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Sample records for optimum operation conditions

  1. ANALYSIS OF OPTIMUM OPERATING MODES OF POWER TRANSFORMERS UNDER OPERATING CONDITIONS

    Directory of Open Access Journals (Sweden)

    I. V. Khomenko

    2016-12-01

    Full Text Available Purpose. The study of parallel operation optimal modes of transformer equipment for a variety of operating conditions: same or different types of transformers, with or without reactive power flows. Methodology. Losses of energy in transformers make 30 % of all losses. Therefore the choice of the economically justified parallel operation of transformers is effective action to reduce losses. Typically, in the calculations of reactive power flows in the transformers are not taken into account. It is interesting to analyze the optimal operating conditions of transformers with and without reactive power flows. Results. Calculations for transformers in distribution networks showed that the inclusion of reactive power flows in transformers significant impact on the calculated optimum regimes of transformers.

  2. Mapping of optimum operating condition for LiBr–water refrigeration cycles

    Indian Academy of Sciences (India)

    NILESH A MALI; SUNIL S BHAGWAT

    2017-02-01

    In this work, optimum operating condition maps are generated covering wide ranges of refrigeration and sink temperatures for single- and double-effect LiBr–water vapour absorption refrigeration cycle. These optimum condition maps will be useful to choose optimum operating conditions while designing LiBr–water cycle for desired applications. Methodology for generating such maps is discussed in detail, which can also beused for other absorption refrigeration cycles with various working fluids. Three configurations of LiBr–water absorption refrigeration cycles, single effect, double-effect series flow and double-effect parallel flow, are analysed with the most accurate thermodynamic property correlation available in the literature. Sensitivity of cycle performance to various operating variables such as generator, absorber and condenser temperatures is determined. Second law analysis shows that when a higher temperature heat source is available, double-effect cycles are more effective over single effect as they have higher coefficient of performance.

  3. Optimum operation conditions of nitrogen and phosphorus removal by a biofilm-activated-sludge system

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    In the biofilm and activated sludge combined system, denitrifying bacteria attached on the fibrous carriers in the anoxic tank, while the sludge containing nitrifying and phosphorus removal bacteria was only recirculated between the aerobic and anaerobic tanks. Therefore, the factors affected and restricted nitrification, denitrification and phosphorus removal in a traditional A/A/O process were resolved. This paper describes the optimum operation conditions for nitrogen and phosphorus removal using this system.

  4. Optimum Operating Conditions for Epoxidation Reaction of Jojoba and Castor Oils

    Directory of Open Access Journals (Sweden)

    El-Adly R. A

    2014-03-01

    Full Text Available The goal of this paper is to determine the best set of parameters such as, glacial acetic acid to ethylenic unsaturation mole ratio (acid/ethylene, hydrogen peroxide to ethylenic unsaturation mole ratio (H2O2/ethylene and temperature on epoxidation conversion based on experimental results, with respect to time. The effect of these parameters has been studied in a separate set of experiments. Their ranges were as follows: 0.2-0.8Wt%, 0.75-3Wt%, and 40oC-80oC respectively. Six models have been introduced to indicate the effect of these three variables on conversion for both jojoba and castor oil, and the prediction abilities of the resultant models were tested. Regression analysis is used to extract the introduced non linear models. In addition, two new correlations have been introduced to incorporate all the studied variables and their effect on conversion simultaneously for both jojoba and castor oil. An optimization program has been introduced to determine the optimum operating conditions for maximum conversion for both jojoba and castor oil. The study shows that, the maximum conversion for epoxidized jojoba oil (66% could be achieved at acid/ethylene ratio: 0.4, H2O2/ethylene ratio: 1.44; temp: 66.5 and time is 8hr. While the maximum conversion for epoxidized castor oil (53.24% could be achieved at acid/ethylene ratio: 0.37; H2O2/ethylenes ratio: 1.32; temp: 61 and time is 8hr. the model results are strongly agreed with the experimental results.

  5. Optimum thermal sizing and operating conditions for once through steam generator

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Kunwoo; Ju, Kyongin; Im, Inyoung; Kim, Eunkee [KEPCO Engineering and Construction Company., Inc., Daejeon (Korea, Republic of)

    2014-10-15

    The steam generator is designed to be optimized so as to remove heat and to produce steam vapor. Because of its importance, theoretical and experimental researches have been performed on forced convection boiling heat transfer. The purpose of this study is to predict the thermal behavior and to perform optimum thermal sizing of once through steam generator. To estimate the tube thermal sizing and operating conditions of the steam generator, the analytical modeling is employed on the basis of the empirical correlation equations and theory. The optimized algorithm model, Non-dominated Sorting Genetic Algorithm (NSGA)-II, uses for this analysis. This research is focused on the design of in-vessel steam generator. An one dimensional analysis code is developed to evaluate previous researches and to optimize steam generator design parameters. The results of one-dimensional analysis need to be verified with experimental data. Goals of multi-objective optimization are to minimize tube length, pressure drop and tube number. Feedwater flow rate up to 115.425kg/s is selected so as to have margin of feedwater temperature 20 ..deg. C. For the design of 200MWth once through steam generator, it is evaluated that the tube length shall be over 12.0m for the number of tubes, 2500ea, and the length of the tube shall be over 8.0m for the number of tubes, 4500ea. The parallel coordinates chart can be provided to determine the optimal combination of number of tube, pressure drop, tube diameter and length.

  6. The optimum operating conditions of the phased double-rotor facility at the ET-RR-1 reactor

    Energy Technology Data Exchange (ETDEWEB)

    Naguib, K.; Habib, N.; Wahba, M.; Kilany, M.; Adib, M. [National Research Centre, Cairo (Egypt). Reactor and Neutron Physics Dept.

    1997-02-07

    A pulsed neutron polyenergetic thermal beam at ET-RR-1 is produced by a phased double-rotor facility. One of the rotors has two diametrically opposite curved slots, while the second is designed to operate as a rotating collimator. The dimensions of the phased rotating collimator are selected to match the curved slot rotor. The calculated collimator transmissions at different operating conditions are found to be in good agreement with the experimental ones. The optimum operating conditions of the double-rotor facility are deduced. The calculations were carried out using a computer program RCOL. The RCOL was designed in FORTRAN-77 to operate on PCs. (author).

  7. Optimum operating conditions for an adsorption cryocooler: a case of activated carbon + nitrogen system

    Energy Technology Data Exchange (ETDEWEB)

    Radhika Rani Rao [Don Bosco Institute of Technology, Bangalore (India). Dept. of Physics; Madhu Prasad [ISRO Satellite Centre, Bangalore (India). Thermal Systems Group; Kandadai Srinivasan [Indian Institute of Science, Bangalore (India). Dept. of Mechanical Engineering

    2005-03-01

    Adsorption cryocoolers are among the possible options for obtaining cryogenic temperatures, in particular for small cooling capacity applications such as cooling of infra red detectors. They need to be optimized for liquid yield. The performance of thermal compressors therein pivots around the adsorption characteristics of the adsorbent + adsorbate combination and how effectively one could pack requisite amounts of adsorbent into a given volume of the compressor housing. In addition, the overall performance of the cooler is a function of limits of operating temperatures and pressures across the compressor. This paper proposes a performance indicator-the product of liquid yield and the uptake efficiency of the compressor - and evaluates its values for various possible operating conditions for one specimen of activated carbon. It is shown that there is a limited domain of operation and that there is a condition of best performance within that domain. (author)

  8. On optimum temperature conditions for operation of portable aliminum-air batteries

    Directory of Open Access Journals (Sweden)

    Vlasenko Maxim

    2017-01-01

    Full Text Available For construction of portable aluminium-air batteries (AABs for field applications the data on performance of such batteries at low temperatures are necessary. Such experimental data are presented in this article. Lower temperature limit for effective operation of portable AABs is estimated. Possibility of AABs self-heating to the desired temperature is also considered.

  9. Optimum operating conditions of a solar cell panel and prediction of solar radiation in Sanaa, Yemen

    Energy Technology Data Exchange (ETDEWEB)

    Khogali, A.; Ramadan, M.R.I.

    1982-01-01

    The performance of a solar cell panel is evaluated under the actual conditions prevailing in Sanaa, Yemen. The availability of solar energy is predicted using an empirical formula (with the number of hours of sunshine as an input). The results agree with measurements made using a pyranometer over a period of 1 year with a deviation of less than 10% and reveal a high annual insolation in Sanaa. The power output of the panel is linearly dependent on the solar irradiation and on the total cell conversion efficiency. The total cell conversion efficiency is highly sensitive to variation in temperature. A drop of 4% in the efficiency was detected at midday temperatures. If the panel is tilted towards the Equator in the winter months, the power output can be increased by 16%. For such a low latitude (15/sup 0/N) the angle of tilt may be fixed in order to simplify construction and to reduce costs. An estimate is given to the active cell area required to supply an energy of 1 kWh.

  10. Optimum Operation Condition on Distributed Power Supply System with Micro Gas Turbine/Solid Oxide Fuel Cell

    Science.gov (United States)

    Suzuki, Hiroshi; Yamada, Miki; Usui, Hiromoto; Komoda, Yoshiyuki

    In order to find the optimum operation condition of a distributed power supply system of 30kW class micro gas turbine (MGT) and solid oxide fuel cell (SOFC) hybrid system with the combination of line electric power and supplied gas, a system analysis has been performed. In this study, an absorption chiller and a boiler were mounted to utilize the exhausted heat from the MGT/SOFC system. The time variation of energy consumption in 24 hours for house and market models was taken into consideration for the calculation of the energy saving ratio of the present system. The operation ratio defined with the ratio of power supply of MGT/SOFC system to the power required at the peak load was changed as a parameter. From the comparison with the system using line power and gas, it is found that the present system shows high energy saving ratio around 0.4 of the operation ratio, but the energy saving ratio severely decreases in the range of high operation ratio. In this study, it is revealed that the thermal storage system effectively improves the energy saving ratio especially for the house model in winter season.

  11. Study on Performance of Infectious Waste Sterilizing Set in Kashan Shahid Beheshti Hospital and Determination of its Optimum Operating Condition

    Directory of Open Access Journals (Sweden)

    M Heidari

    2012-03-01

    Full Text Available Background and Objectives; Autoclaving is one of  the methods which sterilizes infectious solid wastes. Since variety of parameters such as temperature, time, and pressure influence autoclave performance, this study was carried out to evaluate the parameters and set optimum condition for the autoclave apparatus  applied in Shahid Beheshti Hospital in Kashan.Materials and Methods: In this descriptive-analytical study, the performance of subjected autoclave was surveyed based on biological index and through setting 144 tests. Variables were packaging type in two groups (open and wrapped, loading type in three groups (light, medium and heavy, and four temperature-time features in fixed pressure equal to 101 kpa. Biological index was ATCC 7953 which contained Stearotermophilus Geobacillus spores. Finally obtained results were analyzed by Chi-Square test.Results: The results of statistical test showed that there isnt any meaningful relation between packaging type of waste, system loading, and efficiency of sterilization(P>0.05,while meaningful relation was found between system performance and variety states of temperature-time feature(P<0.05, illustrating temperature and time effects in fixed pressure on sterilization of solid waste.Conclusion: Based on the results, the best autoclave operational condition for sterilizing infectious solid wastes are: temperature-time equal to 10 min-140°C and 15 min-134°C in fixed pressure of 101 kpa, respectively. It was also revealed that temperature-time condition suggested by manufactory, i.e. 20min-121°C, is not sufficient for complete sterilization of solid waste.

  12. Determination of optimum operating conditions for production of polyhydroxybutyrate by activated sludge submitted to dynamic feeding regime

    Institute of Scientific and Technical Information of China (English)

    QU Bo; LIU JunXin

    2009-01-01

    Polyhydroxybulyrate (PHB) was produced by activated sludge in a two-stage process. In the first stage, the sludge with high storage potential was enriched in a sequencing batch reactor (SBR) operated by a dynamic feeding regime. The biosynthesis of PHB was sequentially accomplished in a batch reactor in the second stage. This article focused on the optimization of PHB content by evaluating the effects of three critical factors: Dissolved oxygen, pH and food-to-microorganism (F/M) ratio in the batch reactor. The results showed that the rate of substrate uptake, as well as the yield and content of PHB increased with the increase of dissolved oxygen concentration. The control of pH was not necessary under the weak alkaline condition for improvement of PHB content, except for the case in which the pH value was out of rang of 1.0 to 10.0. The enhanced F/M ratio favored PHB accumulation in the range of 1.0 to 4.5 C-mmol/C-mmol and the highest PHB content, 64%, was achieved at 4.5 C-mmol/O-mmol. When F/M ratio was enhanced to 6.0 C-retool/C-retool, the phenomenon of utilizing simultaneously intracellular PHB and external substrate by sludge was observed, which resulted in a sharp decrease of PHB con-tent. The microscopic observation clearly confirmed that dynamic feeding regime was effective for selecting and enriching the sludge with a high storage potential.

  13. Optimum Operational Parameters for Yawed Wind Turbines

    Directory of Open Access Journals (Sweden)

    David A. Peters

    2011-01-01

    Full Text Available A set of systematical optimum operational parameters for wind turbines under various wind directions is derived by using combined momentum-energy and blade-element-energy concepts. The derivations are solved numerically by fixing some parameters at practical values. Then, the interactions between the produced power and the influential factors of it are generated in the figures. It is shown that the maximum power produced is strongly affected by the wind direction, the tip speed, the pitch angle of the rotor, and the drag coefficient, which are specifically indicated by figures. It also turns out that the maximum power can take place at two different optimum tip speeds in some cases. The equations derived herein can also be used in the modeling of tethered wind turbines which can keep aloft and deliver energy.

  14. Optimum Operating Conditions of (PbxX1−x(ZryTizY1−y−z Piezoelectric Transducer for Vibrational Energy Harvesting Applications

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    Funda Demir

    2016-01-01

    Full Text Available The electrical energy production capability of bimorph (PbxX1-x(ZryTizY1-y-z fiber composite piezoelectric transducer has been investigated for energy harvesting applications. The material has been analyzed under different frequencies, bending amounts, and temperatures. The operating conditions for maximum electrical energy outcome have been determined. The natural frequencies of oscillations in the macro dimensions have been found to be inversely proportional to the length of the material. On the other hand, the voltage output with respect to the oscillation frequency exhibits an interesting behavior such that the characteristic curve shifts to higher frequencies as the bending radius is decreased. This behavior has been interpreted as a result of possible overtone transitions of the oscillations to a stiffer mode. The increasing temperature has been observed to have a negative effect on the piezoelectric energy harvesting property. When the determined optimum conditions were utilized, the amount of electrical energy stored in 6300 s by an energy harvester circuitry has been found to be 0.8 J.

  15. Optimum conditions for microbial carbonate precipitation.

    Science.gov (United States)

    Okwadha, George D O; Li, Jin

    2010-11-01

    The type of bacteria, bacterial cell concentration, initial urea concentration, reaction temperature, the initial Ca(2+) concentration, ionic strength, and the pH of the media are some factors that control the activity of the urease enzyme, and may have a significant impact on microbial carbonate precipitation (MCP). Factorial experiments were designed based on these factors to determine the optimum conditions that take into consideration economic advantage while at the same time giving quality results. Sporosarcina pasteurii strain ATCC 11859 was used at constant temperature (25°C) and ionic strength with varying amounts of urea, Ca(2+), and bacterial cell concentration. The results indicate that the rate of ureolysis (k(urea)) increases with bacterial cell concentration, and the bacterial cell concentration had a greater influence on k(urea) than initial urea concentration. At 25 mM Ca(2+) concentration, increasing bacterial cell concentration from 10(6) to 10(8)cells mL⁻¹ increased the CaCO(3) precipitated and CO(2) sequestrated by over 30%. However, when the Ca(2+) concentration was increased 10-fold to 250 mM Ca(2+), the amount of CaCO(3) precipitated and CO(2) sequestrated increased by over 100% irrespective of initial urea concentration. Consequently, the optimum conditions for MCP under our experimental conditions were 666 mM urea and 250 mM Ca(2+) at 2.3×10⁸ cells mL⁻¹ bacterial cell concentration. However, a greater CaCO(3) deposition is achievable with higher concentrations of urea, Ca(2+), and bacterial cells so long as the respective quantities are within their economic advantage. X-ray Diffraction, Scanning Electron Microscopy and Energy Dispersive X-ray analyzes confirmed that the precipitate formed was CaCO(3) and composed of predominantly calcite crystals with little vaterite crystals.

  16. Techniques for evaluating optimum data center operation

    Science.gov (United States)

    Hamann, Hendrik F.; Rodriguez, Sergio Adolfo Bermudez; Wehle, Hans-Dieter

    2017-06-14

    Techniques for modeling a data center are provided. In one aspect, a method for determining data center efficiency is provided. The method includes the following steps. Target parameters for the data center are obtained. Technology pre-requisite parameters for the data center are obtained. An optimum data center efficiency is determined given the target parameters for the data center and the technology pre-requisite parameters for the data center.

  17. Fluidization and Optimum Backwashing Conditions in Multimedia Filter

    Directory of Open Access Journals (Sweden)

    Rusul Naseer

    2011-11-01

    Full Text Available The aim of this study is to study and evaluate the fluidization and optimum backwashing conditions which include minimum fluidization velocity, expanded bed porosity and energy dissipation under different operation conditions with different media grain size in multimedia filter. Theoretical and experimental study was performed to evaluate the backwashing process of multimedia filter by fluidizing the filter media whereas backwashing Process was carried out by a pilot laboratory filter of multimedia filter column using different characteristics of filters media. A model was built to predict the expanded bed filter and the fluidized porosity. The result showed that proposed model give a good fit with observed data. It is observed that smaller grain sand was needed a lower value of backwash rate then of the higher grain sand to rise the filter media and the fixed porosity 0.51 will expand to the optimum fluidized porosity 0.704 for a bigger value of grain sand while the smaller value of grain diameter 0.5 mm was expanded to the optimum fluidized porosity 0.68. It is also concluded that the effluent turbidity and detachment rate of deposited material decreases with increasing backwashing time and increasing total backwash rate. It is also concluded that the energy dissipation and the velocity gradient have a dominant mechanism of filter cleaning.

  18. Optimum reliable operation of water distribution networks by ...

    African Journals Online (AJOL)

    Optimum reliable operation of water distribution networks by minimising energy cost and chlorine dosage. ... In this study, multi-objective optimisation of water distribution network performance in 3 different scenarios was ... Article Metrics.

  19. Optimum operating regimes of common paramagnetic refrigerants

    CERN Document Server

    Wikus, P; Figueroa-Feliciano, E

    2011-01-01

    Adiabatic Demagnetization Refrigerators (ADRs) are commonly used in cryogenic laboratories to achieve subkelvin temperatures. ADRs are also the technology of choice for several space borne instruments which make use of cryogenic microcalorimeters or bolometers {[}1-4]. For these applications, refrigerants with high ratios of cooling capacity to volume, or cooling capacity to mass are usually required. In this manuscript, two charts for the simple selection of the most suitable of several common refrigerants (CAA, CMN, CPA, DGG, FAA, GGG, GLF and MAS) are presented. These graphs are valid for single stage cycles. The selection of the refrigerants is uniquely dependent on the starting conditions of the refrigeration cycle (temperature and magnetic field density) and the desired final temperature. Only thermodynamic properties of the refrigerants have been taken into account, and other important factors such as availability and manufacturability have not been considered. (C) 2011 Elsevier Ltd. All rights reserve...

  20. The research on the optimum working conditions of photoconductive antenna

    Science.gov (United States)

    Shi, Wei; Dai, Yang; Zhang, Like; Yang, Lei; Yan, Zhijin; Chen, Suguo; Hou, Lei

    2015-11-01

    The photoconductive antenna (PCA) is one of the most common devices to generate terahertz (THz) wave, whose radiation efficiency is largely determined by the working conditions. In order to improve the power of THz wave, the influence of pump laser and bias voltage on the intensity of the THz wave radiated by PCA was studied through experiment and the optimum working conditions of PCA was obtained through the theoretical analysis, these are the maximum safe voltage and saturated laser energy. Only under the optimum conditions can the signal-to-noise ratio(SNR)of THz wave radiated by PCA be the highest and the PCA would not breakdown.

  1. Optimum Condition Selection of Xylitol Candida tropicaiis Conversion Production

    Institute of Scientific and Technical Information of China (English)

    JIA Chan-yuan; YANG Ping-ping

    2011-01-01

    [Objective]The aim was to select the optimum conditions of xylitol Candida tropicalis conversion production.[Method]The effect of cell culture time, conversion time, conversion pH value,conversion initial sugar concentration, speed and inoculation rate were determined respectivaiy.[Result]Optimum fermentation conditions were obtained as follows: cell culture 16 h, conversion time 10 h, conversion pH value 5.5,conversion initial sugar concentration 20 g/L, conversion shaking speed 150 r/min, inoculation rate 10% (volume ratio).The yield of xylitol has increased to 90%.[Conclusion]This study had provided basis for the further study on xylitol.

  2. [Study on optimum extraction conditions of alkaloids from Pinellia ternate].

    Science.gov (United States)

    Zeng, Jianhong; Peng, Zhengsong; Mao, Zicheng; Wei, Shuhong

    2003-05-01

    The optimum extraction conditions of alkaloids from Pinellia ternate (Thunb.) Breit were studied by orthogonal test. The results showed that the highest extraction rate of the alkaloids could be obtained by smashing the material in 60 (sieve number) of fragmentation and socking the material in 2.575 mol/L ammonia water, extracting alkaloids with 18 times as much chlorolform at room temperature for 25 hours. The highest extraction rate of alkaloids was 0.0817%.

  3. Optimum Conditions for Uricase Enzyme Production by Gliomastix gueg

    Directory of Open Access Journals (Sweden)

    Atalla, M. M.

    2009-01-01

    Full Text Available Nineteen strains of microorganisms were screened for uricase production. Gliomastix gueg was recognized to produce high levels of the enzyme. The optimum fermentation conditions for uricase production by Gliomastix gueg were examined. Results showed that uric acid medium was the most favorable one, the optimum temperature was at 30ºC, and incubation period required for maximum production was 8 days with aeration level at 150 rpm and at pH 8.0. Sucrose proved to be the best carbon source, uric acid was found to be the best nitrogen source. Both, dipotassium hydrogen phosphate and ferrous chloride as well as some vitamins gave the highest amount of uricase by Gliomastix gueg.

  4. Developed Hybrid Model for Propylene Polymerisation at Optimum Reaction Conditions

    Directory of Open Access Journals (Sweden)

    Mohammad Jakir Hossain Khan

    2016-02-01

    Full Text Available A statistical model combined with CFD (computational fluid dynamic method was used to explain the detailed phenomena of the process parameters, and a series of experiments were carried out for propylene polymerisation by varying the feed gas composition, reaction initiation temperature, and system pressure, in a fluidised bed catalytic reactor. The propylene polymerisation rate per pass was considered the response to the analysis. Response surface methodology (RSM, with a full factorial central composite experimental design, was applied to develop the model. In this study, analysis of variance (ANOVA indicated an acceptable value for the coefficient of determination and a suitable estimation of a second-order regression model. For better justification, results were also described through a three-dimensional (3D response surface and a related two-dimensional (2D contour plot. These 3D and 2D response analyses provided significant and easy to understand findings on the effect of all the considered process variables on expected findings. To diagnose the model adequacy, the mathematical relationship between the process variables and the extent of polymer conversion was established through the combination of CFD with statistical tools. All the tests showed that the model is an excellent fit with the experimental validation. The maximum extent of polymer conversion per pass was 5.98% at the set time period and with consistent catalyst and co-catalyst feed rates. The optimum conditions for maximum polymerisation was found at reaction temperature (RT 75 °C, system pressure (SP 25 bar, and 75% monomer concentration (MC. The hydrogen percentage was kept fixed at all times. The coefficient of correlation for reaction temperature, system pressure, and monomer concentration ratio, was found to be 0.932. Thus, the experimental results and model predicted values were a reliable fit at optimum process conditions. Detailed and adaptable CFD results were capable

  5. Optimum conditions for enzymatic degradation of some oilseed proteins

    Directory of Open Access Journals (Sweden)

    El-Zanaty, E. A.

    2002-09-01

    Full Text Available Soybean, sesame seed, and rice bran meal proteins were hydrolyzed with two enzymes, namely, papain and bromelain. Experiments were carried out to elucidate the optimum condition for each enzyme when acting on each substrate seperately. Results revealed that the highest relative activities for papain were achieved with E/S 0.06 , 0.29, 0.19 and pH 7.2, 7.0, 7.0 for soybean, sesame,and rice bran meal proteins, respectively. Optimum temperature for papain while hydrolysing the three substrates was 50 ºC. When using bromelain optimum E/S resulting in highest relative activities were 0.067, 0.058 and 0.21 for soybean, sesame,and rice bran meal protein, respectively. Optimum pH was 6.0 and optimum temperature was 45 ºC for bromelain when hydrolysing the protein of the three substrates. A numerical correlation of enzymatic behaviour for the different substrates was calculated.Proteínas de haba de soja, semilla de sésamo y harina de germen de arroz se hidrolizaron con dos enzimas, denominadas, papaina y bromelaina. Se han llevado a cabo experimentos para determinar las condiciones óptimas de cada enzima cuando actúan separadamente sobre cada sustrato. Los resultados mostraron que las mayores actividades relativas para la papaina se consiguieron con una E/S 0,06, 0,29, 0,19 y un pH 7.2, 7.0, 7.0 para las proteínas de haba de soja, sésamo y harina de germen de arroz, respectivamente. La temperatura óptima para la papaina durante la hidrólisis de los tres sustratos fue de 50 ºC. Cuando se usa bromelaina las relaciones E/S óptimas que proporcionaron mayor actividad relativa fueron 0.067, 0.058 y 0.21 para las proteínas de habas de soja, sésamo y harina de germen de arroz respectivamente. El pH óptimo fue 6.0 y la temperatura óptima 45 ºC para la bromelaina cuando se hidroliza la proteína de los tres sustratos. Con estos datos se hizo una correlación numérica del comportamiento enzimático para los diferentes sustratos.

  6. Optimum operating regimes for the ideal wind turbine

    DEFF Research Database (Denmark)

    Okulov, Valery; Sørensen, Jens Nørkær

    2007-01-01

    We here present new results on the classical work of the optimum rotor. The emphasis is put vortex theory for which we have developed a new analytical method to determine the loading on an optimum win turbine rotor. The introduction of the work is a repetition of results using momentum theory...

  7. Optimum conditions for prebiotic evolution in extraterrestrial environments

    Science.gov (United States)

    Abbas, Ousama H.

    The overall goal of the dissertation was to devise synthetic pathways leading to the production of peptides and amino acids from smaller organic precursors. To this end, eight different zeolites were tested in order to determine their catalytic potential in the conversion of amino acids to peptides. The zeolites tested were either synthetic or naturally occurring. Acidic solutions of amino acids were prepared with or without zeolites and their reactivity was monitored over a four-week time interval. The kinetics and feasibility of peptide synthesis from selected amino acid combinations was investigated via the paper chromatography technique. Nine different amino acids were tested. The nature and extent of product were measured at constant time intervals. It was found that two ZSM-5 synthetic zeolites as well as the Fisher Scientific zeolite mix without alumina salts may have a catalytic potential in the conversion of amino acids to peptides. The conversion was verified by matching the paper chromatogram of the experimental product with that of a known peptide. The experimental results demonstrate that the optimum solvent system for paper chromatographic analysis of the zeolite-catalyzed self-assembly of the amino acids L-aspartic acid, L- asparagine, L-histidine, and L-serine is a 50:50 mixture of 1-butanol and acetone by volume. For the amino acids L-alanine, L-glycine, and L-valine, the optimum solvent was found to be a 30:70 mixture of ammonia and propanol by volume. A mathematical model describing the distance traveled (spot position) versus reaction time was constructed for the zeolite-catalyzed conversion of L- leucine and L-tyrosine and was found to approximately follow the function f(t) = 25 ln t. Two case studies for prebiotic synthesis leading to the production of amino acids or peptides in extraterrestrial environments were discussed: one involving Saturn's moon Titan, and the other involving Jupiter's moon Europa. In the Titan study, it was determined

  8. Optimum reliable operation of water distribution networks by ...

    African Journals Online (AJOL)

    2015-01-07

    Jan 7, 2015 ... regard, the system operation costs, including energy and disinfection chemicals, as well as system ..... The network layout (Anytown (Murphy et al., 1994)). ܲܧܰ ൌ .... FOR STRATEGIC PLANNING AND SUPERVISION) (2013).

  9. Research on Optimum Operation and Structure of Tundish

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Much researches on the operation and structure of tundish were carried out at Xiangtan Iron and Steel Co Ltd to increase the yield of grade 20 carbon steel on the continuous casting production line. Through analyzing formation mechanism of pinholes and non-metallic inclusions in billets and describing pattern of the flow of molten steel in tundish by a mathematic model, it was shown that the structure and operation of tundishes play an important part in product quality. So some measures were taken as follows: (1) Optimizing the tundish construction to decrease the impact of liquid steel and lengthening the residence time of liquid steel for homogenization of liquid steel; (2) Improving the influent and effluent operation of liquid steel to avoid the contact of liquid steel with air in order to decrease reoxidation; (3) Reducing over heat during continuous casting. After above measures being taken, the yield of grade 20 carbon steel and the service life of equipment were improved remarkably.

  10. Numerical simulation of flow phenomena and optimum operation of tundish

    Institute of Scientific and Technical Information of China (English)

    时章明; 鄂加强; 刘春洋; 梅炽; 张全; 周应其

    2003-01-01

    To enhance the quality of grade 20 carbon-steel on the continuous casting production line, the mechanism of forming blowholes and non-metallic inclusions in billets and numerical simulation of flow phenomena about liquid steel in tundish were studied. The results show that the configuration and operation of tundish play an important part in quality assurance of grade 20 carbon-steel products. By optimizing the configuration of the tundish, the depth of liquid bath in tundish is enhanced, the impact of liquid steel is decreased, and the residence time of liquid steel is lengthened, which is useful for eliminating inclusions and blowholes and improving the service life of tundish. Improving the pouring and tapping operation of liquid steel can avoid the contact of liquid steel with air, and decrease re-oxidation. Strict control of the superheat degree of casting liquid steel can decrease the non-metallic inclusion content of the re-oxidation in billets and reduce the erosion of tundish. The inclusions and blowholes in the continuous casting grade 20 steel billets are reduced to a great extent and qualification rate is enhanced from 60 % to 80 %.

  11. Performance of a slurry bubble column reactor for Fischer-Tropsch synthesis: Determination of optimum condition

    Energy Technology Data Exchange (ETDEWEB)

    Woo, Kwang-Jae; Kang, Suk-Hwan; Kim, Seung-Moon; Bae, Jong-Wook; Jun, Ki-Won [Advanced Chemical Technology Division, Korea Research Institute of Chemical Technology (KRICT), P.O. Box 107, Yuseong, Daejeon 305-600 (Korea)

    2010-04-15

    The CO conversion and selectivity to C{sub 1}+ and C{sub 11}+ wax products over Co/Al{sub 2}O{sub 3} as well as Ru/Co/Al{sub 2}O{sub 3} Fischer-Tropsch (F-T)catalysts were investigated by varying reaction temperature (210-250 C), system pressure (1.0-3.0 MPa), GHSV (1000-6000 L/kg/h), superficial gas velocity (1.7-13.6 cm/s) and slurry concentration (9.09-26.67 wt.%) in a slurry bubble column reactor (0.05 m diameter x 1.5 m height) to determine the optimum operating conditions. Squalane or paraffin wax was used as initial liquid media. The overall CO conversion increased with increasing reaction temperature, system pressure and catalyst concentration. However, the local maximum CO conversion was exhibited at GHSV of 1500-2000 L/kg/h and superficial gas velocity of 3.4-5.0 cm/s. The CO conversion in the case of Ru/Co/Al{sub 2}O{sub 3} was much higher and stable than that in the case of Co/Al{sub 2}O{sub 3}. The selectivity to C{sub 11}+ wax products increased slightly with increasing GHSV; on the other hand, it decreased with increasing reaction temperature, system pressure, and solid concentration in a slurry bubble column reactor. It could be concluded that the optimum operating conditions based on the yield of hydrocarbons and wax products were; U{sub G} 6.8-10 cm/s, Cs = 15 wt.%, T = 220-230 C, P = 2.0 MPa in a slurry bubble column reactor for F-T synthesis. (author)

  12. DETERMINATION of OPTIMUM CONDITION of PAPAIN ENZYME FROM PAPAYA VAR JAVA (Carica papaya

    Directory of Open Access Journals (Sweden)

    Aline Puspita Kusumadjaja

    2010-06-01

    Full Text Available A study to investigate the optimum condition of papain enzyme has been carried out. The condition that are investigated are pH and temperature, based on measurement of enzyme activity which is defined as mmole tyrosin that are released in reaction between papain enzyme and casein as substrat per minute. In this research, the papain enzyme was isolated from pepaya burung varietas Java. The enzyme was partially purified by precipitation method using 30% - 50% saturated acetone. The result showed that the optimum conditions of papain enzyme are in pH 6 with activity 2,606 U/mL, and temperature at 50 oC with activity 2,469 U/mL. Keywords : Papaya var Java, papain, optimum condition, enzymatic activity

  13. Exploring the optimum conditions for maximizing the microbial growth of Candida intermedia by response surface methodology.

    Science.gov (United States)

    Yönten, Vahap; Aktaş, Nahit

    2014-01-01

    Exploring optimum and cost-efficient medium composition for microbial growth of Candida intermedia Y-1981 yeast culture growing on whey was studied by applying a multistep response surface methodology. In the first step, Plackett-Burman (PB) design was utilized to determine the most significant fermentation medium factors on microbial growth. The medium temperature, sodium chloride and lactose concentrations were determined as the most important factors. Subsequently, the optimum combinations of the selected factors were explored by steepest ascent (SA) and central composite design (CCD). The optimum values for lactose and sodium chloride concentrations and medium temperature were found to be 18.4 g/L, 0.161 g/L, and 32.4°C, respectively. Experiments carried out at the optimum conditions revealed a maximum specific growth rate of 0.090 1/hr; 42% of total lactose removal was achieved in 24 h of fermentation time. The obtained results were finally verified with batch reactor experiments carried out under the optimum conditions evaluated.

  14. Operant Conditioning for Special Educators.

    Science.gov (United States)

    Pedrini, Bonnie C.; Pedrini, D. T.

    The paper briefly explains operant conditioning as it pertains to special educators. Operant conditioning is thought to be an efficient method for modifying student behavior. Using the B. F. Skinner frame of reference, operant conditioning is said to include behavior modification and therapy, programed instruction, and computer assisted and…

  15. Optimum condition-based maintenance policies for deteriorating systems with partial information

    NARCIS (Netherlands)

    Hontelez, J.A.M.; Burger, H.H.; Wijnmalen, D.J.D.

    1996-01-01

    Systems are considered which deteriorate as time goes on and whose conditions can be observed. The optimum maintenance policy with respect to cost is determined, based on a continuous deterioration process, by formulating the decision process as a discrete Markov decision problem. Examples from the

  16. Development of optimum conditions for modification of Kpautagi clay for application in petroleum refinery wastewater treatment

    Directory of Open Access Journals (Sweden)

    Matthew A. ONU

    2015-12-01

    Full Text Available Kautagi clay is a kaolin type deposit that is abundantly available in Niger State, Nigeria with potential for application in pollution control such as wastewater treatment. This study investigates the optimum conditions for modification of Kpautagi clay for application in refinery wastewater treatment. Sulphuric acid was used in the modification of the clay and the modification variables considered were acid concentration, activation time and temperature. To develop the optimum conditions for the modification variables, the sulphuric acid modified Kpautagi clay was applied in the treatment of refinery wastewater in column mode at a fixed flow rate and mass of adsorbent. The results obtained indicate that the optimum conditions for modification of Kpautagi clay for application in the treatment of petroleum refinery wastewater are: acid concentration of 4M; activation time of 120min and activation temperature of 100°C. Therefore, the optimum conditions developed in this study for modification of Kpautagi clay could be applied for improved performance in the treatment of petroleum refinery wastewater.

  17. Determining the optimum process parameter for grinding operations using robust process

    Energy Technology Data Exchange (ETDEWEB)

    Neseli, Suley Man; Asilturk, Ilhan; Celik, Levent [Univ. of Selcuk, Konya (Turkmenistan)

    2012-11-15

    We applied combined response surface methodology (RSM) and Taguchi methodology (TM) to determine optimum parameters for minimum surface roughness (Ra) and vibration (Vb) in external cylindrical grinding. First, an experiment was conducted in a CNC cylindrical grinding machine. The TM using L{sup 27} orthogonal array was applied to the design of the experiment. The three input parameters were workpiece revolution, feed rate and depth of cut; the outputs were vibrations and surface roughness. Second, to minimize wheel vibration and surface roughness, two optimized models were developed using computer aided single objective optimization. The experimental and statistical results revealed that the most significant grinding parameter for surface roughness and vibration is workpiece revolution followed by the depth of cut. The predicted values and measured values were fairly close, which indicates 2 ( 94.99 R{sup 2Ra}=and 2 92.73) R{sup 2Vb}=that the developed models can be effectively used to predict surface roughness and vibration in the grinding. The established model for determination of optimal operating conditions shows that a hybrid approach can lead to success of a robust process.

  18. DETERMINATION of OPTIMUM CONDITION of PAPAIN ENZYME FROM PAPAYA VAR JAVA (Carica papaya )

    OpenAIRE

    Kusumadjaja, Aline Puspita; Dewi, Rita Puspa

    2010-01-01

    A study to investigate the optimum condition of papain enzyme has been carried out. The condition that are investigated are pH and temperature, based on measurement of enzyme activity which is defined as mmole tyrosin that are released in reaction between papain enzyme and casein as substrat per minute. In this research, the papain enzyme was isolated from pepaya burung varietas Java. The enzyme was partially purified by precipitation method using 30% - 50% saturated acetone. The result showe...

  19. Optimum condition of anisotropic plasma etching for improving bending properties of ionic polymer-metal composites.

    Science.gov (United States)

    Choi, N J; Lee, H K; Jung, S; Park, K H

    2010-05-01

    We presented an anisotropic plasma etching technique by reactive ion etcher (RIE) as a new pretreatment method of fabrication of ionic polymer-metal composite (IPMC). We already found that the new technique provided large displacement to the fabricated IPMC in the presence of low applied voltage. However, we did not examine the optimum condition for the anisotropic plasma etching. In this research, we tried to figure out optimum treatment condition of film in etcher. Nafion (by DuPont) films were etched using various etching time and shadow masks with various slit and space sizes. The etched samples were plated with Pt at top and bottom side by Oguro's reduction method. The surface morphology of fabricated IPMCs was characterized by SEM. And, we've measured surface resistance, bending displacement, and driving force in order to check the IPMC properties out. Here, we found that optimum condition for pre-treatment of Nafion was 1 min for etching time under shadow mask with 200 microm slit and 100 microm space.

  20. Batch process. Optimum designing and operation of a batch process; Bacchi purosesu

    Energy Technology Data Exchange (ETDEWEB)

    Hasebe, S. [Kyoto Univ. (Japan). Faculty of Engineering

    1997-09-05

    Since the control of a batch process becomes dynamic, it becomes necessary to handle the process differently from a continuous process in terms of the designing, operating and controlling of the process. This paper describes the characteristics and the problems to be solved of a batch process from three points of view, the designing, operation and controlling of the process. A major problem of a batch process is the designing difficulty. In a batch process, the amount of products capable of being manufactured per unit time by each apparatus and that by the whole plant structured by combining apparatuses are different, and therefore the time and apparatus capacity are wasted in some cases. The actual designing of a batch process involves various factors, such as the seasonal fluctuation of demand for products, the possibility of expanding the apparatuses in the future and the easiness of controlling the process, and the shipment of products during consecutive holidays and periodic maintenance, which are not included in the formulation of mathematical programming problems. Regarding the optimum operation of a batch process and the controlling of the same, descriptions of forming of a dynamic optimum operation pattern and verification of the sequence control system are given. 9 refs., 4 figs.

  1. Analytical study of the Optimum Operation Strategy for an Hybrid-SIT in SBO

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, In Seop; Kang, Hyun Gook [KAIST, Daejeon (Korea, Republic of)

    2015-10-15

    Passive auxiliary feedwater system (PAFS) is the primary system which will be used in residual heat removal. Since the PAFS relies on the natural circulation in primary coolant system and steam condensation in water tank, it is designed to be operated even in a SBO accident. If both PAFSs fail, depressurization of the RCS is necessary for low-pressure injection by normal SITs. This strategy however causes loss of RCS inventory which may cause limited natural circulation in the primary coolant system when the PAFSs are restored. In that sense, if RCS inventory can be maintained during core cool down by high-pressure injection, it increases the diversity of mitigation means. In order to develop this operation strategy, five main factors were identified: the number of PAFSs in simultaneous operation before PCCT refill failure, the number of H-SITs in simultaneous operation, and the overlap percentage, initiation timing, and operation order of the H-SITs. Based on these main factors, the optimum values were identified by analytical and theoretical studies. Results demonstrated that the H-SITs should initiate when the upper plenum level is 0%, and should operate in a 4-3-2-1 order. In case of overlap percentage, it varies according to the number of PAFSs in operation for 8 hours. With both PAFSs in operation before H-SIT initiation, the optimum overlap percent was found to be 31%, with a value of 34% for one PAFS in operation before H-SIT initiation. The results of these two cases are not much different as the decay heat generation rate in both cases is similar. When both PAFSs fail to operate, the result of analytical study demonstrated the H-SITs should overlap by 74%, as the decay heat generation rate during H-SIT operation was very high compared to the other cases. In this case, with dual overlap of the H-SITs in simultaneous operation, a 4.6% overlap is sufficient to mitigate the accident.

  2. Effect of Alcohol Structure on the Optimum Condition for Novozym 435-Catalyzed Synthesis of Adipate Esters

    Directory of Open Access Journals (Sweden)

    Mohd Basyaruddin Abdul Rahman

    2011-01-01

    Full Text Available Immobilized Candida antarctica lipase B, Novozym 435, was used as the biocatalyst in the esterification of adipic acid with four different isomers of butanol (n-butanol, sec-butanol, iso-butanol, and tert-butanol. Optimum conditions for the synthesis of adipate esters were obtained using response surface methodology approach with a four-factor-five-level central composite design concerning important reaction parameters which include time, temperature, substrate molar ratio, and amount of enzyme. Reactions under optimized conditions has yielded a high percentage of esterification (>96% for n-butanol, iso-butanol, and sec-butanol, indicating that extent of esterification is independent of the alcohol structure for primary and secondary alcohols at the optimum conditions. Minimum reaction time (135 min for achieving maximum ester yield was obtained for iso-butanol. The required time for attaining maximum yield and also the initial rates in the synthesis of di-n-butyl and di-sec-butyl adipate were nearly the same. Immobilized Candida antarctica lipase B was also capable of esterifying tert-butanol with a maximum yield of 39.1%. The enzyme is highly efficient biocatalyst for the synthesis of adipate esters by offering a simple production process and a high esterification yield.

  3. Paranormal weighted conditional type operators

    OpenAIRE

    Estaremi, Yousef

    2014-01-01

    In this paper, some sub-classes of paranormal weighted conditional expectation type operators, such as *-paranormal, quasi-*-paranormal and (n; k)-quasi-*-paranormal weighted conditional expectation type opera- tors on $L^2(\\Sigma)$ are investigated. Also, some applications about the spectrum, point spectrum, joint point spectrum, approximate point spectrum and joint approximate point spectrum of these classes are presented.

  4. Optimum condition of spot size and spacing in particle scanning irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Hye Jeong [Dept. of Particle Accelerator and Medical Physics, Dong A University, Busan (Korea, Republic of); Yoo, Seung Hoon; Cho, Il Sung; Song, Yong eun; Shin, Jae Ik; Kim, Eun Ho; Jung, Won Gyun [Div. of Heavy Ion Clinical Research, Korea Institute of Radiological and Medical Science, Seoul (Korea, Republic of)

    2015-10-15

    In our study, spot size, lateral spot spacing and longitudinal layer intervals were investigated to find optimum conditions for planning quality. Broad beam irradiation was used for the treatment, however, IMPT using scanning irradiation is very important for the reducing OAR dose. In the case of the scanning irradiation, there are many scanning parameters. Spot size, lateral spot spacing and longitudinal layer spacing (layer interval) are very important scanning conditions which affect the planning quality and treatment time. In most of treatment sites using proton scanning irradiation system, the spot size depends on the beam energy and spot spacing was used in 2-4 mm fixed. These conditions are applied all kinds of patients. However, optimized scanning conditions are very important for more efficient treatment of the patients which have individual specific features including PTV volume, irregularity of the target. As spot size decreases, the planning quality of the PTV and OAR became significantly better for skull base compared to the prostate case.

  5. Determination of Optimum Frame Rates for Observation of Construction Operations from Time-Lapse Movies

    Directory of Open Access Journals (Sweden)

    Y. M. Ibrahim

    2012-07-01

    Full Text Available Construction professionals have been using time-lapse movies in monitoring construction operations. However, some amount of detail is always lost in the interval between two consecutive frames in a time-lapse movie. This poses the question: By how much can the frame rate be lowered from the standard 30fps (frames per second to allow for the accurate observation of construction operations from a time-lapse movie? This paper addresses the problem by establishing the optimum frame rates for observation of activities related to mortar mixing and block handling. The activities were first recorded at the standard rate of 30fps. Using the Adobe Premier Pro video editing software, the records were then segregated into still images from which 15 different time-lapse movies of various time intervals were generated. The movies were then shown to 25 Construction Managers. A structured questionnaire was employed to capture the level of accuracy with which Construction Managers could interpret the job site situation from each movie. The results suggest that 1fpm (frame per minute is sufficient for the accurate tracking of labourers involved in mortar mixing while 1 frame in every 20 seconds is sufficient for accurate identification of number of cement bags used. However, for tracking number of blocks off-loaded, and those damaged, 1 frame in every 2 seconds is required.

  6. Algorithms of Optimum Slurry Selection for Soil and Rock Sealing Operations

    Directory of Open Access Journals (Sweden)

    Stryczek Stanis³aw

    2004-09-01

    Full Text Available Technical problems, usually caused by complex geological and hydrogeological conditions, are often encountered in mining, drilling and geoengineering operations, as well as in hydrotechnical and underground construction.Natural hazards in the above engineering operations are frequently liquidated by reinforcement and sealing of the ground with the use of injection methods with pre-selected sealing slurries.The authors present methods for slurry technological parameters normalization, depending on the scope and target of sealing operations, and algorithm of slurry selection of soil and rock sealing.

  7. WORK CONDITIONS OF CHAINSAW OPERATORS

    Directory of Open Access Journals (Sweden)

    Jorge Roberto Malinovski

    2002-01-01

    Full Text Available The objective of this research was to analyze the human factors and the work conditions in clear-cutting operations using chainsaws in mountainous areas. Data were colected in a forestry company in Minas Gerais, Brazil, by interviews with 29 chainsaw operators. The results indicated that the operators average age was 32.3 years, height 1.68m and body weight 64.4Kg. The average job time in the company was 112 months and the average time of chainsaw operation experience was 81.5 months. Most (93.1% were dexterous and 6.9% were left-handed. The high incidence of backache (41.4% indicated that the task demands an overload of lumbar column, so that the company should take preventive measures to avoid backaches, using educational strategies or changing the opera-tional system. The high level of accidents (44.8% indicated that some precautions are needed to im-prove work safety.

  8. Optimum Conditions for the Removal of Cr(VI using Modified Eucalyptus Bark

    Directory of Open Access Journals (Sweden)

    Fenjie Niu

    2014-10-01

    Full Text Available The aims of this study were response surface modeling and optimization of Cr(VI removal from solution using formaldehyde-modified eucalyptus bark. A high removal rate of Cr(VI was achieved under the conditions of low adsorbent dosing quantity and high initial concentration of Cr(VI. Analysis of variance showed a high multiple coefficient of determination (R2=0.9875, adjusted determination coefficient (R2Adj=0.9714, and the good second order regression equation. The initial concentration of Cr(VI was 40.15 mg/L, adsorbent dosing quantity 3.40 g/L, and initial reaction pH 2.78, and the largest removal rate was 99.998% under the optimum reaction conditions. Langmuir and Freundlich isothermal models described well adsorption of Cr(VI by the modified stringy bark. Adsorption kinetics studies showed that the adsorption was controlled by multiple factors, dominated by chemical adsorption. The adsorption was found to be spontaneous and endothermic, with △G0 0, and △S0 > 0. Adsorption of Cr(VI by formaldehyde-modified stringy bark was partly controlled by REDOX reactions. The adsorbents were characterized by SEM and FTIR.

