tests or scores, and independence from outcome prevalence. Therefore the implementation of ROC as an evaluation tool should be strongly considered in the various phases of a DM programme.

  2. Design of a receiver operating characteristic (ROC) study of 10:1 lossy image compression

    Collins, Cary A.; Lane, David; Frank, Mark S.; Hardy, Michael E.; Haynor, David R.; Smith, Donald V.; Parker, James E.; Bender, Gregory N.; Kim, Yongmin

    1994-04-01

    The digital archiving system at Madigan Army Medical Center (MAMC) uses a 10:1 lossy data compression algorithm for most forms of computed radiography. A systematic study on the potential effect of lossy image compression on patient care has been initiated with a series of studies focused on specific diagnostic tasks. The studies are based upon the receiver operating characteristic (ROC) method of analysis for diagnostic systems. The null hypothesis is that observer performance with approximately 10:1 compressed and decompressed images is not different from using original, uncompressed images for detecting subtle pathologic findings seen on computed radiographs of bone, chest, or abdomen, when viewed on a high-resolution monitor. Our design involves collecting cases from eight pathologic categories. Truth is determined by committee using confirmatory studies performed during routine clinical practice whenever possible. Software has been developed to aid in case collection and to allow reading of the cases for the study using stand-alone Siemens Litebox workstations. Data analysis uses two methods, ROC analysis and free-response ROC (FROC) methods. This study will be one of the largest ROC/FROC studies of its kind and could benefit clinical radiology practice using PACS technology. The study design and results from a pilot FROC study are presented.

  3. ROCView: prototype software for data collection in jackknife alternative free-response receiver operating characteristic analysis

    Thompson, J; Hogg, P; Thompson, S; Manning, D; Szczepura, K

    2012-01-01

    ROCView has been developed as an image display and response capture (IDRC) solution to image display and consistent recording of reader responses in relation to the free-response receiver operating characteristic paradigm. A web-based solution to IDRC for observer response studies allows observations to be completed from any location, assuming that display performance and viewing conditions are consistent with the study being completed. The simplistic functionality of the software allows observations to be completed without supervision. ROCView can display images from multiple modalities, in a randomised order if required. Following registration, observers are prompted to begin their image evaluation. All data are recorded via mouse clicks, one to localise (mark) and one to score confidence (rate) using either an ordinal or continuous rating scale. Up to nine “mark-rating” pairs can be made per image. Unmarked images are given a default score of zero. Upon completion of the study, both true-positive and false-positive reports can be downloaded and adapted for analysis. ROCView has the potential to be a useful tool in the assessment of modality performance difference for a range of imaging methods. PMID:22573294

  4. Receiver operating characteristic analysis of age-related changes in lineup performance.

    Humphries, Joyce E; Flowe, Heather D

    2015-04-01

    In the basic face memory literature, support has been found for the late maturation hypothesis, which holds that face recognition ability is not fully developed until at least adolescence. Support for the late maturation hypothesis in the criminal lineup identification literature, however, has been equivocal because of the analytic approach that has been used to examine age-related changes in identification performance. Recently, receiver operator characteristic (ROC) analysis was applied for the first time in the adult eyewitness memory literature to examine whether memory sensitivity differs across different types of lineup tests. ROC analysis allows for the separation of memory sensitivity from response bias in the analysis of recognition data. Here, we have made the first ROC-based comparison of adults' and children's (5- and 6-year-olds and 9- and 10-year-olds) memory performance on lineups by reanalyzing data from Humphries, Holliday, and Flowe (2012). In line with the late maturation hypothesis, memory sensitivity was significantly greater for adults compared with young children. Memory sensitivity for older children was similar to that for adults. The results indicate that the late maturation hypothesis can be generalized to account for age-related performance differences on an eyewitness memory task. The implications for developmental eyewitness memory research are discussed. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Receiver operating characteristic analysis of eyewitness memory: comparing the diagnostic accuracy of simultaneous versus sequential lineups.

    Mickes, Laura; Flowe, Heather D; Wixted, John T

    2012-12-01

    A police lineup presents a real-world signal-detection problem because there are two possible states of the world (the suspect is either innocent or guilty), some degree of information about the true state of the world is available (the eyewitness has some degree of memory for the perpetrator), and a decision is made (identifying the suspect or not). A similar state of affairs applies to diagnostic tests in medicine because, in a patient, the disease is either present or absent, a diagnostic test yields some degree of information about the true state of affairs, and a decision is made about the presence or absence of the disease. In medicine, receiver operating characteristic (ROC) analysis is the standard method for assessing diagnostic accuracy. By contrast, in the eyewitness memory literature, this powerful technique has never been used. Instead, researchers have attempted to assess the diagnostic performance of different lineup procedures using methods that cannot identify the better procedure (e.g., by computing a diagnosticity ratio). Here, we describe the basics of ROC analysis, explaining why it is needed and showing how to use it to measure the performance of different lineup procedures. To illustrate the unique advantages of this technique, we also report 3 ROC experiments that were designed to investigate the diagnostic accuracy of simultaneous versus sequential lineups. According to our findings, the sequential procedure appears to be inferior to the simultaneous procedure in discriminating between the presence versus absence of a guilty suspect in a lineup.

  6. Recollection is a continuous process: Evidence from plurality memory receiver operating characteristics.

    Slotnick, Scott D; Jeye, Brittany M; Dodson, Chad S

    2016-01-01

    Is recollection a continuous/graded process or a threshold/all-or-none process? Receiver operating characteristic (ROC) analysis can answer this question as the continuous model and the threshold model predict curved and linear recollection ROCs, respectively. As memory for plurality, an item's previous singular or plural form, is assumed to rely on recollection, the nature of recollection can be investigated by evaluating plurality memory ROCs. The present study consisted of four experiments. During encoding, words (singular or plural) or objects (single/singular or duplicate/plural) were presented. During retrieval, old items with the same plurality or different plurality were presented. For each item, participants made a confidence rating ranging from "very sure old", which was correct for same plurality items, to "very sure new", which was correct for different plurality items. Each plurality memory ROC was the proportion of same versus different plurality items classified as "old" (i.e., hits versus false alarms). Chi-squared analysis revealed that all of the plurality memory ROCs were adequately fit by the continuous unequal variance model, whereas none of the ROCs were adequately fit by the two-high threshold model. These plurality memory ROC results indicate recollection is a continuous process, which complements previous source memory and associative memory ROC findings.

  7. An extension of the receiver operating characteristic curve and AUC-optimal classification.

    Takenouchi, Takashi; Komori, Osamu; Eguchi, Shinto

    2012-10-01

    While most proposed methods for solving classification problems focus on minimization of the classification error rate, we are interested in the receiver operating characteristic (ROC) curve, which provides more information about classification performance than the error rate does. The area under the ROC curve (AUC) is a natural measure for overall assessment of a classifier based on the ROC curve. We discuss a class of concave functions for AUC maximization in which a boosting-type algorithm including RankBoost is considered, and the Bayesian risk consistency and the lower bound of the optimum function are discussed. A procedure derived by maximizing a specific optimum function has high robustness, based on gross error sensitivity. Additionally, we focus on the partial AUC, which is the partial area under the ROC curve. For example, in medical screening, a high true-positive rate to the fixed lower false-positive rate is preferable and thus the partial AUC corresponding to lower false-positive rates is much more important than the remaining AUC. We extend the class of concave optimum functions for partial AUC optimality with the boosting algorithm. We investigated the validity of the proposed method through several experiments with data sets in the UCI repository.

  8. Identifying indicators of harmful and problem gambling in a Canadian sample through receiver operating characteristic analysis.

    Quilty, Lena C; Avila Murati, Daniela; Bagby, R Michael

    2014-03-01

    Many gamblers would prefer to reduce gambling on their own rather than to adopt an abstinence approach within the context of a gambling treatment program. Yet responsible gambling guidelines lack quantifiable markers to guide gamblers in wagering safely. To address these issues, the current investigation implemented receiver operating characteristic (ROC) analysis to identify behavioral indicators of harmful and problem gambling. Gambling involvement was assessed in 503 participants (275 psychiatric outpatients and 228 community gamblers) with the Canadian Problem Gambling Index. Overall gambling frequency, duration, and expenditure were able to distinguish harmful and problematic gambling at a moderate level. Indicators of harmful gambling were generated for engagement in specific gambling activities: frequency of tickets and casino; duration of bingo, casino, and investments; and expenditures on bingo, casino, sports betting, games of skill, and investments. Indicators of problem gambling were similarly produced for frequency of tickets and casino, and expenditures on bingo, casino, games of skill, and investments. Logistic regression analyses revealed that overall gambling frequency uniquely predicted the presence of harmful and problem gambling. Furthermore, frequency indicators for tickets and casino uniquely predicted the presence of both harmful and problem gambling. Together, these findings contribute to the development of an empirically based method enabling the minimization of harmful or problem gambling through self-control rather than abstinence.

  9. Screening for depressive disorders using the MASQ anhedonic depression scale: A receiver-operator characteristic analysis

    Bredemeier, Keith; Spielberg, Jeffrey M.; Silton, Rebecca Levin; Berenbaum, Howard; Heller, Wendy; Miller, Gregory A.

    2010-01-01

    The present study examined the utility of the anhedonic depression scale from the Mood and Anxiety Symptoms Questionnaire (MASQ-AD) as a way to screen for depressive disorders. Using receiver-operator characteristic analysis, the sensitivity and specificity of the full 22-item MASQ-AD scale, as well as the 8 and 14-item subscales, were examined in relation to both current and lifetime DSM-IV depressive disorder diagnoses in two nonpatient samples. As a means of comparison, the sensitivity and specificity of a measure of a relevant personality dimension, neuroticism, was also examined. Results from both samples support the clinical utility of the MASQ-AD scale as a means of screening for depressive disorders. Findings were strongest for the MASQ-AD 8-item subscale and when predicting current depression status. Furthermore, the MASQ-AD 8-item subscale outperformed the neuroticism measure under certain conditions. The overall usefulness of the MASQ-AD scale as a screening device is discussed, as well as possible cutoff scores for use in research. PMID:20822283

  10. Receiver Operating Characteristic (ROC to Determine Cut-Off Points of Biomarkers in Lung Cancer Patients

    Heidi L. Weiss

    2004-01-01

    Full Text Available The role of biomarkers in disease prognosis continues to be an important investigation in many cancer studies. In order for these biomarkers to have practical application in clinical decision making regarding patient treatment and follow-up, it is common to dichotomize patients into those with low vs. high expression levels. In this study, receiver operating characteristic (ROC curves, area under the curve (AUC of the ROC, sensitivity, specificity, as well as likelihood ratios were calculated to determine levels of growth factor biomarkers that best differentiate lung cancer cases versus control subjects. Selected cut-off points for p185erbB-2 and EGFR membrane appear to have good discriminating power to differentiate control tissues versus uninvolved tissues from patients with lung cancer (AUC = 89% and 90%, respectively; while AUC increased to at least 90% for selected cut-off points for p185erbB-2 membrane, EGFR membrane, and FASE when comparing between control versus carcinoma tissues from lung cancer cases. Using data from control subjects compared to patients with lung cancer, we presented a simple and intuitive approach to determine dichotomized levels of biomarkers and validated the value of these biomarkers as surrogate endpoints for cancer outcome.

  11. Receiver operating characteristic analysis of regional cerebral blood flow in Alzheimer's disease

    Zemcov, A.; Barclay, L.L.; Sansone, J.; Metz, C.E.

    1985-01-01

    Receiver operating characteristic (ROC) curves were used to quantitatively assess the ability of individual detectors in a 32-detector 133 Xe inhalation system to discriminate between two populations over the range of regional cerebral blood flow (rCBF) values. These populations were clinically evaluated as normal (age 63.1 +/- 13.1, n = 23) and presumed Alzheimer's disease (age 72.7 +/- 7.0, n = 82). Summary statistics showed that for homologous detectors the average value of blood flow in the normal group was greater than the flow value in the group of subjects with Alzheimer's disease. Conclusions drawn from single values of flow or mean hemispheric flow can lead to erroneous conclusions about hemisphere asymmetries. However, the dynamic relationship between the correct identifications (true positives) compared with incorrect identifications (false positives) of Alzheimer's disease at each detector varies over the range of blood flow values, and quantitative characterization of this relationship in terms of an ROC curve provides more insight into the structure of the data. Detectors approximating the speech, auditory and association cortex were most effective in discriminating between groups. Frontal detectors were marginally useful diagnostically

  12. Operating characteristics of a 0.87 kW-hr flywheel energy storage module

    Loewenthal, S. H.; Scibbe, H. W.; Parker, R. D.; Zaretsky, E. V.

    1985-01-01

    Discussion is given of the design and loss characteristics of 0.87 kW-hr (peak) flywheel energy storage module suitable for aerospace and automotive applications. The maraging steel flywheel rotor, a 46-cm- (18-in-) diameter, 58-kg (128-lb) tapered disk, delivers 0.65 kW-hr of usable energy between operating speeds of 10,000 and 20,000 rpm. The rotor is supported by 20- and 25-mm bore diameter, deep-groove ball bearings, lubricated by a self-replenishing wick type lubrication system. To reduce aerodynamic losses, the rotor housing was evacuated to vacuum levels from 40 to 200 millitorr. Dynamic rotor instabilities uncovered during testing necessitated the use of an elastometric-bearing damper to limit shaft excursions. Spindown losses from bearing, seal, and aerodynamic drag at 50 millitorr typically ranged from 64 to 193 W at 10,000 and 20,000 rpm, respectively. Discharge efficiency of the flywheel system exceeded 96 percent at torque levels greater than 21 percent of rated torque.

  13. Operational characteristic analysis of conduction cooling HTS SMES for Real Time Digital Simulator based power quality enhancement simulation

    Kim, A.R.; Kim, G.H.; Kim, K.M.; Kim, D.W.; Park, M.; Yu, I.K.; Kim, S.H.; Sim, K.; Sohn, M.H.; Seong, K.C.

    2010-01-01

    This paper analyzes the operational characteristics of conduction cooling Superconducting Magnetic Energy Storage (SMES) through a real hardware based simulation. To analyze the operational characteristics, the authors manufactured a small-scale toroidal-type SMES and implemented a Real Time Digital Simulator (RTDS) based power quality enhancement simulation. The method can consider not only electrical characteristics such as inductance and current but also temperature characteristic by using the real SMES system. In order to prove the effectiveness of the proposed method, a voltage sag compensation simulation has been implemented using the RTDS connected with the High Temperature Superconducting (HTS) model coil and DC/DC converter system, and the simulation results are discussed in detail.

  14. Operational characteristics analysis of a 8 mH class HTS DC reactor for an LCC type HVDC system

    Kim, S. K.; Go, B. S.; Dinh, M. C.; Park, M.; Yu, I. K.; Kim, J. H.

    2015-01-01

    Many kinds of high temperature superconducting (HTS) devices are being developed due to its several advantages. In particular, the advantages of HTS devices are maximized under the DC condition. A line commutated converter (LCC) type high voltage direct current (HVDC) transmission system requires large capacity of DC reactors to protect the converters from faults. However, conventional DC reactor made of copper causes a lot of electrical losses. Thus, it is being attempted to apply the HTS DC reactor to an HVDC transmission system. The authors have developed a 8 mH class HTS DC reactor and a model-sized LCC type HVDC system. The HTS DC reactor was operated to analyze its operational characteristics in connection with the HVDC system. The voltage at both ends of the HTS DC reactor was measured to investigate the stability of the reactor. The voltages and currents at the AC and DC side of the system were measured to confirm the influence of the HTS DC reactor on the system. Two 5 mH copper DC reactors were connected to the HVDC system and investigated to compare the operational characteristics. In this paper, the operational characteristics of the HVDC system with the HTS DC reactor according to firing angle are described. The voltage and current characteristics of the system according to the types of DC reactors and harmonic characteristics are analyzed. Through the results, the applicability of an HTS DC reactor in an HVDC system is confirmed

  15. Operational characteristics analysis of a 8 mH class HTS DC reactor for an LCC type HVDC system

    Kim, S. K.; Go, B. S.; Dinh, M. C.; Park, M.; Yu, I. K. [Changwon National University, Changwon (Korea, Republic of); Kim, J. H. [Daejeon University, Daejeon (Korea, Republic of)

    2015-03-15

    Many kinds of high temperature superconducting (HTS) devices are being developed due to its several advantages. In particular, the advantages of HTS devices are maximized under the DC condition. A line commutated converter (LCC) type high voltage direct current (HVDC) transmission system requires large capacity of DC reactors to protect the converters from faults. However, conventional DC reactor made of copper causes a lot of electrical losses. Thus, it is being attempted to apply the HTS DC reactor to an HVDC transmission system. The authors have developed a 8 mH class HTS DC reactor and a model-sized LCC type HVDC system. The HTS DC reactor was operated to analyze its operational characteristics in connection with the HVDC system. The voltage at both ends of the HTS DC reactor was measured to investigate the stability of the reactor. The voltages and currents at the AC and DC side of the system were measured to confirm the influence of the HTS DC reactor on the system. Two 5 mH copper DC reactors were connected to the HVDC system and investigated to compare the operational characteristics. In this paper, the operational characteristics of the HVDC system with the HTS DC reactor according to firing angle are described. The voltage and current characteristics of the system according to the types of DC reactors and harmonic characteristics are analyzed. Through the results, the applicability of an HTS DC reactor in an HVDC system is confirmed.

  16. Research on characteristics of communication content of operation crew in digital main control room of nuclear power plant

    Zhang Li; Ye Haifeng; Qing Tao; Li Pengcheng

    2015-01-01

    Communication content, communication mode and timeliness of communication are the main three factors that influence the effectiveness of the communication between team members. Based on the work domain analysis to execution of state-oriented procedures (SOP), the assumptions for operation crews' characteristics of the communication content in executing SOP were proposed, which supposed that the power plant status and parameters, power plant system functions and equipment, and SOP as well were the main communication contents. On a full-scope simulator of nuclear power plant, three operation crews performed experiments simulating accident scenarios. The results show that the assumptions of characteristics of the communication content are valid. (authors)

  17. Characteristics of ion spectrum in a low energy nitrogen operated plasma focus: application to the metallic substrates thermal treatment

    Kelly, H.; Lepone, A.; Marquez, A.

    1998-01-01

    Full text: This work presents the nitrogen ion spectrum characteristics in a Plasma Focus device, determined using a Thomson spectrometer and a Faraday cup, operated in the secondary electron collective mode. It is also discussed the thermal treatment and the re coating induce by ions incident on a metallic surface (AISI 304 steel) placed in front of the coaxial gun, when the device is operated with a Ti implant at the end of the central electrode

  18. Receiver operating characteristic analysis for the detection of simulated microcalcifications on mammograms using hardcopy images

    Lai, C J; Shaw, Chris C; Whitman, Gary J; Yang, Wei T; Dempsey, Peter J; Nguyen, Victoria; Ice, Mary F

    2006-01-01

    The aim of this study was to compare mammography systems based on three different detectors-a conventional screen-film (SF) combination, an a-Si/CsI flat-panel (FP)-based detector, and a charge-coupled device (CCD)-based x-ray phosphor-based detector-for their performance in detecting simulated microcalcifications (MCs). 112-150 μm calcium carbonate grains were used to simulate MCs and were overlapped with a slab phantom of simulated 50% adipose/50% glandular breast tissue-equivalent material referred to as the uniform background. For the tissue structure background, 200-250 μm calcium carbonate grains were used and overlapped with an anthropomorphic breast phantom. All MC phantom images were acquired with and without magnification (1.8X). The hardcopy images were reviewed by five mammographers. A five-point confidence level rating was used to score each detection task. Receiver operating characteristic (ROC) analysis was performed, and the areas under the ROC curves (A z s) were used to compare the performances of the three mammography systems under various conditions. The results showed that, with a uniform background and contact images, the FP-based system performed significantly better than the SF and the CCD-based systems. For magnified images with a uniform background, the SF and the FP-based systems performed equally well and significantly better than the CCD-based system. With tissue structure background and contact images, the SF system performed significantly better than the FP and the CCD-based systems. With magnified images and a tissue structure background, the SF and the CCD-based systems performed equally well and significantly better than the FP-based system. In the detection of MCs in the fibroglandular and the heterogeneously dense regions, no significant differences were found except that the SF system performed significantly better than the CCD-based system in the fibroglandular regions for the contact images

  19. The ROC Toolbox: A toolbox for analyzing receiver-operating characteristics derived from confidence ratings.

    Koen, Joshua D; Barrett, Frederick S; Harlow, Iain M; Yonelinas, Andrew P

    2017-08-01

    Signal-detection theory, and the analysis of receiver-operating characteristics (ROCs), has played a critical role in the development of theories of episodic memory and perception. The purpose of the current paper is to present the ROC Toolbox. This toolbox is a set of functions written in the Matlab programming language that can be used to fit various common signal detection models to ROC data obtained from confidence rating experiments. The goals for developing the ROC Toolbox were to create a tool (1) that is easy to use and easy for researchers to implement with their own data, (2) that can flexibly define models based on varying study parameters, such as the number of response options (e.g., confidence ratings) and experimental conditions, and (3) that provides optimal routines (e.g., Maximum Likelihood estimation) to obtain parameter estimates and numerous goodness-of-fit measures.The ROC toolbox allows for various different confidence scales and currently includes the models commonly used in recognition memory and perception: (1) the unequal variance signal detection (UVSD) model, (2) the dual process signal detection (DPSD) model, and (3) the mixture signal detection (MSD) model. For each model fit to a given data set the ROC toolbox plots summary information about the best fitting model parameters and various goodness-of-fit measures. Here, we present an overview of the ROC Toolbox, illustrate how it can be used to input and analyse real data, and finish with a brief discussion on features that can be added to the toolbox.

  20. Bayesian receiver operating characteristic estimation of multiple tests for diagnosis of bovine tuberculosis in Chadian cattle.

    Borna Müller

    Full Text Available BACKGROUND: Bovine tuberculosis (BTB today primarily affects developing countries. In Africa, the disease is present essentially on the whole continent; however, little accurate information on its distribution and prevalence is available. Also, attempts to evaluate diagnostic tests for BTB in naturally infected cattle are scarce and mostly complicated by the absence of knowledge of the true disease status of the tested animals. However, diagnostic test evaluation in a given setting is a prerequisite for the implementation of local surveillance schemes and control measures. METHODOLOGY/PRINCIPAL FINDINGS: We subjected a slaughterhouse population of 954 Chadian cattle to single intra-dermal comparative cervical tuberculin (SICCT testing and two recently developed fluorescence polarization assays (FPA. Using a Bayesian modeling approach we computed the receiver operating characteristic (ROC curve of each diagnostic test, the true disease prevalence in the sampled population and the disease status of all sampled animals in the absence of knowledge of the true disease status of the sampled animals. In our Chadian setting, SICCT performed better if the cut-off for positive test interpretation was lowered from >4 mm (OIE standard cut-off to >2 mm. Using this cut-off, SICCT showed a sensitivity and specificity of 66% and 89%, respectively. Both FPA tests showed sensitivities below 50% but specificities above 90%. The true disease prevalence was estimated at 8%. Altogether, 11% of the sampled animals showed gross visible tuberculous lesions. However, modeling of the BTB disease status of the sampled animals indicated that 72% of the suspected tuberculosis lesions detected during standard meat inspections were due to other pathogens than Mycobacterium bovis. CONCLUSIONS/SIGNIFICANCE: Our results have important implications for BTB diagnosis in a high incidence sub-Saharan African setting and demonstrate the practicability of our Bayesian approach for

  1. ROC-ing along: Evaluation and interpretation of receiver operating characteristic curves.

    Carter, Jane V; Pan, Jianmin; Rai, Shesh N; Galandiuk, Susan

    2016-06-01

    It is vital for clinicians to understand and interpret correctly medical statistics as used in clinical studies. In this review, we address current issues and focus on delivering a simple, yet comprehensive, explanation of common research methodology involving receiver operating characteristic (ROC) curves. ROC curves are used most commonly in medicine as a means of evaluating diagnostic tests. Sample data from a plasma test for the diagnosis of colorectal cancer were used to generate a prediction model. These are actual, unpublished data that have been used to describe the calculation of sensitivity, specificity, positive predictive and negative predictive values, and accuracy. The ROC curves were generated to determine the accuracy of this plasma test. These curves are generated by plotting the sensitivity (true-positive rate) on the y axis and 1 - specificity (false-positive rate) on the x axis. Curves that approach closest to the coordinate (x = 0, y = 1) are more highly predictive, whereas ROC curves that lie close to the line of equality indicate that the result is no better than that obtained by chance. The optimum sensitivity and specificity can be determined from the graph as the point where the minimum distance line crosses the ROC curve. This point corresponds to the Youden index (J), a function of sensitivity and specificity used commonly to rate diagnostic tests. The area under the curve is used to quantify the overall ability of a test to discriminate between 2 outcomes. By following these simple guidelines, interpretation of ROC curves will be less difficult and they can then be interpreted more reliably when writing, reviewing, or analyzing scientific papers. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Analysis characteristics determination of electrohydraulic control system operation to reduce the operation time of a powered roof support

    Szurgacz, Dawid

    2018-01-01

    The article discusses basic functions of a powered roof support in a longwall unit. The support function is to provide safety by protecting mine workings against uncontrolled falling of rocks. The subject of the research includes the measures to shorten the time of roof support shifting. The roof support is adapted to transfer, in hazard conditions of rock mass tremors, dynamic loads caused by mining exploitation. The article presents preliminary research results on the time reduction of the unit advance to increase the extraction process and thus reduce operating costs. Conducted stand tests showed the ability to increase the flow for 3/2-way valve cartridges. The level of fluid flowing through the cartridges is adequate to control individual actuators.

  3. Receiver-operating characteristic curves for somatic cell scores and California mastitis test in Valle del Be lice dairy sheep

    Riggio, V.; Pesce, L.L.; Morreale, S.; Portolano, B.

    2013-01-01

    Using receiver-operating characteristic (ROC) curve methodology this study was designed to assess the diagnostic effectiveness of somatic cell count (SCC) and the California mastitis test (CMT) in Valle del Belice sheep, and to propose and evaluate threshold values for those tests that would

  4. Screening for Depressive Disorders Using the Mood and Anxiety Symptoms Questionnaire Anhedonic Depression Scale: A Receiver-Operating Characteristic Analysis

    Bredemeier, Keith; Spielberg, Jeffery M.; Silton, Rebecca Levin; Berenbaum, Howard; Heller, Wendy; Miller, Gregory A.

    2010-01-01

    The present study examined the utility of the anhedonic depression scale from the Mood and Anxiety Symptoms Questionnaire (MASQ-AD scale) as a way to screen for depressive disorders. Using receiver-operating characteristic analysis, we examined the sensitivity and specificity of the full 22-item MASQ-AD scale, as well as the 8- and 14-item…

  5. Main components and characteristics of landslide early warning systems operational worldwide

    Piciullo, Luca; Cepeda, José

    2017-04-01

    During the last decades the number of victims and economic losses due to natural hazards are dramatically increased worldwide. The reason can be mainly ascribed to climate changes and urbanization in areas exposed at high level of risk. Among the many mitigation measures available for reducing the risk to life related to natural hazards, early warning systems certainly constitute a significant cost-effective option available to the authorities in charge of risk management and governance. The aim is to help and protect populations exposed to natural hazards, reducing fatalities when major events occur. Landslide is one of the natural hazards addressed by early warning systems. Landslide early warning systems (LEWSs) are mainly composed by the following four components: set-up, correlation laws, decisional algorithm and warning management. Within this framework, the set-up includes all the preliminary actions and choices necessary for designing a LEWS, such as: the area covered by the system, the types of landslides and the monitoring instruments. The monitoring phase provides a series of important information on different variables, considered as triggering factors for landslides, in order to define correlation laws and thresholds. Then, a decisional algorithm is necessary for defining the: number of warning levels to be employed in the system, decision making procedures, and everything else system managers may need for issuing warnings in different warning zones. Finally the warning management is composed by: monitoring and warning strategy; communication strategy; emergency plan and, everything connected to the social sphere. Among LEWSs operational worldwide, two categories can be defined as a function of the scale of analysis: "local" and "territorial" systems. The scale of analysis influences several actions and aspects connected to the design and employment of the system, such as: the actors involved, the monitoring systems, type of landslide phenomena

  6. Impact characteristics for high-pressure large-flow water-based emulsion pilot operated check valve reverse opening

    Liu, Lei; Huang, Chuanhui; Yu, Ping; Zhang, Lei

    2017-10-01

    To improve the dynamic characteristics and cavitation characteristics of large-flow pilot operated check valve, consider the pilot poppet as the research object, analyses working principle and design three different kinds of pilot poppets. The vibration characteristics and impact characteristics are analyzed. The simulation model is established through flow field simulation software. The cavitation characteristics of large-flow pilot operated check valve are studied and discussed. On this basis, high-pressure large-flow impact experimental system is used for impact experiment, and the cavitation index is discussed. Then optimal structure is obtained. Simulation results indicate that the increase of pilot poppet half cone angle can effectively reduce the cavitation area, reducing the generation of cavitation. Experimental results show that the pressure impact is not decreasing with increasing of pilot poppet half cone angle in process of unloading, but the unloading capacity, response speed and pilot poppet half cone angle are positively correlated. The impact characteristics of 60° pilot poppet, and its cavitation index is lesser, which indicates 60° pilot poppet is the optimal structure, with the theory results are basically identical.

  7. IR radiation characteristics of rocket exhaust plumes under varying motor operating conditions

    Qinglin NIU

    2017-06-01

    Full Text Available The infrared (IR irradiance signature from rocket motor exhaust plumes is closely related to motor type, propellant composition, burn time, rocket geometry, chamber parameters and flight conditions. In this paper, an infrared signature analysis tool (IRSAT was developed to understand the spectral characteristics of exhaust plumes in detail. Through a finite volume technique, flow field properties were obtained through the solution of axisymmetric Navier-Stokes equations with the Reynolds-averaged approach. A refined 13-species, 30-reaction chemistry scheme was used for combustion effects and a k-ε-Rt turbulence model for entrainment effects. Using flowfield properties as input data, the spectrum was integrated with a line of sight (LOS method based on a single line group (SLG model with Curtis-Godson approximation. The model correctly predicted spectral distribution in the wavelengths of 1.50–5.50 μm and had good agreement for its location with imaging spectrometer data. The IRSAT was then applied to discuss the effects of three operating conditions on IR signatures: (a afterburning; (b chamber pressure from ignition to cutoff; and (c minor changes in the ratio of hydroxyl-terminated polybutadiene (HTPB binder to ammonium perchlorate (AP oxidizer in propellant. Results show that afterburning effects can increase the size and shape of radiance images with enhancement of radiation intensity up to 40%. Also, the total IR irradiance in different bands can be characterized by a non-dimensional chamber pressure trace in which the maximum discrepancy is less than 13% during ignition and engine cutoff. An increase of chamber pressure can lead to more distinct diamonds, whose distance intervals are extended, and the position of the first diamond moving backwards. In addition, an increase in HTPB/AP causes a significant jump in spectral intensity. The incremental rates of radiance intensity integrated in each band are linear with the increase of HTPB

  8. Drive Control Scheme of Electric Power Assisted Wheelchair Based on Neural Network Learning of Human Wheelchair Operation Characteristics

    Tanohata, Naoki; Seki, Hirokazu

    This paper describes a novel drive control scheme of electric power assisted wheelchairs based on neural network learning of human wheelchair operation characteristics. “Electric power assisted wheelchair” which enhances the drive force of the operator by employing electric motors is expected to be widely used as a mobility support system for elderly and disabled people. However, some handicapped people with paralysis of the muscles of one side of the body cannot maneuver the wheelchair as desired because of the difference in the right and left input force. Therefore, this study proposes a neural network learning system of such human wheelchair operation characteristics and a drive control scheme with variable distribution and assistance ratios. Some driving experiments will be performed to confirm the effectiveness of the proposed control system.

  9. Operating characteristics of a prototype high energy gamma-ray telescope

    Jenkins, T.L.; Frye, G.M.; Hall, C.J.; Owens, A.; Pendleton, G.N.; Carter, J.N.; Ramsden, D.; Agrinier, B.; Bonfand, E.; Refloch, A.; Tabary, A.

    1985-08-01

    We have operated a prototype coded aperture telescope in a tagged photon beam ranging in energy from 23 to 123 MeV. The purpose of the experiment was to demonstrate the feasibility of operating a coded aperture mask telescope in this energy region. This paper reports some preliminary results and conclusions drawn from some of the data resulting from this experiment

  10. CFD investigating the effects of different operating conditions on the performance and the characteristics of a high-temperature PEMFC

    Su, A.; Ferng, Y.M.; Shih, J.C.

    2010-01-01

    The effects of different operating conditions on the performance and the characteristics of a high-temperature proton exchange membrane fuel cell (PEMFC) are investigated using a three-dimensional (3-D) computational fluid dynamics (CFD) fuel-cell model. This model consists of the thermal-hydraulic equations and the electrochemical equations. Different operating conditions studied in this paper include the inlet gas temperature, system pressure, and inlet gas flow rate, respectively. Corresponding experiments are also carried out to assess the accuracy of this CFD model. Under the different operating conditions, the PEMFC performance curves predicted by the model correspond well with the experimentally measured ones. The performance of PEMFC is improved as the increase in the inlet temperature, system pressure or flow rate, which is precisely captured by the CFD fuel cell model. In addition, the concentration polarization caused by the insufficient supply of fuel gas can be also simulated as the high-temperature PEMFC is operated at the higher current density. Based on the calculation results, the localized thermal-hydraulic characteristics within a PEMFC can be reasonably captured. These characteristics include the fuel gas distribution, temperature variation, liquid water saturation distribution, and membrane conductivity, etc.

  11. Fixation of operating point and measurement of turn on characteristics of IGBT F4-75R06W1E3

    Haseena, A.; Subhash Joshi T., G.; George, Saly

    2018-05-01

    For the proficient operation of the Power electronic circuit, signal level performance of power electronic devices are very important. For getting good signal level characteristics, fixing operating point is very critical. Device deviates from the typical characteristics given in the datasheet due to the presence of stray components in the circuit lay out. Fixation of operating point of typical silicon IGBT and its turn on characteristics is discussed in this paper.

  12. The characteristics of activities of the operator of a management system by the line for release of foodstuff

    Al-Hetari H.M. Abdulaziz

    2016-01-01

    Full Text Available The article presents the analysis of the main stages of professional activity of the operator of a management system by a production line of food products. Studied the question of the serious consequences of human error as the cause of the marriage in the manufacture of food products on automated lines. The nature of the error automated systems operators as a result of the deterioration of psychophysical state of the working person. The importance of modeling the signal generating emergency alarm, can significantly reduce the probability of release of potentially dangerous products. The optimality of the psychophysical state of the control system operator line of food production is highlighted as one of the main criteria for the rational organization of work. The problem of assessing changes in the human condition is also studied, participating in professional activities. The classification of types of functional states control over employee -depending on its purpose. Special attention in work is paid to an example of change of a psychophysical state, expressed in exhaustion of the worker of production. It gives a detailed description of the external signs of exhaustion in the comparative analysis of manual and mental work. The article shows the main tariff and qualification characteristics of activities of operators of lines in production of food products depending on their categories are specified. Describes a group of workers, depending on the operator's activity, indicating the brief description of each group. Based on the analysis of tariff and qualifying characteristics of lines of the operators in the production of food products of different categories, it shows that the range of qualifying categories covers almost al l groups of workers with the exception of the head of the operator. Highlight the desired differentiated approach to the assessment of psychophysiological state operators.

  13. Design parameters and operating characteristics of animal waste anaerobic digestion systems - swine and poultry

    Hill, D T

    1983-01-01

    The development and validation of a comprehensive dynamic simulation model of the anaerobic fermentation of animal waste have been described by Hill. This model has proved to be highly accurate, both qualitatively and quantitatively, in predicting the steady-state methane productivity of conventional fermentation plants and in simulating the transient-state response of semi-batch fed digesters. Simulation studies using this model have been performed and results have been used to develop design recommendations for steady-state operations. These simulation studies have also produced a start-up procedure that will ensure successful initial operation of the digestion system and, more importantly, have allowed determination of the operational techniques that will provide recovery from failure due to organic overloading or excessively short detention time. This paper describes the results of these studies for swine and poultry (caged layer) waste and presents the design recommendations and operating techniques developed from the simulations. (Refs. 11).

  14. Machine characteristics, system arrangement, driver and operation effects on surge of dynamic compressor in oil and gas plants

    Almasi, Amin

    2012-12-15

    Working in the surge area will result in an unstable compressor operation, exposing the dynamic compressor (centrifugal compressor or axial compressor) to destructive stress, high vibration and other damaging effects. The destructive power of the surge is enormous, ranging from changes in clearances, which result in a penalty in the compressor efficiency, to destruction of parts leading to bearing, rotor or seal replacements. The effects of compressor characteristics, driver type, compressor accessories, vent valve, check valve, trip delay and operation details on surge events and anti-surge system designs are studied. A case study is also discussed. (orig.)

  15. Operational characteristics of a 100-mA, 2-MeV radio-frequency quadrupole

    Johnson, K.F.; Cottingame, W.B.; Bolme, G.O.; Fortgang, C.M.; Ingalls, W.B.; Marquardt, J.; Rusthoi, D.P.; Sander, O.R.; Smith, M.; Worth, G.T.

    1993-01-01

    A 100-mA, 2.07-MeV Radio-Frequency Quadrupole (RFQ III) has been commissioned and operated routinely on the Accelerator Test Stand (ATS) [1] at Los Alamos National Laboratory. To characterize the RFQ output beam dynamics, measurements were made of the beam transmission and of the transverse and longitudinal phase-space distributions. Data were taken for different RFQ III operating conditions and compared to simulations

  16. Approach to evaluation and prediction of lifetime characteristics of NPP valve on the basis of operation data

    Emelyanov, V.; Kamyshnikov, O.; Dovgalyuk, V.; Plying, B.

    1994-01-01

    The report contains brief description of the main activity stages for testing, evaluation and prediction of reliability factors (including characteristics and factors of longevity) for NPP operating equipment. Valves equipped with electric drive that are installed in level control system of steam generator in WWER-1000 reactor are taken as an example. Main emphasis is made on classification of failures which had taken place during operation, on detection of prevailing mechanisms of ageing and on assessment of operation factors of reliability and methods of their testing, assessment and prediction. Principles of product ageing parameters selection are briefly described as well as mathematic methods used for quantitative assessment of products reliability factors according to its operation data. The report includes considerations on procedure of operating evaluation, testing and prediction of complex unique equipment based on testing of state vectors path, probabilities of defining parameters to be tested characterizing operability of set components within the assumed boundaries written in design and operation documentation are components of the vectors mentioned above. 9 refs, 4 figs

  17. Dynamic Performance Characteristics of a Curved Slider Bearing Operating with Ferrofluids

    Udaya P. Singh

    2012-01-01

    Full Text Available In the present theoretical investigation, the effect of ferrofluid on the dynamic characteristics of curved slider bearings is presented using Shliomis model which accounts for the rotation of magnetic particles, their magnetic moments, and the volume concentration in the fluid. The modified Reynolds equation for the dynamic state of the bearing is obtained. The results of dynamic stiffness and damping characteristics are presented. It is observed that the effect of rotation of magnetic particles improves the stiffness and damping capacities of the bearings.

  18. Research on the operation characteristics of a free-piston linear generator: Numerical model and experimental results

    Guo, Chendong; Feng, Huihua; Jia, Boru; Zuo, Zhengxing; Guo, Yuyao; Roskilly, Tony

    2017-01-01

    Highlights: • The operation process of free-piston linear generator is investigated. • The larger the motor force at the starting process, the fewer circulations of the piston reciprocating to meet ignition condition. • The “gradually switching strategy” is the best strategy in the intermediate process. • During the generating process, engines indicated power is 2.9 kW with an efficiency of 37.3% under medium load. - Abstract: Free piston linear generator (FPLG) shows unique operation characteristics due to the elimination of crankshaft and connecting rod mechanism. This paper investigates its operation characteristics during each operating process based on the simulation and experiment results. During the starting process, the larger motor force during the starting process, the fewer times of reciprocating pistons which meet the condition of ignition. When the motor force reached 300 N, the prototype could adopt one-stroke starting strategy. During the intermediate process, it was found that the “gradually switching strategy” could help to achieve a smoother operation during the intermediate process. And the values of the operation parameters after the intermediate process were lower than those before the intermediate process. During the generating process, cycle-to-cycle variations were observed for piston TDC and in-cylinder gas pressure from the experimental results. According to the experimental results of the FPLG during the generating process, the calculated engine indicated power is 2.9 kW, and the corresponding indicated thermal efficiency is 37.3%. Additionally, based on the comparison of the FPLG performance, it is found that the parameters of the FPLG during the generating process are smaller than those when it was operated during the second stage of the starting process, while much higher than those during the first stage of the starting process.

  19. Operation Characteristics Optimization of Low Power Three-Phase Asynchronous Motors

    VLAD, I.

    2014-02-01

    Full Text Available Most published papers on low power asynchronous motors were aimed to achieve better operational performances in different operating conditions. The optimal design of the general-purpose motors requires searching and selecting an electric machine to meet minimum operating costs criterion and certain customer imposed restrictive conditions. In this paper, there are many significant simulations providing qualitative and quantitative information on reducing active and reactive energy losses in motors, and on parameters and constructive solution. The optimization study applied the minimal operating costs criterion, and it took into account the starting restrictive conditions. Thirteen variables regarding electromagnetic stresses and main constructive dimensions were considered. The operating costs of the optimized motor decreased with 25.6%, as compared to the existing solution. This paper can be a practical and theoretical support for the development and implementation of modern design methods, based on theoretical and experimental study of stationary and transient processes in low power motors, to increase efficiency and power factor.

  20. Job task characteristics of Australian emergency services volunteers during search and rescue operations.

    Silk, Aaron; Lenton, Gavin; Savage, Robbie; Aisbett, Brad

    2018-02-01

    Search and rescue operations are necessary in locating, assisting and recovering individuals lost or in distress. In Australia, land-based search and rescue roles require a range of physically demanding tasks undertaken in dynamic and challenging environments. The aim of the current research was to identify and characterise the physically demanding tasks inherent to search and rescue operation personnel within Australia. These aims were met through a subjective job task analysis approach. In total, 11 criterion tasks were identified by personnel. These tasks were the most physically demanding, frequently occurring and operationally important tasks to these specialist roles. Muscular strength was the dominant fitness component for 7 of the 11 tasks. In addition to the discrete criterion tasks, an operational scenario was established. With the tasks and operational scenario identified, objective task analysis procedures can be undertaken so that practitioners can implement evidence-based strategies, such as physical selection procedures and task-based physical training programs, commensurate with the physical demands of search and rescue job roles. Practitioner Summary: The identification of physically demanding tasks amongst specialist emergency service roles predicates health and safety strategies which can be incorporated into organisations. Knowledge of physical task parameters allows employers to mitigate injury risk through the implementation of strategies modelled on the precise physical demands of the role.

  1. Global characteristics of an ATON stationary plasma thruster operating with krypton and xenon

    Bugrova, A.I.; Lipatov, A.S.; Solomatina, L.V.; Morozov, A.I.

    2002-01-01

    Paper contains the experimental results of operation of the ATON plasma thruster operating with krypton and xenon. It is shown that consumption of a working gas for consumption of a working gas the krypton base thrust is higher in contrast to xenon base one at lower efficiency. In case of krypton use one obtained the efficiency constituting ∼ 60% at specific pulse reaching 3000 s. Jet divergence in case of krypton use is ∼ ± 22 deg in contrast to ∼ ± 11 deg in case of xenon use [ru

  2. NSSS operating characteristics: experience obtained from Fessenheim nuclear power station start-up

    Gouffon, A.; Wilmart, Y.

    1978-01-01

    The two 900 MWe units of the Fessenheim Nuclear Power Plant are the first of a series of 26 installations equipped with Framatome 3-loop PWR-type NSSS systems which are scheduled to enter into service in France by 1982. The tests carried out at Fessenheim represented the first of the series, and thus it was important to provide the most complete tests possible. We shall examine here only the part of the operating tests which made it possible to demonstrate the correct behavior of these reactors under transient conditions and the adaptation of regulation systems required to meet the needs of a modern operation

  3. Real time estimation of photovoltaic modules characteristics and its application to maximum power point operation

    Garrigos, Ausias; Blanes, Jose M.; Carrasco, Jose A. [Area de Tecnologia Electronica, Universidad Miguel Hernandez de Elche, Avda. de la Universidad s/n, 03202 Elche, Alicante (Spain); Ejea, Juan B. [Departamento de Ingenieria Electronica, Universidad de Valencia, Avda. Dr Moliner 50, 46100 Valencia, Valencia (Spain)

    2007-05-15

    In this paper, an approximate curve fitting method for photovoltaic modules is presented. The operation is based on solving a simple solar cell electrical model by a microcontroller in real time. Only four voltage and current coordinates are needed to obtain the solar module parameters and set its operation at maximum power in any conditions of illumination and temperature. Despite its simplicity, this method is suitable for low cost real time applications, as control loop reference generator in photovoltaic maximum power point circuits. The theory that supports the estimator together with simulations and experimental results are presented. (author)

  4. Evaluation of the behavioral characteristics of the mdx mouse model of duchenne muscular dystrophy through operant conditioning procedures.

    Lewon, Matthew; Peters, Christina M; Van Ry, Pam M; Burkin, Dean J; Hunter, Kenneth W; Hayes, Linda J

    2017-09-01

    The mdx mouse is an important nonhuman model for Duchenne muscular dystrophy (DMD) research. Characterizing the behavioral traits of the strain relative to congenic wild-type (WT) mice may enhance our understanding of the cognitive deficits observed in some humans with DMD and contribute to treatment development and evaluation. In this paper we report the results of a number of experiments comparing the behavior of mdx to WT mice in operant conditioning procedures designed to assess learning and memory. We found that mdx outperformed WT in all learning and memory tasks involving food reinforcement, and this appeared to be related to the differential effects of the food deprivation motivating operation on mdx mice. Conversely, WT outperformed mdx in an escape/avoidance learning task. These results suggest motivational differences between the strains and demonstrate the potential utility of operant conditioning procedures in the assessment of the behavioral characteristics of the mdx mouse. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. To selecting the characteristics of saturated steam direct cycle NPPs for operation under variable loads

    Khrustalev, V.A.; Demidov, O.I.