  9. Optimum processing conditions for the fabrication of large, single grain Ag-doped YBCO bulk superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Iida, K. [IRC in Superconductivity and Department of Engineering, University of Cambridge, Cavendish Laboratory 19 JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom)], E-mail: k.iida@ifw-dresden.de; Babu, N.H. [IRC in Superconductivity and Department of Engineering, University of Cambridge, Cavendish Laboratory 19 JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom); BCAST, Brunel University, West London UB8 3PH (United Kingdom); Pathak, S.; Shi, Y.; Yeoh, W.K. [IRC in Superconductivity and Department of Engineering, University of Cambridge, Cavendish Laboratory 19 JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Miyazaki, T. [Shibaura Institute of Technology, 3-7-5 Toyosu, Koto-ku, Tokyo 135-8548 (Japan); SRL-ISTEC, 1-10-13 Shinonome, Koto-ku, Tokyo 135-0062 (Japan); Sakai, N. [SRL-ISTEC, 1-10-13 Shinonome, Koto-ku, Tokyo 135-0062 (Japan); Murakami, M. [Shibaura Institute of Technology, 3-7-5 Toyosu, Koto-ku, Tokyo 135-8548 (Japan); Cardwell, D.A. [IRC in Superconductivity and Department of Engineering, University of Cambridge, Cavendish Laboratory 19 JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom)

    2008-06-15

    A pseudo Time-Temperature-Transformation (TTT) diagram has been constructed for the optimum melt processing conditions for the fabrication of large, single grain Ag-doped Y-Ba-Cu-O (YBCO/Ag) bulk superconductors. The thermal conditions for the formation of homogeneous nuclei have been investigated and the boundary between this region and that for no grain nucleation has been mapped as a function of holding time. YBCO/Ag bulk samples grow typically in the form of single grains when the processing temperature profile lies within the 'no nucleation' region of the pseudo TTT diagram. However, by studying the YBCO/Ag growth process, some samples have been grown in the form of single grains by employing a temperature profile within the homogeneous grain nucleation region of the phase diagram. Such growth may be achieved when the YBCO/Ag phase constitutes the majority of the volume of the pellet before the growth temperature reaches that at the nucleation boundary. A large, single YBCO/Ag grain of diameter 30 mm has been fabricated successfully based on these studies by both cold-seeding and seeded infiltration growth techniques.

  10. Fermentation Process of Cocoa Based on Optimum Condition of Pulp PectinDepolymerization by Endogenous Pectolityc Enzymes

    Directory of Open Access Journals (Sweden)

    G.P. Ganda-Putra

    2010-08-01

    Full Text Available Pulp degradation during cocoa fermentation can be carried out by depolymerization process of pulp pectin using endogenous pectolytic enzymes at optimum condition. The objectives of this research were to study the effect of fermentation process based on optimum condition in terms of temperature and pH of pulp pectin depolymerization using endogenous pectolytic enzymes polygalakturonase (PG and pectin metyl esterase (PME and fermentation period in cocoa processing on quality characteristics of cocoa beans produced and to study the role of those fermentation process in reducing fermentation time to produce cocoa beans with standard quality. This research used split plot design, with treatments of process condition of cocoa fermentation as main plot and fermentation period as split plot. Treatment of process condition of cocoa fermentation consisted of optimum condition for pulp pectin depolymerization by PGs (temperature 47.5OC; initial pulp pH 4.6; optimum condition of depolymerization on sequence depolymerization by PGs (temperature 48.5OC; initial pulp pH 8.0 during 1 day; last temperature 47.5OC; initial pulp pH 4.6 during 6 days, and natural fermentation process a control. While treatment of fermentation period consisted of 0, 1, 2, 3, 4, 5, 6 and 7 days. Evaluation of fermentation period was carried out based on pursuant to criteria of unfermented beans content and fermentation index. The results showed that process condition and fermentation time of cocoa affected quality characteristic of cocoa beans produced. Period of cocoa fermentation process based on optimum condition for pulp pectin depolymerization using endogenous pectolytic enzymes was 2 days shorter compared to natural fermentation. Cocoa beans quality of grade I and II were obtained from fermentation time of 4 and 2 days, respectively, using fermentation process based on optimum condition of pulp pectin depolymerization using endogenous pectolytic enzymes, whereas 6 and 4 days

  11. Biological identification and determination of optimum growth conditions for four species ofNavicula

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xiaobo; PANG Shaojun; LIU Feng; SHAN Tifeng; LI Jing

    2014-01-01

    Four species in the genus Navicula were isolated using the serial dilution method. Based on scanning elec-tron microscopy (SEM) and sequence comparisons of two segments of genes (small ribosomal subunit and large subunit of Rubisco), the species were identified asNavicula perminuta,N. pseudacceptata,N. vara, andN. rhynchocephala. Based on phylogenetic analysis and culture trials,there was a close relationship betweenN. perminutaandN. vara. Growth of these species was evaluated using measurements of optical density at 680 nm (OD680) under various environmental factors. Results showed that the optimum culture conditions were 25°C, 50-100 μmol photons m-2 s-1, pH 8.0, and salinities from 25 to 30. However, the favor-able salinity forN. perminuta was surprisingly high at 35. Nutrient requirement analysis demonstrated that growth ofNavicula depended on the availability of SiO32-. Their relative growth rates (RGR) peaked at the highest tested level (0.25 mmol/L). The optimal concentrations of NO3-and PO43- were 3.6 mmol/L and 0.18 mmol/L, respectively. Culture of theseNavicula species for abalone or sea cucumber aquaculture should take these factors into consideration.

  12. Optimum condition by mechanical characteristic evaluation in friction stir welding for 5083-O Al alloy

    Institute of Scientific and Technical Information of China (English)

    Min-Su HAN; Seung-Jun LEE; Jae-Cheul PARK; Seok-Cheol KO; Yong-Bin WOO; Seong-Jong KIM

    2009-01-01

    The mechanical characteristics for friction stir welding (FSW) of 5083-O Al alloy were evaluated. The results show that in FSW at 800 r/min and 124 mm/min, a weld defect is observed at the start point. However, the button shape at the end point is good and the stir zone has a soft appearance. At 267 mm/min, a void occurs at the button. A slight weld defect and rough stir zone are seen both at the start and end points at 342 mm/min. Moreover, at the bottom, a tunnel-type void is observed from an early stage to the end point, and at 1 800 r/min, a weld defect can be found from an early stage to the end point. These defects are rough with imperfect joining due to excessive rotation speed and high physical force. Weld fractures relative to rotational and travel speeds are observed at the stir zone. The optimum FSW conditions are a welding speed of 124 mm/min and a rotational speed of 800 r/min.

  13. Effect of process parameters on optimum welding condition of DP590 steel by friction stir welding

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Gon; Kim, Ji Sun; Kim, In Ju [Korea Institute of Industrial Technology, Gwangju (Korea, Republic of)

    2014-12-15

    In the automotive industry, vehicle weight reduction techniques have been actively studied to improve the rate of fuel consumption and to cope with the regulation restricting exhaust gas. For this reason, advanced high-strength steel (AHSS) is preferred in the automobile industry as its tensile strength is 590 MPa and over. In this study, to obtain the optimum welding condition, the friction stir welding (FSW) process applied to AHSS was considered. The FSW experiment was performed on a stir plate using a Si{sub 3}N{sub 4} tool and a 1.4-mm thick DP590 steel sheet manufactured by cold rolling. In addition, to investigate the temperature distribution of the advancing and retreating sides in the welding state, the tool rotation speed of 800 rpm, and the welding speed of 180 mm/min, a K-type thermocouple was inserted in the backing plate, and the peak temperature was evaluated at each point. Especially, the correlation between the heat input per unit length and the formation of the FSW zone was minutely analyzed.

  14. Dexmedetomidine provides optimum conditions during awake fiberoptic intubation in simulated cervical spine injury patients

    Directory of Open Access Journals (Sweden)

    Pooja Chopra

    2016-01-01

    Conclusions: Dexmedetomidine provides optimum sedation without compromising airway or hemodynamic instability with better patient tolerance and satisfaction for AFOI. It also preserves patient arousability for the postintubation neurological assessment.

  15. Optimum scratch assay condition to evaluate connective tissue growth factor expression for anti-scar therapy.

    Science.gov (United States)

    Moon, Heekyung; Yong, Hyeyoung; Lee, Ae-Ri Cho

    2012-02-01

    To evaluate a potential anti-scar therapy, we first need to have a reliable in vitro wound model to understand dermal fibroblast response upon cell injury and how cytokine levels are changed upon different wound heal phases. An in vitro wound model with different scratch assay conditions on primary human foreskin fibroblast monolayer cultures was prepared and cytokine levels and growth properties were evaluated with the aim of determining optimum injury conditions and observation time. Morphological characteristics of differently scratched fibroblasts from 0 to 36 h post injury (1 line, 2 lines and 3 lines) were investigated. The expression of connective tissue growth factor, CTGF, which is a key mediator in hyper-tropic scarring, and relative intensity of CTGF as a function of time were determined by western blot and gelatin Zymography. After injury (1 line), CTGF level was increased more than 2-fold within 1 h and continuously increased up to 3-fold at 6 h and was leveled down to reach normal value at 36 h, at which cell migration was complete. In more serious injury (2 lines), higher expression of CTGF was observed. The down regulation of CTGF expression after CTGF siRNA/lipofectamine transfection in control, 1 line and 2 lines scratch conditions were 40%, 75% and 55%, respectively. As a model anti-CTGF based therapy, CTGF siRNA with different ratios of linear polyethyleneimine (PEI) complexes (1:1, 1:5, 1:10, 1:20 and 1:30) were prepared and down-regulation efficacy of CTGF was evaluated with our optimized scratch assay, which is 1 line injury at 6 h post injury observation time. As the cationic linear PEI ratio increased, the down regulation efficacy was increased from 20% (1:20) to 55% (1:30). As CTGF level was increased to the highest at 6 h and leveled down afterwards, CTGF level at 6 h could provide the most sensitive response upon CTGF siRNA transfection. The scratch assay in the present study can be employed as a useful experimental tool to differentiate

  16. Optimum Design and Operation of an HVAC Cooling Tower for Energy and Water Conservation

    Directory of Open Access Journals (Sweden)

    Clemente García Cutillas

    2017-03-01

    Full Text Available The energy consumption increase in the last few years has contributed to developing energy efficiency policies in many countries, the main goal of which is decreasing CO 2 emissions. One of the reasons for this increment has been caused by the use of air conditioning systems due to new comfort standards. In that regard, cooling towers and evaporative condensers are presented as efficient devices that operate with low-level water temperature. Moreover, the energy consumption and the cost of the equipment are lower than other systems like air condensers at the same operation conditions. This work models an air conditioning system in TRNSYS software, the main elements if which are a cooling tower, a water-water chiller and a reference building. The cooling tower model is validated using experimental data in a pilot plant. The main objective is to implement an optimizing control strategy in order to reduce both energy and water consumption. Furthermore a comparison between three typical methods of capacity control is carried out. Additionally, different cooling tower configurations are assessed, involving six drift eliminators and two water distribution systems. Results show the influence of optimizing the control strategy and cooling tower configuration, with a maximum energy savings of 10.8% per story and a reduction of 4.8% in water consumption.

  17. Biomass and leaf-level gas exchange characteristics of three African savanna C4 grass species under optimum growth conditions

    NARCIS (Netherlands)

    Mantlana, K.B.; Veenendaal, E.M.; Arneth, A.; Grispen, V.; Bonyongo, C.M.; Heitkönig, I.M.A.; Lloyd, J.

    2009-01-01

    C4 savanna grass species, Digitaria eriantha, Eragrostis lehmanniana and Panicum repens, were grown under optimum growth conditions with the aim of characterizing their above- and below-ground biomass allocation and the response of their gas exchange to changes in light intensity, CO2 concentration

  18. Evaluation of Artificial Neural Network-Based Temperature Control for Optimum Operation of Building Envelopes

    Directory of Open Access Journals (Sweden)

    Jin Woo Moon

    2014-11-01

    Full Text Available This study aims at developing an indoor temperature control method that could provide comfortable thermal conditions by integrating heating system control and the opening conditions of building envelopes. Artificial neural network (ANN-based temperature control logic was developed for the control of heating systems and openings at the building envelopes in a predictive and adaptive manner. Numerical comparative performance tests for the ANN-based temperature control logic and conventional non-ANN-based counterpart were conducted for single skin enveloped and double skin enveloped buildings after the simulation program was validated by comparing the simulation and the field measurement results. Analysis results revealed that the ANN-based control logic improved the indoor temperature environment with an increased comfortable temperature period and decreased overshoot and undershoot of temperatures outside of the operating range. The proposed logic did not show significant superiority in energy efficiency over the conventional logic. The ANN-based temperature control logic was able to maintain the indoor temperature more comfortably and with more stability within the operating range due to the predictive and adaptive features of ANN models.

  19. Photo Decoloration of Methylene Blue with Ribose under Optimum Conditions by Visible Radiation

    Institute of Scientific and Technical Information of China (English)

    AZMAT, Rafia; UDDIN, Fahim

    2009-01-01

    Photo decoloration of the methylene blue (MB) with reducing sugar, ribose (RH), was investigated on an especially designed optical processor using monochromatic radiation of 661 nm through a red filter. The dye molecule gets ex- cited into triplet transient species (MBT) during flushing with lifetime of 10.1 μs into acetate buffered aqueous alcoholic medium, which later on reduces to protonated leuco dye (MBH). Pbotolysis of the aqueous aicholic medium bose into respective acid while hydrogen abstraction and 2e- reduced the dye (MB) into MBH by following reaction MBr++RCHO→MBH+RCOOH. Influences of different operational parameters suggest the imperative role of acidity, reductant and temperature where positive relations with quantum yield (φ) were established under the opti- mum conditions while elevated concentration of dye resulted in the decrease in the absorption of number of photon consequently, and no change in the φ was observed. A highly solvated transient complex was reported in the reduc- tion of MB and RH through thermodynamics activation parameters. A mechanism of MBT formation and its reduc- tion into MBH has been discussed.

  20. Color removal from textile dyebath effluents in a zeolite fixed bed reactor: determination of optimum process conditions using Taguchi method.

    Science.gov (United States)

    Engin, Ahmet Baki; Ozdemir, Ozgür; Turan, Mustafa; Turan, Abdullah Z

    2008-11-30

    Taguchi method was applied as an experimental design to determine optimum conditions for color removal from textile dyebath house effluents in a zeolite fixed bed reactor. After the parameters were determined to treat real textile wastewater, adsorption experiments were carried out. The breakthrough curves for adsorption studies were constructed under different conditions by plotting the normalized effluent color intensity (C/C(0)) versus time (min) or bed volumes (BV). The chosen experimental parameters and their ranges are: HTAB concentration (C(htab)), 1-7.5 gL(-1); HTAB feeding flowrate (Q(htab)), 0.015-0.075 L min(-1); textile wastewater flowrate (Q(dye)), 0.025-0.050 L min(-1) and zeolite bed height (H(bed)), 25-50 cm, respectively. Mixed orthogonal array L(16) (4(2)x2(2)) for experimental plan and the larger the better response category were selected to determine the optimum conditions. The optimum conditions were found to be as follows: HTAB concentration (C(htab))=1g L(-1), HTAB feeding flowrate (Q(htab))=0.015 L min(-1), textile wastewater flowrate (Q(dye))=0.025 L min(-1) and bed height (H(bed))=50 cm. Under these conditions, the treated wastewater volume reached a maximum while the bed volumes (BV) were about 217. While HTAB concentration, gL(-1) (A); zeolite bed height, cm (D) and wastewater flowrate, L min(-1) (C) were found to be significant parameters, respectively, whereas, HTAB flowrate, L min(-1) (B) was found to be an insignificant parameter.

  1. Color removal from textile dyebath effluents in a zeolite fixed bed reactor: Determination of optimum process conditions using Taguchi method

    Energy Technology Data Exchange (ETDEWEB)

    Engin, Ahmet Baki [Sakarya University, Industrial Engineering Department, 54040 Sakarya (Turkey); Ozdemir, Ozguer [Istanbul Technical University, Environmental Engineering Department, 34469 Istanbul (Turkey); Turan, Mustafa [Istanbul Technical University, Environmental Engineering Department, 34469 Istanbul (Turkey)], E-mail: mturan@ins.itu.edu.tr; Turan, Abdullah Z. [Istanbul Technical University, Chemical and Metallurgical Engineering Department, 34469 Istanbul (Turkey)

    2008-11-30

    Taguchi method was applied as an experimental design to determine optimum conditions for color removal from textile dyebath house effluents in a zeolite fixed bed reactor. After the parameters were determined to treat real textile wastewater, adsorption experiments were carried out. The breakthrough curves for adsorption studies were constructed under different conditions by plotting the normalized effluent color intensity (C/C{sub 0}) versus time (min) or bed volumes (BV). The chosen experimental parameters and their ranges are: HTAB concentration (C{sub htab}), 1-7.5 g L{sup -1}; HTAB feeding flowrate (Q{sub htab}), 0.015-0.075 L min{sup -1}; textile wastewater flowrate (Q{sub dye}), 0.025-0.050 L min{sup -1} and zeolite bed height (H{sub bed}), 25-50 cm, respectively. Mixed orthogonal array L{sub 16} (4{sup 2} x 2{sup 2}) for experimental plan and the larger the better response category were selected to determine the optimum conditions. The optimum conditions were found to be as follows: HTAB concentration (C{sub htab}) = 1 g L{sup -1}, HTAB feeding flowrate (Q{sub htab}) = 0.015 L min{sup -1}, textile wastewater flowrate (Q{sub dye}) = 0.025 L min{sup -1} and bed height (H{sub bed}) = 50 cm. Under these conditions, the treated wastewater volume reached a maximum while the bed volumes (BV) were about 217. While HTAB concentration, g L{sup -1} (A); zeolite bed height, cm (D) and wastewater flowrate, L min{sup -1} (C) were found to be significant parameters, respectively, whereas, HTAB flowrate, L min{sup -1} (B) was found to be an insignificant parameter.

  2. Operation Mode and Optimum Design of China’s Agricultural Modern Logistics System

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Using comparative analysis and logical reasoning methods,in combination with traditional logistics theory and practice,and on the basis of objective demand of modern agricultural development for logistics service,we analyze features of logistics function.Besides,we discuss functional elements and service contents of agricultural modern logistics.In addition,we explore innovation model of agricultural modern logistics and systematized operation of supply chain.Finally,it is concluded that logistics development shall bring into full play all functional elements and achieve high efficient operation of the system through enhanced management measures.

  3. Estimation of optimum operating point for thrust magnetic bearing with solid magnet

    Institute of Scientific and Technical Information of China (English)

    孙首群; 田育民

    2003-01-01

    A carrying capacity-temperature rise analysis model has been established for analysis of the carrying capacity, temperature rise and carrying capacity-temperature rise characteristic of a thrust magnetic bearing with solid magnet. The results indicate that there must be an optimal operating point for the thrust magnetic beating with solid magnet. The main factors having effect on carrying capacity-temperature rise include static gap and/or ampere-turns. With proper static gap chosen, the bearing can be run near the optimal operating point by adjhusting ampere-turns, thereby optimizing the bearing properties.

  4. Enhancing Uranium Uptake by Amidoxime Adsorbent in Seawater: An investigation for optimum alkaline conditioning parameters

    Energy Technology Data Exchange (ETDEWEB)

    Das, S.; Tsouris, Constantinos; Zhang, C.; Kim, J.; Brown, S.; Oyola, Yatsandra; Janke, C.; Mayes, R. T.; Kuo, Li-Jung; Wood, Jordana R.; Gill, Gary A.; Dai, Sheng

    2016-04-20

    A high-surface-area polyethylene-fiber adsorbent (AF160-2) has been developed at the Oak Ridge National Laboratory (ORNL) by radiation-induced graft polymerization of acrylonitrile and itaconic acid. The grafted nitriles were converted to amidoxime groups by treating with hydroxylamine. The amidoximated adsorbents were then conditioned with potassium hydroxide (KOH) by varying different reaction parameters such as KOH concentration (0.2, 0.44, and 0.6 M), duration (1, 2, and 3 h), and temperature (60, 70, and 80 ºC). Adsorbent screening was then performed with simulated seawater solutions containing sodium chloride and sodium bicarbonate, at concentrations found in seawater, and uranium nitrate at a uranium concentration of ~ 7-8 ppm and pH 8. FTIR and solid state NMR indicated that a fraction of amidoxime groups was hydrolyzed to carboxylate during KOH conditioning. The uranium adsorption capacity in the simulated seawater screening solution gradually increased with conditioning time and temperature for all KOH concentrations. It was also observed that the adsorption capacity increased with an increase in concentration of KOH for all the conditioning times and temperatures. AF160-2 adsorbent samples were also tested with natural seawater using flow-through experiments to determine uranium adsorption capacity with varying KOH conditioning time and temperature. Based on uranium loading capacity values of several AF160-2 samples, it was observed that changing KOH conditioning time from 3 to 1 h at 60, 70, and 80 ºC resulted in increase of the uranium loading capacity in seawater, which did not follow the trend found in laboratory screening with stimulated solutions. Longer KOH conditioning times lead to significantly higher uptake of divalent metal ions, such as calcium and magnesium, which is a result of amidoxime conversion into less selective carboxylate. Scanning electron microscopy showed that long conditioning times may also lead to adsorbent degradation

  5. Operation Mode and Optimum Design of China's Agricultural Modern Logistics System

    OpenAIRE

    Qin, Shi-bo

    2012-01-01

    Using comparative analysis and logical reasoning methods, in combination with traditional logistics theory and practice, and on the basis of objective demand of modern agricultural development for logistics service, we analyze features of logistics function. Besides, we discuss functional elements and service contents of agricultural modern logistics. In addition, we explore innovation model of agricultural modern logistics and systematized operation of supply chain. Finally, it is concluded ...

  6. Optimum conditions for fabricating superhydrophobic surface on copper plates via controlled surface oxidation and dehydration processes

    Science.gov (United States)

    Zhang, Yan; Li, Wen; Ma, Fumin; Yu, Zhanlong; Ruan, Min; Ding, Yigang; Deng, Xiangyi

    2013-09-01

    The superhydrophobic surfaces on copper substrate were fabricated by direct oxidation and dehydration processes, and the reaction and modification conditions were optimized. Firstly, the oxidation conditions including the concentrations of K2S2O8 and NaOH, the oxidation time were studied. It is found that the superhydrophobicity would be better if the copper plates were oxidized in 0.06 M K2S2O8 and 3.0 M NaOH solution at 65 °C for 35 min. Then, the modification conditions including modifier concentration and modification time were investigated. The results showed that 5 wt% lauric acid and 1 h modification time were suitable modification conditions for preparing copper-based superhydrophobic surfaces. The surface fabricated under optimized conditions displayed excellent superhydrophobicity of high water contact angle of 161.1° and a low contact angle hysteresis of 2.5°. The surface microstructure and composition of the superhydrophobic surfaces were also characterized by SEM and FT-IR. It is found that the highly concentrated micro/nanostructured sheets and the low surface energy materials on the surface should be responsible for the high superhydrophobicity.

  7. Optimum conditions for the water extraction of L-theanine from green tea.

    Science.gov (United States)

    Vuong, Quan V; Stathopoulos, Costas E; Golding, John B; Nguyen, Minh H; Roach, Paul D

    2011-09-01

    Theanine is a unique non-protein amino acid found in tea (Camellia sinensis). It contributes to the favourable umami taste of tea and is linked to various beneficial effects in humans. There is an increasing interest in theanine as an important component of tea, as an ingredient for novel functional foods and as a dietary supplement. Therefore, optimal conditions for extracting theanine from tea are required for the accurate quantification of theanine in tea and as an efficient first step for its purification. This study examined the effects of four different extraction conditions on the yield of theanine from green tea using water and applied response surface methodology to further optimise the extraction conditions. The results showed that temperature, extraction time, ratio of water-to-tea and tea particle sizes had significant impacts on the extraction yield of theanine. The optimal conditions for extracting theanine from green tea using water were found to be extraction at 80 °C for 30 min with a water-to-tea ratio of 20:1 mL/g and a tea particle size of 0.5-1 mm. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. The impact of heat exchanger fouling on the optimum operation and maintenance of the Stirling engine

    Energy Technology Data Exchange (ETDEWEB)

    Kuosa, M.; Kaikko, J.; Koskelainen, L. [Lappeenranta University of Technology, Department of Energy and Environmental Technology, P.O. Box 20, FI-53851 Lappeenranta (Finland)

    2007-07-15

    This paper focuses on the effect of heat exchanger fouling on the performance of the Stirling engine in combined heat and power (CHP) application. Fouling results from using biomass fuels and affects the heat exchanger that transfers heat into the engine. This heat exchanger is referred to as the heater. The heat exchanger that recovers heat from the flue gases is also affected by fouling. To determine the performance of the Stirling engine, a commercial Stirling analysis tool is applied together with models that have been developed for the heat transfer in the heater, regenerator and cooler of the engine. The Stirling engine model uses constant temperatures for the heat addition and rejection, with the theory of displacement engine as a basis. The fouling in the heat exchanger is taken into account by using a fouling factor that corresponds with the degradation in the total heat transfer coefficient. The Stirling engine model together with the model for heat exchanger fouling makes it possible to estimate the effect of fouling on the performance of the Stirling engine. A cost model is developed for the engine to translate changes in performance into economy in CHP operation. In the studied application, the Stirling engine is operated by the heat demand. Together with the selected control method, performance and cost models compose a tool for the simulation and optimization of the system. The use of the models to determine the optimal cleaning interval of the heat exchanger surfaces is considered. (author)

  9. Optimum plasma grid bias for a negative hydrogen ion source operation with Cs

    Energy Technology Data Exchange (ETDEWEB)

    Bacal, Marthe, E-mail: marthe.bacal@lpp.polytechnique.fr [UPMC, LPP, Ecole Polytechnique, UMR CNRS 7648, Palaiseau (France); Sasao, Mamiko [R& D Promotion Organization, Doshisha University, Kamigyoku, Kyoto 602-8580 (Japan); Wada, Motoi [School of Science and Engineering, Doshisha University, Kyotonabe, Kyoto 610-0321 (Japan); McAdams, Roy [CCFE, Culham Science Center, Abingdon, Oxfordshire 0X14 3DB (United Kingdom)

    2016-02-15

    The functions of a biased plasma grid of a negative hydrogen (H{sup −}) ion source for both pure volume and Cs seeded operations are reexamined. Proper control of the plasma grid bias in pure volume sources yields: enhancement of the extracted negative ion current, reduction of the co-extracted electron current, flattening of the spatial distribution of plasma potential across the filter magnetic field, change in recycling from hydrogen atomic/molecular ions to atomic/molecular neutrals, and enhanced concentration of H{sup −} ions near the plasma grid. These functions are maintained in the sources seeded with Cs with additional direct emission of negative ions under positive ion and neutral hydrogen bombardment onto the plasma electrode.

  10. A Nexessary Condition about the Optimum Partition on a Finite Set of Samples and Its Application to Clustering Analysis

    Institute of Scientific and Technical Information of China (English)

    叶世伟; 史忠植

    1995-01-01

    This paper presents another necessary condition about the optimum partition on a finite set of samples.From this condition,a corresponding generalized sequential hard k-means (GSHKM) clustering algorithm is built and many well-known clustering algorithms are found to be included in it.Under some assumptions the well-known MacQueen;s SHKM (Sequential Hard K-Means) algorithm,FSCL(Frequency Sensitive Competitive Learning) algorithm and RPCL (Rival Penalized Competitive Learning) algorithm are derived.It is shown that FSCL in fact still belongs to the kind of GSHKM clustering algorithm and is more suitable for producing means of K-partition of sample data,which is illustrated by numerical experiment.Meanwhile,some improvements on these algorithms are also given.

  11. Investigation of optimum roasting conditions to obtain possible health benefit supplement, antioxidants from coffee beans.

    Science.gov (United States)

    Sulaiman, Shaida Fariza; Moon, Joon-Kwan; Shibamoto, Takayuki

    2011-09-01

    In order to investigate the role of roasting conditions in antioxidant formation, methanol and hot water extracts from Robusta coffee beans roasted for various lengths of time and at various temperatures were analyzed for total phenolic acid, chlorogenic acid, and caffeine content, as well as for their antioxidant activities using 1,1-diphenyl-2-picryhydrazyl (DPPH), thiobarbituric acid (TBA), and malonaldehyde/gas chromatography (MA/GC) assays. The amount of total phenolics in methanol extracts decreased linearly over the roasting temperature from 63.51 ± 0.77 mg chlorogenic acid equivalent (CAE)/g coffee beans (roasted at 200°C) to 42.56 ± 0.33 mg CAE/g coffee beans (roasted at 240°C). The total chlorogenic acid content decreased when the roasting time was increased from 78.33 ± 1.41 mg/g (green coffee beans) to 4.31 ± 0.23 mg/g (roasted for 16 min at 250°C). All methanol extracts from roasted coffee beans possessed over 90% antioxidant activities in the DPPH assay. The antioxidant activity of methanol extracts ranged from 41.38 ± 1.77% (roasted at 250°C for 10 min) to 98.20 ± 1.49% (roasted at 230°C for 16 min) as tested by the TBA assay. The antioxidant activity of methanol extracts of green coffee beans and roasted coffee beans ranged from 93.01% (green coffee beans) to 98.62 ± 1.32% (roasted at 250°C for 14 min) in the MA/GC assays. All hot water extracts exhibited moderate pro-oxidant activities in TBA and MA/GC assays. The results indicated that roasting conditions of coffee beans play an important role in the formation of antioxidants in brewed coffee, which can be dietary supplements having beneficial effect to human health.

  12. Condition Monitoring Of Operating Pipelines With Operational Modal Analysis Application

    Directory of Open Access Journals (Sweden)

    Mironov Aleksey

    2015-12-01

    Full Text Available In the petroleum, natural gas and petrochemical industries, great attention is being paid to safety, reliability and maintainability of equipment. There are a number of technologies to monitor, control, and maintain gas, oil, water, and sewer pipelines. The paper focuses on operational modal analysis (OMA application for condition monitoring of operating pipelines. Special focus is on the topicality of OMA for definition of the dynamic features of the pipeline (frequencies and mode shapes in operation. The research was conducted using two operating laboratory models imitated a part of the operating pipeline. The results of finite-element modeling, identification of pipe natural modes and its modification under the influence of virtual failure are discussed. The work considers the results of experimental research of dynamic behavior of the operating pipe models using one of OMA techniques and comparing dynamic properties with the modeled data. The study results demonstrate sensitivity of modal shape parameters to modification of operating pipeline technical state. Two strategies of pipeline repair – with continuously condition-based monitoring with proposed technology and without such monitoring, was discussed. Markov chain reliability models for each strategy were analyzed and reliability improvement factor for proposed technology of monitoring in compare with traditional one was evaluated. It is resumed about ability of operating pipeline condition monitoring by measuring dynamic deformations of the operating pipe and OMA techniques application for dynamic properties extraction.

  13. PRODUCTION OF α-AMYLASE FROM ASPERGILLUS FLAVUS UNDER SOLID STATE FERMENTATION WITH OPTIMUM CONDITIONS

    Directory of Open Access Journals (Sweden)

    Mamatha J

    2012-08-01

    Full Text Available α-amylases are ubiquitous enzymes produced by plants, animals and microbes, where they play a dominant role in carbohydrate metabolism. In spite of the wide distribution of amylases, microbial sources, namely fungal and bacterial amylases, are used for the industrial production due to advantages such as cost effectiveness, consistency, less time and space required for production and ease of process modification and optimization. Filamentous fungi are known to be prolific producers of extracellular proteins; they are widely exploited for the production of different enzymes including a-amylase. SSF is generally defined as the growth of microorganisms on moist solid substrates with negligible free water, which is preferred than SmF because of simple technique, low capital investment, lower levels of catabolite repression, end- product inhibition, low waste water output, better product recovery and high quality production. Different substrates such as wheat bran, mollasses bran, rice bran, maize meal and sugarcane bagasse were used; out of which sugarcane bagasse has been reported to produce promising results. Different carbon and nitrogen supplements were given which increased the yield of the enzyme and optimized the pH as 6.0 and temperature 300C. Thus the maximum production of amylase was observed at optimized conditions, which can be employed in large scale.

  14. Physiological Strategies to Improve the Performance of Spring Maize (Zea mays L. Planted under Early and Optimum Sowing Conditions.

    Directory of Open Access Journals (Sweden)

    Muhammad Amir Bakhtavar

    Full Text Available Low temperature at stand establishment and high temperature at reproductive stage are involved in reduction of grain yield of spring maize. A field study was therefore conducted to evaluate different physiological strategies for improving performance of spring maize under temperature extremes. Seed priming and foliar spray with 3% moringa leaf extract (MLE and 100 mg L-1 kinetin solution alone or in all possible combinations with each other at three growth stages (knee height, tasseling and grain filling stage and hydropriming was compared with control. Seed priming plus foliar spray of MLE and kinetin significantly improved stand establishment especially under early sown crop as indicated by reduced mean emergence time (MET, improved emergence index (EI and final emergence percentage (FEP. Similarly increased chlorophyll contents, crop growth rate, leaf area index, photosynthetic rate, transpiration rate, relative water content and decreased membrane permeability were recorded in both early and optimum sowing conditions in MLE priming plus foliar spray treatment. All these improvements were harvested in the form of increased yield and harvest index compared with control treatment. Overall crop sown at optimum time performed best but exogenous application of MLE through seed priming and foliar spray maximally improved the performance of early sown maize crop which is attributed more likely due to improved stand establishment, chlorophyll and phenolic contents, increased leaf area duration and grain filling period. It can be concluded that seed priming with MLE along with its foliar spray could increase production of maize under temperature extremes.

  15. Physiological Strategies to Improve the Performance of Spring Maize (Zea mays L.) Planted under Early and Optimum Sowing Conditions.

    Science.gov (United States)

    Bakhtavar, Muhammad Amir; Afzal, Irfan; Basra, Shahzad Maqsood Ahmed; Ahmad, Azraf-Ul-Haq; Noor, Mehmood Ali

    2015-01-01

    Low temperature at stand establishment and high temperature at reproductive stage are involved in reduction of grain yield of spring maize. A field study was therefore conducted to evaluate different physiological strategies for improving performance of spring maize under temperature extremes. Seed priming and foliar spray with 3% moringa leaf extract (MLE) and 100 mg L-1 kinetin solution alone or in all possible combinations with each other at three growth stages (knee height, tasseling and grain filling stage) and hydropriming was compared with control. Seed priming plus foliar spray of MLE and kinetin significantly improved stand establishment especially under early sown crop as indicated by reduced mean emergence time (MET), improved emergence index (EI) and final emergence percentage (FEP). Similarly increased chlorophyll contents, crop growth rate, leaf area index, photosynthetic rate, transpiration rate, relative water content and decreased membrane permeability were recorded in both early and optimum sowing conditions in MLE priming plus foliar spray treatment. All these improvements were harvested in the form of increased yield and harvest index compared with control treatment. Overall crop sown at optimum time performed best but exogenous application of MLE through seed priming and foliar spray maximally improved the performance of early sown maize crop which is attributed more likely due to improved stand establishment, chlorophyll and phenolic contents, increased leaf area duration and grain filling period. It can be concluded that seed priming with MLE along with its foliar spray could increase production of maize under temperature extremes.

  16. Evaluation of optimum modes and conditions of contact ultrasonic treatment of wound surface and creation of tools for its implementation

    Directory of Open Access Journals (Sweden)

    V.N. Khmelev

    2015-08-01

    Full Text Available The paper presents results of researches on evaluation of optimum modes and conditions of contact ultrasound influence on wound surface to remove (extract pathological contents (infectant (separation between liquid and solid phases. In order to optimize modes and conditions of process model of converse ultrasonic capillary effect was proposed. It considers capillary-porous system “solid-liquid” as a whole, but takes into account effects and phenomena inside separate capillary. Among effects and influencing factors it should be underlined following factors: change of dielectric constant leading to changes of disjoining pressure and consequently to the origin of converse ultrasonic capillary effect; bending and radial deformation of the capillary; formation of cavitation fog preventing extraction of wound content. The model allows to determine determine extraction rate depending on amplitude of ultrasonic vibrations, area of radiating surface of the waveguide radiator, amount of drainage canals in it and physical properties of wound content. It was obtained, that for the most widely spread in surgical practice types of wound content (viscosity of no more than 110 mPa∙s vibration amplitude of the radiator of the waveguide-tool should not exceed 39…90 μm at the insonification of the nidus of infection and radiating surface of the radiator of the waveguide-tool should contain no less than 12 draining canals per unit area in 20 cm2 . Evaluated optimum modes and conditions let develop and make ultrasonic waveguide-tools for implementation of extraction process. Designed waveguidetools are recommended to use in specialized medical surgery and conservative therapy devices.

  17. Optimum synthesis conditions of nanometric Fe50Ni50 alloy formed by chemical reduction in aqueous solution

    Indian Academy of Sciences (India)

    Marwa A Mohamed; Azza H El-Maghraby; Mona M Abd El-Latif; Hassan A Farag

    2013-10-01

    In the present article, various nanometric Fe50Ni50 alloys were synthesized by chemical reduction of the corresponding metal ions, with hydrazine in an aqueous solution. Process variables of reaction temperature, pH of the hydrazine solution and concentration of metal ions were varied in order to determine the optimum synthesis conditions regarding quality, productivity and cost. It is found that pH of hydrazine solution, at low concentration of metal ions, is the most crucial variable affecting the reaction rate, average crystallite and particle sizes of the synthesized nanometric Fe50Ni50 alloy, followed by the total concentration of metal ions. Thus, increase of pH of hydrazine solution acts as an efficient stabilizer in reducing the particle size. On the contrary, at high concentration of metal ions, the structural characteristics of the nanometric Fe50Ni50 alloy are almost insensitive to reaction temperature and pH of hydrazine solution, but the reduction rate is remarkably sensitive to reaction temperature. Based on these results, it is decided that a reaction temperature of 80 °C, pH of the hydrazine solution of 12.5 and concentration of metal ions of 0.6 M represent the optimum synthesis conditions. The role of pH of hydrazine solution in reducing the alloy’s average particle size as well as efficient stabilizer confirms tremendous effect of synthesis conditions on the alloy structure and therefore, the importance of this study for industrial production of nanometric Fe50Ni50 alloy.

  18. Entanglement Mapping VS. Quantum Conditional Probability Operator

    Science.gov (United States)

    Chruściński, Dariusz; Kossakowski, Andrzej; Matsuoka, Takashi; Ohya, Masanori

    2011-01-01

    The relation between two methods which construct the density operator on composite system is shown. One of them is called an entanglement mapping and another one is called a quantum conditional probability operator. On the base of this relation we discuss the quantum correlation by means of some types of quantum entropy.

  19. Wetter and cooler: pronounced temperate climate conditions in western Anatolia during the Middle Miocene Climatic Optimum

    Science.gov (United States)

    Güner, Tuncay H.; Bouchal, Johannes M.; Köse, Nesibe; Denk, Thomas

    2017-04-01

    During the course of an ongoing palaeobotanical investigation of the lignite mines of the Yataǧan Basin, Muǧla province, Turkey, the fossil leaves of the Eskihisar lignite mine were analysed using the Climate Leaf Analysis Multivariate Program (CLAMP). The investigated fossil leaves derive from the marls and clayey limestones (Sekköy Member) overlying the exploited lignite seam (uppermost Turgut Member). The age of the studied sedimentary rocks is well constrained by vertebrate fossils occuring in the main lignite seam (MN6 → Gomphoterium angustidens Cuvier, 1817; Percrocuta miocenica Pavlov & Thenius, 1965) and at the Yenieskihisar Mammal locality (MN7/8, uppermost Sekköy Member). 719 specimens were measured and assigned to 65 leaf morphotypes. Using this data, CLAMP reconstructed the following climate parameters: mean annual temperature (MAT) 12.58 (+/-1.5)°C, warm month mean temperature (WMMT) 23.72 (+/-2.5)°C, cold month mean temperature (WMMT) 2.29 (+/-2)°C, length of growing season (LGS) 7.52 (+/-0.75) month, mean growing season precipitation (GSP) 130.1 (+/-40) cm, precipitation during the three wettest months (3-WET) 67 (+/-25) cm, precipitation during the three driest months (3-DRY) 20.4 (+/-7.5) cm. The reconstructed parameters are too cool for tropical climates (the 18˚ C winter isotherm being a threshold for tropical climates) and indicate temperate conditions; climates fitting these parameters (Cfb according to the Köppen-Geiger climate classification) can be found today in regions known as "Tertiary relict areas" (e.g. Black sea coast of Northeast Turkey, eastern China, Japan). Based on a substantial amount of rainfall during the three driest months, it is further possible to exclude markedly seasonal climates such as a summer-dry and winter-wet Mediterranean climate and a summer-wet and winter-dry monsoon climate as commonly found along the southern foothills of the Himalayas and in southwestern China. Instead, a fully humid Cf climate is

  20. Determination of optimum working conditions R22 and R404A refrigerant mixtures in heat-pumps using Taguchi method

    Energy Technology Data Exchange (ETDEWEB)

    Comakli, K.; Simsek, F.; Comakli, O.; Sahin, B. [Ataturk University, Mechanical Engineering Department, 25240 Erzurum (Turkey)

    2009-11-15

    In this study, refrigerants R22 and R404A five of their binary mixtures which contain about 0%, 25%, 50%, 75% and 100% mass fractions of R404A were tested. It is investigated experimentally the effects of gas mixture rate, evaporator air inlet temperature (from 24 to 32 C), evaporator air mass flow rate (from 0.58 to 0.74 kg/s), condenser air inlet temperature (from 22 to 34 C) and condenser air mass flow rate (from 0.57 to 0.73 kg/s) on the coefficient of performance (COP) and exergetic efficiency values of vapor compression heat-pump systems. To determine the effect of the chosen parameters on the system and optimum working conditions, an experimental design method suggested by Genichi Taguchi was used. In this study, it was observed that the most effective parameters are found to be the condenser air inlet temperature for COP and exergetic efficiency. (author)

  1. The Presentation of a Two Stages Model for an Optimum Operation of a Hybrid System of Wind-Pumped Storage Power Plant in the Power Market Environment

    Directory of Open Access Journals (Sweden)

    Mehdi Akbarpour

    2012-11-01

    Full Text Available In this study we present a new method in power market environment. One of the weaknesses in the utilization of wind units is severe dependence of output power level on wind. However, considering the high uncertainty in the prediction of wind speed and wind forecast unit production capacity is also having an error. Also, regarding to the uncontrollable generators of this type, it is better to use combined systems for utilization. This study presents a new model based on the a two stage for an optimum operation of a hybrid system of windpumped storage power plant in the power market environment that causes to provide a successful presentation condition in market environments for the producers of wind power. In the suggestive hybrid system of windpumped storage power plant of this study the modeling is done in two stages for the optimum presence in power market environment with the a most possible benefit. At first, the suggestive model is optimized regarding to uncertainty in the prediction of power price and producing the wind power, for presenting the suggestion of power to market, in order to gain the most benefit. At the second stage, the suggestive model is optimized regarding to uncertainty in producing wind power, in order to gain the most benefit and paying the least penalty for unbalancing in market for operation of the system. In this study, the Particle Swarm Optimization algorithm (PSO is used for optimization. At the end of a model example for applying the results of the proposed model will be examined and analyzes the results. Results show that the model is an appropriate method for the operation of this combined system in market environment.

  2. Experimental and numerical investigation of optimum location for FCU in an all-water air conditioning system

    Energy Technology Data Exchange (ETDEWEB)

    Elsafty, A.F.; Hassan, A.A. [Arab Academy for Science and Technology and Marine Transport, Alexandria (Egypt). Dept. of Mechanical and Marine Engineering, College of Engineering and Technology

    2006-07-01

    In this study, an all-water air conditioning (AC) system was used to determine the optimum location of a fan cooling unit inside a room. The AC system consisted of a condensing unit; a storage tank; a fan coil unit; a circulating pump; and a direct digital control unit (DDC). Cooling loads were calculated using a software tool called HVAC Explorer. A series of flow pattern experiments were conducted in order to verify the optimal location of the fan coil. Velocity and temperature contour profiles were used to measure thermal comfort conditions. Two standard k-{epsilon} equation models were used to examine the effect of air flow turbulence. Experimental test results were then compared with computational fluid dynamics (CFD) results for the 3 positions of the fan coil unit inside the room. Values were measured using an air flow meter device. The 3-D geometry of the room model was generated using commercial software and a steady state analysis technique. It was concluded that the model accurately measured the air conditioning system's air flow patterns. 1 tab., 1 fig.

  3. Determining the Optimum Training Conditions for Selective Strengthening of Vastus Medialis Oblique Muscle over Vastus Lateralis through Using Musculoskeletal Modeling

    Directory of Open Access Journals (Sweden)

    Farzam Farahmand

    2016-09-01

    Full Text Available Objective: The purpose of this study is to find the optimum training conditions for selective strengthening of the vastus medialis oblique muscle over vastus lateralis. Methods: For this purpose, a musculoskeletal model of lower limb was developed by OpenSim software. Using a detailed tibiofemoral and patellofemoral joint modeling and six muscular branches for components of quadriceps femoris muscle on the other hand, training conditions were simulated in isometric, isokinetic and isotonic modes. For each training condition, the motion kinematic and external force was applied to the model. After analyzing the inverse dynamics, the force of each component of quadriceps femoris muscle was obtained through the statical optimization. Impact of knee angle, speed of movement, external loading level and axial tibial rotation on activity rate of vastus medialis oblique to vastus lateralis muscle was investigated based on the model. Results: The results showed that the knee angle affect on this ratio and the highest ratio could be obtained in angles close to full extension of knee. Speed of movement and external load level would not affect the ratio. Meanwhile axial tibial rotation could affect this ratio in a way that increasing tibial external rotation was associated with increasing the ratio. Conclusion: The results indicate that high-speed isokinetic training with highest levels of tibial external rotation in angles close to full extension of knee can resulte in increasing the maximum activity ratio of vastus medialis oblique to vastus lateralis muscle.

  4. A Box-Behnken design for determining the optimum experimental condition of the fungicide (Vapam) sorption onto soil modified with perlite.

    Science.gov (United States)

    Azizi, Seyed N; Asemi, Neda

    2012-01-01

    In the present study, response surface methodology (RSM) based on the Box-Behnken design (BBD) was employed to investigate the effects of the different operating conditions on the removal of the fungicide (Vapam) onto soil modified with perlite using sorption process. The process parameters such as pH of the fungicide solution (2, 5 and 8), temperature (15, 25 and 35°C), shaking time (2, 13 and 24 h) and the percentage of perlite in the modified soil (0, 2 and 4 %) were investigated using a four-factor-three-level Box-Behnken design at an initial fungicide concentration of C(0) = 1.6 mg/L as a fixed input parameter. A second-order quadratic model suggested the optimum conditions to be as follows: fungicide solution pH of 3.57, temperature of 15°C, shaking time of 3.5 h and 4% of perlite in the modified soil which resulted in the improvement of Vapam sorption. Under optimum conditions, the fungicide (Vapam) removal was predicted 12.88 μg/g by BBD. The confirmatory experiments were conducted and the results revealed that the fungicide removal was 13.14 μg/g which indicated that the predicted and the observed values of response (Vapam removal) were in close agreement. Therefore, the soil modified with perlite holds good potential for Vapam sorption. This is the first report on fungicide Vapam sorption onto soil modified with perlite using statistical experimental design employing response surface methodology.

  5. Optimum Conditions for Introducing Free Radical Polymerizable Methacrylate Groups on the MWCNT Surface by Michael Addition Reaction

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sunghoon; Park, Seonghwan; Kwon, Jaebeom; Ha, KiRyong [Keimyung University, Daegu (Korea, Republic of)

    2015-02-15

    In this study, we investigated optimum conditions for the introduction of a lot of free radical polymerizable methacrylate groups on the multi-walled carbon nanotube (MWCNT) surface. Carboxyl groups were introduced first on MWCNT surfaces by treating with a mixture of sulfuric acid and nitric acid with ultrasonic bath for 2 hours, and oxidized MWCNTs were reacted further with thionyl chloride followed by triethylenetetramine (TETA) to introduce amino groups on the oxidized MWCNT surface, to make MWCNT-NH{sub 2}. To introduce free radical polymerizable methacrylate groups on the MWCNT-NH{sub 2}, MWCNT-NH{sub 2} was reacted with 3-(acryloyloxy)-2-hydroxypropyl methacrylate (AHM) by Michael addition reaction. We investigated progress of modification reactions for MWCNT by fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and elemental analysis (EA). We found maximum degree of Michael addition reactions between AHM and TETA grafted on MWCNT-NH{sub 2} for 10:1 mol ratio and 8 hour reaction time in our reaction conditions.

  6. Compositional Modeling for Optimum Design of Water-Alternating CO2-LPG EOR under Complicated Wettability Conditions

    Directory of Open Access Journals (Sweden)

    Jinhyung Cho

    2015-01-01

    Full Text Available The addition of LPG to the CO2 stream leads to minimum miscible pressure (MMP reduction that causes more oil swelling and interfacial tension reduction compared to CO2 EOR, resulting in improved oil recovery. Numerical study based on compositional simulation has been performed to examine the injectivity efficiency and transport behavior of water-alternating CO2-LPG EOR. Based on oil, CO2, and LPG prices, optimum LPG concentration and composition were designed for different wettability conditions. Results from this study indicate how injected LPG mole fraction and butane content in LPG affect lowering of interfacial tension. Interfacial tension reduction by supplement of LPG components leads to miscible condition causing more enhanced oil recovery. The maximum enhancement of oil recovery for oil-wet reservoir is 50% which is greater than 22% for water-wet reservoir. According to the result of net present value (NPV analysis at designated oil, CO2, propane, and butane prices, the optimal injected LPG mole fraction and composition exist for maximum NPV. At the case of maximum NPV for oil-wet reservoir, the LPG fraction is about 25% in which compositions of propane and butane are 37% and 63%, respectively. For water-wet reservoir, the LPG fraction is 20% and compositions of propane and butane are 0% and 100%.

  7. Determining the Optimum Exposure and Recovery Periods for Efficient Operation of a QCM Based Elemental Mercury Vapor Sensor

    Directory of Open Access Journals (Sweden)

    K. M. Mohibul Kabir

    2015-01-01

    Full Text Available In recent years, mass based transducers such as quartz crystal microbalance (QCM have gained huge interest as potential sensors for online detection of elemental mercury (Hg0 vapor from anthropogenic sources due to their high portability and robust nature enabling them to withstand harsh industrial environments. In this study, we determined the optimal Hg0 exposure and recovery times of a QCM based sensor for ensuring its efficient operation while monitoring low concentrations of Hg0 vapor (<400 ppbv. The developed sensor was based on an AT-cut quartz substrate and utilized two gold (Au films on either side of the substrate which functions as the electrodes and selective layer simultaneously. Given the temporal response mechanisms associated with mass based mercury sensors, the experiments involved the variation of Hg0 vapor exposure periods while keeping the recovery time constant following each exposure and vice versa. The results indicated that an optimum exposure and recovery periods of 30 and 90 minutes, respectively, can be utilized to acquire the highest response magnitudes and recovery rate towards a certain concentration of Hg0 vapor whilst keeping the time it takes to report an accurate reading by the sensor to a minimum level as required in real-world applications.

  8. Operant conditioning of autobiographical memory retrieval.

    Science.gov (United States)

    Debeer, Elise; Raes, Filip; Williams, J Mark G; Craeynest, Miet; Hermans, Dirk

    2014-01-01

    Functional avoidance is considered as one of the key mechanisms underlying overgeneral autobiographical memory (OGM). According to this view OGM is regarded as a learned cognitive avoidance strategy, based on principles of operant conditioning; i.e., individuals learn to avoid the emotionally painful consequences associated with the retrieval of specific negative memories. The aim of the present study was to test one of the basic assumptions of the functional avoidance account, namely that autobiographical memory retrieval can be brought under operant control. Here 41 students were instructed to retrieve personal memories in response to 60 emotional cue words. Depending on the condition, they were punished with an aversive sound for the retrieval of specific or nonspecific memories in an operant conditioning procedure. Analyzes showed that the course of memory specificity significantly differed between conditions. After the procedure participants punished for nonspecific memories retrieved significantly more specific memories compared to participants punished for specific memories. However, whereas memory specificity significantly increased in participants punished for specific memories, it did not significantly decrease in participants punished for nonspecific memories. Thus, while our findings indicate that autobiographical memory retrieval can be brought under operant control, they do not support a functional avoidance view on OGM.

  9. Increased power generation from primary sludge by a submersible microbial fuel cell and optimum operational conditions

    DEFF Research Database (Denmark)

    Vologni, Valentina; Kakarla, Ramesh; Angelidaki, Irini;

    2013-01-01

    Microbial fuel cells (MFCs) have received attention as a promising renewable energy technology for waste treatment and energy recovery. We tested a submersible MFC with an innovative design capable of generating a stable voltage of 0.250 ± 0.008 V (with a fixed 470 Ω resistor) directly from primary...

  10. 植酸酶液体发酵条件研究%Optimum conditions for phytase liquid fermentation

    Institute of Scientific and Technical Information of China (English)

    汪世华; 杨燕凌; 胡开辉

    2006-01-01

    对绿色木霉LH374液体发酵生产植酸酶的条件作了研究,确立了所试因素的最佳组合:碳源为5%葡萄糖,氮源为3%胰蛋白胨和0.3%硝酸铵,金属离子为0.003%Fe2++0.003%Mn2+.每500 mL三角瓶装50 mL培养基,初始pH为6.5,接种量为5%.在最适条件下发酵72 h生成植酸酶的最高产量为2510 U·mL-1,平均产量为2490 U·mL-1.%Optimization of the fermentation medium for maximum phytase production was carried out using a new strain, Trichoderma viride LH374, and the test results were listed as follows: carbon source was 5% glucose, nitrogen source were 3% tryptone and 0.3% NH4NO3, and metallic ion concentration were 0.003% Fe2+ and 0.003% Mn2+. The 500 mL flasks were filled with 50 mL media with pH 6.5 to incubate 72 h, and inoculation amount was 5%. Under optimum condition, Trichoderma viride LH374 was able to yield the maximum phytase activity of 2510 U·mL-1 and the average of 2490 U·mL-1 phytase.

  11. OPTIMUM PROSESSENTRERING

    Directory of Open Access Journals (Sweden)

    K. Adendorff

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: The paper derives an expression for optimum process centreing for a given design specification and spoilage and/or rework costs.

    AFRIKAANSE OPSOMMING: Die problem Van prosessentrering vir n gegewe ontwerpspesifikasie en herwerk- en/of skrootkoste word behandel.

  12. Effect of operating conditions on gearbox noise

    Science.gov (United States)

    Oswald, Fred B.; Zakrajsek, James J.; Townsend, Dennis P.; Atherton, William; Lin, Hsiang Hsi

    1992-04-01

    Low contact ratio spur gears were tested in the NASA gear noise rig to study the noise radiated from the top of the gearbox. The measured sound power from the gearbox top was obtained from a near field acoustic intensity scan taken at 63 nodes just above the surface. The sound power was measured at a matrix of 45 operating speeds and torque levels. Results are presented in the form of a spectral speed map and as a plot of sound power versus torque (at constant speed) and as sound power versus speed (at constant torque). Because of the presence of vibration modes, operating speed was found to have more impact on noise generation than torque level. A NASA gear dynamics code was used to compute the gear tooth dynamic overload at the same 45 operating conditions used for the experiment. Similar trends were found between the analytical results for dynamic tooth overload and experimental results for sound power. Dynamic analysis may be used to design high quality gears with profile relief optimized for minimum dynamic load and noise.

  13. The operational meaning of quantum conditional information

    CERN Document Server

    Devetak, I; Devetak, Igor; Yard, Jon

    2006-01-01

    With a statistical view towards information and noise, information theory derives ultimate limitations on information processing tasks. These limits are generally expressed in terms of entropic measures of information and correlations. Here we answer the quantum information-theoretic question: ``How correlated are two quantum systems from the perspective of a third?" by solving the following `quantum state redistribution' problem. Given an arbitrary quantum state of three systems, where Alice holds two and Bob holds one, what is the cost, in terms of quantum communication and entanglement, for Alice to give one of her parts to Bob? The communication cost gives the first operational interpretation to quantum conditional mutual information. The optimal procedure is self-dual under time reversal and is perfectly composable. This generalizes known protocols such as the state merging and fully quantum Slepian-Wolf protocols, from which almost every known protocol in quantum Shannon theory can be derived.

  14. Determination of Optimum Conditions for the Production of Activated Carbon Derived from Separate Varieties of Coconut Shells

    Directory of Open Access Journals (Sweden)

    E. S. Sanni

    2017-01-01

    Full Text Available Activated carbons were produced from coconut shells of tall and dwarf tree varieties. The activated carbon from the tall tree variety was initially synthesized using 1 M concentration of each of ZnCl2, H3PO4, and KOH solutions. From the adsorptive tests conducted using methylene blue solution, the activated carbon produced with H3PO4 gave the best absorbance and adsorptive performance. Coconut shells of dwarf tree variety were then obtained and treated with same mass of coconut shells of the tall tree variety using varied concentrations of the acid in order to determine whether the optimum concentration and temperature for producing carbon black from the coconut shells are distinct or similar for both varieties. The process was also modelled using the Differential Response Method (DRM in order to determine the yields and adsorptive performances of the activated carbons by varying the carbonization temperature and concentration. The results from experiment and the developed mathematical model were both found to be in agreement giving the optimum concentration of phosphoric acid and pH for producing activated carbon to be 0.67 M and 2.07 for the tall tree variety and 1 M and 1.98 for the dwarf variety at optimum temperatures in the range of 450–575°C and 575°C, respectively.

  15. MSTAR extended operating conditions: a tutorial

    Science.gov (United States)

    Keydel, Eric R.; Lee, Shung W.; Moore, John T.

    1996-06-01

    One key advantage of the model-based approach for automatic target recognition (ATR) is the wide range of targets and acquisition scenarios that can be accommodated without algorithm re-training. This accrues from the use of predictive models which can be adjusted to hypothesized scenarios on-line. Approaches which rely on measured signature exemplars as the source of reference data for signature matching are constrained to those scenarios represented in the reference data base. The moving and stationary target recognition (MSTAR) program will advance the state-of-the-art in model-based ATR by developing, evaluating, and testing algorithm performance against a set of extended operating conditions (EOCs) designed to reflect real-world battlefield scenarios. In addition to full 360 deg target aspect coverage over a range of depression angles, the EOCs include variations in squint angle, target articulation and configurations, obscuration due to occlusion and/or layover, and intra-class target variability. These conditions can have a profound impact on the nature of the target signature, necessitating the development of explicit prediction and reasoning algorithms to provide robust target recognition. This paper provides a tutorial description of the impact of the MSTAR EOCs on SAR target signatures. A brief background discussion of the SAR imaging process is presented first. This is followed by a description of the impact of each EOC category on the target signature along with synthetic imagery examples to illustrate this impact.

  16. Seasonal Variation in Shell Calcification of Planktonic Foraminifera in the NE Atlantic Reveals Species-Specific Response to Temperature, Productivity, and Optimum Growth Conditions.

    Science.gov (United States)

    Weinkauf, Manuel F G; Kunze, José G; Waniek, Joanna J; Kučera, Michal

    2016-01-01

    Using shells collected from a sediment trap series in the Madeira Basin, we investigate the effects of seasonal variation of temperature, productivity, and optimum growth conditions on calcification in three species of planktonic Foraminifera. The series covers an entire seasonal cycle and reflects conditions at the edge of the distribution of the studied species, manifesting more suitable growth conditions during different parts of the year. The seasonal variation in seawater carbonate saturation at the studied site is negligible compared to other oceanic regions, allowing us to assess the effect of parameters other than carbonate saturation. Shell calcification is quantified using weight and size of individual shells. The size-weight scaling within each species is robust against changes in environmental parameters, but differs among species. An analysis of the variation in calcification intensity (size-normalized weight) reveals species-specific response patterns. In Globigerinoides ruber (white) and Globigerinoides elongatus, calcification intensity is correlated with temperature (positive) and productivity (negative), whilst in Globigerina bulloides no environmental forcing is observed. The size-weight scaling, calcification intensity, and response of calcification intensity to environmental change differed between G. ruber (white) and G. elongatus, implying that patterns extracted from pooled analyses of these species may reflect their changing proportions in the samples. Using shell flux as a measure of optimum growth conditions, we observe significant positive correlation with calcification intensity in G. elongatus, but negative correlation in G. bulloides. The lack of a consistent response of calcification intensity to optimum growth conditions is mirrored by the results of shell size analyses. We conclude that calcification intensity in planktonic Foraminifera is affected by factors other than carbonate saturation. These factors include temperature

  17. LHCb Conditions database operation assistance systems

    Science.gov (United States)

    Clemencic, M.; Shapoval, I.; Cattaneo, M.; Degaudenzi, H.; Santinelli, R.

    2012-12-01

    The Conditions Database (CondDB) of the LHCb experiment provides versioned, time dependent geometry and conditions data for all LHCb data processing applications (simulation, high level trigger (HLT), reconstruction, analysis) in a heterogeneous computing environment ranging from user laptops to the HLT farm and the Grid. These different use cases impose front-end support for multiple database technologies (Oracle and SQLite are used). Sophisticated distribution tools are required to ensure timely and robust delivery of updates to all environments. The content of the database has to be managed to ensure that updates are internally consistent and externally compatible with multiple versions of the physics application software. In this paper we describe three systems that we have developed to address these issues. The first system is a CondDB state tracking extension to the Oracle 3D Streams replication technology, to trap cases when the CondDB replication was corrupted. Second, an automated distribution system for the SQLite-based CondDB, providing also smart backup and checkout mechanisms for the CondDB managers and LHCb users respectively. And, finally, a system to verify and monitor the internal (CondDB self-consistency) and external (LHCb physics software vs. CondDB) compatibility. The former two systems are used in production in the LHCb experiment and have achieved the desired goal of higher flexibility and robustness for the management and operation of the CondDB. The latter one has been fully designed and is passing currently to the implementation stage.

  18. Prediction and Optimization Approaches for Modeling and Selection of Optimum Machining Parameters in CNC down Milling Operation

    Directory of Open Access Journals (Sweden)

    Asaad A. Abdullah

    2014-04-01

    Full Text Available In this study, we suggested intelligent approach to predict and optimize the cutting parameters when down milling of 45# steel material with cutting tool PTHK- (Ø10*20C*10D*75L -4F-1.0R under dry condition. The experiments were performed statistically according to four factors with three levels in Taguchi experimental design method. Adaptive Neuro-fuzzy inference system is utilized to establish the relationship between the inputs and output parameter exploiting the Taguchi orthogonal array L27. The Particle Swarm Optimized-Adaptive Neuro-Fuzzy Inference System (PSOANFIS is suggested to select the best cutting parameters providing the lower surface through from the experimental data using ANFIS models to predict objective functions. The PSOANFIS optimization approach that improves the surface quality from 0.212 to 0.202, as well as the cutting time is also reduced from 7.5 to 4.78 sec according to machining parameters before and after optimization process. From these results, it can be readily achieved that the advanced study is trusted and suitable for solving other problems encountered in metal cutting operations and the same surface roughness.

  19. THE BEST AND OPTIMUM CONDITIONS TO OBTAINING MNFE2O4 AND ITS INVENTIONAL OF NUCLEAR AND FERROMAGNETIC RELAXATION

    Directory of Open Access Journals (Sweden)

    Rohollah Soleimani

    2012-07-01

    Full Text Available In this study, Mn-ferrite has been prepared with nominal formula of MnFe2O4, using the dry conventional ceramic method. The raw materials were Mobarakeh steel company modified domestic iron oxide and Merckmanganese oxide. XRD patterns of the prepared samples show that they are single phase. Magnetic measurements have been performed on the toroidal samples sintered in different temperatures, using ahystograph unit MPG100D model. The results of measurements show that optimum formation pressures to obtain maximum relative magnetic permeability and hystersis. The Mn55 nuclear spin- lattice relaxation, and the ferromagnetic resonance linewidth have been studied in the same single crystal of ferromagnetic as a function ofthe temperature.

  20. Estimation of Uptake of Humic Substances from Different Sources by Escherichia coli Cells under Optimum and Salt Stress Conditions by Use of Tritium-Labeled Humic Materials▿

    Science.gov (United States)

    Kulikova, Natalia A.; Perminova, Irina V.; Badun, Gennady A.; Chernysheva, Maria G.; Koroleva, Olga V.; Tsvetkova, Eugenia A.

    2010-01-01

    The primary goal of this paper is to demonstrate potential strengths of the use of tritium-labeled humic substances (HS) to quantify their interaction with living cells under various conditions. A novel approach was taken to study the interaction between a model microorganism and the labeled humic material. The bacterium Escherichia coli was used as a model microorganism. Salt stress was used to study interactions of HS with living cells under nonoptimum conditions. Six tritium-labeled samples of HS originating from coal, peat, and soil were examined. To quantify their interaction with E. coli cells, bioconcentration factors (BCF) were calculated and the amount of HS that penetrated into the cell interior was determined, and the liquid scintillation counting technique was used as well. The BCF values under optimum conditions varied from 0.9 to 13.1 liters kg−1 of cell biomass, whereas under salt stress conditions the range of corresponding values increased substantially and accounted for 0.2 to 130 liters kg−1. The measured amounts of HS that penetrated into the cells were 23 to 167 mg and 25 to 465 mg HS per kg of cell biomass under optimum and salt stress conditions, respectively. This finding indicated increased penetration of HS into E. coli cells under salt stress. PMID:20639375

  1. Control of Propeller Cavitation in Operational Conditions

    NARCIS (Netherlands)

    Vrijdag, A.

    2009-01-01

    Off design conditions can have a severe impact on ship propulsion system behaviour. Resistance increase for instance leads to a higher engine loading, and can also easily lead to a decrease of cavitation inception speed with respect to calm water conditions. Wakefield variations due to ship motions,

  2. Application of experimental design and response surface technique for selecting the optimum RP-HPLC conditions for the determination of moxifloxacin HCl and ketorolac tromethamine in eye drops

    Directory of Open Access Journals (Sweden)

    Pradipbhai D. Kalariya

    2017-01-01

    Full Text Available A method has been developed for the separation of moxifloxacin HCl and ketorolac tromethamine using reverse phase high-performance liquid chromatography (RP-HPLC on C18 column (250 × 4.6 mm, 5 μm with UV detection at 308 nm. Experimental designs were applied for multivariate optimization of the experimental conditions of RP-HPLC method. Three independent factors: methanol content in the mobile phase composition, buffer pH and flow rate were used to design mathematical models. Here faced central composite (FCC experimental design was used to study the response surface technique and to study in depth the effects of these independent factors. Derringer’s desirability function was applied to simultaneously optimize the retention time of last eluting peak (ketorolac tromethamine and tailing factor of moxifloxacin. The predicted optimum assay condition consisted of methanol and potassium dihydrogen phosphate buffer (pH 3.2; 25 mM, 0.5% Triethylamine in a proportion of 60:40% v/v, respectively, as the mobile phase at a flow rate of 1.2 mL min−1. Using this optimum condition, baseline separation of both drugs with good resolution and a run time of less than 7 min were achieved. The optimized assay condition was validated according to ICH guidelines to confirm specificity, linearity, accuracy and precision.

  3. A systems integration approach to the optimum operation and scheduling of biocide usage and discharge for seawater cooling systems

    KAUST Repository

    Mahfouz, Abdullah Bin

    2012-01-01

    The objective of this work is to develop a systematic approach to the optimal design and integration of seawater cooling systems in industrial facilities along with the usage and discharge of biocides. Specifically, the paper will address the following tasks: 1 identification of the reaction pathways for the biocide from the mixing basin to the discharge points 2 kinetic modelling of the biocide and by-products throughout the process 3 a process integration framework to provide a holistic approach to optimising the design and operation of the seawater cooling systems, along with the dosage and discharge systems. A hierarchical procedure is developed to first identify design modifications for heat integration and energy efficiency. Then, a multi-period, multi-segment optimisation formulation is developed and solved to identify the optimal operation and scheduling of biocide usage and discharge. A case study is solved to illustrate the applicability of the devised approach.

  4. LHCb Conditions Database Operation Assistance Systems

    CERN Multimedia

    Shapoval, Illya

    2012-01-01

    The Conditions Database of the LHCb experiment (CondDB) provides versioned, time dependent geometry and conditions data for all LHCb data processing applications (simulation, high level trigger, reconstruction, analysis) in a heterogeneous computing environment ranging from user laptops to the HLT farm and the Grid. These different use cases impose front-end support for multiple database technologies (Oracle and SQLite are used). Sophisticated distribution tools are required to ensure timely and robust delivery of updates to all environments. The content of the database has to be managed to ensure that updates are internally consistent and externally compatible with multiple versions of the physics application software. In this paper we describe three systems that we have developed to address these issues: - an extension to the automatic content validation done by the “Oracle Streams” replication technology, to trap cases when the replication was unsuccessful; - an automated distribution process for the S...

  5. Poor weather conditions and flight operations: Implications for air ...

    African Journals Online (AJOL)

    Poor weather conditions and flight operations: Implications for air transport hazard ... Ethiopian Journal of Environmental Studies and Management ... fog, dust haze and line squall that affect flight operation such as flight delays, diversion and ...

  6. 新银合欢中单宁提取工艺优化研究%Optimum conditions on extraction of tannin from Leucaena leucocephala

    Institute of Scientific and Technical Information of China (English)

    李茂; 字学娟; 周汉林; 刘国道

    2012-01-01

    对新银合欢(Leucaena leucoce phala)中单宁类物质的提取工艺进行优化研究,选择液料比、提取温度、提取时间、提取剂体积分数等因素分别进行单因素和正交试验。结果表明,在液料比40:1、提取温度50℃、提取时间60min、丙酮体积分数50%的条件下,单宁提取效果最佳,测得新银合欢单宁平均含量为2.54%。%The optimum conditions, including four main factors: ratio of liquid to material, extraction tern perature, extraction time and extractant concentration, for extracting tannins from leaves and stems of Leucaena Zeucocephala were optimized by using a combined method of single factor analysis and orthogonal experiment design. The results showed that the optimum conditions of each factor in tannin extraction were: ratio of liquid to material 40 : 1, extraction temperature 50℃, extraction time 40 rain and acetone concentration 50%. The extracting rate of the tannin from the leaves and stems of L. leucocephala was 2. 54%.

  7. Application of Ultrasound in a Closed System: Optimum Condition for Antioxidants Extraction of Blackberry (Rubus fructicosus) Residues

    OpenAIRE

    2016-01-01

    Blackberry processing generates up to 20% of residues composed mainly of peel, seeds and pulp that are abundant in flavonoids. The objective of this study was to optimize the ultrasound conditions, in a closed system, for antioxidants extraction, using the response surface methodology. Blackberry (Rubus fructicosus) residues were analyzed for total phenolics, total anthocyanins, and antioxidant activity by ABTS and DPPH. The selected independent variables were ultrasound amplitude (X1: 80%–90...

  8. Operational conditions for random-number generation

    Science.gov (United States)

    Compagner, A.

    1995-11-01

    Ensemble theory is used to describe arbitrary sequences of integers, whether formed by the decimals of π or produced by a roulette or by any other means. Correlation coefficients of any range and order are defined as Fourier transforms of the ensemble weights. Competing definitions of random sequences are considered. Special attention is given to sequences of random numbers needed for Monte Carlo calculations. Different recipes for those sequences lead to correlations that vary in range and order, but the total amount of correlation is the same for all sequences of a given length (without internal periodicities). For maximum-length sequences produced by linear algorithms, most correlation coefficients are zero, but the remaining ones are of absolute value 1. In well-tempered sequences, these complete correlations are of high order or of very long range. General conditions to be obeyed by random-number generators are discussed and a qualitative method for comparing different recipes is given.

  9. Application of Ultrasound in a Closed System: Optimum Condition for Antioxidants Extraction of Blackberry (Rubus fructicosus Residues

    Directory of Open Access Journals (Sweden)

    Quinatzin Y. Zafra-Rojas

    2016-07-01

    Full Text Available Blackberry processing generates up to 20% of residues composed mainly of peel, seeds and pulp that are abundant in flavonoids. The objective of this study was to optimize the ultrasound conditions, in a closed system, for antioxidants extraction, using the response surface methodology. Blackberry (Rubus fructicosus residues were analyzed for total phenolics, total anthocyanins, and antioxidant activity by ABTS and DPPH. The selected independent variables were ultrasound amplitude (X1: 80%–90% and extraction time (X2: 10–15 min, and results were compared with conventional extraction methods. The optimal conditions for antioxidants extraction were 91% amplitude for 15 min. The results for total phenolic content and anthocyanins and antioxidant activity by ABTS and DPPH were of 1201.23 mg gallic acid equivalent (GAE/100 g dry weight basis (dw; 379.12 mg/100 g·dw; 6318.98 µmol Trolox equivalent (TE/100 g·dw and 9617.22 µmol TE/100 g·dw, respectively. Compared to solvent extraction methods (water and ethanol, ultrasound achieved higher extraction of all compounds except for anthocyanins. The results obtained demonstrated that ultrasound is an alternative to improve extraction yield of antioxidants from fruit residues such as blackberry.

  10. Optimum air conditioning by h,x-directed controller; Optimales Klima durch h,x-gefuehrte Regelung

    Energy Technology Data Exchange (ETDEWEB)

    Bachmann, G.; Schumacher, B. [Landis und Staefa AG, Staefa (Switzerland)

    1997-11-01

    The new `Economiser tx2` h,x-directed controller optimises control of air conditioning systems by including all process variables (heating, cooling, humidification, dehumidification) in the control strategy. Adjustments to the energy recovery and humidification system, and to the energy cost situation - e.g. cooling with a chiller or with sea water - can be implemented. At the same time, particular customer wishes can be fulfilled, for example, the size of the size of the comfort field can be increased or reduced. Cost savings of 10 to 60%, with improved comfort, are possible in comparison with conventional air conditioning control systems. The closed control strategy guarantees good dynamic behaviour and thus less wear and tear on the system. (orig.) [Deutsch] Die Strategie zur Regelung von Klimaanlagen hat sich in den letzten 20 Jahren wenig geaendert. Typisch ist zum Beispiel die Steuerung der Energierueckgewinnung nach der Enthalpie oder die Aufteilung in einen Temperatur- und Feuchteregelkreis mit jeweils energieneutralen Zonen ohne gegenseitige Abstimmung. Hier liegt zweifellos ein Optimierungspotential brach. Mit einem neuen Regelungskonzept, das sich auf das Behaglichkeitsfeld stuetzt und die spezifischen Kosten fuer die Funktionen Heizen, Kuehlen, Befeuchten und Entfeuchten in die Regelstrategie einbezieht, lassen sich ohne Komfortverzicht Energieeinsparungen von bis zu 60 Prozent erzielen. (orig.)

  11. Kinetic characterization, optimum conditions for catalysis and substrate preference of secretory phospholipase A2 from Glycine max in model membrane systems.

    Science.gov (United States)

    Mariani, María Elisa; Madoery, Ricardo Román; Fidelio, Gerardo Daniel

    2015-01-01

    Two secretory phospholipase A2 (sPLA2s) from Glycine max, GmsPLA2-IXA-1 and GmsPLA2-XIB-2, have been purified as recombinant proteins and the activity was evaluated in order to obtain the optimum conditions for catalysis using mixed micelles and lipid monolayers as substrate. Both sPLA2s showed a maximum enzyme activity at pH 7 and a requirement of Ca(2+) in the micromolar range. These parameters were similar to those found for animal sPLA2s but a surprising optimum temperature for catalysis at 60 °C was observed. The effect of negative interfacial charges on the hydrolysis of organized substrates was evaluated through initial rate measurements using short chain phospholipids with different head groups. The enzymes showed subtle differences in the specificity for phospholipids with different head groups (DLPC, DLPG, DLPE, DLPA) in presence or absence of NaCl. Both recombinant enzymes showed lower activity toward anionic phospholipids and a preference for the zwitterionic ones. The values of the apparent kinetic parameters (Vmax and KM) demonstrated that these enzymes have more affinity for phosphatidylcholine compared with phosphatidylglycerol, in contrast with the results observed for pancreatic sPLA2. A hopping mode of catalysis was proposed for the action of these sPLA2 on mixed phospholipid/triton micelles. On the other hand, Langmuir-monolayers assays indicated an optimum lateral surface pressure for activity in between 13 and 16 mN/m for both recombinant enzymes. Copyright © 2014 Elsevier B.V. and Société française de biochimie et biologie Moléculaire (SFBBM). All rights reserved.

  12. The determination of optimum condition in water hyacinth drying process by mixed adsorption drying method and modified fly ash as an adsorbent

    Science.gov (United States)

    Saputra, Asep Handaya; Putri, Rizky Anggreini

    2017-05-01

    Water hyacinth is an aquatic weed that has a very fast growth which makes it becomes a problem to the ecosystem. On the other hand, water hyacinth has a high fiber content (up to 20% by weight) which makes it potential to become raw material for composites and textile industries. As an aquatic plant, water hyacinth has a high initial moisture content that reaches more than 90%. Meanwhile the moisture content of fiber as a raw material for composite and textile industry should not be more than 10% to maintain the good quality of the products. Mixed adsorption drying method is one of the innovative method that can replace conventional drying process. Fluidization method which has been commonly used in agricultural and pharmaceutical products drying, can be enhanced by combining it with the adsorption method as performed in this study. In mixed fluidization-adsorption drying method, fly ash as adsorbent and water hyacinth fiber were put together into the fluidization column where the drying air evaporate the moisture content in water hyacinth fiber. In addition, the adsorbent adsorb the moisture content in the drying air to make the moisture content of the drying air remain low. The drying process is performed in various temperature and composition of water hyacinth and adsorbent in order to obtain the optimum drying condition. In addition, the effect of fly ash pellet and fly ash powder to the drying process was also performed. The result shows that the higher temperature and the more amount of adsorbent results in the faster drying rate. Fly ash pellet shows a better adsorption since it has a smaller pore diameter and wider surface area. The optimum temperature obtained from this study is 60°C and the optimum ratio of water hyacinth and fly ash is 50:50.

  13. Three-Dimensional Wind Field Analysis from Dual-Doppler Radar Data. Part III: The Boundary Condition: An Optimum Determination Based on a Variational Concept.

    Science.gov (United States)

    Chong, M.; Testud, J.

    1983-07-01

    The choice of the boundary condition when integrating the air mass continuity equation, is a major problem of the 3D wind field analysis from dual (or multiple) Doppler radar data. A zero vertical velocity at ground level seems the most natural boundary condition. Unfortunately, it is known that the integration processes is unstable with respect to this condition: it leads to errors amplifying exponentially with height. In order to overcome this difficulty various solutions have been proposed, the most recent ones using the variational analysis: (i) integrating from storm top level, (ii) integrating from storm top level while constraining the height integrated divergence to be as small as possible (Ziegier, 1978), and (iii) constraining the direct estimates of the 3D wind field to satisfy the continuity equation (Ray et al., 1980). The analysis proposed in this paper is also based upon a variational concept, but it differs in its principle from those previously cited. It consists in adjusting the boundary condition field at ground level in order to optimize the `mathematical regularity' of the vertical velocity field, followed by upward integration of the continuity equation. In such a formulation, the boundary condition at ground level is `floating' (i.e., not specified). However it is possible to require. as a subsidiary condition of the variational problem, that the vertical velocity at ground level fluctuate about zero with a specified variance 02 (thus the condition W0=0 at ground level is statistically verified). The optimum choice of 0 is established from considerations of statistical theory. It should be noted that the horizontal divergence (or coplane divergence) profile is unadjusted and that the equation of continuity is integrated upward from the optimum lower boundary condition to obtain W.An application to simulated or real data helps us to appreciate the improvements brought by the present variational approach with respect to standard methods of

  14. Selection of optimum conditions of medium acidity and aeration for submerget cultivation of Bacillus thuringiensis and Beauveria bassiana

    Directory of Open Access Journals (Sweden)

    O. A. Dregval

    2010-06-01

    Full Text Available The paper deals with the influence of medium pH and aeration rate on growth and sporulation of Bacillus thuringiensis and Вeauveria bassiana, which are main constituents of the complex microbial insecticide. It was established optimal medium pH for B. thuringiensis – 6.0 and for В. bassiana – 6.0–7.0. The maximum productivity of the studied microorganisms was observed in the same range of aeration – 7– 14 mmol O2/l/h. The selected conditions of cultivation are necessary for the production of complex biological insecticide based on the association of B. thuringiensis and B. bassiana.

  15. Optimum performance of the small scale open and direct solar thermal Brayton cycle at various environmental conditions and constraints

    Energy Technology Data Exchange (ETDEWEB)

    Le Roux, W.G.; Bello-Ochende, T.; Meyer, J.P. [Department of Mechanical and Aeronautical Engineering, University of Pretoria, (South Africa)

    2011-07-01

    The energy of the sun can be transformed into mechanical power through the use of concentrated solar power systems. The use of the Brayton cycle with recuperator has significant advantages but also raises issues such as pressure loss and low net power output which are mainly due to irreversibilities of heat transfer and fluid friction. The aim of this study is to optimize the system to generate maximum net power output. Thermodynamic and dynamic trajectory optimizations were performed on a dish concentrator and an off-the-shelf micro-turbine and the effects of wind, solar irradiance and other environmental conditions and constraints on the power output were analyzed. Results showed that the maximum power output is increased when wind decreases and irradiance increases; solar irradiance was found to have a more significant impact than wind. This study highlighted the factors which impact the power generation of concentrated solar power systems so that designers can take them into account.

  16. 49 CFR 325.35 - Ambient conditions; highway operations.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Ambient conditions; highway operations. 325.35... Ambient conditions; highway operations. (a)(1) Sound. The ambient A-weighted sound level at the microphone... § 325.23. (2) The measured ambient level must be 10 dB(A) or more below that level specified in §...

  17. Transformer real-time reliability model based on operating conditions

    Institute of Scientific and Technical Information of China (English)

    HE Jian; CHENG Lin; SUN Yuan-zhang

    2007-01-01

    Operational reliability evaluation theory reflects real-time reliability level of power system. The component failure rate varies with operating conditions. The impact of real-time operating conditions such as ambient temperature and transformer MVA (megavolt-ampere) loading on transformer insulation life is studied in this paper. The formula of transformer failure rate based on the winding hottest-spot temperature (HST) is given. Thus the real-time reliability model of transformer based on operating conditions is presented. The work is illustrated using the 1979 IEEE Reliability Test System. The changes of operating conditions are simulated by using hourly load curve and temperature curve, so the curves of real-time reliability indices are obtained by using operational reliability evaluation.

  18. Optimum testing of multiple hypotheses in quantum detection theory

    Science.gov (United States)

    Yuen, H. P.; Kennedy, R. S.; Lax, M.

    1975-01-01

    The problem of specifying the optimum quantum detector in multiple hypotheses testing is considered for application to optical communications. The quantum digital detection problem is formulated as a linear programming problem on an infinite-dimensional space. A necessary and sufficient condition is derived by the application of a general duality theorem specifying the optimum detector in terms of a set of linear operator equations and inequalities. Existence of the optimum quantum detector is also established. The optimality of commuting detection operators is discussed in some examples. The structure and performance of the optimal receiver are derived for the quantum detection of narrow-band coherent orthogonal and simplex signals. It is shown that modal photon counting is asymptotically optimum in the limit of a large signaling alphabet and that the capacity goes to infinity in the absence of a bandwidth limitation.

  19. approach to gearbox diagnosis under variable operating conditions

    Directory of Open Access Journals (Sweden)

    Lixiang Duan

    2016-08-01

    Full Text Available Gearbox diagnosis under stationary operating conditions has been extensively investigated; however, variable operating conditions such as load and speed changes play important roles in affecting the accuracy of gearbox diagnosis. This article presents an integrative approach of intrinsic time-scale decomposition and hierarchical temporal memory for gearbox diagnosis under variable operating conditions. A total of two modules are emphasized including a feature extraction method and an integrative feature fusion and classification model. Intrinsic time-scale decomposition method is investigated to extract the gearbox features which are insensitive to variable operating conditions, and its performance overcomes the commonly used empirical mode decomposition in terms of decomposition result and computational efficiency. Hierarchical temporal memory integrates feature fusion and pattern classification in one model to autonomously diagnose gearbox defect. Performance comparison among the presented method, back-propagation neural network, support vector machine, and fuzzy c-means clustering using experimental data demonstrate the effectiveness of the presented method.

  20. 14 CFR 135.227 - Icing conditions: Operating limitations.

    Science.gov (United States)

    2010-01-01

    ... OPERATING REQUIREMENTS: COMMUTER AND ON DEMAND OPERATIONS AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT... aircraft that has frost, ice, or snow adhering to any rotor blade, propeller, windshield, wing, stabilizing... may take off an airplane any time conditions are such that frost, ice, or snow may reasonably...

  1. 消化法检验旋毛虫病最适条件的筛选%The Screening of Optimum Conditions of Digestion Method for Detecting Trichinellosis

    Institute of Scientific and Technical Information of China (English)

    吴秀萍; 王迪; 李庶东; 孙召金; 刘明远

    2015-01-01

    Objective] To screen the optimum conditions including sedimentation temperature and sedimentation coefficient in collecting larvae after digestion,providing important reference data to improve the current“digestion method”for detecting trichinellosis in slaughtering animals.[Methods] 12 international reference Trichinella strains in-cluding 8 species and 4 genotypes were used experimentally to infect Balb/c mice,which were killed 40 dpi. The ratio of recovered muscle larvae and total muscle larvae in the digesting fluid were calculated respectively at 4℃and 25℃and at different time points,and then the sedimentation coefficient of different Trichinella species and genotypes were compared and analyzed. [Results] It was found through comparison that the muscle larvae recovery rates differed sig-nificantly in different Trichinella species and genotypes at different sedimentation temperature and time. The optimum conditions of digestion method for the known Trichinella species and genotypes were screened:the digested larvae should be settled at 4℃for at least 45min. [Conclusion] This study demonstrated the current international gold method for detection of Trichinellosis by means of digestion had certain bias resulting in misdetection. The screening optimum conditions of digestion method for detecting different Trichinella species and genotypes in the study provided the reli-able experimental data and reference value to improve international gold digestion method for detecting Trichinella.%[目的]筛选出“消化法”检测旋毛虫病的最适检测条件,即消化后收集虫体所需要的沉降温度和沉降时间,为改善现有屠宰动物旋毛虫病“消化法”检验技术提供重要的参考数据。[方法]将12个旋毛虫国际标准虫株(8个种和4个基因型)感染Balb/c小鼠,感染40天后剖杀,分别在4℃和25℃条件下计算不同时间点的回收肌幼虫百分比,计算不同温度不同时间点收

  2. Pain Report and Pain-Related Evoked Potentials Operantly Conditioned

    NARCIS (Netherlands)

    Lousberg, Richel; Vuurman, Eric; Lamers, Theo; Breukelen, van Gerard; Jongen, Ellen; Rijnen, Heidi; Maessen, Christa; Hermens, Hermie

    2005-01-01

    Objective: The purpose of the present study was to answer the ques- tion whether pain report can be increased and decreased by operant conditioning. We predicted that the conditioned pain effects would remain significant after correction for social desirability and fantasy proneness. Furthermore, we

  3. Pain Report and Pain-Related Evoked Potentials Operantly Conditioned

    NARCIS (Netherlands)

    Lousberg, Richel; Vuurman, Eric; Lamers, Theo; van Breukelen, Gerard; Jongen, Ellen; Rijnen, Heidi; Maessen, Christa; Hermens, Hermanus J.

    Objective: The purpose of the present study was to answer the ques- tion whether pain report can be increased and decreased by operant conditioning. We predicted that the conditioned pain effects would remain significant after correction for social desirability and fantasy proneness. Furthermore, we

  4. Design and Implementation of Air Conditioning System in Operating Room

    Directory of Open Access Journals (Sweden)

    Htet Htet Aung

    2014-10-01

    Full Text Available The system is air conditioning system in operating room. The main objective of the system was implemented to provide air balance and temperature necessary conditions and to control airflow system for ventilation units in operating room. The operation room can be controlled with fuzzy expert system and describes the desired outputs. Input parameters such as temperature, humidity, oxygen and particle are used and output parameters are chosen as air conditioning motor speed and exhaust motor speed. Input parameters of the system are taken into account optimal conditions based on oxygen as medium and other parameters are chosen minimum condition for operating room. The airflow control system is determined the two components: the airflow block and the thermal block for ventilation units in operating room. The mathematical modeling of each such system based on a computational procedure and to combine them together in an efficient manner. Whether it supports to the most suitable control for the system prototype was determined by simulating the operation with varying the number of personnel and duration of time. Finally, according to the combination of temperature and airflow regulations with PI controller, the results of simulation of the entire ventilation unit control system is obtained.

  5. Structural Health Monitoring in Changing Operational Conditions Using Tranmissibility Measurements

    Directory of Open Access Journals (Sweden)

    Christof Devriendt

    2010-01-01

    Full Text Available This article uses frequency domain transmissibility functions for detecting and locating damage in operational conditions. In recent articles numerical and experimental examples were presented and the possibility to use the transmissibility concept for damage detection seemed quite promising. In the work discussed so far, it was assumed that the operational conditions were constant, the structure was excited by a single input in a fixed location. Transmissibility functions, defined as a simple ratio between two measured responses, do depend on the amplitudes or locations of the operational forces. The current techniques fail in the case of changing operational conditions. A suitable operational damage detection method should however be able to detect damage in a very early stage even in the case of changing operational conditions. It will be demonstrated in this paper that, by using only a small frequency band around the resonance frequencies of the structure, the existing methods can still be used in a more robust way. The idea is based on the specific property that the transmissibility functions become independent of the loading condition in the system poles. A numerical and experimental validation will be given.

  6. Investigation of Optimum Polymerization Conditions for Synthesis of Cross-Linked Polyacrylamide-Amphoteric Surfmer Nanocomposites for Polymer Flooding in Sandstone Reservoirs

    Directory of Open Access Journals (Sweden)

    A. N. El-hoshoudy

    2015-01-01

    Full Text Available Currently enhanced oil recovery (EOR technology is getting more attention by many countries since energy crises are getting worse and frightening. Polymer flooding by hydrophobically associated polyacrylamides (HAPAM and its modified silica nanocomposite are a widely implemented technique through enhanced oil recovery (EOR technology. This polymers class can be synthesized by copolymerization of acrylamide (AM, reactive surfmer, functionalized silica nanoparticles, and a hydrophobic cross-linker moiety in the presence of water soluble initiator via heterogeneous emulsion polymerization technique, to form latexes that can be applied during polymer flooding. Chemical structure of the prepared copolymers was proven through different techniques such as Fourier transform infrared spectroscopy (FTIR, and nuclear magnetic spectroscopy (1H&13C-NMR, and molecular weight was measured by gel permeation chromatography. Study of the effects of monomer, surfmer, cross-linker, silica, and initiator concentrations as well as reaction temperature was investigated to determine optimum polymerization conditions through single factor and orthogonal experiments. Evaluation of the prepared copolymers for enhancing recovered oil amount was evaluated by carrying out flooding experiments on one-dimensional sandstone model to determine recovery factor.

  7. Optimum conditions for the formation of Al13 polymer and active chlorine in electrolysis process with Ti/RuO2-TiO2 anodes

    Institute of Scientific and Technical Information of China (English)

    Chengzhi Hu; Huijuan Liu; Jiuhui Qu

    2012-01-01

    A polyaluminum containing a high concentration of Al13 polymer and active chlorine (PACC) was successfully synthesized by a new electrochemical reactor using Ti/RuO2-TiO2 anodes.PACC can potentially be used as a dual-function chemical reagent for water treatment.The obtained results indicated that the formation of Al13 polymer and active chlorine,were the most active components in PACC responsible for coagulation and disinfection respectively.These components were significantly influenced by electrolyte temperature,current density,and stirring rate.It was observed that high electrolyte temperature favored the formation of Al13.Increasing current density and stirring rate resulted in high current efficiency of chlorine evolution,thus favoring the generation of Al13 and active chlorine in PACC.When the PACC (AlT =0.5 mol/L,basicity =2.3) was prepared at the optimum conditions by electrolysis process,the Al13 polymer and active chlorine in product reached above 70% of AlT and 4000 mg/L,respectively.In the pilot scale experiment with raw polyaluminum chloride used as an electrolyte,PACC was successfully prepared and produced a high content of Al13 and active chlorine products.The pilot scale experiment demonstrated a potential industrial approach of PACC preparation.

  8. A Near-Optimum Multiuser Receiver for STBC MC-CDMA Systems Based on Minimum Conditional BER Criterion and Genetic Algorithm-Assisted Channel Estimation

    Directory of Open Access Journals (Sweden)

    Sacchi Claudio

    2011-01-01

    Full Text Available The implementation of efficient baseband receivers characterized by affordable computational load is a crucial point in the development of transmission systems exploiting diversity in different domains. This would be a crucial point in the future development of 4G systems, where space, time, and frequency diversity will be combined together in order to increase system throughput. In this framework, a linear multiuser detector for MC-CDMA systems with Alamouti's Space-Time Block Coding (STBC, which is inspired by the concept of Minimum Conditional Bit Error Rate (MCBER, is proposed. The MCBER combiner has been implemented in adaptive way by using Least-Mean-Square (LMS optimization. The estimation of Channel State Information (CSI, necessary to make practically feasible the MCBER detection, is aided by a Genetic Algorithm (GA. The obtained receiver scheme is near-optimal, as both LMS-based MCBER and GA-assisted channel estimation perform closely to optimum in fulfilling their respective tasks. Simulation results evidenced that the proposed receiver always outperforms state-of-the-art receiver schemes based on EGC and MMSE criterion exploiting the same degree of channel knowledge.

  9. Criteria for the Minimum Operation Length of Internal Forces as a Function of the Development of an Optimum Structure of Machinery Structural Components

    Directory of Open Access Journals (Sweden)

    Fligiel M.

    2016-12-01

    Full Text Available The present study analyzes the operation length of internal forces (DDSW understood as the length of the flow of internal forces along the shortest possible internal routes. The operation length of internal forces is determined on the basis of stresses and the given volume in the constructional space. The minimum DDSW of the structure satisfies the criterial conditions of the most rigid structure, where the potential energy of deformation and the deformation energy potential is the same in the whole volume and thus the potential gradient is zero.

  10. Study on Optimum Conditions of Catechins Extracted from Greentea with Ethano%绿茶中儿茶素的最佳提取条件研究

    Institute of Scientific and Technical Information of China (English)

    陈林

    2012-01-01

    To obtain the optimum conditions of catechins extracted from green tea with ethanol,ethanol concentration,extraction temperature and extraction time were studied.The results showed that the ethanol concentration,extraction temperature,and extraction time affected extraction efficiency.The orthogonal experiment results showed that the optimal conditions for extraction and purification of catechins as follows: ethanol concentration was 75%,extraction temperature was 88.4 ℃,extraction time was 1.5 h,and the factors affecting the effect of catechins extract as follows: 〉extraction temperature〉extraction timeethanol concentration.%为了获得儿茶素乙醇提取工艺的最佳条件,主要研究了乙醇浓度、浸提温度和浸提时间对儿茶素乙醇提取效果的影响。依据儿茶素与香荚兰素的羟醛缩合生成红色产物的显色反应原理,以无机强酸为催化剂,用分光光度法对提取物中儿茶素含量进行测定。结果表明乙醇浓度、浸提温度、浸提时间对提取效果均有影响。正交试验结果表明,儿茶素的最佳提取和纯化条件为:乙醇浓度为75%,浸提温度为88.4℃,浸提时间为1.5 h,影响儿茶素提取效果的因素依次为:浸提温度〉浸提时间〉乙醇浓度。

  11. The optimum efficiency of energy conversion systems in finite-time conditions; Le rendement optimal des convertisseurs d'energie en temps fini

    Energy Technology Data Exchange (ETDEWEB)

    Le Goff, P.; Tondeur, D. [Ecole Nationale Superieure des Industries Chimiques (ENSIC-LSGC), 54 - Villers-les-Nancy (France)

    2001-07-01

    For all energy conversion systems that use any type of energy (mechanical, electrical, chemical, thermal) to produce a useful energy and a dissipated energy, it is shown that the optimum efficiency (which maximizes the useful power produced), is equal to half of the maximum efficiency (of the system which is supposed to be reversible). It is proposed to name this optimum efficiency 'Carnot efficiency' as a generalization of the case of the thermo-mechanical converter. (J.S.)

  12. Selection of efficient operating modes of combines depending on operating conditions

    Energy Technology Data Exchange (ETDEWEB)

    Alshits, Ya.I.; Konovalov, V.I.; Osokin, P.A.

    1983-01-01

    A technique is presented for selecting the efficient operating modes, determining the permissible velocities for movement and productivity of combines and complexes depending on their operating conditions and types of electric motors used. Parameters are presented for efficient operating modes of the coal-recovery combine 2 K52M under different conditions when it is completed by high-momentum electric motor of the type EDK04-5U5 or the motor EDK04-4MU5. Results are presented of experimental operation in the mines of the combines 2K52 with high-momentum electric motors.

  13. System and method of vehicle operating condition management

    Science.gov (United States)

    Sujan, Vivek A.; Vajapeyazula, Phani; Follen, Kenneth; Wu, An; Moffett, Barty L.