    1986-01-01

    Problems for operating process optimization of NPPs with RBMK type reactors under load swings in the power system is considered. Determination technique for optimal values of such parameters as initial steam pressure and fuel enrichment for NPP different load factors is developed. Optimization of these parameters gives a 150000 rouble saving of annual expenditures per each 3200 MW of reactor heat output

  6. A summary of design, policies and operational characteristics for shared bicycle/bus lanes.

    2012-07-01

    This report contains the results of an investigation of the design and operation of shared bicycle/bus lanes in municipalities in the United States and other countries. These lanes are designated for use by public transit buses, bicycles, and usually...

  7. Detector evaluation for improved situational awareness: Receiver operator characteristic curve based

    Wuijckhuijse, A.L. van; Nieuwenhuizen, M.S.

    2016-01-01

    In military and civilian operations good situational awareness is a prerequisite to make proper decisions. The situational awareness is among others based upon intelligence, threat analysis and detection, altogether element of the so-called DIM (detection, identification, monitoring) system. In case

  8. Prediction of Operating Characteristics of Electrotechnical Devices using Artificial Neural Networks

    PASCA Alexandra

    2014-05-01

    Full Text Available The paper purpose is to emphasize the possibilities and the advantages to use the artificial intelligence techniques for operating mode prediction of electrotechnical devices. The considered application consists of the analysis of behavior of an inductive proximity sensor at variation of design parameters.

  9. Operational characteristics in the three-phase transformer-type SFCL with neutral line based on sequential reclosing process

    Cho, Y.S.; Choi, H.S.; Jung, B.I.

    2011-01-01

    The three-phase transformer-type SFCL with a neutral line can control the current limiting rates according to the turn's ratio between primary and secondary windings. The transformer-type SFCL with a neutral line can reliably conduct the fault current limiting operation according to the reclosing operation duty and fault types. The superconducting elements recovered their superconducting state within the opening cycle of the circuit breaker according to the reclosing operation duty. It is expected to improve the transient stability and supply reliability of the power network. In a transformer-type superconducting fault current limiter (SFCL) with a neutral line, which is connected between the superconducting elements and secondary windings, we verified that the SFCL has excellent characteristics that induce the perfect simultaneous quench of the superconducting elements in the previous study. The application of the SFCL to the power networks requires its coordination with the reclosing operation duty, which protects a circuit. In this study, the fault current limiting and recovery characteristics of superconducting elements in the three-phase transformer-type SFCL with the neutral line were analyzed. The limiting rate of the fault current in the transformer-type SFCL could increased by an iron core, which allows quenching of the superconducting elements in a sound phase as well as in a faulted phase. In addition, the simultaneous quench led to uniform burdens on superconducting elements, all of which recovered their superconducting state within an opening cycle of a circuit breaker. Thus, the transformer-type SFCL with the neutral line could reliably conduct the fault current limiting and recovery operations of superconducting elements according to the reclosing operation duty and fault types.

  10. Change in working characteristics of the steam turbine metal with operating time of more than 330000 hours

    Gladshteyn, V. I.; Troitskiy, A. I.

    2017-01-01

    Research of a metal of the stop valve case (SVC) of the K-300-23.5 LMZ turbine (steel grade 15Kh1M1FL), destroyed after operation for 331000 hours, is performed. It's chemical composition and properties are determined as follows: a short-term mechanical tensile stress at 20°C and at elevated temperature, critical temperature, fragility, critical crack opening at elevated temperature, and long-term strength. Furthermore, nature of the microstructure, packing density of carbide particles and their size, and chemical composition of carbide sediment are estimated. A manifestation of metal properties for the main case components by comparison with a forecast of the respective characteristics made for the operating time of 331000 hours is tested. Property-time relationships are built for the forecast using statistical treatment of the test results for the samples cut out from more than 300 parts. Representativeness of the research results is proved: the statistical treatment of their differences are within the range of ±5%. It has been found that, after 150000 hours of operation, only the tensile strength insignificantly depends on the operating time at 20°C, whereas indicators of strength at elevated temperature significantly reduce, depending on the operating time. A brittle-to-ductile transition temperature (BDTT) raises, a critical notch opening changes in a complicated way, a long-term strength reduces. It has been found empirically that the limit of a long-term strength of the SVC metal at 540°C and the operating time of 105 hours is almost 1.6 times less than the required value in the as-delivered state. It is possible to evaluate a service life of the operating valves with the operating time of more than 330000 hours with respect to the long-term strength of the metal taking into account the actual temperature and stress. Guidelines for the control of similar parts are provided.

  11. Reclosing operation characteristics of the flux-coupling type SFCL in a single-line-to ground fault

    Jung, B.I.; Cho, Y.S.; Choi, H.S.; Ha, K.H.; Choi, S.G.; Chul, D.C.; Sung, T.H.

    2011-01-01

    The recloser that is used in distribution systems is a relay system that behaves sequentially to protect power systems from transient and continuous faults. This reclosing operation of the recloser can improve the reliability and stability of the power supply. For cooperation with this recloser, the superconducting fault current limiter (SFCL) must properly perform the reclosing operation. This paper analyzed the reclosing operation characteristics of the three-phase flux-coupling type SFCL in the event of a ground fault. The fault current limiting characteristics according to the changing number of turns of the primary and secondary coils were examined. As the number of turns of the first coil increased, the first maximum fault current decreased. Furthermore, the voltage of the quenched superconducting element also decreased. This means that the power burden of the superconducting element decreases based on the increasing number of turns of the primary coil. The fault current limiting characteristic of the SFCL according to the reclosing time limited the fault current within a 0.5 cycles (8 ms), which is shorter than the closing time of the recloser. In other words, the superconducting element returned to the superconducting state before the second fault and normally performed the fault current limiting operation. If the SFCL did not recover before the recloser reclosing time, the normal current that was flowing in the transmission line after the recovery of the SFCL from the fault would have been limited and would have caused losses. Therefore, the fast recovery time of a SFCL is critical to its cooperation with the protection system.

  12. Reclosing operation characteristics of the flux-coupling type SFCL in a single-line-to ground fault

    Jung, B. I.; Cho, Y. S.; Choi, H. S.; Ha, K. H.; Choi, S. G.; Chul, D. C.; Sung, T. H.

    2011-11-01

    The recloser that is used in distribution systems is a relay system that behaves sequentially to protect power systems from transient and continuous faults. This reclosing operation of the recloser can improve the reliability and stability of the power supply. For cooperation with this recloser, the superconducting fault current limiter (SFCL) must properly perform the reclosing operation. This paper analyzed the reclosing operation characteristics of the three-phase flux-coupling type SFCL in the event of a ground fault. The fault current limiting characteristics according to the changing number of turns of the primary and secondary coils were examined. As the number of turns of the first coil increased, the first maximum fault current decreased. Furthermore, the voltage of the quenched superconducting element also decreased. This means that the power burden of the superconducting element decreases based on the increasing number of turns of the primary coil. The fault current limiting characteristic of the SFCL according to the reclosing time limited the fault current within a 0.5 cycles (8 ms), which is shorter than the closing time of the recloser. In other words, the superconducting element returned to the superconducting state before the second fault and normally performed the fault current limiting operation. If the SFCL did not recover before the recloser reclosing time, the normal current that was flowing in the transmission line after the recovery of the SFCL from the fault would have been limited and would have caused losses. Therefore, the fast recovery time of a SFCL is critical to its cooperation with the protection system.

  13. Characteristics of plasma streams and optimization of operational regimes for magnetoplasma compressor

    Bandura, A.N.; Byrka, O.V.; Garkusha, I.E.; Ladygina, M.S.; Marchenko, A.K.; Petrov, Yu.V.; Solyakov, D.G.; Chebotarev, V.V.; Chuvilo, A.A.

    2011-01-01

    The main objective of these studies is characterization of dense xenon plasma streams generated by magnetoplasma compressor (MPC) in different operational regimes. Optimization of plasma compression in MPC allows increase of the plasma stream pressure up to 22...25 bar, average temperature of electrons of 10...20 eV and plasma stream velocity varied in the range of (2...9)x10 6 cm/s depending on operation regime. Spectroscopy measurements demonstrate that in these conditions most of Xe spectral lines are reabsorbed. In the case of known optical thickness, the real value of electron density can be calculated with accounting self-absorption. Estimations of optical thickness were performed and resulting electron density in focus region was evaluated as 10 18 cm -3 .

  14. Operative and postoperative control of variations in characteristics of physicochemical processes in NPP circuits

    Vilkov, N.Ya.; Krjukov, Yu.V.; Blinov, S.V.; Fedoseev, M.V.

    2002-01-01

    Based on actual data obtained from operative chemical monitoring in operating NPPs, the authors show the use of some probability diagnosis methods in practical applications such as identification of anomalies of the water chemistry condition, specifically, in the following: detecting violation of control limits a priori determined for the water chemistry parameters, using the control card method; construction of detectors for identifying probably (statistically) significant stepwise changes in the current arithmetical mean of the water chemistry parametric values; identifying successive changes in the behavior of robust estimators of the monitored parameters values; construction of robust linear regression prognostic models for dynamic changes in the monitored parameters values; correlation analysis of time series formed from the measured data on the water chemistry connected parameters (which are lumped (concentrated at one control point) and/or distributed along the coolant path). (author)

  15. Aerosol characteristics in the offgas from a pilot-scale sluicing operation

    Ligotke, M.W.; Whyatt, G.A.; Beckette, M.R.

    1995-01-01

    A pilot-scale study was performed to simulate conditions anticipated during sluicing operations to retrieve waste in single-shell Tank 241-C-106 at the US Department of Energy's Hanford Site in southeastern Washington. The objective of the study was to identify and characterize the potential aerosol source term at the inlet of the headspace exhaust ventilation system during sluicing operations. The information is needed to support decisions for components to be used in the full-scale operation. A secondary objective was to qualitatively evaluate the visibility during sluicing. Three simulated sluicing tests were performed in the 336 Building's quarter-scale waste tank facility located at Hanford. Scaling relationships were used to guide modifications to the quarter-scale tank to accommodate tests that simulated tank geometry, sluicing, and ventilation conditions in the full-scale tank. Simulated sluicing fluids were targeted on solid and liquid surfaces during the tests. Test conditions were monitored, and aerosol measurements were made in the offgas ventilation duct. Also during the tests, an in-tank camera was used to monitor visibility

  16. Aerosol characteristics in the offgas from a pilot-scale sluicing operation

    Ligotke, M.W.; Whyatt, G.A.; Beckette, M.R.

    1995-01-01

    A pilot-scale study was performed to simulate conditions anticipated during sluicing operations to retrieve waste in single-shell Tank 241-C-106 at the US Department of Energy`s Hanford Site in southeastern Washington. The objective of the study was to identify and characterize the potential aerosol source term at the inlet of the headspace exhaust ventilation system during sluicing operations. The information is needed to support decisions for components to be used in the full-scale operation. A secondary objective was to qualitatively evaluate the visibility during sluicing. Three simulated sluicing tests were performed in the 336 Building`s quarter-scale waste tank facility located at Hanford. Scaling relationships were used to guide modifications to the quarter-scale tank to accommodate tests that simulated tank geometry, sluicing, and ventilation conditions in the full-scale tank. Simulated sluicing fluids were targeted on solid and liquid surfaces during the tests. Test conditions were monitored, and aerosol measurements were made in the offgas ventilation duct. Also during the tests, an in-tank camera was used to monitor visibility.

  17. Operational characteristics of a high voltage plasma focus device working with deuterium and heavy gas mixture

    Zoita, V.; Presura, R.; Gherendi, F.; Dumitrescu-Zoita, C.; Aliaga, R.

    1992-01-01

    The addition of a few neon percents to the deuterium gas filling of a medium energy plasma focus device (PFD) changes dramatically the radiation characteristics of the discharge as well as the pinch configuration. One exceptional result is the generation of high aspect ratio pinches shown clearly and reproducibly on X-ray pinhole camera images and on schlieren pictures. Another remarkable result is that these pinches which show no macroscopic instabilities copiously produce neutrons and hard X-rays. This confirms an experimental fact previously identified on a lower voltage PFD: the macroscopic instabilities do not play the decisive role in the neutronic performance of medium energy PFD's. (Author)

  18. Topological characteristics of the spectrum of the Schrodinger operator in a magnetic field and in a weak potential

    Lyskova, A.S.

    1986-01-01

    This paper studies the two-dimensional Schrodinger operator H in a periodic magnetic field B(x,y) and in an electric field with periodic potential V(x,y). It is assumed that the functions B(x,y) and V(x,y) are periodic with respect to some lattice in R 2 and that the m agnetic flux through a unit cell is an integral number. The operator H is represented as a direct integral over the two-dimensional torus of the reciprocal lattice of elliptic self-adjoint operators H /sub p1/, /sub p2/ which possess a discrete spectrum lambda /sub j/ (p 1 ,p 2 ), j = 0,1,2.... On the basis of an exactly integrable case - the Schrodinger operator in a constant magnetic field - perturbation theory is used to investigate the typical dispersion laws lambda /sub j/ (p 1 ,p 2 ) and establish their topological characteristics (quantum numbers). A theorem is proved: In the general case, the Schrodinger operator has a coutable number of dispersion laws with arbitrary quantum numbers in no way related to one another or to thflux of the external magnetic field

  19. Self-validated calculation of characteristics of a Francis turbine and the mechanism of the S-shape operational instability

    Zhang, Z; Titzschkau, M

    2012-01-01

    A calculation method has been presented to accurately estimate the characteristics of a Francis turbine. Both the shock loss at the impeller inlet and the swirling flow loss at the Impeller exit have been confirmed to dominantly influence the turbine characteristics and particularly the hydraulic efficiency. Both together totally govern the through flow of water through the impeller being at the rest. Calculations have been performed for the flow rate, the shaft torque and the hydraulic efficiency and compared with the available measurements on a model turbine. Excellent agreements have been achieved. Some other interesting properties of the turbine characteristics could also be derived from the calculations and verified by experiments. For this reason and because of not using any unreliable assumptions the calculation method has been confirmed to be self-validated. The operational instability in the upper range of the rotational speed, known as the S-shape instability, is ascribed to the total flow separation and stagnation at the impeller inlet. In that range of the rotational speed, the operation of the Francis turbine oscillates between pump and turbine mode.

  20. Numerical investigation of refrigeration machine compressor operation considering single-phase electric motor dynamic characteristics

    Baidak, Y.; Smyk, V.

    2017-08-01

    Using as the base the differential equations system which was presented in relative units for generalized electric motor of hermetic refrigeration compressor, mathematical model of the software for dynamic performance calculation of refrigeration machine compressors drive low-power asynchronous motors was developed. Performed on its ground calculations of the basic model of two-phase electric motor drive of hermetic compressor and the proposed newly developed model of the motor with single-phase stator winding, which is an alternative to the industrial motor winding, have confirmed the benefits of the motor with innovative stator winding over the base engine. Given calculations of the dynamic characteristics of compressor drive motor have permitted to determine the value of electromagnetic torque swinging for coordinating compressor and motor mechanical characteristics, and for taking them into consideration in choosing compressor elements construction materials. Developed and used in the process of investigation of refrigeration compressor drive asynchronous single-phase motor mathematical and software can be considered as an element of computer-aided design system for design of the aggregate of refrigeration compression unit refrigerating machine.

  1. Measurement of laser absorptivity for operating parameters characteristic of laser drilling regime

    Schneider, M; Berthe, L; Fabbro, R; Muller, M [Laboratoire pour l' Application des Lasers de Puissance, UPR CNRS no1578, 16 Bis, Avenue Prieur de la Cote D' Or, 94114 Arcueil Cedex (France)], E-mail: matthieu.schneider@gmail.com

    2008-08-07

    Laser drilling in the percussion regime is commonly used in the aircraft industry to drill sub-millimetre holes in metallic targets. Characteristic laser intensities in the range of 10 MW cm{sup -2} are typically employed for drilling metallic targets. With these intensities the temperature of the irradiated matter is above the vaporization temperature and the drilling process is led by hydrodynamic effects. Although the main physical processes involved are identified, this process is not correctly understood or completely controlled. A major characteristic coefficient of laser-matter interaction for this regime, which is the absorptivity of the laser on the irradiated surface, is still unknown, because of the perturbing effects due to laser beam geometrical trapping inside the drilled hole. So, by using time resolved experiments, this study deals with the direct measurement of the variation of the intrinsic absorption of aluminium, nickel and steel materials, as a function of the incident laser intensity up to 20 MW cm{sup -2}. We observe that for this incident intensity, the absorptivity can reach up to 80%. This very high and unexpected value is discussed by considering the microscopic behaviour of the heated matter near the vapour-liquid interface that undergoes possible Rayleigh-Taylor instability or volume absorption.

  2. Measurement of laser absorptivity for operating parameters characteristic of laser drilling regime

    Schneider, M.; Berthe, L.; Fabbro, R.; Muller, M.

    2008-08-01

    Laser drilling in the percussion regime is commonly used in the aircraft industry to drill sub-millimetre holes in metallic targets. Characteristic laser intensities in the range of 10 MW cm-2 are typically employed for drilling metallic targets. With these intensities the temperature of the irradiated matter is above the vaporization temperature and the drilling process is led by hydrodynamic effects. Although the main physical processes involved are identified, this process is not correctly understood or completely controlled. A major characteristic coefficient of laser-matter interaction for this regime, which is the absorptivity of the laser on the irradiated surface, is still unknown, because of the perturbing effects due to laser beam geometrical trapping inside the drilled hole. So, by using time resolved experiments, this study deals with the direct measurement of the variation of the intrinsic absorption of aluminium, nickel and steel materials, as a function of the incident laser intensity up to 20 MW cm-2. We observe that for this incident intensity, the absorptivity can reach up to 80%. This very high and unexpected value is discussed by considering the microscopic behaviour of the heated matter near the vapour-liquid interface that undergoes possible Rayleigh-Taylor instability or volume absorption.

  3. Thermal stress analysis and operational characteristics of a bellows-seal globe valve

    Kim, Kwang Su; Kim, Youn Jae

    2005-01-01

    Because of design and manufacturing costs, it is important to predict an expected life of bellows with component stresses of bellows as its design factors and material characteristics. In this study, numerical analyses are carried out to elucidate the thermal and flow characteristics with 0.1 m (4 inch) bellows-seal globe valve for high temperature (max. 600 .deg. C) and for high pressure (max. 104 kgf/cm 2 , 10.2 MPa) conditions. Using commercial codes, FLUENT, which uses FVM and SIMPLE algorithm, and ANSYS, which uses FEM, the pressure and temperature fields are calculated and the results are graphically depicted. In addition, when bellows have an axial displacement, thermal stress affecting bellows life is studied. The pressure and temperature values obtained from the flow analyses are adopted as the boundary conditions for thermal stress analyses. As the result of this study, we get the reasonable coefficients for valve and thermal stress for bellows, compared with existing coefficients and calculated values

  4. Operating characteristics and modeling of the LLNL 100-kV electric gun

    Osher, J.E.; Barnes, G.; Chau, H.H.; Lee, R.S.; Lee, C.; Speer, R.; Weingart, R.C.

    1989-01-01

    In the electric gun, the explosion of an electrically heated metal foil and the accompanying magnetic forces drive a thin flyer plate up a short barrel. Flyer velocities of up to 18 km/s make the gun useful for hypervelocity impact studies. The authors briefly review the technological evolution of the exploding-metal circuit elements that power the gun, describe the 100-kV electric gun designed at Lawrence Livermore National Laboratory (LLNL) in some detail, and present the general principles of electric gun operation. They compare the experimental performance of the LLNL gun with a simple model and with predictions of a magnetohydrodynamics code

  5. Effect of operating parameters of a burner of oxygen conversion on flame characteristics

    Glike, A P

    1980-01-01

    Combustion of high-calorie gases under pressure makes it possible to create compact fuel-burning devices. As applied to open-hearth furnaces, several types of these devices have been developed. The oxidizer used is oxygen, blowing, enriched with oxygen or compressed air. Reformation of natural gas in the chamber of the burner of oxygen conversion operating under pressure up to 2 kg-f/cm/sup 2/ makes it possible to obtain a high-temperature flame with satisfactory illumination without using mazut.

  6. Detection mechanism and characteristics of ZnO-based N2O sensors operating with photons

    Jeong, T. S.; Yu, J. H.; Mo, H. S.; Kim, T. S.; Youn, C. J.; Hong, K. J.

    2013-11-01

    N2O sensors made with ZnO-based ZnCdO films were grown on Pyrex substrates by using the RF co-sputtering method. The structure of the N2O sensor was electrode/sensor/glass/illuminant. The mechanism of the photo-assisted oxidation and reduction process on the surface of the N2O sensors was investigated using light from a UV lamp and violet light emitting diode (LED). For photon exposure wavelengths of 365 and 405 nm, the sensitivity of the ZnO-based ZnCdO sensors was measured. From these measurements, the values of the sensitivity of the sensors with x = 0, 0.01, and 0.05 were found to be S = 1.44, 1.39, and 1.33 under LED light with a wavelength of 405 nm, respectively. These sensitivities were compared to those of SnO2 and WO3 materials measured at operating temperatures of 300-600 °C. Also, under exposure with UV light, the response times were observed to be 130 to 270 sec. These response times were slightly slower than that for the traditional method of thermal heating. However, they indicate that the described photon exposure method for N2O detection can replace the conventional heating mode. Consequently, we demonstrated that portable N2O sensors for room-temperature operation could be fabricated without thermal heating.

  7. Enzymatic AND logic gates operated under conditions characteristic of biomedical applications.

    Melnikov, Dmitriy; Strack, Guinevere; Zhou, Jian; Windmiller, Joshua Ray; Halámek, Jan; Bocharova, Vera; Chuang, Min-Chieh; Santhosh, Padmanabhan; Privman, Vladimir; Wang, Joseph; Katz, Evgeny

    2010-09-23

    Experimental and theoretical analyses of the lactate dehydrogenase and glutathione reductase based enzymatic AND logic gates in which the enzymes and their substrates serve as logic inputs are performed. These two systems are examples of the novel, previously unexplored class of biochemical logic gates that illustrate potential biomedical applications of biochemical logic. They are characterized by input concentrations at logic 0 and 1 states corresponding to normal and pathophysiological conditions. Our analysis shows that the logic gates under investigation have similar noise characteristics. Both significantly amplify random noise present in inputs; however, we establish that for realistic widths of the input noise distributions, it is still possible to differentiate between the logic 0 and 1 states of the output. This indicates that reliable detection of pathophysiological conditions is indeed possible with such enzyme logic systems.

  8. MAIN CHARACTERISTICS OF COMPANIES USING SERVICE ORIENTED ARCHITECTURE (SOA AND OF THEIR OPERATION CONTEXT

    Alfonso Duran Heras

    2008-12-01

    Full Text Available The aim of this article is to establish the main characteristics of the organizations that have successfully implemented information systems based on Service Oriented Architecture (SOA. Their environmental circumstances have also been studied. To achieve this objective, a SOA bibliographic review has been carried out, encompassing an analysis of 25 real cases in which different SOA applications were successfully implemented. All these cases were published between 2.001 and 2.007. The conclusions of this article can be briefly summarized as follows: SOA is well suited for organizations that rely on important legacy systems, whose performance is hindered by the lack of integration and flexibility of their computer architectures. These organizations therefore need to improve such architectures rather than replace them by new systems; SOA is being used by organizations that need to integrate their systems with those of their supply chain partners; SOA solutions provide support for the use of Web technologies.

  9. Fuel characteristics needed for optimal operation of the BR2 reactor

    Koonen, E.; Beeckmans, A.; Gubel, P.

    1998-01-01

    The standard BR2 fuel element contains 400 g 235 U under the form of UAl x with burnable absorbers homogeneously mixed into the fuel meat. The uranium is highly enriched with a density of ∼1.30 g U/cm 3 . This fuel element was developed in the early seventies to satisfy the irradiation conditions required by many experimental programmes: large reactivity available, cycle length, hard neutron spectrum, limited motion of the control rods during the cycle thereby stabilizing the irradiation conditions. Another benefit is the reduction of the fuel consumption by increasing the burnup at discharge. BR2 has recently been restarted after the completion of an important refurbishment programme. Future utilization will again be concentrated on engineering R and D in the field of nuclear fuels, materials and safety, and on radioisotope production. Therefore the required irradiation conditions and the corresponding fuel characteristics remain essentially the same as in the past. (author)

  10. Some characteristics in operation of long exploited oil fields in Fergana depression. [USSR

    Gordinskii, E V; Ovanesov, M G; Irmatov, E K

    1969-01-01

    A review of geological and oil production data from 3 Fergana fields is presented. The reservoirs are small, tectonically bounded, and are anticlines of Paleogenic carbonates. Reservoirs are heterogeneous with porosity ranging from 3 to 25% and permeability ranging from a few to 500 md. Some of the reservoirs have expanding gas caps, some are solution drive, and others have been waterflooded. All are now in the final stage of depletion. Production history and characteristics of each group are given. One way of increasing present production rate appears to be injection of gas or air into the reservoirs. This can be done inexpensively, since additional injection wells would not have to be drilled and some produced gas is available. Increased fluid withdrawal from present wells should also be beneficial.

  11. A study on a characteristic of stem friction coefficient for motor operated flexible wedge gate valve

    Kim, Dae-Woong; Park, Sung-Geun; Lee, Sang-Guk; Kang, Shin-Cheul

    2009-01-01

    Stem friction coefficient is a coefficient that represents friction between thread leads of the stem and stem nut. It is an important factor to determine output thrust delivered from the actuator to the valve stem in assessing performance of motor operated valves. This study analyzes the effects of changes in differential pressure on stem friction coefficient, and determines the bounding value of stem friction coefficient. A dynamic test was conducted on multiple flexible wedge gate valves in various differential pressure conditions, and the test data was statistically analyzed to determine the bounding value. The results show that stem friction coefficient in middle and high differential pressure is influenced by fluid pressure, while stem friction coefficient in low differential pressure is almost not affected by fluid pressure. In addition, it is found that the bounding value of stem friction coefficient is higher in a closing stroke than in an opening stroke.

  12. Exergy characteristics of a ceiling-type residential air conditioning system operating under different climatic conditions

    Ozbek, Arif [Dept. of Mechanical Engineering, Ceyhan Engineering Faculty, Cukurova University, Adana (Turkmenistan)

    2016-11-15

    In this study an energy and exergy analysis of a Ceiling-type residential air conditioning (CTRAC) system operating under different climatic conditions have been investigated for provinces within the different geographic regions of Turkey. Primarily, the hourly cooling load capacities of a sample building (Q{sub evap}) during the months of April, May, June, July, August and September were determined. The hourly total heat gain of the sample building was determined using the Hourly analysis program (HAP). The Coefficient of performance (COP), exergy efficiency (η) and exergy destruction (Ex{sub dest}) values for the whole system and for each component were obtained. The results showed that lower atmospheric temperature (T{sub atm}) influenced the performance of the system and each of its components.

  13. [Characteristics of the provision of hemotransfusion materials to the wounded and patients during antiterrorist operation].

    Chechetkin, A V; Popova, N N; Kuz'min, N S; Fedotov, Iu P

    2004-01-01

    The authors analyze the experience of organization of the wounded and patient provision with hemotransfusion materials to render assistance during antiterrorist operation in Republic of Dagestan and Republic of Chechnya in 1999-2001. It is shown that supply of military treatment-and-prophylactic institutions deployed in the zone of military conflict, of specialized hospitals with hemotransfusion materials was the following: with blood preparations (at the expense of centralized deliveries), with blood components (91.8%, at the expense of centralized deliveries form the district blood transfusion station). The volume of stored blood taken from emergency reserve donors in the military treatment-and-prophylactic institutions located near the zone of military actions constituted 8.2% of the total volume of blood components received.

  14. Vibration and Operational Characteristics of a Composite-Steel (Hybrid) Gear

    Handschuh, Robert F.; LaBerge, Kelsen E.; DeLuca, Samuel; Pelagalli, Ryan

    2014-01-01

    Hybrid gears have been tested consisting of metallic gear teeth and shafting connected by composite web. Both free vibration and dynamic operation tests were completed at the NASA Glenn Spur Gear Fatigue Test Facility, comparing these hybrid gears to their steel counterparts. The free vibration tests indicated that the natural frequency of the hybrid gear was approximately 800 Hz lower than the steel test gear. The dynamic vibration tests were conducted at five different rotational speeds and three levels of torque in a four square test configuration. The hybrid gears were tested both as fabricated (machined, composite layup, then composite cure) and after regrinding the gear teeth to the required aerospace tolerance. The dynamic vibration tests indicated that the level of vibration for either type of gearing was sensitive to the level of load and rotational speed.

  15. Thermal-hydraulic characteristics of pressurized water reactors during commercial operation. Pt. 5

    Procaccia, H.; David, J.; Wazzan, A.R.

    1984-01-01

    Measured downcomer water and metal shell temperatures in the steam generator No. 20 of the PWR Tricastin 1 show that the downcomer flows is of the swirling type, just as found previously in Bugey 4. A comparison of results for Tricastin 1 and Bugey 4 shows that the addition in Tricastin 1 of a flow distribution baffle plate, between the tube sheet and the first cross plate, while reducing the height of the opening between the tube sheet and the shell surrounding the bundle, may have resulted in the observed reduction (by a factor one half) of sludge deposit upon the tube sheet in Tricastin 1, and in fixing, with extended period of operation, the boiling zone in the cold leg (a desired event) and near the tube-free tube lane. (orig.)

  16. The paradox of characteristics of silicon detectors operated at temperature close to liquid helium

    Eremin, V.; Shepelev, A.; Verbitskaya, E.; Zamantzas, C.; Galkin, A.

    2018-05-01

    The aim of this study is to give characterization of silicon p+/n/n+ detectors for the monitoring systems of the Large Hadron Collider machine at CERN with the focus on justifying the choice of silicon resistivity for the detector operation at the temperature of 1.9-10 K. The detectors from n-type silicon with the resistivity of 10, 4.5, and 0.5 kΩ cm were investigated at the temperature from 293 up to 7 K by the Transient Current Technique with a 660 nm pulse laser and alpha-particles. The shapes of the detector current pulse response allowed revealing a paradox in the properties of shallow donors of phosphorus, i.e., native dopants in the n-type Si. There was no carrier freeze-out on the phosphorus energy levels in the space charge region (SCR), and they remained positively charged irrespective of temperature, thus limiting the depleted region depth. As for the base region of a partially depleted detector, the levels became neutral at T < 28 K, which transformed silicon to an insulator. The reduction of the activation energy for carrier emission in the detector SCR estimated in the scope of the Poole-Frenkel effect failed to account for the impact of the electric field on the properties of phosphorus levels. The absence of carrier freeze-out in the SCR justifies the choice of high resistivity silicon as the only proper material for detector operation in a fully depleted mode at extremely low temperature.

  17. Gait characteristics before hardware removal in patients operated upon for tibial plateau fractures.

    Deleanu, Bogdan; Prejbeanu, Radu; Crisan, Dan; Predescu, Vlad; Popa, Iulian; Poenaru, Dan V

    2015-07-01

    The reporting of gait analysis data on operated fractures of the tibial plateau, while extensive for studies of knee osteoarthritis of mostly undisclosed aetiology and ACL deficient knees, is rather limited in literature. In the present study we investigated 25 tibial plateau fractures classified as Schatzker II, IV, V and VI that underwent operative reduction and lateral plate osteosynthesis. Apart from routine radiographic exploration and patient completed (KOOS) scores at three (mean of 3.2 months), six (mean of 5.6 months) and 12 months (mean of 11.3 months) postoperatively, gait analysis was performed at these intervals as well. Cadence, step time and knee flexion were the gait parameters that were selected for the comparison at six and 12 months postoperatively. The analysed gait parameters were significantly improved between the six and the 12-month session and statistically significant differences were found between the two groups of values. Cadence had a mean value of 41 steps/minute at six months and 45 steps/minute at 12 months (p = 0.99). Step time was a mean of 0.74 seconds at six months while at 12 months the median value was 0.66 seconds (p = 0.94). Knee flexion angles evolved in a similar manner with mean values of 58° at six months and 69° at 12 months (p = 0.95). The mean KOOS scores were 42.4, 56.3 and 67.99 at three, six and 12 months postoperatively, respectively. Complex intra-articular fractures, classified as Schatzker IV, V and VI, had a higher impact on joint function than Schatzker II fractures treated with similar techniques and implants. There were statistically significant improvements in the recovery status at 12 months postoperatively compared to six months with extended chances for improvement.

  18. Design and Operating Characteristics of High-Speed, Small-Bore, Angular-Contact Ball Bearings

    Pinel, Stanley I.; Signer, Hans R.; Zaretsky, Erwin V.

    1998-01-01

    The computer program SHABERTH was used to analyze 35-mm-bore, angular-contact ball bearings designed and manufactured for high-speed turbomachinery applications. Parametric tests of the bearings were conducted on a high-speed, high-temperature bearing tester and were compared with the computer predictions. Four bearing and cage designs were studied. The bearings were lubricated either by jet lubrication or through the split inner ring with and without outer-ring cooling. The predicted bearing life decreased with increasing speed because of increased operating contact stresses caused by changes in contact angle and centrifugal load. For thrust loads only, the difference in calculated life for the 24 deg. and 30 deg. contact-angle bearings was insignificant. However, for combined loading, the 24 deg. contact-angle bearing gave longer life. For split-inner-ring bearings, optimal operating conditions were obtained with a 24 deg. contact angle and an inner-ring, land-guided cage, using outer-ring cooling in conjunction with low lubricant flow rates. Lower temperature and power losses were obtained with a single-outer-ring, land-guided cage for the 24 deg. contact-angle bearing having a relieved inner ring and partially relieved outer ring. Inner-ring temperatures were independent of lubrication mode and cage design. In comparison with measured values, reasonably good engineering correlation was obtained using the computer program SHABERTH for predicted bearing power loss and for inner- and outer-ring temperatures. The Parker formula for XCAV (used in SHABERTH, a measure of oil volume in the bearing cavity) may need to be refined to reflect bearing lubrication mode, cage design, and location of cage-controlling land.

  19. Operational characteristics of the NNPB plunger in the glass container industry

    Penlington, Roger

    Although glass containers are an everyday item the process responsible for their production is not scientifically understood. Developments have occurred slowly over many years, mostly on a trial and error basis and in response to economic pressures. The narrow neck press and blow (NNPB) process has evolved in recent years as a result of attempts to reduce container weight. The fundamental component of the NNPB process is the plunger which is responsible for the initiation of the cavity and control of glass distribution within the container.The NNPB plunger functions as a form tool and as a heat exchanger, thus requiring a carefully selected range of properties. The Engineer responsible for tooling selection and operation has a limited resource of scientific knowledge to enable the performance of the process to be optimised.The current NNPB plunger is subject to high rates of wear and is directly responsible for product defects, thermal instability and limits process speed.The work presented here is a scientific study of current NNPB plunger technology. The plunger has been investigated in relation to the requirements of the glass container forming process. The materials used have been examined, before and after use and their wear modes explained. The thermal properties of the plunger have, as far as is possible, been examined during the forming cycle. When combined with results from the characterisation of transformations occurring in the material, during its service life, operational requirements have been explained. The ability of the NNPB plunger to remove heat from the glass has been investigated, and has illustrated significant deficiencies in the current arrangement. Details are given as to how these deficiencies may be overcome to enable the Engineer to regain control of the process.As a result of the study many phenomena exhibited by the NNPB plunger are now understood and may be related to the performance of the process.

  20. AN EVALUATION OF PHOTOVOLTAIC SYSTEMS MPPT TECHNIQUES UNDER THE CHARACTERISTICS OF OPERATIONAL CONDITIONS

    I. A. Elzein

    2017-01-01

    Full Text Available In this article an extended literature surveying review is launched on a set of comparative studies of maximum power point tracking (MPPT techniques. Different MPPT methods are addressed with an ultimate aim of how to be maximizing the PV system output power by tracking Pmax in a set of different operational circumstances. In this paper maximum power point tracking, MPPT techniques are reviewed on basis of different parameters related to the design simplicity and/or complexity, implementation, hardware required, and other related aspects.he technology of solar systems has been booming for a while due to its ability to replace current fossil fuels like coal and gas for generation of electricity that produce air, water, and land pollution. In addition it decreased the issue of global warming and climate changes substantially due to being produced in a clean environmental manner and was proved to be an Eco-friendly resource of energy. The photovoltaic systems’ manufacturing process has been improving continuously over the last decade and photovoltaic systems have become an interesting solution. Precisely, PV systems are constituted from arrays of photovoltaic cells, choppers (mainly buck-boost or boost DC/DC converter, MPPT control systems and storage devices and/or grid connections. To improve the efficiency of such systems, various studies have been performed. The demand of PV generation systems seems to be increased for both standalone and grid-connected modes of PV systems. Therefore, an efficient maximum power point tracking (MPPT technique is necessary to initialize the process of tracking the maximum power point MPP at all environmental conditions and then force the PV system to operate at that MPP point.

  1. Characteristic time series and operation region of the system of two tank reactors (CSTR) with variable division of recirculation stream

    Merta, Henryk

    2006-01-01

    The paper deals with a system of a cascade of two tank reactors, being characterized by the variable stream of recirculating fluid at each stage. The assumed mathematical model enables one to determine the system's dynamics for the case when there is no time delay and for the opposite case. The time series of the conversion degree and of the dimensionless fluid temperature, characteristic for the system considered as well as the operation regions-the latter-basing on Feingenbaum diagrams with respect to the division ratio of the recirculating stream are presented

  2. Comparative survey of site and personnel monitoring characteristics for operation of various types of diagnostic-X ray equipment

    Lyarskij, P.P.; Zol'nikova, N.I.

    1977-01-01

    Diagnostic X-ray machines in present use at medical facilities differ in design and operating parameters, this diversity producing, in turn, a variety of local radiological situations and levels of personnel exposure. Based on radiological safety characterization of working conditions, the authors present a breakdown of contemporary diagnostic X-ray equipment types, based on detailed examination of each group in terms of their associated site monitoring and dosimetry patterns. The paper reports data on personnel exposure levels not only as a function of equipment design and operating characteristics but also according to types of occupational activities for particular medical personnel groups (radiologists, surgeons, anesthesiologists, etc.). Included are health physics data for domestic and foreign X-ray equipment, levels of local and absorbed doses for radiologists, cardiovascular surgeons, neurosurgeons, urologists, traumatologists, anesthesiologists, etc. Measures are recommended for optimizing their activities from the standpoint of radiation safety. (author)

  3. Study on magnetic fluid optical fiber devices for optical logic operations by characteristics of superparamagnetic nanoparticles and magnetic fluids

    Chieh, J. J.; Hong, C. Y.; Yang, S. Y.; Horng, H. E.; Yang, H. C.

    2010-01-01

    We propose two optical fiber-based schemes using two magnetic fluid optical fiber modulators in series or in parallel for optical logic signal processing and operation. Here, each magnetic fluid optical fiber modulator consists of a bare multimode fiber surrounded by magnetic fluid in which the refractive index is adjustable by applying external magnetic fields amplifying the input electrical signal to vary the transmission intensity of the optical fiber-based scheme. The physical mechanisms for the performances of the magnetic fluid optical fiber devices, such as the transmission loss related to Boolean number of the logic operation as well as the dynamic response, are studied by the characteristics of superparamagnetic nanoparticles and magnetic fluids. For example, in the dynamic response composed of the retarding and response sub-procedures except the response times of the actuation coil, the theoretical evaluation of the retarding time variation with cladding magnetic fluids length has good agreement with the experimental results.

  4. Influence of Compression Ratio on the Performance and Emission Characteristics of Annona Methyl Ester Operated DI Diesel Engine

    Senthil Ramalingam

    2014-09-01

    Full Text Available This study aims to find the optimum performance and emission characteristics of single cylinder variable compression ratio (VCR engine with different blends of Annona methyl ester (AME as fuel. The performance parameters such as specific fuel consumption (SFC, brake thermal efficiency (BTE, and emission levels of HC, CO, Smoke, and NOx were compared with the diesel fuel. It is found that, at compression ratio of 17: 1 for A20 blended fuel (20% AME + 80% Diesel shows better performance and lower emission level which is very close to neat diesel fuel. The engine was operated with different values of compression ratio (15, 16, and 17 to find out best possible combination for operating engine with blends of AME. It is also found that the increase of compression ratio increases the BTE and reduces SFC and has lower emission without any engine in design modifications.

  5. Performance and emission characteristics of compression ignition engine operating with false flax biodiesel and butanol blends

    Mustafa Atakan Akar

    2016-02-01

    Full Text Available In this study, fuel properties, engine performance, and emission characteristics of diesel fuel, false flax biodiesel, and their blends with butanol have been evaluated. Blend ratios used in this study were diesel–biodiesel–butanol (70% diesel–20% biodiesel–10% butanol and 60% diesel–20% biodiesel–20% butanol by volume and biodiesel–diesel (20% biodiesel–80% diesel and 100% biodiesel by volume. Experiments showed that 10% alcohol addition to diesel and biodiesel fuels caused a decrease in torque value up to 8.57%. When butanol ratio raised to 20%, torque value decreased to an average of 12.7% and power values decreased to an average of 13.57%. Specific fuel consumption increased to an average of 10.63% and 12.80% with 10% and 20% butanol addition, respectively. Alcohol addiction into conventional diesel and biodiesel fuel slightly increased NOX emissions. Supplement of alcohol decreased CO and CO2 emissions when it was entrained to diesel and increased it when it was added to biodiesel. It means that addition of alcohol to diesel changed CO and CO2 emissions.

  6. Operation characteristics of SFCLs combined with a transformer in three-phase power system

    Jung, B. I.; Choi, H. S. [Chosun University, Gwangju (Korea, Republic of)

    2013-12-15

    The studies of superconducting fault current limiter (SFCL) for reduction of the fault current are actively underway in the worldwide. In this paper, we analyzed the characteristics of a new type SFCL using the conventional transformer and superconducting elements combined mutually. The secondary and third windings of this SFCL were connected the load and the superconducting element, respectively. The electric power was provided to load connected to secondary windings of the transformer in normal state of power system. On the other hand, when the fault occurred in power system, the fault current was limited by closing the line of third winding of the transformer. At this time, the ripple phenomenon of the fault was minimized by opening the fault line in secondary winding of a transformer in power system. The sensing of the fault state was performed by the CT(current transformer) and then turn-on and turn-off switching behavior of the SFCL was performed by the SCR(silicon-controlled rectifier). As a result, the proposed SFCL limited the fault current within a half-cycle efficiently. We confirmed that the fault current limitation rate was changed according to the winding ratio of a transformer.

  7. PERFORMANCE AND EMISSION CHARACTERISTICS OF A CI ENGINE OPERATED ON VEGETABLE OILS AS ALTERNATIVE FUELS

    K. Rajagopal

    2011-12-01

    Full Text Available An experimental analysis was done using a four-stroke, single cylinder, constant speed, water-cooled diesel engine, which was interfaced with Engine software. Performance and emission characteristics were evaluated for three non-edible vegetable oils, i.e. thumba, jojoba, neem oil, as well as jojoba methyl ester, to study the effect of injection pressure at 205, 220, 240 and 260 bar with a variation in injection timing at 23°bTDC and 28°bTDC. The performance of jojoba methyl ester improved with an increase in injection pressure. A maximum brake thermal efficiency of 29.72% was obtained with lower emissions compared to the other vegetable oils; this might be explained by low viscosity and better combustion. Further investigations were carried out with a new lubricant, SAE 5W-30, which improved the performance of the CI engine by 1.59%. All of the abovementioned investigations were fruitful and these results are expected to lead to substantial contributions in the development of a viable vegetable oil engine.

  8. Operation characteristics of SFCLs combined with a transformer in three-phase power system

    Jung, B. I.; Choi, H. S.

    2013-01-01

    The studies of superconducting fault current limiter (SFCL) for reduction of the fault current are actively underway in the worldwide. In this paper, we analyzed the characteristics of a new type SFCL using the conventional transformer and superconducting elements combined mutually. The secondary and third windings of this SFCL were connected the load and the superconducting element, respectively. The electric power was provided to load connected to secondary windings of the transformer in normal state of power system. On the other hand, when the fault occurred in power system, the fault current was limited by closing the line of third winding of the transformer. At this time, the ripple phenomenon of the fault was minimized by opening the fault line in secondary winding of a transformer in power system. The sensing of the fault state was performed by the CT(current transformer) and then turn-on and turn-off switching behavior of the SFCL was performed by the SCR(silicon-controlled rectifier). As a result, the proposed SFCL limited the fault current within a half-cycle efficiently. We confirmed that the fault current limitation rate was changed according to the winding ratio of a transformer.

  9. Improvement in operational characteristics of KEPCO’s line-commutation-type superconducting hybrid fault current limiter

    Yim, S.-W.; Park, B.-C.; Jeong, Y.-T.; Kim, Y.-J.; Yang, S.-E.; Kim, W.-S.; Kim, H.-R.; Du, H.-I.

    2013-01-01

    A 22.9 kV class hybrid fault current limiter (FCL) developed by Korea Electric Power Corporation and LS Industrial Systems in 2006 operates using the line commutation mechanism and begins to limit the fault current after the first half-cycle. The first peak of the fault current is available for protective coordination in the power system. However, it also produces a large electromagnetic force and imposes a huge stress on power facilities such as the main transformer and gas-insulated switchgear. In this study, we improved the operational characteristics of the hybrid FCL in order to reduce the first peak of the fault current. While maintaining the structure of the hybrid FCL system, we developed a superconducting module that detects and limits the fault current during the first half-cycle. To maintain the protective coordination capacity, the hybrid FCL was designed to reduce the first peak value of the fault current by up to approximately 30%. The superconducting module was also designed to produce a minimum AC loss, generating a small, uniform magnetic field distribution during normal operation. Performance tests confirmed that when applied to the hybrid FCL, the superconducting module showed successful current limiting operation without any damage.

  10. The stress characteristics of plate-fin structures at the different operation parameters of LNG heat exchanger

    Ma Hongqiang

    2018-01-01

    Full Text Available In this paper, the stresses of plate-fin structures at the different operation parameters were analyzed in actual operation process of LNG plate-fin heat exchanger based on finite element method and thermal elastic theory. Stress characteristics of plate-fin structures were investigated at the different operation parameters of that. The results show that the structural failure of plate-fin structures is mainly induced by the maximum shear stress at the brazing filler metal layer between plate and fin while by the maximum normal stress in the region of brazed joint near the fin side. And a crack would initiate in brazed joint near the fin side. The maximum normal stress is also main factor to result in the structural failure of plate-fin structures at the different temperature difference (between Natural Gas (NG and Mixture Refrigerant (MR, MR temperature and NG pressure of LNG heat exchanger. At the same time, the peak stresses obviously increase as the temperature difference, MR temperature and NG pressure increase. These results will provide some constructive instructions in the safe operation of LNG plate-fin heat exchanger in a large-scale LNG cold-box.