    2015-10-20

    A vehicle operating condition profile can be determined over a given route while also considering imposed constraints such as deviation from time targets, deviation from maximum governed speed limits, etc. Given current vehicle speed, engine state and transmission state, the present disclosure optimally manages the engine map and transmission to provide a recommended vehicle operating condition that optimizes fuel consumption in transitioning from one vehicle state to a target state. Exemplary embodiments provide for offline and online optimizations relative to fuel consumption. The benefit is increased freight efficiency in transporting cargo from source to destination by minimizing fuel consumption and maintaining drivability.

  14. Sex differences in learning processes of classical and operant conditioning.

    Science.gov (United States)

    Dalla, Christina; Shors, Tracey J

    2009-05-25

    Males and females learn and remember differently at different times in their lives. These differences occur in most species, from invertebrates to humans. We review here sex differences as they occur in laboratory rodent species. We focus on classical and operant conditioning paradigms, including classical eyeblink conditioning, fear-conditioning, active avoidance and conditioned taste aversion. Sex differences have been reported during acquisition, retention and extinction in most of these paradigms. In general, females perform better than males in the classical eyeblink conditioning, in fear-potentiated startle and in most operant conditioning tasks, such as the active avoidance test. However, in the classical fear-conditioning paradigm, in certain lever-pressing paradigms and in the conditioned taste aversion, males outperform females or are more resistant to extinction. Most sex differences in conditioning are dependent on organizational effects of gonadal hormones during early development of the brain, in addition to modulation by activational effects during puberty and adulthood. Critically, sex differences in performance account for some of the reported effects on learning and these are discussed throughout the review. Because so many mental disorders are more prevalent in one sex than the other, it is important to consider sex differences in learning when applying animal models of learning for these disorders. Finally, we discuss how sex differences in learning continue to alter the brain throughout the lifespan. Thus, sex differences in learning are not only mediated by sex differences in the brain, but also contribute to them.

  15. OPTIMIZATION OF SESAME SEEDS OIL EXTRACTION OPERATING CONDITIONS USING THE RESPONSE SURFACE DESIGN METHODOLOGY

    Directory of Open Access Journals (Sweden)

    HAITHAM OSMAN

    2016-12-01

    Full Text Available This paper applies Response Surface Design (RSD to model the experimental data obtained from the extraction of sesame seeds oil using n-hexane, chloroform and acetone as solvents under different operating conditions. The results obtained revealed that n-hexane outperformed the extraction obtained using chloroform and acetone. The developed model predicted that n-hexane with a rotational speed of 547 rpm and a contact time between the solvent and seeds of 19.46 hours with solvent: seeds ratio of 4.93, yields the optimum oil extracted of 37.03 %, outperforming chloroform and acetone models that gave prediction for 4.75 and 4.21 respectively. While the maximum predictions yield for chloroform is 6.73 %, under the operating conditions of 602 rpm, and 24 hours contact time, with a ratio of solvent: seeds of 1.74. On the other hand the acetone maximum prediction is only 4.37 %, with operational conditions of 467 rpm, and 6.00 hours contact time, with a ratio of solvent: seeds of 1. It is has been found that the maximum oil extraction yield obtained from the chloroform (6.73 % and Acetone (4.37 % is much lower than that predicted by n-hexane 37.03 %.

  16. Conditional stability versus ill-posedness for operator equations with monotone operators in Hilbert space

    Science.gov (United States)

    Ioan Boţ, Radu; Hofmann, Bernd

    2016-12-01

    In the literature on singular perturbation (Lavrentiev regularization) for the stable approximate solution of operator equations with monotone operators in the Hilbert space the phenomena of conditional stability and local well-posedness or ill-posedness are rarely investigated. Our goal is to present some studies which try to bridge this gap. So we present new results on the impact of conditional stability on error estimates and convergence rates for the Lavrentiev regularization and distinguish for linear problems well-posedness and ill-posedness in a specific manner motivated by a saturation result. Taking into account that the behavior of the bias (regularization error in the noise-free case) is crucial, general convergence rates, including logarithmic rates, are derived for linear operator equations by means of the method of approximate source conditions. This allows us to extend well-known convergence rate results for the Lavrentiev regularization that were based on general source conditions to the case of non-selfadjoint linear monotone forward operators for which general source conditions fail. Examples presenting the self-adjoint multiplication operator as well as the non-selfadjoint fractional integral operator and Cesàro operator illustrate the theoretical results. Extensions to the nonlinear case under specific conditions on the nonlinearity structure complete the paper.

  17. VERIFICATION OF GEAR DYNAMIC MODEL IN DIFFERENT OPERATING CONDITIONS

    Directory of Open Access Journals (Sweden)

    Grzegorz PERUŃ

    2014-09-01

    Full Text Available The article presents the results of verification of the drive system dynamic model with gear. Tests were carried out on the real object in different operating conditions. For the same assumed conditions were also carried out simulation studies. Comparison of the results obtained from those two series of tests helped determine the suitability of the model and verify the possibility of replacing experimental research by simulations with use of dynamic model.

  18. Study on optimum growth condition and designing formulation for increasing shelf life of Streptomyces rimosus strain C-2012 as biocontrol agent

    Directory of Open Access Journals (Sweden)

    Ebrahim Karimi

    2015-12-01

    Full Text Available Introduction: An important issue in microbial biotechnology is linkage between screened beneficial strains in laboratory and industry. Therefore, to develop beneficial microbial biocontrol agents; optimization of nutritional and physiological condition for high level production and selection of carrier for final formulation are necessary. In this research we tried to find the best growth condition and suitable formulation for biocontrol Streptomyces rimosus strain C-2012. Materials and methods: For optimization of growth condition of strain C-2012, utilization of carbon sources, growth in different media, effect of temperature, pH and NaCl were investigated. Then the effect of different carriers and additives in final formulation and shelf life of microbial community were studied. Results: Study on utilization of carbon sources showed that glucose, fructose and mannitole were suitable carbon sources for growth and the best initial pH and temperature were 7 and 28°C, respectively. Results showed that the culture medium containing glucose, yeast extract and malt extract was the best medium. Investigation on NaCl effect showed that from 0 up to 300 mM sodium chloride could increase microbial community and salinity more than this range decreased microbial community. Based on the results we found that sand is suitable as microbial carrier comparing hydrogel polymers. Viability test during 36 months showed that formulation with NaCl content could keep 200 times (8*106 cfu/g more than samples without salinity at last month. Discussion and conclusion: Using suitable carbon sources such as glucose at 28 °C and pH at 7 are important items in optimum growth and preparing final formulation with good level of microbial community. Capability in secondary volatile and liquid metabolites production and fungal pathogen control by Streptomyces rimosus in the presence of NaCl showed that this strain has high potentiality to apply in both normal and saline area

  19. Risk management of exposure to chemicals under operational conditions

    NARCIS (Netherlands)

    Langenberg, J.P.

    2007-01-01

    The HFM panel has decided to install an Exploratory Team, ET-078, which should advise whether or not a Technical Group (TG) should be established on the subject of risk management of exposure to chemicals under operational conditions. This paper described the context and approach of ET-078.

  20. A Problem-Solving Approach to Teaching Operant Conditioning

    Science.gov (United States)

    Shields, Carolyn; Gredler, Margaret

    2003-01-01

    Psychology students frequently have misconceptions of basic concepts in operant conditioning. Prior classroom observations revealed that most students defined positive reinforcement as reward and equated negative reinforcement and punishment. Students also labeled positive reinforcement as rewarding good behavior and negative reinforcement as…

  1. Spontaneous decisions and operant conditioning in fruit flies.

    Science.gov (United States)

    Brembs, Björn

    2011-05-01

    Already in the 1930s Skinner, Konorski and colleagues debated the commonalities, differences and interactions among the processes underlying what was then known as "conditioned reflexes type I and II", but which is today more well-known as classical (Pavlovian) and operant (instrumental) conditioning. Subsequent decades of research have confirmed that the interactions between the various learning systems engaged during operant conditioning are complex and difficult to disentangle. Today, modern neurobiological tools allow us to dissect the biological processes underlying operant conditioning and study their interactions. These processes include initiating spontaneous behavioral variability, world-learning and self-learning. The data suggest that behavioral variability is generated actively by the brain, rather than as a by-product of a complex, noisy input-output system. The function of this variability, in part, is to detect how the environment responds to such actions. World-learning denotes the biological process by which value is assigned to environmental stimuli. Self-learning is the biological process which assigns value to a specific action or movement. In an operant learning situation using visual stimuli for flies, world-learning inhibits self-learning via a prominent neuropil region, the mushroom-bodies. Only extended training can overcome this inhibition and lead to habit formation by engaging the self-learning mechanism. Self-learning transforms spontaneous, flexible actions into stereotyped, habitual responses.

  2. A minicomputer interface for realtime operations: an application to operant conditioning.

    Science.gov (United States)

    Mayor, S J; Wilson, J

    1975-09-01

    A PDP-12 interface was designed, constructed, and tested for realtime imput and output of binary information. Within limits this interface can be used with any peripheral device which operates in the binary mode. In addition to its generality of application the interface features include ease of expansion and low cost. A description of its design and operation is give here is terms of a typical application: the control of behavioral equipment (i.e. "Skinner Boxes") for operant conditioning.

  3. Mathematical modelling of unglazed solar collectors under extreme operating conditions

    DEFF Research Database (Denmark)

    Bunea, M.; Perers, Bengt; Eicher, S.

    2015-01-01

    average temperature levels at the evaporator. Simulation of these systems requires a collector model that can take into account operation at very low temperatures (below freezing) and under various weather conditions, particularly operation without solar irradiation.A solar collector mathematical model......Combined heat pumps and solar collectors got a renewed interest on the heating system market worldwide. Connected to the heat pump evaporator, unglazed solar collectors can considerably increase their efficiency, but they also raise the coefficient of performance of the heat pump with higher...... was found due to the condensation phenomenon and up to 40% due to frost under no solar irradiation. This work also points out the influence of the operating conditions on the collector's characteristics.Based on experiments carried out at a test facility, every heat flux on the absorber was separately...

  4. Substantiation of optimum fill rate of the groups according to the sanitary and hygienic conditions of preschool educational institutions and risks of violations of children's health

    Directory of Open Access Journals (Sweden)

    V.N. Rakitskiy

    2016-09-01

    Full Text Available The increase in the number of children in groups of preschool educational institutions (PEI of more than 22 people is accompanied by a deterioration of sanitary and hygienic state of the premises of group cells by chemical, biological and physical indicators. In the densely populated groups the content of phenol and formaldehyde in the air of playing and sleeping rooms reaches 2.2–4.6 MAC daily average, for 30 % increases the air contamination by the conditionally pathogenic flora (St. aureus, the level of noise impact during gaming sessions is up to 80 dBA. Direct dependence between the increase of morbidity of children by the allergic diseases of the respiratory organs and the skin, functional gastrointestinal disorders, acute viral and bacterial diseases and urinary tract infections with the index of fill rate of PEI groups (R 2 = 0,32–0,89; r≤0,035–0,0001 has been correlated. The risk of violations of physical development and development delay of biological maturation of children is increased by more than 1.5–2.0 times (OR = 1,51–2,17; DI = 1,1–3,01; p = 0.01–0.03 and reduce of the adaptive reserve of the cardiovascular, respiratory and autonomic nervous system and the development of functional disorders, including cognitive, increases in 1,2–10,0 times (OR = 1,2–10,11; DI = 1,11–18,81; p = 0.01–0.04. Longtime combined effects of chemical, biological and physical factors determine the formation of chronic physiological distress syndrome in children, manifesting by a change in metabolism, haematopoiesis, decreased cellular activity and humoral immune response, a violation of the intracellular mechanisms of antioxidant protection (p = 0,0001–0,017. The results of sanitaryhygienic, clinical laboratory and mathematical methods of research have established that the optimum fill rate of groups of standard PEIs of general developmental orientation should not exceed 14–16 children and the standard of playing or sleeping

  5. Solid oxide fuel cell performance under severe operating conditions

    DEFF Research Database (Denmark)

    Koch, Søren; Hendriksen, P.V.; Mogensen, Mogens Bjerg

    2006-01-01

    The performance and degradation of Solid Oxide Fuel Cells (SOFC) were studied under severe operating conditions. The cells studied were manufactured in a small series by ECN, in the framework of the EU funded CORE-SOFC project. The cells were of the anode-supported type with a double layer LSM...... cathode. They were operated at 750 °C or 850 °C in hydrogen with 5% or 50% water at current densities ranging from 0.25 A cm–2 to 1 A cm–2 for periods of 300 hours or more. The area specific cell resistance, corrected for fuel utilisation, ranged between 0.20 Ω cm2 and 0.34 Ω cm2 at 850 °C and 520 m......V, and between 0.51 Ω cm2 and 0.92 Ω cm2 at 750 °C and 520 mV. The degradation of cell performance was found to be low (ranging from 0 to 8%/1,000 hours) at regular operating conditions. Voltage degradation rates of 20 to 40%/1,000 hours were observed under severe operating conditions, depending on the test...

  6. Optimisation of Shift Reactor Operating Conditions to Maximise Hydrogen Production

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, J. M.; Marano, M.; Ruiz, E.

    2011-07-28

    This report compiles the results of the work conducted by CIEMAT for Task 6.5 Shift reaction of the FLEXGAS project Near Zero Emission Advanced Fluidized Bed Gasification, which has been carried out with financial support from the Research Fund for Coal and Steel, RFCR-CT-2007-00005. The activity of an iron-chromium-based catalyst for the water gas shift reaction is studied. Results about WGS experiments conducted by CIEMAT on laboratory scale under different operating conditions are presented. The influence on the activity of the catalyst of main operating parameters- temperature, pressure, excess steam, and space velocity and gas composition - is evaluated and discussed. (Author) 19 refs.

  7. Marine Vessel Models in Changing Operational Conditions - A Tutorial

    DEFF Research Database (Denmark)

    Perez, Tristan; Sørensen, Asgeir; Blanke, Mogens

    2006-01-01

    conditions (VOC). However, since marine systems operate in changing VOCs, there is a need to adapt the models. To date, there is no theory available to describe a general model valid across different VOCs due to the complexity of the hydrodynamic involved. It is believed that system identification could......This tutorial paper provides an introduction, from a systems perspective, to the topic of ship motion dynamics of surface ships. It presents a classification of parametric models currently used for monitoring and control of marine vessels. These models are valid for certain vessel operational...

  8. Measurement of Lubricating Condition between Swashplate and Shoe in Swashplate Compressors under Practical Operating Conditions

    Science.gov (United States)

    Suzuki, Hisashi; Fukuta, Mitsuhiro; Yanagisawa, Tadashi

    In this paper, lubricating conditions between a swashplate and a shoe in a swashplate compressor for automotive air conditioners is investigated experimentally. The conditions are measured with an electric resistance method that utilizes the swash plate and the shoe as electrodes respectively. The instrumented compressor is connected to an experimental cycle with R134a and operated under various operating conditions of pressure and rotational speed. An improved measurement technique and applying a solid contact ratio to the measurement results permit to measure the lubricating condition at high rotational speed (more than 8000 rpm) and to predic an occurrence of scuffing between the swashplate and the shoe, and therefore enables a detailed study of lubricating characteristics. It is shown by the measurement that the voltage of the contact signal decreases, which means better lubricating condition, with the decrease of the compression pressure and with the increase of the rotational speed from 1000 rpm through 5000 rpm. The lubricating condition tends to worsen at more than 5000 rpm. Furthermore, it is confirmed that the lubricating condition under transient operation is worse obviously as compared with that under steady-state operation.

  9. Dioxins from medical waste incineration: Normal operation and transient conditions.

    Science.gov (United States)

    Chen, Tong; Zhan, Ming-xiu; Yan, Mi; Fu, Jian-ying; Lu, Sheng-yong; Li, Xiao-dong; Yan, Jian-hua; Buekens, Alfons

    2015-07-01

    Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are key pollutants in waste incineration. At present, incinerator managers and official supervisors focus only on emissions evolving during steady-state operation. Yet, these emissions may considerably be raised during periods of poor combustion, plant shutdown, and especially when starting-up from cold. Until now there were no data on transient emissions from medical (or hospital) waste incineration (MWI). However, MWI is reputed to engender higher emissions than those from municipal solid waste incineration (MSWI). The emission levels in this study recorded for shutdown and start-up, however, were significantly higher: 483 ± 184 ng Nm(-3) (1.47 ± 0.17 ng I-TEQ Nm(-3)) for shutdown and 735 ng Nm(-3) (7.73 ng I-TEQ Nm(-3)) for start-up conditions, respectively. Thus, the average (I-TEQ) concentration during shutdown is 2.6 (3.8) times higher than the average concentration during normal operation, and the average (I-TEQ) concentration during start-up is 4.0 (almost 20) times higher. So monitoring should cover the entire incineration cycle, including start-up, operation and shutdown, rather than optimised operation only. This suggestion is important for medical waste incinerators, as these facilities frequently start up and shut down, because of their small size, or of lacking waste supply. Forthcoming operation should shift towards much longer operating cycles, i.e., a single weekly start-up and shutdown.

  10. Optimum structural properties for an anode current collector used in a polymer electrolyte membrane water electrolyzer operated at the boiling point of water

    Science.gov (United States)

    Li, Hua; Fujigaya, Tsuyohiko; Nakajima, Hironori; Inada, Akiko; Ito, Kohei

    2016-11-01

    This study attempts to optimize the properties of the anode current collector of a polymer electrolyte membrane water electrolyzer at high temperatures, particularly at the boiling point of water. Different titanium meshes (4 commercial ones and 4 modified ones) with various properties are experimentally examined by operating a cell with each mesh under different conditions. The average pore diameter, thickness, and contact angle of the anode current collector are controlled in the ranges of 10-35 μm, 0.2-0.3 mm, and 0-120°, respectively. These results showed that increasing the temperature from the conventional temperature of 80 °C to the boiling point could reduce both the open circuit voltage and the overvoltages to a large extent without notable dehydration of the membrane. These results also showed that decreasing the contact angle and the thickness suppresses the electrolysis overvoltage largely by decreasing the concentration overvoltage. The effect of the average pore diameter was not evident until the temperature reached the boiling point. Using operating conditions of 100 °C and 2 A/cm2, the electrolysis voltage is minimized to 1.69 V with a hydrophilic titanium mesh with an average pore diameter of 21 μm and a thickness of 0.2 mm.

  11. Operation of static series compensator under distorted utility conditions

    DEFF Research Database (Denmark)

    Awad, H.; Nelsen, H.; Blaabjerg, Frede

    2005-01-01

    in the case of distorted grid voltage. Furthermore, a selective harmonic compensation strategy is applied to filter out the grid harmonics. The operation of the SSC under distorted utility conditions and voltage dips is discussed. The validity of the proposed controller is verified by experiments, carried out...... on a 10-kV SSC laboratory setup. Experimental results have shown the ability of the SSC to mitigate voltage dips and harmonics. It is also shown that the proposed controller has improved the transient performance of the SSC even under distorted utility conditions....

  12. ANALYSIS OF OPERATING INSTRUMENT LANDING SYSTEM ACCURACY UNDER SIMULATED CONDITIONS

    Directory of Open Access Journals (Sweden)

    Jerzy MERKISZ

    2017-03-01

    Full Text Available The instrument landing system (ILS is the most popular landing aid in the world. It is a distance-angled support system for landing in reduced visibility, while its task is the safe conduct of the aircraft from the prescribed course landing on the approach path. The aim of this study is to analyse the correctness of the ILS in simulated conditions. The study was conducted using a CKAS MotionSim5 flight simulator in the Simulation Research Laboratory of the Institute of Combustion Engines and Transport at Poznan University of Technology. With the advancement of technical equipment, it was possible to check the operation of the system in various weather conditions. Studies have shown that the impact of fog, rain and snow on the correct operation of the system is marginal. Significant influence has been observed, however, during landing in strong winds.

  13. How operant conditioning can contribute to behavioral toxicology

    Energy Technology Data Exchange (ETDEWEB)

    Laties, V.G.

    1978-10-01

    Operant conditioning can contribute to the development of behavioral toxicology in many ways. Its techniques are useful in training animals in the various behaviors the toxicologist may wish to study. They make possible the sophisticated assessment of sensory functioning. Operant conditioners excel at using schedules of intermittent reinforcement to create the type of stable animal performance needed in studying substances that produce effects only after prolonged exposure. Schedule-controlled behavior also helps elucidate the precise behavioral mechanisms involved in toxicity. In the early assessment of toxic substances a judiciously chosen sample of schedule-controlled performances may provide the best estimate whether the integrity of complex operant behavior remains unchanged. The development of improved behavioral techniques and computer technology promises to bring down the cost of such assessment.

  14. Operating Conditions Effects Onenzyme Activity: Case Enzyme Protease

    Directory of Open Access Journals (Sweden)

    Adel Oueslati

    2014-09-01

    Full Text Available The Proteases an enzyme added to detergents to degrade the protein spots origin.Their action is manifested through its activity the middle of washing clothes. This activity depends on the operating conditions. In this article, the effects of temperature and pH of the reaction and the substrate concentration and time of washing medium on the enzyme activity were studied. There action mechanism has been shown. The activity measurements were made by absorption spectrometry

  15. The Other Shoe: An Early Operant Conditioning Chamber for Pigeons

    OpenAIRE

    Sakagami, Takayuki; Lattal, Kennon A.

    2016-01-01

    We describe an early operant conditioning chamber fabricated by Harvard University instrument maker Ralph Gerbrands and shipped to Japan in 1952 in response to a request of Professor B. F. Skinner by Japanese psychologists. It is a rare example, perhaps the earliest still physically existing, of such a chamber for use with pigeons. Although the overall structure and many of the components are similar to contemporary pigeon chambers, several differences are noted and contrasted to evolutionary...

  16. Automated Operant Conditioning in the Mouse Home Cage

    Science.gov (United States)

    Francis, Nikolas A.; Kanold, Patrick O.

    2017-01-01

    Recent advances in neuroimaging and genetics have made mice an advantageous animal model for studying the neurophysiology of sensation, cognition, and locomotion. A key benefit of mice is that they provide a large population of test subjects for behavioral screening. Reflex-based assays of hearing in mice, such as the widely used acoustic startle response, are less accurate than operant conditioning in measuring auditory processing. To date, however, there are few cost-effective options for scalable operant conditioning systems. Here, we describe a new system for automated operant conditioning, the Psibox. It is assembled from low cost parts, designed to fit within typical commercial wire-top cages, and allows large numbers of mice to train independently in their home cages on positive reinforcement tasks. We found that groups of mice trained together learned to accurately detect sounds within 2 weeks of training. In addition, individual mice isolated from groups also showed good task performance. The Psibox facilitates high-throughput testing of sensory, motor, and cognitive skills in mice, and provides a readily available animal population for studies ranging from experience-dependent neural plasticity to rodent models of mental disorders. PMID:28298887

  17. Fischer-Tropsch Synthesis over Iron Manganese Catalysts: Effect of Preparation and Operating Conditions on Catalyst Performance

    Directory of Open Access Journals (Sweden)

    Ali A. Mirzaei

    2009-01-01

    molar basis which is the most active catalyst for the conversion of synthesis gas to light olefins. The effects of different promoters and supports with loading of optimum support on the catalytic performance of catalysts are also studied. It was found that the catalyst containing 50%Fe/50%Mn/5 wt.%Al2O3 is an optimum-modified catalyst. The catalytic performance of optimal catalyst has been studied in operation conditions such as a range of reaction temperatures, H2/CO molar feed ratios and a range of total pressures. Characterization of both precursors and calcined catalysts is carried out by powder X-ray diffraction (XRD, scanning electron microscopy (SEM, BET specific surface area and thermal analysis methods such as TGA and DSC.

  18. Operational modal analysis of vehicle system based on SSI under operational conditions

    Science.gov (United States)

    Zhou, Suxia; Xie, Yunye; Xie, Jilong; Li, Fang

    2010-03-01

    The modal parameters of linear vehicle system are analyzed by the theoretical modal parameter analysis method first, and then SSI based on operational conditions is presented to form the estimation formula of modal parameters of linear vehicle system. At last, the modal parameters of linear vehicle system are identified by SSI after its vibration test under operational conditions, and are simultaneously compared to the results obtained by the theoretical modal parameter analysis method. Comparison results show discrepancies of 0.61~8.32 percent on modal frequencies and 3.86~11.61 percent on modal damping ratios, which implies that SSI based on the operational condition is feasible and effective, and has comparatively higher precision to meet the needs of engineering.

  19. The Effect of the Operating Conditions on the Apparent Viscosity of Crude Palm Oil During Oil Clarification

    Directory of Open Access Journals (Sweden)

    Sulaiman Al-Zuhair, Mirghani I. Ahmed and Yousif A. Abakr

    2012-10-01

    Full Text Available This paper discusses the apparent viscosity of crude palm oil, using rotary viscometer, under different boundary conditions. It was experimentally shown that the apparent viscosity of palm oil drops with increasing of the shear rate and the temperature.  However, the effect of temperature on the viscosity tends to fade at temperatures beyond 80 oC.  A correlation between the apparent viscosity of crude palm oil and the operating conditions was developed. This correlation can be used in design of crude palm oil settlers and in determining the optimum operating conditions.Key Words:  Crude palm oil, apparent viscosity, shear rate, modelling, separation 

  20. Effect of operative conditions on a PEFC stack performance

    Energy Technology Data Exchange (ETDEWEB)

    Urbani, Francesco; Barbera, Orazio; Giacoppo, Giosue; Squadrito, Gaetano; Passalacqua, Enza [CNR-ITAE (Istituto di Tecnologie Avanzate per l' Energia ' Nicola Giordano' ), Salita S. Lucia sopra Contesse, 5-98126 Messina (Italy)

    2008-06-15

    The operative conditions influence the performance of a polymer electrolyte fuel cell (PEFC). In particular, when a multi-cell (stack) instead of a single cell is investigated, a proper water management and flow stoichiometric ratio are essential for obtaining high electrical conversion efficiency. In this paper, a five cell air cooled PEM fuel cell stack was designed and realized, and systematic studies on the influence of the reactants humidification have been carried out to optimize the operative conditions. Polarization curves and time test at a fixed current have been conducted for various cathode (RHC) and anode (RHA) inlet humidity conditions. In particular, a small decay and low performance were obtained for RHA and <70% and a considerable decay and low performance for RHA and >70%. A good compromise for water management, in terms of decay and performance, is obtained when a symmetrical RH of 70% was used, because in this case an optimal water balance was probably reached considering that high flow of gases was used. In fact, insufficient water content implies a lower ion conductivity of the membrane whereas excess of water yields to flooding of the electrodes and parasitic losses due to the presence of water in the gas channels. Consequently, these effects lead to a lowering of voltages during lifetime tests. In any case, the cathode RH has a stronger influence on the stack decay compared to the anode one. In the optimal selected conditions of RH a constant and stable power of about 55 W (at 20 A) was obtained during the 15 h of operation. (author)

  1. The Optimum Growth Rate for Population Reconsidered

    OpenAIRE

    Jaeger, Klaus; Kuhle, Wolfgang

    2007-01-01

    This article gives exact general conditions for the existence of an interior optimum growth rate for population in the neoclassical two-generations-overlapping model. In an economy where high (low) growth rates of population lead to a growth path which is efficient (inefficient) there always exists an interior optimum growth rate for population. In all other cases there exists no interior optimum. The Serendipity Theorem, however, does in general not hold in an economy with government debt. M...

  2. The Operator's Diagnosis Task under Abnormal Operating Conditions in Industrial Process Plant

    DEFF Research Database (Denmark)

    Goodstein, L.P.; Pedersen, O.M.; Rasmussen, Jens

    1974-01-01

    Analysis of serious accidents in connection with the operation of technical installations demonstrate that the diagnosis task which confronts personnel under non-normal plant conditions is a critical one. This report presents a preliminary outline of characteristic traits connected with the task...

  3. Flux behaviour under different operational conditions in osmosis process

    DEFF Research Database (Denmark)

    Korenak, Jasmina; Zarebska, Agata; Buksek, Hermina;

    the active membrane layer is facing draw solution. Osmosis process can be affected by several factors, such as operating conditions (temperature and cross flow velocity), feed and draw solution properties, and membrane characteristics. These factors can significantly contribute to the efficiency...... of the process itself. In order to implement the osmosis process on an industrial scale, process economy need to be taken into consideration, as well as the desired final product quality. Membrane performance can be evaluated based on the water permeability and the selectivity of the membrane. The permeability...

  4. The Other Shoe: An Early Operant Conditioning Chamber for Pigeons.

    Science.gov (United States)

    Sakagami, Takayuki; Lattal, Kennon A

    2016-05-01

    We describe an early operant conditioning chamber fabricated by Harvard University instrument maker Ralph Gerbrands and shipped to Japan in 1952 in response to a request of Professor B. F. Skinner by Japanese psychologists. It is a rare example, perhaps the earliest still physically existing, of such a chamber for use with pigeons. Although the overall structure and many of the components are similar to contemporary pigeon chambers, several differences are noted and contrasted to evolutionary changes in this most important laboratory tool in the experimental analysis of behavior. The chamber also is testimony to the early internationalization of behavior analysis.

  5. Optimal line drop compensation parameters under multi-operating conditions

    Science.gov (United States)

    Wan, Yuan; Li, Hang; Wang, Kai; He, Zhe

    2017-01-01

    Line Drop Compensation (LDC) is a main function of Reactive Current Compensation (RCC) which is developed to improve voltage stability. While LDC has benefit to voltage, it may deteriorate the small-disturbance rotor angle stability of power system. In present paper, an intelligent algorithm which is combined by Genetic Algorithm (GA) and Backpropagation Neural Network (BPNN) is proposed to optimize parameters of LDC. The objective function proposed in present paper takes consideration of voltage deviation and power system oscillation minimal damping ratio under multi-operating conditions. A simulation based on middle area of Jiangxi province power system is used to demonstrate the intelligent algorithm. The optimization result shows that coordinate optimized parameters can meet the multioperating conditions requirement and improve voltage stability as much as possible while guaranteeing enough damping ratio.

  6. An Optimum Currency Crisis

    Directory of Open Access Journals (Sweden)

    Paolo Pasimeni

    2014-12-01

    Full Text Available This paper presents an ex-post assessment of the current situation of the EMU in light of the conditions prescribed by the theory of Optimum Currency Areas (OCA. The analysis shows that some of those conditions were satisfied at the inception of the EMU, others were missing at the beginning, but improved over time as expected by the endogenous approach to the OCA theory. The common fiscal capacity was the main missing element of the initial construction of the Eurozone, and still is. The common budget is so exiguous that its effectiveness as shock absorption mechanism is negligible. The analysis then shows how some of the concerns raised on the eve of the euro did actually materialize, even if not immediately. First, in its first decade the Eurozone did not experience major turbulences, because growing financial integration was compensating the need for fiscal transfers, channelling the excess of saving from the ‘core’ to the ‘periphery’. Second, the mechanism generated record-high private indebtedness in the ‘periphery’ and exposure of the banks in the ‘core’, making the whole system more fragile as it relied upon financial markets’ stability. Third, once the long-feared shock hit, the mechanism proved weak and non-resilient. The inherent weaknesses of the EMU became evident. Fourth, as it had been foreseen, the cost of the adjustment after the shock fell mainly on labour, with much higher and longer unemployment in the Eurozone than both non-Eurozone EU and the US. Fifth, as the theory suggested, the lack of common mechanisms of adjustment dramatically increased the socio-economic divergences within the EMU. The paper finally presents a simulation for a common budget of the Eurozone, linked to the relative current account positions of the member states.

  7. Moderate induced hypotension provides satisfactory operating conditions in maxillofacial surgery.

    Science.gov (United States)

    Schindler, I; Andel, H; Leber, J; Kimla, T

    1994-05-01

    Patients scheduled for maxillofacial surgery were randomly assigned to receive isoflurane (n = 22) or nitroglycerin (n = 18) in order to induce hypotension. Surgeons, blinded for the actual level of blood pressure and the technique used for inducing hypotension, were asked to rate operating conditions on a scale from 1 to 5. Systolic arterial pressure (SAP) and mean arterial pressure (MAP) were reduced by 26% for both groups. Although blood pressure levels showed little variation throughout the induced hypotension period, scores of 2 to 5 were given significantly more often at incision and at 30 min compared to the following measuring points (P < 0.01). In total, the surgical field was rated significantly more often with a score of 1 and 2 than with a score of 3 to 5 (P < 0.01). A relation between score and SAP and/or MAP could not be found. There was also no relation between scores and the technique used for hypotension. Our data suggest that, with the exception of the first half hour of surgery, on average a SAP of 89 mmHg and a MAP of 65 mmHg were sufficient to produce satisfactory operating conditions.

  8. Quantifying Social Motivation in Mice Using Operant Conditioning.

    Science.gov (United States)

    Martin, Loren; Iceberg, Erica

    2015-08-08

    In this protocol, social motivation is measured in mice through a pair of operant conditioning paradigms. To conduct the experiments, two-chambered shuttle boxes were equipped with two operant levers (left and right) and a food receptacle in one chamber, which was then divided from the second chamber by an automated guillotine door covered by a wire grid. Different stimulus mice, rotated across testing days, served as a social stimulus behind the wire grid, and were only visible following the opening of the guillotine door. Test mice were trained to lever press in order to open the door and gain access to the stimulus partner for 15 sec. The number of lever presses required to obtain the social reward progressively increased on a fixed schedule of 3. Testing sessions ended after test mice stopped lever pressing for 5 consecutive minutes. The last reinforced ratio or breakpoint can be used as a quantitative measure of social motivation. For the second paradigm, test mice were trained to discriminate between left and right lever presses in order to obtain either a food reward or the social reward. Mice were rewarded for every 3 presses of each respective lever. The number of food and social rewards can be compared as a measurement of the value placed upon each reward. The ratio of each reward type can also be compared between mouse strains and the change in this ratio can be monitored within testing sessions to measure satiation with a given reward type. Both of these operant conditioning paradigms are highly useful for the quantification of social motivation in mouse models of autism and other disorders of social behavior.

  9. 比色法测定微量尿素最佳条件的探究%Study on the Optimum Condition by Colorimetry

    Institute of Scientific and Technical Information of China (English)

    郎德龙

    2016-01-01

    我国是农业大国,尿素的使用量极大,但是也造成了土壤与水质等方面的污染。溶液中尿素含量在1%以上,用对二甲氨基苯甲醛比色法测定时,能够准确、快捷、操作简便。但当对二甲氨基苯甲醛比色法在测定水中微量尿素时,方法重现性较差。为了有效监控生产和确保回收水质的合格率,以及控制今后的分析数据在误差允许的范围内,将对二甲氨基苯甲醛比色法进行适当改进,可大大提高该方法的灵敏度和准确度。%China is a large agricultural country, a great amount of urea are used, it causes soil and water quality pollutions. When urea content is above 1%, the using of dimethylamino-benzaldehyde method is more accurate, quick, simple operation. dimethylamino-benzaldehyde colorimetry in the determination of trace urea of reproducibility is poor, sample recovery rate is low, not conducive to guide the production process. In order to effectively monitor the production, and ensure the quality of the qualified rate of recovery and control the future of the analysis of the data in the error within the allowable range, dimethyl-amino-benzaldehyde colorimetry was improved properly, it can greatly improve the sensitivity and accuracy. The method of optimal conditions was studied through the different conditions of dimethylamino-benzaldehyde colorimetry.

  10. Simulation of gas turbines operating in off-design condition

    Energy Technology Data Exchange (ETDEWEB)

    Walter, Arnaldo [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Mecanica. Dept. de Energia]. E-mail: walter@fem.unicamp.br

    2000-07-01

    In many countries thermal power plants based on gas turbines have been the main option for new investment into the electric system due to their relatively high efficiency and low capital cost. Cogeneration systems based on gas turbines have also been an important option for the electric industry. Feasibility studies of power plants based on gas turbine should consider the effect of atmospheric conditions and part-load operation on the machine performance. Doing this, an off-design procedure is required. A G T off-design simulation procedure is described in this paper. Ruston R M was used to validate the simulation procedure that, general sense, presents deviations lower than 2.5% in comparison to manufacturer's data. (author)

  11. Effect of Operating Conditions on CSTR performance: an Experimental Study

    Directory of Open Access Journals (Sweden)

    Mohd Danish

    2015-02-01

    Full Text Available In this work, Saponification reaction of ethyl acetate by sodium hydroxide is studied experimentally in a continuous stirred tank reactor at 1 atmospheric pressure. The aim of this study is to investigate the influence of operating conditions on the conversion and specific rate constant. The parameters considered for analysis are temperature, feed flow rate, residence time, volume of reactor and stirrer rate. The steady state conversion of 0.45 achieved after a period of 30 minutes. Conversion decreases with increase of reactant flow rate due to decrease of residence time. The stirrer rate has a positive effect on the conversion and rate constant. Specific rate constant and conversion increase with temperature within the studied temperature range. Within the range of reactor volume selected for analysis, conversion increases with increase in reactor volume. The results obtained in this study may be helpful in maximizing the conversion of ethyl acetate saponification reaction at industrial scale in a CSTR.

  12. Effects of Operational Conditions on the Performance of Triethylamine Biofiltration

    Directory of Open Access Journals (Sweden)

    A Torkian, H Keshavarzi Shirazi, A Azimi

    2005-04-01

    Full Text Available Nitrogen compounds such as triethylamine are odorants generally found in chemical plants and foundries in which cold-box cores are made. In this study, the efficiency of biofiltration of triethylamine (TEA vapor was evaluated. Experiments were conducted in two 6-L biofilters arranged in three stages and packed with inoculated compost - wood chips (40:60v/v as the filter medium. The seed inoculum was obtained from municipal activated sludge. Tests were made to compare effects of initial temperature (30±1°C, biofilter A and (23±2 °C, biofilter B on the performance of the biofilter. TEA elimination rate pattern was evaluated by changing loading rates (6-138 gm-3h-1 and hydraulic retention times (40-60 s while operating at constant temperature and humidity at 50-55%. Results showed that organic loading rates (OLR of up to 114.4 gm-3h-1 (biofilter A and 90.56 gm-3h-1 (biofilter B could be handled without any apparent indication of maximum elimination capacity and substrate inhibition. The elimination capacity of biofilters could reach up to 72 gm-3h-1 (biofilter A and 61.5 gm-3h-1(biofilter B. When the loading of TEA exceeded the critical values, substrate inhibition occurred and the elimination capacity decreased. However, the requirement of keeping the pressure drop below 4 cm water gauge per meter of bed height to avoid operational problems warranted lower than maximum capacity operation. The optimal OLR values of 90±14 gm-3h-1 are suggested for hydraulic retention time value of 48 s and temperature of 30±1°C. Under these conditions, elimination capacity of 71±3 gm-3h-1and removal efficiency of 81±14% was achieved.

  13. Wealth Financialization: Operating Profit as Conditioning of Financial Revenue

    Directory of Open Access Journals (Sweden)

    Andréia Ribeiro Da Luz

    2015-04-01

    Full Text Available Objective. Due to the deregulation of the financial market in 80s decade, the financialization of wealth has become a globalized systemic pattern, giving companies greater access to financial innovations. In view of the above, the objective is to analyze whether the appreciation of capital through the financial system is preferred over the capital appreciation through production.Methodology. This is a descriptive research slitting with cross-sectional perspective, in which we considered information belonging to 106 listed non-financial companies in Brazil (2004–2012.Findings. This study suggests that operating income influences financial income positively.Limitations. The study includes just industrial sector companies in a specific period.Originality/Value. We discuss measuring instruments for analyzing the wealth financialization as a condition of operating profit gains from the financial market.Copyright © 2015 Instituto Brasileiro de Inovação Financeira All rights reserved.

  14. Optimization of Design Parameters and Operating Conditions of Electrochemical Capacitors for High Energy and Power Performance

    Science.gov (United States)

    Ike, Innocent S.; Sigalas, Iakovos; Iyuke, Sunny E.

    2017-03-01

    Theoretical expressions for performance parameters of different electrochemical capacitors (ECs) have been optimized by solving them using MATLAB scripts as well as via the MATLAB R2014a optimization toolbox. The performance of the different kinds of ECs under given conditions was compared using theoretical equations and simulations of various models based on the conditions of device components, using optimal values for the coefficient associated with the battery-kind material ( K BMopt) and the constant associated with the electrolyte material ( K Eopt), as well as our symmetric electric double-layer capacitor (EDLC) experimental data. Estimation of performance parameters was possible based on values for the mass ratio of electrodes, operating potential range ratio, and specific capacitance of electrolyte. The performance of asymmetric ECs with suitable electrode mass and operating potential range ratios using aqueous or organic electrolyte at appropriate operating potential range and specific capacitance was 2.2 and 5.56 times greater, respectively, than for the symmetric EDLC and asymmetric EC using the same aqueous electrolyte, respectively. This enhancement was accompanied by reduced cell mass and volume. Also, the storable and deliverable energies of the asymmetric EC with suitable electrode mass and operating potential range ratios using the proper organic electrolyte were 12.9 times greater than those of the symmetric EDLC using aqueous electrolyte, again with reduced cell mass and volume. The storable energy, energy density, and power density of the asymmetric EDLC with suitable electrode mass and operating potential range ratios using the proper organic electrolyte were 5.56 times higher than for a similar symmetric EDLC using aqueous electrolyte, with cell mass and volume reduced by a factor of 1.77. Also, the asymmetric EDLC with the same type of electrode and suitable electrode mass ratio, working potential range ratio, and proper organic electrolyte

  15. Experimental investigation of an optimum configuration for a high-voltage photoemission gun for operation at ≥500 kV

    Science.gov (United States)

    Nishimori, Nobuyuki; Nagai, Ryoji; Matsuba, Shunya; Hajima, Ryoichi; Yamamoto, Masahiro; Honda, Yosuke; Miyajima, Tsukasa; Iijima, Hokuto; Kuriki, Masao; Kuwahara, Makoto

    2014-05-01

    We demonstrated the generation of a 500-keV electron beam from a high dc voltage photoemission gun for an energy recovery linac light source [N. Nishimori et al., Appl. Phys. Lett. 102, 234103 (2013)]. This demonstration was achieved by addressing two discharge problems that lead to vacuum breakdown in the dc gun. One is field emission generated from a central stem electrode. We employed a segmented insulator to protect the ceramic insulator surface from the field emission. The other is microdischarge at an anode electrode or a vacuum chamber, which is triggered by microparticle transfer or field emission from a cathode electrode. An experimental investigation revealed that a larger acceleration gap, optimized mainly to reduce the surface electric field of the anode electrode, suppresses the microdischarge events that accompany gas desorption. It was also found that nonevaporable getter pumps placed around the acceleration gap greatly help to suppress those microdischarge events. The applied voltage as a function of the total gas desorption is shown to be a good measure for finding the optimum dc gun configuration.

  16. Effect of circadian phase on memory acquisition and recall: operant conditioning vs. classical conditioning.

    Directory of Open Access Journals (Sweden)

    Madeleine V Garren

    Full Text Available There have been several studies on the role of circadian clocks in the regulation of associative learning and memory processes in both vertebrate and invertebrate species. The results have been quite variable and at present it is unclear to what extent the variability observed reflects species differences or differences in methodology. Previous results have shown that following differential classical conditioning in the cockroach, Rhyparobia maderae, in an olfactory discrimination task, formation of the short-term and long-term memory is under strict circadian control. In contrast, there appeared to be no circadian regulation of the ability to recall established memories. In the present study, we show that following operant conditioning of the same species in a very similar olfactory discrimination task, there is no impact of the circadian system on either short-term or long-term memory formation. On the other hand, ability to recall established memories is strongly tied to the circadian phase of training. On the basis of these data and those previously reported for phylogenetically diverse species, it is suggested that there may be fundamental differences in the way the circadian system regulates learning and memory in classical and operant conditioning.

  17. MAXIMUM INFORMATION AND OPTIMUM ESTIMATING FUNCTION

    Institute of Scientific and Technical Information of China (English)

    林路

    2003-01-01

    In order to construct estimating functions in some parametric models, this paper introducestwo classes of information matrices. Some necessary and sufficient conditions for the informationmatrices achieving their upper bounds are given. For the problem of estimating the median,some optimum estimating functions based on the information matrices are acquired. Undersome regularity conditions, an approach to carrying out the best basis function is introduced. Innonlinear regression models, an optimum estimating function based on the information matricesis obtained. Some examples are given to illustrate the results. Finally, the concept of optimumestimating function and the methods of constructing optimum estimating function are developedin more general statistical models.

  18. The operating room: architectural conditions and potential hazards.

    Science.gov (United States)

    Koneczny, Sonja

    2009-01-01

    Ergonomics is still not fully implemented in the design of operation rooms (ORs). The OR staff has to deal with various ergonomic deficiencies which may be associated with potential hazards for the patient and/or the OR team.Three surveys were conducted among German OR staff at major conferences. Two of them dealt with the working conditions in the OR and were conducted among surgeons and OR nurses. The third survey queried OR nurses about the electrical safety in the OR.In addition, a specially developed checklist was used to evaluate the work place OR in five German OR units and the staff of these OR units were queried with questionnaires adapted from the surveys. For this article a few of the deficiencies found in the ORs were chosen to serve as examples for the plethora of results gathered.Findings showed that there was a high potential for ergonomic improvement and therefore an increase in safety and comfort. Many of these deficiencies may be eased by simple means such as the reduction of the number of different devices and mandatory training in the use of the devices since device operation is one of the main causes leading to potential hazards in the OR. Other deficiencies, such as the cable routing in the OR, require more extensive intervention and/or the implementation of new techniques, for example the "wireless" OR. All these deficiencies demonstrate the need for better implementation of ergonomics into the OR and for individual solutions, as there is no such thing as an 'one-size-fits-all' solution for OR units.

  19. Chemical imaging of Fischer-Tropsch catalysts under operating conditions

    Science.gov (United States)

    Price, Stephen W. T.; Martin, David J.; Parsons, Aaron D.; Sławiński, Wojciech A.; Vamvakeros, Antonios; Keylock, Stephen J.; Beale, Andrew M.; Mosselmans, J. Frederick W.

    2017-01-01

    Although we often understand empirically what constitutes an active catalyst, there is still much to be understood fundamentally about how catalytic performance is influenced by formulation. Catalysts are often designed to have a microstructure and nanostructure that can influence performance but that is rarely considered when correlating structure with function. Fischer-Tropsch synthesis (FTS) is a well-known and potentially sustainable technology for converting synthetic natural gas (“syngas”: CO + H2) into functional hydrocarbons, such as sulfur- and aromatic-free fuel and high-value wax products. FTS catalysts typically contain Co or Fe nanoparticles, which are often optimized in terms of size/composition for a particular catalytic performance. We use a novel, “multimodal” tomographic approach to studying active Co-based catalysts under operando conditions, revealing how a simple parameter, such as the order of addition of metal precursors and promoters, affects the spatial distribution of the elements as well as their physicochemical properties, that is, crystalline phase and crystallite size during catalyst activation and operation. We show in particular how the order of addition affects the crystallinity of the TiO2 anatase phase, which in turn leads to the formation of highly intergrown cubic close-packed/hexagonal close-packed Co nanoparticles that are very reactive, exhibiting high CO conversion. This work highlights the importance of operando microtomography to understand the evolution of chemical species and their spatial distribution before any concrete understanding of impact on catalytic performance can be realized. PMID:28345057

  20. Action Selection and Operant Conditioning: A Neurorobotic Implementation

    Directory of Open Access Journals (Sweden)

    André Cyr

    2015-01-01

    Full Text Available Action selection (AS is thought to represent the mechanism involved by natural agents when deciding what should be the next move or action. Is there a functional elementary core sustaining this cognitive process? Could we reproduce the mechanism with an artificial agent and more specifically in a neurorobotic paradigm? Unsupervised autonomous robots may require a decision-making skill to evolve in the real world and the bioinspired approach is the avenue explored through this paper. We propose simulating an AS process by using a small spiking neural network (SNN as the lower neural organisms, in order to control virtual and physical robots. We base our AS process on a simple central pattern generator (CPG, decision neurons, sensory neurons, and motor neurons as the main circuit components. As novelty, this study targets a specific operant conditioning (OC context which is relevant in an AS process; choices do influence future sensory feedback. Using a simple adaptive scenario, we show the complementarity interaction of both phenomena. We also suggest that this AS kernel could be a fast track model to efficiently design complex SNN which include a growing number of input stimuli and motor outputs. Our results demonstrate that merging AS and OC brings flexibility to the behavior in generic dynamical situations.