  11. The design and characteristics of direct current glow discharge atomic emission source operated with plain and hollow cathodes

    Qayyum, A.; Mahmood, M.I.

    2008-01-01

    A compact direct current glow discharge atomic emission source has been designed and constructed for analytical applications. This atomic emission source works very efficiently at a low-input electrical power. The design has some features that make it distinct from that of the conventional Grimm glow discharge source. The peculiar cathode design offered greater flexibility on size and shape of the sample. As a result the source can be easily adopted to operate in Plain or Hollow Cathode configuration. I-V and spectroscopic characteristics of the source were compared while operating it with plain and hollow copper cathodes. It was observed that with hollow cathode, the source can be operated at a less input power and generates greater Cu I and Cu II line intensities. Also, the intensity of Cu II line rise faster than Cu I line with argon pressure for both cathodes. But the influence of pressure on Cu II lines was more significant when the source is operated with hollow cathode

  12. A Statewide Examiniation of Mental Health Courts in Illinois: Program Characteristics and Operations

    Arthur J. Lurigio

    2015-07-01

    Full Text Available This study represents the only broad-based, statewide evaluation of mental health courts (MHCs conducted to date.  Data were collected from 2010 to 2013 at each of the nine active MHC programs operating in Illinois at the start of the study. The purpose of the study was to compare and contrast the adjudicatory and supervisory models of each established Illinois MHC program by utilizing a variety of research methodologies. A four-year recidivism analysis of case-level data from three Illinois MHCs was also conducted. Illinois MHCs were largely characterized by the '10 essential elements of an MHC', such as voluntary participation, informed choice and hybrid team approaches to case manage clients. Results of the recidivism analysis suggest that MHCs compare favorably to other types of probation. Overall, findings revealed that Illinois MHCs are delivering services effectively and efficiently in a well-coordinated, client-centered team approach. Differences found among the MHCs are not evidence of significant variance from the model, and instead represent responsiveness to the unique culture of the court, the niche-filling character of the program, the expectations of the program stakeholders and the nature and extent of the local service environment.

  13. Study on the phosphate reaction characteristics of lanthanide chlorides in molten salt with operating conditions

    Lee, Tae-Kyo; Hwang, Taek-Sung; Cho, Yung-Zun; Eun, Hee-Chul; Park, Hwan-Seo; Park, Geun-Il; Son, Sung-Mo

    2013-01-01

    A minimization of waste salt is one of the most important issues for the optimization of pyroprocessing. The separation of fission products in waste salts and the reuse of purified waste salt are promising strategies for minimizing the waste salt amounts. The phosphate precipitation of lanthanide is currently being considered for eutectic (LiCl–KCl) waste salt purification. In this research, the effects of molten salt temperature (400–550°C) and reaction time (max. 180 min) upon conversion into the phosphate of lanthanides was investigated using 1 and 3 kg of eutectic salt. The conversion efficiency of lanthanides to molten salt-insoluble precipitates and phosphates was increased with an increase in molten salt temperature and operating time until it attained a specific temperature and time. K 3 PO 4 as a precipitant was more favorable than Li 3 PO 4 in terms of reactivity. To obtain over a 99% overall conversion efficiency, about 30 min was required in the case of using K 3 PO 4 at 450°C, but about 120 min in the case of using Li 3 PO 4 at 550°C. The lanthanide precipitates formed by a reaction with phosphate were a mixture of monoclinic structures, usually representing a polyhedron structure, and a tetragonal structure, representing a platelet structure. (author)

  14. Characteristics and quality of intra-operative cell salvage in paediatric scoliosis surgery.

    Perez-Ferrer, A; Gredilla-Díaz, E; de Vicente-Sánchez, J; Navarro-Suay, R; Gilsanz-Rodríguez, F

    2016-02-01

    To determine the haematological and microbiological characteristics of blood recovered by using a cell saver with a rigid centrifuge bowl (100ml) in paediatric scoliosis surgery and to determine whether it conforms to the standard expected in adult patients. A cross-sectional, descriptive cohort study was performed on 24 consecutive red blood cell (RBC) units recovered from the surgical field and processed by a Haemolite® 2+ (Haemonetics Corp., Braintree, MA, EE. UU.) cell saver. Data were collected regarding age, weight, surgical approach (anterior or posterior), processed shed volume and volume of autologous RBC recovered, full blood count, and blood culture obtained from the RBC concentrate, and incidence of fever after reinfusion. The processed shed volume was very low (939±569ml) with high variability (coefficient of variation=0.6), unlike the recovered volume 129±50ml (coefficient of variation=0.38). A statistically significant correlation between the processed shed volume and recovered RBC concentrate haematocrit was found (Pearson, r=.659, P=.001). Haematological parameters in the recovered concentrate were: Hb 11±5.3g dl(-1); haematocrit: 32.1±15.4% (lower than expected); white cells 5.34±4.22×103 ul(-)1; platelets 37.88±23.5×103 ul(-1) (mean±SD). Blood culture was positive in the RBC concentrate recovered in 13 cases (54.2%) in which Staphylococcus coagulase (-) was isolated. Cell salvage machines with rigid centrifuge bowls (including paediatric small volume) do not obtain the expected haematocrit if low volumes are processed, and therefore they are not the best choice in paediatric surgery. Copyright © 2015 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

  15. Enhancing the ecological and operational characteristics of water treatment units at TPPs based on baromembrane technologies

    Chichirova, N. D.; Chichirov, A. A.; Filimonova, A. A.; Saitov, S. R.

    2017-12-01

    The innovative baromembrane technologies for water demineralization were introduced at Russian TPPs more than 25 years ago. While being used in the power engineering industry of Russia, these technologies demonstrated certain advantages over the traditional ion-exchange and thermal technologies of makeup water treatment for steam boilers. Water treatment units based on the baromembrane technology are compact, easy to operate, and highly automated. The experience gained from the use of these units shows that their reliability depends directly on preliminary water treatment. The popular water pretreatment technology with coagulation by aluminum oxychloride proved to be inefficient during the seasonal changes of source water quality that occurs at some stations. The use of aluminum coagulant at pH 8 and higher does not ensure the stable and qualitative pretreatment regime: soluble aluminum forms slip on membranes of the ultrafiltration unit, thereby causing pollution and intoxication as well as leading to structural damages or worsening of mechanical properties of the membranes. The problem of increased pH and seasonal changes of the source water quality can be solved by substitution of the traditional coagulant into a new one. To find the most successful coagulant for water pretreatment, experiments have been performed on both qualitative and quantitative analysis of the content of natural organic matters in the Volga water and their structure. We have developed a software program and measured the concentrations of soluble aluminum and iron salts at different pH values of the source water. The analysis of the obtained results has indicated that iron sulfate at pH 6.0-10.2, in contrast to aluminum oxychloride, is not characterized by increased solubility. Thus, the basic process diagrams of water pretreatment based on baromembrane technologies with pretreatment through coagulation by iron salts and wastewater amount reducing from 60-40 to 5-2% have been introduced for

  16. Understanding Hydrothermal Dechlorination of PVC by Focusing on the Operating Conditions and Hydrochar Characteristics

    Tian Li

    2017-03-01

    Full Text Available To remove chlorine from chlorinated wastes efficiently, the hydrothermal treatment (HT of PVC was investigated with a lower alkaline dosage in this work. Some typical operating conditions were investigated to find out the most important factor affecting the dechlorination efficiency (DE. The FTIR technique was employed to detect the functional groups in PVC and hydrochars generated to reveal the possible pathways for chlorine removal. The results show that the HT temperature was a key parameter to control the dechlorination reaction rate. At a HT temperature of 240 °C, about 94.3% of chlorine could be removed from the PVC with 1% NaOH. The usage of NaOH was helpful for chlorine removal, while a higher dosage might also hinder this process because of the surface poisoning and coverage of free sites. To some extent, the DE was increased with the residence time. At a residence time of 30 min, the DE reached a maximum of 76.74%. A longer residence time could promote the generation of pores in hydrochar which is responsible for the reduction in DE because of the re-absorption of water-soluble chlorine. According to the FTIR results, the peak intensities of both C=CH and C=C stretching vibrations in hydrochar were increased, while the peak at around 3300 cm−1 representing the –OH group was not obvious, indicating that the dehydrochlorination (elimination reaction was a main route for chlorine removal under these conditions studied in this work.

  17. Evaluation of the diagnostic performance and operational characteristics of four rapid immunochromatographic syphilis tests in Burkina Faso.

    Bocoum, Fadima Yaya; Ouédraogo, Henri; Tarnagda, Grissoum; Kiba, Alice; Tiendrebeogo, Simon; Bationo, Fabrice; Liestman, Benjamin; Diagbouga, Serge; Zarowsky, Christina; Traoré, Ramata Ouédraogo; Kouanda, Séni

    2015-06-01

    Little information is available on the rapid diagnostic testing for syphilis in Burkina Faso. The objectives of the study were (i) to assess the sensitivity and specificity of four on site rapid tests in comparison with Treponema pallidum haemagglutination assay (TPHA) as a gold standard and (ii) to evaluate the operational characteristics of those tests among health workers in a maternity unit. Four rapid syphilis tests commercially available in Burkina Faso were evaluated using archived serum samples and Treponema pallidum hemagglutination assay (TPHA) as the gold standard. Blood samples were collected between November 2011 and June 2012 from blood donors at the Regional Blood Transfusion Center of Ouagadougou. The sensitivity and specificity of the tests were calculated. Evaluation of operational characteristics such as clarity of pamphlet, complexity of technique, duration, was conducted in a first-level healthcare center with health workers in maternity unit. Alere DetermineTM Syphilis was the most sensitive of the four rapid syphilis tests evaluated. It was followed by SD Bioline Syphilis 3.0, Cypress Diagnostics Syphilis Quick test and Accu-Tell ® Rapid Anti-TP, which was the least sensitive. The four tests demonstrated a good diagnostic specificity for syphilis (95-98%), and healthcare workers found them easy to use. The study allowed confirming the good performance of three of four rapid syphilis tests in Burkina Faso. More research will be conducted to assess the feasibility of introducing selected rapid tests for syphilis in antenatal care services.

  18. A Comparison of the Characteristics of Planar and Axisymmetric Bluff-Body Combustors Operated under Stratified Inlet Mixture Conditions

    G. Paterakis

    2013-01-01

    Full Text Available The work presents comparisons of the flame stabilization characteristics of axisymmetric disk and 2D slender bluff-body burner configurations, operating with inlet mixture stratification, under ultralean conditions. A double cavity propane air premixer formed along three concentric disks, supplied with a radial equivalence ratio gradient the afterbody disk recirculation, where the first flame configuration is stabilized. Planar fuel injection along the center plane of the leading face of a slender square cylinder against the approach cross-flow results in a stratified flame configuration stabilized alongside the wake formation region in the second setup. Measurements of velocities, temperatures, OH∗ and CH∗ chemiluminescence, local extinction criteria, and large-eddy simulations are employed to examine a range of ultralean and close to extinction flame conditions. The variations of the reacting front disposition within these diverse reacting wake topologies, the effect of the successive suppression of heat release on the near flame region characteristics, and the reemergence of large-scale vortical activity on approach to lean blowoff (LBO are investigated. The cross-correlation of the performance of these two popular flame holders that are at the opposite ends of current applications might offer helpful insights into more effective control measures for expanding the operational margin of a wider range of stabilization configurations.

  19. Interrelationships Between Receiver/Relative Operating Characteristics Display, Binomial, Logit, and Bayes' Rule Probability of Detection Methodologies

    Generazio, Edward R.

    2014-01-01

    Unknown risks are introduced into failure critical systems when probability of detection (POD) capabilities are accepted without a complete understanding of the statistical method applied and the interpretation of the statistical results. The presence of this risk in the nondestructive evaluation (NDE) community is revealed in common statements about POD. These statements are often interpreted in a variety of ways and therefore, the very existence of the statements identifies the need for a more comprehensive understanding of POD methodologies. Statistical methodologies have data requirements to be met, procedures to be followed, and requirements for validation or demonstration of adequacy of the POD estimates. Risks are further enhanced due to the wide range of statistical methodologies used for determining the POD capability. Receiver/Relative Operating Characteristics (ROC) Display, simple binomial, logistic regression, and Bayes' rule POD methodologies are widely used in determining POD capability. This work focuses on Hit-Miss data to reveal the framework of the interrelationships between Receiver/Relative Operating Characteristics Display, simple binomial, logistic regression, and Bayes' Rule methodologies as they are applied to POD. Knowledge of these interrelationships leads to an intuitive and global understanding of the statistical data, procedural and validation requirements for establishing credible POD estimates.

  20. Effect of crystal shape, size and reflector type on operation characteristics of gamma-radiation detectors based on CsI(Tl) and CsI(Na) scintillators

    Globus, M.E.; Grinyov, B.V.; Ratner, M.A.

    1996-01-01

    Operation characteristics of CsI(Tl) and CsI(Na) scintillation detectors, to a large degree connected with light collection in crystals, are calculated for various shapes, sizes and reflecting surface types. Allowance is made for the true light reflection indicatrix which is characterized by the effective mirror constituent of the reflected light, p. Its value , averaged over incidence angle, is used for the classification of reflecting surfaces. Operation characteristics (in particular, spectrometric ones) are found to be essentially dependent on . Tables of operation characteristics, given below, permit one to make inferential conclusions on an optimal combination of the shape, sizes an the reflecting surface version

  1. Stable Operation and Electricity Generating Characteristics of a Single-Cylinder Free Piston Engine Linear Generator: Simulation and Experiments

    Huihua Feng

    2015-01-01

    Full Text Available We present a novel design of a single-cylinder free piston engine linear generator (FPELG incorporating a linear motor as a rebound device. A systematic simulation model of this FPELG system was built containing a kinematic and dynamic model of the piston and mover, a magneto-electric model of the linear generator, a thermodynamic model of the single-cylinder engine, and a friction model between the piston ring and cylinder liner. Simulations were performed to understand the relationships between pre-set motor parameters and the running performance of the FPELG. From the simulation results, it was found that a motor rebound force with a parabolic profile had clear advantages over a force with a triangular profile, such as a higher running frequency and peak cylinder pressure, faster piston motion, etc. The rebound position and the amplitude of rebound force were also determined by simulations. The energy conversion characteristics of the generator were obtained from our FPELG test rig. The parameters of intake pressure, motor frequency, and load resistance were varied over certain ranges, and relationships among these three parameters were obtained. The electricity-generating characteristic parameters include output power and system efficiency, which can measure the quality of matching the controllable parameters. The output power can reach 25.9 W and the system efficiency can reach 13.7%. The results in terms of matching parameters and electricity-generating characteristics should be useful to future research in adapting these engines to various operating modes.

  2. Experimental Design and Data Analysis in Receiver Operating Characteristic Studies: Lessons Learned from Reports in Radiology from 1997 to 20061

    Shiraishi, Junji; Pesce, Lorenzo L.; Metz, Charles E.; Doi, Kunio

    2009-01-01

    Purpose: To provide a broad perspective concerning the recent use of receiver operating characteristic (ROC) analysis in medical imaging by reviewing ROC studies published in Radiology between 1997 and 2006 for experimental design, imaging modality, medical condition, and ROC paradigm. Materials and Methods: Two hundred ninety-five studies were obtained by conducting a literature search with PubMed with two criteria: publication in Radiology between 1997 and 2006 and occurrence of the phrase “receiver operating characteristic.” Studies returned by the query that were not diagnostic imaging procedure performance evaluations were excluded. Characteristics of the remaining studies were tabulated. Results: Two hundred thirty-three (79.0%) of the 295 studies reported findings based on observers' diagnostic judgments or objective measurements. Forty-three (14.6%) did not include human observers, with most of these reporting an evaluation of a computer-aided diagnosis system or functional data obtained with computed tomography (CT) or magnetic resonance (MR) imaging. The remaining 19 (6.4%) studies were classified as reviews or meta-analyses and were excluded from our subsequent analysis. Among the various imaging modalities, MR imaging (46.0%) and CT (25.7%) were investigated most frequently. Approximately 60% (144 of 233) of ROC studies with human observers published in Radiology included three or fewer observers. Conclusion: ROC analysis is widely used in radiologic research, confirming its fundamental role in assessing diagnostic performance. However, the ROC studies reported in Radiology were not always adequate to support clear and clinically relevant conclusions. © RSNA, 2009 Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.2533081632/-/DC1 PMID:19864510

  3. Assessment of thermal-hydraulic aging characteristics of Wolsong-1 and aging predictions to ensure optimized future operation

    Choi, H.; Hartmann, W.J.; Seo, H.B.

    2005-01-01

    'Full text:' All industrial plants undergo changes with time and nuclear plants are no exception. Wolsong-1 started its' commercial operation in 1983. Through more than 20 years of operation the plant has experienced aging behavior in many aspects. Specifically, aging of Primary Heat Transport System (PHTS), can affect fuel cooling characteristics. This reduces the margin to Onset of Intermittent Dryout (OID) of the CANDU fuel, a criterion used to conservatively prevent the possibility of fuel failure under nominal and accident scenarios. The power level associated with OID defines the Critical Channel Powers (CCP). In order to mitigate margin degradation Wolsong-1 had cleaned the primary side of all steam generators in March of 2003, reducing reactor inlet header temperature. However, even with this action, degradation of margin is continuing. To track and assess the current conditions of the primary heat transport system components, data showing aging effects are acquired and steady-state thermal-hydraulic models are developed. The resulting analysis allows for optimum safe and economic reactor operation. The following issues are explored specifically with respect to Wolsong-1 nuclear reactor operation. 1. Pressure tube creep measurement, prediction, and model development Radiation induced, increasing pressure tube diameters, specifically pressure tube diametral creep, cause more and more coolant to bypass the sub-channels of the fuel bundles, reducing margin to CCP. For Wolsong-1, pressure tubes were inspected in 1990, 1992, 1994, 2001 and 2004. Measurement in the nineties was done with the 'CIGAR' system and in the 21st century with the 'AFCIS' system. For each year's inspection, more than 12 channels are measured and some channels have been inspected in several years. The diameters of specific channels, repeatedly measured in more than three different years, allow an accurate diametral creep prediction. The initial manufacturing diameter and the aged, measured

  4. Performance and emission characteristics of a DI compression ignition engine operated on Honge, Jatropha and sesame oil methyl esters

    Banapurmath, N.R.; Tewari, P.G. [Department of Mechanical Engineering, B.V.B. College of Engineering and Technology, Vidyanagar, Poona-Bangalore Road, Hubli 580031 (India); Hosmath, R.S. [Department of Mechanical Engineering, K.L.E' s C.E.T., Belgaum (India)

    2008-09-15

    The high viscosity of vegetable oils leads to problem in pumping and spray characteristics. The inefficient mixing of vegetable oils with air contributes to incomplete combustion. The best way to use vegetable oils as fuel in compression ignition (CI) engines is to convert it into biodiesel. Biodiesel is a methyl or ethyl ester of fatty acids made from vegetable oils (both edible and non-edible) and animal fat. The main resources for biodiesel production can be non-edible oils obtained from plant species such as Pongamia pinnata (Honge oil), Jatropha curcas (Ratanjyot), Hevea brasiliensis (Rubber) and Calophyllum inophyllum (Nagchampa). Biodiesel can be used in its pure form or can be blended with diesel to form different blends. It can be used in CI engines with very little or no engine modifications. This is because it has properties similar to mineral diesel. This paper presents the results of investigations carried out on a single-cylinder, four-stroke, direct-injection, CI engine operated with methyl esters of Honge oil, Jatropha oil and sesame oil. Comparative measures of brake thermal efficiency, smoke opacity, HC, CO, NO{sub X}, ignition delay, combustion duration and heat release rates have been presented and discussed. Engine performance in terms of higher brake thermal efficiency and lower emissions (HC, CO, NO{sub X}) with sesame oil methyl ester operation was observed compared to methyl esters of Honge and Jatropha oil operation. (author)

  5. Hazardous Waste Management System - Identification and Listing of Hazardous Waste - Toxicity Characteristic - Hydrocarbon Recovery Operations - Federal Register Notice, April 2, 1991

    Proposal to extend the compliance date for the Toxicity Characteristic until January 25, 1993 for produced groundwater from free phase hydrocarbon recovery operations at certain petroleum industry sites-namely, refineries, marketing terminals, bulk plants.

  6. Hazardous Waste Management System - Identification and Listing of Hazardous Waste - Toxicity Characteristic - Hydrocarbon Recovery Operations - Federal Register Notice, October 5, 1990

    The Agency is promulgating an interim final rule to extend the compliance date of the Toxicity Characteristic rule for petroleum refining facilities, marketing terminals and bulk plants engaged in the recovery and remediation operation for 120 days.

  7. Hazardous Waste Management System - Identification and Listing of Hazardous Waste - Toxicity Characteristic - Hydrocarbon Recovery Operations - Federal Register Notice, February 1, 1991

    Extends the compliance date of the Toxicity Characteristic until January 25, 1991 for groundwater that is reinjected or reinfiltrated during existing hydrocarbon recovery operations at petroleum refineries, marketing terminals, and bulk plants.

  8. Improvement in operational characteristics of KEPCO’s line-commutation-type superconducting hybrid fault current limiter

    Yim, S.-W.; Park, B.-C.; Jeong, Y.-T.; Kim, Y.-J.; Yang, S.-E.; Kim, W.-S.; Kim, H.-R.; Du, H.-I.

    2013-01-01

    Highlights: ► A line-commutation type hybrid FCL was modified for 1st peak current limitation. ► A superconducting module of current limitation and fault detection was fabricated. ► The superconducting module was applied to a hybrid FCL system and tested. ► 7.4 kA p fault current was limited to 4.3 kA p at the first-half cycle by the FCL. -- Abstract: A 22.9 kV class hybrid fault current limiter (FCL) developed by Korea Electric Power Corporation and LS Industrial Systems in 2006 operates using the line commutation mechanism and begins to limit the fault current after the first half-cycle. The first peak of the fault current is available for protective coordination in the power system. However, it also produces a large electromagnetic force and imposes a huge stress on power facilities such as the main transformer and gas-insulated switchgear. In this study, we improved the operational characteristics of the hybrid FCL in order to reduce the first peak of the fault current. While maintaining the structure of the hybrid FCL system, we developed a superconducting module that detects and limits the fault current during the first half-cycle. To maintain the protective coordination capacity, the hybrid FCL was designed to reduce the first peak value of the fault current by up to approximately 30%. The superconducting module was also designed to produce a minimum AC loss, generating a small, uniform magnetic field distribution during normal operation. Performance tests confirmed that when applied to the hybrid FCL, the superconducting module showed successful current limiting operation without any damage

  9. Receiver operating characteristic analysis and its potential role in evaluating the effect of head movement in PET of the brain

    Patterson, H.; Clarke, G.H.; Lombardo, P.; McKay, W.J.; Austin and Repatriation Medical Centre, Heidelberg, VIC

    1999-01-01

    Full text: We outline an example of receiver operating characteristic (ROC) analysis in the assessment of image quality. ROC analysis is a measure of image quality that accounts for the consequences of the decision and the role of the observer. Kim and Haynie (Nuclear Diagnostic Imaging: Practical Clinical Applications. Melbourne: Macmillan, 1987) describe ROC analysis as an 'objective approach to the evaluation of diagnostic decision making'. ROC analysis is an ideal technique for evaluating images of a Hoffman brain phantom obtained using positron emission tomography. Images have been acquired with the phantom in different positions. The position of the phantom and the time the phantom remained in each position was based on the measurements of head movement during simulated brain imaging (Patterson et al., Technologists Symposium, ANZSNM, 1998). This study was undertaken to explore the potential of ROC analysis in determining the effect of movement on the ability to detect lesions of various sizes

  10. A Primer on Receiver Operating Characteristic Analysis and Diagnostic Efficiency Statistics for Pediatric Psychology: We Are Ready to ROC

    2014-01-01

    Objective To offer a practical demonstration of receiver operating characteristic (ROC) analyses, diagnostic efficiency statistics, and their application to clinical decision making using a popular parent checklist to assess for potential mood disorder. Method Secondary analyses of data from 589 families seeking outpatient mental health services, completing the Child Behavior Checklist and semi-structured diagnostic interviews. Results Internalizing Problems raw scores discriminated mood disorders significantly better than did age- and gender-normed T scores, or an Affective Problems score. Internalizing scores 30 had a diagnostic likelihood ratio of 7.4. Conclusions This study illustrates a series of steps in defining a clinical problem, operationalizing it, selecting a valid study design, and using ROC analyses to generate statistics that support clinical decisions. The ROC framework offers important advantages for clinical interpretation. Appendices include sample scripts using SPSS and R to check assumptions and conduct ROC analyses. PMID:23965298

  11. Maximum likelihood estimation of dose-response parameters for therapeutic operating characteristic (TOC) analysis of carcinoma of the nasopharynx

    Metz, C.E.; Tokars, R.P.; Kronman, H.B.; Griem, M.L.

    1982-01-01

    A Therapeutic Operating Characteristic (TOC) curve for radiation therapy plots, for all possible treatment doses, the probability of tumor ablation as a function of the probability of radiation-induced complication. Application of this analysis to actual therapeutic situation requires that dose-response curves for ablation and for complication be estimated from clinical data. We describe an approach in which ''maximum likelihood estimates'' of these dose-response curves are made, and we apply this approach to data collected on responses to radiotherapy for carcinoma of the nasopharynx. TOC curves constructed from the estimated dose-response curves are subject to moderately large uncertainties because of the limitations of available data.These TOC curves suggest, however, that treatment doses greater than 1800 rem may substantially increase the probability of tumor ablation with little increase in the risk of radiation-induced cervical myelopathy, especially for T1 and T2 tumors

  12. Verification of a model for the detection of intrauterine growth restriction (IUGR) by receiver operating characteristics (ROC)

    Liu, Pengbo; Mongelli, Max; Mondry, Adrian

    2004-07-01

    The purpose of this study is to verify by Receiver Operating Characteristics (ROC) a mathematical model supporting the hypothesis that IUGR can be diagnosed by estimating growth velocity. The ROC compare computerized simulation results with clinical data from 325 pregnant British women. Each patient had 6 consecutive ultrasound examinations for fetal abdominal circumference (fac). Customized and un-customized fetal weights were calculated according to Hadlock"s formula. IUGR was diagnosed by the clinical standard, i.e. estimated weight below the tenth percentile. Growth velocity was estimated by calculating the changes of fac (Dzfac/dt) at various time intervals from 3 to 10 weeks. Finally, ROC was used to compare the methods. At 3~4 weeks scan interval, the area under the ROC curve is 0.68 for customized data and 0.66 for the uncustomized data with 95% confidence interval. Comparison between simulation data and real pregnancies verified that the model is clinically acceptable.

  13. Multi-objective analysis of impacts of distributed generation placement on the operational characteristics of networks for distribution system planning

    Barin, Alexandre; Pozzatti, Luis F.; Canha, Luciane N.; Abaide, Alzenira R. [Federal University of Santa Maria - UFSM, Post-graduation Program of Electric Engineering - PPGEE, Center of Studies of Energy and Environment - CEEMA, Santa Maria, RS (Brazil); Machado, Ricardo Q. [University of Sao Paulo - USP, Sao Carlos, SP (Brazil); Arend, Gustavo [State Electric Energy Company - CEEE-D, Division of Distribution, Porto Alegre, RS (Brazil)

    2010-12-15

    Recent advances in energy technology generation and new directions in electricity regulation have made distributed generation (DG) more widespread, with consequent significant impacts on the operational characteristics of distribution networks. For this reason, new methods for identifying such impacts are needed, together with research and development of new tools and resources to maintain and facilitate continued expansion towards DG. This paper presents a study aimed at determining appropriate DG sites for distribution systems. The main considerations which determine DG sites are also presented, together with an account of the advantages gained from correct DG placement. The paper intends to define some quantitative and qualitative parameters evaluated by Digsilent registered, GARP3 registered and DSA-GD software. A multi-objective approach based on the Bellman-Zadeh algorithm and fuzzy logic is used to determine appropriate DG sites. The study also aims to find acceptable DG locations both for distribution system feeders, as well as for nodes inside a given feeder. (author)

  14. Strengthening health security at the Hajj mass gatherings: characteristics of the infectious diseases surveillance systems operational during the 2015 Hajj.

    Alotaibi, Badriah M; Yezli, Saber; Bin Saeed, Abdul-Aziz A; Turkestani, Abdulhafeez; Alawam, Amnah H; Bieh, Kingsley L

    2017-05-01

    Hajj is one of the largest and the most ethnically and culturally diverse mass gatherings worldwide. The use of appropriate surveillance systems ensures timely information management for effective planning and response to infectious diseases threats during the pilgrimage. The literature describes infectious diseases prevention and control strategies for Hajj but with limited information on the operations and characteristics of the existing Hajj infectious diseases surveillance systems. We reviewed documents, including guidelines and reports from the Saudi Ministry of Health's database, to describe the characteristics of the infectious diseases surveillance systems that were operational during the 2015 Hajj, highlighting best practices and gaps and proposing strategies for strengthening and improvement. Using Pubmed and Embase online search engines and a combination of search terms including, 'mass gatherings' 'Olympics' 'surveillance' 'Hajj' 'health security', we explored the existing literature and highlighted some lessons learnt from other international mass gatherings. A regular indicator-based infectious disease surveillance system generates routine reports from health facilities within the Kingdom to the regional and central public health directorates all year round. During Hajj, enhanced indicator-based notifiable diseases surveillance systems complement the existing surveillance tool to ensure timely reporting of event information for appropriate action by public health officials. There is need to integrate the existing Hajj surveillance data management systems and to implement syndromic surveillance as an early warning system for infectious disease control during Hajj. International engagement is important to strengthen Hajj infectious diseases surveillance and to prevent disease transmission and globalization of infectious agents which could undermine global health security. © International Society of Travel Medicine, 2017. Published by Oxford University

  15. Reactor core T-H characteristics determination in case of parallel operation of different fuel assembly types

    Hermansky, J.; Petenyi, V.; Zavodsky, M.

    2009-01-01

    The WWER-440 nuclear fuel vendor permanently improve the assortment of produced nuclear fuel assemblies for achieving better fuel cycle economy and reactor operation safety. Therefore it is necessary to have the skilled methodology and computing code for analyzing factors which affecting the accuracy of flow redistributed determination through reactor on flows through separate parts of reactor core in case of parallel operation different assembly types. Whereas the geometric parameters of new manufactured assemblies were changed recently, the calculated flows through the fuel parts of different type of assemblies are depended also on their real position in reactor core. Therefore the computing code CORFLO was developed in VUJE Trnava for carrying out stationary analyses of T-H characteristics of reactor core within 60 deg symmetry. The CORFLO code deals the area of the active core which consists of 312 fuel assemblies and 37 control assemblies. Regarding the rotational 60 deg symmetry of reactor core only 1/6 of reactor core with 59 fuel assemblies is calculated. Computing code is verified and validated at this time. Paper presents the short description of computing code CORFLO with some calculated results. (Authors)

  16. [Development characteristics of aquatic plants in a constructed wetland for treating urban drinking water source at its initial operation stage].

    Zheng, Jun; Ma, Xin-Tang; Zhou, Lan; Zhou, Qing-Yuan; Wang, Zhong-Qiong; Wang, Wei-Dong; Yin, Cheng-Qing

    2011-08-01

    The development characteristics and improvement measures of aquatic plants were studied in Shijiuyang Constructed Wetland (SCW) at its initial operation stage. SCW was a large-scale wetland aiming to help relieve the source water pollution in Jiaxing City. A checklist of vascular plants in SCW was built, and species composition, life forms, biomass and association distributions were examined. Our objectives were to examine the diversity and community structure of aquatic plants in SCW at its initial operation stage, and to find out the possible hydrophyte improvement measures. The survey results showed that there were 49 vascular plant species belonging to 41 genera, 25 families in SCW, which greatly exceeded the artificially transplanted 13 species. The life forms of present aquatic plants in SCW were dominated by hygrophilous plants (20 species) and emerged plants (17 species), which accounted for 75.5% of the total number of aquatic plants. The aquatic plants transplanted artificially were dominated by emerged plants (accounted for 69.2%), while those naturally developed were predominated by hygrophilous plants (accounted for 47.2%). The horizontal distribution of aquatic plant community in SCW was mixed in the form of mosaics, which made up typical association complex. Except association Aeschynomene indica L., the dominant species of other associations were all those transplanted artificially. The naturally grown species scattered throughout the SCW and only occupied a small percentage. A marked difference was detected on the species and species richness of aquatic plants in different regions of SCW. Biomass of aquatic plant associations in SCW was 167.7 t. SCW has shown a trend of succession heading for quick increase of plant diversity at the primary operation stage. This trend provides a good material base for the future stable community of aquatic plants in SCW. According to the current status of aquatic plants, some suggestions were put forward on the

  17. The effects of urban driving conditions on the operating characteristics of conventional and hybrid electric city buses

    Soylu, Seref

    2014-01-01

    Highlights: • Operating characteristics of conventional and hybrid electric buses were examined. • Recovery of braking energy offers an excellent opportunity to improve fuel economy. • Speed and altitude profiles of routes have dramatic impacts on the energy recovery. • Capacity of the auxiliary power source has a dramatic impact on the energy recovery. • Round-trip efficiency of the regenerative braking system was calculated to be 27%. - Abstract: The basic operating characteristics of a conventional bus (CB) and a hybrid electric bus (HEB) were examined under urban driving conditions. To perform this examination, real-time operating data from the buses were collected on the Campus-Return route of the Sakarya Municipality. The main characteristics examined were the traction, braking, engine, engine generator unit (EGU), motor/generator (M/G), and ultracapacitor (Ucap) energies and efficiencies of the buses. The route elevation profile and the frequency of stop-and-go operations of the buses were found to have dramatic impacts on the braking and traction energies of the buses. The declining profile of the Campus-Return route provided an excellent opportunity for energy recovery by the regenerative braking system of the HEB. However, owing to the limits on the capacities and efficiencies of the hybrid drive train components and the Ucap, the bus braking energies were not recovered completely. Braking energies as high as 2.2 kW h per micro-trip were observed, but less than 1 kW h of braking energy per micro-trip was converted to electricity by the M/G; the rest of the braking energy was wasted in frictional braking. The maximum energy recovered and stored in the Ucap per micro-trip was 0.5 kW h, but the amount of energy recovered and stored per micro-trip was typically less than 0.2 kW h for the entire route. The cumulative braking energy recovered and stored in the Ucap for the Campus-Return route was 52% of the available brake energy, which was 13.02 kW h

  18. Association of prospective lower extremity musculoskeletal injury and musculoskeletal, balance, and physiological characteristics in Special Operations Forces.

    Keenan, Karen A; Wohleber, Meleesa F; Perlsweig, Katherine A; Baldwin, Thomas M; Caviston, Michael; Lovalekar, Mita; Connaboy, Christopher; Nindl, Bradley C; Beals, Kim

    2017-11-01

    Previous research has examined lower extremity (LE) musculoskeletal injury (MSI) patterns and risk factors in Special Operations Forces (SOF) trainees, conventional military personnel, and athletes; however, it is unclear if SOF have the same patterns/risk factors. This study aimed to determine the association of musculoskeletal, balance, and physiological characteristics with LE MSI in SOF. Cohort study. A total of 726 Air Force (N=140), Navy Sea, Air, and Land (N=301), and Special Warfare Combatant Crewmen (N=285) SOF (age=25.72±4.77years, height=178.34±6.63cm, weight=84.28±9.03kg) participated in laboratory testing, including: LE muscular strength and flexibility; balance; body composition; anaerobic power/capacity; and aerobic capacity. Medical charts were reviewed for LE MSI 365days following laboratory testing. Participants were assigned by injury status and laboratory data stratified by tertile. Chi-square statistics were calculated to determine the frequency of LE MSI across tertiles for each characteristic. There was a significant association between LE MSI and: ankle inversion strength (weaker side: Χ(2)=17.703; stronger side: Χ(2)=18.911; p≤0.001); ankle eversion/inversion strength ratio (lower side: Χ(2)=13.456; higher side: Χ(2)=16.885; p≤0.001); hamstring flexibility (less flexible: Χ(2)=19.930; more flexible Χ(2)=15.185; p≤0.001); gastrocnemius-soleus flexibility (less flexible: Χ(2)=7.889, p=0.019); dynamic balance asymmetry (Χ(2)=7.444, p=0.024); Vestibular and Preference ratios (Χ(2)=9.124, p=0.010 and Χ(2)=6.572, p=0.037, respectively); and aerobic capacity (Χ(2)=13.935, p=0.001). Characteristics associated with LE MSI are unique in SOF. Human performance program initiatives should include efforts to optimize ankle strength and flexibility, maintain moderate hamstring flexibility, expand dynamic balance strategies, and maximize aerobic capacity to reduce LE MSI risk. Copyright © 2017 Sports Medicine Australia. All rights

  19. Outcomes of PCI in Relation to Procedural Characteristics and Operator Volumes in the United States.

    Fanaroff, Alexander C; Zakroysky, Pearl; Dai, David; Wojdyla, Daniel; Sherwood, Matthew W; Roe, Matthew T; Wang, Tracy Y; Peterson, Eric D; Gurm, Hitinder S; Cohen, Mauricio G; Messenger, John C; Rao, Sunil V

    2017-06-20

    Professional guidelines have reduced the recommended minimum number to an average of 50 percutaneous coronary intervention (PCI) procedures performed annually by each operator. Operator volume patterns and associated outcomes since this change are unknown. The authors describe herein PCI operator procedure volumes; characteristics of low-, intermediate-, and high-volume operators; and the relationship between operator volume and clinical outcomes in a large, contemporary, nationwide sample. Using data from the National Cardiovascular Data Registry collected between July 1, 2009, and March 31, 2015, we examined operator annual PCI volume. We divided operators into low- (100 PCIs per year) volume groups, and determined the adjusted association between annual PCI volume and in-hospital outcomes, including mortality. The median annual number of procedures performed per operator was 59; 44% of operators performed PCI procedures per year. Low-volume operators more frequently performed emergency and primary PCI procedures and practiced at hospitals with lower annual PCI volumes. Unadjusted in-hospital mortality was 1.86% for low-volume operators, 1.73% for intermediate-volume operators, and 1.48% for high-volume operators. The adjusted risk of in-hospital mortality was higher for PCI procedures performed by low- and intermediate-volume operators compared with those performed by high-volume operators (adjusted odds ratio: 1.16 for low versus high; adjusted odds ratio: 1.05 for intermediate vs. high volume) as was the risk for new dialysis post PCI. No volume relationship was observed for post-PCI bleeding. Many PCI operators in the United States are performing fewer than the recommended number of PCI procedures annually. Although absolute risk differences are small and may be partially explained by unmeasured differences in case mix between operators, there remains an inverse relationship between PCI operator volume and in-hospital mortality that persisted in risk

  20. Scene perception and memory revealed by eye movements and receiver-operating characteristic analyses: does a cultural difference truly exist?

    Evans, Kris; Rotello, Caren M; Li, Xingshan; Rayner, Keith

    2009-02-01

    Cultural differences have been observed in scene perception and memory: Chinese participants purportedly attend to the background information more than did American participants. We investigated the influence of culture by recording eye movements during scene perception and while participants made recognition memory judgements. Real-world pictures with a focal object on a background were shown to both American and Chinese participants while their eye movements were recorded. Later, memory for the focal object in each scene was tested, and the relationship between the focal object (studied, new) and the background context (studied, new) was manipulated. Receiver-operating characteristic (ROC) curves show that both sensitivity and response bias were changed when objects were tested in new contexts. However, neither the decrease in accuracy nor the response bias shift differed with culture. The eye movement patterns were also similar across cultural groups. Both groups made longer and more fixations on the focal objects than on the contexts. The similarity of eye movement patterns and recognition memory behaviour suggests that both Americans and Chinese use the same strategies in scene perception and memory.

  1. Effect of operating parameters and membrane characteristics on air gap membrane distillation performance for the treatment of highly saline water

    Xu, Jingli

    2016-04-07

    In this study, ten different commercially available PTFE, PP and PVDF membranes were tested in desalination of highly saline water by air gap membrane distillation (AGMD). Process performance was investigated under different operating parameters, such as feed temperatures, feed flow velocities and salt concentrations reaching 120 g/L, and different membrane characteristics, such as membrane material, thickness, pore size and support layer, using a locally designed and fabricatd AGMD module and spacer. Results showed that increasing feed temperature increases permeate flux regardless of the feed concentration. However, feed flow velocity does not significantly affect the flux, especially at low feed temperatures. The PP membrane showed a better performance than the PVDF and PTFE membranes. Permeate flux decreases with the increase of salt concentration of feed solution, especially at higher concentrations above 90 g/L. The existence of membrane support layer led to a slight decrease of permeate flux. Membranes with pore sizes of 0.2 and 0.45 μm gave the best performance. Smaller pore size led to lower flux and larger pore size led to pore wetting due to lower LEP values. The effect of concentration polarization and temperature polarization has also been studied and compared.

  2. Current sheet characteristics of a parallel-plate electromagnetic plasma accelerator operated in gas-prefilled mode

    Liu, Shuai; Huang, Yizhi; Guo, Haishan; Lin, Tianyu; Huang, Dong; Yang, Lanjun

    2018-05-01

    The axial characteristics of a current sheet in a parallel-plate electromagnetic plasma accelerator operated in gas-prefilled mode are reported. The accelerator is powered by a fourteen stage pulse forming network. The capacitor and inductor in each stage are 1.5 μF and 300 nH, respectively, and yield a damped oscillation square wave of current with a pulse width of 20.6 μs. Magnetic probes and photodiodes are placed at various axial positions to measure the behavior of the current sheet. Both magnetic probe and photodiode signals reveal a secondary breakdown when the current reverses the direction. An increase in the discharge current amplitude and a decrease in pressure lead to a decrease in the current shedding factor. The current sheet velocity and thickness are nearly constant during the run-down phase under the first half-period of the current. The current sheet thicknesses are typically in the range of 25 mm to 40 mm. The current sheet velocities are in the range of 10 km/s to 45 km/s when the discharge current is between 10 kA and 55 kA and the gas prefill pressure is between 30 Pa and 800 Pa. The experimental velocities are about 75% to 90% of the theoretical velocities calculated with the current shedding factor. One reason for this could be that the idealized snowplow analysis model ignores the surface drag force.

  3. Clinical diagnostic accuracy of acute colonic diverticulitis in patients admitted with acute abdominal pain, a receiver operating characteristic curve analysis.

    Jamal Talabani, A; Endreseth, B H; Lydersen, S; Edna, T-H

    2017-01-01

    The study investigated the capability of clinical findings, temperature, C-reactive protein (CRP), and white blood cell (WBC) count to discern patients with acute colonic diverticulitis from all other patients admitted with acute abdominal pain. The probability of acute diverticulitis was assessed by the examining doctor, using a scale from 0 (zero probability) to 10 (100 % probability). Receiver operating characteristic (ROC) curves were used to assess the clinical diagnostic accuracy of acute colonic diverticulitis in patients admitted with acute abdominal pain. Of 833 patients admitted with acute abdominal pain, 95 had acute colonic diverticulitis. ROC curve analysis gave an area under the ROC curve (AUC) of 0.95 (CI 0.92 to 0.97) for ages patients. Separate analysis showed an AUC = 0.83 (CI 0.80 to 0.86) of CRP alone. White blood cell count and temperature were almost useless to discriminate acute colonic diverticulitis from other types of acute abdominal pain, AUC = 0.59 (CI 0.53 to 0.65) for white blood cell count and AUC = 0.57 (0.50 to 0.63) for temperature, respectively. This prospective study demonstrates that standard clinical evaluation by non-specialist doctors based on history, physical examination, and initial blood tests on admission provides a high degree of diagnostic precision in patients with acute colonic diverticulitis.

  4. The effects of fuel characteristics and engine operating conditions on the elemental composition of emissions from heavy duty diesel buses

    M.C.H. Lim; G.A. Ayoko; L. Morawska; Z.D. Ristovski; E.R. Jayaratne [Queensland University of Technology, Brisbane, Qld. (Australia). International Laboratory for Air Quality and Health, School of Physical and Chemical Sciences

    2007-08-15

    The effects of fuel characteristics and engine operating conditions on elemental composition of emissions from twelve heavy duty diesel buses have been investigated. Two types of diesel fuels - low sulfur diesel (LSD) and ultra low sulfur diesel (ULSD) fuels with 500 ppm and 50 ppm sulfur contents respectively and 3 driving modes corresponding to 25%, 50% and 100% power were used. Elements present in the tailpipe emissions were quantified by inductively coupled plasma mass spectrometry (ICPMS) and those found in measurable quantities included Mg, Ca, Cr, Fe, Cu, Zn, Ti, Ni, Pb, Be, P, Se, Ti and Ge. Multivariate analyses using multi-criteria decision making methods (MCDM), principal component analysis (PCA) and partial least squares (PLS) facilitated the extraction of information about the structure of the data. MCDM showed that the emissions of the elements were strongly influenced by the engine driving conditions while the PCA loadings plots showed that the emission factors of the elements were correlated with those of other pollutants such as particle number, total suspended particles, CO, CO{sub 2} and NOx. Partial least square analysis revealed that the emission factors of the elements were strongly dependent on the fuel parameters such as the fuel sulfur content, fuel density, distillation point and cetane index. Strong correlations were also observed between these pollutants and the engine power or exhaust temperature. The study provides insights into the possible role of fuel sulfur content in the emission of inorganic elements from heavy duty diesel vehicles. 39 refs., 1 fig., 4 tabs.

  5. Operation characteristic analysis of a direct methanol fuel cell system using the methanol sensor-less control method

    Chen, C.Y.; Chang, C.L. [Institute of Nuclear Energy Research (INER), Longtan Township, Taoyuan County (China); Sung, C.C. [National Taiwan University (China)

    2012-10-15

    The application of methanol sensor-less control in a direct methanol fuel cell (DMFC) system eliminates most of the problems encountered when using a methanol sensor and is one of the major solutions currently used in commercial DMFCs. This study focuses on analyzing the effect of the operating characteristics of a DMFC system on its performance under the methanol sensor-less control as developed by Institute of Nuclear Energy Research (INER). Notably, the influence of the dispersion of the methanol injected on the behavior of the system is investigated systematically. In addition, the mechanism of the methanol sensor-less control is investigated by varying factors such as the timing of the injection of methanol, the cathode flow rate, and the anode inlet temperature. These results not only provide insight into the mechanism of methanol sensor-less control but can also aid in the improvement and application of DMFC systems in portable and low-power transportation. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. ROC [Receiver Operating Characteristics] study of maximum likelihood estimator human brain image reconstructions in PET [Positron Emission Tomography] clinical practice

    Llacer, J.; Veklerov, E.; Nolan, D.; Grafton, S.T.; Mazziotta, J.C.; Hawkins, R.A.; Hoh, C.K.; Hoffman, E.J.

    1990-10-01

    This paper will report on the progress to date in carrying out Receiver Operating Characteristics (ROC) studies comparing Maximum Likelihood Estimator (MLE) and Filtered Backprojection (FBP) reconstructions of normal and abnormal human brain PET data in a clinical setting. A previous statistical study of reconstructions of the Hoffman brain phantom with real data indicated that the pixel-to-pixel standard deviation in feasible MLE images is approximately proportional to the square root of the number of counts in a region, as opposed to a standard deviation which is high and largely independent of the number of counts in FBP. A preliminary ROC study carried out with 10 non-medical observers performing a relatively simple detectability task indicates that, for the majority of observers, lower standard deviation translates itself into a statistically significant detectability advantage in MLE reconstructions. The initial results of ongoing tests with four experienced neurologists/nuclear medicine physicians are presented. Normal cases of 18 F -- fluorodeoxyglucose (FDG) cerebral metabolism studies and abnormal cases in which a variety of lesions have been introduced into normal data sets have been evaluated. We report on the results of reading the reconstructions of 90 data sets, each corresponding to a single brain slice. It has become apparent that the design of the study based on reading single brain slices is too insensitive and we propose a variation based on reading three consecutive slices at a time, rating only the center slice. 9 refs., 2 figs., 1 tab

  7. Determination of the full characteristics of a journal bearing for a fast reactor sodium pump using a full scale model bearing operating in water

    Gilroy, J.E.; Dostal, M.; Jones, R.P.

    1988-01-01

    This paper describes the analytical and experimental work carried out in support of a sodium-lubricated hydrostatic bearing for the CDFR primary sodium pump. The principle objective of the work was to establish bearing characteristics under steady-state and transient running conditions. A knowledge of these characteristics is necessary for the determination of the dynamic performance of the pump under normal and transient operating conditions and also under earthquake loading conditions

  8. Identification of hazardous drinking with the Young Adult Alcohol Consequences Questionnaire: Relative operating characteristics as a function of gender.

    Read, Jennifer P; Haas, Amie L; Radomski, Sharon; Wickham, Robert E; Borish, Sarah E

    2016-10-01

    Heavy and problematic drinking is common on college campuses and is associated with myriad hazardous outcomes. The Young Adult Alcohol Consequences Questionnaire (YAACQ; Read et al., 2006) was developed to provide comprehensive and expedient assessment of negative consequences of young adult drinking and has been used in a number of research and clinical settings. To date, no empirically derived cutoffs for the YAACQ have been available for use in the identification of those drinkers at greatest risk. This was the objective of the present study. In a large (N = 1,311) and demographically heterogeneous multisite sample, we identified cutoff scores for the YAACQ, and the contrasted detection of hazardous drinking using these cutoffs with those recommended for the Alcohol Use Disorders Identification Test (AUDIT). We also examined whether cutoffs differed by gender. Results of receiver operating characteristic (ROC) analysis yielded cutoffs that delineate 3 levels (or zones) of hazardous drinking risk: low, moderate, and high. A cutoff of 8 differentiated those at low risk from those at moderate risk or greater, and a cutoff of 16 differentiated between moderate and high risk. These zones corresponded to other indices of risky drinking, including heavy episodic "binge" drinking, more frequent alcohol consumption, and engagement in alcohol risk behaviors. Scores differentiating low to moderate risk differed for men (8) and women (10), whereas the cutoff for high risk was the same (16) across the sexes. Findings suggest that the YAACQ can be used to reliably assess level of drinking risk among college students. Furthermore, these cut scores may be used to refer to interventions varying in intensity level, based on level of indicated alcohol risk. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  9. Critical thresholds of liver function parameters for ketosis prediction in dairy cows using receiver operating characteristic (ROC) analysis.

    Sun, Yuhang; Wang, Bo; Shu, Shi; Zhang, Hongyou; Xu, Chuang; Wu, Ling; Xia, Cheng

    2015-01-01

    Fatty liver syndrome and ketosis are important metabolic disorders in high-producing cows during early lactation with fatty liver usually preceding ketosis. To date, parameters for early prediction of the risk of ketosis have not been investigated in China. To determine the predictive value of some parameters on the risk of ketosis in China. In a descriptive study, 48 control and 32 ketotic Holstein Friesian cows were randomly selected from one farm with a serum β-hydroxybutyrate (BHBA) concentration of 1.20 mmol/L as cutoff point. The risk prediction thresholds for ketosis were determined by receiver operating characteristic (ROC) analysis. In line with a high BHBA concentration, blood glucose concentration was significantly lower in ketotic cows compared to control animals (2.77 ± 0.24 versus 3.34 ± 0.03 mmol/L; P = 0.02). Thresholds were more than 0.76 mmol/L for nonesterified fatty acids (NEFA, with 65% sensitivity and 92% specificity), more than 104 U/L for aspartate aminotransferase (AST, 74% and 85%, respectively), less than 140 U/L for cholinesterase (CHE, 75% and 59%, respectively), and more than 3.3 µmol/L for total bilirubin (TBIL, 58% and 83%, respectively). There were significant correlations between BHBA and glucose (R = -4.74), or CHE (R = -0.262), BHBA and NEFA (R = 0.520), or AST (R = 0.525), or TBIL (R = 0.278), or direct bilirubin (DBIL, R = 0.348). AST, CHE, TBIL and NEFA may be useful parameters for risk prediction of ketosis. This study might be of value in addressing novel directions for future research on the connection between ketosis and liver dysfunction.

  10. Receiver-operating characteristic curves for somatic cell scores and California mastitis test in Valle del Belice dairy sheep.

    Riggio, Valentina; Pesce, Lorenzo L; Morreale, Salvatore; Portolano, Baldassare

    2013-06-01

    Using receiver-operating characteristic (ROC) curve methodology this study was designed to assess the diagnostic effectiveness of somatic cell count (SCC) and the California mastitis test (CMT) in Valle del Belice sheep, and to propose and evaluate threshold values for those tests that would optimally discriminate between healthy and infected udders. Milk samples (n=1357) were collected from 684 sheep in four flocks. The prevalence of infection, as determined by positive bacterial culture was 0.36, 87.7% of which were minor and 12.3% major pathogens. Of the culture negative samples, 83.7% had an SCCculture negative vs. infected), minor pathogen status (culture negative vs. infected with minor pathogens), major pathogen status (culture negative vs. infected with major pathogens), and CMT results were evaluated, the estimated area under the ROC curve was greater for glands infected with major compared to minor pathogens (0.88 vs. 0.73), whereas the area under the curve considering all pathogens was similar to the one for minor pathogens (0.75). The estimated optimal thresholds were 3.00 (CMT), 2.81 (SCS for the whole sample), 2.81 (SCS for minor pathogens), and 3.33 (SCS for major pathogens). These correctly classified, respectively, 69.0%, 73.5%, 72.6% and 91.0% of infected udders in the samples. The CMT appeared only to discriminate udders infected with major pathogens. In this population, SCS appeared to be the best indirect test of the bacteriological status of the udder. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Study on the Operating Characteristics and System Modelling of Loop type Thermosyphon for Using Solar Thermal Energy

    Kang, Myeong Cheol

    1999-02-01

    Solar energy is one of the promising resources of renewable energy. It is of particular interest due to the energy shortage and environment pollution problems. Water heating by solar energy for domestic use is one of the most successful and feasible applications of solar energy. The thermosyphon SDHWS and the loop type thermosyphon systems are widely used for domestic hot water system. The loop type thermosyphon is a circulation device for transferring the heat produced at the evaporator area to the condenser area in the loop by a working fluid. The system has the advantage of high heat transfer rate. A phase change of the working fluid occurs at the evaporator section and the vapor is transported to the condenser by the density gradient. The loop type thermosyphon collector can be made of smaller area and has higher efficiency than the present thermosyphon SDHWS. In this study, the operating characteristics of various working fluids being used have been identified. The working fluids employed in the study were ethanol, water and a binary mixture of ethanol and water. The volume of working fluid used in this study were 30%, 40%, 50%, 60% and 70% of evaporator volume. An increased heat was applied with the increased volume of working fluid. It is observed that, in the thermosyphon with low volume of working fluid, such as 30% or 40%, the fluid was dried out. The average efficiency of the loop type thermosyphon was 46% with high solar irradiation and 43% with low irradiation. The flow pattern and mechanism of the heat transfer were identified through this study. Flow patterns of the binary mixture working fluid were also investigated, and the patterns were recorded in the camera. The system parameters were calculated using the thermal performance data. Modelling of the system was carried out using PSTAR method and TRNSYS program

  12. Receiver Operating Characteristic Curve-Based Prediction Model for Periodontal Disease Updated With the Calibrated Community Periodontal Index.

    Su, Chiu-Wen; Yen, Amy Ming-Fang; Lai, Hongmin; Chen, Hsiu-Hsi; Chen, Sam Li-Sheng

    2017-12-01

    The accuracy of a prediction model for periodontal disease using the community periodontal index (CPI) has been undertaken by using an area under a receiver operating characteristics (AUROC) curve. How the uncalibrated CPI, as measured by general dentists trained by periodontists in a large epidemiologic study, and affects the performance in a prediction model, has not been researched yet. A two-stage design was conducted by first proposing a validation study to calibrate CPI between a senior periodontal specialist and trained general dentists who measured CPIs in the main study of a nationwide survey. A Bayesian hierarchical logistic regression model was applied to estimate the non-updated and updated clinical weights used for building up risk scores. How the calibrated CPI affected performance of the updated prediction model was quantified by comparing AUROC curves between the original and updated models. Estimates regarding calibration of CPI obtained from the validation study were 66% and 85% for sensitivity and specificity, respectively. After updating, clinical weights of each predictor were inflated, and the risk score for the highest risk category was elevated from 434 to 630. Such an update improved the AUROC performance of the two corresponding prediction models from 62.6% (95% confidence interval [CI]: 61.7% to 63.6%) for the non-updated model to 68.9% (95% CI: 68.0% to 69.6%) for the updated one, reaching a statistically significant difference (P prediction model was demonstrated for periodontal disease as measured by the calibrated CPI derived from a large epidemiologic survey.

  13. Evaluation of operating characteristics for a chabazite zeolite system for treatment of process wastewater at Oak Ridge National Laboratory

    Kent, T.E.; Perona, J.J.; Jennings, H.L.; Lucero, A.J.; Taylor, P.A.

    1998-02-01

    Laboratory and pilot-scale testing were performed for development and design of a chabazite zeolite ion-exchange system to replace existing treatment systems at the Process Waste Treatment Plant (PWTP) at Oak Ridge National Laboratory (ORNL). The process wastewater treatment systems at ORNL need upgrading to improve efficiency, reduce waste generation, and remove greater quantities of contaminants from the wastewater. Previous study indicated that replacement of the existing PWTP systems with an ion-exchange system using chabazite zeolite will satisfy these upgrade objectives. Pilot-scale testing of the zeolite system was performed using a commercially available ion-exchange system to evaluate physical operating characteristics and to validate smaller-scale column test results. Results of this test program indicate that (1) spent zeolite can be sluiced easily and completely from a commercially designed vessel, (2) clarification followed by granular anthracite prefilters is adequate pretreatment for the zeolite system, and (3) the length of the mass transfer zone was comparable with that obtained in smaller-scale column tests. Laboratory studies were performed to determine the loading capacity of the zeolite for selected heavy metals. These test results indicated fairly effective removal of silver, cadmium, copper, mercury, nickel, lead, and zinc from simple water solutions. Heavy-metals data collected during pilot-scale testing of actual wastewater indicated marginal removal of iron, copper, and zinc. Reduced effectiveness for other heavy metals during pilot testing can be attributed to the presence of interfering cations and the relatively short zeolite/wastewater contact time. Flocculating agents (polyelectrolytes) were tested for pretreatment of wastewater prior to the zeolite flow-through column system. Several commercially available polyelectrolytes were effective in flocculation and settling of suspended solids in process wastewater

  14. Relationship between Grooming Performance and Motor and Cognitive Functions in Stroke Patients with Receiver Operating Characteristic Analysis.

    Fujita, Takaaki; Sato, Atsushi; Tsuchiya, Kenji; Ohashi, Takuro; Yamane, Kazuhiro; Yamamoto, Yuichi; Iokawa, Kazuaki; Ohira, Yoko; Otsuki, Koji; Tozato, Fusae

    2017-12-01

    This study aimed to elucidate the relationship between grooming performance of stroke patients and various motor and cognitive functions and to examine the cognitive and physical functional standards required for grooming independence. We retrospectively analyzed the data of 96 hospitalized patients with first stroke in a rehabilitation hospital ward. Logistic regression analysis and receiver operating characteristic curves were used to investigate the related cognitive and motor functions with grooming performance and to calculate the cutoff values for independence and supervision levels in grooming. For analysis between the independent and supervision-dependent groups, the only item with an area under the curve (AUC) of .9 or higher was the Berg Balance Scale, and the calculated cutoff value was 41/40 (sensitivity, 83.6%; specificity, 87.8%). For analysis between the independent-supervision and dependent groups, the items with an AUC of .9 or higher were the Simple Test for Evaluating Hand Function (STEF) on the nonaffected side, Vitality Index (VI), and FIM ® cognition. The cutoff values were 68/67 for the STEF (sensitivity, 100%; specificity, 72.2%), 9/8 points for the VI (sensitivity, 92.3%; specificity, 88.9%), and 23/22 points for FIM ® cognition (sensitivity, 91.0%; specificity, 88.9%). Our results suggest that upper-extremity functions on the nonaffected side, motivation, and cognitive functions are particularly important to achieve the supervision level and that balance is important to reach the independence level. The effective improvement of grooming performance is possible by performing therapeutic or compensatory intervention on functions that have not achieved these cutoff values. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  15. Predictive factors in patients with hepatocellular carcinoma receiving sorafenib therapy using time-dependent receiver operating characteristic analysis.

    Nishikawa, Hiroki; Nishijima, Norihiro; Enomoto, Hirayuki; Sakamoto, Azusa; Nasu, Akihiro; Komekado, Hideyuki; Nishimura, Takashi; Kita, Ryuichi; Kimura, Toru; Iijima, Hiroko; Nishiguchi, Shuhei; Osaki, Yukio

    2017-01-01

    To investigate variables before sorafenib therapy on the clinical outcomes in hepatocellular carcinoma (HCC) patients receiving sorafenib and to further assess and compare the predictive performance of continuous parameters using time-dependent receiver operating characteristics (ROC) analysis. A total of 225 HCC patients were analyzed. We retrospectively examined factors related to overall survival (OS) and progression free survival (PFS) using univariate and multivariate analyses. Subsequently, we performed time-dependent ROC analysis of continuous parameters which were significant in the multivariate analysis in terms of OS and PFS. Total sum of area under the ROC in all time points (defined as TAAT score) in each case was calculated. Our cohort included 175 male and 50 female patients (median age, 72 years) and included 158 Child-Pugh A and 67 Child-Pugh B patients. The median OS time was 0.68 years, while the median PFS time was 0.24 years. On multivariate analysis, gender, body mass index (BMI), Child-Pugh classification, extrahepatic metastases, tumor burden, aspartate aminotransferase (AST) and alpha-fetoprotein (AFP) were identified as significant predictors of OS and ECOG-performance status, Child-Pugh classification and extrahepatic metastases were identified as significant predictors of PFS. Among three continuous variables (i.e., BMI, AST and AFP), AFP had the highest TAAT score for the entire cohort. In subgroup analyses, AFP had the highest TAAT score except for Child-Pugh B and female among three continuous variables. In continuous variables, AFP could have higher predictive accuracy for survival in HCC patients undergoing sorafenib therapy.

  16. Evaluation of Landing Characteristics Achieved by Simulations and Flight Tests on a Small-scaled Model Related to Magnetically Levitated Advanced Take-off and Landing Operations

    Rohacs, D.; Voskuijl, M.; Siepenkotter, N.

    2014-01-01

    The goal of this paper is to simulate and measure on a small-scaled model the landing characteristics related to take-off and landing (TOL) operations supported by a magnetic levitation (MAGLEV) system as ground-based power supply. The technical feasibility and the potential benefits of using

  17. From Humans to Rats and Back Again: Bridging the Divide between Human and Animal Studies of Recognition Memory with Receiver Operating Characteristics

    Koen, Joshua D.; Yonelinas, Andrew P.

    2011-01-01

    Receiver operating characteristics (ROCs) have been used extensively to study the processes underlying human recognition memory, and this method has recently been applied in studies of rats. However, the extent to which the results from human and animal studies converge is neither entirely clear, nor is it known how the different methods used to…

  18. Summary receiver operating characteristic curves as a technique for meta-analysis of the diagnostic performance of duplex ultrasonography in peripheral arterial disease

    deVries, SO; Hunink, MGM; Polak, JF

    Rationale and Objectives. We summarized and compared the diagnostic performance of duplex and color-guided duplex ultrasonography in the evaluation of peripheral arterial disease. We present our research as an example of the use of summary receiver operating characteristic (ROC) curves in a

  19. A Longitudinal Examination of The Impact of Founding Owner Operator Characteristics on Nascent Venture Performance: Evidence from the Kauffman Firm Survey

    Augustine Y. Dzathor

    2013-07-01

    Full Text Available This study attempts to revive and clarify the debate on ‘the entrepreneurial man’. We longitudinally examined the effects of seven founding-owner-operator characteristics (prior industry experience, level of formal education, age, gender, ethnicity and time committed to business operations on nascent venture performance. Our results indicate that owner work experience, level of education and hours worked in the business have significant effect on nascent venture performance, while inadequate owner reputation and luck of ethnic social capital may negatively affect nascent venture performance. Our findings also suggest that characteristic of the ‘entrepreneurial man’ are dynamic and leans towards a temporal contingency model. Different entrepreneur characteristics seem to assume prominence in firm performance at different times in a nascent venture’s life trajectory.

  20. Office-Based vs Traditional Operating Room Management of Recurrent Respiratory Papillomatosis: Impact of Patient Characteristics and Disease Severity.

    Tatar, Emel Çadalli; Kupfer, Robbi A; Barry, Jonnae Y; Allen, Clint T; Merati, Albert L

    2017-01-01

    Management of recurrent respiratory papillomatosis (RRP) in adults has evolved to include office-based laser techniques. To determine whether demographic or disease characteristics differ between patients undergoing office-based (office group) vs traditional operating room (OR group) surgical approaches for RRP. This study was a medical record review of adult patients with RRP treated between January 2011 and September 2013 at a tertiary care center. Patients were divided into 2 groups according to the setting in which the patient had the most procedures during the past 2 years. Demographic and disease characteristics were compared between patients receiving predominantly office-based vs predominantly OR management. Of 57 patients (47 male and 10 female, with a mean [SD] age of 53.5 [16.4] years) treated during the 2-year period, 34 patients underwent predominantly office-based management and 23 patients underwent predominantly OR management. Sex, age, and weight were not statistically significantly different between the 2 groups. Patients in the OR group had a younger age at RRP diagnosis (mean [SD], 28.7 [22.0] years in the OR group and 45.5 [20.5] years in the office group), with a mean difference of 16.8 years (95% CI, -28.3 to -5.4 years). Patients in the OR group also had a significantly higher Derkay score (mean [SD], 15.1 [5.7] in the OR group and 10.7 [5.0] in the office group), with a mean difference of 4.4 (95% CI, 1.6-7.3). No statistically significant differences in comorbidities were observed between the 2 groups except for type 1 or 2 diabetes, which was more common in the OR group. There were 5 patients (22%) with diabetes in the OR group and 1 patient (3%) with diabetes in the office group, with a mean difference of 19% (95% CI, 2.7%-35%). In a subanalysis that excluded patients with juvenile-onset RRP, Derkay score (mean [SD], 13.9 [4.5] in the OR group and 10.8 [5.1] in the office group), with a mean difference of 3.1 (95% CI, 0.5-6.1), and the

  1. The Foundations of Operational Resilience Assessing the Ability to Operate in an Anti-Access/Area Denial (A2/AD) Environment: The Analytical Framework, Lexicon, and Characteristics of the Operational Resilience Analysis Model (ORAM)

    2016-07-07

    University , Maxwell Air Force Base, Alabama). He shaped the definition of operational resilience and, therefore, the resulting analytic framework with...of airbases: • Type A: Main Operating Base ( MOB ). A facility outside the United States and U.S. territories with permanently stationed operating... MOB . [JP 1-02, 2014] • Type C: Forward Operating Location (FOL). A forward operating base that is served by a less extensive support structure than

  2. Effect of operating parameters and membrane characteristics on air gap membrane distillation performance for the treatment of highly saline water

    Xu, Jingli; Singh, Yogesh Balwant; Amy, Gary L.; Ghaffour, NorEddine

    2016-01-01

    , such as feed temperatures, feed flow velocities and salt concentrations reaching 120 g/L, and different membrane characteristics, such as membrane material, thickness, pore size and support layer, using a locally designed and fabricatd AGMD module and spacer

  3. Performance Analysis of an Evaporator for a Diesel Engine–Organic Rankine Cycle (ORC) Combined System and Influence of Pressure Drop on the Diesel Engine Operating Characteristics

    Chen Bei; Hongguang Zhang; Fubin Yang; Songsong Song; Enhua Wang; Hao Liu; Ying Chang; Hongjin Wang; Kai Yang

    2015-01-01

    The main purpose of this research is to analyze the performance of an evaporator for the organic Rankine cycle (ORC) system and discuss the influence of the evaporator on the operating characteristics of diesel engine. A simulation model of fin-and-tube evaporator of the ORC system is established by using Fluent software. Then, the flow and heat transfer characteristics of the exhaust at the evaporator shell side are obtained, and then the performance of the fin-and-tube evaporator of the ORC...

  4. Operation characteristic and performance comparison of organic Rankine cycle (ORC) for low-grade waste heat using R245fa, R123 and their mixtures

    Feng, Yong-qiang; Hung, Tzu-Chen; He, Ya-Ling; Wang, Qian; Wang, Shuang; Li, Bing-xi; Lin, Jaw-Ren; Zhang, Wenping

    2017-01-01

    Highlights: • Experimental comparison using R123, R245fa and their mixtures has been investigated. • The basic operation parameters and the detailed operation characteristics of pure and mixture working fluids are addressed. • The mixture owns a relatively higher pump power consumption, 10–50% higher than that of R245fa and 2–47% higher than that of R123. • The highest system generating efficiency of 4.53% is obtained by 0.67R245fa/0.33R123. - Abstract: The operation characteristic and performance comparison of low-grade organic Rankine cycle (ORC) using R245fa, R123 and their mixtures have been investigated. The heat source temperature is set to be 120 °C, while the mass flow rate is controlled by adjusting the pump frequency. The basic operation parameters are first examined, while the detailed operation characteristics of pure and mixture working fluids are addressed. The system overall performance, including thermal efficiency and system generating efficiency, for pure and mixture working fluids are explored. The experimental results show that the mixtures own a relatively higher pump power consumption and enhancing the pump performance is also significant for ORC application. Whether the mixtures exhibit better thermodynamic performance than the pure working fluids depend on the operation parameters and mass fraction of mixtures. 0.67R245fa/0.33R123 owns the highest maximum net electricity output of 1.67 kW, 4.38% higher than that of R245fa and 63.73% higher than that of R123. Compared to the pure working fluids, the mixture working fluids own a better thermodynamic performance and a moderate economic performance.

  5. Influence of Actively Controlled Heat Release Timing on the Performance and Operational Characteristics of a Rotary Valve, Acoustically Resonant Pulse Combustor

    Lisanti, Joel; Roberts, William L.

    2017-01-01

    The influence of heat release timing on the performance and operational characteristics of a rotary valve, acoustically resonant pulse combustor is investigated both experimentally and numerically. Simulation results are obtained by solving the quasi-1D Navier-Stokes equations with forced volumetric heat addition. Experimental efforts modify heat release timing through modulated fuel injection and modification of the fluid dynamic mixing. Results indicate that the heat release timing has a profound effect on the operation and efficiency of the pulse combustor and that this timing can be difficult to control experimentally.

  6. Influence of Actively Controlled Heat Release Timing on the Performance and Operational Characteristics of a Rotary Valve, Acoustically Resonant Pulse Combustor

    Lisanti, Joel

    2017-01-05

    The influence of heat release timing on the performance and operational characteristics of a rotary valve, acoustically resonant pulse combustor is investigated both experimentally and numerically. Simulation results are obtained by solving the quasi-1D Navier-Stokes equations with forced volumetric heat addition. Experimental efforts modify heat release timing through modulated fuel injection and modification of the fluid dynamic mixing. Results indicate that the heat release timing has a profound effect on the operation and efficiency of the pulse combustor and that this timing can be difficult to control experimentally.

  7. Operative variables are better predictors of postdischarge infections and unplanned readmissions in vascular surgery patients than patient characteristics.

    Hicks, Caitlin W; Bronsert, Michael; Hammermeister, Karl E; Henderson, William G; Gibula, Douglas R; Black, James H; Glebova, Natalia O

    2017-04-01

    Although postoperative readmissions are frequent in vascular surgery patients, the reasons for these readmissions are not well characterized, and effective approaches to their reduction are unknown. Our aim was to analyze the reasons for vascular surgery readmissions and to report potential areas for focused efforts aimed at readmission reduction. The 2012 to 2013 American College of Surgeons National Quality Improvement Program (ACS NSQIP) data set was queried for vascular surgery patients. Multivariable models were developed to analyze risk factors for postdischarge infections, the major drivers of unplanned 30-day readmissions. We identified 86,403 vascular surgery patients for analysis. Thirty-day readmission occurred in 8827 (10%), of which 8054 (91%) were unplanned. Of the unplanned readmissions, 61% (n = 4951) were related to the index vascular surgery procedure. Infectious complications were the most common reason for a surgery-related readmission (1940 [39%]), with surgical site infection being the most common type of infection related to unplanned readmission. Multivariable analysis showed the top five preoperative risk factors for postdischarge infections were the presence of a preoperative open wound, inpatient operation, obesity, work relative value unit, and insulin-dependent diabetes (but not diabetes managed with oral medications). Cigarette smoking was a weak predictor and came in tenth in the mode (overall C index, 0.657). When operative and postoperative factors were included in the model, total operative time was the strongest predictor of postdischarge infectious complications (odds ratio [OR] 1.2 for each 1-hour increase in operative time), followed by presence of a preoperative open wound (OR, 1.5), inpatient operation (OR, 2), obesity (OR, 1.8), and discharge to rehabilitation facility (OR, 1.7; P model was fair (C statistic, 0.686). Infectious complications dominate the reasons for unplanned 30-day readmissions in vascular surgery

  8. NO removal characteristics of a corona radical shower system under DC and AC/DC superimposed operations

    Yan, K.; Yamamoto, T.; Kanazawa, S.; Ohkubo, T.; Nomoto, Y.; Chang, Jen-Shih

    2001-01-01

    In this paper, the effects of the applied voltage modes on the positive corona discharge morphology and NO removal characteristics from air streams are experimentally investigated. By using a DC superimposed high frequency AC power supply (10-60 kHz), a uniform streamer corona can be generated,

  9. 18F-fluoro-deoxy-glucose-positron emission tomography/computed tomography in diagnosis of head and neck squamous cell carcinoma

    Rohde, Max; Dyrvig, Anne-Kirstine; Johansen, Jørgen

    2014-01-01

    and qualitatively analysed. Along with the calculated pooled sensitivity and specificity of PET/CT and SCI, bubble- and summary receiver operating characteristics (SROC) plots were created. FINDINGS: Two meta-analyses of diagnostic accuracy were conducted. The first, on PET/CT, included 987 patients distributed...

  10. Personal and socio-psychological characteristics of women of reproductive age, operated on for symptomatic endometriod desease, at the stage of pregnancy planning

    T. P. Chuieva-Pavlovska

    2017-10-01

    Full Text Available Endometrioid disease occurs in every tenth woman of reproductive age and often leads not only to physical discomfort, but also frustrates them psychosocially, reduces professional, psychosocial and reproductive adaptation in general. The aim: to reveal the personal and psychosocial characteristics of women at the stage of pregnancy planning, operated on for symptomatic endometriosis, in connection with the task of optimizing the management and improvement of pregnancy outcomes. Material and methods. Under observation, there were 123 women operated on for symptomatic endometriosis, 125 somatically and gynecologically conditionally healthy fertile women. All the women were going to plan a pregnancy. The diagnosis of endometriosis in all cases was identified histologically. The psychosocial and personal characteristics of these women at the stage of pregnancy planning were studied. Conclusions.  The peculiarities of the personal and psychosocial characteristics of women at the stage of pregnancy planning, operated on for symptomatic endometriosis, are unfavorable child-parent relations, destructive relationships with their own mother, complicated course of pregnancy in the mother, high personal anxiety, impaired sex and age identification in women, inadequate (infantile, disadaptive forms of responding to stressful situations, emotional instability.

  11. Comparative characteristics of the efficiency of different methods of operational treatment for pectus excavatum in children: a multicenter study

    Aleksandr Yu. Razumovsky

    2018-03-01

    Full Text Available Background. Congenital malformations of the chest are observed in 1%–4% of the population, and the most common among these is pectus excavatum (90%. Aim. We aimed to conduct a retrospective multicenter study to compare the effectiveness of various methods of operative removal of pectus excavatum in children. Material and methods. We retrospectively analyzed the results of the surgical treatment of funnel-like deformity of the thorax in children conducted in clinics of pediatric surgery in seven regions of Russia (1,226 patients. The ratio of boys to girls in the study population was 2.2:1. The study population was divided as per their age into the following groups: 4–7 years (n = 180, 14.7%, 8–14 years (n = 731, 59.6%, and > 14 years (n = 315, 25.7%. The average age at which most children were operated was 11.83 ± 1.24 years. All children underwent a standard preoperative laboratory examination, including a general blood test, urine tests, a biochemical blood test, a hemostasiogram; radiographic diagnostic methods were used with the calculation of the Gizycka index; functional methods of investigation, such as electrocardiography, spirography, and radioisotope scintigraphy of the lungs were also used. Children with second- or third-degree pectus excavatum underwent surgical treatment almost exclusively. The symmetrical forms of the pectus excavatum were more prevalent. In most cases, the main pathological course was complicated. Results and discussion. The operated patients were divided into the following 3 groups: the first (n = 62: operations with the resection of the curved cartilages and external fixation of the sternum-rib complex (Bairov’s operation, the second (n = 374: thoracoplasty with the resection of warped cartilages using internal metal fixators by Timoshchenko, Ravitch, Paltia, Kondrashin, and the third (n = 790: minimally invasive operations without resection with internal fixation (Nuss operations: original and modified

  12. Operational conditions and characteristics of ELM-events during H-mode plasmas in the stellarator W7-AS

    Hirsch, M.; Grigull, P.; Wobig, H.; Kisslinger, J.; McCormick, K.; Anton, M.; Baldzuhn, J.; Fiedler, S.; Fuchs, Ch.; Geiger, J.; Giannone, L.; Hartfuss, H.-J.; Holzhauer, E.; Hirsch, M.; Jaenicke, R.; Kick, M.; Maassberg, H.; Wagner, F.; Weller, A.

    2000-01-01

    H-mode operation in the low-shear stellarator W7-AS is achieved for specific plasma edge topologies characterized by three 'operational windows' of the edge rotational transform. An explanation for this strong influence of the magnetic configuration could be the increase of viscous damping if rational surfaces and thus island structures occur within the relevant plasma edge layer, thereby impeding the development of an edge transport barrier. Prior to the final transition to a quiescent state, the plasma edge passes a rich phenomenology of dynamic behaviour such as dithering and ELMs. Plasma edge parameters indicate that a quiescent H-mode occurs if a certain edge pressure is achieved. (author)

  13. Operating characteristic analysis of a 400 mH class HTS DC reactor in connection with a laboratory scale LCC type HVDC system

    Kim, Sung-Kyu; Kim, Kwangmin; Park, Minwon; Yu, In-Keun; Lee, Sangjin

    2015-11-01

    High temperature superconducting (HTS) devices are being developed due to their advantages. Most line commutated converter based high voltage direct current (HVDC) transmission systems for long-distance transmission require large inductance of DC reactor; however, generally, copper-based reactors cause a lot of electrical losses during the system operation. This is driving researchers to develop a new type of DC reactor using HTS wire. The authors have developed a 400 mH class HTS DC reactor and a laboratory scale test-bed for line-commutated converter type HVDC system and applied the HTS DC reactor to the HVDC system to investigate their operating characteristics. The 400 mH class HTS DC reactor is designed using a toroid type magnet. The HVDC system is designed in the form of a mono-pole system with thyristor-based 12-pulse power converters. In this paper, the investigation results of the HTS DC reactor in connection with the HVDC system are described. The operating characteristics of the HTS DC reactor are analyzed under various operating conditions of the system. Through the results, applicability of an HTS DC reactor in an HVDC system is discussed in detail.

  14. Characteristics of the Operational Noise from Full Scale Wave Energy Converters in the Lysekil Project: Estimation of Potential Environmental Impacts

    Mats Leijon

    2013-05-01

    Full Text Available Wave energy conversion is a clean electric power production technology. During operation there are no emissions in the form of harmful gases. However there are unsolved issues considering environmental impacts such as: electromagnetism; the artificial reef effect and underwater noise. Anthropogenic noise is increasing in the oceans worldwide and wave power will contribute to this sound pollution in the oceans; but to what extent? The main purpose of this study was to examine the noise emitted by a full scale operating Wave Energy Converter (WEC in the Lysekil project at Uppsala University in Sweden. A minor review of the hearing capabilities of fish and marine mammals is presented to aid in the conclusions of impact from anthropogenic sound. A hydrophone was deployed to the seabed in the Lysekil research site park at distance of 20 and 40 m away from two operational WECs. The measurements were performed in the spring of 2011. The results showed that the main noise was a transient noise with most of its energy in frequencies below 1 kHz. These results indicate that several marine organisms (fish and mammals will be able to hear the operating WECs of a distance of at least 20 m.

  15. Fatigue crack growth characteristics of nitrogen-alloyed type 347 stainless under operating conditions of a pressurized water reactor

    Min, Ki Deuk; Hong, Seok Min; Kim, Dae Whan; Lee, Bong Sang [Korea Atomic Energy Research Institute, Nuclear Materials Safety Research Division, Daejeon (Korea, Republic of); Kim, Seon Jin [Hanyang University, Division of materials science and engineering, Seoul (Korea, Republic of)

    2017-06-15

    The fatigue crack growth behavior of Type 347 (S347) and Type 347N (S347N) stainless steel was evaluated under the operating conditions of a pressurized water reactor (PWR). These two materials showed different fatigue crack growth rates (FCGRs) according to the changes in dissolved oxygen content and frequency. Under the simulated PWR conditions for normal operation, the FCGR of S347N was lower than that of S347 and insensitive to the changes in PWR water conditions. The higher yield strength and better corrosion resistance of the nitrogen-alloyed Type 347 stainless steel might be a main cause of slower FCGR and more stable properties against changes in environmental conditions.

  16. The Effect of Influent Characteristics and Operational Conditions over the Performance and Microbial Community Structure of Partial Nitritation Reactors

    Alejandro Rodriguez-Sanchez

    2014-06-01

    Full Text Available Nitrogen is a main contaminant of wastewater worldwide. Novel processes for nitrogen removal have been developed over the last several decades. One of these is the partial nitritation process. This process includes the oxidation of ammonium to nitrite without the generation of nitrate. The partial nitritation process has several advantages over traditional nitrification-denitrification processes for nitrogen removal from wastewaters. In addition, partial nitritation is required for anammox elimination of nitrogen from wastewater. Partial nitritation is affected by operational conditions and substances present in the influent, such as quinolone antibiotics. In this review, the impact that several operational conditions, such as temperature, pH, dissolved oxygen concentration, hydraulic retention time and solids retention time, have over the partial nitritation process is covered. The effect of quinolone antibiotics and other emerging contaminants are discussed. Finally, future perspectives for the partial nitritation process are commented upon.

  17. Fabrication of Free Air Well Type Ionization Chamber and Calculational Assessment and Measurement of Its Operational Characteristics

    Koroush Arbabi

    2007-12-01

    Full Text Available Introduction: Well type ionization chamber is a measuring device which is used to determine the activity of brachytherapy sources. The chamber has a cylindrical volume in which a cylindrical tube is mounted in the middle of the chamber. For the measurements, the brachytherapy sources are transferred to the middle of the tube. Materials and Methods: For designing the well type chamber, the measurement principals of well type chambers were considered and MCNP-4C code as a calculation tool was used. The designed chamber was simulated and the response of the chamber was evaluated. In this investigation, the chamber operational parameters such as operating voltage, leakage current, reproducibility, reference measuring point, recombination and polarization factors as well as response stability for 137Cs, 57Co and 241Am sources were studied. Results: The chamber leakage currents at the operating voltage in comparison to the chamber response for the measurement of the above mentioned sources were negligible. The responses of the fabricated chamber for these sources are reproducible and its reference measurement position for these sources was obtained at 6 cm from the bottom of the chamber. The recombination factor for the well type chamber was negligible and the polarization factor is close to 1. Therefore, these two factors were not considered in the measurements. The reproducibility of the measurements in different intervals shows the stability of the chamber response for each source. Also the results of the chamber current measurement in term of source strength were compared to the response of the simulated chamber for different source positions and energy ranges of the used sources. Discussion and Conclusion: The results show that the measurement of the reference positions for each source in the simulated and fabricated chamber is quite in a good agreement. Regarding the reliable operational properties of the fabricated chamber, this chamber can be

  18. Characteristics of the Operational Noise from Full Scale Wave Energy Converters in the Lysekil Project : Estimation of Potential Environmental Impacts

    Haikonen, Kalle; Sundberg, Jan; Leijon, Mats

    2013-01-01

    Wave energy conversion is a clean electric power production technology. During operation there are no emissions in the form of harmful gases. However there are unsolved issues considering environmental impacts such as: electromagnetism; the artificial reef effect and underwater noise. Anthropogenic noise is increasing in the oceans worldwide and wave power will contribute to this sound pollution in the oceans; but to what extent? The main purpose of this study was to examine the noise emitted...

  19. Impacts from electric railway operation on the power supply system characteristic; Einfluss des elektrischen Bahnbetriebs auf das Tagesbelastungsdiagramm der Energieversorgung

    Bogdanov, C. [Militaerhochschule fuer Verkehr ``Todor Kableshkov``, Sofia (Bulgaria)

    1995-12-31

    Some characteristic figures are derived from daily load diagrams of electric railways, analized and compared with those of public power supply load diagram, especially with regard to sharing in base - medium - peak load and in day - night times, and optimizations are proposed. (orig.) [Deutsch] Fuer die Tagesbelastungsdiagramme elektrischer Bahnen werden einige Kennziffern gebildet, analysiert und mit denen des Tagesbelastungsdiagramms der Landesenergieversorgung verglichen, insbesondere hinsichtlich der Verteilung des Bahnenergiebedarfs auf Grund-, Mittel- und Spitzenlast sowie auf die verschiedenen Tages- und Nachtzeitzonen. Daraus werden Optimierungsvorschlaege abgeleitet. (orig.)

  20. Combustion and exhaust emission characteristics of a dual fuel compression ignition engine operated with pilot Diesel fuel and natural gas

    Papagiannakis, R.G.; Hountalas, D.T.

    2004-01-01

    Towards the effort of reducing pollutant emissions, especially soot and nitrogen oxides, from direct injection Diesel engines, engineers have proposed various solutions, one of which is the use of a gaseous fuel as a partial supplement for liquid Diesel fuel. These engines are known as dual fuel combustion engines, i.e. they use conventional Diesel fuel and a gaseous fuel as well. This technology is currently reintroduced, associated with efforts to overcome various difficulties of HCCI engines, using various fuels. The use of natural gas as an alternative fuel is a promising solution. The potential benefits of using natural gas in Diesel engines are both economical and environmental. The high autoignition temperature of natural gas is a serious advantage since the compression ratio of conventional Diesel engines can be maintained. The present contribution describes an experimental investigation conducted on a single cylinder DI Diesel engine, which has been properly modified to operate under dual fuel conditions. The primary amount of fuel is the gaseous one, which is ignited by a pilot Diesel liquid injection. Comparative results are given for various engine speeds and loads for conventional Diesel and dual fuel operation, revealing the effect of dual fuel combustion on engine performance and exhaust emissions

  1. Operating methods to remove the excess of penetrant in surface. Preponderant and characteristic part of water for water washable penetrants

    Dubosc, P.

    1985-01-01

    Penetrant use for quality control, although very well known (nuclear, space industries, offshore platforms) is often poorly practiced. This is largely due to a lack of understanding by the users the way that the different components of the system (penetrants, solvents, emulsifiers, and developers) function. In this talk, we shall explain a particular characteristic that the manufacturers of reputable penetrant seek to build into their water washable penetrants. It is a viscosity curve which has the function of keeping water in a well defined form. We show why the form of the curve is crucial, which reaction between water and penetrant it corresponds to, and we deduce the practical consequences of bringing into play procedures for removing excess penetrant with or without water [fr

  2. Operating characteristics of a single-stage Stirling cryocooler capable of providing 700 W cooling power at 77 K

    Xu, Ya; Sun, Daming; Qiao, Xin; Yu, Yan S. W.; Zhang, Ning; Zhang, Jie; Cai, Yachao

    2017-04-01

    High cooling capacity Stirling cryocooler generally has hundreds to thousands watts of cooling power at liquid nitrogen temperature. It is promising in boil-off gas (BOG) recondensation and high temperature superconducting (HTS) applications. A high cooling capacity Stirling cryocooler driven by a crank-rod mechanism was developed and studied systematically. The pressure and frequency characteristics of the cryocooler, the heat rejection from the ambient heat exchanger, and the cooling performance are studied under different charging pressure. Energy conversion and distribution in the cryocooler are analyzed theoretically. With an electric input power of 10.9 kW and a rotating speed of 1450 r/min of the motor, a cooling power of 700 W at 77 K and a relative Carnot efficiency of 18.2% of the cryocooler have been achieved in the present study, and the corresponding pressure ratio in the compression space reaches 2.46.

  3. Adjusting the operating characteristics to improve the performance of an emulsified palm oil methyl ester run diesel engine

    Debnath, Biplab K.; Sahoo, Niranjan; Saha, Ujjwal K.

    2013-01-01

    Highlights: ► The oxygenated biodiesel has a lower calorific value and emits higher NO X than diesel. ► The objective is to study the water in palm oil biodiesel emulsion in a diesel engine. ► The tests are performed at higher compression ratio and retarded injection timing. ► The results obtained are compared with a POME run diesel engine. ► Higher efficiency, lower ignition delay and emissions are the outcomes. - Abstract: The popularity of emulsified fuels as alternative to diesel is cumulative. The water in diesel emulsion is the most practiced one. The presence of water in emulsion and its micro-explosion reduces emissions. However, the emulsified biodiesel is not properly explored. The reason may be due to its lesser calorific value that does not augment efficiency. Alongside oxygenated biodiesel generally emits higher NO X than diesel. Therefore, the present investigation targets at finding the performance, combustion and emission characteristics of emulsified biodiesel in a diesel engine at an elevated compression ratio (CR) and retarded injection timing (IT). This is because; at this CR–IT combination emulsified fuel will be injected at the warmer environment, mechanically created inside the cylinder. The objective is to achieve a faster combustion, lower ignition delay (ID), improved performance and emission characteristics. The biodiesel used in this work is the palm oil methyl ester (POME). The prepared two-phase water in POME (WIP) emulsion is tested in a variable compression ratio (VCR) diesel engine at CR = 18 and IT = 20°BTDC. The results obtained are then compared with the POME run engine data under the same CR and IT specifications. Additionally, experiments have also been conducted in the same engine at CR = 17.5 and IT = 23°BTDC to compare its results with those of WIP and POME run engines

  4. Operation characteristic of a R123-based organic Rankine cycle depending on working fluid mass flow rates and heat source temperatures

    Feng, Yong-Qiang; Hung, Tzu-Chen; Wu, Shang-Lun; Lin, Chih-Hung; Li, Bing-Xi; Huang, Kuo-Chen; Qin, Jiang

    2017-01-01

    Highlights: • The operation characteristic of an Organic Rankine Cycle using R123 and a scroll expander have been investigated. • The behaviors and detailed discussion for those four major components are examined. • The expander isentropic efficiency presents a slight decrease first and then a sharp increase with mass flow rate. • The maximum electrical power and system generation efficiency are 2.01 kW and 3.25%, respectively. - Abstract: The test and operation characteristic of an organic Rankine cycle using R123 and a scroll expander have been investigated. The steady-state operation characteristic is addressed with the varying working fluid mass flow rates ranging of 0.124–0.222 kg/s and heat source temperatures ranging of 383.15–413.15 K. The behaviors and detailed discussion for those four major components (pump, evaporator, expander and condenser) are examined. The experimental results show that the environmental temperature presents a higher influence on the pump behaviors. The range of pump power consumption, isentropic efficiency and back work ratio are 0.21–0.32 kW, 26.76–53.96%, and 14–32%, respectively. The expander isentropic efficiency presents a slight decrease first and then a sharp increase with mass flow rate, while a degree of superheating more than 3 K is necessary to avoid expander cavitation. The expander isentropic and generator efficiencies are in range of 69.10–85.17% and 60–73%, respectively, while the respective heat transfer coefficients for evaporator and condenser are ranging of 200–400 and 450–2000 W/m"2 K. The maximum expander shaft power and electrical power are 2.78 kW and 2.01 kW, respectively, while the maximum system generating efficiency is 3.25%. Moreover, the tested thermal efficiency presents a slight decrease trend with mass flow rate.

  5. Experimental characteristics of a high-gain free-electron laser amplifier operating at 8-mm and 2-mm wavelengths

    Throop, A.L.; Orzechowski, T.J.; Anderson, B.R.