  1. Mobility and Cloud: Operating in Intermittent, Austere Network Conditions

    Science.gov (United States)

    2014-09-01

    35 viii 2. Piracy Interdiction Use Case.............................................................38 E...38 Figure 11. Operational view: Piracy interdiction operation. .............................................40...Storage Service SAR Search and Rescue SATCOM satellite communications SIPRNET Secret Internet Protocol Router Network SSAS Ship Security Alert System

  2. On the resolvent of multidimensional operators with frequently changing boundary conditions in the case of the homogenized Dirichlet condition

    Energy Technology Data Exchange (ETDEWEB)

    Sharapov, T F [Bashkir State Pedagogical University, Ufa (Russian Federation)

    2014-10-31

    We consider an elliptic operator in a multidimensional domain with frequently changing boundary conditions in the case when the homogenized operator contains the Dirichlet boundary condition. We prove the uniform resolvent convergence of the perturbed operator to the homogenized operator and obtain estimates for the rate of convergence. A complete asymptotic expansion is constructed for the resolvent when it acts on sufficiently smooth functions. Bibliography: 41 titles.

  3. 火力发电厂采暖空调系统余热利用优化设计%The Optimum Design of the Waste Heat Utilization of Heating&Air-conditioning System in Thermal Power Plant

    Institute of Scientific and Technical Information of China (English)

    费洪磊; 刘欢; 薛岑

    2015-01-01

    我国能源紧缺,一次能源及各种余热资源利用水平较低,深度挖掘利用电厂余热,制定合理的回收利用方案,优化设计采暖空调系统,提高电厂余热利用率十分重要. 基于电厂采暖空调系统余热利用存在的问题,详细介绍了火力发电厂采暖空调系统余热利用的优化设计.%Because of the energy shortage and a lower utilization level of primary energy and various waste heat resources utilization in China, the deep excavation and utilization of the waste heat in thermal power plant, the formulation of reasonable recycling scheme, the optimum design of heating & air-conditioning system and the improvement of utilization rate of waste heat are very important.Based on the problems existing in the waste heat utilization of heating&air-conditioning system in thermal power plant, this paper introduces in detail the optimum design of the waste heat utilization of heating&air-conditioning system in thermal power plant.

  4. Effect of membrane property and operating conditions on phytochemical properties and permeate flux during clarification of pineapple juice

    KAUST Repository

    Laorko, Aporn

    2010-10-01

    The effects of membrane property on the permeate flux, membrane fouling and quality of clarified pineapple juice were studied. Both microfiltration (membrane pore size of 0.1 and 0.2 μm) and ultrafiltration (membrane molecular weight cut-off (MWCO) of 30 and 100 kDa) membranes were employed. Membrane filtration did not have significant effects on the pH, reducing sugar and acidity of clarified juice whereas the suspended solids and microorganism were completely removed. The 0.2 μm membrane gave the highest permeate flux, total vitamin C content, total phenolic content and antioxidant capacity as well as the highest value of irreversible fouling. Based on these results, the membrane with pore size of 0.2 μm was considered to be the most suitable membrane for the clarification of pineapple juice. The optimum operating conditions for the clarification pineapple juice by membrane filtration was a cross-flow velocity of 3.4 ms-1 and transmembrane pressure (TMP) of 0.7 bar. An average flux of about 37 lm-2 h-1 was obtained during the microfiltration of pineapple juice under the optimum conditions using batch concentration mode. © 2010 Elsevier Ltd. All rights reserved.

  5. Optimum Conditions for the Efficacy and Safety of Cryofiltration Apheresis: An Analysis of Circuit Temperatures Depending on Plasma Flow Rate and Cooling Coil Lengths/Turns.

    Science.gov (United States)

    Nakajima, Hirofumi; Kaneko, Shuzo; Sato, Yukihiro; Takano, Tomoo; Hosino, Toshihisa

    2015-08-01

    A system providing both appropriate cooling and warming are needed for the efficacy and safety of cryofiltration (CF) plasmapheresis. We measured some points of CF circuit temperatures with varying plasma flow rates (QP  = 10-40 mL/min) and the numbers of connecting cooling coils (one or two) under the conditions of blood flow rate (QB ) 100 mL/min with 7700-mm coil length, 19 turns, and 50-mL priming volume. We measured the respective temperatures of each point of starting/returning for an extracorporeal circuit (TA /TV ), intracooling coil (TC ), and post-plasma fractionator (PF) (TPF ). The subtraction of TV from TA (ΔT) was used as an indicator of safe return. There were no significant differences in TC , TPF , or ΔT in accordance with each QP between that of one and two coils. All of the Tc values under the condition QP  ≤ 20 mL/min achieved <4°C. The TPF under the condition QP  ≥ 20 mL/min was not significantly different compared to that of QP 30 mL/min (the lowest condition). Although the ΔT increased depending on the QP increase, the ΔT under the condition QP  ≤ 15 mL/min was not significantly different from that of the control (one-way double-filtration plasmapheresis [DFPP]) group. We conclude that (i) one coil is enough for effective cooling in CF, and (ii) an ideal QP that fulfills the required conditions for both effective cooling and sufficient warming of returning fluid does not exist, but QP from 15 to 20 mL/min may be a relevant range.

  6. Carbon isotope ratio analysis of organic moieties from fossil mummified wood: establishing optimum conditions for off-line pyrolysis extraction using gas chromatography/mass spectrometry

    NARCIS (Netherlands)

    Poole, I.J.; Bergen, P.F. van

    2002-01-01

    Mummified fossil wood was studied using off-line pyrolysis-gas chromatography/mass spectrometry to reveal detailed insights into the pyrolysis conditions that are needed to obtain simultaneously sufficient amounts of both cellulose and lignin markers for stable carbon isotope analyses. The off-line

  7. Carbon isotope ratio analysis of organic moieties from fossil mummified wood: establishing optimum conditions for off-line pyrolysis extraction using gas chromatography/mass spectrometry

    NARCIS (Netherlands)

    Poole, I.J.; Bergen, P.F. van

    2002-01-01

    Mummified fossil wood was studied using off-line pyrolysis-gas chromatography/mass spectrometry to reveal detailed insights into the pyrolysis conditions that are needed to obtain simultaneously sufficient amounts of both cellulose and lignin markers for stable carbon isotope analyses. The off-line

  8. Optimum Conditions for Microwave Assisted Extraction for Recovery of Phenolic Compounds and Antioxidant Capacity from Macadamia (Macadamia tetraphylla Skin Waste Using Water

    Directory of Open Access Journals (Sweden)

    Adriana Dailey

    2015-12-01

    Full Text Available This study aimed to develop optimal microwave assisted extraction conditions for recovery of phenolic compounds and antioxidant properties from the macadamia skin, an abundant waste source from the macadamia industry. Water, a safe, accessible, and inexpensive solvent, was used as the extraction solvent and Response Surface Methodology (RSM was applied to design and analyse the conditions for microwave-assisted extraction (MAE. The results showed that RSM models were reliable for the prediction of extraction of phenolic compounds and antioxidant properties. Within the tested ranges, MAE radiation time and power, as well as the sample-to-solvent ratio, affected the extraction efficiency of phenolic compounds, flavonoids, proanthocyanidins, and antioxidant properties of the macadamia skin; however, the impact of these variables was varied. The optimal MAE conditions for maximum recovery of TPC, flavonoids, proanthocyanidins and antioxidant properties from the macadamia skin were MAE time of 4.5 min, power of 30% (360 W and sample-to-water ratio of 5 g/100 mL. Under these conditions, an extract could be prepared with TPC of 45 mg/g, flavonoids of 29 mg RUE/g of dried macadamia skin.

  9. Optimum condition of Bac-J23 production from Lactobacillus J23%Lactobacillus J23发酵合成抗茵肽Bac-J23培养条件的优化研究

    Institute of Scientific and Technical Information of China (English)

    易华西; 韩雪; 杜明; 张兰威

    2012-01-01

    pH, temperature and inoculation size dependent property were observed when Lactobacillus paracasei-J23 produced Bac-J23. The optimum condition to Bac-J23 synthesize were 36.8 ℃, pHS.2 and 2.13×10^4 cfu/mL inoculum size. Under the optimum condition, the production of Bac-J23 was improved 1.68 folds and reached 5400 U/mL.%研究了培养条件(接种量、发酵温度、初始pH)对Lactobacillus J23发酵合成广谱抗茵肽Bac-J23的影响,并采用响应面法进行了优化。结果表明,Lactobacillus-J23生产Bac-J23体现出温度、pH梯度和接种剂量依赖性,响应面优化结果表明最适温度和pH分别为36.8℃和5.2,接种量阈值为2.13×10^4cfu/mL。

  10. Effects of a Nano-Silica Additive on the Rock Erosion Characteristics of a SC-CO2 Jet under Various Operating Conditions

    Directory of Open Access Journals (Sweden)

    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.

  11. Physical Meaning of the Optimum Measurement Process in Quantum Detection Theory

    Science.gov (United States)

    Osaki, Masao; Kozuka, Haruhisa; Hirota, Osamu

    1996-01-01

    The optimum measurement processes are represented as the optimum detection operators in the quantum detection theory. The error probability by the optimum detection operators goes beyond the standard quantum limit automatically. However the optimum detection operators are given by pure mathematical descriptions. In order to realize a communication system overcoming the standard quantum limit, we try to give the physical meaning of the optimum detection operators.

  12. Fluidized-bed reactors processes and operating conditions

    CERN Document Server

    Yates, John G

    2016-01-01

    The fluidized-bed reactor is the centerpiece of industrial fluidization processes. This book focuses on the design and operation of fluidized beds in many different industrial processes, emphasizing the rationale for choosing fluidized beds for each particular process. The book starts with a brief history of fluidization from its inception in the 1940’s. The authors present both the fluid dynamics of gas-solid fluidized beds and the extensive experimental studies of operating systems and they set them in the context of operating processes that use fluid-bed reactors. Chemical engineering students and postdocs as well as practicing engineers will find great interest in this book.

  13. Optimum conditions of enzymatic hydrolysis of rice residue protein by alkaline protease%米渣蛋白碱性蛋白酶酶解条件优化

    Institute of Scientific and Technical Information of China (English)

    许尨; 袁江兰; 靳艳; 邓川; 李文竹

    2012-01-01

    Rice dreg is the quality of protein resources. This by-product from rice residue as raw material starch sugar enterprise, degree of hydrolysis and foaming index for evaluation, of enzymatic hydrolysis of rice residue protein by alkaline protease, first examine the enzyme adds volume, pH, substrate concentration, and other factors influence on the degree of hydrolysis of rice residue protein, and then came to the best enzymatic hydrolysis by response surface test conditions. The results show that the optimal conditions enzyme solution is substrate concentration 6%, enzyme solution time 90 min, add enzyme quantity 2%, pH 8.5, enzyme solution temperature 55 %, the conditions under which get enzyme solution liquid foaming ability high.%米渣是优质的蛋白质资源。以淀粉糖企业副产品米渣为原料,以水解度和起泡性为评价指标,利用碱性蛋白酶对米渣蛋白进行酶解,首先研究酶添加量、pH、底物浓度等因素对米渣蛋白质水解度的影响,然后通过响应面试验得出最佳酶解条件。结果表明,酶解最适条件是底物浓度6%、酶解时间90min、加酶量2%、pH为8.5、酶解温度55℃,在此条件下得到的酶解液起泡性高。

  14. Optimum Pipe Size Selection for Turbulent Flow

    Directory of Open Access Journals (Sweden)

    Timothy A. AKINTOLA

    2009-07-01

    Full Text Available Pipelines are normally designed to deliver fluid at the required head and flow rate in a cost effective manner. Increase in conduit diameter leads to increase in annual capital costs, and decrease in operating costs. Selection of an optimum conduit diameter for a particular fluid flow will therefore be a vital economic decision. This paper presents a computer aided optimisation technique for determination of optimum pipe diameter for a number of idealized turbulent flow. Relationships were formulated connecting theories of turbulent fluid flow with pipeline costing. These were developed into a computer program, written in Microsoft Visual C++ language, for a high-level precision estimate of the optimum pipe diameter, through the least total cost approach. The validity of the program was ascertained through case studies, representative of fluids with different densities and compressibility. The optimum conduit diameter was found to increase linearly with increase in compressibility.

  15. Optimum conditions for growth in liquid medium of Oscillatoria formosa Bory used as the principal food in laboratory culture of intermediate hosts for schistosomosis and fasciolosis

    Directory of Open Access Journals (Sweden)

    Ferreira Filipa M.

    2000-09-01

    Full Text Available The rearing of snails, intermediate hosts of Schistosoma haematobium, S. intercalatum, S. bovis and Fasciola hepatica is the first step to maintain the life cycle of these parasites in laboratory in order to have biological material for the different studies, namely on the systematic biology and immunodiagnostic of schistosomosis and fasciolosis. According to the traditional method, the alga Oscillatoria formosa Bory (Cyanobacteria, principal food source for the snails, was cultivated in soil extract (Sampaio Xavier et al., 1968. However, it was sometimes very difficult to find the proper soil extract and the material was also contaminated by protozoa and fungi. In our work, using a new medium having as a base the Mineral Medium II (modified from Hughes et al., 1958 we found that O. formosa had a better growth response than in the soil extract medium. Snails fed on O. formosa reached three times the size of others at the same age, and they also reached sex maturity earlier, having more egg-masses per snail and, in addition, the rate of survival as well as the number of generations per year under laboratory conditions significantly increased. This culture was also easier to perform, and the axenic conditions easier to maintain.

  16. Study of safety relief valve operation under ATWS conditions. [PWR

    Energy Technology Data Exchange (ETDEWEB)

    Hutmacher, E.S.; Nesmith, B.J.; Brukiewa, J.B.

    1979-06-25

    A literature survey and analysis project has been performed to determine if recent (since mid-1975) data has been reported which could influence the current approach to predicting PWR relief valve capacity under ATWS conditions. This study was conducted by the Energy Technology Engineering Center for NRC. Results indicate that the current relief valve capacity model tends to predict less capacity than actually obtains; however, no experimental verification at PWR ATWS conditions was found. Other project objectives were to establish the availability of methods for evaluating reaction forces and back pressure effects on relief valve capacity, and to determine if facilities exist which are capable of testing PWR relief valves at ATWS conditions.

  17. A method for the design of 3D scaffolds for high-density cell attachment and determination of optimum perfusion culture conditions.

    Science.gov (United States)

    Provin, Christophe; Takano, Kiyoshi; Sakai, Yasuyuki; Fujii, Teruo; Shirakashi, Ryo

    2008-01-01

    The application of in vitro cultured cells in tissue engineering or drug screening, aimed at complex soft tissues such as liver, requires in vivo physiological function of the cultured cells. For this purpose, the scaffold in which cells are cultured should provide a microenvironment similar to an in vivo one with a three-dimensional extracellular matrix, a high supply capacity of O(2) and nutrients, and high cell density. In this paper, we propose a method to design (1) the geometry of the scaffold, with a surface/volume ratio optimized to allow high-density (5 x 10(7)cells/mL) cell culture and (2) culture conditions that will supply optimal quantities of oxygen and nutrients. CFD modeling of mass transport was used to determine the shear stress as well as O(2) and glucose metabolism in the scaffold (20 mm width-35 mm length) for various flow rates. Validation of the model was done through comparison with flow resistance and micro-PIV experiments. CFD analysis showed the maximum metabolic rate densities for this scaffold are 6.04 x 10(-3)mol/s/m(3) for O(2) at 0.71 mL/min and 1.91 x 10(-2)mol/s/m(3) for glucose at 0.35 mL/min.

  18. Welded repair joints of boiler steels following operation in creep conditions exceeding the design time of operation

    Energy Technology Data Exchange (ETDEWEB)

    Dobrzanski, J.; Paszkowska, H.; Zielinski, A. [Institute for Ferrous Metallurgy, Gliwice (Poland)

    2010-07-01

    The assessment of suitability for further operation for materials and welded repair joints of thick-walled main steam pipeline components, made of steel 14MoV63, as well as steam superheater outlet headers made of steel X20CrMoV121 following operation in creep conditions in time periods considerably longer than the specified calculated time of operation. Strength properties, impact strength and transition temperature into brittle condition, as well as structure condition have been evaluated. On the basis of shortened creep tests, the residual life and disposable residual life of materials and welded joints have been determined. Material properties following operation and those of fabricated circumferential welded repair joints have been compared. The condition of examined components and suitability of the fabricated welded repair joints for further operation have been assessed. (orig.)

  19. 14 CFR 91.527 - Operating in icing conditions.

    Science.gov (United States)

    2010-01-01

    ...-Powered Multiengine Airplanes and Fractional Ownership Program Aircraft § 91.527 Operating in icing... adhering to the wings or stabilizing or control surfaces; or (3) Any frost adhering to the wings or... Aviation Regulation No. 23, or those for transport category airplane type certification, no pilot may...

  20. Operation Design of Wind Turbines in Strong Wind Conditions

    DEFF Research Database (Denmark)

    Shen, Wen Zhong; Montes, Melissa Barroso; Odgaard, Peter Fogh

    2012-01-01

    In order to reduce the impact on the electrical grid from the shutdown of MW wind turbines at wind speeds higher than the cut-out wind speed of 25 m/s, we propose in this paper to run the turbines at high wind speeds up to 40 m/s. Two different operation designs are made for both constant speed...

  1. The Optimum Replacement of Weapon

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiao; ZHANG Jin-chun

    2002-01-01

    The theory of LCC (Life Cycle Cost) is applied in this paper. The relation between the economic life of weapon and the optimum replacement is analyzed. The method to define the optimum replacement time of weapon is discussed.

  2. Investigation of optimum ohmic heating conditions for inactivation of Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium, and Listeria monocytogenes in apple juice.

    Science.gov (United States)

    Park, Il-Kyu; Ha, Jae-Won; Kang, Dong-Hyun

    2017-05-19

    Control of foodborne pathogens is an important issue for the fruit juice industry and ohmic heating treatment has been considered as one of the promising antimicrobial interventions. However, to date, evaluation of the relationship between inactivation of foodborne pathogens and system performance efficiency based on differing soluble solids content of apple juice during ohmic heating treatment has not been well studied. This study aims to investigate effective voltage gradients of an ohmic heating system and corresponding sugar concentrations (°Brix) of apple juice for inactivating major foodborne pathogens (E. coli O157:H7, S. Typhimurium, and L. monocytogenes) while maintaining higher system performance efficiency. Voltage gradients of 30, 40, 50, and 60 V/cm were applied to 72, 48, 36, 24, and 18 °Brix apple juices. At all voltage levels, the lowest heating rate was observed in 72 °Brix apple juice and a similar pattern of temperature increase was shown in18-48 °Brix juice samples. System performance coefficients (SPC) under two treatment conditions (30 V/cm in 36 °Brix or 60 V/cm in 48 °Brix juice) were relatively greater than for other combinations. Meanwhile, 5-log reductions of the three foodborne pathogens were achieved after treatment for 60 s in 36 °Brix at 30 V/cm, but this same reduction was observed in 48 °Brix juice at 60 V/cm within 20 s without affecting product quality. With respect to both bactericidal efficiency and SPC values, 60 V/cm in 48 °Brix was the most effective ohmic heating treatment combination for decontaminating apple juice concentrates.

  3. Remaining useful life estimation for deteriorating systems with time-varying operational conditions and condition-specific failure zones

    Institute of Scientific and Technical Information of China (English)

    Li Qi; Gao Zhanbao; Tang Diyin; Li Baoan

    2016-01-01

    Dynamic time-varying operational conditions pose great challenge to the estimation of system remaining useful life (RUL) for the deteriorating systems. This paper presents a method based on probabilistic and stochastic approaches to estimate system RUL for periodically moni-tored degradation processes with dynamic time-varying operational conditions and condition-specific failure zones. The method assumes that the degradation rate is influenced by specific oper-ational condition and moreover, the transition between different operational conditions plays the most important role in affecting the degradation process. These operational conditions are assumed to evolve as a discrete-time Markov chain (DTMC). The failure thresholds are also determined by specific operational conditions and described as different failure zones. The 2008 PHM Conference Challenge Data is utilized to illustrate our method, which contains mass sensory signals related to the degradation process of a commercial turbofan engine. The RUL estimation method using the sensor measurements of a single sensor was first developed, and then multiple vital sensors were selected through a particular optimization procedure in order to increase the prediction accuracy. The effectiveness and advantages of the proposed method are presented in a comparison with exist-ing methods for the same dataset.

  4. Model Skinner Operant Conditioning automata i bionički naučeno upravljanje robota

    OpenAIRE

    Cai, Jianxian; Hong, Li; Cheng, Lina; Yu, Ruihong

    2016-01-01

    Fuzzy Skinner Operant Conditioning Automaton (FSOCA) sastavljen je na temelju Operant Conditioning mehanizma primjenom teorije neizrazitih skupova. Osnovno obilježje automata FSOCA je sljedeće: neizraziti rezultati stanja pomoću Gausove funkcije koriste se kao skupovi neizrazitog stanja; neizrazita pravila preslikavanja (fuzzy mapping rules) kod fuzzy-conditioning-operacije zamjenjuju stohastičke "conditioning-operant" skupove preslikavanja. Stoga se automat FSOCA može koristiti za opisivanje...

  5. [Design, equipment, and management for air conditioning in operating room].

    Science.gov (United States)

    Fuji, Kumiko; Mizuno, Ju

    2011-11-01

    In order to maintain air cleanliness in the operating room (OR) permanently, air exchange rate in the OR should be more than 15 times x hr(-1), the laminar air flow should be kept, and the numbers of the persons in the OR and the numbers of opening and closing OR door should be limited. High efficiency particulate air (HEPA) filter is effective in collection and removal of airborne microbes, and is used in the biological clean room. We need to design, equip, and manage the OR environment according to Guideline for Design and Operation of Hospital HVAC Systems HEAS-02-2004 established by Healthcare Engineering Association of Japan and Guideline for Prevention of Surgical Site Infection (SSI) established by the Center for Disease Control and Prevention (CDC) in the USA.

  6. Skinner boxes for psychotics: Operant conditioning at Metropolitan state hospital

    OpenAIRE

    Rutherford, Alexandra

    2003-01-01

    Between 1953 and 1965, Ogden Lindsley and his associates conducted free-operant research with psychiatric inpatients and normal volunteers at Metropolitan State Hospital in Waltham, Massachusetts. Their project, originally named “Studies in Behavior Therapy,” was renamed “Harvard Medical School Behavior Research Laboratory” in 1955. This name change and its implications were significant. The role of the laboratory in the history of the relationship between the experimental analysis of behavio...

  7. Sleep Supports Inhibitory Operant Conditioning Memory in "Aplysia"

    Science.gov (United States)

    Vorster, Albrecht P. A.; Born, Jan

    2017-01-01

    Sleep supports memory consolidation as shown in mammals and invertebrates such as bees and "Drosophila." Here, we show that sleep's memory function is preserved in "Aplysia californica" with an even simpler nervous system. Animals performed on an inhibitory conditioning task ("learning that a food is inedible") three…

  8. Extraction of red cabbage anthocyanins: optimization of the operation conditions of the column process

    Directory of Open Access Journals (Sweden)

    Marcelo Fonseca Xavier

    2008-02-01

    Full Text Available The aim of this work was to extract anthocyanins from the red cabbage. Batch studies under several extraction conditions indicated that acetic acid in aqueous solution (10% V/V was the best solvent, used in the proportion of 0.25 g of red cabbage mL-1. At this condition, column assays were carried out to evaluate the influence of the ionic force, pH, solvent flow rate, recirculated volume of red cabbage juice and the mass of red cabbage. Results showed that the pH, recirculation and mass of red cabbage had statistically significant effects, where the optimum operation conditions found for the process were pH 2.3, recirculation volume of the solvent 0.83 L and mass of red cabbage 50 g.Desde os primórdios dos tempos as antocianinas são extraídas de vegetais, mas avanços que garantam um processo viável e rentável exigem conhecimento, quantificação e controle das condições de operação. Estudos em batelada sob várias condições de extração indicaram que ácido acético em solução aquosa (10% V/V foi o melhor solvente, quando usado na proporção de 0,25 g de repolho roxo mL-1. Nesta condição de operação foram feitos ensaios em coluna para avaliar a influência da força iônica, pH, taxa de escoamento do solvente, volume recirculado da solução de extração e massa de repolho roxo. Os resultados mostraram que o pH, recirculação e massa de repolho foram estatisticamente significativos, e as condições ótimas de operação encontradas para o processo foram pH 2,3, volume de solvente recirculado de 0,83 L e massa de repolho roxo igual a 50g.

  9. Remaining useful life estimation for deteriorating systems with time-varying operational conditions and condition-specific failure zones

    Directory of Open Access Journals (Sweden)

    Li Qi

    2016-06-01

    Full Text Available Dynamic time-varying operational conditions pose great challenge to the estimation of system remaining useful life (RUL for the deteriorating systems. This paper presents a method based on probabilistic and stochastic approaches to estimate system RUL for periodically monitored degradation processes with dynamic time-varying operational conditions and condition-specific failure zones. The method assumes that the degradation rate is influenced by specific operational condition and moreover, the transition between different operational conditions plays the most important role in affecting the degradation process. These operational conditions are assumed to evolve as a discrete-time Markov chain (DTMC. The failure thresholds are also determined by specific operational conditions and described as different failure zones. The 2008 PHM Conference Challenge Data is utilized to illustrate our method, which contains mass sensory signals related to the degradation process of a commercial turbofan engine. The RUL estimation method using the sensor measurements of a single sensor was first developed, and then multiple vital sensors were selected through a particular optimization procedure in order to increase the prediction accuracy. The effectiveness and advantages of the proposed method are presented in a comparison with existing methods for the same dataset.

  10. Modal test results of a ship under operational conditions

    DEFF Research Database (Denmark)

    Orlowitz, Esben; Brandt, Anders

    2014-01-01

    Skibe er udsat for et komplekst vibration miljø, påvirket af havet, samt driftsforholdene. Især er det vanskeligt at anslå analytisk værdier for de hydrodynamiske påvirkninger. Eksperimentelle resultater er derfor vigtigt for at kontrollere de analytiske modeller. I den foreliggende artikel præse...... fokuserer på driftsforhold påvirkning af de modal parametre og viser en betydelig variation af modal dæmpning af skibet i drift, med cirka 400%, 200% og 400% forskel i de første tre globale lodrette bøjning modes, ved forskellige operations hastigheder....

  11. 响应面法优化大豆种皮果胶的酸提取工艺%The optimum acid-extraction conditions of soybean hull pectin by response surface methodology

    Institute of Scientific and Technical Information of China (English)

    许旭; 杨桃; 陈新

    2013-01-01

      通过响应面分析法对大豆种皮中果胶的提取工艺进行优化.利用响应面实验设计考察pH值、提取温度、提取时间、和液料比四个因素对果胶得率的影响,探讨果胶提取的最佳工艺条件.通过响应面实验得出,pH值、液料比对果胶得率有显著影响,大豆种皮果胶提取的最佳工艺条为:pH1.54、提取温度89.9℃、提取时间90 min,果胶最大得率为8.37%.%To optimize the extraction process of the soybean hull pectin by response surface methodology .The influ-ence factors of extraction temperature,pH of HCl solution,extraction time and liquid-solid ratio were evaluated using a fractional design,to explore the optimum conditions of pectin extract .Obtained by experiment,both the pH of HCl solution and liquid -solid ratio had significant effects on the extraction rate ,the optimum conditions of pectin ex-traction were pH of HCl solution 1.54,extraction temperature 89.9℃,extraction time 90 min,liquid-solid ratio14, and the optimal pectin yield is 8.37%.

  12. Extending In Vitro Conditioning in "Aplysia" to Analyze Operant and Classical Processes in the Same Preparation

    Science.gov (United States)

    Brembs, Bjorn; Baxter, Douglas A.; Byrne, John H.

    2004-01-01

    Operant and classical conditioning are major processes shaping behavioral responses in all animals. Although the understanding of the mechanisms of classical conditioning has expanded significantly, the understanding of the mechanisms of operant conditioning is more limited. Recent developments in "Aplysia" are helping to narrow the gap in the…

  13. Influence of impurity gases and operating conditions on PAFC performance

    Energy Technology Data Exchange (ETDEWEB)

    Hirai, K.; Iwasa, N.; Suzuki, M.; Okada, O. [Osaka Gas Co., Ltd. (Japan)] [and others

    1996-12-31

    On-site Phosphoric Acid Fuel Cell (PAFC) Cogeneration system is installed at various test sites, such as at underground parking lot, within chemical plant premises and near urban streets. Since in the current PAFC system, cathode air is supplied to the cell with no particular pretreatment, impurity gases in the air might influence on cell performance. We have investigated the influence of various impurity gases in the cathode gas, on sub-scale single cells, and have found that NO{sub 2}, SO{sub 2} and toluene affect negatively on cell performance. The results of these experiments and the conceivable mechanism of these effects on cell degradation are reported. We have also investigated the influence of other operating parameters, such as temperature, current density, fuel utilization on cell performance. From these experiments, we have found that operating temperature is a significant factor, which mainly determines cell voltage decline rate. The results of sub-scale single cell tests and a short-stack verification test are also reported.

  14. The operant and the classical in conditioned orientation of Drosophila melanogaster at the flight simulator.

    Science.gov (United States)

    Brembs, B; Heisenberg, M

    2000-01-01

    Ever since learning and memory have been studied experimentally, the relationship between operant and classical conditioning has been controversial. Operant conditioning is any form of conditioning that essentially depends on the animal's behavior. It relies on operant behavior. A motor output is called operant if it controls a sensory variable. The Drosophila flight simulator, in which the relevant behavior is a single motor variable (yaw torque), fully separates the operant and classical components of a complex conditioning task. In this paradigm a tethered fly learns, operantly or classically, to prefer and avoid certain flight orientations in relation to the surrounding panorama. Yaw torque is recorded and, in the operant mode, controls the panorama. Using a yoked control, we show that classical pattern learning necessitates more extensive training than operant pattern learning. We compare in detail the microstructure of yaw torque after classical and operant training but find no evidence for acquired behavioral traits after operant conditioning that might explain this difference. We therefore conclude that the operant behavior has a facilitating effect on the classical training. In addition, we show that an operantly learned stimulus is successfully transferred from the behavior of the training to a different behavior. This result unequivocally demonstrates that during operant conditioning classical associations can be formed.

  15. The Operant and the Classical in Conditioned Orientation of Drosophila melanogaster at the Flight Simulator

    Science.gov (United States)

    Brembs, Björn; Heisenberg, Martin

    2000-01-01

    Ever since learning and memory have been studied experimentally, the relationship between operant and classical conditioning has been controversial. Operant conditioning is any form of conditioning that essentially depends on the animal's behavior. It relies on operant behavior. A motor output is called operant if it controls a sensory variable. The Drosophila flight simulator, in which the relevant behavior is a single motor variable (yaw torque), fully separates the operant and classical components of a complex conditioning task. In this paradigm a tethered fly learns, operantly or classically, to prefer and avoid certain flight orientations in relation to the surrounding panorama. Yaw torque is recorded and, in the operant mode, controls the panorama. Using a yoked control, we show that classical pattern learning necessitates more extensive training than operant pattern learning. We compare in detail the microstructure of yaw torque after classical and operant training but find no evidence for acquired behavioral traits after operant conditioning that might explain this difference. We therefore conclude that the operant behavior has a facilitating effect on the classical training. In addition, we show that an operantly learned stimulus is successfully transferred from the behavior of the training to a different behavior. This result unequivocally demonstrates that during operant conditioning classical associations can be formed. PMID:10753977

  16. Optimum conditions for concrete steam treatment

    Directory of Open Access Journals (Sweden)

    Mtschedlow-Petrossian, O. P.

    1974-09-01

    Full Text Available Not availableEl fraguado acelerado se obtiene la mayor parte de las veces en hormigones de cemento mediante elevadas temperaturas y con una humedad relativa del aire del 100%. Si se aplica el tratamiento hidrotérmico, sin tener en cuenta los procesos físicos y físicoquímicos que se desarrollan durante el fraguado, hay que contar con un consumo elevado de cemento y un largo tratamiento térmico. Además, las consecuencias son: reducidas resistencias mecánicas y una insuficiente resistencia a la helada.

  17. The dynamic behavior of sliding tribosystems in unstable operating conditions

    Science.gov (United States)

    Postaru, A.; Postaru, Ghe; Ceban, V.; Spânu, C.; Stoicev, P.

    2017-02-01

    The paper addresses the issue of the influence that the law of friction has on the dynamic behavior of the mechanical system that interacts with a tribosystem. The emergence of certain nonlinearities of higher order into the law of friction leads to an intensification of the dissipative process and to tribosystem destabilization. Consequently, friction excited self-oscillations are generated into the elements of the mechanical system with a wide spectrum of frequencies, sustained from the external source of energy. The theoretical and experimental modelling of the dissipative process and of the generation of is based on the frictional harmonic oscillator that interacts with the tribosystem. The oscillator is used as a sensitive element to the fluctuations of the frictional force and as a measure of the dissipated energy. Starting from the model, the elaboration of a method and of devices for experimental research provided the opportunity to study the behavior of the tribosystem in unstable operating

  18. Skinner boxes for psychotics: operant conditioning at Metropolitan State Hospital.

    Science.gov (United States)

    Rutherford, Alexandra

    2003-01-01

    Between 1953 and 1965, Ogden Lindsley and his associates conducted free-operant research with psychiatric inpatients and normal volunteers at Metropolitan State Hospital in Waltham, Massachusetts. Their project, originally named "Studies in Behavior Therapy," was renamed "Harvard Medical School Behavior Research Laboratory" in 1955. This name change and its implications were significant. The role of the laboratory in the history of the relationship between the experimental analysis of behavior and applied behavior analysis is discussed. A case is made for viewing Lindsley's early work as foundational for the subfield of the experimental analysis of human behavior that formally coalesced in the early 1980s. The laboratory's work is also contextualized with reference to the psychopharmacological revolution of the 1950s. Finally, a four-stage framework for studying the historical and conceptual development of behavior analysis is proposed.

  19. Operating conditions of batteries in off-grid renewable energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Svoboda, Vojtech [University of Hawaii, 1680 East-West Rd., Post 109, Honolulu, HI 96822, (United States); Wenzl, Heinz [Beratung fuer Batterien und Energietechnik, Am Bergwaeldchen 27, 37520 Osterode (Germany); Kaiser, Rudi [Fraunhofer Institute for Solar Energy Systems, Heidenhofstrasse 2, 79110 Freiburg (Germany); Jossen, Andreas [Center for Solar Energy and Hydrogen Research Baden - Wuerttemberg, Helmholtzstrasse 8, 89081 Ulm (Germany); Baring-Gould, Ian [National Renewable Energy Laboratory, MS 3811, 1617 Cole Blvd, 80401-3393 Golden/CO (United States); Manwell, James [University of Massachusetts, Amherst, Massachusetts, MA 01003 (United States); Lundsager, Per; Bindner, Henrik; Cronin, Tom; Noergaard, Per [Riseo National Laboratory, P.O. Box 49, Frederiksborgvej 399, 4000 Roskilde (Denmark); Ruddell, Alan [Council for the Central Laboratory of the Research Councils, Rutherford Appleton Laboratory, Energy Research Unit, Chilton, OX11 0QX Didcot (United Kingdom); Perujo, Adolfo; Douglas, Kevin [E.C. Joint Research Centre, Institute for Environment and Sustainability, 21020 Ispra VA (Italy); Rodrigues, Carlos; Joyce, Antonio [INETI, Department of Renewable Energy, Estrada do Paco de Lumiar 22, 1649-038 Lisbon (Portugal); Tselepis, Stathis [Center for Renewable Energy Sources, 19th km Marathonos Ave., 19009 Pikermi (Greece); Borg, Nico van der; Nieuwenhout, Frans [The Netherlands Energy Research Foundation, P.O. Box 1, 1755 ZG Petten (Netherlands); Wilmot, Nigel [Research Institute for Sustainable Energy, Murdoch University, South Street, 6150 Perth (Australia); Mattera, Florence [Commissariat a l' Energetie Atomicque, Groupement Energetique de Cadarache, 38054 Grenoble (France)

    2007-11-15

    Operating conditions in off-grid renewable energy systems (RES) vary significantly in different applications and locations. To describe RES and the operating conditions of their components it is useful to define categories of similar operating conditions. Categories can also be used for lifetime considerations of RES components, for making recommendations and for analysing the properties and performance of a RES and its components. Categories support system designers and an economic analysis. This paper describes the process and the results of creating RES categories of similar operating conditions for batteries. Categories are defined in such a way that batteries belonging to the same category are subjected to similar operating conditions and a similar combination of stress factors. The results provide a comprehensive overview of battery operating conditions in existing off-grid renewable energy systems. This work is part of the EU research project Benchmarking. (author)

  20. Operating conditions of batteries in off-grid renewable energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Svoboda, Vojtech; Wenzl, Heinz; Kaiser, Rudi; Jossen, Andreas; Baring-Gould, Ian; Manwell, James; Lundsager, Per; Bindner, Henrik; Cronin, Tom; Nørgård, Per; Ruddell, Alan; Perujo, Adolfo; Douglas, Kevin; Rodrigues, Carlos; Joyce, António; Tselepis, Stathis; van der Borg, Nico; Nieuwenhout, Frans; Wilmot, Nigel; Mattera, Florence; Sauer, Dirk Uwe

    2007-11-01

    Operating conditions in off-grid renewable energy systems (RES) vary significantly in different applications and locations. To describe RES and the operating conditions of their components it is useful to define categories of similar operating conditions. Categories can also be used for lifetime considerations of RES components, for making recommendations and for analysing the properties and performance of a RES and its components. Categories support system designers and an economic analysis. This paper describes the process and the results of creating RES categories of similar operating conditions for batteries. Categories are defined in such a way that batteries belonging to the same category are subjected to similar operating conditions and a similar combination of stress factors. The results provide a comprehensive overview of battery operating conditions in existing off-grid renewable energy systems. This work is part of the EU research project Benchmarking.

  1. Operating conditions of batteries in off-grid renewable energy systems

    DEFF Research Database (Denmark)

    Svoboda, V.; Wenzl, H.; Kaiser, R.

    2007-01-01

    Operating conditions in off-grid renewable energy systems (RES) vary significantly in different applications and locations. To describe RES and the operating conditions of their components it is useful to define categories of similar operating conditions. Categories can also be used for lifetime...... considerations of RES components, for making recommendations and for analysing the properties and performance of a RES and its components. Categories support system designers and an economic analysis. This paper describes the process and the results of creating RES categories of similar operating conditions...... for batteries. Categories are defined in such a way that batteries belonging to the same category are subjected to similar operating conditions and a similar combination of stress factors. The results provide a comprehensive overview of battery operating conditions in existing off-grid renewable energy systems...

  2. Effects of organic phase, fermentation media, and operating conditions on lactic Acid extraction.

    Science.gov (United States)

    Hossain, Md Monwar; Maisuria, J L

    2008-01-01

    Lactic acid has extensive uses in the food, pharmaceutical, cosmetic and chemical industry. Lately, its use in producing biodegradable polymeric materials (polylactate) makes the production of lactic acid from fermentation broths very important. The major part of the production cost accounts for the cost of separation from very dilute reaction media where productivity is low as a result of the inhibitory nature of lactic acid. The current method of extraction/separation is both expensive and unsustainable. Therefore, there is great scope for development of alternative technology that will offer efficiency, economic, and environmental benefits. One of the promising technologies for recovery of lactic acid from fermentation broth is reactive liquid-liquid extraction. In this paper the extraction and recovery of lactic acid based on reactive processes is examined and the performance of a hydrophobic microporous hollow-fiber membrane module (HFMM) is evaluated. First, equilibrium experiments were conducted using organic solutions consisting of Aliquat 336/trioctylamine (as a carrier) and tri-butyl phosphate (TBP)/sunflower oil (as a solvent) The values of the distribution coefficient were obtained as a function of feed pH, composition of the organic phase (ratio of carrier to solvent), and temperature (range 8-40 degrees C). The optimum extraction was obtained with the organic phase consisting of a mixture of 15 wt % tri-octylamine (TOA) and 15% Aliquat 336 and 70% solvent. The organic phase with TBP performed best but is less suitable because of its damaging properties (toxicity and environmental impact) and cost. Sunflower oil, which performed moderately, can be regarded as a better option as it has many desirable characteristics (nontoxic, environment- and operator-friendly) and it costs much less. The percentage extraction was approximately 33% at pH 6 and at room temperature (can be enhanced by operating at higher temperatures) at a feed flow rate of 15-20 L

  3. Spatial optimum collocation model of urban land and its algorithm

    Science.gov (United States)

    Kong, Xiangqiang; Li, Xinyun

    2007-06-01

    Optimizing the allocation of urban land is that layout and fix position the various types of land-use in space, maximize the overall benefits of urban space (including economic, social, environment) using a certain method and technique. There is two problems need to deal with in optimizing the allocation of urban land in the technique: one is the quantitative structure, the other is the space structure. In allusion to these problems, according to the principle of spatial coordination, a kind of new optimum collocation model about urban land was put forward in this text. In the model, we give a target function and a set of "soft" constraint conditions, and the area proportions of various types of land-use are restricted to the corresponding allowed scope. Spatial genetic algorithm is used to manipulate and calculate the space of urban land, the optimum spatial collocation scheme can be gradually approached, in which the three basic operations of reproduction, crossover and mutation are all operated on the space. Taking the built-up areas of Jinan as an example, we did the spatial optimum collocation experiment of urban land, the spatial aggregation of various types is better, and an approving result was got.

  4. Automated system for efficient microwave power coupling in an S-band ECR ion source driven under different operating conditions

    Energy Technology Data Exchange (ETDEWEB)

    Muguira, L., E-mail: lmuguira@essbilbao.org [ESS-Bilbao, Edificio Rectorado, Vivero de Empresas, 48940 Leioa (Bizkaia) (Spain); Portilla, J. [University of Basque Country (UPV/EHU), Department of Electricity and Electronics, Science and Technology Faculty, 48940 Leioa (Bizkaia) (Spain); Gonzalez, P.J.; Garmendia, N.; Feuchtwanger, J. [ESS-Bilbao, Edificio Rectorado, Vivero de Empresas, 48940 Leioa (Bizkaia) (Spain); Etxebarria, V. [University of Basque Country (UPV/EHU), Department of Electricity and Electronics, Science and Technology Faculty, 48940 Leioa (Bizkaia) (Spain); Eguiraun, M.; Arredondo, I.; Miracoli, R.; Belver, D. [ESS-Bilbao, Edificio Rectorado, Vivero de Empresas, 48940 Leioa (Bizkaia) (Spain)

    2014-03-21

    This article presents an automated system for optimizing the microwave power coupling to the plasma generated in a proton/deuteron Electron Cyclotron Resonance (ECR) source, based on a specific model of a rectangular waveguide triple-stub tuner and the integrated measurement and control electronics, helping to get stable plasma states. The control and improvement of the RF power absorption into the plasma is a complex process, essential for the ion source development and optimization under different operating conditions. A model and a matching algorithm for the triple-stub tuner have been developed and, besides, different methods to accurately measure the power transfer in a waveguide RF system have been studied and deployed in the ESS-Bilbao ion source system. The different parts have been integrated through a controller, which allows to run an automatic plasma matching system in closed loop. The behavior of the system implemented for low and high power regimes has been tested under different conditions: with several load impedances, with plasma inside the chamber, in continuous wave and pulsed wave operation modes, demonstrating power absorption typically over 90% in all the ion source configurations. The developed system allows to achieve significant improvement in the ECR ion source power absorption efficiency, both in continuous and pulsed mode. The automatic tuning unit enhances the system operation finding an optimum solution much faster than manually, also behaving as an adaptive system able to respond in few pulses to ion source configuration changes to maintain the power coupling as high as possible. - Highlights: • An automated system optimizing plasma and microwave power interaction is presented. • A model and a matching algorithm for the triple-stub tuner have been developed. • Different methods to measure the power transfer have been studied and deployed. • The system works for low or high power regimes under different ion source conditions.

  5. 液相色谱-质谱联用仪的最佳校准条件的选择%Selection of Optimum Calibration Conditions in Calibrating Liquid Chromatograph-mass Spectrometer

    Institute of Scientific and Technical Information of China (English)

    施江焕

    2013-01-01

    Liquid chromatograph and mass spectrometer was coupled together to the analytical instrument by a certain interface.Based on the working principle and structure of Liquid chromatograph-mass spectrometer,for setting the calibration parameter of the instrument,the technique of selecting optimum calibration conditions in calibrating Liquid chromatograph-mass spectrometer was studied by the analysis of the chromatographic conditions,instrument tuning and mass spectrometry conditions.So it could ensure to calibrate Liquid chromatograph-mass spectrometer accurately and provide some guidance on the calibration for Metrological institutions.%液相色谱-质谱联用仪是将液相色谱仪与质谱仪通过一定的接口耦合到一起的分析仪器.本文从色质谱联用仪的工作原理及结构入手,针对仪器校准时的参数设置,通过分析色谱条件、仪器调谐、质谱条件等因素,介绍了色质联用仪最佳校准条件的选择技巧,有力保证了对液质联用仪进行准确的计量校准,为计量检定机构开展校准工作提供了参考.

  6. Field quality of the LHC dipole magnets in operating conditions

    CERN Document Server

    Bottura, L; Fartoukh, Stéphane David; Russenschuck, Stephan; Sanfilippo, S; Scandale, Walter; Schmidt, F; Todesco, Ezio; Walckiers, L; Wolf, R

    2002-01-01

    We report here the main results of the field measurements performed so far on the pre-series LHC superconducting dipoles at superfluid helium temperature. After discussing the results at injection and collision conditions, we focus on the non-linear contributions at high field, on the contribution of superconductor magnetization at injection, and on ramp rate effects. The statistics accumulated on the first magnets of the production verify the hypotheses that have been used to design the correctors scheme for the LHC. In particular high field saturation is in line with the expectations, although a small systematic deformation due to Lorentz forces affects both sextupole and decapole terms. The decay at injection and snap-back at beginning of beam acceleration require careful characterization.

  7. Upgrading of coker distillate under variable hydrotreating operating conditions

    Directory of Open Access Journals (Sweden)

    H.A. Elsayed

    2011-06-01

    Full Text Available Studies on hydrotreating coker distillates, produced from a delayed coker unit were done using a commercially available CoMo/γ-Al2O3 catalyst, on which 0.2 wt% P2O5 was added in order to improve its characteristics. The experimental studies were conducted in a fixed-bed continuous-reactor (cata-test unit at temperatures (300–400 °C and total hydrogen pressure (40–65 bar. These conditions have affected the feedstock characteristics and great reduction of sulfur, aromatics and boiling ranges. Other improvements were obtained in diesel index (DI due to hydrogenation reaction of aromatics and desulfurization of its sulfur contents.

  8. Effect of Drying Operating Conditions on Canola Oil Tocopherol Content

    Directory of Open Access Journals (Sweden)

    Daniela Laoretani

    2014-03-01

    Full Text Available The aim of this work was to evaluate two operating parameters of seed drying (temperature and initial moisture content on the tocopherol content of canola oil. The raw material was characterized by moisture, oil, protein, crude fiber and ash content. Seeds at 13.6% and 22.7% moisture content (dry basis, db were dried at temperatures in the range of 35–100 °C to a safe storage moisture of 7% db. Oil was extracted from each treated sample. The oil extracted from the samples dried at the extreme temperatures was analyzed by means of the acidity value, peroxide index and fatty acid composition, finding no significant differences among treatments or among untreated and treated samples. Tocopherol contents in the oils obtained for all the assayed temperatures were determined. Differences were found for the samples with 22.7% (db initial moisture content. Except at 35 °C, temperature affected negatively the oil tocopherol content. However, when 13.6% (db moisture seeds were processed, no significant differences were observed in the amount of this minor oil component among assays.

  9. Optimum Preparation Conditions of LiNi0.8Co0.2O2 and LiNi0.95Ce0.05O2 as Lithium-Ion Battery Cathode Materials

    Institute of Scientific and Technical Information of China (English)

    豆志河; 张廷安; 侯闯

    2004-01-01

    The preparation of LiNi0.8Co0.2O2 was discussed by the multiply sintering method for solid reaction,in which the sintered material was smashed,ground and pelletted between two successive sintering steps.The optimum technological condition was obtained through orthogonal experiments by L9(34) and DTA analysis.The result indicates that the factors of effecting the electrochemical properties of synthesized LiNi0.8Co0.2O2 are molar ratio of Li/Ni/Co,oxygen pressure,homothermal time,the final sintering temperature in turn according to its importance.The oxygen pressure is reviewed independently and the technological condition is further optimized.With the same method,rare earth element Ce was studied as substitute element of Co and the cathode material of LiNi0.95Ce0.05O2 with excellent electrochemical properties was prepared.The electrochemical testing results of LiNi0.8Co0.2O2 and LiNi0.95Ce0.05O2 experimental batteries show that discharge capacities of them reach 165 and 148 mAh·g-1 respectively and the persistence is more than 9 h at 3.7 V.

  10. Optimization of automotive Rankine cycle waste heat recovery under various engine operating condition

    Science.gov (United States)

    Punov, Plamen; Milkov, Nikolay; Danel, Quentin; Perilhon, Christelle; Podevin, Pierre; Evtimov, Teodossi

    2017-02-01

    An optimization study of the Rankine cycle as a function of diesel engine operating mode is presented. The Rankine cycle here, is studied as a waste heat recovery system which uses the engine exhaust gases as heat source. The engine exhaust gases parameters (temperature, mass flow and composition) were defined by means of numerical simulation in advanced simulation software AVL Boost. Previously, the engine simulation model was validated and the Vibe function parameters were defined as a function of engine load. The Rankine cycle output power and efficiency was numerically estimated by means of a simulation code in Python(x,y). This code includes discretized heat exchanger model and simplified model of the pump and the expander based on their isentropic efficiency. The Rankine cycle simulation revealed the optimum value of working fluid mass flow and evaporation pressure according to the heat source. Thus, the optimal Rankine cycle performance was obtained over the engine operating map.

  11. Field study evaluation of diffuse ceiling ventilation in classroom during real operating conditions

    DEFF Research Database (Denmark)

    Kristensen, Martin Heine; Jensen, Jakob Søland; Heiselberg, Per Kvols

    2017-01-01

    Highlights •Field experimental measurements during real operating conditions. •Evaluation of pressure chamber effect. •Evaluation of displacement effect. •Evaluation of thermal comfort.......Highlights •Field experimental measurements during real operating conditions. •Evaluation of pressure chamber effect. •Evaluation of displacement effect. •Evaluation of thermal comfort....

  12. Effect of operational conditions on the degradation of organic matter and development of microalgae-bacteria consortia when treating swine slurry.

    Science.gov (United States)

    González-Fernández, Cristina; Riaño-Irazábal, Berta; Molinuevo-Salces, Beatriz; Blanco, Saúl; García-González, Maria Cruz

    2011-05-01

    There is great controversy regarding the best substrate (fresh or anaerobically digested swine slurry) for the development of microalgae-bacteria consortia. This study aims to elucidate the best substrate by assessing biomass productivity, microorganism predominance, and their ability for organic matter removal. In addition to the different substrates, different operational conditions and influent strengths were evaluated. Increasing organic matter content when favourable temperature and illumination conditions were present improved biomass production. However, these conditions were not favourable for microalgal growth, but they were favourable for bacteria. Regardless of the operational conditions, reactors fed with fresh slurry not only resulted in the highest biomass productivity, but also the greatest removal of total and soluble chemical oxygen demand (COD). On the other hand, reactors fed with digested slurry showed biomass productivity and COD removal values lower than those obtained for reactors fed with fresh slurry, most probably due to the recalcitrant nature of the former. Nevertheless, digested slurry was the substrate more appropriate for microalgae growth under harsh operational conditions (16 °C and 9-h illumination) at low influent strength and optimum operational conditions (30 °C and 24-h illumination) at higher influent strength.

  13. Neural Operant Conditioning as a Core Mechanism of Brain-Machine Interface Control

    Directory of Open Access Journals (Sweden)

    Yoshio Sakurai

    2016-08-01

    Full Text Available The process of changing the neuronal activity of the brain to acquire rewards in a broad sense is essential for utilizing brain-machine interfaces (BMIs, which is essentially operant conditioning of neuronal activity. Currently, this is also known as neural biofeedback, and it is often referred to as neurofeedback when human brain activity is targeted. In this review, we first illustrate biofeedback and operant conditioning, which are methodological background elements in neural operant conditioning. Then, we introduce research models of neural operant conditioning in animal experiments and demonstrate that it is possible to change the firing frequency and synchronous firing of local neuronal populations in a short time period. We also debate the possibility of the application of neural operant conditioning and its contribution to BMIs.

  14. Impact of air conditioning system operation on increasing gases emissions from automobile

    Science.gov (United States)

    Burciu, S. M.; Coman, G.

    2016-08-01

    The paper presents a study concerning the influence of air conditioning system operation on the increase of gases emissions from cars. The study focuses on urban operating regimes of the automobile, regimes when the engines have low loads or are operating at idling. Are presented graphically the variations of pollution emissions (CO, CO2, HC) depending of engine speed and the load on air conditioning system. Additionally are presented, injection duration, throttle position, the mechanical power required by the compressor of air conditioning system and the refrigerant pressure variation on the discharge path, according to the stage of charging of the air conditioning system.

  15. Optimum strain configurations for carrier injection in near infrared Ge lasers

    Science.gov (United States)

    Aldaghri, O.; Ikonić, Z.; Kelsall, R. W.

    2012-03-01

    The behavior of direct and indirect valleys in Ge, and the bandgap shrinking, under different tensile-strain conditions in bulk Ge and Ge quantum well structures are explored using the deformation potential and k .p methods. The doping density required for filling the indirect valleys up to the Γ-valley is calculated for various strain and growth conditions, as well as the efficiency of electron injection into the Γ-valley, and the optimum cases for Ge laser operation are identified.

  16. Vertical flow-constructed wetlands for domestic wastewater treatment under tropical conditions: effect of different design and operational parameters.

    Science.gov (United States)

    Bohórquez, Eliana; Paredes, Diego; Arias, Carlos Alberto

    2017-01-01

    This study assessed the treatment of domestic wastewater to find the optimum vertical flow-constructed wetland (VFCW) configuration under tropical conditions. Eight pilot-scale configurations units were studied to compare between fine sand and medium gravel used as substrate, two feeding frequencies (20 pulses d(-1) and 10 pulses d(-1)), and the presence or absence of tropical plants (Heliconia psittacorum). The results showed that the sand beds were significantly more efficient in the removal of organic matter, ammonia nitrogen, and total suspended solids than gravel beds, presenting average removal rates of 48 and 24 g m(-2) d(-1) of COD; 35 and 16 g m(-2) d(-1) of BOD5; 7 and 4 g m(-2) d(-1) of [Formula: see text]; 9 and 0 g m(-2) d(-1) for sand and gravel, respectively. The oxygen consumption rates were calculated and a value of 65 g m(-2) d(-1) was obtained for sand beds while for the gravel beds the consumption rate was 30 g m(-2 )d(-1). The assessment of different kinds of nitrogen showed interesting dynamics in the nitrification processes. The presence of H. psittacorum showed positive effects in the total nitrogen (TN) removal. The different loading frequencies applied did not show significant statistical differences in the removal of the tested contaminants. Preliminary results were found in the pathogen removal, where the sand is favorable as the substrate. This work represents the first step in the research of optimum VFWC design and operation parameters for Colombia as well as the use of plants of the genus Heliconia.

  17. Condition Monitoring of Machinery in Non-Stationary Operations : Proceedings of the Second International Conference "Condition Monitoring of Machinery in Non-Stationnary Operations"

    CERN Document Server

    Bartelmus, Walter; Chaari, Fakher; Zimroz, Radoslaw; Haddar, Mohamed

    2012-01-01

    Condition monitoring of machines in non-stationary operations (CMMNO) can be seen as the major challenge for research in the field of machinery diagnostics. Condition monitoring of machines in non-stationary operations is the title of the presented book and the title of the Conference held in Hammamet - Tunisia March 26 – 28, 2012. It is the second conference under this title, first took place in Wroclaw - Poland , March 2011. The subject CMMNO comes directly from industry needs and observation of real objects. Most monitored and diagnosed objects used in industry works in non-stationary operations condition. The non-stationary operations come from fulfillment of machinery tasks, for which they are designed for. All machinery used in different kind of mines, transport systems, vehicles like: cars, buses etc, helicopters, ships and battleships and so on work in non-stationary operations. The papers included in the book are shaped by the organizing board of the conference and authors of the papers. The papers...

  18. 晶体球中非相位匹配二次谐波产生及最佳聚焦条件%Non-Phase-Matched Second-Harmonic Generation and Optimum Focusing Condition in Crystal Sphere

    Institute of Scientific and Technical Information of China (English)

    阎江; 杨学林; 李浩文; 谢绳武; 丁良恩

    2000-01-01

    The sphere method is a newly-developed technique for mesurement of nonlinear optical coefficients in crystals. Based on the theory of aperture function of the focused Gaussian beam SHG, the non-phase-matched (NPM) SHG process in a crystal sphere is analyzed, and the optimum focus condition of type Ⅰ NPM SHG is discussed. The experiment of NPM SHG in a LiNbOa crystal sphere pumped with a pico-second laser pulse is reported. The experimental results agree well with the theoretical prediction.%晶体球法是近年来在国际上发展起来的一种测量非线性系数的新方法。根据聚焦高斯光束二次谐波产生的孔径方程理论,分析了晶体球中的第1类非相位匹配二次谐波产生过程,讨论了晶体球中第1类非相位匹配二次谐波最佳聚焦参数的选择。报道了LiNbo3晶体球中皮秒激光脉冲抽运的非相位匹配二次谐波实验。所得结果与理论预计相符。

  19. 扩展青霉利用苹果渣发酵产果胶酶条件的优化%Study on the optimum fermentation condition of producing pectinase by Penicillium expansum using apple pomase

    Institute of Scientific and Technical Information of China (English)

    吕丽娟; 樊明涛; 刘晓娇; 何鸿举; 魏新元

    2011-01-01

    通过单因素及二次旋转正交实验,对扩展青霉YL-9固体发酵产果胶酶的培养条件进行了探索.结果表明:最佳培养基组成为:麸皮8.15%、苹果渣16.5%、(NH4)2SO20.86%、MnSO40.3%、KCl 0.15%、0.04%的吐温80、加水量74.0%.采用最佳培养基配方,在250mL三角瓶中于28℃下恒温培养96h,果胶酶酶活可达到752.29U/g干曲.%Single factors and orthogonal rotation experiments were carried out to optimize pectinase producing conditions by Penicillium expansum under solid state fermentation. The results showed that the optimum medium compositions were as follows: bran 8.15%, apple pomace 16.5%, (NH4)2SO4 0.86%, MnSO4 0.3% , KCl 0.15%, Tween 80 0.04% and water content 74.0%.Using the optimized medium in 250mL flask,incubating at 28℃ for 96h, activity of pectinase reached 752.29U/g medium.

  20. Store operation with conditional push of a tag value to a queue

    Energy Technology Data Exchange (ETDEWEB)

    Heidelberger, Philip; Steinmacher-Burow, Burkhard

    2015-07-28

    According to one embodiment, a method for a store operation with a conditional push of a tag value to a queue is provided. The method includes configuring a queue that is accessible by an application, setting a value at an address in a memory device including a memory and a controller, receiving a request for an operation using the value at the address and performing the operation. The method also includes the controller writing a result of the operation to the address, thus changing the value at the address, the controller determining if the result of the operation meets a condition and the controller pushing a tag value to the queue based on the condition being met, where the tag value in the queue indicates to the application that the condition is met.

  1. Analysis of Fukushima unit 2 accident considering the operating conditions of RCIC system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Il, E-mail: sikim@kaeri.re.kr; Park, Jong Hwa; Ha, Kwang Soon; Cho, Song-Won; Song, JinHo

    2016-03-15

    Highlights: • Fukushima unit 2 accident was analyzed using MELCOR 1.8.6. • RCIC operating conditions were assumed and best case was selected. • Effect of RCIC operating condition on accident scenario was found. - Abstract: A severe accident in Fukushima occurred on March 11, 2011 and units 1, 2 and 3 were damaged severely. A tsunami following an earthquake made the supply of electricity power stop, and the safety systems, which use AC or DC power in plants could not operate properly. It is supposed that the degree of core degradation of unit 2 is less serious than in the other plants, and it was estimated that the operation of reactor core isolation cooling (RCIC) system at the initial stage of the accident minimized the core damage through decay heat removal. Although the operating conditions of the RCIC system are not known clearly, it can be important to analyze the accident scenario of unit 2. In this study, best case of the Fukushima unit 2 accident was presented considering the operating conditions of the RCIC system. The effects of operating condition on core degradation and fission product release rate to environment were also examined. In addition, importance of torus room flooding level in the accident analysis was discussed. MELCOR 1.8.6 was used in this research, and the geometries of plant and operating conditions of safety system were obtained from TEPCO through OECD/NEA BSAF Project.

  2. Effect of RCIC Operating Conditions on the Accident Scenario in Fukushima Unit 2

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sung Il; Park, Jong Hwa; Ha, Kwang Soon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    This study was conducted by using MELCOR 1.8.6. Fukushima unit 2 accident was analyzed using MELCOR in this study, and best estimate scenario with considering RCIC operating conditions was presented. Researches on the boiling water reactor (BWR) plant with reactor core isolation cooling (RCIC) system have been conducted. Research on the RCIC operation in Fukushima unit 2 was also conducted by Sandia National Laboratory. MELCOR analysis of the Fukushima unit 2 accident was conducted in the report and energy balance in wetwell was described by considering RCIC operation. However, the effect of RCIC operation condition on the accident scenario has not been studied. The operating conditions of RCIC system affect the pressures in wetwell and drywell, and the high pressure can make leakage path of fission product from PCV to reactor building. Thus it can be directly related with the amount of fission product which released to environment. In this study, severe accident on Fukushima unit 2 was analyzed considering the operating condition of RCIC system, and best estimated scenario was presented. In addition, the effect of RCIC turbine efficiency on the accident progression was examined. Energy balance in suppression chamber was also considered with discussion on the effect of torus room flooding level. It was found that the operating condition of RCIC turbine not only affects the variation of drywell pressure but also the amount of released fission products to environment. It was also confirmed that the RCIC turbine efficiency in the accident would be less than normal operating condition.

  3. Extraction of lycopene from tomato skin with supercritical carbon dioxide: effect of operating conditions and solubility analysis.

    Science.gov (United States)

    Topal, Ummihan; Sasaki, Mitsuru; Goto, Motonobu; Hayakawa, Kiro

    2006-07-26

    Supercritical carbon dioxide (SCCO2) extraction of lycopene from waste tomato skins was investigated. The experiments were carried out at pressures and temperatures ranging from 20 to 50 MPa and 313 to 373 K, respectively, without any modifiers. The flow rate of CO2 was maintained at 2.5 mL/min for 330 min extraction time. Solvent flow rate effect was examined for CO2 flow rates from 1.5 to 4.5 mL/min. The extracts were analyzed by high-performance liquid chromatography and UV-visible spectroscopy. The results showed that with optimized operating conditions, the maximum yield of lycopene (1.18 mg of lycopene/g of sample) was obtained at 40 MPa, 373 K, and 2.5 mL of CO2/min. Chromatographic analysis indicated that lycopene was extracted from tomato skin with negligible degradation at the optimum conditions and the amount extracted represented more than 94% of the total carotenoid content of the sample. The solubility of lycopene was modeled by use of the Chrastil equation.

  4. Operational-Condition-Independent Criteria Dedicated to Monitoring Wind Turbine Generators: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Yang, W.; Sheng, S.; Court, R.

    2012-08-01

    To date the existing wind turbine condition monitoring technologies and commercially available systems have not been fully accepted for improving wind turbine availability and reducing their operation and maintenance costs. One of the main reasons is that wind turbines are subject to constantly varying loads and operate at variable rotational speeds. As a consequence, the influences of turbine faults and the effects of varying load and speed are coupled together in wind turbine condition monitoring signals. So, there is an urgent need to either introduce some operational condition de-coupling procedures into the current wind turbine condition monitoring techniques or develop a new operational condition independent wind turbine condition monitoring technique to maintain high turbine availability and achieve the expected economic benefits from wind. The purpose of this paper is to develop such a technique. In the paper, three operational condition independent criteria are developed dedicated for monitoring the operation and health condition of wind turbine generators. All proposed criteria have been tested through both simulated and practical experiments. The experiments have shown that these criteria provide a solution for detecting both mechanical and electrical faults occurring in wind turbine generators.

  5. Treatment of oily wastewater by ultrafiltration: The effect of different operating and solution conditions

    Energy Technology Data Exchange (ETDEWEB)

    Hesampour, M

    2009-07-01

    In many industries, such as petroleum production, and the petrochemical, metal, food and cosmetics industries, wastewaters containing an emulsion of oil in water are often produced. The emulsions consist of water (up to 90%), oils (mineral, animal, vegetable and synthetic), surfactants and other contaminates. In view of its toxic nature and its deleterious effects on the surrounding environment (soil, water) such wastewater needs to be treated before release into natural water ways. Membrane-based processes have successfully been applied in industrial applications and are considered as possible candidates for the treatment of oily wastewaters. Easy operation, lower cost, and in some cases, the ability to reduce contaminants below existing pollution limits are the main advantages of these systems. The main drawback of membranes is flux decline due to fouling and concentration polarisation. The complexity of oil-containing systems demands complementary studies on issues related to the mitigation of fouling and concentration polarisation in membranebased ultrafiltration. In this thesis the effect of different operating conditions (factors) on ultrafiltration of oily water is studied. Important factors are normally correlated and, therefore, their effect should be studied simultaneously. This work uses a novel approach to study different operating conditions, like pressure, flow velocity, and temperature, and solution properties, like oil concentration (cutting oil, diesel, kerosene), pH, and salt concentration (CaCl{sub 2} and NaCl)) in the ultrafiltration of oily water, simultaneously and in a systematic way using an experimental design approach. A hypothesis is developed to describe the interaction between the oil drops, salt and the membrane surface. The optimum conditions for ultrafiltration and the contribution of each factor in the ultrafiltration of oily water are evaluated. It is found that the effect on permeate flux of the various factors studied strongly

  6. EXPERIMENTAL STUDY OF EFFECTS OF OPERATING CONDITIONS ON THE FLOW CHARACTERISTICS OF WATER HYDRAULIC THROTTLE

    Institute of Scientific and Technical Information of China (English)

    Liu Yinshui; Nie Songlin; Zhu Yuquan; He Xiaofeng; Li Zhuangyun

    2004-01-01

    Experimental investigations are made on the effects of operating conditions on the flow characteristics of throttle when tap water is used as the working media. The researched throttles include cone poppet valve, ball valve, disc valve and dumping orifice. Operating condition includes poppet lift, working media, back pressure, medium temperature, etc. Because the vapourous pressure of water is much higher than that of oil, cavitation is easier to occur in water hydraulic elements and systems, so the effects of operating conditions on the cavitation characteristics of throttle are also researched.

  7. Reliability Based Optimum Design of a Gear Box

    Directory of Open Access Journals (Sweden)

    D.Madhusekhar

    2014-10-01

    Full Text Available The gear box represents an important mechanical sub system. In machine tools, the propose of a gear box is to provide a series of useful output speeds so that the machining operation can be carried out at its most optimum operating conditions high spindle speeds with low feed rate for roughing operations. An important aspect in the design of machine tool transmission is to keep the cost and volume of the gear box to a minimum. The probabilistic approach to design has been considered to be more rational compared to the conventional design approach based on the factor of safety. The existence of uncertainties in either engineering simulations or manufacturing processes calls for a reliability-based design optimization (RBDO model for robust and cost-effective designs. In the present work a three shaft four speed gear box is designed using reliability principles. For the specified reliability of the system (Gear box, component reliability (Gear pair is calculated by considering the system as a series system. Design is considered to be safe and adequate if the probability of failure of gear box is less than or equal to a specified quantity in each of the two failure modes. A FORTRAN program has been developed to calculate the mean values of face widths of gears for the minimum mass of gear box. By changing the probability of failure of system variations in the face widths are studied. The reliability based optimum design results are compared with those obtained by deterministic optimum design. The minimum mass of the gear box is increase as the specified values of the reliability is increased.

  8. Optimum Stirling engine geometry

    Energy Technology Data Exchange (ETDEWEB)

    Senft, J.R. [University of Wisconsin, River Walls, WI (United States). Mathematics Dept.

    2002-07-01

    This paper combines the author's work on mechanical efficiency of reciprocating engines with the classic Schmidt thermodynamic model for Stirling engines and revisits the problem of identifying optimal engine geometry. All previous optimizations using the Schmidt theory focused on obtaining a maximal specific indicated cyclic work. This does not necessarily produce the highest shaft output. Indeed, some optima based upon indicated work would yield engines that cannot run at all due to excessive intrinsic mechanical losses. The analysis presented in this paper shows how to optimize for shaft or brake work output. Specifically, it presents solutions to the problem of finding the piston-to-displacer swept volume ratio and phase angle which will give the maximum brake output for a given total swept volume, given temperature extremes, a given mean operating pressure, and a given engine mechanism effectiveness. The paper covers the split-cylinder or gamma-type Stirling in detail, serving as a model for similar analysis of the other Stirling engine configurations. (author)

  9. The characteristics of the combustion process occurring under real operating conditions of traction

    Science.gov (United States)

    Longwic, R.; Sander, P.

    2016-09-01

    The authors deal with the issues of the Diesel engine under dynamic conditions. The conditions of the dynamic operation of the engine have most frequently been mapped by the method of free acceleration of the engine caused by the change of the position of the fuel dose lever. The article presents the results of indication of the traction Diesel engine under real operating conditions. This allows for the use of a mobile system to indicate the AVL engine built in the vehicle in research. We analysed a number of thermodynamic parameters of the combustion process in various dynamic states, typical for the process of actual operation of the engine, such as working in start-up conditions and immediately after, working in conditions of acceleration and coasting. Formulated conclusions significantly expand the area of knowledge concerning the functioning of the internal combustion engine in dynamic conditions.

  10. Operational-Condition-Independent Criteria Dedicated to Monitoring Wind Turbine Generators

    Directory of Open Access Journals (Sweden)

    Richard Court

    2013-01-01

    Full Text Available Condition monitoring is beneficial to the wind industry for both onshore and offshore plants. However, due to the variations in operational conditions, its potential has not been fully explored. There is a need to develop an operational-condition-independent condition monitoring technique, which has motivated the research presented here. In this paper, three operational-condition-independent criteria are developed. The criteria accomplish the condition monitoring by analyzing the wind turbine electrical signals in the time domain. Therefore, they are simple to calculate and ideal for online use. All proposed criteria were tested through both simulated and practical experiments. The experiments have shown that these criteria not only provide a solution for detecting both mechanical and electrical faults that occur in wind turbine generators, but provide a potential tool for diagnosing generator winding faults.

  11. Active magnetic bearings for optimum turbomachinery design

    Science.gov (United States)

    Hustak, J.; Kirk, R. G.; Schoeneck, K. A.

    1985-01-01

    The design and shop test results are given for a high speed eight stage centrifugal compressor supported by active magnetic bearings. A brief summary of the rotor dynamics analysis is presented with specific attention given to design considerations for optimum rotor stability. The concerns for retrofit of magnetic bearings in existing machinery are discussed with supporting analysis of a four stage centrifugal compressor. Recommendations are given on design and analysis requirements for successful machinery operation of either retrofit or new design turbomachinery.

  12. 应用联合分析探讨卫氏并殖吸虫囊蚴脱囊优化条件%Study on the optimum condition for decysting of Paragonimus westermani using conjoint analysis

    Institute of Scientific and Technical Information of China (English)

    曲桂玉; 杜国防; 陈景武

    2009-01-01

    目的将联合分析运用于卫氏并殖吸虫囊蚴脱囊优化条件研究中,分析囊蚴脱囊各影响因素的效用值,确定脱囊条件的最优组合.方法选定影响卫氏并殖吸虫囊蚴脱囊的4个主要因素,即在pH2的条件下的胃酶浓度、胃酶作用时间、胰酶浓度、胆盐浓度等4个因素,各取4个梯度,选用L16(45)正交表安排试验,对正交设计试验结果进行联合分析.结果卫氏并殖吸虫囊蚴脱囊影响因素的相对重要性按大小依次是胃酶浓度、胃酶作用时间、胆盐浓度、胰酶浓度,卫氏并殖吸虫囊蚴脱囊条件的最优搭配为胃酶浓度0.025%、胃酶作用时间10 min、胆盐浓度0.025%、胰酶浓度0.250%.结论联合分析可用于卫氏并殖吸虫囊蚴脱囊试验中,不同属性间可以通过成分效用值相互比较,分析结果较为直观,容易理解,显示了其在定量研究中的优势.%Objective To determine the optimum condition for decysting of Paragonimus westermani cysts by analysis of various influential factors using conjoint analysis.Methods Four main influential factors i.e.pepsin concentration,pepsin action time,pancreatin and bile salt concentration under the condition of pH2 were chosen,each factor had 4 levels.The test was performed according to the orthogonal table L16(45).Joint analysis was used for processing of the resuhs of the orthogonal test.Results The pepsin concentration was the most influential factor,pepsin action time was the second one,the bile salt concentration was the third one and pancreatin concentration was the last one for decysting of Paragonimus westermani cysts.The optimum condition was the combination of the pepsin concentration of 0.025%,the pepsin action time of 10 min,the bile salt concentration of 0.025%,and the pancreatin concentration of 0.250%.Conclusion The conjoint analysis can be applied in the study on decysting of Paragonimus westermani cysts.

  13. Matrix multiplication operations with data pre-conditioning in a high performance computing architecture

    Science.gov (United States)

    Eichenberger, Alexandre E; Gschwind, Michael K; Gunnels, John A

    2013-11-05

    Mechanisms for performing matrix multiplication operations with data pre-conditioning in a high performance computing architecture are provided. A vector load operation is performed to load a first vector operand of the matrix multiplication operation to a first target vector register. A load and splat operation is performed to load an element of a second vector operand and replicating the element to each of a plurality of elements of a second target vector register. A multiply add operation is performed on elements of the first target vector register and elements of the second target vector register to generate a partial product of the matrix multiplication operation. The partial product of the matrix multiplication operation is accumulated with other partial products of the matrix multiplication operation.

  14. A method for aggregating external operating conditions in multi-generation system optimization models

    DEFF Research Database (Denmark)

    Lythcke-Jørgensen, Christoffer Ernst; Münster, Marie; Ensinas, Adriano Viana

    2016-01-01

    This paper presents a novel, simple method for reducing external operating condition datasets to be used in multi-generation system optimization models. The method, called the Characteristic Operating Pattern (CHOP) method, is a visually-based aggregation method that clusters reference data based...... on parameter values rather than time of occurrence, thereby preserving important information on short-term relations between the relevant operating parameters. This is opposed to commonly used methods where data are averaged over chronological periods (months or years), and extreme conditions are hidden...... in the averaged values. The CHOP method is tested in a case study where the operation of a fictive Danish combined heat and power plant is optimized over a historical 5-year period. The optimization model is solved using the full external operating condition dataset, a reduced dataset obtained using the CHOP...

  15. Relative Effectiveness of Operant Conditioning and Play Therapy in Childhood Schizophrenia

    Science.gov (United States)

    Ney, Philip G.; And Others

    1971-01-01

    An experimental study designed to examine the relative effectiveness of operant conditioning and play therapy in improving the communication and social functioning of psychotic children was presented and discussed. (Author)

  16. THE MINIMAL PROPERTY OF THE CONDITION NUMBER OF INVERTIBLE LINEAR BOUNDED OPERATORS IN BANACH SPACES

    Institute of Scientific and Technical Information of China (English)

    陈果良; 魏木生

    2002-01-01

    In this paper we show that in error estimates, the condition number κ(T) of any invertible linear bounded operator T in Banach spaces is minimal. We also extend the Hahn-Banach theorem and other related results.

  17. Optimization of recirculating laminar air flow in operating room air conditioning systems

    Directory of Open Access Journals (Sweden)

    Enver Yalcin

    2016-04-01

    Full Text Available The laminar flow air-conditioning system with 100% fresh air is used in almost all operating rooms without discrimination in Turkey. The laminar flow device which is working with 100% fresh air should be absolutely used in Type 1A operating rooms. However, there is not mandatory to use of 100% fresh air for Type 1B defined as places performed simpler operation. Compared with recirculating laminar flow, energy needs of the laminar flow with 100 % fresh air has been emerged about 40% more than re-circulated air flow. Therefore, when a recirculating laminar flow device is operated instead of laminar flow system with 100% fresh air in the Type 1B operating room, annual energy consumption will be reduced. In this study, in an operating room with recirculating laminar flow, optimal conditions have been investigated in order to obtain laminar flow form by analyzing velocity distributions at various supply velocities by using computational fluid dynamics method (CFD.

  18. Effect of automobile operating condition on the subjective equivalence of steering wheel vibration and sound

    OpenAIRE

    2007-01-01

    For the manufacturers of automobiles, automobile components and fuels, subjective equivalence relationships between vibration and sound can be used as a reference against which to plot the results from simulations or tests of specific operational conditions. The research described here was performed to define curves of subjective equivalence between steering wheel rotational vibration and sound using stimuli from different automobile operating conditions. The steering wheel acceleration stimu...

  19. Zeros and poles of quantum current operators and the condition of quantum integrability

    CERN Document Server

    Ding, J; Ding, Jintai; Miwa, Tetsuji

    1996-01-01

    For the current realization of the affine quantum groups, a simple comultiplication for the quantum current operators was given by Drinfeld. With this comultiplication, we study the zeros and poles of the quantum current operators and present a condition of integrability on the quantum current of $U_q\\left(\\hat{\\frak sl}(2)\\right)$, which is a deformation of the corresponding condition for $\\hat{\\frak sl}(2)$.

  20. Control of hybrid AC/DC microgrid under islanding operational conditions

    DEFF Research Database (Denmark)

    Ding, G.; Gao, F.; Zhang, S.

    2014-01-01

    This paper presents control methods for hybrid AC/DC microgrid under islanding operation condition. The control schemes for AC sub-microgrid and DC sub-microgrid are investigated according to the power sharing requirement and operational reliability. In addition, the key control schemes......, the whole hybrid AC/DC microgrid can manage the power flow transferred between sub-microgrids for improving on the operational quality and efficiency....

  1. A Paradigm for Operant Conditioning in Blow Flies ("Phormia Terrae Novae" Robineau-Desvoidy, 1830)

    Science.gov (United States)

    Sokolowski, Michel B. C.; Disma, Gerald; Abramson, Charles I.

    2010-01-01

    An operant conditioning situation for the blow fly ("Protophormia terrae novae") is described. Individual flies are trained to enter and reenter a hole as the operant response. Only a few sessions of contingent reinforcement are required to increase response rates. When the response is no longer followed by food, the rate of entering the hole…

  2. Deficiency indices of a differential operator satisfying certain matching interface conditions

    Directory of Open Access Journals (Sweden)

    Pallav Kumar Baruah

    2005-03-01

    Full Text Available A pair of differential operators with matching interface conditions appears in many physical applications such as: oceanography, the study of step index fiber in optical fiber communication, and one dimensional scattering in quantum theory. Here we initiate the study the deficiency index theory of such operators which precedes the study of the spectral theory.

  3. Long term performance of gas-insulated switchgear operating under tropical conditions

    NARCIS (Netherlands)

    Pharmatrisanti, A.

    2012-01-01

    For the past two decades, electricity utilities have struggled to provide high quality electrical power to their customers while keeping on spending effectively the expenses for operating and maintaining the power system. Unfortunately, under tropical conditions, operation circumstances affect the e

  4. 双酶法制备小麦微孔淀粉的工艺条件优化%Optimum Preparation Conditions for Wheat Micorporous Starch by Double Enzyme Hydrolysis Method

    Institute of Scientific and Technical Information of China (English)

    张国权; 张兰月; 罗勤贵; 梅仕峰

    2013-01-01

      为丰富微孔淀粉类型、拓展小麦淀粉的应用领域,以小麦A淀粉为材料,采用α-淀粉酶与糖化酶双酶协同水解法优化小麦微孔淀粉的制备工艺条件。结果表明:影响小麦微孔淀粉吸水率的因素依次为反应温度、酶用量、反应时间和pH,影响吸油率的因素依次为反应温度、pH、反应时间和酶用量。制备小麦微孔淀粉的适宜条件为,糖化酶与α-淀粉酶的配比6∶1,淀粉乳浓度20%,反应温度55℃,酶用量1.25%,pH4.5,反应时间16 h,此条件下小麦微孔淀粉的吸水率为115.14%,吸油率为103.46%,其吸附性能远高于原淀粉。%  In order to enrich the microporous starch types and broaden the application fields of wheat starch , the wheat A type starch was used as material and the technological conditions of preparation of microporous starch using co-hydrolysis by α-amylase and glucoamylase were optimized. The results show that reaction temperature was the main factor affecting the water absorption rate of wheat microporous starch , followed by enzyme dosage, reaction time and pH value. While the oil absorption rate was in turn influenced by reaction temperature, pH value, reaction time and enzyme dosage. The optimum preparation conditions for wheat microporous starch were glucoamylase:α-amylase ratio of 6∶1, starch concentration of 20%(w/v), reaction temperature of 55℃, enzyme dosage of 1.25%, pH4.5 and reaction time of 16 h. Under the condition , water absorption rate of microporous starch was up to 115.14 %, oil absorption rate was up to 103.46 %. The absorption properties of micropous starch is higher than raw starch obviously.

  5. RP-HPLC法分离异黄酮中移动相条件的优化%Optimum of Mobile Phase Condition for Resolving Isoflavones in RP-HPLC

    Institute of Scientific and Technical Information of China (English)

    郑金珠; 盧敬昊

    2007-01-01

    In reversed-phase high performance liquid chromatography (RP-HPLC),the mobile phase condition for separating eight isoflavones (daidzin,glycitin,genistin,6'-o-acetyl daidzin,6'-o-malonyl genistin,daidzein,glycitein and genistein) was optimized using the HCI (High-Purity Separation Laboratory,Department of Chemical Engineering,Inha University) program software.The optimum composition of mobile phase for the separation of the eight isoflavones was obtained.The elution profiles were calculated by the plate theory based on the equations of retention factor,In k=A+BF+CF2,where F Was the volume percentage of acetonitrile with 0.1% acetic acid (AA).The first mobile phase composition was water with 0.1% AA/acetonitrile with 0.1% AA (88%/12%,by volume),followed at 9min later by the second composition of mobile phase which was step-changed to 85%/15%,at 19min by the third composition which was step-changed to 73%/27%,at 30min when it was changed to 65%/35% and finally it was maintained in isocratic mode to the end of the run time at 50min.Although,using step gradient mode to separate the isoflavones,the calculated and experimented data were not achieved very good agwement,we could estimate the closed retention time before experiment.And the agreement between the experimental data and the calculated values was relatively good using isocratic separation for eight isoflavones,but the retention time is very long.

  6. Non-trapping condition for semiclassical Schr dinger operators with matrix-valued potentials.

    CERN Document Server

    Jecko, T

    2004-01-01

    We consider semiclassical Schr dinger operators with matrix-valued, long-range, smooth potential, for which different eigenvalues may cross on a codimension one submanifold. We denote by h the semiclassical parameter and we consider energies above the bottom of the essential spectrum. Under some invariance condition on the matricial structure of the potential near the eigenvalues crossing and some structure condition at infinity, we prove that the boundary values of the resolvent at energy lambda, as bounded operators on suitable weighted spaces, are O(1/h) if and only if lambda is a non-trapping energy for all the Hamilton flows generated by the eigenvalues of the operator's symbol.

  7. Pre-Swirl Stator and Propeller Design for Varying Operating Conditions

    DEFF Research Database (Denmark)

    Saettone, Simone; Regener, Pelle Bo; Andersen, Poul

    2016-01-01

    blades ahead of the propeller.This paper describes the hydrodynamic design of apre-swirl stator with radially variable pitch, paired with aconventional propeller. The aim is to achieve the highest possible effciency in various operating conditions, and to avoid effciency penalties in off-design operation.......To investigate the propeller and stator designs and configurations in different operating conditions, the computationally inexpensive vortex-lattice method is used a sa first step to optimize the geometry in an initial parameter study. Then the flow over hull, stator and propelleris simulated in a CFD...

  8. Feeding Behavior of Aplysia: A Model System for Comparing Cellular Mechanisms of Classical and Operant Conditioning

    Science.gov (United States)

    Baxter, Douglas A.; Byrne, John H.

    2006-01-01

    Feeding behavior of Aplysia provides an excellent model system for analyzing and comparing mechanisms underlying appetitive classical conditioning and reward operant conditioning. Behavioral protocols have been developed for both forms of associative learning, both of which increase the occurrence of biting following training. Because the neural…

  9. Contriving Transitive Conditioned Establishing Operations to Establish Derived Manding Skills in Adults with Severe Developmental Disabilities

    Science.gov (United States)

    Rosales, Rocio; Rehfeldt, Ruth Anne

    2007-01-01

    The purpose of this study was to demonstrate derived manding skills in 2 adults with severe developmental disabilities and language deficits by contriving transitive conditioned establishing operations. Specifically, we evaluated whether a history of reinforced conditional discrimination learning would ultimately result in a derived mand…

  10. Design of optimal operating conditions of simulated moving bed adsorptive separation units

    Energy Technology Data Exchange (ETDEWEB)

    Storti, G. (Univ. degli Studi di Padova (Italy)); Baciocchi, R.; Mazzotti, M.; Morbidelli, M. (Politecnico di Milano (Italy). Dipt. di Chimica Fisica Applicata)

    1995-01-01

    The design of the optimal operating conditions for simulated moving bed (SMB) adsorptive separation units is considered. A procedure for the a priori selection of the operating conditions to achieve an assigned separation requirement is developed in the frame of equilibrium theory for the equivalent four section countercurrent unit, using a model where the adsorption equilibria are described through the constant selectivity stoichiometric model, while both mass transfer resistance and axial dispersion are neglected. The space of the operating parameters, i.e. the mass flow rate ratios m[sub j], is divided in regions with different separation regimes. Curves at constant outlets purity and recovery are drawn in the (m[sub 2],m[sub 3]) plane. The introduction of three performance parameters, desorbent requirement, adsorbent requirement, and productivity, allows the development of a procedure for the design of optimal operating conditions. This procedure is completed, accounting for the effect of the switching time on the separation performances, with a detailed model of the SMB unit, considering both axial dispersion and mass transfer resistance. This result constitutes a useful tool for determining the range of operating conditions to achieve an assigned separation requirement and then for selecting the optimal operating condition within this range.

  11. Analysis and discretization of the volume penalized Laplace operator with Neumann boundary conditions

    CERN Document Server

    Kolomenskiy, Dmitry; Schneider, Kai

    2014-01-01

    We study the properties of an approximation of the Laplace operator with Neumann boundary conditions using volume penalization. For the one-dimensional Poisson equation we compute explicitly the exact solution of the penalized equation and quantify the penalization error. Numerical simulations using finite differences allow then to assess the discretisation and penalization errors. The eigenvalue problem of the penalized Laplace operator with Neumann boundary conditions is also studied. As examples in two space dimensions, we consider a Poisson equation with Neumann boundary conditions in rectangular and circular domains.

  12. Many-body position operator in lattice fermionic systems with periodic boundary conditions

    Energy Technology Data Exchange (ETDEWEB)

    Hetenyi, Balazs [Institut fuer Theoretische Physik, Technische Universitaet Graz, Petersgasse 16, A-8010 Graz (Austria); Mathematisches Institut, Fakultaet fuer Mathematik, Informatik und Statistik, Ludwig Maximilians Universitaet, Theresienstrasse 39, Muenchen 80333 (Germany)], E-mail: hetenyi@itp.tugraz.at

    2009-10-16

    A total position operator X in the position representation is derived for lattice fermionic systems with periodic boundary conditions. The operator is shown to be Hermitian, the generator of translations in momentum space, and its time derivative is shown to correspond to the total current operator in a periodic system. The operator is such that its moments can be calculated up to any order. To demonstrate its utility finite size scaling is applied to the Brinkman-Rice transition as well as to metallic and insulating Gutzwiller wavefunctions. (fast track communication)

  13. Fluid dynamic characterization of operating conditions for continuous flow blood pumps.

    Science.gov (United States)

    Wu, Z J; Antaki, J F; Burgreen, G W; Butler, K C; Thomas, D C; Griffith, B P

    1999-01-01

    As continuous flow pumps become more prominent as long-term ventricular assist devices, the wide range of conditions under which they must be operated has become evident. Designed to operate at a single, best-efficiency, operating point, continuous flow pumps are required to perform at off-design conditions quite frequently. The present study investigated the internal fluid dynamics within two representative rotary fluid pumps to characterize the quality of the flow field over a full range of operating conditions. A Nimbus/UoP axial flow blood pump and a small centrifugal pump were used as the study models. Full field visualization of flow features in the two pumps was conducted using a laser based fluorescent particle imaging technique. Experiments were performed under steady flow conditions. Flow patterns at inlet and outlet sections were visualized over a series of operating points. Flow features specific to each pump design were observed to exist under all operating conditions. At off-design conditions, an annular region of reverse flow was commonly observed within the inlet of the axial pump, while a small annulus of backflow in the inlet duct and a strong disturbed flow at the outlet tongue were observed for the centrifugal pump. These observations were correlated to a critical nondimensional flow coefficient. The creation of a "map" of flow behavior provides an additional, important criterion for determining favorable operating speed for rotary blood pumps. Many unfavorable flow features may be avoided by maintaining the flow coefficient above a characteristic critical coefficient for a particular pump, whereas the intrinsic deleterious flow features can only be minimized by design improvement. Broadening the operating range by raising the band between the critical flow coefficient and the designed flow coefficient, is also a worthy goal for design improvement.

  14. 纤维素酶产生菌的鉴定及其混合发酵条件优化%Study on Identification of Cellulose-Decomposing Microorganisms and Optimum Conditions for Their Mixed Cultivation

    Institute of Scientific and Technical Information of China (English)

    卢月霞; 刘凯楠; 李翠萍

    2011-01-01

    Four strains of microbes with relatively high cellulase activity named as D6, D7, B7 and D1 were selected; and primarily identified as 3 bacteria and one actinomyces.Based on the results of 16S rDNA sequencing, the homology among strains D6, D7, B7 and Bacillus sp.were 99%; and between D1 and Streptomyces zaomyceticus was also 99%.The phyloge netic tree built on the 16S rDNA sequence indicated that the former three strains had the nearest relationship with Bacillus sp., while the latter one was nearest to S.zaomyceticus.Enzyme activity of mixed strain D6/D7 was obviously higher than that of single strain.The optimum enzyme-producing conditions were at 37℃, with medium primary pH 8.0, 2% of inocula tion(V/V), and inoculation proportion D6∶D7 at 2∶1.Under these conditions, the enzyme activity reached 79.42 U/mL.%分离筛选到的4株纤维素酶活较高的菌株D6、D7、B7和D1,根据形态特征初步判断为3株细菌、1株放线菌,其16S rDNA序列同源性分析结果发现D6、D7、B7与Bacillus sp.的同源性为99%,系统发育树分析与Bacillus sp.遗传关系最近,D1与Streptomyces zaomyceticus的同源性为99%,系统发育树分析与Streptomyces zaomyceticus遗传关系最近;对4株菌株进行单独与混合发酵培养,结果表明菌株组合D6/D7混合培养后的酶活显著高于其单菌培养,其在培养温度37℃、培养基初始pH值为8.0、接种量为2%(V/V)、D6/D7接种比例为2:1(V:V)下的酶活最高,可达到79.42U/mL.

  15. 石榴皮和松子壳中抑菌物质最佳提取条件的研究%Study on Optimum Extraction Conditions of Antibacterial Substance fromPericarpium Granati and Pine Nut Shell

    Institute of Scientific and Technical Information of China (English)

    付荣霞; 崔艳; 杨树成; 王佳玮

    2015-01-01

    Objective To optimize the extraction conditions of mixture ofPericarpium Granati and pine nut shells, with the ratio ofPericarpium Granati to pine nut shells, ratio of material to liquid, extraction temperature and extraction time as selecting factors, using water as extraction solvent.Methods Oxford cup method and double medium have been used during the experiment to measure the inhibitory effect of the extract ofPericarpium Granati and pine nut shells onEscherichia coli andBacillus subtilis.Results The optimum extraction conditions were as follows: ratio of Pericarpium Granati to pine nut shells of 3:1, ratio of material to liquid of 1:5, extraction temperature of 50℃, and extraction time of 4 h. Conclusion The study can provide the theoretical basis for the application of the antibacterial extract as a natural food preservative .%目的:以水为浸提溶剂,选择不同的石榴皮和松子壳比例、料液比、提取温度和时间4个因素进行试验,研究石榴皮和松子壳中抑菌物质的最佳提取条件。方法采用牛津杯法,设置双层培养基,通过测量抑菌圈直径研究石榴皮和松子壳混合提取液对大肠杆菌(革兰阴性菌)和枯草芽孢杆菌(革兰阳性菌)的抑制作用。结果石榴皮和松子壳中抑菌物质的最佳提取条件为:石榴皮和松子壳的比例3:1、料液比1:5、温度50℃、提取时间4 h。结论石榴皮和松子壳提取物有一定的抑菌效果,将其作为天然防腐剂应用于食品是可行的。

  16. Determination of Initial Conditions for the Safety Analysis by Random Sampling of Operating Parameters

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hae-Yong; Park, Moon-Ghu [Sejong University, Seoul (Korea, Republic of)

    2015-05-15

    In most existing evaluation methodologies, which follow a conservative approach, the most conservative initial conditions are searched for each transient scenario through tremendous assessment for wide operating windows or limiting conditions for operation (LCO) allowed by the operating guidelines. In this procedure, a user effect could be involved and a remarkable time and human resources are consumed. In the present study, we investigated a more effective statistical method for the selection of the most conservative initial condition by the use of random sampling of operating parameters affecting the initial conditions. A method for the determination of initial conditions based on random sampling of plant design parameters is proposed. This method is expected to be applied for the selection of the most conservative initial plant conditions in the safety analysis using a conservative evaluation methodology. In the method, it is suggested that the initial conditions of reactor coolant flow rate, pressurizer level, pressurizer pressure, and SG level are adjusted by controlling the pump rated flow, setpoints of PLCS, PPCS, and FWCS, respectively. The proposed technique is expected to contribute to eliminate the human factors introduced in the conventional safety analysis procedure and also to reduce the human resources invested in the safety evaluation of nuclear power plants.

  17. TRUNK WITH BRANCHES PUBLIC TRANSPORT LINE SCHEDULLING UNDER CONDITION OF UNIFORM HEADWAY OPERATION

    Directory of Open Access Journals (Sweden)

    Nikola Krstanoski

    2015-12-01

    Full Text Available Planning of public transport network for good spatial coverage may lead to an operation of radial or diametrical public transport lines that branch at one or both ends of the line. This trunk with branches operation means that all vehicles on the line serve the main - trunk section, usually covering the central area of the city, and then split in two or more branches in the peripheral areas, in order to offer better spatial service. The scheduling of this type of operation is not an easy task since only certain patterns of headways and therefore passenger demands can be met, if efficient operation under the condition of uniform headways on all sections on the line is required. In this article the author analyzes the key variables that define the uniform headway operation and establishes their relationships, thus providing answer to the question what headway patterns are feasible and if they could be acceptable for real life operation.

  18. Performance of diagonal control structures at different operating conditions for polymer electrolyte membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Serra, Maria; Husar, Attila; Feroldi, Diego; Riera, Jordi [Institut de Robotica i Informatica Industrial, Universitat Politecnica de Catalunya, Consejo Superior de Investigaciones Cientificas, C. Llorens i Artigas 4, 08028 Barcelona (Spain)

    2006-08-25

    This work is focused on the selection of operating conditions in polymer electrolyte membrane fuel cells. It analyses efficiency and controllability aspects, which change from one operating point to another. Specifically, several operating points that deliver the same amount of net power are compared, and the comparison is done at different net power levels. The study is based on a complex non-linear model, which has been linearised at the selected operating points. Different linear analysis tools are applied to the linear models and results show important controllability differences between operating points. The performance of diagonal control structures with PI controllers at different operating points is also studied. A method for the tuning of the controllers is proposed and applied. The behaviour of the controlled system is simulated with the non-linear model. Conclusions indicate a possible trade-off between controllability and optimisation of hydrogen consumption. (author)

  19. The theoretical analysis and experimental research on the optimal condition of semiconductor refrigeration

    Science.gov (United States)

    Pang, Y. F.

    2016-08-01

    The traditional limiting conditions have the biggest refrigeration quantity condition and the biggest refrigeration coefficient condition, there is a special operating mode during these conditions, enabling to both have the big refrigeration quantity and the small power loss, this operating mode is “Optimum condition”. This article first carried on the theoretical analysis to the semiconductor's optimum condition, inferred optimum electric current's theoretical formula; Carried on the experiment again to a semiconductor refrigeration box by regulating current changing operating mode, which had analyzed performance parameter's change situation under 8 kinds of condition experiments, carried on the regression analysis to the experimental data, obtained the regression equation thus discovered optimum electric current corresponding optimum condition. Carried on working under this condition, and then obtained the big refrigeration quantity and small power, which enhanced the refrigeration performance of semiconductor refrigerator. The experimental result and the theoretical analysis result tallied basically.

  20. Detection and classification of alarm threshold violations in condition monitoring systems working in highly varying operational conditions

    Science.gov (United States)

    Strączkiewicz, M.; Barszcz, T.; Jabłoński, A.