    1987-01-01

    The Electron Laser Facility (ELF) at the Lawrence Livermore National Laboratory (LLNL) uses a high-current induction linac (3.5 MeV, 1000 A), in conjunction with a pulsed electromagnetic wiggler (4.0 M, 4000 G), to operate a free electron laser (FEL) that produces intense radiation in the microwave regime (2 to 8 mm). ELF is a high-gain, single-pass amplifier, using a commercial microwave source as an oscillator input (200 W-50 kW). Previous experiments at 35 GHz produced exponential gains of 40 dB/m, peak powers exceeding 1 GW, and beam-to-rf conversion efficiencies of 34%. Recent experiments at 140 GHz have demonstrated exponential gains of 22 dB/m, peak powers exceeding 50 MW, and total gains of 65 dB. In this paper, we describe the experimental results at these two frequencies and compare then with the predictions of simulation codes

  6. Construction of a self-supporting tissue-equivalent dividing wall and operational characteristics of a coaxial double-cylindrical tissue-equivalent proportional counter

    Saion, E.B.; Watt, D.E.

    1994-01-01

    An additional feature incorporated in a coaxial double-cylindrical tissue-equivalent proportional counter, is the presence of a common tissue-equivalent dividing wall between the inner and outer counters of thickness equivalent to the corresponding maximum range of protons at the energy of interest. By appropriate use of an anti-coincidence arrangement with the outer counter, the inner counter could be used to discriminate microdosimetric spectra of neutrons at the desired low energy range from those of the faster neutrons. The construction of an A-150 self-supporting tissue-equivalent dividing wall and an anti-coincidence unit are described. Some operational characteristic tests have been performed to determine the operation of the new microdosimeter. (author)

  7. Operating characteristic analysis of a 400 mH class HTS DC reactor in connection with a laboratory scale LCC type HVDC system

    Kim, Sung-Kyu, E-mail: power@changwon.ac.kr [Changwon National University, 55306 Sarim-dong, Changwon 641-773 (Korea, Republic of); Kim, Kwangmin; Park, Minwon [Changwon National University, 55306 Sarim-dong, Changwon 641-773 (Korea, Republic of); Yu, In-Keun, E-mail: yuik@changwon.ac.kr [Changwon National University, 55306 Sarim-dong, Changwon 641-773 (Korea, Republic of); Lee, Sangjin [Uiduk University, Gyeongju 780-713 (Korea, Republic of)

    2015-11-15

    Highlights: • A 400 mH class HTS DC reactor and a laboratory scale test-bed for line-commutated converter type HVDC transmission system. • The 400 mH class HTS DC reactor was connected to real power network via the HVDC system. • The DC current flowed in HTS DC reactor has several harmonic components and it was analyzed using FFT. - Abstract: High temperature superconducting (HTS) devices are being developed due to their advantages. Most line commutated converter based high voltage direct current (HVDC) transmission systems for long-distance transmission require large inductance of DC reactor; however, generally, copper-based reactors cause a lot of electrical losses during the system operation. This is driving researchers to develop a new type of DC reactor using HTS wire. The authors have developed a 400 mH class HTS DC reactor and a laboratory scale test-bed for line-commutated converter type HVDC system and applied the HTS DC reactor to the HVDC system to investigate their operating characteristics. The 400 mH class HTS DC reactor is designed using a toroid type magnet. The HVDC system is designed in the form of a mono-pole system with thyristor-based 12-pulse power converters. In this paper, the investigation results of the HTS DC reactor in connection with the HVDC system are described. The operating characteristics of the HTS DC reactor are analyzed under various operating conditions of the system. Through the results, applicability of an HTS DC reactor in an HVDC system is discussed in detail.

  8. Operating characteristic analysis of a 400 mH class HTS DC reactor in connection with a laboratory scale LCC type HVDC system

    Kim, Sung-Kyu; Kim, Kwangmin; Park, Minwon; Yu, In-Keun; Lee, Sangjin

    2015-01-01

    Highlights: • A 400 mH class HTS DC reactor and a laboratory scale test-bed for line-commutated converter type HVDC transmission system. • The 400 mH class HTS DC reactor was connected to real power network via the HVDC system. • The DC current flowed in HTS DC reactor has several harmonic components and it was analyzed using FFT. - Abstract: High temperature superconducting (HTS) devices are being developed due to their advantages. Most line commutated converter based high voltage direct current (HVDC) transmission systems for long-distance transmission require large inductance of DC reactor; however, generally, copper-based reactors cause a lot of electrical losses during the system operation. This is driving researchers to develop a new type of DC reactor using HTS wire. The authors have developed a 400 mH class HTS DC reactor and a laboratory scale test-bed for line-commutated converter type HVDC system and applied the HTS DC reactor to the HVDC system to investigate their operating characteristics. The 400 mH class HTS DC reactor is designed using a toroid type magnet. The HVDC system is designed in the form of a mono-pole system with thyristor-based 12-pulse power converters. In this paper, the investigation results of the HTS DC reactor in connection with the HVDC system are described. The operating characteristics of the HTS DC reactor are analyzed under various operating conditions of the system. Through the results, applicability of an HTS DC reactor in an HVDC system is discussed in detail.

  9. THE CHARACTERISTICS OF THE OPERATING PARAMETERS OF THE VERTICAL AXIS WIND TURBINE FOR THE SELECTED WIND SPEED

    Zbigniew Czyż

    2017-03-01

    Full Text Available The article presents the results of examining a wind turbine on the vertical axis of rotation. The study was conducted in an open circuit wind tunnel Gunt HM 170 in the laboratory of the Department of Thermodynamics, Fluid Mechanics and Aviation Propulsion Systems in Lublin University of Technology. The subject of research was a rotor based on the patent PL 219985. The research object in the form of rotor consists of blades capable of altering the surface of the active area (receiving kinetic energy of the wind. The study was performed on appropriately scaled and geometrically similar models with maintaining, relevant to the type of research, the criterion numbers. Research objects in the form of rotors with different angles of divergence of blades were made using a 3D powder printer ZPrinter® 450. The results of the research conducted were carried out at the selected flow velocity of 6.5 m/s for three angles of divergence, ie. 30°, 60°, and 90° at variable rotational speed. The applied research station allows braking of the turbine to the required speed, recording velocity and torque, which allows to obtain characteristics of torque and power as a function of rotor speed.

  10. Personality factors in flight operations. Volume 1: Leader characteristics and crew performance in a full-mission air transport simulation

    Chidester, Thomas R.; Kanki, Barbara G.; Foushee, H. Clayton; Dickinson, Cortlandt L.; Bowles, Stephen V.

    1990-01-01

    Crew effectiveness is a joint product of the piloting skills, attitudes, and personality characteristics of team members. As obvious as this point might seem, both traditional approaches to optimizing crew performance and more recent training development highlighting crew coordination have emphasized only the skill and attitudinal dimensions. This volume is the first in a series of papers on this simulation. A subsequent volume will focus on patterns of communication within crews. The results of a full-mission simulation research study assessing the impact of individual personality on crew performance is reported. Using a selection algorithm described in previous research, captains were classified as fitting one of three profiles along a battery of personality assessment scales. The performances of 23 crews led by captains fitting each profile were contrasted over a one-and-one-half-day simulated trip. Crews led by captains fitting a positive Instrumental-Expressive profile (high achievement motivation and interpersonal skill) were consistently effective and made fewer errors. Crews led by captains fitting a Negative Expressive profile (below average achievement motivation, negative expressive style, such as complaining) were consistently less effective and made more errors. Crews led by captains fitting a Negative Instrumental profile (high levels of competitiveness, verbal aggressiveness, and impatience and irritability) were less effective on the first day but equal to the best on the second day. These results underscore the importance of stable personality variables as predictors of team coordination and performance.

  11. Design and dosimetry characteristics of a commercial applicator system for intra-operative electron beam therapy utilizing ELEKTA Precise accelerator.

    Nevelsky, Alexander; Bernstein, Zvi; Bar-Deroma, Raquel; Kuten, Abraham; Orion, Itzhak

    2010-07-19

    The design concept and dosimetric characteristics of a new applicator system for intraoperative radiation therapy (IORT) are presented in this work. A new hard-docking commercial system includes polymethylmethacrylate (PMMA) applicators with different diameters and applicator end angles and a set of secondary lead collimators. A telescopic device allows changing of source-to-surface distance (SSD). All measurements were performed for 6, 9, 12 and 18 MeV electron energies. Output factors and percentage depth doses (PDD) were measured in a water phantom using a plane-parallel ion chamber. Isodose contours and radiation leakage were measured using a solid water phantom and radiographic films. The dependence of PDD on SSD was checked for the applicators with the smallest and the biggest diameters. SSD dependence of the output factors was measured. Hardcopies of PDD and isodose contours were prepared to help the team during the procedure on deciding applicator size and energy to be chosen. Applicator output factors are a function of energy, applicator size and applicator type. Dependence of SSD correction factors on applicator size and applicator type was found to be weak. The same SSD correction will be applied for all applicators in use for each energy. The radiation leakage through the applicators is clinically acceptable. The applicator system enables effective collimation of electron beams for IORT. The data presented are sufficient for applicator, energy and monitor unit selection for IORT treatment of a patient.

  12. Numerical modeling of the effects of a free surface on the operating characteristics of Marine Hydrokinetic Turbines

    Adamski, Samantha; Aliseda, Alberto

    2012-11-01

    Marine Hydrokinetic (MHK) turbines are a growing area of research in the renewable energy field because tidal currents are a highly predictable clean energy source. The presence of a free surface may influence the flow around the turbine and in the wake, critically affecting turbine performance and environmental effects through modification of wake physical variables. The characteristic Froude number that control these processes is still a matter of controversy, with the channel depth and turbine's depth, blade tip depth and diameter as potential candidates for a length scale used in literature. We use the Volume of Fluid model to track the free surface dynamics in a RANS simulation with a BEMT model of the turbine to understand the physics of the wake-free surface interactions. Pressure and flow rate boundary conditions for channel's inlet, outlet and air side have been tested in an effort to determine the optimum set of simulation conditions for MHK turbines in rivers or estuaries. Stability and accuracy in terms of power extraction and kinetic and potential energy budgets are considered. The goal of this research is to determine, quantitatively in non dimensional parameter space, the limit between negligible and significant free surface effects on MHK turbine analysis. Supported by DOE through the National Northwest Marine Renewable Energy Center.

  13. Startup and operating characteristics of an external air-lift reflux partial nitritation-ANAMMOX integrative reactor.

    Li, Xiang; Huang, Yong; Yuan, Yi; Bi, Zhen; Liu, Xin

    2017-08-01

    The differences in the physiological characteristics between AOB and ANAMMOX bacteria lead to suboptimal performance when used in a single reactor. In this study, aerobic and anaerobic zones with different survival environments were constructed in a single reactor to realize partitioned culture of AOB and ANAMMOX bacteria. An external air-lift reflux system was formed which used the exhaust from the aeration zone as power to return the effluent to the aeration zone. The reflux system effectively alleviated the large pH fluctuations and promoted NO 2 - -N to rapidly use by ANAMMOX bacteria, effectively inhibiting the activity of NOB. After 95d of running, the nitrogen removal rate increased from the initial 0.21kg/(m 3 ·d) to 3.1kg/(m 3 ·d). FISH analyses further demonstrated that AOB and ANAMMOX bacteria acquired efficient enrichment in the corresponding zone. Thus, this type of integrative reactor may create the environments needed for the partial nitritation-ANAMMOX processing. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Effects of Engine Cooling Water Temperature on Performance and Emission Characteristics of a Ci Engine Operated with Biofuel Blend

    Abul Hossain

    2017-03-01

    Full Text Available The temperature of the coolant is known to have significant influence on engine performance and emissions. Whereas existing literature describes the effects of coolant temperature in engines using fossil derived fuels, very few studies have investigated these effects when biofuel is used. In this study, Jatropha oil was blended separately with ethanol and butanol. It was found that the 80% jatropha oil + 20% butanol blend was the most suitable alternative, as its properties were closest to that of fossil diesel. The coolant temperature was varied between 50°C and 95°C. The combustion process enhanced for both diesel and biofuel blend, when the coolant temperature was increased. The carbon dioxide emissions for both diesel and biofuel blend were observed to increase with temperature. The carbon monoxide, oxygen and lambda values were observed to decrease with temperature. When the engine was operated using diesel, nitrogen oxides emissions correlated in an opposite manner to smoke opacity; however, nitrogen oxides emissions and smoke opacity correlated in an identical manner for biofuel blend. Brake specific fuel consumption was observed to decrease as the temperature was increased and was higher on average when the biofuel was used. The study concludes that both biofuel blend and fossil diesel produced identical correlations between coolant temperature and engine performance. The trends of nitrogen oxides and smoke emissions with cooling temperatures were not identical to fossil diesel when biofuel blend was used in the engine.

  15. Characteristics of hemostasis system and hemorrhagic syndrome in infants with congenital heart disease in operations with cardiopulmonary bypass

    Н. П. Леонов

    2016-01-01

    Full Text Available 97 neonates were included in this prospective observational study. While using the exclusion criteria, two groups without demographic differences were formed: the first group included 35 patients with blood loss greater than 10 ml/kg in the first 4 hours postoperatively, the second one consisted of 46 patients who did not have such blood loss. Hemostatic standard tests and thromboelastography were performed before surgery, immediately after surgery and 24 hours after it. As a result, a detailed description of the changes of hemostasis in the perioperative period in newborns with CHD was developed. It was found out that significant postoperative bleeding increases the incidence of coagulopathy, resuscitation after surgery, duration of mechanical ventilation, length of stay at ICU and 30-day mortality. It is confirmed that the main pathogenetic mechanisms of increased bleeding in the first hours after the operation are due to cardiopulmonary bypass coagulopathy, the dynamics and implications of which are documented in our study. Also established are prognostic clinical and laboratory predictors of coagulopathy associated with severe multiple organ failure.

  16. Is pain during pediatric dental sedation associated with children’s pre-operative characteristics? An exploratory study

    Jordanna Guedes Amorim MENDONÇA

    Full Text Available Abstract Introduction Little is known about the factors associated with the pain of children in dental treatment under conscious sedation. Objective To investigate the association between preoperative characteristics and pain during pediatric dental treatment under sedation. Material and method This exploratory study was conducted with 27 children in restorative treatment under sedation. Information on age, sex and experience of the children with previous dental treatment was obtained through interviews with parents. Oral health status, determined from the presence of dental caries, was verified using the dmf-t index. Pain was assessed by analyzing videos of the dental treatments by two previously calibrated examiners, using the items “legs”, “activity” and “crying” of the observational scale “face, legs, activity, consolability and crying” (FLACC. Data were analyzed using bivariate tests. Result Most of the children (n=14, 51.8% had no pain during dental treatment under sedation. Among the other children, lower or moderate pain scores (median 1.1; minimum 0 to 3.8 were observed. The FLACC scores did not vary according to sex (P=0.38, previous experience with dental treatment (P=0.32 and history with local anesthesia (P=0.96. The FLACC scores did not correlate significantly with age (Spearman rho= -0.08, P=0.67 and dmf-t (Spearman rho= -0.04, P=0.84. Conclusion In this group of children, pain during dental treatment under sedation was of low frequency and intensity and did not associate with age, sex, oral condition and previous dental experience.

  17. Plasma characteristics in an electrically asymmetric capacitive discharge sustained by multiple harmonics: operating in the very high frequency regime

    Zhang, Yu-Ru; Hu, Yan-Ting; Gao, Fei; Song, Yuan-Hong; Wang, You-Nian

    2018-05-01

    A novel method, the so-called electrical asymmetry effect (EAE), is gaining increasing interest for realizing the separate control of the ion flux and ion energy. In this paper, a two-dimensional fluid model combined with the full set of Maxwell equations is used to investigate the plasma properties in an electrically asymmetric capacitive discharge sustained by multiple consecutive harmonics operating in the very high frequency regime. The results indicate that by increasing the total number of consecutive harmonics k, the modulation of the dc self-bias induced by changing {θ }1 (the relative phase of the fundamental frequency) becomes different, especially for k ≤slant 6. In a discharge driven by eight consecutive harmonics, the dc self-bias varies with a period 2π, and the most positive value appears at {θ }1 = 3π/2. In addition, with the electromagnetic effects taken into account, the plasma density shifts from edge-high to uniform when {θ }1 increases from 0 to π, and the maximum moves again towards the radial wall at {θ }1 = 3π/2. Moreover, the transient behavior of electrodynamics is also important for a better understanding of the EAE. Within a period, three positive peaks of {P}z are observed, which cause substantial ionization at similar places. {P}r is characterized by a pronounced peak at the end of the period, and the lowest peak value appears at {θ }1 = π. The results obtained in this work are important for improving the plasma processes by utilizing the EAE, especially when the higher order harmonics are included.

  18. Operating Characteristics of Statistical Methods for Detecting Gene-by-Measured Environment Interaction in the Presence of Gene-Environment Correlation under Violations of Distributional Assumptions.

    Van Hulle, Carol A; Rathouz, Paul J

    2015-02-01

    Accurately identifying interactions between genetic vulnerabilities and environmental factors is of critical importance for genetic research on health and behavior. In the previous work of Van Hulle et al. (Behavior Genetics, Vol. 43, 2013, pp. 71-84), we explored the operating characteristics for a set of biometric (e.g., twin) models of Rathouz et al. (Behavior Genetics, Vol. 38, 2008, pp. 301-315), for testing gene-by-measured environment interaction (GxM) in the presence of gene-by-measured environment correlation (rGM) where data followed the assumed distributional structure. Here we explore the effects that violating distributional assumptions have on the operating characteristics of these same models even when structural model assumptions are correct. We simulated N = 2,000 replicates of n = 1,000 twin pairs under a number of conditions. Non-normality was imposed on either the putative moderator or on the ultimate outcome by ordinalizing or censoring the data. We examined the empirical Type I error rates and compared Bayesian information criterion (BIC) values. In general, non-normality in the putative moderator had little impact on the Type I error rates or BIC comparisons. In contrast, non-normality in the outcome was often mistaken for or masked GxM, especially when the outcome data were censored.

  19. Improved diagnostic performance of exercise thallium-201 single photon emission computed tomography over planar imaging in the diagnosis of coronary artery disease: a receiver operating characteristic analysis

    Fintel, D.J.; Links, J.M.; Brinker, J.A.; Frank, T.L.; Parker, M.; Becker, L.C.

    1989-01-01

    Qualitative interpretation of tomographic and planar scintigrams, a five point rating scale and receiver operating characteristic analysis were utilized to compare single photon emission computed tomography and conventional planar imaging of myocardial thallium-201 uptake in the accuracy of the diagnosis of coronary artery disease and individual vessel involvement. One hundred twelve patients undergoing cardiac catheterization and 23 normal volunteers performed symptom-limited treadmill exercise, followed by stress and redistribution imaging by both tomographic and planar techniques, with the order determined randomly. Paired receiver operating characteristic curves revealed that single photon emission computed tomography was more accurate than planar imaging over the entire range of decision thresholds for the overall detection and exclusion of coronary artery disease and involvement of the left anterior descending and left circumflex coronary arteries. Tomography offered relatively greater advantages in male patients and in patients with milder forms of coronary artery disease, who had no prior myocardial infarction, only single vessel involvement or no lesion greater than or equal to 50 to 69%. Tomography did not appear to provide improved diagnosis in women or in detection of disease in the right coronary artery. Although overall detection of coronary artery disease was not improved in patients with prior myocardial infarction, tomography provided improved identification of normal and abnormal vascular regions. These results indicate that single photon emission computed tomography provides improved diagnostic performance compared with planar imaging in many clinical subgroups

  20. The anchor-based minimal important change, based on receiver operating characteristic analysis or predictive modeling, may need to be adjusted for the proportion of improved patients.

    Terluin, Berend; Eekhout, Iris; Terwee, Caroline B

    2017-03-01

    Patients have their individual minimal important changes (iMICs) as their personal benchmarks to determine whether a perceived health-related quality of life (HRQOL) change constitutes a (minimally) important change for them. We denote the mean iMIC in a group of patients as the "genuine MIC" (gMIC). The aims of this paper are (1) to examine the relationship between the gMIC and the anchor-based minimal important change (MIC), determined by receiver operating characteristic analysis or by predictive modeling; (2) to examine the impact of the proportion of improved patients on these MICs; and (3) to explore the possibility to adjust the MIC for the influence of the proportion of improved patients. Multiple simulations of patient samples involved in anchor-based MIC studies with different characteristics of HRQOL (change) scores and distributions of iMICs. In addition, a real data set is analyzed for illustration. The receiver operating characteristic-based and predictive modeling MICs equal the gMIC when the proportion of improved patients equals 0.5. The MIC is estimated higher than the gMIC when the proportion improved is greater than 0.5, and the MIC is estimated lower than the gMIC when the proportion improved is less than 0.5. Using an equation including the predictive modeling MIC, the log-odds of improvement, the standard deviation of the HRQOL change score, and the correlation between the HRQOL change score and the anchor results in an adjusted MIC reflecting the gMIC irrespective of the proportion of improved patients. Adjusting the predictive modeling MIC for the proportion of improved patients assures that the adjusted MIC reflects the gMIC. We assumed normal distributions and global perceived change scores that were independent on the follow-up score. Additionally, floor and ceiling effects were not taken into account. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Development of technologies on innovative-simplified nuclear power plant using high-efficiency steam injectors (5) operating characteristics of center water jet type supersonic steam injector

    Abe, Y.; Kawamoto, Y.; Iwaki, C.; Narabayashi, T.; Mori, M.; Ohmori, S.

    2005-01-01

    Next-generation reactor systems have been under development aiming at simplified system and improvement of safety and credibility. A steam injector has a function of a passive pump without large motor or turbo-machinery, and has been investigated as one of the most important component of the next-generation reactor. Its performance as a pump depends on direct contact condensation phenomena between a supersonic steam and a sub-cooled water jet. As previous studies of the steam injector, there are studies about formulation of operating characteristic of steam injector and analysis of jet structure in steam injector by Narabayashi etc. And as previous studies of the direct contact condensation, there is the study about the direct contact condensation in steam atmosphere. However the study about the turbulent heat transfer under the great shear stress is not enough investigated. Therefore it is necessary to examine in detail about the operating characteristic of the steam injector. The present paper reports the observation results of the water jet behavior in the super sonic steam injector by using the video camera and the high-speed video camera. And the measuring results of the temperature and the pressure distribution in the steam injector are reported. From observation results by video camera, it is cleared that the water jet is established at the center of the steam injector right after steam supplied and the operation of the steam injector depends on the throat diameter. And from observation results by high-speed video camera, it is supposed that the columned water jet surface is established in the mixing nozzle and the water jet surface movement exists. And from temperature measuring results, it is supposed that the steam temperature at the mixing nozzle is changed between about 80 degree centigrade and about 60 degree centigrade. Then from the pressure measuring results, it is confirmed that the pressure at the diffuser depends on each the throat diameter and

  2. Receiver operating characteristics of diagnostic efficacy of resting left ventricular performance (evaluating with a non-imaging ECG gated scintillation detector - nuclear stethoscope)

    Kotlyarov, E.V.; Reba, R.C.; Lindsay, J.

    1983-01-01

    Receiver operating characteristic (ROC) analysis of left ventricular performance at rest was applied to evaluate diagnostic utility of non-imaging nuclear detector (''Nuclear Stethoscope''), for screening patients with coronary artery disease (CAD). Thirty-one patients without CAD and normal rest and stress radionuclide ventriculography (MUGA) were used as a control group. Another 62 patients with abnormal left ventricular reserve and segmental wall motion abnormalities at rest were also studied. All 93 patients were studied with the Nuclear Stethoscope (30 minutes after conventional MUGA testing) both in beat-to-beat and gated equilibrium modes. ROC analysis showed that along with ejection fraction, stroke and end-diastolic volumes, evaluation of the left ventricular filling phase has a great potential for the identification of patients with a segmental wall motion abnormality and, therefore, significant CAD

  3. Paired receiver operating characteristic curves and the effect of history on radiographic interpretation: CT of the head as a case study

    McNeil, B.J.; Hanley, J.A.; Funkenstein, H.H.; Wallman, J.

    1983-01-01

    The use of a statistical technique for paired comparisons using receiver operating characteristic (ROC) curves is illustrated by studying the extent to which clinical history altered the interpretation of computed tomographic (CT) examinations of the head. Eighty-nine CT examinations of the head were presented in random order to four readers, first with minimum history (age and sex) and then several weeks later with complete neutrological history as of the time the CT examination had been obtained. Using a paired ROC analysis, a small but significant (p < .05) improvement was detected for the interpretations in the presence of complete history; for readings without history the average area was 94.4% and for readings with history it was 97.7%

  4. Kinetics of the processes, plasma parameters, and output characteristics of a UV emitter operating on XeI molecules and iodine molecules and atoms

    Shuaibov, A. K.; Grabovaya, I. A.; Minya, A. I.; Homoki, Z. T. [Uzhgorod National University (Ukraine); Kalyuzhnaya, A. G.; Shchedrin, A. I. [National Academy of Sciences of Ukraine, Institute of Physics (Ukraine)

    2011-03-15

    A kinetic model of the processes occurring in the plasma of a high-power low-pressure gas-discharge lamp is presented, and the output characteristics of the lamp are described. The lamp is excited by a longitudinal glow discharge and emits the I{sub 2}(D Prime -A Prime ) 342-nm and XeI(B-X) 253-nm bands and the 206.2-nm spectral line of atomic iodine. When the emitter operates in a sealed-off mode on the p(He): p(Xe): p(I{sub 2}) = 400: 120: (100-200) Pa mixture, the fractions of the UV radiation power of iodine atoms, exciplex molecules of xenon iodide, and iodine molecules comprise 55, 10, and 35%, respectively. At the optimal partial pressure, the maximum total radiation power of the lamp reaches 37 W, the energy efficiency being about 15%.

  5. Receiver-operating characteristic curves and likelihood ratios: improvements over traditional methods for the evaluation and application of veterinary clinical pathology tests

    Gardner, Ian A.; Greiner, Matthias

    2006-01-01

    Receiver-operating characteristic (ROC) curves provide a cutoff-independent method for the evaluation of continuous or ordinal tests used in clinical pathology laboratories. The area under the curve is a useful overall measure of test accuracy and can be used to compare different tests (or...... different equipment) used by the same tester, as well as the accuracy of different diagnosticians that use the same test material. To date, ROC analysis has not been widely used in veterinary clinical pathology studies, although it should be considered a useful complement to estimates of sensitivity...... and specificity in test evaluation studies. In addition, calculation of likelihood ratios can potentially improve the clinical utility of such studies because likelihood ratios provide an indication of how the post-test probability changes as a function of the magnitude of the test results. For ordinal test...

  6. C-reactive protein-to-albumin ratio is a predictor of hepatitis B virus related decompensated cirrhosis: time-dependent receiver operating characteristics and decision curve analysis.

    Huang, Si-Si; Xie, Dong-Mei; Cai, Yi-Jing; Wu, Jian-Min; Chen, Rui-Chong; Wang, Xiao-Dong; Song, Mei; Zheng, Ming-Hua; Wang, Yu-Qun; Lin, Zhuo; Shi, Ke-Qing

    2017-04-01

    Hepatitis B virus (HBV) infection remains a major health problem and HBV-related-decompensated cirrhosis (HBV-DC) usually leads to a poor prognosis. Our aim was to determine the utility of inflammatory biomarkers in predicting mortality of HBV-DC. A total of 329 HBV-DC patients were enrolled. Survival estimates for the entire study population were generated using the Kaplan-Meier method. The prognostic values for model for end-stage liver disease (MELD) score, Child-Pugh score, and inflammatory biomarkers neutrophil/lymphocyte ratio, C-reactive protein-to-albumin ratio (CAR), and lymphocyte-to-monocyte ratio (LMR) for HBV-DC were compared using time-dependent receiver operating characteristic curves and time-dependent decision curves. The survival time was 23.1±15.8 months. Multivariate analysis identified age, CAR, LMR, and platelet count as prognostic independent risk factors. Kaplan-Meier analysis indicated that CAR of at least 1.0 (hazard ratio, 7.19; 95% confidence interval, 4.69-11.03), and LMR less than 1.9 (hazard ratio, 2.40; 95% confidence interval, 1.69-3.41) were independently associated with mortality of HBV-DC. The time-dependent receiver operating characteristic indicated that CAR showed the best performance in predicting mortality of HBV-DC compared with LMR, MELD score, and Child-Pugh score. The results were also confirmed by time-dependent decision curves. CAR and LMR were associated with the prognosis of HBV-DC. CAR was superior to LMR, MELD score, and Child-Pugh score in HBV-DC mortality prediction.

  7. Correlation of free-response and receiver-operating-characteristic area-under-the-curve estimates: Results from independently conducted FROC/ROC studies in mammography

    Zanca, Federica; Hillis, Stephen L.; Claus, Filip; Van Ongeval, Chantal; Celis, Valerie; Provoost, Veerle; Yoon, Hong-Jun; Bosmans, Hilde

    2012-01-01

    Purpose: From independently conducted free-response receiver operating characteristic (FROC) and receiver operating characteristic (ROC) experiments, to study fixed-reader associations between three estimators: the area under the alternative FROC (AFROC) curve computed from FROC data, the area under the ROC curve computed from FROC highest rating data, and the area under the ROC curve computed from confidence-of-disease ratings. Methods: Two hundred mammograms, 100 of which were abnormal, were processed by two image-processing algorithms and interpreted by four radiologists under the FROC paradigm. From the FROC data, inferred-ROC data were derived, using the highest rating assumption. Eighteen months afterwards, the images were interpreted by the same radiologists under the conventional ROC paradigm; conventional-ROC data (in contrast to inferred-ROC data) were obtained. FROC and ROC (inferred, conventional) data were analyzed using the nonparametric area-under-the-curve (AUC), (AFROC and ROC curve, respectively). Pearson correlation was used to quantify the degree of association between the modality-specific AUC indices and standard errors were computed using the bootstrap-after-bootstrap method. The magnitude of the correlations was assessed by comparison with computed Obuchowski-Rockette fixed reader correlations. Results: Average Pearson correlations (with 95% confidence intervals in square brackets) were: Corr(FROC, inferred ROC) = 0.76[0.64, 0.84] > Corr(inferred ROC, conventional ROC) = 0.40[0.18, 0.58] > Corr (FROC, conventional ROC) = 0.32[0.16, 0.46]. Conclusions: Correlation between FROC and inferred-ROC data AUC estimates was high. Correlation between inferred- and conventional-ROC AUC was similar to the correlation between two modalities for a single reader using one estimation method, suggesting that the highest rating assumption might be questionable.

  8. [Optimal Operational Definition of Patient with Peptic Ulcer Bleeding for Big Data Analysis Using Combination of Clinical Characteristics in a Secondary General Hospital].

    Lee, Jae Won; Kim, Hyun Ki; Woo, Yong Sik; Jahng, Jaehoon; Jin, Young Ran; Park, Jong Heon; Kim, Yong Sung; Jung, Hwoon Yong

    2016-08-25

    Peptic ulcer bleeding (PUB) is the most common cause of upper gastrointestinal bleeding in Korea but there has been no research done using big data. This study evaluates the optimal operational definition (OD) for big data research by analyzing clinical characteristics of PUB. We reviewed the clinical characteristics of 92 patients with PUB confirmed on endoscopy in Wonkwang University Sanbon Hospital (January 2013 to December 2014). We calculated sensitivity and positive predictive value (PPV) to detect confirmed PUB patients using ODs developed by combining clinical features of patients with PUB. The mean patient age was 63 years. Men had higher prevalence of PUB than women. Bleeding gastric ulcer was proportionately common in the age range of 40s to 60s in men, while a significantly higher rate of bleeding occurred in women older than 70s. The rate of drug-induced ulcer was 28.2%, whereas the prevalence of Helicobacter pylori was 47.8%. Among the hospitalized patients with diagnostic code of PUB, we ruled out patients with endoscopic removal of gastric adenoma or peritonitis, and selected patients who had been administered intravenous proton pump inhibitor. The sensitivity in this setting was 82.6%, and PPV was 88.4%. PUB was more common in older patients, and there was a clear gender difference in gastric ulcer bleeding by age. With a proper OD using PUB diagnostic codes, we can identify true patients with sufficiently high sensitivity and PPV.

  9. The role of stenosis ratio as a predictor of surgical satisfaction in patients with lumbar spinal canal stenosis: a receiver-operator characteristic (ROC) curve analysis.

    Mohammadi, Hassanreza R; Azimi, Parisa; Benzel, Edward C; Shahzadi, Sohrab; Azhari, Shirzad

    2016-09-01

    The aim of this study was to elucidate independent factors that predict surgical satisfaction in lumbar spinal canal stenosis (LSCS) patients. Patients who underwent surgery were grouped based on the age, gender, duration of symptoms, walking distance, Neurogenic Claudication Outcome Score (NCOS) and the stenosis ratio (SR) described by Lurencin. We recorded on 2-year patient satisfaction using standardized measure. The optimal cut-off points in SR, NCOS and walking distance for predicting surgical satisfaction were estimated from sensitivity and specificity calculations and receiver operator characteristic (ROC) curves. One hundred fifty consecutive patients (51 male, 99 female, mean age 62.4±10.9 years) were followed up for 34±13 months (range 24-49). One, two, three and four level stenosis was observed in 10.7%, 39.3%, 36.0 % and 14.0% of patients, respectively. Post-surgical satisfaction was 78.5% at the 2 years follow up. In ROC curve analysis, the asymptotic significance is less than 0.05 in SR and the optimal cut-off value of SR to predict worsening surgical satisfaction was measured as more than 0.52, with 85.4% sensitivity and 77.4% specificity (AUC 0.798, 95% CI 0.73-0.90; Ppatients with degenerative lumbar stenosis considered for surgical treatment. Using a ROC curve analysis, a radiological feature, the SR, demonstrated superiority in predicting patient satisfaction, compared to functional and clinical characteristics such as walking distance and NCOS.

  10. Effect of S-1 chemotherapy and FP chemotherapy on prognosis, imaging characteristics and serum marker levels after operation for gastric carcinoma

    Qing-Hao Gong

    2016-09-01

    Full Text Available Objective: To analyze the effect of S-1 chemotherapy and FP chemotherapy on prognosis, imaging characteristics and serum marker levels after operation for gastric carcinoma. Methods: A total of 68 patients with gastric cancer who underwent radical surgery were included in the study and divided into observation group and control group patients (n=34 according to random number table. Control group received FP chemotherapy, observation group received S-1 chemotherapy, and then differences in serum tumor markers, illnessrelated factors, nutrition indexes and T cell immune function values were compared between two groups. Results: After observation group received systematic chemotherapy, serum tumor markers such as MMP-9, MMP-2, MG7-Ag, TSGF, CA72-4, CA19-9, TP and DpD as well as illness-related factors such as DKK1, MK, Leptin, Exosome and OPN were all lower than those of control group (P<0.05; nutrition and cellular immune function indexes such as TP, ALB, PA, CD4+ T and CD4+ T/ CD8+ T values were higher than those of control group and CD8+ T value was lower than that of control group (P<0.05. Conclusions: S-1 chemotherapy after operation for gastric carcinoma can inhibit the tumor activity and optimize patients’ overall condition, and it has positive clinical significance.

  11. Performance and emission characteristics of a turbocharged spark-ignition hydrogen-enriched compressed natural gas engine under wide open throttle operating conditions

    Ma, Fanhua; Wang, Mingyue; Jiang, Long; Deng, Jiao; Chen, Renzhe; Naeve, Nashay; Zhao, Shuli [State Key Laboratory of Automotive Safety and Energy, Tsinghua University, Beijing 100084 (China)

    2010-11-15

    This paper investigates the effect of various hydrogen ratios in HCNG (hydrogen-enriched compressed natural gas) fuels on performance and emission characteristics at wide open throttle operating conditions using a turbocharged spark-ignition natural gas engine. The experimental data was taken at hydrogen fractions of 0%, 30% and 55% by volume and was conducted under different excess air ratio ({lambda}) at MBT operating conditions. It is found that under various {lambda}, the addition of hydrogen can significantly reduce CO, CH{sub 4} emissions and the NO{sub x} emission remain at an acceptable level when ignition timing is optimized. Using the same excess air ratio, as more hydrogen is added the power, exhaust temperatures and max cylinder pressure decrease slowly until the mixture's lower heating value remains unchanged with the hydrogen enrichment, then they rise gradually. In addition, the early flame development period and the flame propagation duration are both shorter, and the indicated thermal efficiency and maximum heat release rate both increase with more hydrogen addition. (author)

  12. Effects of a Nano-Silica Additive on the Rock Erosion Characteristics of a SC-CO2 Jet under Various Operating Conditions

    Man Huang

    2017-02-01

    Full Text Available In order to improve the erosion capacity of a supercritical carbon dioxide (SC-CO2 jet, the influence of a nano-silica additive on the rock erosion characteristics was experimentally investigated. By impinging the SC-CO2 jets with nano-silica mass fractions of 0 wt % (pure SC-CO2 jet, 3 wt %, 6 wt %, 9 wt %, 12 wt %, 15 wt %, and 18 wt % on specimens of red sandstone, the erosion volumes under various operating conditions were measured and analyzed. Results show that an appropriate amount of nano-silica additive can greatly enhance the erosion ability of a SC-CO2 jet. The effect on the erosion ability largely depends on the operating conditions. For instance, when the other conditions are fixed, 6 wt %, 9 wt %, 12 wt %, and 15 wt % were the optimum mass fractions, successively, with the inlet pressure increasing from 30 MPa to 60 MPa. With the increase in ambient pressure, the optimum mass fraction is unchanged under the constant inlet pressure, while it increases under the constant pressure drop. Additionally, the optimum mass fraction decreases when the fluid temperature increases. In addition, the optimal standoff distances are about five times the nozzle diameter of the nano-silica SC-CO2 jet, and three times for the pure jet. This research provides a new method for effectively enhancing the rock erosion performance of a SC-CO2 jet.

  13. A systematic review and meta-analysis of studies evaluating the performance and operational characteristics of dual point-of-care tests for HIV and syphilis.

    Gliddon, Harriet D; Peeling, Rosanna W; Kamb, Mary L; Toskin, Igor; Wi, Teodora E; Taylor, Melanie M

    2017-12-01

    Mother-to-child transmission (MTCT) of syphilis and HIV continue to be important yet preventable causes of perinatal and infant morbidity and mortality. To systematically review, critically appraise and perform a meta-analysis to evaluate the operational characteristics of dual rapid diagnostic tests (RDTs) for HIV/syphilis and evaluate whether they are cost effective, acceptable and easy to use. Systematic review and meta-analysis. We searched seven electronic bibliographic databases from 2012 to December 2016 with no language restrictions. Search keywords included HIV, syphilis and diagnosis. We included studies that evaluated the operational characteristics of dual HIV/syphilis RDTs. Outcomes included diagnostic test accuracy, cost effectiveness, ease of use and interpretation and acceptability. All studies were assessed against quality criteria and assessed for risk of bias. Of 1914 identified papers, 18 were included for the meta-analysis of diagnostic accuracy for HIV and syphilis. All diagnostic accuracy evaluation studies showed a very high sensitivity and specificity for HIV and a lower, yet adequate, sensitivity and specificity for syphilis, with some variation among types of test. Dual screening for HIV and syphilis was more cost effective than single rapid tests for HIV and syphilis and prevented more adverse pregnancy outcomes. Qualitative data suggested dual RDTs were highly acceptable to clients, who cited time to result, cost and the requirement of a single finger prick as important characteristics of dual RDTs. The results of this systematic review and meta-analysis can be used by policy-makers and national programme managers who are considering implementing dual RDTs for HIV and syphilis. PROSPERO 2016:CRD42016049168. © World Health Organization 2017. Licensee BMJ Publishing Group Limited. This is an open access article distributed under the terms of the Creative Commons Attribution IGO License (https://creativecommons.org/licenses/by/3.0/igo

  14. The Effect of Operating Conditions on Drying Characteristics and Quality of Ginger (Zingiber Officinale Roscoe) Using Combination of Solar Energy-Molecular Sieve Drying System

    Hasibuan, R.; Zamzami, M. A.

    2017-03-01

    Ginger (Zingiber officinale Roscoe) is an agricultural product that can be used as beverages and snacks, and especially for traditional medicines. One of the important stages in the processing of ginger is drying. The drying process intended to reduce the water content of 85-90% to 8-10%, making it safe from the influence of fungi or insecticide. During the drying takes place, the main ingredient contained in ginger is homologous ketone phenolic known as gingerol are chemically unstable at high temperatures, for the drying technology is an important factor in maintaining the active ingredient (gingerol) which is in ginger. The combination of solar energy and molecular sieve dryer that are used in the research is capable of operating 24 hours. The purpose of this research is to study the effect of operating conditions (in this case the air velocity) toward the drying characteristics and the quality of dried ginger using the combination of solar energy and molecular sieve dryer. Drying system consist of three main parts which is: desiccator, solar collector, and the drying chamber. To record data changes in the mass of the sample, a load cell mounted in the drying chamber, and then connected to the automated data recording system using a USB data cable. All data of temperature and RH inside the dryer box and the change of samples mass recorded during the drying process takes place and the result is stored in the form of Microsoft Excel. The results obtained, shows that the air velocity is influencing the moisture content and ginger drying rate, where the moisture content equilibrium of ginger for the air velocity of 1.3 m/s was obtained on drying time of 360 minutes and moisture content of 2.8%, at 1.0 m/s was obtained on drying time of 300 minutes and moisture content of 1.4%, at 0, 8 m/s was obtained at 420 minutes drying time and the moisture content is 2.0%. The drying characteristics shows that there are two drying periods, which is: the increasing drying rate

  15. Effect of operation conditions of the drop-on-demand aerosol generator on aerosol characteristics: Pseudo-cinematographic and plasma mass spectrometric studies

    Orlandini von Niessen, Jan O.; Krone, Karin M.; Bings, Nicolas H.

    2014-01-01

    The recently presented drop-on-demand (DOD) aerosol generator overcomes some of the drawbacks of pneumatic nebulization, as its aerosol is no longer generated by gas–liquid interaction. In the current study, an advanced imaging technique is presented, based on a CCD camera equipped with magnifying telecentric optics to allow for fast, automated and precise aerosol characterization as well as fundamental studies on the droplet generation processes by means of pseudo-cinematography. The DOD aerosol generator is thoroughly characterized regarding its droplet size distribution, which shows few distinct populations rather than a continuous distribution. Other important figures, such as the Sauter diameter (D 3,2 ) of 22 μm and the span of 0.4 were also determined. Additionally, the influence of the electrical operation conditions of the dosing device on the aerosol generation process is described. The number and volume of the generated droplets were found to be very reproducible and user-variable, e.g. from 17 to 27 μm (D 3,2 ), within a span of 0.07–0.89. The performances of different setups of the DOD as liquid sample introduction system in ICP-MS are correlated to the respective achievable aerosol characteristics and are also compared to the performance of a state-of-the-art μ-flow nebulizer (EnyaMist). The DOD system allowed for improved sensitivity, but slightly elevated signal noise and overall comparable limits of detection. The results are critically discussed and future directions are outlined. - Graphical abstract: Further characterization of the drop-on-demand aerosol generator for sample introduction in atomic spectrometry. - Highlights: • Significantly improved ICP-MS sensitivity using the DOD vs. EnyaMist. • Comparable detection limits but slightly worse short-term precision. • Superior flexibility compared with conventional/miniaturized pneumatic nebulizers. • Electrical operation conditions of the DOD influence aerosol characteristics.

  16. Performance Analysis of an Evaporator for a Diesel Engine–Organic Rankine Cycle (ORC Combined System and Influence of Pressure Drop on the Diesel Engine Operating Characteristics

    Chen Bei

    2015-06-01

    Full Text Available The main purpose of this research is to analyze the performance of an evaporator for the organic Rankine cycle (ORC system and discuss the influence of the evaporator on the operating characteristics of diesel engine. A simulation model of fin-and-tube evaporator of the ORC system is established by using Fluent software. Then, the flow and heat transfer characteristics of the exhaust at the evaporator shell side are obtained, and then the performance of the fin-and-tube evaporator of the ORC system is analyzed based on the field synergy principle. The field synergy angle (β is the intersection angle between the velocity vector and the temperature gradient. When the absolute values of velocity and temperature gradient are constant and β < 90°, heat transfer enhancement can be achieved with the decrease of the β. When the absolute values of velocity and temperature gradient are constant and β >90°, heat transfer enhancement can be achieved with the increase of the β. Subsequently, the influence of the evaporator of the ORC system on diesel engine performance is studied. A simulation model of the diesel engine is built by using GT–Power software under various operating conditions, and the variation tendency of engine power, torque, and brake specific fuel consumption (BSFC are obtained. The variation tendency of the power output and BSFC of diesel engine–ORC combined system are obtained when the evaporation pressure ranges from 1.0 MPa to 3.5 MPa. Results show that the field synergy effect for the areas among the tube bundles of the evaporator main body and the field synergy effect for the areas among the fins on the windward side are satisfactory. However, the field synergy effect in the areas among the fins on the leeward side is weak. As a result of the pressure drop caused by the evaporator of the ORC system, the diesel engine power and torque decreases slightly, whereas the BSFC increases slightly with the increase of exhaust back

  17. Effect of operation conditions of the drop-on-demand aerosol generator on aerosol characteristics: Pseudo-cinematographic and plasma mass spectrometric studies

    Orlandini von Niessen, Jan O.; Krone, Karin M.; Bings, Nicolas H., E-mail: bings@uni-mainz.de

    2014-02-01

    The recently presented drop-on-demand (DOD) aerosol generator overcomes some of the drawbacks of pneumatic nebulization, as its aerosol is no longer generated by gas–liquid interaction. In the current study, an advanced imaging technique is presented, based on a CCD camera equipped with magnifying telecentric optics to allow for fast, automated and precise aerosol characterization as well as fundamental studies on the droplet generation processes by means of pseudo-cinematography. The DOD aerosol generator is thoroughly characterized regarding its droplet size distribution, which shows few distinct populations rather than a continuous distribution. Other important figures, such as the Sauter diameter (D{sub 3,2}) of 22 μm and the span of 0.4 were also determined. Additionally, the influence of the electrical operation conditions of the dosing device on the aerosol generation process is described. The number and volume of the generated droplets were found to be very reproducible and user-variable, e.g. from 17 to 27 μm (D{sub 3,2}), within a span of 0.07–0.89. The performances of different setups of the DOD as liquid sample introduction system in ICP-MS are correlated to the respective achievable aerosol characteristics and are also compared to the performance of a state-of-the-art μ-flow nebulizer (EnyaMist). The DOD system allowed for improved sensitivity, but slightly elevated signal noise and overall comparable limits of detection. The results are critically discussed and future directions are outlined. - Graphical abstract: Further characterization of the drop-on-demand aerosol generator for sample introduction in atomic spectrometry. - Highlights: • Significantly improved ICP-MS sensitivity using the DOD vs. EnyaMist. • Comparable detection limits but slightly worse short-term precision. • Superior flexibility compared with conventional/miniaturized pneumatic nebulizers. • Electrical operation conditions of the DOD influence aerosol

  18. Operation amplifier

    Tetsuya, Saito; Nauta, Bram

    2008-01-01

    To provide an operation amplifier which improves power source voltage removal ratios while assuring phase compensation characteristics, and therefore can be realized with a small-scale circuit and low power consumption. SOLUTION: The operation amplifier comprises: a differential amplifier circuit 1;

  19. Operation Amplifier

    Tetsuya, Saito; Nauta, Bram

    2011-01-01

    PROBLEM TO BE SOLVED: To provide an operation amplifier which improves power source voltage removal ratios while assuring phase compensation characteristics, and therefore can be realized with a small-scale circuit and low power consumption. SOLUTION: The operation amplifier comprises: a

  20. Operation Amplifier

    Tetsuya, S.; Nauta, Bram

    2007-01-01

    PROBLEM TO BE SOLVED: To provide an operation amplifier which improves power source voltage removal ratios while assuring phase compensation characteristics, and therefore can be realized with a small-scale circuit and low power consumption. ; SOLUTION: The operation amplifier comprises: a

  1. Spatial and temporal characteristics of warm season convection over Pearl River Delta region, China, based on 3 years of operational radar data

    Chen, Xingchao; Zhao, Kun; Xue, Ming

    2014-11-01

    This study examines the temporal and spatial characteristics and distributions of convection over the Pearl River Delta region of Guangzhou, China, during the May-September warm season, using, for the first time for such a purpose, 3 years of operational Doppler radar data in the region. Results show that convective features occur most frequently along the southern coast and the windward slope of the eastern mountainous area of Pearl River Delta, with the highest frequency occurring in June and the lowest in September among the 5 months. The spatial frequency distribution pattern also roughly matches the accumulated precipitation pattern. The occurrence of convection in this region also exhibits strong diurnal cycles. During May and June, the diurnal distribution is bimodal, with the maximum frequency occurring in the early afternoon and a secondary peak occurring between midnight and early morning. The secondary peak is much weaker in July, August, and September. Convection near the coast is found to occur preferentially on days when a southerly low-level jet (LLJ) exists, especially during the Meiyu season. Warm, moist, and unstable air is transported from the ocean to land by LLJs on these days, and the lifting along the coast by convergence induced by differential surface friction between the land and ocean is believed to be the primary cause for the high frequency along the coast. In contrast, the high frequency over mountainous area is believed to be due to orographic lifting of generally southerly flows during the warm season.

  2. Evaluation of the optimal diagnostic criteria for regional lymph node metastases of lung cancer on MR imaging by receiver operating characteristic curve

    Iwai, Naomichi; Yamaguchi, Yutaka

    1991-01-01

    MRI was performed in 78 primary lung cancer cases to evaluate the optimal diagnostic criteria for regional lymph node metastases. Receiver operating characteristic (ROC) curve analysis for 262 lymph nodes of the hilar and mediastinal regions showed that the optimal size criterion is 10 mm in the mean axis of nodal diameter. Employing this criterion, the diagnostic rates for hilar and mediastinal lymph nodes had a sensitivity of 75%, a specificity of 82%, and an overall accuracy of 79%. However, the diagnostic rates for subaortic, paraaortic, and hilar lymph nodes using the same criterion showed lower specificities than those for other nodes. It was suggested that evaluation by coronal section made the diagnosis for subaortic lymph nodes more precise. In the ROC curve analysis for each histologic type, it was thought that the optimal criterion for adenocarcinoma was 10 mm in the mean axis, and that the criteria for squamous cell carcinoma were 11 mm in the mean axis and 10 mm in the sort axis. (author)

  3. Comparing the role of selective and divided attention in the composite face effect: Insights from Attention Operating Characteristic (AOC) plots and cross-contingency correlations.

    Fitousi, Daniel

    2016-03-01

    Composite faces combine the top half of one face with the bottom half of another to create a compelling illusion of a new face. Evidence for holistic processing with composite faces comes primarily from a matching procedure in a selective attention task. In the present study, a dual-task approach has been employed to study whether composite faces reflect genuine holistic (i.e., fusion of parts) or non-holistic processing strategies (i.e., switching, resource sharing). This has been accomplished by applying the Attention Operation Characteristic methodology (AOC, Sperling & Melchner, 1978a, 1978b) and cross-contingency correlations (Bonnel & Prinzmetal, 1998) to composite faces. Overall, the results converged on the following conclusions: (a) observers can voluntarily allocate differential amounts of attention to the top and bottom parts in both spatially aligned and misaligned composite faces, (b) the interaction between composite face halves is due to attentional limitations, not due to switching or fusion strategies, and (c) the processing of aligned and misaligned composite faces is quantitatively and qualitatively similar. Taken together, these results challenge the holistic interpretation of the composite face illusion. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Oxide Structure Dependence of SiO2/SiOx/3C-SiC/n-Type Si Nonvolatile Resistive Memory on Memory Operation Characteristics

    Yamaguchi, Yuichiro; Shouji, Masatsugu; Suda, Yoshiyuki

    2012-11-01

    We have investigated the dependence of the oxide layer structure of our previously proposed metal/SiO2/SiOx/3C-SiC/n-Si/metal metal-insulator-semiconductor (MIS) resistive memory device on the memory operation characteristics. The current-voltage (I-V) measurement and X-ray photoemission spectroscopy results suggest that SiOx defect states mainly caused by the oxidation of 3C-SiC at temperatures below 1000 °C are related to the hysteresis memory behavior in the I-V curve. By restricting the SiOx interface region, the number of switching cycles and the on/off current ratio are more enhanced. Compared with a memory device formed by one-step or two-step oxidation of 3C-SiC, a memory device formed by one-step oxidation of Si/3C-SiC exhibits a more restrictive SiOx interface with a more definitive SiO2 layer and higher memory performances for both the endurance switching cycle and on/off current ratio.

  5. Sex differences in the prediction of the effectiveness of paroxetine for patients with major depressive disorder identified using a receiver operating characteristic curve analysis for early response.

    Tomita, Tetsu; Yasui-Furukori, Norio; Norio, Yasui-Furukori; Sato, Yasushi; Nakagami, Taku; Tsuchimine, Shoko; Kaneda, Ayako; Kaneko, Sunao

    2014-01-01

    We investigated cutoff values for the early response of patients with major depressive disorder to paroxetine and their sex differences by using a receiver operating characteristic (ROC) curve analysis to predict the effectiveness of paroxetine. In total, 120 patients with major depressive disorder were enrolled and treated with 10-40 mg/day paroxetine for 6 weeks; 89 patients completed the protocol. A clinical evaluation using the Montgomery-Asberg Depression Rating Scale (MADRS) was performed at weeks 0, 1, 2, 4, and 6. In male subjects, the cutoff values for MADRS improvement rating in week 1, week 2, and week 4 were 20.9%, 34.9%, and 33.3%, respectively. The sensitivities and the specificities were 83.3% and 80.0%, 83.3% and 80.0%, and 100% and 90%, respectively. The areas under the curve (AUC) were 0.908, 0.821, and 0.979, respectively. In female subjects, the cutoff values for the MADRS improvement rating in week 1, week 2, and week 4 were 21.4%, 35.7%, and 32.3%, respectively. The sensitivities and the specificities were 71.4% and 84.6%, 73.8% and 76.9%, and 90.5% and 76.9%, respectively. The AUCs were 0.781, 0.735, and 0.904, respectively. Early improvement with paroxetine may predict the long-term response. The accuracy of the prediction for the response is higher in male subjects.

  6. Disadvantages of using the area under the receiver operating characteristic curve to assess imaging tests: A discussion and proposal for an alternative approach

    Halligan, Steve; Altman, Douglas G.; Mallett, Susan

    2015-01-01

    The objectives are to describe the disadvantages of the area under the receiver operating characteristic curve (ROC AUC) to measure diagnostic test performance and to propose an alternative based on net benefit. We use a narrative review supplemented by data from a study of computer-assisted detection for CT colonography. We identified problems with ROC AUC. Confidence scoring by readers was highly non-normal, and score distribution was bimodal. Consequently, ROC curves were highly extrapolated with AUC mostly dependent on areas without patient data. AUC depended on the method used for curve fitting. ROC AUC does not account for prevalence or different misclassification costs arising from false-negative and false-positive diagnoses. Change in ROC AUC has little direct clinical meaning for clinicians. An alternative analysis based on net benefit is proposed, based on the change in sensitivity and specificity at clinically relevant thresholds. Net benefit incorporates estimates of prevalence and misclassification costs, and it is clinically interpretable since it reflects changes in correct and incorrect diagnoses when a new diagnostic test is introduced. ROC AUC is most useful in the early stages of test assessment whereas methods based on net benefit are more useful to assess radiological tests where the clinical context is known. Net benefit is more useful for assessing clinical impact. (orig.)

  7. Perspective Biological Markers for Autism Spectrum Disorders: Advantages of the Use of Receiver Operating Characteristic Curves in Evaluating Marker Sensitivity and Specificity

    Provvidenza M. Abruzzo

    2015-01-01

    Full Text Available Autism Spectrum Disorders (ASD are a heterogeneous group of neurodevelopmental disorders. Recognized causes of ASD include genetic factors, metabolic diseases, toxic and environmental factors, and a combination of these. Available tests fail to recognize genetic abnormalities in about 70% of ASD children, where diagnosis is solely based on behavioral signs and symptoms, which are difficult to evaluate in very young children. Although it is advisable that specific psychotherapeutic and pedagogic interventions are initiated as early as possible, early diagnosis is hampered by the lack of nongenetic specific biological markers. In the past ten years, the scientific literature has reported dozens of neurophysiological and biochemical alterations in ASD children; however no real biomarker has emerged. Such literature is here reviewed in the light of Receiver Operating Characteristic (ROC analysis, a very valuable statistical tool, which evaluates the sensitivity and the specificity of biomarkers to be used in diagnostic decision making. We also apply ROC analysis to some of our previously published data and discuss the increased diagnostic value of combining more variables in one ROC curve analysis. We also discuss the use of biomarkers as a tool for advancing our understanding of nonsyndromic ASD.

  8. Operation characteristic of a heat pump of mechanical vapor recompression propelled by fans and its performance analysis applied to waste-water treatment

    Weike, Pang; Wenju, Lin; Qilin, Pan; Wenye, Lin; Qunte, Dai; Luwei, Yang; Zhentao, Zhang

    2014-01-01

    In this paper, a set of heat pump (called as Mechanical Vapor Recompression, MVR) propelled by a centrifugal fan is tested and it shows some special characteristic when it works together with a falling film evaporator. Firstly, an analysis of the fan's suction and discharge parameters at stable state, such as its pressure and temperature, indicates that a phenomenon of wet compression is probably to appear during vapor compression. As a result, superheat after saturated vapor is compressed is eliminated, which reduces discharge temperature of the system. It is because drops boil away and absorb the super heat into their latent heat during vapor compression. Meanwhile, drops in the suction vapor add to the compressed vapor, which increase the given heat of the MVR heat pump. Next, assistant electric heat could adjust and keep steady of the operating pressure and temperature of an MVR heat pump. With the evaporation temperature up to be high, heat balance is broken and supplement heat needs to increase. Thirdly, the performance of an MVR heat pump is affect by the balance of falling film and evaporation that has an effect on heat transfer. Then, two parameters standing for the performance are measured as it runs in practical condition. The two important parameters are consumptive electricity power and productive water capacity. According to theoretical work in ideal condition by calculation and fan's input power by measure as running, adiabatic efficiency (ηad) of a centrifugal fan is calculated when it is applied in a heat pump of MVR. Following, based on ηad, practical SMER and COP of an MVR heat pump are discovered to be correlative with it. Finally, in dependence on productive water in theory and in practice, displacement efficiency (ηv) of centrifugal fans is obtained when compressing vapor, and so provide some references of matching a fan for an MVR heat pump. On the other hand, it is helpful to research and develop MVR heat pumps, and also to check

  9. Delineating a Retesting Zone Using Receiver Operating Characteristic Analysis on Serial QuantiFERON Tuberculosis Test Results in US Healthcare Workers

    Wendy Thanassi

    2012-01-01

    Full Text Available Objective. To find a statistically significant separation point for the QuantiFERON Gold In-Tube (QFT interferon gamma release assay that could define an optimal “retesting zone” for use in serially tested low-risk populations who have test “reversions” from initially positive to subsequently negative results. Method. Using receiver operating characteristic analysis (ROC to analyze retrospective data collected from 3 major hospitals, we searched for predictors of reversion until statistically significant separation points were revealed. A confirmatory regression analysis was performed on an additional sample. Results. In 575 initially positive US healthcare workers (HCWs, 300 (52.2% had reversions, while 275 (47.8% had two sequential positive tests. The most statistically significant (Kappa = 0.48, chi-square = 131.0, P<0.001 separation point identified by the ROC for predicting reversion was the tuberculosis antigen minus-nil (TBag-nil value at 1.11 International Units per milliliter (IU/mL. The second separation point was found at TBag-nil at 0.72 IU/mL (Kappa = 0.16, chi-square = 8.2, P<0.01. The model was validated by the regression analysis of 287 HCWs. Conclusion. Reversion likelihood increases as the TBag-nil approaches the manufacturer's cut-point of 0.35 IU/mL. The most statistically significant separation point between those who test repeatedly positive and those who revert is 1.11 IU/mL. Clinicians should retest low-risk individuals with initial QFT results < 1.11 IU/mL.

  10. Mapping crop based on phenological characteristics using time-series NDVI of operational land imager data in Tadla irrigated perimeter, Morocco

    Ouzemou, Jamal-eddine; El Harti, Abderrazak; EL Moujahid, Ali; Bouch, Naima; El Ouazzani, Rabii; Lhissou, Rachid; Bachaoui, El Mostafa

    2015-10-01

    Morocco is a primarily arid to semi-arid country. These climatic conditions make irrigation an imperative and inevitable technique. Especially, agriculture has a paramount importance for the national economy. Retrieving of crops and their location as well as their spatial extent is useful information for agricultural planning and better management of irrigation water resource. Remote sensing technology was often used in management and agricultural research. Indeed, it's allows crops extraction and mapping based on phenological characteristics, as well as yield estimation. The study area of this work is the Tadla irrigated perimeter which is characterized by heterogeneous areas and extremely small size fields. Our principal objectives are: (1) the delimitation of the major crops for a good water management, (2) the insulation of sugar beet parcels for modeling its yields. To achieve the traced goals, we have used Landsat-8 OLI (Operational Land Imager) data pan-sharpened to 15 m. Spectral Angle Mapper (SAM) and Support Vector Machine (SVM) classifications were applied to the Normalized Difference Vegetation Index (NDVI) time-series of 10 periods. Classifications were calculated for a site of more than 124000 ha. This site was divided into two parts: the first part for selecting, training datasets and the second one for validating the classification results. The SVM and SAM methods classified the principal crops with overall accuracies of 85.27% and 57.17% respectively, and kappa coefficient of 80% and 43% respectively. The study showed the potential of using time-series OLI NDVI data for mapping different crops in irrigated, heterogeneous and undersized parcels in arid and semi-arid environment.

  11. Task-based detectability comparison of exponential transformation of free-response operating characteristic (EFROC) curve and channelized Hotelling observer (CHO)

    Khobragade, P.; Fan, Jiahua; Rupcich, Franco; Crotty, Dominic J.; Gilat Schmidt, Taly

    2016-03-01

    This study quantitatively evaluated the performance of the exponential transformation of the free-response operating characteristic curve (EFROC) metric, with the Channelized Hotelling Observer (CHO) as a reference. The CHO has been used for image quality assessment of reconstruction algorithms and imaging systems and often it is applied to study the signal-location-known cases. The CHO also requires a large set of images to estimate the covariance matrix. In terms of clinical applications, this assumption and requirement may be unrealistic. The newly developed location-unknown EFROC detectability metric is estimated from the confidence scores reported by a model observer. Unlike the CHO, EFROC does not require a channelization step and is a non-parametric detectability metric. There are few quantitative studies available on application of the EFROC metric, most of which are based on simulation data. This study investigated the EFROC metric using experimental CT data. A phantom with four low contrast objects: 3mm (14 HU), 5mm (7HU), 7mm (5 HU) and 10 mm (3 HU) was scanned at dose levels ranging from 25 mAs to 270 mAs and reconstructed using filtered backprojection. The area under the curve values for CHO (AUC) and EFROC (AFE) were plotted with respect to different dose levels. The number of images required to estimate the non-parametric AFE metric was calculated for varying tasks and found to be less than the number of images required for parametric CHO estimation. The AFE metric was found to be more sensitive to changes in dose than the CHO metric. This increased sensitivity and the assumption of unknown signal location may be useful for investigating and optimizing CT imaging methods. Future work is required to validate the AFE metric against human observers.

  12. Use of systems pharmacology modeling to elucidate the operating characteristics of SGLT1 and SGLT2 in renal glucose reabsorption in humans.

    Lu, Yasong; Griffen, Steven C; Boulton, David W; Leil, Tarek A

    2014-01-01

    In the kidney, glucose in glomerular filtrate is reabsorbed primarily by sodium-glucose cotransporters 1 (SGLT1) and 2 (SGLT2) along the proximal tubules. SGLT2 has been characterized as a high capacity, low affinity pathway responsible for reabsorption of the majority of filtered glucose in the early part of proximal tubules, and SGLT1 reabsorbs the residual glucose in the distal part. Inhibition of SGLT2 is a viable mechanism for removing glucose from the body and improving glycemic control in patients with diabetes. Despite demonstrating high levels (in excess of 80%) of inhibition of glucose transport by SGLT2 in vitro, potent SGLT2 inhibitors, e.g., dapagliflozin and canagliflozin, inhibit renal glucose reabsorption by only 30-50% in clinical studies. Hypotheses for this apparent paradox are mostly focused on the compensatory effect of SGLT1. The paradox has been explained and the role of SGLT1 demonstrated in the mouse, but direct data in humans are lacking. To further explore the roles of SGLT1/2 in renal glucose reabsorption in humans, we developed a systems pharmacology model with emphasis on SGLT1/2 mediated glucose reabsorption and the effects of SGLT2 inhibition. The model was calibrated using robust clinical data in the absence or presence of dapagliflozin (DeFronzo et al., 2013), and evaluated against clinical data from the literature (Mogensen, 1971; Wolf et al., 2009; Polidori et al., 2013). The model adequately described all four data sets. Simulations using the model clarified the operating characteristics of SGLT1/2 in humans in the healthy and diabetic state with or without SGLT2 inhibition. The modeling and simulations support our proposition that the apparent moderate, 30-50% inhibition of renal glucose reabsorption observed with potent SGLT2 inhibitors is a combined result of two physiological determinants: SGLT1 compensation and residual SGLT2 activity. This model will enable in silico inferences and predictions related to SGLT1/2 modulation.

  13. Effect of light-emitting diode vs. fluorescent lighting on laying hens in aviary hen houses: Part 1 - Operational characteristics of lights and production traits of hens.

    Long, H; Zhao, Y; Wang, T; Ning, Z; Xin, H

    2016-01-01

    Light-emitting diode (LED) lights are becoming more affordable for agricultural applications. Despite many lab-scale studies concerning impact of LED on poultry, little research has been documented under field production conditions, especially for laying hens. This 15-month field study was carried out to evaluate the effects of LED vs. fluorescent (FL) lights on laying hens (Dekalb white breed) using 4 (2 pairs) aviary hen houses each at a nominal capacity of 50,000 hens. The evaluation was done regarding operational characteristics of the lights and hen production traits. The results show that spatial distribution of the LED light was less uniform than that of the FL light. Light intensity of the LED light decreased by 27% after 3,360 h use but remained quite steady from 3,360 to 5,760 h use. Eleven out of 762 (1.44%) LED lamps (new at onset of the study) in the 2 houses failed during the 15-month experiment period. The neck area of the LED lamp was hottest, presumably the primary reason for the lamp failure as cracks were noticed in the neck region of all failed LED lamps. No differences were observed in egg weight, hen-day egg production, feed use, and mortality rate between LED and FL regimens. However, hens under the FL had higher eggs per hen housed and better feed conversion than those under the LED during 20 to 70 wk production (P Hens under the LED tended to have less feather uniformity and insulation than those under the FL (P hens under the LED showed a larger median avoidance distance than those under the FL at 36 wk age (P hens under the LED were more alert; but no difference at 60 wk age. More comparative research to quantify behavioral and production responses of different breeds of hens to LED vs. FL lighting seems warranted. © 2015 Poultry Science Association Inc.

  14. Predicting need for orthognathic surgery in early permanent dentition patients with unilateral cleft lip and palate using receiver operating characteristic analysis.

    Yun-Chia Ku, Michelle; Lo, Lun-Jou; Chen, Min-Chi; Wen-Ching Ko, Ellen

    2018-03-01

    The purpose of this study was to predict the need for orthognathic surgery in patients with unilateral cleft lip and palate (UCLP) in the early permanent dentition. In this retrospective cohort study, we included 61 patients with complete UCLP (36 male, 25 female; mean age, 18.47 years; range, 16.92-26.17 years). The subjects were grouped into an orthognathic surgery group and a nonsurgery group at the time of growth completion. Lateral cephalograms obtained at the age of 11 years were analyzed to compare the 2 groups. The receiver operating characteristic analysis was applied to predict the probability of the need for orthognathic surgery in early adulthood by using the measurements obtained at the age of 11 years. SNB, ANB, SN, overbite, overjet, maxillary length, mandibular body length, and L1-MP were found to be significantly different between the 2 groups. For a person with a score of 2 in the 3-variable-based criteria, the sensitivity and specificity for determining the need for surgical treatment were 90.0% and 83.9%, respectively (ANB, ≤-0.45°; overjet, ≤-2.00 mm; maxillary length, ≤47.25 mm). Three cephalometric variables, the minimum number of discriminators required to obtain the optimum discriminant effectiveness, predicted the future need for orthognathic surgery with an accuracy of 86.9% in patients with UCLP. Copyright © 2017 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  15. DTI measures identify mild and moderate TBI cases among patients with complex health problems: A receiver operating characteristic analysis of U.S. veterans.

    Main, Keith L; Soman, Salil; Pestilli, Franco; Furst, Ansgar; Noda, Art; Hernandez, Beatriz; Kong, Jennifer; Cheng, Jauhtai; Fairchild, Jennifer K; Taylor, Joy; Yesavage, Jerome; Wesson Ashford, J; Kraemer, Helena; Adamson, Maheen M

    2017-01-01

    Standard MRI methods are often inadequate for identifying mild traumatic brain injury (TBI). Advances in diffusion tensor imaging now provide potential biomarkers of TBI among white matter fascicles (tracts). However, it is still unclear which tracts are most pertinent to TBI diagnosis. This study ranked fiber tracts on their ability to discriminate patients with and without TBI. We acquired diffusion tensor imaging data from military veterans admitted to a polytrauma clinic (Overall n  = 109; Age: M  = 47.2, SD  = 11.3; Male: 88%; TBI: 67%). TBI diagnosis was based on self-report and neurological examination. Fiber tractography analysis produced 20 fiber tracts per patient. Each tract yielded four clinically relevant measures (fractional anisotropy, mean diffusivity, radial diffusivity, and axial diffusivity). We applied receiver operating characteristic (ROC) analyses to identify the most diagnostic tract for each measure. The analyses produced an optimal cutpoint for each tract. We then used kappa coefficients to rate the agreement of each cutpoint with the neurologist's diagnosis. The tract with the highest kappa was most diagnostic. As a check on the ROC results, we performed a stepwise logistic regression on each measure using all 20 tracts as predictors. We also bootstrapped the ROC analyses to compute the 95% confidence intervals for sensitivity, specificity, and the highest kappa coefficients. The ROC analyses identified two fiber tracts as most diagnostic of TBI: the left cingulum (LCG) and the left inferior fronto-occipital fasciculus (LIF). Like ROC, logistic regression identified LCG as most predictive for the FA measure but identified the right anterior thalamic tract (RAT) for the MD, RD, and AD measures. These findings are potentially relevant to the development of TBI biomarkers. Our methods also demonstrate how ROC analysis may be used to identify clinically relevant variables in the TBI population.

  16. Effect of operation conditions of the drop-on-demand aerosol generator on aerosol characteristics: Pseudo-cinematographic and plasma mass spectrometric studies

    Orlandini v. Niessen, Jan O.; Krone, Karin M.; Bings, Nicolas H.

    2014-02-01

    The recently presented drop-on-demand (DOD) aerosol generator overcomes some of the drawbacks of pneumatic nebulization, as its aerosol is no longer generated by gas-liquid interaction. In the current study, an advanced imaging technique is presented, based on a CCD camera equipped with magnifying telecentric optics to allow for fast, automated and precise aerosol characterization as well as fundamental studies on the droplet generation processes by means of pseudo-cinematography. The DOD aerosol generator is thoroughly characterized regarding its droplet size distribution, which shows few distinct populations rather than a continuous distribution. Other important figures, such as the Sauter diameter (D3,2) of 22 μm and the span of 0.4 were also determined. Additionally, the influence of the electrical operation conditions of the dosing device on the aerosol generation process is described. The number and volume of the generated droplets were found to be very reproducible and user-variable, e.g. from 17 to 27 μm (D3,2), within a span of 0.07-0.89. The performances of different setups of the DOD as liquid sample introduction system in ICP-MS are correlated to the respective achievable aerosol characteristics and are also compared to the performance of a state-of-the-art μ-flow nebulizer (EnyaMist). The DOD system allowed for improved sensitivity, but slightly elevated signal noise and overall comparable limits of detection. The results are critically discussed and future directions are outlined.

  17. High-fidelity simulation of turbofan engine. ; Verification and improvement of model's dynamical characteristics in linear operating range. Turbofan engine no koseito simulation. ; Senkei sado han'i ni okeru model dotokusei no kensho to seido kojo ni tsuite

    Yamane, H; Kagiyama, S [Defence Agency, Tokyo (Japan)

    1993-09-25

    This paper describes providing pulse inputs to a fuel supply in trial operation of a turbofan engine, measurement of its response, and calculation of the frequency characteristics and time constants to acquire dynamic characteristics of the engine on the ground. The resultant engine characteristics were compared with the model characteristics of numerically analyzing a mathematical simulation model, and corrected to develop a high-accuracy simulation model. An element model and a dynamics model were prepared in detail on the main engine components, such as fans, a compressor, a combustor, and a turbine, along a flow diagram from the air intake opening to the exhaust nozzle. The pulses were inputted into the fuel supply by opening and closing an electromagnetic valve. Closing of the illustrated electromagnetic valve for about 0.7 second caused a difference (of phase and trend) in both characteristics of high and low frequencies as a result of pulse-like change in the flow rate. To correct the model characteristics, the combustion delay tie was set to 0.02 second upon considering the combustion delay time relative to the heat capacity of the combustor. Improvement in the model was verified as the phase characteristics was approximated to the engine characteristics. 13 refs., 17 figs., 2 tabs.

  18. Use systems pharmacology modeling to elucidate the operating characteristics of SGLT1 and SGLT2 in renal glucose reabsorption in humans

    Yasong eLu

    2014-12-01

    Full Text Available In the kidney, glucose in glomerular filtrate is reabsorbed primarily by sodium-glucose cotransporters 1 (SGLT1 and 2 (SGLT2 along the proximal tubules. SGLT2 has been characterized as a high capacity, low affinity pathway responsible for reabsorption of the majority of filtered glucose in the early part of proximal tubules, and SGLT1 reabsorbs the residual glucose in the distal part. Inhibition of SGLT2 is a viable mechanism for removing glucose from the body and improving glycemic control in patients with diabetes. Despite demonstrating high levels (in excess of 80% of inhibition of glucose transport by SGLT2 in vitro, potent SGLT2 inhibitors, e.g., dapagliflozin and canagliflozin, inhibit renal glucose reabsorption by only 30-50% in clinical studies. Hypotheses for this apparent paradox are mostly focused on the compensatory effect of SGLT1. The paradox has been explained and the role of SGLT1 demonstrated in the mouse, but direct data in humans are lacking. To further explore the roles of SGLT1/2 in renal glucose reabsorption in humans, we developed a systems pharmacology model with emphasis on SGLT1/2 mediated glucose reabsorption and the effects of SGLT2 inhibition. The model was calibrated using robust clinical data in the absence or presence of dapagliflozin (DeFronzo et al. data (2013, and evaluated against clinical data from the literature (Mogensen, 1971;Wolf et al., 2009;Polidori et al., 2013. The model adequately described all four data sets. Simulations using the model clarified the operating characteristics of SGLT1/2 in humans in the healthy and diabetic state with or without SGLT2 inhibition. The modeling and simulations support our proposition that the apparent moderate, 30-50% inhibition of renal glucose reabsorption observed with potent SGLT2 inhibitors is a combined result of two physiological determinants: SGLT1 compensation and residual SGLT2 activity. This model will enable in silico inferences and predictions related to

  19. Use of systems pharmacology modeling to elucidate the operating characteristics of SGLT1 and SGLT2 in renal glucose reabsorption in humans

    Lu, Yasong; Griffen, Steven C.; Boulton, David W.; Leil, Tarek A.

    2014-01-01

    In the kidney, glucose in glomerular filtrate is reabsorbed primarily by sodium-glucose cotransporters 1 (SGLT1) and 2 (SGLT2) along the proximal tubules. SGLT2 has been characterized as a high capacity, low affinity pathway responsible for reabsorption of the majority of filtered glucose in the early part of proximal tubules, and SGLT1 reabsorbs the residual glucose in the distal part. Inhibition of SGLT2 is a viable mechanism for removing glucose from the body and improving glycemic control in patients with diabetes. Despite demonstrating high levels (in excess of 80%) of inhibition of glucose transport by SGLT2 in vitro, potent SGLT2 inhibitors, e.g., dapagliflozin and canagliflozin, inhibit renal glucose reabsorption by only 30–50% in clinical studies. Hypotheses for this apparent paradox are mostly focused on the compensatory effect of SGLT1. The paradox has been explained and the role of SGLT1 demonstrated in the mouse, but direct data in humans are lacking. To further explore the roles of SGLT1/2 in renal glucose reabsorption in humans, we developed a systems pharmacology model with emphasis on SGLT1/2 mediated glucose reabsorption and the effects of SGLT2 inhibition. The model was calibrated using robust clinical data in the absence or presence of dapagliflozin (DeFronzo et al., 2013), and evaluated against clinical data from the literature (Mogensen, 1971; Wolf et al., 2009; Polidori et al., 2013). The model adequately described all four data sets. Simulations using the model clarified the operating characteristics of SGLT1/2 in humans in the healthy and diabetic state with or without SGLT2 inhibition. The modeling and simulations support our proposition that the apparent moderate, 30–50% inhibition of renal glucose reabsorption observed with potent SGLT2 inhibitors is a combined result of two physiological determinants: SGLT1 compensation and residual SGLT2 activity. This model will enable in silico inferences and predictions related to SGLT1

  20. Operating Characteristics of a Tuberculosis Screening Tool for People Living with HIV in Out-Patient HIV Care and Treatment Services, Rwanda.

    Kenneth Turinawe

    Full Text Available The World Health Organization (WHO 2010 guidelines for intensified tuberculosis (TB case finding (ICF among people living with HIV (PLHIV includes a recommendation that PLHIV receive routine TB screening. Since 2005, the Rwandan Ministry of Health has been using a five-question screening tool. Our study objective was to assess the operating characteristics of the tool designed to identify PLHIV with presumptive TB as measured against a composite reference standard, including bacteriologically confirmed TB.In a cross-sectional study, the TB screening tool was routinely administered at enrolment in outpatient HIV care and treatment services at seven public health facilities. From March to September 2011, study enrollees were examined for TB disease irrespective of TB screening outcome. The examination consisted of a chest radiograph (CXR, three sputum smears (SS, sputum culture (SC and polymerase chain reaction line-probe assay (Hain test. PLHIV were classified as having "laboratory-confirmed TB" with positive results on SS for acid-fast bacilli, SC on Lowenstein-Jensen medium, or a Hain test.Overall, 1,767 patients were enrolled and screened of which; 1,017 (57.6% were female, median age was 33 (IQR, 27-41, and median CD4+ cell count was 385 (IQR, 229-563 cells/mm3. Of the patients screened, 138 (7.8% were diagnosed with TB of which; 125 (90.5% were laboratory-confirmed pulmonary TB. Of 404 (22.9% patients who screened positive and 1,363 (77.1% who screened negative, 79 (19.5% and 59 (4.3%, respectively, were diagnosed with TB. For laboratory-confirmed TB, the tool had a sensitivity of 54.4% (95% CI 45.3-63.3, specificity of 79.5% (95% CI 77.5-81.5, PPV of 16.8% and NPV of 95.8%.TB prevalence among PLHIV newly enrolling into HIV care and treatment was 65 times greater than the overall population prevalence. However, the performance of the tool was poorer than the predicted performance of the WHO recommended TB screening questions.

  1. Pre-operative assessment of cancer in the elderly (PACE) : A comprehensive assessment of underlying characteristics of elderly cancer patients prior to elective surgery

    Pope, D.; Ramesh, H.; Gennari, R.; Corsini, G.; Maffezzini, M.; Hoekstra, H. J.; Mobarak, D.; Sunouchi, K.; Stotter, A.; West, C.; Audisio, R. A.

    2006-01-01

    Background: Cancer is a disease that particularly affects the elderly and, although surgery is the first treatment choice, many elderly cancer patients do not receive standard surgery because they are considered unfit for treatment due to an inaccurate estimation of operative risk. Pre-operative

  2. [The hygienic characteristics of the medical technology accompaniment to the development, creation and operation of installations equipped with video display terminals].

    Prygun, A V; Lazarev, N V

    1998-10-01

    Radiation measuring on the work places of operators in command and control installations proved that environment parameters depending on electronic display functioning are in line with the regulations' requirements. Nevertheless the operator health estimates show that the problem of personnel security still exists. The authors recommend some measures to improve the situation.

  3. Research on the Error Characteristics of a 110 kV Optical Voltage Transformer under Three Conditions: In the Laboratory, Off-Line in the Field and During On-Line Operation

    Xiao, Xia; Hu, Haoliang; Xu, Yan; Lei, Min; Xiong, Qianzhu

    2016-01-01

    Optical voltage transformers (OVTs) have been applied in power systems. When performing accuracy performance tests of OVTs large differences exist between the electromagnetic environment and the temperature variation in the laboratory and on-site. Therefore, OVTs may display different error characteristics under different conditions. In this paper, OVT prototypes with typical structures were selected to be tested for the error characteristics with the same testing equipment and testing method. The basic accuracy, the additional error caused by temperature and the adjacent phase in the laboratory, the accuracy in the field off-line, and the real-time monitoring error during on-line operation were tested. The error characteristics under the three conditions—laboratory, in the field off-line and during on-site operation—were compared and analyzed. The results showed that the effect of the transportation process, electromagnetic environment and the adjacent phase on the accuracy of OVTs could be ignored for level 0.2, but the error characteristics of OVTs are dependent on the environmental temperature and are sensitive to the temperature gradient. The temperature characteristics during on-line operation were significantly superior to those observed in the laboratory. PMID:27537895

  4. Hanaro operation

    Lee, Ji Bok; Jeon, Byung Jin; Kwack, Byung Ho

    1997-01-01

    HANARO was configurated its first operating core in 1995. Long term operation test was conducted up to 3-1 cycle during 1996, in order to investigate the reactor characteristics due to fuel depletion and additional fuel loading. Now HANARO has accumulated 168.4 days of total operation time and 2,687.5 MWD of total thermal output. Reactor analysis, producing operation datum and its validation with test, periodic inspection and maintenance of the facility are continuously conducted for safe operation of the HANARO. Conducted the verification tests for installed utilization facilities, and successfully performed the radiation emergency drill. The shutdown report of TRIGA Mark II and III was submitted to MOST, and decommissioning will be started from 1997. (author). 70 tabs., 50 figs., 27 refs

  5. Receiver operating characteristic (ROC) curves and the definition of threshold levels to diagnose coronary artery disease on electrocardiographic stress testing. Part II: the use of ROC curves in the choice of electrocardiographic stress test markers of ischaemia.

    Marazìa, Stefania; Barnabei, Luca; De Caterina, Raffaele

    2008-01-01

    A common problem in diagnostic medicine, when performing a diagnostic test, is to obtain an accurate discrimination between 'normal' cases and cases with disease, owing to the overlapping distributions of these populations. In clinical practice, it is exceedingly rare that a chosen cut point will achieve perfect discrimination between normal cases and those with disease, and one has to select the best compromise between sensitivity and specificity by comparing the diagnostic performance of different tests or diagnostic criteria available. Receiver operating characteristic (or receiver operator characteristic, ROC) curves allow systematic and intuitively appealing descriptions of the diagnostic performance of a test and a comparison of the performance of different tests or diagnostic criteria. This review will analyse the basic principles underlying ROC curves and their specific application to the choice of optimal parameters on exercise electrocardiographic stress testing. Part II will be devoted to the comparative analysis of various parameters derived from exercise stress testing for the diagnosis of underlying coronary artery disease.

  6. Operating characteristics of depression and anxiety disorder phenotype dimensions and trait neuroticism: a theoretical examination of the fear and distress disorders from the Netherlands study of depression and anxiety.

    Tully, Phillip J; Wardenaar, Klaas J; Penninx, Brenda W J H

    2015-03-15

    The receiver operating characteristics (ROC) of anhedonic depression and anxious arousal to detect the distress- (major depression, dysthymia, generalized anxiety disorder) and fear-disorder clusters (i.e. panic disorder, agoraphobia, social phobia) have not been reported in a large sample. A sample of 2981 persons underwent structured psychiatric interview; n=652 were without lifetime depression and anxiety disorder history. Participants also completed a neuroticism scale (Revised NEO Five Factor Inventory [NEO-FFI]), and the 30-item short adaptation of the Mood and Anxiety Symptoms Questionnaire (MASQ-D30) measuring anhedonic depression, anxious arousal and general distress. Maximal sensitivity and specificity was determined by the Youden Index and the area-under-the-curve (AUC) in ROC analysis. A total of 2624 completed all measures (age M=42.4 years±13.1, 1760 females [67.1%]), including 1060 (40.4%) persons who met criteria for a distress-disorder, and 973 (37.1%) who met criteria for a fear-disorder. The general distress dimension provided the highest ROC values in the detection of the distress-disorders (AUC=.814, sensitivity=71.95%, specificity=76.34%, positive predictive value=67.33, negative predictive value=80.07). None of the measures provided suitable operating characteristics in the detection of the fear-disorders with specificity values depression and anxiety disorders may lead to inflated positive- and negative predictive values. The MASQ-D30 general distress dimension showed clinically suitable operating characteristics in the detection of distress-disorders. Neither neuroticism nor the MASQ-D30 dimensions provided suitable operating characteristics in the detection of the fear-disorders. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. The Effect of an Operating Propeller on the Aerodynamic Characteristics of a 1/10-Scale Model of the Lockheed XFV-1 Airplane at High Subsonic Speeds (TED No. NACA DE-377)

    Sutton, Fred B.; Buell, Donald A.

    1952-01-01

    An investigation was conducted in the Ames 12-foot pressure wind tunnel to determine the effect of an operating propeller on the aerodynamic characteristics of a l/l9-scale model of the Lockheed XFV-1 airplane, Several full-scale power conditions were simulated at Mach numbers from 0.50 to 0.92; the.Reynolds number was constant at 1,7 million. Lift, longitudinal force, pitch, roll, and yaw characteristics, determined with and without power, are presented for the complete model and for various combinations of model components, Results of an investigation to determine the characteristics of the dual-rotating propeller used on the model are given also,

  8. Oil transport scheduling in a pipeline with a characteristic operation; Otimizacao das operacoes de transporte de derivados em um poliduto com multiplas sangrias

    Kira, Guilherme; Magatao, Leandro; Arruda, Lucia Valeria Ramos; Silva, Marcos Henrique da [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Lara, Lucas El Ghoz [Petroleo Brasileiro S.A (PETROBRAS), Rio de Janeiro, RJ (Brazil); Ribas, Paulo Cesar [Petroleo Brasileiro S.A (CENPES/PETROBRAS), Rio de Janeiro, RJ (Brazil). Centro de Pesquisa e Desenvolvimento

    2012-07-01

    This work presents an optimization structure to support the operational decision making of scheduling activities in a multi product pipeline with multiple deliveries. This pipeline connects, in sequence, 6 operational areas: one is the main refinery, and the 5 remaining are distribution centers, each one with specific capacity of storage. Basically, the refinery pumps derivatives, such as diesel and gasoline, in a unidirectional flow to distribution centers, in a way to supply their demands. The solution kernel is underlined in a hybrid structure, using heuristics and Mixed Integer Linear Programming (MILP) modeling, executed iteratively. Details of storage curves and flow rate of pipelines are obtained in the proposed approach, expanding the results of Kira et al. (2010). Additionally, the proposed approach is able to deal with discrete demands along the scheduling horizon. Thus, this hybrid structure makes possible to obtain operational scheduling solutions at a low CPU times (few minutes), using real data scenarios, whose horizon length has at least 30 days. (author)

  9. Operational procedure for computer program for design point characteristics of a compressed-air generator with through-flow combustor for V/STOL applications

    Krebs, R. P.

    1971-01-01

    The computer program described in this report calculates the design-point characteristics of a compressed-air generator for use in V/STOL applications such as systems with a tip-turbine-driven lift fan. The program computes the dimensions and mass, as well as the thermodynamic performance of a model air generator configuration which involves a straight through-flow combustor. Physical and thermodynamic characteristics of the air generator components are also given. The program was written in FORTRAN IV language. Provision has been made so that the program will accept input values in either SI units or U.S. customary units. Each air generator design-point calculation requires about 1.5 seconds of 7094 computer time for execution.

  10. Assessment of the effect of Nd:YAG laser pulse operating parameters on the metallurgical characteristics of different tool steels using DOE software

    Muhič, T.; Kosec, L.; Liedl, G.; Pleterski, M.

    2011-01-01

    To ensure the reliability of repair welded tool surfaces, clad quality should be improved. The relationships between metallurgical characteristics of cladding and laser input welding parameters were studied using the design of experiments software. The influence of laser power, welding speed, focal point position and diameter of welding wire on the weld-bead geometry (i.e. penetration, cladding zone width and heat-affected-zone width), microstructural homogeneity, dilution and bond strength w...

  11. Code systems for effective and precise calculation of the basic neutron characteristics, core loading optimization, analysis and estimation of the operation regimes of WWER type reactors

    Apostolov, T.; Ivanov, K.; Prodanova, R.; Manolova, M.; Petrova, T.; Alekova, G.

    1993-01-01

    Two directions for investigations are suggested: 1) Analysis and evaluation of the real loading patterns and operational regimes for Kozloduy NPP WWER-440 and WWER-1000 in the frame of the recent safety criteria and nuclear power plant operating limits. 2) Development of modern code system for WWER type reactor core analysis with advanced features: new design and materials for fuel and control rods, increasing the fuel enrichment, using the integral and discrete burnable absorbers etc. The fuel technology design evolution maximizes the fuel utilization efficiency, improves operation performance and enhances safety margins. By the joint efforts of specialists from INRNE, Sofia (BG) and KAB, Berlin (GE), the codes NESSEL-IV-EC, PYTHIA and DERAB have been developed and verified. In the frame of the PHARE programme the joint project ASPERCA has been proposed intended for reactor physics calculations with PHYBER-WWER code for safety enhancement and operation reliability improvement. In-core fuel management benchmarks for 4 cycles of unit 2 (WWER-440) and 2 cycles of unit 5 (WWER-1000) have been performed. The coordination of burnable absorber design implementation, low leakage loadings usage, reloading enrichment increase and steel content reduction in the core have made the reactor core analysis more demanding and the definition of loading patterns - more difficult. This complexity requires routine use of three-dimensional fast accurate core model with extended and updated cross section libraries. To meet the needs of WWER advanced loading patterns and in-core fuel management improvements the HEXANES code systems is being developed and qualified. Some test calculations have been carried out by the HEXANES code system investigating the influence of Gd in the fuel on the main reactor physics parameters. For reevaluation of the core safety-related design limits forming the basis of licensing procedure, the code DYN3D/M2 is used. 16 refs., 3 figs. (author)

  12. Tumoral expression on Her-2, E R and P R and its Clinico pathological characteristics relation in Uruguayan and Argentine patients with operable breast cancer

    Delgado, L; Richardet, E; Pallotta, G; Fresco, R; Aguiar, S; Camejo, N; Gonzalez, V; Ferrero, L; Heinzen, S; Martinez, A. and others

    2010-01-01

    Introduction: the study of biological subtype of breast cancer (B C) given by the expression tumor estrogen receptors (E R), progesterone (P R) and growth factor receptor and evolutionary. Objective: To know the profile of tumor expression of HER2, ER and P R and their relation with to characteristics clinico pathological characteristics in Uruguayan and Argentine patients with breast cancer. Material and Methods: The medical records of patients who underwent analyzed C M I-III invasive stages between 03/2006 and 03/2008 and assisted in Oncology Services where the authors are performing, which had selected determination ER, P R and HER2 by immunohistochemistry. The expression profile of these was markers compared with age at diagnosis, type and histological grade (GH) and pathological stage (TNM). Results: 291 patients (197 Uruguayan and 94 Argentine) were included whose characteristics were: mean age: 56 years, ductal carcinoma: 85%, GH 1-2: 55% stage I-II: 70%, metastasis axillary: 51%, ER / P R +: 78% HER2 + 12%. Three subtypes were defined: HER2 ER / P R + (71%), HER2 + (12% Uruguayan patients: 10%, Argentine patients: 17%) and negative Triple (TN) (17%). The joint analysis of the patients in both countries showed that subtypes TN and HER2 is associated with greater histological grade (p <0.05). Furthermore, in the group of patients Uruguayan, TN subtype was associated with younger age at diagnosis (p <0.05) subtype HER2, ER / PR +. Conclusions: The percentage of patients with CM Uruguayan invasive HER2 + subtype (10%) is smaller than that reported by other studies (17-28%) and that observed in our study Argentine group of patients. Consistent with previous studies, TN subtypes and HER2 + correlated with more undifferentiated tumors and in the group of Uruguayan patients TN appeared in younger patients

  13. Assessment of the effect of Nd:YAG laser pulse operating parameters on the metallurgical characteristics of different tool steels using DOE software

    T. Muhič

    2011-04-01

    Full Text Available To ensure the reliability of repair welded tool surfaces, clad quality should be improved. The relationships between metallurgical characteristics of cladding and laser input welding parameters were studied using the design of experiments software. The influence of laser power, welding speed, focal point position and diameter of welding wire on the weld-bead geometry (i.e. penetration, cladding zone width and heat-affected-zone width, microstructural homogeneity, dilution and bond strength was investigated on commonly used tool steels 1,2083, 1,2312 and 1,2343, using DOE software.