    2015-07-01

    All commonly used condition monitoring systems (CMS) enable defining alarm thresholds that enhance efficient surveillance and maintenance of dynamic state of machinery. The thresholds are imposed on the measured values such as vibration-based indicators, temperature, pressure, etc. For complex machinery such as wind turbine (WT) the total number of thresholds might be counted in hundreds multiplied by the number of operational states. All the parameters vary not only due to possible machinery malfunctions, but also due to changes in operating conditions and these changes are typically much stronger than the former ones. Very often, such a behavior may lead to hundreds of false alarms. Therefore, authors propose a novel approach based on parameterized description of the threshold violation. For this purpose the novelty and severity factors are introduced. The first parameter refers to the time of violation occurrence while the second one describes the impact of the indicator-increase to the entire machine. Such approach increases reliability of the CMS by providing the operator with the most useful information of the system events. The idea of the procedure is presented on a simulated data similar to those from a wind turbine.

  1. Optimum Process Conditions and Reaction Mechanism of Preparing Mo2C Catalyst%制备Mo2C催化剂的最佳工艺条件及其反应机理

    Institute of Scientific and Technical Information of China (English)

    张建明; 张晓彤; 宋丽娟; 孙兆林; 刘丽莉

    2011-01-01

    Molybdenum trioxide as precursor was prepared by roasting ammonium molybdate. Then using molybdenum trioxide and the gas mixture of H2 and CH4 as raw materials .molybdenum carbide was prepared by the temperature-programmed reaction method.The best temperature of preparing molybdenum trioxide from ammonium molybdate was investigated as well as the best ratio of H2 to CH4 and terminal temperature in the temperature-programmed reaction; the final product was characterized by X-ray diffraction.The results show that the optimum process conditions for the reaction: roasting temperature is at 450 °C, V(H2)V(CH4) is in the range of 2 : 1 ~ 4 : 1, the final temperature of carbonization is at 700 °C; the reaction mechanism: firstly, MoO3 is reduced to MoO2, then MoO2 must be reduced to transition state Mo, finally Mo2C is gained.%钼酸铵焙烧制备碳化钼前驱体MoO3,以MoO3为钼源、V(H2)/V(CH4)混合气体为碳化介质采用程序升温反应法制备Mo2C催化剂;考察钼酸铵制备.MoO3适宜的温度,以及程序升温反应法制备Mo2C的最适V(H2)/V(CH4)比和碳化终温,用XRD表征分析产物。得出制备Mo2C催化剂的最佳工艺条件是:钼酸铵焙烧温度为450℃、V(H/V(CH4)为2:1~4:1、碳化终温为700℃;其反应机理是:MoO3先被还原为MoO2,MoO2需经历过渡态的单质Mo才能碳化生成Mo2C。

  2. Significance of Operating Environment in Condition Monitoring of Large Civil Structures

    Directory of Open Access Journals (Sweden)

    Sreenivas Alampalli

    1999-01-01

    Full Text Available Success of remote long-term condition monitoring of large civil structures and developing calibrated analytical models for damage detection, depend significantly on establishing accurate baseline signatures and their sensitivity. Most studies reported in the literature concentrated on the effect of structural damage on modal parameters without emphasis on reliability of modal parameters. Thus, a field bridge structure was studied for the significance of operating conditions in relation to baseline signatures. Results indicate that in practice, civil structures should be monitored for at least one full cycle of in-service environmental changes before establishing baselines for condition monitoring or calibrating finite-element models. Boundary conditions deserve special attention.

  3. Classifier-ensemble incremental-learning procedure for nuclear transient identification at different operational conditions

    Energy Technology Data Exchange (ETDEWEB)

    Baraldi, Piero, E-mail: piero.baraldi@polimi.i [Dipartimento di Energia - Sezione Ingegneria Nucleare, Politecnico di Milano, via Ponzio 34/3, 20133 Milano (Italy); Razavi-Far, Roozbeh [Dipartimento di Energia - Sezione Ingegneria Nucleare, Politecnico di Milano, via Ponzio 34/3, 20133 Milano (Italy); Zio, Enrico [Dipartimento di Energia - Sezione Ingegneria Nucleare, Politecnico di Milano, via Ponzio 34/3, 20133 Milano (Italy); Ecole Centrale Paris-Supelec, Paris (France)

    2011-04-15

    An important requirement for the practical implementation of empirical diagnostic systems is the capability of classifying transients in all plant operational conditions. The present paper proposes an approach based on an ensemble of classifiers for incrementally learning transients under different operational conditions. New classifiers are added to the ensemble where transients occurring in new operational conditions are not satisfactorily classified. The construction of the ensemble is made by bagging; the base classifier is a supervised Fuzzy C Means (FCM) classifier whose outcomes are combined by majority voting. The incremental learning procedure is applied to the identification of simulated transients in the feedwater system of a Boiling Water Reactor (BWR) under different reactor power levels.

  4. Assessment of biogas production from MBT waste under different operating conditions

    DEFF Research Database (Denmark)

    Pantini, Sara; Verginelli, Jason; Lombardi, Francesco;

    2015-01-01

    In this work, the influence of different operating conditions on the biogas production from mechanically-. biologically treated (MBT) wastes is investigated. Specifically, different lab-scale anaerobic tests varying the water content (26-43% w/w up to 75% w/w), the temperature (from 20 to 25......, the obtained results highlighted that the operative conditions can drastically affect the gas production from MET wastes. This suggests that particular caution should be paid when using the results of lab-scale tests for the evaluation of long-term behaviour expected in the field where the boundary conditions...... change continuously and vary significantly depending on the climate, the landfill operative management strategies in place (e.g. leachate recirculation, waste disposal methods), the hydraulic characteristics of disposed waste, the presence and type of temporary and final cover systems. (C) 2015 Elsevier...

  5. Identifying the microbial communities and operational conditions for optimized wastewater treatment in microbial fuel cells.

    Science.gov (United States)

    Ishii, Shun'ichi; Suzuki, Shino; Norden-Krichmar, Trina M; Wu, Angela; Yamanaka, Yuko; Nealson, Kenneth H; Bretschger, Orianna

    2013-12-01

    Microbial fuel cells (MFCs) are devices that exploit microorganisms as "biocatalysts" to recover energy from organic matter in the form of electricity. MFCs have been explored as possible energy neutral wastewater treatment systems; however, fundamental knowledge is still required about how MFC-associated microbial communities are affected by different operational conditions and can be optimized for accelerated wastewater treatment rates. In this study, we explored how electricity-generating microbial biofilms were established at MFC anodes and responded to three different operational conditions during wastewater treatment: 1) MFC operation using a 750 Ω external resistor (0.3 mA current production); 2) set-potential (SP) operation with the anode electrode potentiostatically controlled to +100 mV vs SHE (4.0 mA current production); and 3) open circuit (OC) operation (zero current generation). For all reactors, primary clarifier effluent collected from a municipal wastewater plant was used as the sole carbon and microbial source. Batch operation demonstrated nearly complete organic matter consumption after a residence time of 8-12 days for the MFC condition, 4-6 days for the SP condition, and 15-20 days for the OC condition. These results indicate that higher current generation accelerates organic matter degradation during MFC wastewater treatment. The microbial community analysis was conducted for the three reactors using 16S rRNA gene sequencing. Although the inoculated wastewater was dominated by members of Epsilonproteobacteria, Gammaproteobacteria, and Bacteroidetes species, the electricity-generating biofilms in MFC and SP reactors were dominated by Deltaproteobacteria and Bacteroidetes. Within Deltaproteobacteria, phylotypes classified to family Desulfobulbaceae and Geobacteraceae increased significantly under the SP condition with higher current generation; however those phylotypes were not found in the OC reactor. These analyses suggest that species

  6. Operational Meanings of Orders of Observables Defined through Quantum Set Theories with Different Conditionals

    Directory of Open Access Journals (Sweden)

    Masanao Ozawa

    2017-01-01

    Full Text Available In quantum logic there is well-known arbitrariness in choosing a binary operation for conditional. Currently, we have at least three candidates, called the Sasaki conditional, the contrapositive Sasaki conditional, and the relevance conditional. A fundamental problem is to show how the form of the conditional follows from an analysis of operational concepts in quantum theory. Here, we attempt such an analysis through quantum set theory (QST. In this paper, we develop quantum set theory based on quantum logics with those three conditionals, each of which defines different quantum logical truth value assignment. We show that those three models satisfy the transfer principle of the same form to determine the quantum logical truth values of theorems of the ZFC set theory. We also show that the reals in the model and the truth values of their equality are the same for those models. Interestingly, however, the order relation between quantum reals significantly depends on the underlying conditionals. We characterize the operational meanings of those order relations in terms of joint probability obtained by the successive projective measurements of arbitrary two observables. Those characterizations clearly show their individual features and will play a fundamental role in future applications to quantum physics.

  7. Altitude Performance of Modified J71 Afterburner with Revised Engine Operating Conditions

    Science.gov (United States)

    Useller, James W.; Russey, Robert E.

    1955-01-01

    An investigation was conducted in an altitude test chamber at the NACA Lewis laboratory to determine the effect of a revision of the rated engine operating conditions and modifications to the afterburner fue1 system, flameholder, and shell cooling on the augmented performance of the J71-A-2 (x-29) turbo jet engine operating at altitude . The afterburner modifications were made by the manufacturer to improve the endurance at sea-level, high-pressure conditions and to reduce the afterburner shell temperatures. The engine operating conditions of rated rotational speed and turbine-outlet gas temperature were increased. Data were obtained at conditions simulating flight at a Mach number of 0.9 and at altitudes from 40,000 to 60,000 feet. The afterburner modifications caused a reduction in afterburner combustion efficiency. The increase in rated engine speed and turbine-outlet temperature coupled with the afterburner modifications resulted in the over-all thrust of the engine and afterburner being unchanged at a given afterburner equivalence ratio, while the specific fuel consumption was increased slightly. A moderate shift in the range of equivalence ratios over which the afterburner would operate was encountered, but the maximum operable altitude remained unaltered. The afterburner-shell temperatures were also slightly reduced because of the modifications to the afterburner.

  8. Optimum Safety Levels for Breakwaters

    DEFF Research Database (Denmark)

    Burcharth, H. F.; Sørensen, John Dalsgaard

    2005-01-01

    Optimum design safety levels for rock and cube armoured rubble mound breakwaters without superstructure are investigated by numerical simulations on the basis of minimization of the total costs over the service life of the structure, taking into account typical uncertainties related to wave stati...

  9. Operational condition of direct single-mode-fiber coupled FSO terminal under strong atmospheric turbulence

    Science.gov (United States)

    Arimoto, Yoshinori

    2011-03-01

    This paper discusses the operational condition for direct single-mode-fiber-coupling FSO terminals under the various adverse weather conditions, such as strong atmospheric turbulences and rain falls. A good correlation between the scintillation index of the intensities of beacon receiving power and the signal fading depth has been observed, which allows us to predict the signal link quality based on the beacon scintillation index provided by the classical scintillation theory and concludes that the scintillation index for the beacon beam should be less than 0.1. This paper also reports the effect of performance enhancements provided by the new adaptive controller for the stable and robust terminal operation.

  10. Towards energy efficient operation of Heating, Ventilation and Air Conditioning systems via advanced supervisory control design

    Science.gov (United States)

    Oswiecinska, A.; Hibbs, J.; Zajic, I.; Burnham, K. J.

    2015-11-01

    This paper presents conceptual control solution for reliable and energy efficient operation of heating, ventilation and air conditioning (HVAC) systems used in large volume building applications, e.g. warehouse facilities or exhibition centres. Advanced two-level scalable control solution, designed to extend capabilities of the existing low-level control strategies via remote internet connection, is presented. The high-level, supervisory controller is based on Model Predictive Control (MPC) architecture, which is the state-of-the-art for indoor climate control systems. The innovative approach benefits from using passive heating and cooling control strategies for reducing the HVAC system operational costs, while ensuring that required environmental conditions are met.

  11. Methodology for selection of attributes and operating conditions for SVM-Based fault locator's

    Directory of Open Access Journals (Sweden)

    Debbie Johan Arredondo Arteaga

    2017-01-01

    Full Text Available Context: Energy distribution companies must employ strategies to meet their timely and high quality service, and fault-locating techniques represent and agile alternative for restoring the electric service in the power distribution due to the size of distribution services (generally large and the usual interruptions in the service. However, these techniques are not robust enough and present some limitations in both computational cost and the mathematical description of the models they use. Method: This paper performs an analysis based on a Support Vector Machine for the evaluation of the proper conditions to adjust and validate a fault locator for distribution systems; so that it is possible to determine the minimum number of operating conditions that allow to achieve a good performance with a low computational effort. Results: We tested the proposed methodology in a prototypical distribution circuit, located in a rural area of Colombia. This circuit has a voltage of 34.5 KV and is subdivided in 20 zones. Additionally, the characteristics of the circuit allowed us to obtain a database of 630.000 records of single-phase faults and different operating conditions. As a result, we could determine that the locator showed a performance above 98% with 200 suitable selected operating conditions. Conclusions: It is possible to improve the performance of fault locators based on Support Vector Machine. Specifically, these improvements are achieved by properly selecting optimal operating conditions and attributes, since they directly affect the performance in terms of efficiency and the computational cost.

  12. 4th International Conference on Condition Monitoring of Machinery in Non-Stationary Operations

    CERN Document Server

    Zimroz, Radoslaw; Bartelmus, Walter; Haddar, Mohamed

    2016-01-01

    The book provides readers with a snapshot of recent research and technological trends in the field of condition monitoring of machinery working under a broad range of operating conditions. Each chapter, accepted after a rigorous peer-review process, reports on an original piece of work presented and discussed at the 4th International Conference on Condition Monitoring of Machinery in Non-stationary Operations, CMMNO 2014, held on December 15-16, 2014, in Lyon, France. The contributions have been grouped into three different sections according to the main subfield (signal processing, data mining, or condition monitoring techniques) they are related to. The book includes both theoretical developments as well as a number of industrial case studies, in different areas including, but not limited to: noise and vibration; vibro-acoustic diagnosis; signal processing techniques; diagnostic data analysis; instantaneous speed identification; monitoring and diagnostic systems; and dynamic and fault modeling. This book no...

  13. 20 CFR 662.430 - Under what conditions may One-Stop operators designated to operate in a One-Stop delivery system...

    Science.gov (United States)

    2010-04-01

    ... designated to operate in a One-Stop delivery system established prior to the enactment of WIA be designated... DESCRIPTION OF THE ONE-STOP SYSTEM UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT One-Stop Operators § 662.430 Under what conditions may One-Stop operators designated to operate in a One-Stop delivery system...

  14. 反渗透膜处理维生素C凝结水的最优工艺条件%Optimum technological conditions of reverse osmosis processing VC condensation water

    Institute of Scientific and Technical Information of China (English)

    肖入峰; 刘景洋; 张建强

    2012-01-01

    Problems in the condensate water of vitamin C production project, such as its large amount, diffi- culties in disposal, storage and transport and low nutrients were analyzed in this paper, and the reverse osmosis technology was put forward accordingly. Through setting up the small sale pilot of reverse osmosis technology e- quipment and adopting the dimensionless multiple regression analysis method, relationship between operating con- ditions index and permeate water evaluation index was analyzed based on the batch experiments, the degree of the operating conditions index impacting on the permeate water evaluation indexes was quantitatively evaluated, and based on this research the optimal process parameters of the operating conditions were studied. The results show that the dimensionless multiple regression analysis method is practical and effective. In the range of orthogonal experi- ment design level, the operation pressure, pH and reflux ratio are all remarkable influencing factors of the multi-target system, and the sequence of influence degree size is :pressure 〉 pH 〉 reflux ratio 〉 temperature ,and the percentages of each factor are 43.02%, 29.01%, 25.07% and 2.89%, respectively. The influence of each operation index on the system is independent. If not to consider the membrane pollution but only the system benefits, the optimal operating conditions are temperature of 30.65℃, pressure of 1.5 MPa, reflux ratio of 0.78 and pH of 7. 475.%针对维生素C生产工艺中产生的凝结水产量大、处理成本高、存储运输困难和营养物质含量偏低等问题,采用反渗透技术对VC凝结水进行处理。实验建立小试规模反渗透膜处理装置,采用无量纲化多元回归分析方法,分析了操作条件指标与渗透水评价指标两套指标体系之间的关系,定量评价了各个操作条件指标对渗透水评价指标的整体影响程度,并在此基础上研究了最佳操作条件的工艺参数。结

  15. A hydrodynamic optimization design methodology for a ship bulbous bow under multiple operating conditions

    OpenAIRE

    Yu Lu; Xin Chang; An-kang Hu

    2016-01-01

    The main objective of this article is to describe an innovative methodology for the hydrodynamic optimization of a ship bulbous bow which considers multiple operating conditions. The proposed method is more practical and effective than the traditional optimization process, which is only based on contractually specified design condition. Parametric form approaches are adopted by employing an F-spline curve in order to generate variants of the hull bulbous bow forms using form design parameters...

  16. New oil condition monitoring system, Wearsens® enables continuous, online detection of critical operating conditions and wear damage

    Directory of Open Access Journals (Sweden)

    Manfred Mauntz

    2015-12-01

    Full Text Available A new oil sensor system is presented for the continuous, online measurement of the wear in turbines, industrial gears, generators, hydraulic systems and transformers. Detection of change is much earlier than existing technologies such as particle counting, vibration measurement or recording temperature. Thus targeted, corrective procedures and/or maintenance can be carried out before actual damage occurs. Efficient machine utilization, accurately timed preventive maintenance, increased service life and a reduction of downtime can all be achieved. The presented sensor system effectively controls the proper operation conditions of bearings and cogwheels in gears. The online diagnostics system measures components of the specific complex impedance of oils. For instance, metal abrasion due to wear debris, broken oil molecules, forming acids or oil soaps, result in an increase of the electrical conductivity, which directly correlates with the degree of contamination of the oil. For additivated lubricants, the stage of degradation of the additives can also be derived from changes in the dielectric constant. The determination of impurities or reduction in the quality of the oil and the quasi continuous evaluation of wear and chemical aging follow the holistic approach of a real-time monitoring of an alteration in the condition of the oil-machine system. Once the oil condition monitoring sensors are installed on the wind turbine, industrial gearbox and test stands, the measuring data can be displayed and evaluated elsewhere. The signals are transmitted to a web-based condition monitoring system via LAN, WLAN or serial interfaces of the sensor unit. Monitoring of the damage mechanisms during proper operation below the tolerance limits of the components enables specific preventive maintenance independent of rigid inspection intervals.

  17. A Formulation of Asymptotic and Exact Boundary Conditions Using Local Operators

    Science.gov (United States)

    Hagstrom, T.; Hariharan, S. I.

    1998-01-01

    In this paper we describe a systematic approach for constructing asymptotic boundary conditions for isotropic wave-like equations using local operators. The conditions take a recursive form with increasing order of accuracy. In three dimensions the recursion terminates and the resulting conditions are exact for solutions which are described by finite combinations of angular spherical harmonics. First, we develop the expansion for the two-dimensional wave equation and construct a sequence of easily implementable boundary conditions. We show that in three dimensions and analogous conditions are again easily implementable in addition to being exact. Also, we provide extensions of these ideas to hyperbolic systems. Namely, Maxwell's equations for TM waves are used to demonstrate the construction. Finally, we provide numerical examples to demonstrate the effectiveness of these conditions for a model problem governed by the wave equation.

  18. 低碳源城市污水厂碳源优化利用运行模式研究%Research on the Optimum Operation Strategy for Deficient Carbon Source Urban Sewage Treatment Plants

    Institute of Scientific and Technical Information of China (English)

    付国楷; 张春玲; 喻晓琴; 张智; 周琪

    2012-01-01

    采用中试规模试验,利用物质平衡分析方法,追踪碳源在各个季节不同工艺条件下的分配和利用情况,以求掌握控制碳源分配的关键性参数,从而建立基于碳源利用的污水厂优化运行模式.在原水年均COD,NH4--N,TN和TP浓度分别为129,25.6,31.5和3.38 mg/L,C/N值和C/P值分别为4.3和39.5的条件下,冬季宜采用倒置A2/O工艺,春季宜选用改良型A2/O工艺,夏季宜选用预缺氧+倒置A2/O工艺,秋季宜选用低氧/常氧交替的预缺氧+倒置A2/O工艺,此时出水带走的COD占系统输入总量的26.1%~29.4%,同化COD比例为27.5%~36.2%,直接好氧氧化的COD比例为4%~22.2%,用于反硝化脱氮的COD比例为14.8%~33.6%,用于聚磷菌超量储磷的COD比例为3.05%~6.9%,出水除总磷指标外,可以达到GB 18918-2002一级B标准.碳源分配的优劣可以作为污水厂工艺筛选和参数调整的重要依据.%Analytical methods based on mass balance were adopted in the experiment to trace the carbon source distributed and utilized in a pilot scale system. The key parameters of carbon source distribution were investigated and the optimum operation strategy for urban sewage treatment plants was built. In the conditons that the influent concentration of the COD, NH4+ -N, TN and TP were 129 mg/L,25. 6 mg/L, 31. 5 mg/L and 3. 38 mg/L, respectively, and the C/N and C/P value were 4. 3 and 39. 5, inverted AVO process was recommended in winter period, enhanced A2/O process was recommended in spring period, pre-anoxic inverted A2/O process was recommended in summer period and alternating oxygen concentration inverted A2/O process was appropriate in autumn period. In this case, the ratio of effluent COD to in-flunent COD was 26. 1%~29. 4%, the ratio of assimilating COD was 27. 5%~36. 2%, the ratio of directly oxidating COD was 4%~22. 2% , the ratio of denitrificating COD was 14. 8%~33. 6% , and the ratio of COD utilizing for removal was 3. 05%~6. 9

  19. Computer-aided decision-making aids for correcting impermissible operating conditions in electricity transmission networks; Rechnergestuetzte Entscheidungshilfen zur Korrektur unzulaessiger Betriebszustaende in elektrischen Energieuebertragungsnetzen

    Energy Technology Data Exchange (ETDEWEB)

    Werdelmann, T.

    1992-04-23

    Remedying impermissible operating conditions is particularly important in controlling electricity transmission networks. In contrast to normal operation of a network, where intervention in operation is done by the switching engineer in a central network control room with the aim of optimum economic operation of the network, which can usually be planned in advance and is done without time pressure, after the occurrence of impermissible operating conditions there is a need for quick corrective measures, in order to prevent a further worsening of network safety because of the danger of possible consequences, possibly caused by the triggering of protective devices. In spite of the increasing equipment of central network control rooms with powerful process computers, there is still a lack of quick computer-aided decision-making aids for network correction and optimisation. The aim of this work was therefore to supply quick calculation processes, which are especially suitable for aiding the switching engineer in looking for remedial measures for remedying impermissible operating conditions. (orig.) [Deutsch] Bei der Fuehrung elektrischer Energieuebertragungsnetze kommt der Beseitigung unzulaessiger Betriebszustaende eine besondere Bedeutung zu. Im Gegensatz zum Normalbetrieb eines Netzes, wo Eingriffe in das Betriebsgeschehen durch den Schaltingenieur in der zentralen Netzleitstelle mit dem Ziel einer wirtschaftlich optimalen Fahrweise des Netzes erfolgen, die zudem in der Regel im voraus planbar und ohne Zeitdruck durchzufuehren sind, besteht nach Eintreten unzulaessiger Betriebszustaende Handlungsbedarf fuer schnelle Korrekturmassnahmen, um eine weitere Verschlechterung der Netzsicherheit wegen der Gefahr moeglicher Folgeereignisse, etwa verursacht durch das Ausloesen von Schutzeinrichtungen, zu verhindern. Trotz zunehmender Ausstattung der zentralen Netzleitstellen mit leistungsfaehigen Prozessrechnern mangelt es noch an schnellen rechnergestuetzten

  20. Optimum hot water temperature for absorption solar cooling

    Energy Technology Data Exchange (ETDEWEB)

    Lecuona, A.; Ventas, R.; Venegas, M.; Salgado, R. [Dpto. Ingenieria Termica y de Fluidos, Universidad Carlos III de Madrid, Avda. Universidad 30, 28911 Leganes, Madrid (Spain); Zacarias, A. [ESIME UPA, IPN, Av. de las Granjas 682, Col. Santa Catarina, 02550, D.F. Mexico (Mexico)

    2009-10-15

    The hot water temperature that maximizes the overall instantaneous efficiency of a solar cooling facility is determined. A modified characteristic equation model is used and applied to single-effect lithium bromide-water absorption chillers. This model is based on the characteristic temperature difference and serves to empirically calculate the performance of real chillers. This paper provides an explicit equation for the optimum temperature of vapor generation, in terms of only the external temperatures of the chiller. The additional data required are the four performance parameters of the chiller and essentially a modified stagnation temperature from the detailed model of the thermal collector operation. This paper presents and discusses the results for small capacity machines for air conditioning of homes and small buildings. The discussion highlights the influence of the relevant parameters. (author)

  1. Modelling the Cost Performance of a Given Logistics Network Operating Under Regular and Irregular Conditions

    NARCIS (Netherlands)

    Janic, M.

    2009-01-01

    This paper develops an analytical model for the assessment of the cost performance of a given logistics network operating under regular and irregular (disruptive) conditions. In addition, the paper aims to carry out a sensitivity analysis of this cost with respect to changes of the most influencing

  2. [Working conditions and professional risk for operational personnel of energy facilities].

    Science.gov (United States)

    Amirov, N Kh; Ilyukhin, N E; Rusin, M N; Krasnoshchekova, V N

    2013-01-01

    Features of working conditions and a state of health of operation personnel of the network companies of power industry were studied for the purpose of justification and introduction of preventive actions for the decrease in influence of factors of professional risk.

  3. Modelling the Cost Performance of a Given Logistics Network Operating Under Regular and Irregular Conditions

    NARCIS (Netherlands)

    Janic, M.

    2009-01-01

    This paper develops an analytical model for the assessment of the cost performance of a given logistics network operating under regular and irregular (disruptive) conditions. In addition, the paper aims to carry out a sensitivity analysis of this cost with respect to changes of the most influencing

  4. Does arousal interfere with operant conditioning of spike-wave discharges in genetic epileptic rats?

    NARCIS (Netherlands)

    Osterhagen, L.; Breteler, M.H.M.; Luijtelaar, E.L.J.M. van

    2010-01-01

    One of the ways in which brain computer interfaces can be used is neurofeedback (NF). Subjects use their brain activation to control an external device, and with this technique it is also possible to learn to control aspects of the brain activity by operant conditioning. Beneficial effects of NF

  5. Appetitive operant conditioning in mice: heritability and dissociability of training stages

    NARCIS (Netherlands)

    Malkki, H.A.I.; Donga, L.A.B.; de Groot, S.E.; Battaglia, F.P.; Brussaard, A.B.; Borst, J.G.G.; Elgersma, Y.; Galjart, N.; van der Horst, G.T.; Levelt, C.N.; Pennartz, C.M.A.; Smit, A.B.; Spruijt, B.M.; Verhage, M.; de Zeeuw, C.I.

    2010-01-01

    To study the heritability of different training stages of appetitive operant conditioning, we carried out behavioral screening of 5 standard inbred mouse strains, 28 recombinant-inbred (BxD) mouse lines and their progenitor strains C57BL/6J and DBA/2J. We also computed correlations between

  6. [Microbial air purity in hospitals. Operating theatres with air conditioning system].

    Science.gov (United States)

    Krogulski, Adam; Szczotko, Maciej

    2010-01-01

    The aim of this study was to show the influence of air conditioning control for microbial contamination of air inside the operating theatres equipped with correctly working air-conditioning system. This work was based on the results of bacteria and fungi concentration in hospital air obtained since 2001. Assays of microbial air purity conducted on atmospheric air in parallel with indoor air demonstrated that air filters applied in air-conditioning systems worked correctly in every case. To show the problem of fluctuation of bacteria concentration more precisely, every sequences of single results from successive measure series were examined independently.

  7. Predators in training: operant conditioning of novel behavior in wild Burmese pythons (Python molurus bivitattus).

    Science.gov (United States)

    Emer, Sherri A; Mora, Cordula V; Harvey, Mark T; Grace, Michael S

    2015-01-01

    Large pythons and boas comprise a group of animals whose anatomy and physiology are very different from traditional mammalian, avian and other reptilian models typically used in operant conditioning. In the current study, investigators used a modified shaping procedure involving successive approximations to train wild Burmese pythons (Python molurus bivitattus) to approach and depress an illuminated push button in order to gain access to a food reward. Results show that these large, wild snakes can be trained to accept extremely small food items, associate a stimulus with such rewards via operant conditioning and perform a contingent operant response to gain access to a food reward. The shaping procedure produced robust responses and provides a mechanism for investigating complex behavioral phenomena in massive snakes that are rarely studied in learning research.

  8. Molten Carbonate Fuel Cell performance analysis varying cathode operating conditions for carbon capture applications

    Science.gov (United States)

    Audasso, Emilio; Barelli, Linda; Bidini, Gianni; Bosio, Barbara; Discepoli, Gabriele

    2017-04-01

    The results of a systematic experimental campaign to verify the impact of real operating conditions on the performance of a complete Molten Carbonate Fuel Cell (MCFC) are presented. In particular, the effects of ageing and composition of water, oxygen and carbon dioxide in the cathodic feeding stream are studied through the analysis of current-voltage curves and Electrochemical Impedance Spectroscopy (EIS). Based on a proposed equivalent electrical circuit model and a fitting procedure, a correlation is found among specific operating parameters and single EIS coefficients. The obtained results suggest a new performance monitoring approach to be applied to MCFC for diagnostic purpose. Particular attention is devoted to operating conditions characteristic of MCFC application as CO2 concentrators, which, by feeding the cathode with exhaust gases, is a promising route for efficient and cheap carbon capture.

  9. Analysis of critical operating conditions for LV distribution networks with microgrids

    Science.gov (United States)

    Zehir, M. A.; Batman, A.; Sonmez, M. A.; Font, A.; Tsiamitros, D.; Stimoniaris, D.; Kollatou, T.; Bagriyanik, M.; Ozdemir, A.; Dialynas, E.

    2016-11-01

    Increase in the penetration of Distributed Generation (DG) in distribution networks, raises the risk of voltage limit violations while contributing to line losses. Especially in low voltage (LV) distribution networks (secondary distribution networks), impacts of active power flows on the bus voltages and on the network losses are more dominant. As network operators must meet regulatory limitations, they have to take into account the most critical operating conditions in their systems. In this study, it is aimed to present the impact of the worst operation cases of LV distribution networks comprising microgrids. Simulation studies are performed on a field data-based virtual test-bed. The simulations are repeated for several cases consisting different microgrid points of connection with different network loading and microgrid supply/demand conditions.

  10. Conceptualising the Impact of Arousal and Affective State on Training Outcomes of Operant Conditioning

    Directory of Open Access Journals (Sweden)

    Paul D. McGreevy

    2013-04-01

    Full Text Available Animal training relies heavily on an understanding of species-specific behaviour as it integrates with operant conditioning principles. Following on from recent studies showing that affective states and arousal levels may correlate with behavioural outcomes, we explore the contribution of both affective state and arousal in behavioural responses to operant conditioning. This paper provides a framework for assessing how affective state and arousal may influence the efficacy of operant training methods. It provides a series of three-dimensional conceptual graphs as exemplars to describing putative influences of both affective state and arousal on the likelihood of dogs and horses performing commonly desired behaviours. These graphs are referred to as response landscapes, and they highlight the flexibility available for improving training efficacy and the likely need for different approaches to suit animals in different affective states and at various levels of arousal. Knowledge gaps are discussed and suggestions made for bridging them.

  11. Effects of dynamic operating conditions on nitrification in biological rapid sand filters for drinking water treatment

    DEFF Research Database (Denmark)

    Lee, Carson Odell; Boe-Hansen, Rasmus; Musovic, Sanin

    2014-01-01

    Biological rapid sand filters are often used to remove ammonium from groundwater for drinking water supply. They often operate under dynamic substrate and hydraulic loading conditions, which can lead to increased levels of ammonium and nitrite in the effluent. To determine the maximum nitrification...... operating conditions. The ammonium removal rate of the filter was determined by the ammonium loading rate, but was independent of both the flow and influent ammonium concentration individually. Ammonia-oxidizing bacteria and archaea were almost equally abundant in the filter. Both ammonium removal...... rates and safe operating windows of rapid sand filters, a pilot scale rapid sand filter was used to test short-term increased ammonium loads, set by varying either influent ammonium concentrations or hydraulic loading rates. Ammonium and iron (flock) removal were consistent between the pilot...

  12. Choosing an optimum sand control method

    Directory of Open Access Journals (Sweden)

    Ehsan Khamehchi

    2015-06-01

    Full Text Available Formation sand control is always one of the main concerns of production engineers. There are some different methods to prevent sand production. Choosing a method for preventing formation sand production depends on different reservoir parameters and politic and economic conditions. Sometimes, economic and politic conditions are more effective to choose an optimum than reservoir parameters. Often, simultaneous investigation of politic and economic conditions with reservoir parameters has different results with what is expected. So, choosing the best sand control method is the result of thorough study. Global oil price, duration of sand control project and costs of necessary equipment for each method as economic and politic conditions and well productivity index as reservoir parameter are the main parameters studied in this paper.

  13. Performance evaluation of the DCMD desalination process under bench scale and large scale module operating conditions

    KAUST Repository

    Francis, Lijo

    2014-04-01

    The flux performance of different hydrophobic microporous flat sheet commercial membranes made of poly tetrafluoroethylene (PTFE) and poly propylene (PP) was tested for Red Sea water desalination using the direct contact membrane distillation (DCMD) process, under bench scale (high δT) and large scale module (low δT) operating conditions. Membranes were characterized for their surface morphology, water contact angle, thickness, porosity, pore size and pore size distribution. The DCMD process performance was optimized using a locally designed and fabricated module aiming to maximize the flux at different levels of operating parameters, mainly feed water and coolant inlet temperatures at different temperature differences across the membrane (δT). Water vapor flux of 88.8kg/m2h was obtained using a PTFE membrane at high δT (60°C). In addition, the flux performance was compared to the first generation of a new locally synthesized and fabricated membrane made of a different class of polymer under the same conditions. A total salt rejection of 99.99% and boron rejection of 99.41% were achieved under extreme operating conditions. On the other hand, a detailed water characterization revealed that low molecular weight non-ionic molecules (ppb level) were transported with the water vapor molecules through the membrane structure. The membrane which provided the highest flux was then tested under large scale module operating conditions. The average flux of the latter study (low δT) was found to be eight times lower than that of the bench scale (high δT) operating conditions.

  14. Optimum design of steel structures

    CERN Document Server

    Farkas, József

    2013-01-01

    This book helps designers and manufacturers to select and develop the most suitable and competitive steel structures, which are safe, fit for production and economic. An optimum design system is used to find the best characteristics of structural models, which guarantee the fulfilment of design and fabrication requirements and minimize the cost function. Realistic numerical models are used as main components of industrial steel structures. Chapter 1 containts some experiences with the optimum design of steel structures Chapter 2 treats some newer mathematical optimization methods. Chapter 3 gives formulae for fabrication times and costs. Chapters 4 deals with beams and columns. Summarizes the Eurocode rules for design. Chapter 5 deals with the design of tubular trusses. Chapter 6 gives the design of frame structures and fire-resistant design rules for a frame. In Chapters 7 some minimum cost design problems of stiffened and cellular plates and shells are worked out for cases of different stiffenings and loads...

  15. 3rd International Conference on Condition Monitoring of Machinery in Non-Stationary Operations

    CERN Document Server

    Rubini, Riccardo; D'Elia, Gianluca; Cocconcelli, Marco; Chaari, Fakher; Zimroz, Radoslaw; Bartelmus, Walter; Haddar, Mohamed

    2014-01-01

    This book presents the processings of the third edition of the Condition Monitoring of Machinery in Non-Stationary Operations (CMMNO13) which was held in Ferrara, Italy. This yearly event merges an international community of researchers who met – in 2011 in Wroclaw (Poland) and in 2012 in Hammamet (Tunisia) – to discuss issues of diagnostics of rotating machines operating in complex motion and/or load conditions. The growing interest of the industrial world on the topics covered by the CMMNO13 involves the fields of packaging, automotive, agricultural, mining, processing and wind machines in addition to that of the systems for data acquisition.The participation of speakers and visitors from industry makes the event an opportunity for immediate assessment of the potential applications of advanced methodologies for the signal analysis. Signals acquired from machines often contain contributions from several different components as well as noise. Therefore, the major challenge of condition monitoring is to po...

  16. Relationship between container ship underwater noise levels and ship design, operational and oceanographic conditions

    Science.gov (United States)

    McKenna, Megan F.; Wiggins, Sean M.; Hildebrand, John A.

    2013-05-01

    Low-frequency ocean ambient noise is dominated by noise from commercial ships, yet understanding how individual ships contribute deserves further investigation. This study develops and evaluates statistical models of container ship noise in relation to design characteristics, operational conditions, and oceanographic settings. Five-hundred ship passages and nineteen covariates were used to build generalized additive models. Opportunistic acoustic measurements of ships transiting offshore California were collected using seafloor acoustic recorders. A 5-10 dB range in broadband source level was found for ships depending on the transit conditions. For a ship recorded multiple times traveling at different speeds, cumulative noise was lowest at 8 knots, 65% reduction in operational speed. Models with highest predictive power, in order of selection, included ship speed, size, and time of year. Uncertainty in source depth and propagation affected model fit. These results provide insight on the conditions that produce higher levels of underwater noise from container ships.

  17. Optimum thickness of Mossbauer absorber

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    If recoilless fraction fa is available, the optimum absorber thickness dopt can be calculated by maximizing the signal to noise ratio or Q factor. In this work,an approach presented is to get experimental Qexp as a function of the thickness, and then fitting Qexp by its theoretical expression gives fa value. At last the dopt value is deduced from a maximum on the fitted curve. In such a way, thicknesses of six specimens with quadrupole or magnetic hyperfine splitting were optimized.

  18. Operating Modes Of Chemical Reactors Of Polymerization

    Directory of Open Access Journals (Sweden)

    Meruyert Berdieva

    2012-05-01

    Full Text Available In the work the issues of stable technological modes of operation of main devices of producing polysterol reactors have been researched as well as modes of stable operation of a chemical reactor have been presented, which enables to create optimum mode parameters of polymerization process, to prevent emergency situations of chemical reactor operation in industrial conditions.

  19. Droplets spectrum of air-assisted boom sprayers under different environmental and operational conditions

    Directory of Open Access Journals (Sweden)

    Robson S. Sasaki

    2016-01-01

    Full Text Available ABSTRACT During pesticide spraying, the psychrometric conditions of the air may cause evaporation of the droplets along their trajectory from the nozzle to the target. Thus, this study aimed to evaluate the effect of air psychrometric conditions and operating pressure on the droplet spectrum of air-assisted boom sprayers. The test was performed using a prototype equipped with an axial fan, a flow homogenizer, temperature and relative air humidity sensors, a spray nozzle and a gas-heating system to warm up the airflow. With the assembled system and the aid of a particle analyser, the JSF 11002 spray nozzle was evaluated with respect to droplet spectrum in four air psychrometric conditions (7, 14, 21 and 28 hPa and at four operating pressures (200, 300, 400 and 500 kPa. At the end, evaporation losses were observed during the sprayings. For a given operating pressure and for each increment of 1 hPa in vapor pressure deficit, there was a diameter reduction of approximately 0.0759, 0.518 and 1.514 μm for the parameters DV0.1, DV0.5 and DV0.9, respectively. The diameter of the droplets decreased as the operating pressure increased.

  20. Optimum blade loading for a powered rotor in descent

    Institute of Scientific and Technical Information of China (English)

    Ramin Modarres; David A. Peters

    2016-01-01

    The optimum loading for rotors has previously been found for hover, climb and wind turbine conditions;but, up to now, no one has determined the optimum rotor loading in descent. This could be an important design consideration for rotary-wing parachutes and low-speed des-cents. In this paper, the optimal loading for a powered rotor in descent is found from momentum theory based on a variational principle. This loading is compared with the optimal loading for a rotor in hover or climb and with the Betz rotor loading (which is optimum for a lightly-loaded rotor). Wake contraction for each of the various loadings is also presented.

  1. Structural characterization and condition for measurement statistics preservation of a unital quantum operation

    Science.gov (United States)

    Lee, Kai-Yan; Fung, Chi-Hang Fred; Chau, H. F.

    2013-05-01

    We investigate the necessary and sufficient condition for a convex cone of positive semidefinite operators to be fixed by a unital quantum operation ϕ acting on finite-dimensional quantum states. By reducing this problem to the problem of simultaneous diagonalization of the Kraus operators associated with ϕ, we can completely characterize the kinds of quantum states that are fixed by ϕ. Our work has several applications. It gives a simple proof of the structural characterization of a unital quantum operation that acts on finite-dimensional quantum states—a result not explicitly mentioned in earlier studies. It also provides a necessary and sufficient condition for determining what kind of measurement statistics is preserved by a unital quantum operation. Finally, our result clarifies and extends the work of Størmer by giving a proof of a reduction theorem on the unassisted and entanglement-assisted classical capacities, coherent information, and minimal output Renyi entropy of a unital channel acting on a finite-dimensional quantum state.

  2. On conditions for invertibility of difference and differential operators in weight spaces

    Energy Technology Data Exchange (ETDEWEB)

    Bichegkuev, Mairbek S [North-Ossetia State University, Vladikavkaz (Russian Federation)

    2011-08-31

    We obtain necessary and sufficient conditions for the invertibility of the difference operator D{sub E}:D(D{sub E}) subset of l{sup p}{sub {alpha}}{yields}l{sup p}{sub {alpha}}, (D{sub E} x)(n)=x(n+1)-Bx(n), n element of Z{sub +}, whose domain D(D{sub E}) is given by the condition x(0) element of E, where l{sup p}{sub {alpha}}=l{sup p}{sub {alpha}}(Z{sub +},X), p element of [1,{infinity}], is the Banach space of sequences (of vectors in a Banach space X) summable with weight {alpha}:Z{sub +}{yields}(0,{infinity}) for p element of [1,{infinity}) and bounded with respect to {alpha} for p={infinity}, B:X{yields}X is a bounded linear operator, and E is a closed B-invariant subspace of X. We give applications to the invertibility of differential operators with an unbounded operator coefficient (the generator of a strongly continuous operator semigroup) in weight spaces of functions.

  3. Reactivity variation's analysis in nuclear propulsion considering the operational real conditions requirements

    Energy Technology Data Exchange (ETDEWEB)

    Pires, Leonardo Paredes; Santos, Rubens Souza dos; Lapa, Marcelo Franklin, E-mail: leonardo_paredes@icloud.com, E-mail: lapa@ien.gov.br, E-mail: rsantos@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    The work presented in this paper highlights the need for the study to determine the reactivity variation ramps needed and possible to meet the real operational conditions required by a nuclear submarine in this several operating phases. In accordance with the operational needs and necessary maneuvers in certain tactical situations, large power variations in the propulsion are demanded. As these sudden and severe changes in propulsion come from the thermal power of nuclear origin, the operation of the nuclear island has to know what kind of answers and criticality variations are necessary to meet each demand speed required. It should be noted that these criticality inserts are conditioned, not only by the propulsion needs, but fundamentally by the imperative need to ensure the core integrity and the chain reaction sustainability considering the phenomenons and complex effects, nonlinear and retro-fed involved. It has to be determined what is the past and required time for each criticality insertion is perceived as motor power. Considering the highlighted aspects, this article concludes and indicates to its end, the need to establish a base operating transitional agenda, according to the naval combat doctrine, to be tested and analyzed under the aspects and peculiarities of kinetic reactors, with the purpose of being generated the appropriate criticality curves for each real need and their respective times of anticipated action. (author)

  4. Extended necessary condition for local operations and classical communication: Tight bound for all measurements

    Science.gov (United States)

    Cohen, Scott M.

    2015-06-01

    We give a necessary condition that a separable measurement can be implemented by local quantum operations and classical communication (LOCC) in any finite number of rounds of communication, generalizing and strengthening a result obtained previously. That earlier result involved a bound that is tight when the number of measurement operators defining the measurement is relatively small. The present results generalize that bound to one that is tight for any finite number of measurement operators, and we also provide an extension which holds when that number is infinite. We apply these results to the famous example on a 3 ×3 system known as "domino states," which were the first demonstration of nonlocality without entanglement. Our extended necessary condition provides another way of showing that these states cannot be perfectly distinguished by (finite-round) LOCC. It directly shows that this conclusion also holds for their related rotated domino states. We also introduce a class of problems involving the unambiguous discrimination of quantum states, each of which is an example where the states can be optimally discriminated by a separable measurement, but according to our condition, cannot be optimally discriminated by LOCC. These examples nicely illustrate the usefulness of the present results, since our earlier necessary condition, which the present result generalizes, is not strong enough to reach a conclusion in any of these cases.

  5. Online Condition Monitoring to Enable Extended Operation of Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Ryan M.; Bond, Leonard J.; Ramuhalli, Pradeep

    2012-03-31

    Safe, secure, and economic operation of nuclear power plants will remain of strategic significance. New and improved monitoring will likely have increased significance in the post-Fukushima world. Prior to Fukushima, many activities were already underway globally to facilitate operation of nuclear power plants beyond their initial licensing periods. Decisions to shut down a nuclear power plant are mostly driven by economic considerations. Online condition monitoring is a means to improve both the safety and economics of extending the operating lifetimes of nuclear power plants, enabling adoption of proactive aging management. With regard to active components (e.g., pumps, valves, motors, etc.), significant experience in other industries has been leveraged to build the science base to support adoption for online condition-based maintenance and proactive aging management in the nuclear industry. Many of the research needs are associated with enabling proactive management of aging in passive components (e.g., pipes, vessels, cables, containment structures, etc.). This paper provides an overview of online condition monitoring for the nuclear power industry with an emphasis on passive components. Following the overview, several technology/knowledge gaps are identified, which require addressing to facilitate widespread online condition monitoring of passive components.

  6. Large eddy simulation of cooling flows in underground subway station according to different PSD operating conditions

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Yong Jun; Kim, Jin Ho; Park, Sung Huk; Koo, Dong Hoe [Korea Railroad Research Institute, Uiwang (Korea, Republic of)

    2015-11-15

    Large eddy simulation (LES) method is applied to systematically investigate the cooling fluid flow and the temperature distribution under the operating of air conditioning in the deeply underground subway station. The Shin-Gum-Ho subway station in Seoul which is the 8{sup th} floor and 43.6 m deep is selected for this analysis. The entire station is covered for simulation. The ventilation mode for air conditioning is kept as ordinary state. Different operating conditions for Platform screen door (PSD) are applied. First one is PSD is completely close and second one is PSD is regularly open and close which imitate the actual circumstances in the platform. The ventilation diffusers are modeled as 95 square shapes in the lobby and 222 squares in the platform. The temperature variations and flow behaviors are numerically simulated after operating of air conditioning for the whole station and the calculated results are compared with experimental data. LES method solves the momentum and thermal equations. Werner-Wengle wall law is applied to viscous sub layers for near wall resolution. The total grid numbers are 7.5 million and the whole domain is divided to 22 blocks. Multi blocks are computed in parallel using MPI. The results show the temperature difference in the platform between PSD-close and PSD-regularly open and close cases is 3-4 .deg. C.

  7. Simulation Evaluation of Controller-Managed Spacing Tools under Realistic Operational Conditions

    Science.gov (United States)

    Callantine, Todd J.; Hunt, Sarah M.; Prevot, Thomas

    2014-01-01

    Controller-Managed Spacing (CMS) tools have been developed to aid air traffic controllers in managing high volumes of arriving aircraft according to a schedule while enabling them to fly efficient descent profiles. The CMS tools are undergoing refinement in preparation for field demonstration as part of NASA's Air Traffic Management (ATM) Technology Demonstration-1 (ATD-1). System-level ATD-1 simulations have been conducted to quantify expected efficiency and capacity gains under realistic operational conditions. This paper presents simulation results with a focus on CMS-tool human factors. The results suggest experienced controllers new to the tools find them acceptable and can use them effectively in ATD-1 operations.

  8. Numerical simulations of the first operational conditions of the negative ion test facility SPIDER

    Energy Technology Data Exchange (ETDEWEB)

    Serianni, G., E-mail: gianluigi.serianni@igi.cnr.it; Agostinetti, P.; Antoni, V.; Baltador, C.; Chitarin, G.; Marconato, N.; Pasqualotto, R.; Sartori, E.; Toigo, V.; Veltri, P. [Consorzio RFX (CNR, ENEA, INFN, UNIPD, Acciaierie Venete SpA), Corso Stati Uniti 4, 35127 Padova (Italy); Cavenago, M. [INFN-LNL, Viale dell’Università n. 2, 35020 Legnaro (Italy)

    2016-02-15

    In view of the realization of the negative ion beam injectors for ITER, a test facility, named SPIDER, is under construction in Padova (Italy) to study and optimize production and extraction of negative ions. The present paper is devoted to the analysis of the expected first operations of SPIDER in terms of single-beamlet and multiple-beamlet simulations of the hydrogen beam optics in various operational conditions. The effectiveness of the methods adopted to compensate for the magnetic deflection of the particles is also assessed. Indications for a sequence of the experimental activities are obtained.