  14. Test characteristics of high frequency ultrasound in the pre-operative assessment of margins of basal cell and squamous cell carcinoma in patients undergoing Mohs micrographic surgery

    Jambusaria-Pahlajani, Anokhi; Schmults, Chrysalyne D.; Miller, Christopher J.; Shin, Daniel; Williams, Jennifer; Kurd, Shanu K; Gelfand, Joel M.

    2015-01-01

    Background Non-invasive techniques to assess subclinical spread of non-melanoma skin cancer (NMSC) may improve surgical precision. High frequency ultrasound (HIFU) has shown promise to evaluate the extent of NMSC. Objective To determine the accuracy of HIFU to assess the margins of basal cell (BCC) and squamous cell carcinomas (SCC) prior to Mohs micrographic surgery (MMS). Methods We enrolled 100 patients with invasive SCC or BCC. Prior to the first stage of MMS, a Mohs surgeon delineated the intended surgical margin. Subsequently, a trained ultrasound technologist independently evaluated disease extent using the EPISCAN I-200 to evaluate tumor extent beyond this margin. The accuracy of HIFU was subsequently tested by comparison to pathology from frozen sections. Results The test characteristics of the ultrasound were sensitivity= 32%, specificity= 88%, positive predictive value= 47%, and negative predictive value=79%. Subgroup analyses demonstrated improved test characteristics for tumors larger than the median (area >1.74 cm2). Qualitative analyses showed that HIFU was less likely to identify extension from tumors with subtle areas of extension, such as small foci of dermal invasion from infiltrative SCC and micronodular BCC. Conclusions HIFU requires additional refinements to improve the preoperative determination of tumor extent prior to surgical treatment of NMSC. PMID:19018815

  15. Experimental study on the operating characteristics of an inner preheating transpiring wall reactor for supercritical water oxidation: Temperature profiles and product properties

    Zhang, Fengming; Xu, Chunyan; Zhang, Yong; Chen, Shouyan; Chen, Guifang; Ma, Chunyuan

    2014-01-01

    A new process to generate multiple thermal fluids by supercritical water oxidation (SCWO) was proposed to enhance oil recovery. An inner preheating transpiring wall reactor for SCWO was designed and tested to avoid plugging in the preheating section. Hot water (400–600 °C) was used as auxiliary heat source to preheat the feed to the reaction temperature. The effect of different operating parameters on the performance of the inner preheating transpiring wall reactor was investigated, and the optimized operating parameters were determined based on temperature profiles and product properties. The reaction temperature is close to 900 °C at an auxiliary heat source flow of 2.79 kg/h, and the auxiliary heat source flow is determined at 6–14 kg/h to avoid the overheating of the reactor. The useful reaction time is used to quantitatively describe the feed degradation efficiency. The outlet concentration of total organic carbon (TOC out ) and CO in the effluent gradually decreases with increasing useful reaction time. The useful reaction time needed for complete oxidation of the feed is 10.5 s for the reactor. - Highlights: • A new process to generate multiple thermal fluids by SCWO was proposed. • An inner preheating transpiring wall reactor for SCWO was designed and tested. • Hot water was used as auxiliary heat source to preheat the feed at room temperature. • Effect of operating parameters on the performance of the reactor was investigated. • The useful reaction time required for complete oxidation of the feed is 10.5 s

  16. The construction and operating characteristics of a cathode strip chamber system designed to measure the reaction vertices of a stopping kaon beam

    M.W. Ahmed; D. Androic; I. Bertovic; J. Bjoraker; R. Chrien; X. Cui; D. Dehnhard; Anton Empl; M. Furic; J. Gerald; R. Gill; E.V. Hungerford; H. Jungst; K.J. Lan; Jinghua Liu; C.L. Morris; J.M. O'Donnell; J.C. Peng; T. Petkovic; P. Pile; M. Planinic; C.M. Riedel; A. Rusek; R. Sutter; Liguang Tang; H.A. Thiessen; M. Youn; V. Zeps

    2001-01-01

    The design, construction, and performance of a segmented-target, cathode-strip, tracking-detector is discussed. The chamber was made of low-Z materials in order to allow photons to leave the target region. It was used to determine the reaction vertex of stopping kaons, and was successfully operated in a high-intensity kaon beamline at the Alternating Gradient Synchrotron at Brookhaven National Laboratory. The vertical and horizontal resolutions of the stopping kaon reaction positions were sigma X∼ 0.454mm and sigma Y∼ 1.180mm, respectively. The uncertainty in the longitudinal (Z) direction is given by one-half the thickness of a target segment

  17. Assessing rear-end crash potential in urban locations based on vehicle-by-vehicle interactions, geometric characteristics and operational conditions.

    Dimitriou, Loukas; Stylianou, Katerina; Abdel-Aty, Mohamed A

    2018-03-01

    Rear-end crashes are one of the most frequently occurring crash types, especially in urban networks. An understanding of the contributing factors and their significant association with rear-end crashes is of practical importance and will help in the development of effective countermeasures. The objective of this study is to assess rear-end crash potential at a microscopic level in an urban environment, by investigating vehicle-by-vehicle interactions. To do so, several traffic parameters at the individual vehicle level have been taken into consideration, for capturing car-following characteristics and vehicle interactions, and to investigate their effect on potential rear-end crashes. In this study rear-end crash potential was estimated based on stopping distance between two consecutive vehicles, and four rear-end crash potential cases were developed. The results indicated that 66.4% of the observations were estimated as rear-end crash potentials. It was also shown that rear-end crash potential was presented when traffic flow and speed standard deviation were higher. Also, locational characteristics such as lane of travel and location in the network were found to affect drivers' car following decisions and additionally, it was shown that speeds were lower and headways higher when Heavy Goods Vehicles lead. Finally, a model-based behavioral analysis based on Multinomial Logit regression was conducted to systematically identify the statistically significant variables in explaining rear-end risk potential. The modeling results highlighted the significance of the explanatory variables associated with rear-end crash potential, however it was shown that their effect varied among different model configurations. The outcome of the results can be of significant value for several purposes, such as real-time monitoring of risk potential, allocating enforcement units in urban networks and designing targeted proactive safety policies. Copyright © 2018 Elsevier Ltd. All rights

  18. Scoping out the literature on mobile needle and syringe programs-review of service delivery and client characteristics, operation, utilization, referrals, and impact.

    Strike, Carol; Miskovic, Miroslav

    2018-02-08

    Needle and syringe program (NSP) service delivery models encompass fixed sites, mobile services, vending machines, pharmacies, peer NSPs, street outreach, and inter-organizational agreements to add NSP services to other programs. For programs seeking to implement or improve mobile services, access to a synthesis of the evidence related to mobile services is beneficial, but lacking. We used a scoping study method to search MEDLINE, PSYCHInfo, Embase, Scopus, and Sociological for relevant literature. We identified 39 relevant manuscripts published between 1975 and November 2017 after removing duplicates and non-relevant manuscripts from the 1313 identified by the search. Charting of the data showed that these publications reported findings related to the service delivery model characteristics, client characteristics, service utilization, specialized interventions offered on mobile NSPs, linking clients to other services, and impact on injection risk behaviors. Mobile NSPs are implemented in high-, medium-, and low-income countries; provide equipment distribution and many other harm reduction services; face limitations to service complement, confidentiality, and duration of interactions imposed by physical space; adapt to changes in locations and types of drug use; attract people who engage in high-risk/intensity injection behavior and who are often not reached by other service models; and may lead to reduced injection-related risks. It is not clear from the literature reviewed, what are, or if there are, a "core and essential" complement of services that mobile NSPs should offer. Decisions about service complement for mobile NSPs need to be made in relation to the context and also other available services. Reports of client visits to mobile NSP provide a picture of the volume and frequency of utilization but are difficult to compare given varied measures and reference periods. Mobile NSPs have an important role to play in improving HIV and HCV prevention efforts

  19. [The organizational characteristics of the medical support for the troops in the first operations at the start of a war (based on the experience of exercises)].

    Iziumtsev, I S

    1995-03-01

    The article summarized the experience of an explorative tactical-special exercise on medical support of Mobile Forces in first military operations of the initial period of war which has studied the following questions: the organic structure and organization of work of the medical service of a motorized infantry brigade in defense; joint direction of organic hospital facilities and field traumatological hospital. The author also studies the deployment peculiarities of a military multipurpose hospital on the basis of a garrison hospital. The experience of these exercises has proved the necessity to update the organic structure and principles of the employment of medical assets in accordance with the requirements of new military doctrine, as well as realize the technical re-equipment of medical service.

  20. The construction and operating characteristics of a cathode strip chamber system designed to measure the reaction vertices of a stopping kaon beam

    Ahmed, M.W.; Androic, D.; Bertovic, I.; Bjoraker, J.; Chrien, R.; Cui, X.; Dehnhard, D.; Empl, A.; Furic, M.; Gerald, J.; Gill, R.; Hungerford, E.V.; Juengst, H.; Lan, K.J.; Liu, J.H.; Morris, C.L.; O'Donnell, J.M.; Peng, J.C.; Petkovic, T.; Pile, P.; Planinic, M.; Riedel, C.M.; Rusek, A.; Sutter, R.; Tang, L.; Thiessen, H.A.; Youn, M.; Zeps, V.

    2001-01-01

    The design, construction, and performance of a segmented-target, cathode-strip, tracking-detector is discussed. The chamber was made of low-Z materials in order to allow photons to leave the target region. It was used to determine the reaction vertex of stopping kaons, and was successfully operated in a high-intensity kaon beamline at the Alternating Gradient Synchrotron at Brookhaven National Laboratory. The vertical and horizontal resolutions of the stopping kaon reaction positions were σ X ∼0.454 mm and σ Y ∼1.180 mm, respectively. The uncertainty in the longitudinal (Z) direction is given by one-half the thickness of a target segment

  1. The construction and operating characteristics of a cathode strip chamber system designed to measure the reaction vertices of a stopping kaon beam

    Ahmed, M W; Bertovic, I; Bjoraker, J; Chrien, R; Cui, X; Dehnhard, D; Empl, A; Furic, M; Gerald, J; Gill, R; Hungerford, E V; Juengst, H; Lan, K J; Liu, J H; Morris, C L; O'donnell, J M; Peng, J C; Petkovic, T; Pile, P; Planinic, M; Riedel, C M; Rusek, A; Sutter, R; Tang, L; Thiessen, H A; Youn, M; Zeps, V

    2001-01-01

    The design, construction, and performance of a segmented-target, cathode-strip, tracking-detector is discussed. The chamber was made of low-Z materials in order to allow photons to leave the target region. It was used to determine the reaction vertex of stopping kaons, and was successfully operated in a high-intensity kaon beamline at the Alternating Gradient Synchrotron at Brookhaven National Laboratory. The vertical and horizontal resolutions of the stopping kaon reaction positions were sigma sub X approx 0.454 mm and sigma sub Y approx 1.180 mm, respectively. The uncertainty in the longitudinal (Z) direction is given by one-half the thickness of a target segment.

  2. Photoperiodism and Crassulacean acid metabolism : III. Different characteristics of the photoperiod-sensitive and non-sensitive isoforms of phosphoenolpyruvate carboxylase and Crassulacean acid metabolism operation.

    Brulfert, J; Queiroz, O

    1982-05-01

    Sensitivity to glucose-6-P, inorganic phosphate and malate, Km phosphoenolpyruvate (PEP), and the effect of pH were comparatively investigated for phosphoenolpyruvate carboxylase (PEPC, EC 4.1.1.31) extracted along the day-night cycle from leaves of Kalanchoe blossfeldiana v. Poelln. Tom Thumb, grown under different photoperiodic conditions. Under long days, sensitivity to effectors is weak and varies only slightly during the 24h cycle, together with small variations of Km (PEP), ranging from 1.2 to 1.8 mM. The response-curve to pH shows two peaks for pH 7.4 and 8.4. Transfer of the plants to short days established an increase in the sensitivity of the enzyme to the effectors together with the appearance of a day-night variation of this effect, maximum during the day. A clear diurnal oscillation of Km (PEP) is observed from 3.1 mM at the beginning of day (09.00 h) to 0.9 mM at midnight (00.00 h), at pH 7.4. These results complement previous electrophoretic and immunological data by affording enzyme kinetic evidence that short days induce a PEP carboxylase form responsible for full-Crassulacean acid metabolism (CAM) operation which is kinetically different from the photoperiod-sensitive, C3-like form prevailing in young leaves under long days. The results indicate that diurnal enzymic rhythms would improve the efficiency of the metabolic regulatory mechanisms and act as a coordinating factor for the daily and seasonal adaptive operation of CAM.

  3. Modulation of the operational characteristics of amorphous In-Ga-Zn-O thin-film transistors by In2O3 nanoparticles

    Lee, Min-Jung; Lee, Tae Il; Park, Jee Ho; Baik, Hong Koo; Myoung, Jae-Min; Kim, Jung Han; Chae, Gee Sung; Jun, Myung Chul; Hwang, Yong Kee; Lee, Woong

    2012-01-01

    The structure of thin-film transistors (TFTs) based on amorphous In-Ga-Zn-O (a-IGZO) was modified by spin coating a suspension of In 2 O 3 nanoparticles on a SiO 2 /p ++ Si layered wafer surface prior to the deposition of IGZO layer by room-temperature sputtering. The number of particles per unit area (surface density) of the In 2 O 3 nanoparticles could be controlled by applying multiple spin coatings of the nanoparticle suspension. During the deposition of IGZO, the In 2 O 3 nanoparticles initially located on the substrate surface migrated to the top of the IGZO layer indicating that they were not embedded within the IGZO layer, but they supplied In to the IGZO layer to increase the In concentration in the channel layer. As a result, the channel characteristics of the a-IGZO TFT were modulated so that the device showed an enhanced performance as compared with the reference device prepared without the nanoparticle treatment. Such an improved device performance is attributed to the nano-scale changes in the structure of (InO) n ordering assisted by increased In concentration in the amorphous channel layer. (paper)

  4. Management, operational, animal health, and economic characteristics of large dairy herds in 4 states in the Upper Midwest of the United States.

    Evink, T L; Endres, M I

    2017-11-01

    Recent trends in dairy farm structure in the United States have included a decreasing number of farms, although farm size has increased, especially the share of milk production from very large herds (>2,500 cows). The objectives of this observational study were to describe common management practices; to characterize labor and operational structure; to measure some aspects of animal health, including lameness, hock lesions, mortality, and mastitis incidence; and to summarize cost of production on farms with more than 2,500 cows in 4 states in the Upper Midwest of the United States. The study included 15 dairy farms in Minnesota, Wisconsin, Iowa, and South Dakota. Farms were visited twice, once each year, and on-farm herd records were collected for those 2 yr. On-farm herd records were used to investigate mortality, culling, pregnancy rate, and clinical mastitis incidence. At least 1 high-producing pen of mature cows and 1 pen of fresh cows were scored for locomotion. Likewise, at least 1 pen of high-producing mature cows was scored for cleanliness and hock lesions. Median herd size was 3,975 cows (range = 2,606-13,266). Milk sold per employee was 1,120,745 kg and the number of cows per employee was 105. Eighty percent of the farms had Holstein cows, 13% had Jersey, and 7% had Jersey-Holstein crosses. All farms used artificial insemination as the sole form of breeding and 100% of the farms used hormonal synchronization or timed artificial insemination programs in their reproductive protocols; 21-d pregnancy rate was 21.7%. Median lameness prevalence was 18.3% and median severe lameness prevalence was 5.1%. Median hock lesion prevalence was 17.4% and median severe hock lesion prevalence was 1.9%; mortality rate was 7.4%. Clinical mastitis incidence was 62.5 cases per 100 cow-years. Feed costs accounted for approximately 53% of the total cost of producing milk, followed by labor at 11%, interest and depreciation expenses at 10%, and replacement costs at 9.5%. Herds in

  5. Experimental and theoretical comparison of fuel temperature and bulk coolant characteristics in the Oregon State TRIGA reactor during steady state operation

    Marcum, W.R., E-mail: marcumw@engr.orst.ed [Oregon State University, Department of Nuclear Engineering and Radiation Health Physics, 116 Radiation Center, Corvallis, OR 97330 (United States); Woods, B.G.; Reese, S.R. [Oregon State University, Department of Nuclear Engineering and Radiation Health Physics, 116 Radiation Center, Corvallis, OR 97330 (United States)

    2010-01-15

    In September of 2008 Oregon State University (OSU) completed its core conversion analysis as part of the Reduced Enrichment for Research and Test Reactors (RERTR) Program. Experimental bulk coolant temperatures were collected in various locations throughout the Oregon State TRIGA Reactor (OSTR) core in order to supplement the validity of the numerical thermal hydraulic results produced in RELAP5-3D Version 2.4.2. Axial bulk coolant temperature distributions were collected by acquiring discrete thermocouple measurements in individual subchannel locations during steady state operation at 1.0 MW{sub th}. The experimental axial temperature distribution collected was compared to one-channel, two-channel, and eight-channel RELAP5-3D models and found to match within 11.94%, 11.69%, and 8.78%, respectively, on average. Comparisons to similar studies were made based on a dimensional analysis of fluid body forces in the discrete core locations, indicating that the chosen approach produces conservative results for use in the OSTR safety analysis.

  6. Epidemiological and immunological characteristics of childhood leukaemia in the Netherlands: population-based data from a nationwide co-operative group of paediatricians

    Coebergh, J.W.W.; Steensel-Moll, A. van; Veer, M.B. van't

    1985-01-01

    Results are reviewed from several population-based epidemiological and immunological studies of children with leukaemia in The Netherlands, who were diagnosed between 1973 and 1982 through a nationwide co-operative group of paediatricians. From 1973 till 1980 annual incidence rates appeared to be 3.1 per 10 5 person-yr. No significant trend was observed in this period. However a preliminary analysis of patients in the 1980-1982 period showed an increase. Mortality rates are decreasing since 1973, as expected. Incidence rates and proportions of different morphological and immunological subtypes reflect the pattern of occurrence in populations with a high standard of living. A relatively high incidence rate of acute lymphocytic leukaemia (ALL) is observed with a peak at the age of 3-5. The proportion of patients with T-cell phenotype among ALL-patients, immunologically typed between 1979 and 1982, appeared to increase with age, while the proportion of common ALL decreased. Statistical analysis of the data of patients with ALL in the Western part of the country including areas with nuclear plants, gave no indication for the presence of clustering. (author)

  7. Characteristics of fatal abusive head trauma among children in the USA: 2003-2007: an application of the CDC operational case definition to national vital statistics data.

    Parks, Sharyn E; Kegler, Scott R; Annest, Joseph L; Mercy, James A

    2012-06-01

    In March of 2008, an expert panel was convened at the Centers for Disease Control and Prevention to develop code-based case definitions for abusive head trauma (AHT) in children under 5 years of age based on the International Classification of Diseases, 10th Revision (ICD-10) nature and cause of injury codes. This study presents the operational case definition and applies it to US death data. National Center for Health Statistics National Vital Statistics System data on multiple cause-of-death from 2003 to 2007 were examined. Inspection of records with at least one ICD-10 injury/disease code and at least one ICD-10 cause code from the AHT case definition resulted in the identification of 780 fatal AHT cases, with 699 classified as definite/presumptive AHT and 81 classified as probable AHT. The fatal AHT rate was highest among children age definition can help to identify population subgroups at higher risk for AHT defined by year and month of death, age, sex and race/ethnicity. This type of definition may be useful for various epidemiological applications including research and surveillance. These activities can in turn inform further development of prevention activities, including educating parents about the dangers of shaking and strategies for managing infant crying.

  8. Simulation study on the operating characteristics of the heat pipe for combined evaporative cooling of computer room air-conditioning system

    Han, Zongwei; Zhang, Yanqing; Meng, Xin; Liu, Qiankun; Li, Weiliang; Han, Yu; Zhang, Yanhong

    2016-01-01

    In order to improve the energy efficiency of air conditioning systems in computer rooms, this paper proposed a new concept of integrating evaporative cooling air-conditioning system with heat pipes. Based on a computer room in Shenyang, China, a mathematical model was built to perform transient simulations of the new system. The annual dynamical performance of the new system was then compared with a typical conventional computer room air-conditioning system. The result showed that the new integrated air-conditioning system had better energy efficiency, i.e. 31.31% reduction in energy consumption and 29.49% increase in COP (coefficient of performance), due to the adoption of evaporative condenser and the separate type heat pipe technology. Further study also revealed that the incorporated heat pipes enabled a 36.88% of decrease in the operation duration of the vapor compressor, and a 53.86% of reduction for the activation times of the compressor, which could lead to a longer lifespan of the compressor. The new integrated evaporative cooling air-conditioning system was also tested in different climate regions. It showed that the energy saving of the new system was greatly affected by climate, and it had the best effect in cold and dry regions like Shenyang with up to 31.31% energy saving. In some warm and humid climate regions like Guangzhou, the energy saving could be achieved up to 13.66%. - Highlights: • A novel combined air-conditioning system of computer room is constructed. • The performance of the system and conventional system is simulated and compared. • The applicability of the system in different climate regions is investigated.

  9. Receiver operating characteristic (ROC) curves and the definition of threshold levels to diagnose coronary artery disease on electrocardiographic stress testing. Part I: The use of ROC curves in diagnostic medicine and electrocardiographic markers of ischaemia.

    Barnabei, Luca; Marazìa, Stefania; De Caterina, Raffaele

    2007-11-01

    A common problem in diagnostic medicine, when performing a diagnostic test, is to obtain an accurate discrimination between 'normal' cases and cases with disease, owing to the overlapping distributions of these populations. In clinical practice, it is exceedingly rare that a chosen cut point will achieve perfect discrimination between normal cases and those with disease, and one has to select the best compromise between sensitivity and specificity by comparing the diagnostic performance of different tests or diagnostic criteria available. Receiver operating characteristic (or receiver operator characteristic, ROC) curves allow systematic and intuitively appealing descriptions of the diagnostic performance of a test and a comparison of the performance of different tests or diagnostic criteria. This review will analyse the basic principles underlying ROC curves and their specific application to the choice of optimal parameters on exercise electrocardiographic (ECG) stress testing. Part I will focus on theoretical description and analysis along with reviewing the common problems related to the diagnosis of myocardial ischaemia by means of exercise ECG stress testing. Part II will be devoted to applying ROC curves to available diagnostic criteria through the analysis of ECG stress test parameters.

  10. TRIGA reactor characteristics

    Boeck, H.; Villa, M.

    2007-01-01

    This module describes the general design, characteristics and parameters of TRIGA reactors and fuels. It is recommended that most of this information should be incorporated into any reactor operator training program and, in many cases, the facility Safety Analysis Report. It is oriented to teach the basics of the physics and mechanical design of the TRIGA fuel as well as its unique operational characteristics and the differences between TRIGA fuels and others more traditional reactor fuels. (nevyjel)

  11. 大型风电机组限功率运行特性分析及其优化调度%Power-limited Operation Characteristic Analysis and Optimal Scheduling for Large Scale Wind Turbines

    肖运启; 贺贯举

    2014-01-01

    近年来大量风电场的并网给电网安全运行带来困难,为此电网调度部门对所辖风电场提出了严格的限发要求。变速风电机组需要从传统的最大风能利用运行模式向限功率运行模式转变,由于风力机功率特性具有强非线性,运行模式的改变对风电机组以及风电场的控制策略提出了更高的设计要求。提出了一种考虑风电机组限功率运行状态优化的风电场功率调度策略。首先,基于小扰动分析方法分析了限功率运行下风电机组非线性模型的稳定特性;然后,提出了一种限功率运行状态评价指标;接下来,建立了风电场功率调度多目标优化模型,并基于遗传算法设计了求解策略。最后,结合实际算例验证了所提调度策略的有效性。%In recent years,a large number of wind farms have been connected to grid which causes difficulty in maintaining secure grid operations,consequently,the dispatch centers often need to require the wind farms to limit their power output strictly.As a result,the operating mode of wind turbines and wind farm needs to be transferred from traditional maximum wind energy tracking to power limited operating conditions. However,given the strong nonlinear characteristics of the turbines,changing operating mode requires more complex control strategies for both the wind turbines and wind farms.A wind farm power optimum dispatching strategy,considering the wind turbine power limited operation conditions,is proposed.A small disturbance analysis method is adopted to analyze the stability for power limited operations.An assessment index is presented to evaluate the operating modes.A multi-objective optimization model is established using genetic algorithms. Numerical examples are given to validate the efficiency of the strategy proposed.

  12. Machine parameters and characteristic features

    Le Duff, J.

    1979-01-01

    The design and operating characteristics of LEP are presented. Its probable performance, possible improvements and cost are discussed and some comparisons are drawn with machines currently in operation. (W.D.L.)

  13. Computational Fluid Dynamics-Population Balance Model Simulation of Effects of Cell Design and Operating Parameters on Gas-Liquid Two-Phase Flows and Bubble Distribution Characteristics in Aluminum Electrolysis Cells

    Zhan, Shuiqing; Wang, Junfeng; Wang, Zhentao; Yang, Jianhong

    2018-02-01

    The effects of different cell design and operating parameters on the gas-liquid two-phase flows and bubble distribution characteristics under the anode bottom regions in aluminum electrolysis cells were analyzed using a three-dimensional computational fluid dynamics-population balance model. These parameters include inter-anode channel width, anode-cathode distance (ACD), anode width and length, current density, and electrolyte depth. The simulations results show that the inter-anode channel width has no significant effect on the gas volume fraction, electrolyte velocity, and bubble size. With increasing ACD, the above values decrease and more uniform bubbles can be obtained. Different effects of the anode width and length can be concluded in different cell regions. With increasing current density, the gas volume fraction and electrolyte velocity increase, but the bubble size keeps nearly the same. Increasing electrolyte depth decreased the gas volume fraction and bubble size in particular areas and the electrolyte velocity increased.

  14. Evidence-Based Cutoff Threshold Values from Receiver Operating Characteristic Curve Analysis for Knee Osteoarthritis in the 50-Year-Old Korean Population: Analysis of Big Data from the National Health Insurance Sharing Service

    Hyunseok Jee

    2018-01-01

    Full Text Available We aimed to investigate the characteristics of patients with osteoarthritis (OA, using the data of all Koreans registered in the National Health Insurance Sharing Service Database (NHISS DB, and to provide ideal alternative cutoff thresholds for alleviating OA symptoms. Patients with OA (codes M17 and M17.1–M17.9 in the Korean Standard Classification of Disease and Causes of Death were analyzed using SAS software. Optimal cutoff thresholds were determined using receiver operating characteristic curve analysis. The 50-year age group was the most OA pathogenic group (among 40~70 years, n=2088. All exercise types affected the change of body mass index (p<0.05 and the sex difference in blood pressure (BP (p<0.01. All types of exercise positively affected the loss of waist circumference and the balance test (standing time on one leg in seconds (p<0.01. The cutoff threshold for the time in seconds from standing up from a chair to walking 3 m and returning to the same chair was 8.25 (80% sensitivity and 100% specificity. By using the exercise modalities, categorized multiple variables, and the cutoff threshold, an optimal alternative exercise program can be designed for alleviating OA symptoms in the 50-year age group.

  15. Characteristics of a Steadily Operating Metal Combustor

    1976-08-01

    Physique, Serie 7, Vol. 17, p. 510-576, 1899. 18. Zintl, E., Harder, A., and Dauth, B., "Gitterstruktur Der Oxyde , Sulfide, Selenide Und Telluride Des...ethyl alcohol were added to the cylinder along with three drops of alizarin Red S indicator (1%). The solution was titrated with thorium nitrate until...the appearance of a faint pink color. The thorium nitrate precipitated thorium fluoride which is insoluble in ethyl alcohol , and the indicator detected

  16. Sensitivity analysis for publication bias in meta-analysis of diagnostic studies for a continuous biomarker.

    Hattori, Satoshi; Zhou, Xiao-Hua

    2018-02-10

    Publication bias is one of the most important issues in meta-analysis. For standard meta-analyses to examine intervention effects, the funnel plot and the trim-and-fill method are simple and widely used techniques for assessing and adjusting for the influence of publication bias, respectively. However, their use may be subjective and can then produce misleading insights. To make a more objective inference for publication bias, various sensitivity analysis methods have been proposed, including the Copas selection model. For meta-analysis of diagnostic studies evaluating a continuous biomarker, the summary receiver operating characteristic (sROC) curve is a very useful method in the presence of heterogeneous cutoff values. To our best knowledge, no methods are available for evaluation of influence of publication bias on estimation of the sROC curve. In this paper, we introduce a Copas-type selection model for meta-analysis of diagnostic studies and propose a sensitivity analysis method for publication bias. Our method enables us to assess the influence of publication bias on the estimation of the sROC curve and then judge whether the result of the meta-analysis is sufficiently confident or should be interpreted with much caution. We illustrate our proposed method with real data. Copyright © 2017 John Wiley & Sons, Ltd.

  17. Urinary neutrophil gelatinase-associated lipocalin for diagnosis and estimating activity in lupus nephritis: a meta-analysis.

    Fang, Y G; Chen, N N; Cheng, Y B; Sun, S J; Li, H X; Sun, F; Xiang, Y

    2015-12-01

    Urinary neutrophil gelatinase-associated lipocalin (uNGAL) is relatively specific in lupus nephritis (LN) patients. However, its diagnostic value has not been evaluated. The aim of this review was to determine the value of uNGAL for diagnosis and estimating activity in LN. A comprehensive search was performed on PubMed, EMBASE, Web of Knowledge, Cochrane electronic databases through December 2014. Meta-analysis of sensitivity and specificity was performed with a random-effects model. Additionally, summary receiver operating characteristic (SROC) curves and area under the curve (AUC) values were calculated. Fourteen studies were selected for this review. With respect to diagnosing LN, the pooled sensitivity and specificity were 73.6% (95% confidence interval (CI), 61.9-83.3) and 78.1% (95% CI, 69.0-85.6), respectively. The SROC-AUC value was 0.8632. Regarding estimating LN activity, the pooled sensitivity and specificity were 66.2% (95% CI, 60.4-71.7) and 62.1% (95% CI, 57.9-66.3), respectively. The SROC-AUC value was 0.7583. In predicting renal flares, the pooled sensitivity and specificity were 77.5% (95% CI, 68.1-85.1) and 65.3% (95% CI, 60.0-70.3), respectively. The SROC-AUC value was 0.7756. In conclusion, this meta-analysis indicates that uNGAL has relatively fair sensitivity and specificity in diagnosing LN, estimating LN activity and predicting renal flares, suggesting that uNGAL is a potential biomarker in diagnosing LN and monitoring LN activity. © The Author(s) 2015.

  18. A new cement slurry modified with chitosan/alginate interpenetrating networks and hydroxyapatite: structural characteristics after long-term contact with hyper-saline produced water from oil well operations

    Santos, Ivory Marcos Gomes dos; Santos, Danilo Oliveira; Cestari, Antonio Reinaldo, E-mail: ivorymarcos@hotmail.com, E-mail: danilo.quimico@yahoo.com.br, E-mail: rcestari@gmail.com [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil). Departamento de Ciencia dos Materiais; Ribeiro, Joenesson Filip Santos, E-mail: joenesson.joe@hotmail.com [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil). Lab, Materiais e Calorimetria; Alves, Jose do Patrocinio Hora; Ferreira, Angelica Baganha, E-mail: jphalves@uol.com.br, E-mail: angelica.bferreira@itps.se.gov.br [Instituto Tecnologico e de Pesquisas do Estado de Sergipe (ITPS), Aracaju, SE (Brazil)

    2017-01-15

    Oil is an important source of energy, mainly in developing countries. Important research has been conducted to find cementing procedures that guarantee safe and cost-effective oil exploration below pre-salt layers. This work aimed to make a new cement paste with cement, seawater, silica, biopolymers (chitosan and sodium alginate) and hydroxyapatite (HA), found in nature. For comparison purposes, slurry without additives was prepared and characterized. The HA used was extracted from fish scales (Cynoscion acoupa) in optimized condition NaOH concentration, temperature and reaction time. Both slurry were prepared with ratios water/cement (w/c) and silica/cement (s/c) equal to 0.50 and 0.35, respectively. The new cement slurry was obtained with proportions of 5% of each biopolymer and HA with respect to the total weight of the cement. In the immersion tests, specimens were immersed in samples of hyper production of saline water by 35°C for 15 days. Thereafter, they were washed, dried and its surface layers were scraped. Before, the resulting materials were characterized. The values of the ratios Ca/Si of new cement slurry (3.38 ± 0.06) were superior compared to standard (2.58 ± 0.05). The new slurry had high thermal stability and low amounts of small crystallite-type portlandite (35.70 nm). Conversely, a slurry standard formed larger crystals of about 50.3 nm. Significantly, after continuous long-term contact of both slurries with hyper-saline produced water from oil well fields operations, in comparison with standard slurry structural characteristics, the new slurry has practically maintained its pristine chemical structure, as well as has shown crystallite-type particles of NaCl and Friedel’s/Kuzel’s salts with lower proportion. The presence of the biopolymers and HA has driven the improved the self-healing properties observed in the new cement slurry. In this first study, the new slurry has shown adequate characteristics to contribute to cost effective and

  19. A new cement slurry modified with chitosan/alginate interpenetrating networks and hydroxyapatite: structural characteristics after long-term contact with hyper-saline produced water from oil well operations

    Santos, Ivory Marcos Gomes dos; Santos, Danilo Oliveira; Cestari, Antonio Reinaldo

    2017-01-01

    Oil is an important source of energy, mainly in developing countries. Important research has been conducted to find cementing procedures that guarantee safe and cost-effective oil exploration below pre-salt layers. This work aimed to make a new cement paste with cement, seawater, silica, biopolymers (chitosan and sodium alginate) and hydroxyapatite (HA), found in nature. For comparison purposes, slurry without additives was prepared and characterized. The HA used was extracted from fish scales (Cynoscion acoupa) in optimized condition NaOH concentration, temperature and reaction time. Both slurry were prepared with ratios water/cement (w/c) and silica/cement (s/c) equal to 0.50 and 0.35, respectively. The new cement slurry was obtained with proportions of 5% of each biopolymer and HA with respect to the total weight of the cement. In the immersion tests, specimens were immersed in samples of hyper production of saline water by 35°C for 15 days. Thereafter, they were washed, dried and its surface layers were scraped. Before, the resulting materials were characterized. The values of the ratios Ca/Si of new cement slurry (3.38 ± 0.06) were superior compared to standard (2.58 ± 0.05). The new slurry had high thermal stability and low amounts of small crystallite-type portlandite (35.70 nm). Conversely, a slurry standard formed larger crystals of about 50.3 nm. Significantly, after continuous long-term contact of both slurries with hyper-saline produced water from oil well fields operations, in comparison with standard slurry structural characteristics, the new slurry has practically maintained its pristine chemical structure, as well as has shown crystallite-type particles of NaCl and Friedel’s/Kuzel’s salts with lower proportion. The presence of the biopolymers and HA has driven the improved the self-healing properties observed in the new cement slurry. In this first study, the new slurry has shown adequate characteristics to contribute to cost effective and

  20. Operating characteristics of a partial-block randomized crossover bioequivalence study for dutasteride, a drug with a long half-life: investigation through simulation and comparison with final results.

    Cai, Gengqian; Thiessen, Jake J; Baidoo, Charlotte A; Fossler, Michael J

    2010-10-01

    Studies to establish bioequivalence (BE) of a drug are important elements in support of drug applications. A typical BE study is conducted as a single dose, randomized, 2-period crossover design. For drugs with long half lives (≥ 48 hours) and evaluation of multiple BE objectives in 1 trial, this design may not be adequate. A parallel design may then be a more appropriate choice. However, parallel designs require increased sample size, which can become substantial. One option that is a compromise between the complete randomized block design and the parallel design is a partial-block crossover design. This approach came about during the development of a combination of dutasteride and tamsulosin. Previous experience with performing single-dose dutasteride studies suggested that 28 days of washout is needed between treatments because of its half-life of 7-9 days. Simulations were performed to assess the operating characteristics of this design using a previously developed PK model. Four scenarios were developed, and each scenario was simulated 500 times. The results showed that this design demonstrated acceptable consumer and producer risk. Partial-block crossover designs should be considered for studies when the half-life of the drug is long and there are more than 2 periods.

  1. Early construction and operation of the highly contaminated water treatment system in Fukushima Daiichi Nuclear Power Station (2). Dynamic characteristics of KURION media for Cs removal in simulated contaminated water

    Hijikata, Takatoshi; Uozumi, Koichi; Tsukada, Takeshi; Koyama, Tadafumi; Ishikawa, Keiji; Ono, Shoichi; Suzuki, Shunichi; Denton, Mark; Raymont, John

    2014-01-01

    The kinetic characteristics of the column were necessary property to be understood before actual operation. Hence, a functional small-scale zeolite column system was installed for conducting the experiments to understand decontamination behaviors. Each column has a 2 cm inner diameter and a 12 cm height, and 12 g of zeolite-type media was packed into the column. The column experiments were carried out with Kurion-zeolite, herschelite, at different feed rates of simulated water with different concentrations of Cs and sea salt. As expected from equilibrium ion-exchange isotherms obtained for KURION-herschelite, the adsorption of Cs is hampered by the existence of sea salt ratio. The difference in breakthrough behaviors can be ascribed to the difference in sea salt ratio. Above 1000 bed volumes, the adsorption rate of Cs was the same at a solution velocity of between 14 and 81 cm/min. Under the condition of a 3.4 wt% sea salt ratio, the performance of the media supplied by KURION was in the order surfactant modified zeolite < silver-impregnated engineered herschelite = herschelite (H). This result was suggested to evaluate the performance of KURION media on the actual columns. (author)

  2. Impact of FIB-4 index on hepatocellular carcinoma incidence during nucleos(t)ide analogue therapy in patients with chronic hepatitis B: An analysis using time-dependent receiver operating characteristic.

    Tada, Toshifumi; Kumada, Takashi; Toyoda, Hidenori; Tsuji, Kunihiko; Hiraoka, Atsushi; Tanaka, Junko

    2017-02-01

    Nucleos(t)ide analogue (NA) therapy has been reported to reduce the risk of hepatocellular carcinoma (HCC) development in patients with chronic hepatitis B (CHB). However, even during NA therapy, development of HCC has been observed in patients with CHB. Therefore, we clarified the predictive power of clinical factors for HCC incidence using receiver operating characteristic (ROC) analysis that takes time dependence into account. A total of 539 patients with CHB treated with NAs were enrolled. Univariate, multivariate, and time-dependent ROC curves for clinical factors associated with the development of HCC were analyzed. Eighty-one patients developed HCC during the follow-up period (median duration, 5.9 years). α-fetoprotein (AFP) and FIB-4 index at 24 weeks from the initiation of treatment and sex were significantly associated with HCC incidence according to the log-rank test. Cox proportional hazards models including the covariates of sex, hepatitis B genotype, basal core promoter mutations, AFP at 24 weeks, and FIB-4 index at 24 weeks showed that FIB-4 index >2.65 (HR, 5.03; 95% CI, 3.06-8.26; P patients with CHB receiving NA therapy is a risk factor for developing HCC. The FIB-4 index is an excellent predictor of HCC development. © 2016 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

  3. Differentiation between microcystin contaminated and uncontaminated fish by determination of unconjugated MCs using an ELISA anti-Adda test based on receiver-operating characteristic curves threshold values: application to Tinca tinca from natural ponds.

    Moreno, Isabel María; Herrador, M Ángeles; Atencio, Loyda; Puerto, María; González, A Gustavo; Cameán, Ana María

    2011-02-01

    The aim of this study was to evaluate whether the enzyme-linked immunosorbent assay (ELISA) anti-Adda technique could be used to monitor free microcystins (MCs) in biological samples from fish naturally exposed to toxic cyanobacteria by using receiver operating characteristic (ROC) curve software to establish an optimal cut-off value for MCs. The cut-off value determined by ROC curve analysis in tench (Tinca tinca) exposed to MCs under laboratory conditions by ROC curve analysis was 5.90-μg MCs/kg tissue dry weight (d.w.) with a sensitivity of 93.3%. This value was applied in fish samples from natural ponds (Extremadura, Spain) in order to asses its potential MCs bioaccumulation by classifying samples as either true positive (TP), false positive (FP), true negative (TN), or false negative (FN). In this work, it has been demonstrated that toxic cyanobacteria, mainly Microcystis aeruginosa, Aphanizomenon issatchenkoi, and Anabaena spiroides, were present in two of these ponds, Barruecos de Abajo (BDown) and Barruecos de Arriba (BUp). The MCs levels were detected in waters from both ponds with an anti-MC-LR ELISA immunoassay and were of similar values (between 3.8-6.5-μg MC-LR equivalent/L in BDown pond and 4.8-6.0-μg MC-LR equivalent/L in BUp). The MCs cut-off values were applied in livers from fish collected from these two ponds using the ELISA anti-Adda technique. A total of 83% of samples from BDown pond and only 42% from BUp were TP with values of free MCs higher than 8.8-μg MCs/kg tissue (d.w.). Copyright © 2009 Wiley Periodicals, Inc.

  4. Oscillators and operational amplifiers

    Lindberg, Erik

    2005-01-01

    A generalized approach to the design of oscillators using operational amplifiers as active elements is presented. A piecewise-linear model of the amplifier is used so that it make sense to investigate the eigenvalues of the Jacobian of the differential equations. The characteristic equation of the general circuit is derived. The dynamic nonlinear transfer characteristic of the amplifier is investigated. Examples of negative resistance oscillators are discussed.

  5. Spatial Operations

    Anda VELICANU

    2010-09-01

    Full Text Available This paper contains a brief description of the most important operations that can be performed on spatial data such as spatial queries, create, update, insert, delete operations, conversions, operations on the map or analysis on grid cells. Each operation has a graphical example and some of them have code examples in Oracle and PostgreSQL.

  6. Operational amplifiers

    Dostal, Jiri

    1993-01-01

    This book provides the reader with the practical knowledge necessary to select and use operational amplifier devices. It presents an extensive treatment of applications and a practically oriented, unified theory of operational circuits.Provides the reader with practical knowledge necessary to select and use operational amplifier devices. Presents an extensive treatment of applications and a practically oriented, unified theory of operational circuits

  7. Operation of the accelerator

    GANIL Team

    1992-01-01

    The operation of the GANIL accelerator during 1991 and the first half of 1992 is reported. Results obtained with new beams, metallic beams and the first tests with the new injector system using an ECR source installed on a 100 kV platform are also given. Statistics of operation and beam characteristics are presented. The computer control system is also discussed. (K.A.) 7 refs.; 3 figs.; 8 tabs

  8. ENERGY CHARACTERISTICS OF ETHANOL CHARACTERISTICS ...

    eobe

    CHARACTERISTICS OF ETHANOL-DIESEL MIX FOR AUTOMOTIVE. DIESEL ... diesel engine and the engine speed, torque, power and specific fuel consumption (sfc) were determine .... heated on an electric stove and stirred continuously.

  9. 14 CFR 29.239 - Spray characteristics.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Spray characteristics. 29.239 Section 29... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight Ground and Water Handling Characteristics § 29.239 Spray characteristics. If certification for water operation is requested, no spray characteristics...

  10. 14 CFR 27.239 - Spray characteristics.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Spray characteristics. 27.239 Section 27... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Flight Ground and Water Handling Characteristics § 27.239 Spray characteristics. If certification for water operation is requested, no spray characteristics...

  11. The characteristics of a pneumatic muscle

    Pietrala Dawid

    2017-01-01

    Full Text Available The article presents static and dynamic characteristics of pneumatic muscles. It presents the structure of the laboratory stand used to test pneumatic muscles. It discusses the methodology for determination of static and dynamic characteristics. The paper also illustrates characteristics showing the relationship of pneumatic muscles length and operating pressure, at a constant loading force (isotonic characteristics. It presents characteristics showing the relationship of pneumatic muscles shortening and values of loading forces, at a constant operational pressure (isobaric characteristics. It also shows the dependence of force generated by the muscle on the operating pressure, at a constant value of pneumatic muscles shortening (isometric characteristics. The paper also presents dynamic characteristics of a pneumatic muscle showing the response of an object to a gradual change in the operating pressure, at a constant loading force acting on the pneumatic muscle.

  12. The characteristics of a pneumatic muscle

    Pietrala, Dawid

    The article presents static and dynamic characteristics of pneumatic muscles. It presents the structure of the laboratory stand used to test pneumatic muscles. It discusses the methodology for determination of static and dynamic characteristics. The paper also illustrates characteristics showing the relationship of pneumatic muscles length and operating pressure, at a constant loading force (isotonic characteristics). It presents characteristics showing the relationship of pneumatic muscles shortening and values of loading forces, at a constant operational pressure (isobaric characteristics). It also shows the dependence of force generated by the muscle on the operating pressure, at a constant value of pneumatic muscles shortening (isometric characteristics). The paper also presents dynamic characteristics of a pneumatic muscle showing the response of an object to a gradual change in the operating pressure, at a constant loading force acting on the pneumatic muscle.

  13. Diagnostic value of WIF1 methylation for colorectal cancer: a meta-analysis

    Hu, Haochang; Li, Bin; Zhou, Cong; Ying, Xiuru; Chen, Min; Huang, Tianyi; Chen, Yuehong; Ji, Huihui; Pan, Ranran; Wang, Tiangong; Jiang, Danjie; Chen, Yanfei; Yang, Yong; Duan, Shiwei

    2018-01-01

    As a common antagonist of Wnt/β-catenin signaling, Wnt inhibitory factor 1 (WIF1) plays an important role in the tumor progression. The aim of our meta-analysis was to summarize the diagnostic value of WIF1 methylation in colorectal cancer (CRC). Eligible studies were retrieved by a systemic search among PubMed, Embase, CNKI, and Wanfang literature databases. The diagnostic value of WIF1 methylation for CRC was assessed by the summary receiver operating characteristics (SROC) test. Our meta-a...

  14. Operating systems

    Tsichritzis, Dionysios C; Rheinboldt, Werner

    1974-01-01

    Operating Systems deals with the fundamental concepts and principles that govern the behavior of operating systems. Many issues regarding the structure of operating systems, including the problems of managing processes, processors, and memory, are examined. Various aspects of operating systems are also discussed, from input-output and files to security, protection, reliability, design methods, performance evaluation, and implementation methods.Comprised of 10 chapters, this volume begins with an overview of what constitutes an operating system, followed by a discussion on the definition and pr

  15. Operational calculus

    Boehme, Thomas K

    1987-01-01

    Operational Calculus, Volume II is a methodical presentation of operational calculus. An outline of the general theory of linear differential equations with constant coefficients is presented. Integral operational calculus and advanced topics in operational calculus, including locally integrable functions and convergence in the space of operators, are also discussed. Formulas and tables are included.Comprised of four sections, this volume begins with a discussion on the general theory of linear differential equations with constant coefficients, focusing on such topics as homogeneous and non-ho

  16. Rectangular drift tube characteristics

    Denisov, D.S.; Musienko, Yu.V.

    1985-01-01

    Results on the study of the characteristics of a 50 x 100 mm aluminium drift tube are presented. The tube was filled with argon-methane and argon-isobutane mixtures. With 16 per cent methane concentration the largest deviation from a linear relation between the drift time and the drift path over 50 mm is less than 2 mm. The tube filled with argon-isobutane mixture is capable of operating in a limited streamer mode

  17. Temperature, salinity, and optical characteristics data from NOAA Office of Ocean Exploration Operation Deep Scope cruise in the Gulf of Mexico, August 7-17, 2004 (NODC Accession 0001965)

    National Oceanic and Atmospheric Administration, Department of Commerce — This accession includes physical, chemical, optical and ocean color measurements, video and still photography data collected during the Operation Deep Scope cruise,...

  18. Spacecraft operations

    Sellmaier, Florian; Schmidhuber, Michael

    2015-01-01

    The book describes the basic concepts of spaceflight operations, for both, human and unmanned missions. The basic subsystems of a space vehicle are explained in dedicated chapters, the relationship of spacecraft design and the very unique space environment are laid out. Flight dynamics are taught as well as ground segment requirements. Mission operations are divided into preparation including management aspects, execution and planning. Deep space missions and space robotic operations are included as special cases. The book is based on a course held at the German Space Operation Center (GSOC).

  19. The characteristics of a pneumatic muscle

    Pietrala Dawid

    2017-01-01

    The article presents static and dynamic characteristics of pneumatic muscles. It presents the structure of the laboratory stand used to test pneumatic muscles. It discusses the methodology for determination of static and dynamic characteristics. The paper also illustrates characteristics showing the relationship of pneumatic muscles length and operating pressure, at a constant loading force (isotonic characteristics). It presents characteristics showing the relationship of pneumatic muscles s...

  20. Operator substitution

    Hautus, M.L.J.

    1994-01-01

    Substitution of an operator into an operator-valued map is defined and studied. A Bezout-type remainder theorem is used to derive a number of results. The tensor map is used to formulate solvability conditions for linear matrix equations. Some applications to system theory are given, in particular

  1. Accelerator operations

    Anon.

    1979-01-01

    Operations of the SuperHILAC, the Bevatron/Bevalac, and the 184-inch Synchrocyclotron during the period from October 1977 to September 1978 are discussed. These include ion source development, accelerator facilities, the Heavy Ion Spectrometer System, and Bevelac biomedical operations

  2. Methodology for determination of the operational limits in a atmospheric oven as a function of the load characteristics; Metodologia para determinacao dos limites operacionais de um forno atmosferico em funcao das caracteristicas da carga

    Mundstock, Rene [Refinaria Alberto Pasqualini (REFAP), Canoas, RS (Brazil); Correa, Eduardo Coelho [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2000-07-01

    The necessity of increasing the crude processing with operation periods even greater, are resulting in Atmospheric Distillation Units in severe conditions, requiring even more rigorous operational procedures. The crude fired heaters are the critical equipment in this context, because they are the most susceptible to failures, if some determined limits are exceeded. This work was originated from the tube failure analysis of the fired heater F-101 of Alberto Pasqualini Refinery (REFAP), occurred in july/98, due to internal cocking, with unit emergency shut-down. During this analysis, it was verified that the operational limit of a fired heater cannot be determined only by its design thermal duty, it must be also taken into account the influence of the crude composition. This will determine, due to its film coefficient, the region of the radiation zone of the fired heater where it will begin the crude vaporization and will occur the greater temperatures. The work conclusions resulted on the revision of the Unit operational procedures and definition of new crude processing limits. The fired heater operates with no problems since then. (author)

  3. Guide for training nuclear power plant operators

    Cox, J.A.; Cagle, C.D.; Corbett, B.L.; Culbert, W.H.; Hamrick, T.P.; Hurt, S.S.; McCord, R.V.; Poteet, K.H.; Bates, A.E.G.; Casto, W.R.

    1977-01-01

    Topics covered include basic preparation, radiation safety and control, principles of reactor operation, general operating characteristics, facility design, safety systems, instrumentation, reactor theory, fuel handling and core parameters, radioactive material handling, and administrative procedures

  4. Reactor operation

    Shaw, J

    2013-01-01

    Reactor Operation covers the theoretical aspects and design information of nuclear reactors. This book is composed of nine chapters that also consider their control, calibration, and experimentation.The opening chapters present the general problems of reactor operation and the principles of reactor control and operation. The succeeding chapters deal with the instrumentation, start-up, pre-commissioning, and physical experiments of nuclear reactors. The remaining chapters are devoted to the control rod calibrations and temperature coefficient measurements in the reactor. These chapters also exp

  5. Operator programs and operator processes

    Bergstra, J.A.; Walters, P.

    2003-01-01

    We define a notion of program which is not a computer program but an operator program: a detailed description of actions performed and decisions taken by a human operator (computer user) performing a task to achieve a goal in a simple setting consisting of that user, one or more computers and a

  6. Operator theory

    2015-01-01

    A one-sentence definition of operator theory could be: The study of (linear) continuous operations between topological vector spaces, these being in general (but not exclusively) Fréchet, Banach, or Hilbert spaces (or their duals). Operator theory is thus a very wide field, with numerous facets, both applied and theoretical. There are deep connections with complex analysis, functional analysis, mathematical physics, and electrical engineering, to name a few. Fascinating new applications and directions regularly appear, such as operator spaces, free probability, and applications to Clifford analysis. In our choice of the sections, we tried to reflect this diversity. This is a dynamic ongoing project, and more sections are planned, to complete the picture. We hope you enjoy the reading, and profit from this endeavor.

  7. Operation Starvation

    Mason, Gerald

    2002-01-01

    More than 1,250,000 tons of shipping was sunk or damaged in the last five months of World War II when Twenty-first Bomber Command executed an aerial mining campaign against Japan known as Operation STARVATION...

  8. Peace Operations

    Proks, Josef

    2000-01-01

    Peace operations are more and more important in the contemporary world. The end of the Cold War increased not only possibilities of solving disputes by the international community but also by the number and diversity of threats and issues...

  9. Operator training

    Wirstad, J.

    1983-12-01

    The traditional operator job is changing, which among other things has generated a need for better job training. Surprisingly increased process automation has lead to increased operator qualifications, i.e. basic job training but also up-date and rehearsal training within certain fixed intervals. There are several, similar models for instructional system development available in the literature. One model which is of special interest integrates Operator Training development and Man-Machine Interfaces development. The extent to which Systematic Operator Training has been implemented varies with branches and companies. The nuclear power branch is given as an example in the report. This branch probably represents something better than the average among the process industries.(author)

  10. Operative Links

    Wistoft, Karen; Højlund, Holger

    2012-01-01

    educational goals, learning content, or value clarification. Health pedagogy is often a matter of retrospective rationalization rather than the starting point of planning. Health and risk behaviour approaches override health educational approaches. Conclusions: Operational links between health education......, health professionalism, and management strategies pose the foremost challenge. Operational links indicates cooperative levels that facilitate a creative and innovative effort across traditional professional boundaries. It is proposed that such links are supported by network structures, shared semantics...

  11. Pump characteristics and applications

    Volk, Michael

    2013-01-01

    Providing a wealth of information on pumps and pump systems, Pump Characteristics and Applications, Third Edition details how pump equipment is selected, sized, operated, maintained, and repaired. The book identifies the key components of pumps and pump accessories, introduces the basics of pump and system hydraulics as well as more advanced hydraulic topics, and details various pump types, as well as special materials on seals, motors, variable frequency drives, and other pump-related subjects. It uses example problems throughout the text, reinforcing the practical application of the formulae

  12. ITER safety and operational scenario

    Shimomura, Y.; Saji, G.

    1998-01-01

    The safety and environmental characteristics of ITER and its operational scenario are described. Fusion has built-in safety characteristics without depending on layers of safety protection systems. Safety considerations are integrated in the design by making use of the intrinsic safety characteristics of fusion adequate to the moderate hazard inventories. In addition to this, a systematic nuclear safety approach has been applied to the design of ITER. The safety assessment of the design shows how ITER will safely accommodate uncertainties, flexibility of plasma operations, and experimental components, which is fundamental in ITER, the first experimental fusion reactor. The operation of ITER will progress step by step from hydrogen plasma operation with low plasma current, low magnetic field, short pulse and low duty factor without fusion power to deuterium-tritium plasma operation with full plasma current, full magnetic field, long pulse and high duty factor with full fusion power. In each step, characteristics of plasma and optimization of plasma operation will be studied which will significantly reduce uncertainties and frequency/severity of plasma transient events in the next step. This approach enhances reliability of ITER operation. (orig.)

  13. Applied Operations Research: Operator's Assistant

    Cole, Stuart K.

    2015-01-01

    NASA operates high value critical equipment (HVCE) that requires trouble shooting, periodic maintenance and continued monitoring by Operations staff. The complexity HVCE and information required to maintain and trouble shoot HVCE to assure continued mission success as paper is voluminous. Training on new HVCE is commensurate with the need for equipment maintenance. LaRC Research Directorate has undertaken a proactive research to support Operations staff by initiation of the development and prototyping an electronic computer based portable maintenance aid (Operator's Assistant). This research established a goal with multiple objectives and a working prototype was developed. The research identified affordable solutions; constraints; demonstrated use of commercial off the shelf software; use of the US Coast Guard maintenance solution; NASA Procedure Representation Language; and the identification of computer system strategies; where these demonstrations and capabilities support the Operator, and maintenance. The results revealed validation against measures of effectiveness and overall proved a substantial training and capability sustainment tool. The research indicated that the OA could be deployed operationally at the LaRC Compressor Station with an expectation of satisfactorily results and to obtain additional lessons learned prior to deployment at other LaRC Research Directorate Facilities. The research revealed projected cost and time savings.

  14. Operating experience

    McRae, L.P.; Six, D.E.

    1991-01-01

    In 1987, Westinghouse Hanford Company began operating a first-generation integrated safeguards system in the Plutonium Finishing Plant storage vaults. This Vault Safety and Inventory System is designed to integrate data into a computer-based nuclear material inventory monitoring system. The system gathers, in real time, measured physical parameters that generate nuclear material inventory status data for thousands of stored items and sends tailored report to the appropriate users. These data include canister temperature an bulge data reported to Plant Operations and Material Control and Accountability personnel, item presence and identification data reported to Material Control and Accountability personnel, and unauthorized item movement data reported to Security response forces and Material Control and Accountability personnel. The Westinghouse Hanford Company's experience and operational benefits in using this system for reduce radiation exposure, increase protection against insider threat, and real-time inventory control are discussed in this paper

  15. Operator companion

    Natalizio, A.; Anderson, J.W.D.; Sills, H.E.

    1988-01-01

    Abundant, cheap computing power has provided industry with a far greater opportunity than was available one or two decades ago to automate industrial processes and to improve the man-machine interface. Exciting innovations in knowledge representation methods arising from artificial intelligence research pave the way for advanced support systems for assisting plant operators. AECL has recognized the importance of knowledge based system technology, particularly expert systems, in the achievement of this objective and also, as a strategic technology to be fully exploited in the next generation of CANDU reactors. Operator Companion, an expert system intended to diagnose plant faults and advise the operator on appropriate restoring or corrective actions, is a major undertaking which is receiving support within the research and engineering groups of AECL

  16. Operative arthroscopy.

    Guhl, J F

    1979-01-01

    In a period of 20 months, over 200 patients (age ranged from high school students to middle-aged persons) with knee injuries were treated by operative arthroscopy. The majority of the injuries were incurred while the patients had been participating in athletic events, either competitive or recreational. Operative arthroscopy offers the advantage of shortened hospital stay, rapid rehabilitation, lack of disfiguring scar, and reduced costs. Patients are followed yearly after the first postoperative year. Improved long-term results from diagnostic and operative arthroscopy, as compared to conventional surgical procedures, are expected. The proof of those expectations will be determined in the next several years as this group of patients requiring partial meniscectomies or procedures for pathologic and degenerative conditions is reevaluated.

  17. Fundamental study on hydrogen storage with hydrogen absorbing alloys. Operating characteristics of storage tank; Suiso kyuzo gokin wo mochiita suiso chozo ni kansuru kiso kenkyu. Chozo yoki no dosa tokusei

    Sekiguchi, S.; Sekiguchi, N.; Tani, T. [Science University of Tokyo, Tokyo (Japan)

    1997-11-25

    Hydrogen absorption by a hydrogen storage (MH storage) is investigated for static characteristics, with a constant current applied to the hydrogen generator, and dynamic characteristics, with a fluctuating current applied to the same simulating actual insolation. In the experiment, alloy temperature (MH temperature) in the storage and a current for the generator are preset, and then automatic measurement is allowed to proceed at 10-second intervals of the differential pressure, hydrogen temperature in the piping, absolute pressure, MH temperature, room temperature, and water tank temperature. It is found as the result of the experiment that absorption performance is improved when the MH storage is cooled; that the mean absorption rate which is 1 without cooling increases to 1.62 at 7degC; that the mean absorption rate changes in proportion to the applied current (introduced hydrogen flow rate); that the rate which is 1 at 32A decreases to 0.53 that at 16A; that the absorption rate is dependent more on the current applied to the storage than the temperature of the heat exchanging medium; and that, even in the presence of fluctuation halfway in the applied current, the total absorption will be equal to a case of constant current application if the total amount of applied current is equal. 2 refs., 7 figs., 5 tabs.

  18. 14 CFR 25.253 - High-speed characteristics.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false High-speed characteristics. 25.253 Section...-speed characteristics. (a) Speed increase and recovery characteristics. The following speed increase and recovery characteristics must be met: (1) Operating conditions and characteristics likely to cause...

  19. Accelerator operations

    Anon.

    1980-01-01

    This section is concerned with the operation of both the tandem-linac system and the Dynamitron, two accelerators that are used for entirely different research. Developmental activities associated with the tandem and the Dynamitron are also treated here, but developmental activities associated with the superconducting linac are covered separately because this work is a program of technology development in its own right

  20. Operating Systems

    areas in which this type is useful are multimedia, virtual reality, and advanced scientific projects such as undersea exploration and planetary rovers. Because of the expanded uses for soft real-time functionality, it is finding its way into most current operating systems, including major versions of Unix and Windows NT OS.

  1. Peace Operations

    Lewis, William

    1995-01-01

    .... Indeed, despite the energetic leadership of Under Secretary-General Kofi R. Annan who directs the Department of Peacekeeping Operations, the organization has increasing difficulty in acquiring properly trained and equipped forces in time to intervene in conflict situations and humanitarian crises.

  2. Operational Circulars

    2003-01-01

    Operational Circular N° 4 - April 2003 Conditions for use by members of the CERN personnel of vehicles belonging to or rented by CERN - This circular has been drawn up. Operational Circular N° 5 - October 2000 Use of CERN computing facilities - Further details on the personal use of CERN computing facilities Operational Circular N° 5 and its Subsidiary Rules http://cern.ch/ComputingRules defines the rules for the use of CERN computing facilities. One of the basic principles governing such use is that it must come within the professional duties of the user concerned, as defined by the user's divisional hierarchy. However, personal use of the computing facilities is tolerated or allowed provided : a) It is in compliance with Operational Circular N° 5 and not detrimental to official duties, including those of other users; b) the frequency and duration is limited and there is a negligible use of CERN resources; c) it does not constitute a political, commercial and/or profit-making activity; d) it is not...

  3. Operation Context

    Stüben, Henning; Tietjen, Anne

    2006-01-01

    Abstract: This paper seeks to challenge the notion of context from an operational perspective. Can we grasp the forces that shape the complex conditions for an architectural or urban design within the notion of context? By shifting the gaze towards the agency of architecture, contextual analysis...

  4. Operational indicators

    2010-01-01

    The chapter presents the operational indicators related to budget, travel costs and tickets, the evolution of the annual program for regulatory inspection, the scientific production, requested patents and the numbers related to the production of the services offered by the Institution

  5. Subsonic aerodynamic characteristic of semispan commercial transport model with wing-mounted advanced ducted propeller operating in reverse thrust. [conducted in the Langley 14 by 22 foot subsonic wind tunnel

    Applin, Zachary T.; Jones, Kenneth M.; Gile, Brenda E.; Quinto, P. Frank

    1994-01-01

    A test was conducted in the Langley 14 by 22 Foot Subsonic Tunnel to determine the effect of the reverse-thrust flow field of a wing-mounted advanced ducted propeller on the aerodynamic characteristics of a semispan subsonic high-lift transport model. The advanced ducted propeller (ADP) model was mounted separately in position alongside the wing so that only the aerodynamic interference of the propeller and nacelle affected the aerodynamic performance of the transport model. Mach numbers ranged from 0.14 to 0.26; corresponding Reynolds numbers ranged from 2.2 to 3.9 x 10(exp 6). The reverse-thrust flow field of the ADP shielded a portion of the wing from the free-stream airflow and reduced both lift and drag. The reduction in lift and drag was a function of ADP rotational speed and free-stream velocity. Test results included ground effects data for the transport model and ADP configuration. The ground plane caused a beneficial increase in drag and an undesirable slight increase in lift. The ADP and transport model performance in ground effect was similar to performance trends observed for out of ground effect. The test results form a comprehensive data set that supports the application of the ADP engine and airplane concept on the next generation of advanced subsonic transports. Before this investigation, the engine application was predicted to have detrimental ground effect characteristics. Ground effect test measurements indicated no critical problems and were the first step in proving the viability of this engine and airplane configuration.

  6. Operating experience: safety perspective

    Piplani, Vivek; Krishnamurthy, P.R.; Kumar, Neeraj; Upadhyay, Devendra

    2015-01-01

    Operating Experience (OE) provides valuable information for improving NPP safety. This may include events, precursors, deviations, deficiencies, problems, new insights to safety, good practices, lessons and corrective actions. As per INSAG-10, an OE program caters as a fundamental means for enhancing the defence-in-depth at NPPs and hence should be viewed as ‘Continuous Safety Performance Improvement Tool’. The ‘Convention on Nuclear Safety’ also recognizes the OE as a tool of high importance for enhancing the NPP safety and its Article 19 mandates each contracting party to establish an effective OE program at operating NPPs. The lessons drawn from major accidents at Three Mile Island, Chernobyl and Fukushima Daiichi NPPs had prompted nuclear stalwarts to change their safety perspective towards NPPs and to frame sound policies on issues like safety culture, severe accident prevention and mitigation. An effective OE program, besides correcting current/potential problems, help in proactively improving the NPP design, operating and maintenance procedures, practices, training, etc., and thus plays vital role in ensuring safe and efficient operation of NPPs. Further it enhances knowledge with regard to equipment operating characteristics, system performance trends and provides data for quantitative and qualitative safety analysis. Besides all above, an OE program inculcates a learning culture in the organisation and thus helps in continuously enhancing the expertise, technical competency and knowledge base of its staff. Nuclear and Radiation Facilities in India are regulated by Atomic Energy Regulatory Board (AERB). Operating Plants Safety Division (OPSD) of AERB is involved in managing operating experience activities. This paper provides insights about the operating experience program of OPSD, AERB (including its on-line data base namely OPSD STAR) and its utilisation in improving the regulations and safety at Indian NPPs/projects. (author)

  7. Operation of staged membrane oxidation reactor systems

    Repasky, John Michael

    2012-10-16

    A method of operating a multi-stage ion transport membrane oxidation system. The method comprises providing a multi-stage ion transport membrane oxidation system with at least a first membrane oxidation stage and a second membrane oxidation stage, operating the ion transport membrane oxidation system at operating conditions including a characteristic temperature of the first membrane oxidation stage and a characteristic temperature of the second membrane oxidation stage; and controlling the production capacity and/or the product quality by changing the characteristic temperature of the first membrane oxidation stage and/or changing the characteristic temperature of the second membrane oxidation stage.

  8. Numerical investigation of biogas diffusion flames characteristics under several operation conditions in counter-flow configuration with an emphasis on thermal and chemical effects of CO2 in the fuel mixture

    Mameri, A.; Tabet, F.; Hadef, A.

    2017-08-01

    This study addresses the influence of several operating conditions (composition and ambient pressure) on biogas diffusion flame structure and NO emissions with particular attention on thermal and chemical effect of CO2. The biogas flame is modeled by a counter flow diffusion flame and analyzed in mixture fraction space using flamelet approach. The GRI Mech-3.0 mechanism that involves 53 species and 325 reactions is adopted for the oxidation chemistry. It has been observed that flame properties are very sensitive to biogas composition and pressure. CO2 addition decreases flame temperature by both thermal and chemical effects. Added CO2 may participate in chemical reaction due to thermal dissociation (chemical effect). Excessively supplied CO2 plays the role of pure diluent (thermal effect). The ambient pressure rise increases temperature and reduces flame thickness, radiation losses and dissociation amount. At high pressure, recombination reactions coupled with chain carrier radicals reduction, diminishes NO mass fraction.

  9. Characteristics of charcoal fines obtained by rapid pyrolysis process of elephant grass in fluidized bed in different operation conditions; Caracteristicas dos finos de carvao vegetal obtido pelo processo de pirolise rapida de capim elefante em leito fluidizado em diferentes condicoes de operacao

    Mesa Perez, Juan Miguel; Cortez, Luis Augusto Barbosa [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Fac. de Engenharia Agricola; Gomez, Edgardo Olivares; Rocha, Jose Dilcio [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Nucleo Interdisciplinar de Planejamento Energetico

    2004-07-01

    This paper presents a study about the effect of excess air and the inert fixed bed height upon the characteristics of fine charcoal particles and the main reactor parameters. The pyrolysis process is considered as a method to concentrate carbon in fine charcoal particles and a method to reduce oxygen content in the biomass.The study concludes that the operation point which gives the highest percentage if carbon fine charcoal particles and reduces the most the oxygen in biomass corresponds to a fixed bed height of 207 mm and excess air of 8%. (author)

  10. Role of magnetic resonance spectroscopy for the differentiation of recurrent glioma from radiation necrosis: A systematic review and meta-analysis

    Zhang, Hui [Department of Neurosurgery, Air Force General Hospital of the Chinese PLA, 30 Fucheng Road, Haidian District, Beijing 100142 (China); Department of Neurosurgery, Chinese PLA General Hospital, 28 Fuxing Road,Haidian District, Beijing 100853 (China); Ma, Li [Department of Anesthesiology, Beijing Military General Hospital, Beijing 100700 (China); Wang, Qun; Zheng, Xuan; Wu, Chen [Department of Neurosurgery, Chinese PLA General Hospital, 28 Fuxing Road,Haidian District, Beijing 100853 (China); Xu, Bai-nan, E-mail: bn_xu@yahoo.com [Department of Neurosurgery, Chinese PLA General Hospital, 28 Fuxing Road,Haidian District, Beijing 100853 (China)

    2014-12-15

    Purpose: Differentiating glioma recurrence from radiation necrosis remains a great challenge. We conducted a meta-analysis to evaluate the diagnostic quality of magnetic resonance spectroscopy (MRS) in differentiating glioma recurrence from radiation necrosis. Methods: Studies about evaluation of MRS for the differential diagnosis of glioma recurrence from radiation necrosis were systematically searched in PubMed, Embase and Chinese Biomedical databases up to May 4, 2014. The data were extracted to perform heterogeneity test, threshold effect test and to calculate sensitivity (SEN), specificity (SPE) and areas under summary receiver operating characteristic curve (SROC). Results: Eighteen articles comprising a total sample size of 455 patients (447 lesions) with suspected glioma recurrence after radiotherapy, met all inclusion and exclusion criteria, and were included in our meta-analysis. Quantitative synthesis of studies showed that the pooled SEN and SPE for Cho/Cr ratio were 0.83 (95% CI: 0.77, 0.89) and 0.83 (95% CI: 0.74, 0.90). The area under the curve (AUC) under the SROC was 0.9001. The pooled SEN and SPE for Cho/NAA ratio were 0.88 (95% CI: 0.81, 0.93) and 0.86 (95% CI: 0.76, 0.93). The AUC under the SROC was 0.9185. Conclusion: This meta-analysis shows that MRS alone has moderate diagnostic performance in differentiating glioma recurrence from radiation necrosis using metabolite ratios like Cho/Cr and Cho/NAA ratio. It is strongly recommended that MRS should combine other advanced imaging technologies to improve diagnostic accuracy. This article underlines the importance of implementing multimodal imaging trials and multicentre trials in the future.

  11. Characteristic of Rings. Prime Fields

    Schwarzweller Christoph

    2015-12-01

    Full Text Available The notion of the characteristic of rings and its basic properties are formalized [14], [39], [20]. Classification of prime fields in terms of isomorphisms with appropriate fields (ℚ or ℤ/p are presented. To facilitate reasonings within the field of rational numbers, values of numerators and denominators of basic operations over rationals are computed.

  12. Automobile characteristics historical data base

    1977-08-01

    A collection of data concerning the physical, operating, and performance characteristics of automobiles for the model years 1955, 1960, 1965, 1968, and 1970 to 1974. Data is to be added to the data base already established by DOT/TSC, for the 1975 mo...

  13. Site operations

    House, W.B.; Ebenhack, D.G.

    1989-01-01

    This chapter is a discussion of the management and operations practices used at the Barnwell Waste Management Facility in Barnwell, SC. The following topics are discussed: (1) Waste receiving and inspection, including manifest and certificates of compliance, radiological surveys, disposition of nonconforming items, and decontamination and disposition of secondary waste streams; (2) Waste disposal, including Title 10 CFR 61 requirements, disposal area evaluations, shipment offloading, container emplacement, and radiation protection; (3) Trench closure, including trench backfilling, trench capping, and permanent markers; (4) Site maintenance and stabilization, including trench maintenance, surface water management, and site closure activities; (5) Site monitoring programs, including operational monitoring, and environmental monitoring program; (6) Personnel training and qualifications, including basic training program, safety training program, special skills training, and physical qualifications; (7) Records management, including waste records, personnel training records, personnel dosimetry records, site monitoring records, trench qualification and construction records, and site drawings and stabilization records; (8) Site security; (9) Emergency response plans; and (10) Quality assurance

  14. Operators perspective

    Scragg, D.M.

    1991-01-01

    There are very few Energy from Municipal Waste processing plants in the U.K. Those which were built have usually been financed and operated by Local Authorities and are now in excess of 17 years old. The Environmental Protection Act and constraints on Public Sector spending have brought about fundamental changes in the approach taken to developing new schemes of this kind. The Public Sector and the Private Sector must work together. The investment in Mass Burning Incineration Schemes generating energy is high and the pressures to keep the waste disposal costs as low as possible mean that recovery of the investment needs to be spread over many years. For any Scheme to be successful and financially viable requires a long term commitment on the part of those involved. This paper sets out the key role which the Operating Contractor can play in this situation. (author)

  15. Operating Cigeo

    Launeau, F.

    2016-01-01

    The CIGEO facility dedicated to the geological disposal of high- and intermediate-level radioactive wastes will be composed of 2 parts: an underground facility at a depth of 500 m to dispose the waste packages in tunnels and a surface facility to take delivery of the wastes and prepare the packages. The underground facility will be built progressively and will cover a surface of 15 km 2 at the end of Cigeo operating-life. A large part of the surface facility (located a few km away from the waste reception place) will be dedicated to the works led deep underground to build the tunnels and will receive drilling cuttings. The article describes also the ramp and carts to lead waste packages underground. Most of the operations will be automated. The definitive closure of the tunnels will be made with swelling clay and concrete plugs. (A.C.)

  16. Operation Poorman

    Pruvost, N.; Tsitouras, J.

    1981-01-01

    The objectives of Operation Poorman were to design and build a portable seismic system and to set up and use this system in a cold-weather environment. The equipment design uses current technology to achieve a low-power, lightweight system that is configured into three modules. The system was deployed in Alaska during wintertime, and the results provide a basis for specifying a mission-ready seismic verification system

  17. Single-family home in Huenenberg, Switzerland - Pilot and demonstration installation: experience gained, energy balance, operational characteristics and comfort; Pilot- und Demonstrationsobjekt EFH Jurt in Huenenberg. Erfahrungen, Energiebilanz, Betriebscharakteristik und Komfort

    Huber, H.; Meierhans, D.

    2001-07-01

    This report made for the Swiss Federal Office of Energy (SFOE) presents the results of a study made at the University of Applied Science in Lucerne, Switzerland, on the improvements obtained as a result of the refurbishment of a single-family home in Huenenberg, Switzerland. The house, which was originally built in the 1960s, was refurbished in 1999 and well insulated. Its oil-fired heating system was replaced in 2000 with a wood-fired oven. The study presents the results of measurements made on the building concerning energy consumption and air-tightness etc., as well as on the efficiency of various components of the heating system (wood-fired oven, warm-air distribution system, heat recovery etc.). Weaknesses in the system that were thus discovered are listed and discussed. The increased fuel requirements caused by inefficiencies, non-appropriate user behaviour and the insufficient air-tightness of the building shell are quantified. General recommendations are made on the use of wood-fired ovens with warm-air heat distribution, in particular with respect to the insulation and air-tightness characteristics of the buildings.

  18. The main characteristics of the Saclay proton synchrotron, and the results obtained at the time of its setting in operation; Les caracteristiques principales du synchrotron a protons de Saclay et les resultats obtenus lors de la mise en route

    Bruck, H; Debraine, P; Levy-Mandel, R; Lutz, J; Maillet, R; Podliasky, I; Prevot, F; Taieb, J; Winter, S D [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    This paper consists on the one hand of a brief outline of the chief advantages of some characteristics peculiar to Saturne, particularly: the separation of the pole pieces from the body of the magnet, the structure of the vacuum chamber, the system of electrostatic deflectors of the injection optics and the HF cavity; and on the other hand of the difficulties encountered since starting up to improve the number of particles supplied by an induction electrode. The results obtained are also given, as for example the photographs taken in the propane chamber. (author)Fren. [French] La presente communication comporte d'une part un bref apercu des principaux avantages de quelques caracteristiques propres a Saturne et en particulier: la separation des pieces polaires de la masse de l'aimant, la structure de la chambre a vide, le systeme de deflecteurs electrostatiques de l'optique d'injection et la cavite HF; d'autre part, les difficultes rencontrees depuis la mise en route pour ameliorer le nombre de particules donne par une electrode d'induction, ainsi que les resultats obtenus comme par exemple les photographies prises dans la chambre a propane. (auteur)

  19. Sensor Characteristics Reference Guide

    Cree, Johnathan V.; Dansu, A.; Fuhr, P.; Lanzisera, Steven M.; McIntyre, T.; Muehleisen, Ralph T.; Starke, M.; Banerjee, Pranab; Kuruganti, T.; Castello, C.

    2013-04-01

    The Buildings Technologies Office (BTO), within the U.S. Department of Energy (DOE), Office of Energy Efficiency and Renewable Energy (EERE), is initiating a new program in Sensor and Controls. The vision of this program is: • Buildings operating automatically and continuously at peak energy efficiency over their lifetimes and interoperating effectively with the electric power grid. • Buildings that are self-configuring, self-commissioning, self-learning, self-diagnosing, self-healing, and self-transacting to enable continuous peak performance. • Lower overall building operating costs and higher asset valuation. The overarching goal is to capture 30% energy savings by enhanced management of energy consuming assets and systems through development of cost-effective sensors and controls. One step in achieving this vision is the publication of this Sensor Characteristics Reference Guide. The purpose of the guide is to inform building owners and operators of the current status, capabilities, and limitations of sensor technologies. It is hoped that this guide will aid in the design and procurement process and result in successful implementation of building sensor and control systems. DOE will also use this guide to identify research priorities, develop future specifications for potential market adoption, and provide market clarity through unbiased information

  20. Quantifying physical characteristics of wildland fuels using the fuel characteristic classification system.

    Cynthia L. Riccardi; Susan J. Prichard; David V. Sandberg; Roger D. Ottmar

    2007-01-01

    Wildland fuel characteristics are used in many applications of operational fire predictions and to understand fire effects and behaviour. Even so, there is a shortage of information on basic fuel properties and the physical characteristics of wildland fuels. The Fuel Characteristic Classification System (FCCS) builds and catalogues fuelbed descriptions based on...

  1. 14 CFR 23.253 - High speed characteristics.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false High speed characteristics. 23.253 Section... Requirements § 23.253 High speed characteristics. If a maximum operating speed VMO/MMO is established under § 23.1505(c), the following speed increase and recovery characteristics must be met: (a) Operating...

  2. Evaluation of nuclear power plant operator's ability

    Wei Li; He Xuhong; Zhao Bingquan

    2004-01-01

    Based on the quantitative research on nuclear power plant (NPP) operator's psychological characteristics and performance, the Borda's method of fuzzy mathematics combined with the character of operator's task is used to evaluate their abilities. The result provides the reference for operator's reliability research and psychological evaluation. (author)

  3. The human factor in nuclear reactor operation

    Bertron, L.

    1982-05-01

    The principal operating characteristics of nuclear power plants are summarized. A description of major hazards relating to operator fallibility in normal and abnormal operating conditions is followed by a specific analysis of control room hazards, shift organization and selection and training of management personnel

  4. Operator errors

    Knuefer; Lindauer

    1980-01-01

    Besides that at spectacular events a combination of component failure and human error is often found. Especially the Rasmussen-Report and the German Risk Assessment Study show for pressurised water reactors that human error must not be underestimated. Although operator errors as a form of human error can never be eliminated entirely, they can be minimized and their effects kept within acceptable limits if a thorough training of personnel is combined with an adequate design of the plant against accidents. Contrary to the investigation of engineering errors, the investigation of human errors has so far been carried out with relatively small budgets. Intensified investigations in this field appear to be a worthwhile effort. (orig.)

  5. Your Lung Operation: After Your Operation

    Full Text Available ... Lung Operation After Your Operation Your Discharge and Recovery Complete Video After Your Operation Guidance for after ... Your Lung Operation Read Next Your Discharge and Recovery Back to Top Find A Surgeon Find A ...

  6. Evaluation of Blood-Based Antibody Rapid Testing for HIV Early Therapy: A Meta-Analysis of the Evidence

    Xiaojie Huang

    2018-06-01

    Full Text Available BackgroundWestern blot (WB assay is considered the gold standard test for HIV infection confirmation. However, it requires technical expertise and is quite time-consuming. WHO recommends blood-based rapid diagnosis to achieve same-day test and treatment. However, this rapid testing strategy has not been promoted worldwide due to inadequate research evaluating the effectiveness of rapid tests (RTs as an alternative confirmatory HIV test for WB. This study aims to compare the diagnostic performance of rapid HIV tests compared with WB.MethodsPubMed and Web of Science were searched for publications on rapid HIV tests using blood specimen. A meta-analysis was performed to quantitatively evaluate the diagnostic performance of rapid HIV tests compared with the WB assay in terms of pooled sensitivity, specificity, area under summary receiver operating characteristic (SROC curve, and diagnostic odds ratio (DOR.ResultsTwenty articles involving 27,343 fresh specimens for rapid HIV tests were included in the meta-analysis. Regarding Capillus HIV-1/HIV-2, the pooled sensitivity, specificity, area under SROC curve, and DOR derived from six studies were 0.999 (95% CI, 0.956–1.000, 0.999 (95% CI, 0.991–1.00, 1.00 (95% CI, 0.99–1.00, and 1.0 × 106 (95% CI, 2.6 × 104–3.9 × 107 compared with the WB assay, respectively. With respect to Determine HIV-1/2, the pooled sensitivity, specificity area under SROC, and DOR derived from eight studies were 1.00 (95% CI, 0.789–1.000, 0.992 (95% CI, 0.985–0.996, 1.00 (95% CI, 0.99–1.00, and 1.8 × 106 (95% CI 406.049–7.8 × 109 compared with the WB assay, respectively. Regarding two-step serial RTs, the pooled sensitivity, specificity area under SROC, and DOR derived from eight studies were 0.998 (95% CI, 0.991–1.000, 0.998 (95% CI, 0.994–0.999, and 1.00 (95% CI 0.99–1.00 compared with the WB assay, respectively.ConclusionOur meta-analysis results may provide evidenced-based support

  7. Construction and operating characteristics of flexible Geiger counters; Caracteristiques de construction et d'utilisation de compteurs Geiger flexibles; Konstruktsionnaya i operativnaya kharakteristiki gibkikh schetchikov Gejgera; Construccion y caracteristicas de funcionamiento de contadores Geiger flexibles

    Richter, H G; Ballard, L F [Research Triangle Institute, Durham, NC (United States)

    1962-04-15

    A method has been developed for constructing flexible Geiger counters in a wide range of lengths and diameters. The counters are quite flexible: a 3-cm diam. counter can be bent to a circle of 5 cm radius. Using Q-gas (98.3% helium, 1.7% n-butane) as the counting medium, plateaux are several hundred volts long with 3% slopes and are independent of the counter configuration. Counters are constructed from tubing having a polyvinyl-chloride formulation (PVC-744 - Alpha Wire Corp.). Short segments of the plastic tubing (length {approx} 3 times the tube diameter) are slipped over a coarsely threaded aluminium mandrel. Wire is wrapped tightly in the threads and the whole is placed in a 110{sup o}C oven for 20 min. After cooling, the corrugated plastic segment is removed from the mandrel. This corrugation prevents the collapse of the tubing when it is coiled. A polystyrene disk, perforated with relatively large holes near the periphery for gas flow and having a 0.6-mm hole in the centre for the anode, is fastened in one end of each segment. By threading the segments thus prepared on a 3-mil tungsten anode and slipping one end of each segment over the adjacent segment and securing them with an adhesive, a counter of any desired length can be built up. Glass end-pieces for attaching the anode ends and for admitting and exhausting the flow gas are attached. A bare copper wire spiralled in the grooves of the counter makes a satisfactory external cathode which operates in the manner observed by MAZE. A 3-cm diam. counter, 1 m long, either linear or coiled, has a plateau beginning at 1400 V and extending beyond 1750 V with a 2.9% slope. Counting rates in excess of 300000 counts/min with little coincidence loss have been observed. Since the counter is actually a series of short Geiger counters and the discharge does not spread beyond the polystyrene spacer disks, adjacent counter segments operate independently. Pulse heights are greater than 50 mV. (author) [French] On a mis au

  8. Reliability Characteristics of Power Plants

    Zbynek Martinek

    2017-01-01

    Full Text Available This paper describes the phenomenon of reliability of power plants. It gives an explanation of the terms connected with this topic as their proper understanding is important for understanding the relations and equations which model the possible real situations. The reliability phenomenon is analysed using both the exponential distribution and the Weibull distribution. The results of our analysis are specific equations giving information about the characteristics of the power plants, the mean time of operations and the probability of failure-free operation. Equations solved for the Weibull distribution respect the failures as well as the actual operating hours. Thanks to our results, we are able to create a model of dynamic reliability for prediction of future states. It can be useful for improving the current situation of the unit as well as for creating the optimal plan of maintenance and thus have an impact on the overall economics of the operation of these power plants.

  9. Development of transportation operations requirements

    Grady, S.T.; Best, R.E.; Danese, F.L.; Peterson, R.W.; Pope, R.B.

    1990-01-01

    Transport conditions at various utility sties vary dramatically in terms of characteristics at and near the site, requirements, administrative procedures, and other factors. Continuation of design efforts for the OCRWM transportation operations system requires that the operating requirements for the transportation system -- quantity of fuel per unit time per site -- be identified so that the effect the variations have on the system can be accommodated. The approach outlined in this paper provides for an identification of specific sites, evaluation of shipment capabilities at each site, and integration of the sites into multi-site shipping campaigns to scope the logistics management problem for the transportation operations system. 1 fig., 1 tab

  10. 46 CFR 109.564 - Maneuvering characteristics.

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Maneuvering characteristics. 109.564 Section 109.564 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Miscellaneous § 109.564 Maneuvering characteristics. (a) The master or person in charge of each...

  11. Operational Law Handbook,2007

    2007-01-01

    ... & SOFAs, legal assistance, combating terrorism, domestic operations, noncombatant evacuation operations, special operations, civil affairs, air, sea, and space law, detainee operations, reserve...

  12. RF Characteristics of Mica-Z Wireless Sensor Network Motes

    Koh, Swee J

    2006-01-01

    ... network characteristics. Link-break and re-association distances with their corresponding RF power measurements were recorded to determine the Mica-Z s range characteristics under these different operating environments...

  13. Operant Variability and Voluntary Action

    Neuringer, Allen; Jensen, Greg

    2010-01-01

    A behavior-based theory identified 2 characteristics of voluntary acts. The first, extensively explored in operant-conditioning experiments, is that voluntary responses produce the reinforcers that control them. This bidirectional relationship--in which reinforcer depends on response and response on reinforcer--demonstrates the functional nature…

  14. Development of nuclear plant Operation Management System

    Koide, I.; Okada, T.; Ishida, K. [Chubu Electric Power Co. Inc., Nagoya (Japan)

    1998-09-01

    Recently it has become more important to detect a change in operational characteristics and to take appropriate corrective actions before it deteriorates to an incident in nuclear power plants. Therefore, aiming at earlier detection of a tendency change, swifter corrective actions and more effective application of operational data, we have developed Operation Management System which automatically acquires, accumulates and observes operational data of Hamaoka Nuclear Power Station through cycles. (author)

  15. Development of nuclear plant Operation Management System

    Koide, I.; Okada, T.; Ishida, K.

    1998-01-01

    Recently it has become more important to detect a change in operational characteristics and to take appropriate corrective actions before it deteriorates to an incident in nuclear power plants. Therefore, aiming at earlier detection of a tendency change, swifter corrective actions and more effective application of operational data, we have developed Operation Management System which automatically acquires, accumulates and observes operational data of Hamaoka Nuclear Power Station through cycles. (author)

  16. Characteristics of the Romanian energy market

    Stet, M.

    2017-05-01

    This paper highlights the main characteristics of the energy market in Romania. Starting from the mode of organization and operation of the electricity market, there are revealed prices and tariffs for electricity for different categories of customers and their evolution in time. There are pointed also ways of setting electricity prices and tariffs, taking into account the expenditures actually recorded by economic operators.

  17. Operator training for the abnormal

    Marzec, R.J.

    1977-01-01

    Training of nuclear power plant control room operators, on actions to be taken for an abnormal event, has classically been limited to discussion, on-shift and/or during requalification training classes, of symptoms, logical thought processes, systems analysis, and operator experience. The prerequisites for these discussions are a common technical vocabulary, and a minimum basic comprehension of nuclear power plant fundamentals, plant component theory of operation, system configuration, system control philosophy and operating procedures. Nuclear power plant control room operators are not the only personnel who are or should be involved in these discussions. The shift supervisors, operations management, and auxiliary equipment operators require continuing training in abnormal operations, as well. More in-depth training is necessary for shift supervisors and control room operators. The availability of vendor simulators has improved the effectiveness of training efforts for these individuals to some extent by displaying typical situations and plant performance characteristics and by providing a degree of ''hands on'' experience. The evolution of in-depth training with these simulators is reviewed

  18. Nuclear design characteristics of SMART

    Lee, Chung Chan; Park, Sang Yoon; Lee, Ki Bog; Zee, Sung Quun; Chang, Moon Hee [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1998-12-31

    Nuclear design bases for System-Integrated Modular Advanced ReacTor(SMART) core are presented. Based on the proposed design bases, a SMART core loading pattern is constructed and its nuclear characteristics are studied. The proposed core loading pattern satisfies 3-year cycle length and soluble boron-free operation requirements at any time during the cycle. 10 refs., 2 figs., 1 tab. (Author)

  19. Nuclear design characteristics of SMART

    Lee, Chung Chan; Park, Sang Yoon; Lee, Ki Bog; Zee, Sung Quun; Chang, Moon Hee [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1999-12-31

    Nuclear design bases for System-Integrated Modular Advanced ReacTor(SMART) core are presented. Based on the proposed design bases, a SMART core loading pattern is constructed and its nuclear characteristics are studied. The proposed core loading pattern satisfies 3-year cycle length and soluble boron-free operation requirements at any time during the cycle. 10 refs., 2 figs., 1 tab. (Author)

  20. Forecasting characteristics of flood effects

    Khamutova, M. V.; Rezchikov, A. F.; Kushnikov, V. A.; Ivaschenko, V. A.; Bogomolov, A. S.; Filimonyuk, L. Yu; Dolinina, O. N.; Kushnikova, E. V.; Shulga, T. E.; Tverdokhlebov, V. A.; Fominykh, D. S.

    2018-05-01

    The article presents the development of a mathematical model of the system dynamics. Mathematical model allows forecasting the characteristics of flood effects. Model is based on a causal diagram and is presented by a system of nonlinear differential equations. Simulated characteristics are the nodes of the diagram, and edges define the functional relationships between them. The numerical solution of the system of equations using the Runge-Kutta method was obtained. Computer experiments to determine the characteristics on different time interval have been made and results of experiments have been compared with real data of real flood. The obtained results make it possible to assert that the developed model is valid. The results of study are useful in development of an information system for the operating and dispatching staff of the Ministry of the Russian Federation for Civil Defence, Emergencies and Elimination of Consequences of Natural Disasters (EMERCOM).