  9. EFFECT OF OPERATION CONDITIONS ON CHANGE OF PUBLIC AND PRIVATE EFFICIENCY OF THE CAR

    Directory of Open Access Journals (Sweden)

    S. Krivoshapov

    2015-12-01

    Full Text Available The basic principles of analytical determination of the efficiency of the entire vehicle and individual units are stated. The dependences of change of the efficiency depending on the speed and load modes of vehicle operation are specified. The mathematical model takes into account the real characteristics of the road and transport machines operating conditions. The results of calculation of the indicator and the mechanical efficiency of the engine, transmission and the wheel efficiency, total efficiency of the car, depending on the category of roads, weight and the speed of the machine on example of GAZ-3307 truck are presented.

  10. Lipase production by solid-state fermentation: cultivation conditions and operation of tray and packed-bed bioreactors.

    Science.gov (United States)

    Gutarra, Melissa L E; Cavalcanti, Elisa D C; Castilho, Leda R; Freire, Denise M G; Sant'Anna, Geraldo L

    2005-01-01

    The production of lipase by Penicillium simplicissimum in solid-state fermentation was studied using babassu cake as the basal medium. Tray-type and packed-bed bioreactors were employed. In the former, the influence of temperature; content of the medium, and medium supplementation with olive oil, sugarcane molasses, corn steep liquor, and yeast hydrolysate was studied. For all combinations of supplements, a temperature of 30 degrees C, a moisture content of 70%, and a concentration of carbon source of 6.25% (m/m, dry basis) provided optimum conditions for lipase production. When used as single supplements olive oil and molasses also were able to provide high lipase activities (20 U/g). Using packed-bed bioreactors and molasses-supplemented medium, optimum conditions for enzyme production were air superficial velocities above 55 cm/min and temperatures below 28 degrees C. The lower temperature optimum found for these reactors is probably related to radial heat gradient formation inside the packed bed. Maximum lipase activities obtained in these bioreactors (26.4 U/g) were 30% higher than in tray-type reactors.

  11. Operational Reliability Assessment of Compressor Gearboxes with Normalized Lifting Wavelet Entropy from Condition Monitoring Information

    Directory of Open Access Journals (Sweden)

    Xiaoli Zhang

    2015-05-01

    Full Text Available Classical reliability assessment methods have predominantly focused on probability and statistical theories, which are insufficient in assessing the operational reliability of individual mechanical equipment with time-varying characteristics. A new approach to assess machinery operational reliability with normalized lifting wavelet entropy from condition monitoring information is proposed, which is different from classical reliability assessment methods depending on probability and statistics analysis. The machinery vibration signals with time-varying operational characteristics are firstly decomposed and reconstructed by means of a lifting wavelet package transform. The relative energy of every reconstructed signal is computed as an energy percentage of the reconstructed signal in the whole signal energy. Moreover, a normalized lifting wavelet entropy is defined by the relative energy to reveal the machinery operational uncertainty. Finally, operational reliability degree is defined by the quantitative value obtained by the normalized lifting wavelet entropy belonging to the range of [0, 1]. The proposed method is applied in the operational reliability assessment of the gearbox in an oxy-generator compressor to validate the effectiveness.

  12. Solutions from boundary condition changing operators in open string field theory

    CERN Document Server

    Kiermaier, Michael; Soler, Pablo

    2010-01-01

    We construct analytic solutions of open string field theory using boundary condition changing (bcc) operators. We focus on bcc operators with vanishing conformal weight such as those for regular marginal deformations of the background. For any Fock space state phi, the component string field of the solution Psi exhibits a remarkable factorization property: it is given by the matter three-point function of phi with a pair of bcc operators, multiplied by a universal function that only depends on the conformal weight of phi. This universal function is given by a simple integral expression that can be computed once and for all. The three-point functions with bcc operators are thus the only needed physical input of the particular open string background described by the solution. We illustrate our solution with the example of the rolling tachyon profile, for which we prove convergence analytically. The form of our solution, which involves bcc operators instead of explicit insertions of the marginal operator, can b...

  13. Selection of optimum blowers is higly important for energy conservation in ventilation and air conditioning engineering: High-performance radial blowers without a housing; Auswahl des optimalen Ventilators fuer Energieeinsparung in der Luft- und Klimatechnik von grosser Bedeutung: Hochleistungs-Radialventilatoren ohne Gehaeuse

    Energy Technology Data Exchange (ETDEWEB)

    Lexis, J. [Ingenieurbuero Beratung und Planung Luft- und Klimatechnik, Feucht bei Nuernberg (Germany)

    1998-12-01

    There isn`t another component in ventilation and air-conditioning whose choice can result in as much energy conservation as the choice of the optimum blower. Awareness of this fact is increasing. (orig.) [Deutsch] Mit keiner anderen Komponente in der Luft- und Klimatechnik kann so viel Energie gespart werden wie mit der Auswahl des optimalen Ventilators. Deshalb wird der Auswahl des Ventilators immer mehr Aufmerksamkeit geschenkt. (orig.)

  14. 遗传算法优化变工况板翅式换热器的通道排列%Optimum passage arrangement for multi-stream plate-fin heat exchanger in various conditions through genetic algorithm

    Institute of Scientific and Technical Information of China (English)

    胡云云; 肖武; 贺高红

    2012-01-01

    the design of plate-fin heat exchanger. In the traditional plate-fin heat exchanger design, the passage arrangement is usually designed at a single maximum load operation point, which ignores the impact of heat transfer when the operation point changes very much. But in fact the operation conditions change along with seasons, raw materials and production circumstances, which usually lows the plate-fin heat exchanger's heat transfer when it works at these operation points. The number of the passage arrangement increases exponentially with the increase of fluid number in the plate-fin heat exchanger, so the passage arrangement is determined according to the experiential rule, which needs designers spend a lot of time in repeatedly improving the heat exchanger's passage arrangement to comply with the design requirements, and achieve superior heat transfer effect. To overcome this shortcoming, a novel flexible design method was presented in the paper based on flexible design of passage arrangement for multi-stream plate-fin heat exchanger in various conditions. The objective function was the minimum mean-square deviation of accumulative heat load of the passage arrangement, and genetic algorithm (GA) was adopted to attain the optimal passage arrangement. Specific steps: 1) GA was used to achieve the best passage arrangement at every operation point; 2) Flexible design was used to combine the different best passage arrangements to get flexible design passage arrangement which can worked well at all operation points; 3) Fine-tuning strategy was used to improve flexible design channel arrangement to get the final optimal passage arrangement by reducing the mean-square deviation of accumulative heat load. Finally an illustrative example was presented to demonstrate the validity and advantages of the proposed approach, the final passage arrangement's average mean-square deviation of accumulative heat load of three different operation points was 3632.48 W, which was lower than

  15. Study of Solids and Gas Distribution in Spouted Bed Operated In Stable and Unstable Conditions

    Directory of Open Access Journals (Sweden)

    Alwan, G. M.,

    2014-02-01

    Full Text Available A spouted bed is a special case of fluidization. It is an effective means of contacting gas with coarse solid particles. Spouted beds should be designed and operated to overcome performance instability and improves the uniform distribution of particles. Steady-state measurements were carried out in the 0.152 m ID cylindrical spouted bed made of Plexiglas that used 60° conical shape spout-air bed. The evaluation of solid and gas holdup in the two regions of spouted bed at stable and an unstable condition was performed using optical probe. The comparison of the radial profiles at the two conditions showed that the variation was in the spout region. The annulus region had similar profiles in both the condition as it acts as a loose packed bed, moving slowly downward. Stable bed was obtained at low gas velocity of 0.74 m/s and instability of spouting was observed at high gas velocity of 1.4 m/s. The beads can fluidize homogenously at stable conditions, while pulsation of the bed was appeared at unstable spout. Different flow regimes and characteristics can be obtained with minor variations in geometry or operating conditions.

  16. Plow longwall operations under challenging geological conditions; Durchoerterung von Stoerungen mit Hobelstreben

    Energy Technology Data Exchange (ETDEWEB)

    Voss, Heinz-Werner [RAG Anthrazit Ibbenbueren GmbH, Ibbenbueren (Germany); Witthaus, Holger; Junker, Martin [RAG Mining Solutions GmbH, Herne (Germany)

    2012-11-01

    In German coal mining, comprehensive experience is available in the grading of geological faults. The available experience has produced a level of expertise which enables the maintenance of high production figures even under difficult conditions. This is demonstrated by the many successful projects of RAG. The paper describes in the following several successful case examples and illustrates that the collected know-how can be used globally, even for future challenges, by German RAG Mining Solutions GmbH to successfully operate modern high-performance plough companies under difficult conditions. (orig.)

  17. Operating conditions effect over the coupling strength for urban aerial ropeways

    Directory of Open Access Journals (Sweden)

    Ronald M. MARTINOD

    2014-09-01

    Full Text Available The present work is aimed to assess the operating conditions effect for urban aerial ropeways with a commercial usage, based on measurements obtained from an arrangement of sensors that record the coupling assembly behavior between the detachable gondola pod and the track rope. The work pays particular attention to the effect caused by external conditions due to the wind loads joined up with other parasite external effects, through the measurement of the engage strains. The cableway gondola continuous cycle has mono-cable of simple ring type.

  18. Response Load Extrapolation for Wind Turbines during Operation Based on Average Conditional Exceedance Rates

    DEFF Research Database (Denmark)

    Toft, Henrik Stensgaard; Naess, Arvid; Saha, Nilanjan;

    2011-01-01

    The paper explores a recently developed method for statistical response load (load effect) extrapolation for application to extreme response of wind turbines during operation. The extrapolation method is based on average conditional exceedance rates and is in the present implementation restricted......-of-plane bending moment and the tower mudline bending moment of a pitch-controlled wind turbine. In general, the results show that the method based on average conditional exceedance rates predicts the extrapolated characteristic response loads at the individual mean wind speeds well and results in more consistent...

  19. High-speed flow visualization in a pump-turbine under off-design operating conditions

    Energy Technology Data Exchange (ETDEWEB)

    Hasmatuchi, V; Roth, S; Botero, F; Avellan, F; Farhat, M, E-mail: vlad.hasmatuchi@epfl.c [Laboratory for Hydraulic Machines, Ecole Polytechnique Federale de Lausanne Av. de Cour 33bis, Lausanne, CH-1007 (Switzerland)

    2010-08-15

    The flow hydrodynamics in a low specific speed radial pump-turbine reduced scale model is experimentally investigated under off-design operating conditions in generating mode. Wall pressure measurements, in the stator, synchronized with high-speed flow visualizations in the vaneless space between the impeller and the guide vanes using air bubbles injection are performed. When starting from the best efficiency point and increasing the runner speed, a significant increase of the pressure fluctuations is observed mainly in channels between wicket gates. The spectral analysis shows a rise of one stall cell, rotating with about 70% of the impeller frequency, at runaway, which further increases as the zero discharge condition is approached. Then a specific image processing technique is detailed and applied to create a synthetic instantaneous view of the flow pattern on the entire guide vanes circumference for an operating point in turbine-brake mode, where backflow and vortices accompany the stall passage.

  20. Compliance with Operational Circular No. 2 on conditions of access to the fenced CERN sites

    CERN Multimedia

    Relations with the Host States Service

    2004-01-01

    The purpose of Operational Circular No. 2 is to contribute to the protection of people and property by defining the conditions of access to the Organization's fenced sites. However, recently, the services concerned have noted a significant increase in the instances of non-compliance with those conditions that cannot be tolerated, for example: use of CERN access cards by people, other than the cardholders themselves, in order to gain access to facilities without having attended the required safety course; speeding, particularly on Route Gregory and Route Weisskopf; driving in and out of the site on the wrong side of the road; parking on spaces set aside for the disabled; nuisance parking, especially in the proximity of the Restaurants; the dumping of wrecked vehicles. As the aforementioned instances of non-compliance can lead to dangerous situations, the Organization reserves the right to apply the penalties provided for under paragraph 26 of Operational Circular No. 2, namely to refuse access to the site...

  1. REMINDER - Compliance with Operational Circular No. 2 on conditions of access to the fenced CERN sites

    CERN Multimedia

    Relations with the Host States Service

    2004-01-01

    The purpose of Operational Circular No. 2 is to contribute to the protection of people and property by defining the conditions of access to the Organization's fenced sites. However, recently, the services concerned have noted a significant increase in the instances of non-compliance with those conditions that cannot be tolerated, for example: use of CERN access cards by people, other than the cardholders themselves, in order to gain access to facilities without having attended the required safety course; speeding, particularly on Route Gregory and Route Weisskopf; driving in and out of the site on the wrong side of the road; parking on spaces set aside for the disabled; nuisance parking, especially in the proximity of the Restaurants; the dumping of wrecked vehicles. As the aforementioned instances of non-compliance can lead to dangerous situations, the Organization reserves the right to apply the penalties provided for under paragraph 26 of Operational Circular No. 2, namely to refuse access to the site ...

  2. Operating wind turbines in strong wind conditions by using feedforward-feedback control

    Science.gov (United States)

    Feng, Ju; Sheng, Wen Zhong

    2014-12-01

    Due to the increasing penetration of wind energy into power systems, it becomes critical to reduce the impact of wind energy on the stability and reliability of the overall power system. In precedent works, Shen and his co-workers developed a re-designed operation schema to run wind turbines in strong wind conditions based on optimization method and standard PI feedback control, which can prevent the typical shutdowns of wind turbines when reaching the cut-out wind speed. In this paper, a new control strategy combing the standard PI feedback control with feedforward controls using the optimization results is investigated for the operation of variable-speed pitch-regulated wind turbines in strong wind conditions. It is shown that the developed control strategy is capable of smoothening the power output of wind turbine and avoiding its sudden showdown at high wind speeds without worsening the loads on rotor and blades.

  3. Operating wind turbines in strong wind conditions by using feedforward-feedback control

    DEFF Research Database (Denmark)

    Feng, Ju; Shen, Wen Zhong

    2014-01-01

    the optimization results is investigated for the operation of variable-speed pitch-regulated wind turbines in strong wind conditions. It is shown that the developed control strategy is capable of smoothening the power output of wind turbine and avoiding its sudden showdown at high wind speeds without worsening......Due to the increasing penetration of wind energy into power systems, it becomes critical to reduce the impact of wind energy on the stability and reliability of the overall power system. In precedent works, Shen and his co-workers developed a re-designed operation schema to run wind turbines...... in strong wind conditions based on optimization method and standard PI feedback control, which can prevent the typical shutdowns of wind turbines when reaching the cut-out wind speed. In this paper, a new control strategy combing the standard PI feedback control with feedforward controls using...

  4. Detection of Partial Demagnetization Fault in PMSMs Operating under Nonstationary Conditions

    DEFF Research Database (Denmark)

    Wang, Chao; Delgado Prieto, Miguel; Romeral, Luis

    2016-01-01

    Demagnetization fault detection of in-service Permanent Magnet Synchronous Machines (PMSMs) is a challenging task because most PMSMs operate under nonstationary circumstances in industrial applications. A novel approach based on tracking characteristic orders of stator current using Vold-Kalman F......Demagnetization fault detection of in-service Permanent Magnet Synchronous Machines (PMSMs) is a challenging task because most PMSMs operate under nonstationary circumstances in industrial applications. A novel approach based on tracking characteristic orders of stator current using Vold......-Kalman Filter is proposed to detect the partial demagnetization fault in PMSMs running at nonstationary conditions. Amplitude of envelope of the fault characteristic orders is used as fault indictor. Experimental results verify the superiority of the proposed method on partial demagnetization online fault...... detection of PMSMs under various speed and load conditions....

  5. Thermal-hydraulics of LLCB TBM under different ITER operational conditions

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhuri, Paritosh, E-mail: paritc@gmail.com; Ranjithkumar, S.; Sharma, Deepak; Danani, Chandan; Kumar, E. Rajendra

    2016-11-01

    Highlights: • Thermal analysis of LLCB TBM has been performed for different ITER operations during normal and power excursion scenarios. • It is observed that in all ITER operations, the temperatures in all components of LLCB TBM are well within the limits. • The maximum temperature of CB-1 in steady state is 920 °C, which is 72% of the maximum temperature obtained in ITER pulse. - Abstract: Lead–lithium cooled ceramic breeder (LLCB) TBM is the Indian DEMO relevant blanket module, which will be tested in one-half of a designated ITER port from day 1 operation of ITER. LLCB TBM will be tested in various ITER operational phases. Different TBM may be tested corresponding to the four different phases of plasma operation. The paper present a review of thermal analyses based on the various heat loads on the LLCB TBM obtained from neutronics calculations to confirm heat removal and structural integrity under different ITER operational conditions. This includes the normal plasma operation, fusion power excursions, surface heat flux due to MARFES, disruption heat loads during thermal and current quench etc., in inductive and non-inductive plasma operations. Transient events, like plasma disruption, vertical displacement events (VDEs) and edge localized modes (ELMs) deliver considerable heat flux (high power densities) for short durations onto the first wall of TBM. Detailed thermal-hydraulic simulation studies have been performed using ANSYS. These analyses, therefore, will provide important information about the temperature distribution in different materials used in TBM and their temperature-time histories.

  6. Method for Prediction of the Power Output from Photovoltaic Power Plant under Actual Operating Conditions

    Science.gov (United States)

    Obukhov, S. G.; Plotnikov, I. A.; Surzhikova, O. A.; Savkin, K. D.

    2017-04-01

    Solar photovoltaic technology is one of the most rapidly growing renewable sources of electricity that has practical application in various fields of human activity due to its high availability, huge potential and environmental compatibility. The original simulation model of the photovoltaic power plant has been developed to simulate and investigate the plant operating modes under actual operating conditions. The proposed model considers the impact of the external climatic factors on the solar panel energy characteristics that improves accuracy in the power output prediction. The data obtained through the photovoltaic power plant operation simulation enable a well-reasoned choice of the required capacity for storage devices and determination of the rational algorithms to control the energy complex.

  7. Waste to energy plant operation under the influence of market and legislation conditioned changes

    DEFF Research Database (Denmark)

    Tomic, Tihomir; Dominkovic, Dominik Franjo; Pfeifer, Antun

    2017-01-01

    In this paper, gate-fee changes of the waste-to-energy plants are investigated in the conditions set by European Union legislation and by the introduction of the new heat market. Waste management and sustainable energy supply are core issues of sustainable development of regions, especially urban...... areas. These two energy flows logically come together in the combined heat and power facility by waste incineration. However, the implementation of new legislation influences quantity and quality of municipal waste and operation of waste-to-energy systems. Once the legislation requirements are met......, waste-to-energy plants need to be adapted to market operation. This influence is tracked by the gate-fee volatility. The operation of the waste-to-energy plant on electricity markets is simulated by using EnergyPLAN and heat market is simulated in Matlab, based on hourly marginal costs. The results have...

  8. Control of hybrid AC/DC microgrid under islanding operational conditions

    DEFF Research Database (Denmark)

    Ding, G.; Gao, F.; Zhang, S.

    2014-01-01

    This paper presents control methods for hybrid AC/DC microgrid under islanding operation condition. The control schemes for AC sub-microgrid and DC sub-microgrid are investigated according to the power sharing requirement and operational reliability. In addition, the key control schemes...... of interlinking converter with DC-link capacitor or energy storage, which will devote to the proper power sharing between AC and DC sub-microgrids to maintain AC and DC side voltage stable, is reviewed. Combining the specific control methods developed for AC and DC sub-microgrids with interlinking converter......, the whole hybrid AC/DC microgrid can manage the power flow transferred between sub-microgrids for improving on the operational quality and efficiency....

  9. Microstructure degradation of LSM-YSZ cathode in SOFCs operated at various conditions

    DEFF Research Database (Denmark)

    Liu, Yi-Lin; Thydén, Karl Tor Sune; Chen, Ming

    2012-01-01

    mechanisms have been identified. And it has been observed that different mechanisms dominate the degradation process under different test conditions. The severe cathode degradation at 750 °C operation with high current density is attributed to a loss of the cathode/electrolyte interface stability......Systematic microstructural analyses have been carried out on a series of technological SOFCs that went through long-term cell tests with various operating parameters including temperature, current load and time length under current. For the LSM-YSZ cathode, a number of microstructure degradation....... For the cells tested at 850 °C, the interface stability is maintained due to further sintering during cell operation. A cell test lasting for 2 years (17500 h) at 850 °C with a moderate current density (not greater than 1 A/cm2) has shown that the cathode microstructure is fairly robust to the degradation...

  10. Mechanical Properties of a Unidirectional Basalt-Fiber-Reinforced Plastic Under a Loading Simulating Operation Conditions

    Science.gov (United States)

    Lobanov, D. S.; Slovikov, S. V.

    2017-01-01

    The results of experimental investigations of unidirectional composites based on basalt fibers and different marks of epoxy resins are presented. Uniaxial tensile tests were carried out using a specimen fixation technique simulating the operation conditions of structures. The mechanical properties of the basalt-fiber-reinforced plastics (BFRPs) were determined. The diagrams of loading and deformation of BFRP specimens were obtain. The formulations of the composites with the highest mechanical properties were revealed.

  11. Temperature limits for LMFBR fuel cladding under upset and emergency operating conditions

    Energy Technology Data Exchange (ETDEWEB)

    Govindarajan, S.; Chetal, S.C. [Indira Gandhi Centre for Atomic Research, Kalpakkam Tamilnadu (India). Nuclear Systems Division

    1996-07-01

    LMFBR fuel pin cladding tube is subjected to high transient temperatures during incidents such as pump trip, pump to grid plate pipe rupture etc. It is required to know temperature limits under such transient operating conditions for components involved while analyzing such incidents. A methodology for deriving such limits for fuel clad tube is worked out in this paper by making use of the transient damage correlation proposed by W.F. Brizes et. al.

  12. Mathematical Model of Bridge-Linked Photovoltaic Arrays Operating Under Irregular Conditions

    OpenAIRE

    Juan D. Bastidas-Rodríguez; Carlos A. Ramos-Paja; Luz A. Trejos-Grisales

    2013-01-01

    This paper presents a mathematical procedure to model a photovoltaic array (N rows and M columns) in bridge-linked configuration operating under regular and irregular conditions. The proposed procedure uses the ideal single-diode model representation for each photovoltaic module and the Shockley equation to represent each bypass diode. To pose the system of NxM non-linear equations required to obtain the voltages of each module of the array, the proposed model apply the Kirchhoff current law ...

  13. EFFECTS OF OPERATING CONDITIONS ON THE DEPOSITION OF GaAs IN A VERTICAL CVD REACTOR

    OpenAIRE

    JAE-SANG BAEK; JIN-HYO BOO; YOUN-JEA KIM

    2008-01-01

    A numerical study is needed to gain insight into the growth mechanism and improve the reactor design or optimize the deposition condition in chemical vapor deposition (CVD). In this study, we have performed a numerical analysis of the deposition of gallium arsenide (GaAs) from trimethyl gallium (TMG) and arsine in a vertical CVD reactor. The effects of operating parameters, such as the rotation velocity of susceptor, inlet velocity, and inlet TMG fraction, are investigated and presented. The ...

  14. Differential gene expression in the rat hippocampus during learning of an operant conditioning task.

    Science.gov (United States)

    Rapanelli, M; Frick, L R; Zanutto, B S

    2009-11-10

    Changes in transcription levels of brain-derived neurotrophic factor (BDNF), cyclic adenosine monophosphate (cAMP) response element binding (CREB), Synapsin I, Ca(2+)/calmodulin-dependent protein kinase II (CamKII), activity-regulated cytoskeleton-associated protein (Arc), c-jun and c-fos have been associated to several learning paradigms in different brain areas. In this study, we measured mRNA expression in the hippocampus by real time (RT)-PCR mRNA levels of BDNF, CREB, Synapsin I, CamKII, Arc, c-jun and c-fos, during learning and operant conditioning task. Experimental groups were as follows: control (C, the animals never left the bioterium), when the animals reached 50-65% of the expected response (Incompletely Trained, IT), when animals reached 100% of the expected response with a latency time lower than 5 s (Trained, Tr), Box Control of Incompletely Trained (BCIT), animals spent the same time as the IT in the operant conditioning box and Box Control of Trained (BCTr) animals spent the same time as the Tr in the operant conditioning box. All rats were killed at the same time by cervical dislocation 15 min after training and hippocampi were removed and processed. We found increments of mRNA levels of most genes (BDNF, CREB, Synapsin I, Arc, c-jun and c-fos) in IT and Tr groups compared to their box controls, but increments in Tr were smaller compared with IT. These results describe a differential gene expression in the rat hippocampus when the animals are learning and when animals have already learned. Taking together the results presented herein with the known functions of these genes, we propose a link between changes in gene expression in the hippocampus and different degrees of cellular activation and plasticity during learning of an operant conditioning task.

  15. Influence of Met-Ocean Condition Forecasting Uncertainties on Weather Window Predictions for Offshore Operations

    DEFF Research Database (Denmark)

    Gintautas, Tomas; Sørensen, John Dalsgaard

    2017-01-01

    The article briefly presents a novel methodology of weather window estimation for offshore operations and mainly focuses on effects of met-ocean condition forecasting uncertainties on weather window predictions when using the proposed methodology. It is demonstrated that the proposed methodology...... to include stochastic variables, representing met-ocean forecasting uncertainties and the results of such modification are given in terms of predicted weather windows for a selected test case....

  16. Multifunctional ultrasonic sensor for on-line tool condition monitoring in turning operations

    Energy Technology Data Exchange (ETDEWEB)

    Nayfeh, T.H.; Abu-Zahra, N.H. [Cleveland State Univ., OH (United States). Industrial Engineering Dept.

    1998-03-01

    Machining operations in automated manufacturing centers are, in general, under-performing by 20--80 percent. Optimizing these machining operations requires on-line knowledge of the cutting tool`s condition and the process state. Currently, this information is either not reliable or not available in a timely manner. This in part is due to the lack of suitable sensors which are able to measure on-line directly and accurately one or more of the relevant tool and process variables. A direct, active, ultrasonic method for on-line sensing of the tool condition and the process state in turning operations was developed in this work. Sensing is achieved by using an ultrasonic transducer operating at 10 MHz in a pulse-echo mode to send pulses through the cutting tool. The amplitude and propagation time of the reflected pulses are modulated by the tool nose, flank, temperature, and by the material in contact with the tools. This method has the potential to measure on-line several relevant process and cutting tool parameters directly and accurately through the use of a single sensor. These parameters are tool-workpiece contact, tool gradual wear, tool chipping and tool chatter.

  17. Operation reliability assessment for cutting tools by applying a proportional covariate model to condition monitoring information.

    Science.gov (United States)

    Cai, Gaigai; Chen, Xuefeng; Li, Bing; Chen, Baojia; He, Zhengjia

    2012-09-25

    The reliability of cutting tools is critical to machining precision and production efficiency. The conventional statistic-based reliability assessment method aims at providing a general and overall estimation of reliability for a large population of identical units under given and fixed conditions. However, it has limited effectiveness in depicting the operational characteristics of a cutting tool. To overcome this limitation, this paper proposes an approach to assess the operation reliability of cutting tools. A proportional covariate model is introduced to construct the relationship between operation reliability and condition monitoring information. The wavelet packet transform and an improved distance evaluation technique are used to extract sensitive features from vibration signals, and a covariate function is constructed based on the proportional covariate model. Ultimately, the failure rate function of the cutting tool being assessed is calculated using the baseline covariate function obtained from a small sample of historical data. Experimental results and a comparative study show that the proposed method is effective for assessing the operation reliability of cutting tools.

  18. Impacts of operating conditions and solution chemistry on osmotic membrane structure and performance

    KAUST Repository

    Wong, Mavis C.Y.

    2012-02-01

    Herein, we report on changes in the performance of a commercial cellulose triacetate (CTA) membrane, imparted by varied operating conditions and solution chemistries. Changes to feed and draw solution flow rate did not significantly alter the CTA membrane\\'s water permeability, salt permeability, or membrane structural parameter when operated with the membrane skin layer facing the draw solution (PRO-mode). However, water and salt permeability increased with increasing feed or draw solution temperature, while the membrane structural parameter decreased with increasing draw solution, possibly due to changes in polymer intermolecular interactions. High ionic strength draw solutions may de-swell the CTA membrane via charge neutralization, which resulted in lower water permeability, higher salt permeability, and lower structural parameter. This observed trend was further exacerbated by the presence of divalent cations which tends to swell the polymer to a greater extent. Finally, the calculated CTA membrane\\'s structural parameter was lower and less sensitive to external factors when operated in PRO-mode, but highly sensitive to the same factors when the skin layer faced the feed solution (FO-mode), presumably due to swelling/de-swelling of the saturated porous substructure by the draw solution. This is a first attempt aimed at systematically evaluating the changes in performance of the CTA membrane due to operating conditions and solution chemistry, shedding new insight into the possible advantages and disadvantages of this material in certain applications. © 2011 Elsevier B.V.

  19. Soleus H-Reflex Operant Conditioning Changes The H-Reflex Recruitment Curve

    Science.gov (United States)

    Thompson, Aiko K.; Chen, Xiang Yang; Wolpaw, Jonathan R.

    2012-01-01

    Introduction Operant conditioning can gradually change the human soleus H-reflex. The protocol conditions the reflex near M-wave threshold. This study examined its impact on the reflexes at other stimulus strengths. Methods H-reflex recruitment curves were obtained before and after a 24-session exposure to an up-conditioning (HRup) or down-conditioning (HRdown) protocol and were compared. Results In both HRup and HRdown subjects, conditioning affected the entire H-reflex recruitment curve. In 5 of 6 HRup and 3 of 6 HRdown subjects, conditioning elevated (HRup) or depressed (HRdown), respectively, the entire curve. In the other HRup subject or the other 3 HRdown subjects, the curve was shifted to the left or to the right, respectively. Discussion H-reflex conditioning does not simply change the H-reflex to a stimulus of particular strength; it also changes the H-reflexes to stimuli of different strengths. Thus, it is likely to affect many actions in which this pathway participates. PMID:23281107

  20. Experimental fuel cell performance analysis under different operating conditions and bipolar plate designs

    Energy Technology Data Exchange (ETDEWEB)

    Iranzo, Alfredo; Pino, Javier; Rosa, Felipe [Energy Engineering Department, School of Engineering, University of Seville, Camino de los Descubrimientos s/n, 41092 Seville (Spain); Munoz, Miguel; Lopez, Eduardo [INTA - National Institute for Aerospace Technology, Ctra. San Juan del Puerto-Matalascanas km 33, 21130 Mazagon (Huelva) (Spain)

    2010-10-15

    This work presents experimental performance results for a 50 cm{sup 2} Polymer Electrolyte Membrane (PEM) Fuel Cell, including polarization curves and Electrochemical Impedance Spectroscopy (EIS) analysis of the Fuel Cell. EIS results were used for the determination of the cell ohmic resistance as well as charge transfer resistances under different operating conditions. Different combinations of operating conditions and bipolar plate designs were analysed. In particular, the effect of the cathode oxygen concentration, reactant gases humidification, and bipolar plate (BP) design were assessed. Butler-Volmer (BV) kinetic parameters such as the charge transfer coefficient were also determined from Tafel plots. The electronic contact resistances were measured for both Bipolar Plate designs, and the membrane protonic resistances were calculated. Its dependence on the BP flow field design and operating conditions is addressed. The results obtained in this work are aimed both at gaining insight into the fundamental processes determining the fuel cell performance, and at determining parameters needed for Computational Fuel Cell Dynamics (CFCD) numerical simulations. (author)

  1. An operant conditioning method for studying auditory behaviors in marmoset monkeys.

    Directory of Open Access Journals (Sweden)

    Evan D Remington

    Full Text Available The common marmoset (Callithrix jacchus is a small New World primate that has increasingly been used as a non-human model in the fields of sensory, motor, and cognitive neuroscience. However, little knowledge exists regarding behavioral methods in this species. Developing an understanding of the neural basis of perception and cognition in an animal model requires measurement of both brain activity and behavior. Here we describe an operant conditioning behavioral training method developed to allow controlled psychoacoustic measurements in marmosets. We demonstrate that marmosets can be trained to consistently perform a Go/No-Go auditory task in which a subject licks at a feeding tube when it detects a sound. Correct responses result in delivery of a food reward. Crucially, this operant conditioning task generates little body movement and is well suited for pairing behavior with single-unit electrophysiology. Successful implementation of an operant conditioning behavior opens the door to a wide range of new studies in the field of auditory neuroscience using the marmoset as a model system.

  2. Associations of emotional arousal, dissociation and symptom severity with operant conditioning in borderline personality disorder.

    Science.gov (United States)

    Paret, Christian; Hoesterey, Steffen; Kleindienst, Nikolaus; Schmahl, Christian

    2016-10-30

    Those with borderline personality disorder (BPD) display altered evaluations regarding reward and punishment compared to others. The processing of rewards is basal for operant conditioning. However, studies addressing operant conditioning in BPD patients are rare. In the current study, an operant conditioning task combining learning acquisition and reversal was used. BPD patients and matched healthy controls (HCs) were exposed to aversive and neutral stimuli to assess the influence of emotion on learning. Picture content, dissociation, aversive tension and symptom severity were rated. Error rates were measured. Results showed no group interactions between aversive versus neutral scenes. The higher emotional arousal, dissociation and tension, the worse the acquisition, but not reversal, scores were for BPD patients. Scores from the Borderline Symptom List were associated with more errors in the reversal, but not the acquisition phase. The results are preliminary evidence for impaired acquisition learning due to increased emotional arousal, dissociation and tension in BPD patients. A failure to process punishment in the reversal phase was associated with symptom severity and may be related to neuropsychological dysfunctioning involving the ventromedial prefrontal cortex. Conclusions are limited due to the correlational study design and the small sample size. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  3. Erosion corrosion of CuCrZr specimens exposed for simulated ITER operational conditions

    Directory of Open Access Journals (Sweden)

    C. Obitz

    2016-12-01

    The erosion corrosion and release rates of CuCrZr and CuCrZr/316L(N-IG joints were derived from weight change data and metallographic examinations of specimens after autoclave exposures at 110°C, 150°C and 250°C at reducing-, oxidizing- and cyclic redox water chemistry conditions. Reducing water chemistry represents periods considered as the nominal off-plasma operational conditions while the oxidizing environment simulates situations when the plasma is active. The cyclic redox conditions represent periods with shorter cycles simulating plasma activations with subsequent periodical variation of the water chemistry from reducing to oxidizing. The erosion corrosion rates for CuCrZr at active plasma conditions were 20 and 40µm/year at 110 and 150°C. At 250°C the corresponding rate was much higher. This result gives important information on what may happen if, for example, a First Wall panel is exposed to an unexpectedly high heat flux. Under reducing conditions the erosion corrosion rates were 3µm/year and 20µm/year at 110°C and 250°C respectively. The results at 250°C under off-plasma conditions reveal that the effect of erosion corrosion also has to be taken into account during baking. Cyclic conditions with respect to oxidant content turned out to be the most demanding environment (more demanding than pure oxidizing conditions for the CuCrZr-alloy. Erosion corrosion rates of 90µm/year and 370µm/year at 110 and 150°C were recorded respectively. The highest temperature 250°C was not tested. This raise the question whether measures should be introduced that renders the system either oxidizing or reducing. In summary, the erosion corrosion rates recorded for CuCrZr under simulated ITER coolant water conditions are high, especially during plasma operation. For comparison it can be mentioned that corrosion rates of structural materials in the primary loop of light water reactors generally are considerably lower than 1µm/year. The estimated rates for Cu

  4. Atlas Based Kinematic Optimum Design of the Stewart Parallel Manipulator

    Institute of Scientific and Technical Information of China (English)

    SHAO Zhufeng; TANG Xiaoqiang; WANG Liping; SUN Dengfeng

    2015-01-01

    Optimum design is a key approach to make full use of potential advantages of a parallel manipulator. The optimum design of multi-parameter parallel manipulators(more than three design parameters), such as Stewart manipulator, relies on analysis based and algorithm based optimum design methods, which fall to be accurate or intuitive. To solve this problem and achieve both accurate and intuition, atlas based optimum design of a general Stewart parallel manipulator is established, with rational selection of design parameters. Based on the defined spherical usable workspace(SUW), primary kinematic performance indices of the Stewart manipulator, involving workspace and condition number are introduced and analyzed. Then, corresponding performance atlases are drawn with the established non-dimensional design space, and impact of joint distribution angles on the manipulator performance is analyzed and illustrated. At last, an example on atlas based optimum design of the Stewart manipulator is accomplished to illustrate the optimum design process, considering the end-effector posture. Deduced atlases can be flexibly applied to both quantitative and qualitative analysis to get the desired optimal design for the Stewart manipulator with respect to related performance requirements. Besides, the established optimum design method can be further applied to other multi-parameter parallel manipulators.

  5. 75 FR 70090 - Special Conditions: Bombardier Inc. Model CL-600-2E25 Airplane, Operation Without Normal...

    Science.gov (United States)

    2010-11-17

    ... Airplane, Operation Without Normal Electrical Power AGENCY: Federal Aviation Administration (FAA), DOT... without normal electrical power,'' requires safe operation in VFR conditions for at least five minutes with inoperative normal electrical power. The applicable airworthiness regulations do not...

  6. Investigation of Tribological Behaviour of GF Filled Peek Composite under the Harsh Operating Conditions

    Directory of Open Access Journals (Sweden)

    Shelke Vijay R

    2015-11-01

    Full Text Available Composite materials have successfully substituted the traditional materials in several light weight and high strength applications. The reasons why composites are selected for such applications are mainly their high strength-to-weight ratio, high tensile strength at elevated temperatures, high creep resistance and high toughness. Therefore minimum Wear of component or part used in machinery is very important factor for the industry. In this paper the tribological behavior of PEEK (Poly-ether-ether-ketone composites reinforced by 30% short glass fiber and phosphor bronze were comparatively evaluated on Pin on disc machine. The effect of three parameters such as temperature, load and sliding distance on Wear loss of PEEK composites reinforced by 30% short glass fiber and phosphor bronze were examined. The detailed mathematical model is simulated by Minitab 17 and simulation results fit experiment data very well In this investigation, an effective approach based on Taguchi method, analysis of variance (ANOVA, multivariable linear regression (MVLR, has been developed to determine the optimum conditions leading to minimum Wear. Experiments were conducted by varying temperature, load and sliding distance using L9 orthogonal array of Taguchi method. The present work aims at optimizing process parameters to achieve minimum Wear. Experimental results from the orthogonal array were used as the training data for the MVLR model to map the relationship between process parameters and Wear. The experiment was conducted on computerized Pin on Disc machine. It was observed that PEEK 30% Glass Fiber Composite Polymer has excellent wear resistance compare to Phosphor bronze at elevated temperature.

  7. Restoring Walking after SCI: Operant Conditioning of Spinal Reflexes Can Help

    Science.gov (United States)

    Thompson, Aiko K.; Wolpaw, Jonathan R.

    2014-01-01

    People with incomplete spinal cord injury (SCI) frequently suffer motor disabilities due to spasticity and poor muscle control, even after conventional therapy. Abnormal spinal reflex activity often contributes to these problems. Operant conditioning of spinal reflexes, which can target plasticity to specific reflex pathways, can enhance recovery. In rats in which a right lateral column lesion had weakened right stance and produced an asymmetrical gait, up-conditioning of the right soleus H-reflex, which increased muscle spindle afferent excitation of soleus, strengthened right stance and eliminated the asymmetry. In people with hyperreflexia due to incomplete SCI, down-conditioning of the soleus H-reflex improved walking speed and symmetry. Furthermore, modulation of EMG activity during walking improved bilaterally, indicating that a protocol that targets plasticity to a specific pathway can trigger widespread plasticity that improves recovery far beyond that attributable to the change in the targeted pathway. These improvements were apparent to people in their daily lives. They reported walking faster and farther, and noted less spasticity and better balance. Operant conditioning protocols could be developed to modify other spinal reflexes or corticospinal connections; and could be combined with other therapies to enhance recovery in people with SCI or other neuromuscular disorders. PMID:24636954

  8. The improving of the heat networks operating process under the conditions of the energy efficiency providing

    Directory of Open Access Journals (Sweden)

    Blinova Tatiana

    2016-01-01

    Full Text Available Among the priorities it is important to highlight the modernization and improvement of energy efficiency of housing and communal services, as well as the transition to the principle of using the most efficient technologies used in reproduction (construction, creation of objects of municipal infrastructure and housing modernization. The main hypothesis of this study lies in the fact that in modern conditions the realization of the most important priorities of the state policy in the sphere of housing and communal services, is possible in the conditions of use of the most effective control technologies for the reproduction of thermal networks. It is possible to raise the level of information security Heat Distribution Company, and other market participants by improving business processes through the development of organizational and economic mechanism in the conditions of complex monitoring of heat network operation processes

  9. Air-conditioning vs. presence of pathogenic fungi in hospital operating theatre environment.

    Science.gov (United States)

    Gniadek, Agnieszka; Macura, Anna B

    2011-01-01

    Infections related to modern surgical procedures present a difficult problem for contemporary medicine. Infections acquired during surgery represent a risk factor related to therapeutical interventions. Eradication of microorganisms from hospital operating theatre environment may contribute to reduction of infections as the laminar flow air-conditioning considerably reduces the number of microorganisms in the hospital environment. The objective of the study was to evaluate the occurrence of fungi in air-conditioned operating theatre rooms. The study was carried out in one of the hospitals in Krak6w during December 2009. Indoor air samples and imprints from the walls were collected from five operating theatre rooms. A total of fifty indoor air samples were collected with a MAS-100 device, and twenty five imprints from the walls were collected using a Count Tact method. Fungal growth was observed in 48 air samples; the average numbers of fungi were within the range of 5-100 c.f.u. in one cubic metre of the air. Fungi were detected only in four samples of the wall imprints; the number of fungi was 0.01 c.f.u. per one square centimetre of the surface. The mould genus Aspergillus was most frequently isolated, and the species A. fumigatus and A. versicolor were the dominating ones. To ensure microbiological cleanness of hospital operating theatre, the air-conditioning system should be properly maintained. Domination of the Aspergillus fungi in indoor air as well as increase in the number of moulds in the samples taken in evenings (p < 0.05) may suggest that the room decontamination procedures were neglected.

  10. Thermal Comfort and Optimum Humidity Part 1

    Directory of Open Access Journals (Sweden)

    M. V. Jokl

    2002-01-01

    Full Text Available The hydrothermal microclimate is the main component in indoor comfort. The optimum hydrothermal level can be ensured by suitable changes in the sources of heat and water vapor within the building, changes in the environment (the interior of the building and in the people exposed to the conditions inside the building. A change in the heat source and the source of water vapor involves improving the heat - insulating properties and the air permeability of the peripheral walls and especially of the windows. The change in the environment will bring human bodies into balance with the environment. This can be expressed in terms of an optimum or at least an acceptable globe temperature, an adequate proportion of radiant heat within the total amount of heat from the environment (defined by the difference between air and wall temperature, uniform cooling of the human body by the environment, defined a by the acceptable temperature difference between head and ankles, b by acceptable temperature variations during a shift (location unchanged, or during movement from one location to another without a change of clothing. Finally, a moisture balance between man and the environment is necessary (defined by acceptable relative air humidity. A change for human beings means a change of clothes which, of course, is limited by social acceptance in summer and by inconvenient heaviness in winter. The principles of optimum heating and cooling, humidification and dehumidification are presented in this paper.Hydrothermal comfort in an environment depends on heat and humidity flows (heat and water vapors, occurring in a given space in a building interior and affecting the total state of the human organism.

  11. Thermal Comfort and Optimum Humidity Part 2

    Directory of Open Access Journals (Sweden)

    M. V. Jokl

    2002-01-01

    Full Text Available The hydrothermal microclimate is the main component in indoor comfort. The optimum hydrothermal level can be ensured by suitable changes in the sources of heat and water vapor within the building, changes in the environment (the interior of the building and in the people exposed to the conditions inside the building. A change in the heat source and the source of water vapor involves improving the heat - insulating properties and the air permeability of the peripheral walls and especially of the windows. The change in the environment will bring human bodies into balance with the environment. This can be expressed in terms of an optimum or at least an acceptable globe temperature, an adequate proportion of radiant heat within the total amount of heat from the environment (defined by the difference between air and wall temperature, uniform cooling of the human body by the environment, defined a by the acceptable temperature difference between head and ankles, b by acceptable temperature variations during a shift (location unchanged, or during movement from one location to another without a change of clothing. Finally, a moisture balance between man and the environment is necessary (defined by acceptable relative air humidity. A change for human beings means a change of clothes which, of course, is limited by social acceptance in summer and by inconvenient heaviness in winter. The principles of optimum heating and cooling, humidification and dehumidification are presented in this paper.Hydrothermal comfort in an environment depends on heat and humidity flows (heat and water vapors, occurring in a given space in a building interior and affecting the total state of the human organism.

  12. Operant Conditioning in Honey Bees (Apis mellifera L.): The Cap Pushing Response

    Science.gov (United States)

    Abramson, Charles I.; Dinges, Christopher W.; Wells, Harrington

    2016-01-01

    The honey bee has been an important model organism for studying learning and memory. More recently, the honey bee has become a valuable model to understand perception and cognition. However, the techniques used to explore psychological phenomena in honey bees have been limited to only a few primary methodologies such as the proboscis extension reflex, sting extension reflex, and free flying target discrimination-tasks. Methods to explore operant conditioning in bees and other invertebrates are not as varied as with vertebrates. This may be due to the availability of a suitable response requirement. In this manuscript we offer a new method to explore operant conditioning in honey bees: the cap pushing response (CPR). We used the CPR to test for difference in learning curves between novel auto-shaping and more traditional explicit-shaping. The CPR protocol requires bees to exhibit a novel behavior by pushing a cap to uncover a food source. Using the CPR protocol we tested the effects of both explicit-shaping and auto-shaping techniques on operant conditioning. The goodness of fit and lack of fit of these data to the Rescorla-Wagner learning-curve model, widely used in classical conditioning studies, was tested. The model fit well to both control and explicit-shaping results, but only for a limited number of trials. Learning ceased rather than continuing to asymptotically approach the physiological most accurate possible. Rate of learning differed between shaped and control bee treatments. Learning rate was about 3 times faster for shaped bees, but for all measures of proficiency control and shaped bees reached the same level. Auto-shaped bees showed one-trial learning rather than the asymptotic approach to a maximal efficiency. However, in terms of return-time, the auto-shaped bees’ learning did not carry over to the covered-well test treatments. PMID:27626797

  13. Operant Conditioning in Honey Bees (Apis mellifera L.): The Cap Pushing Response.

    Science.gov (United States)

    Abramson, Charles I; Dinges, Christopher W; Wells, Harrington

    2016-01-01

    The honey bee has been an important model organism for studying learning and memory. More recently, the honey bee has become a valuable model to understand perception and cognition. However, the techniques used to explore psychological phenomena in honey bees have been limited to only a few primary methodologies such as the proboscis extension reflex, sting extension reflex, and free flying target discrimination-tasks. Methods to explore operant conditioning in bees and other invertebrates are not as varied as with vertebrates. This may be due to the availability of a suitable response requirement. In this manuscript we offer a new method to explore operant conditioning in honey bees: the cap pushing response (CPR). We used the CPR to test for difference in learning curves between novel auto-shaping and more traditional explicit-shaping. The CPR protocol requires bees to exhibit a novel behavior by pushing a cap to uncover a food source. Using the CPR protocol we tested the effects of both explicit-shaping and auto-shaping techniques on operant conditioning. The goodness of fit and lack of fit of these data to the Rescorla-Wagner learning-curve model, widely used in classical conditioning studies, was tested. The model fit well to both control and explicit-shaping results, but only for a limited number of trials. Learning ceased rather than continuing to asymptotically approach the physiological most accurate possible. Rate of learning differed between shaped and control bee treatments. Learning rate was about 3 times faster for shaped bees, but for all measures of proficiency control and shaped bees reached the same level. Auto-shaped bees showed one-trial learning rather than the asymptotic approach to a maximal efficiency. However, in terms of return-time, the auto-shaped bees' learning did not carry over to the covered-well test treatments.

  14. Application-Ready Expedited MODIS Data for Operational Land Surface Monitoring of Vegetation Condition

    Directory of Open Access Journals (Sweden)

    Jesslyn F. Brown

    2015-12-01

    Full Text Available Monitoring systems benefit from high temporal frequency image data collected from the Moderate Resolution Imaging Spectroradiometer (MODIS system. Because of near-daily global coverage, MODIS data are beneficial to applications that require timely information about vegetation condition related to drought, flooding, or fire danger. Rapid satellite data streams in operational applications have clear benefits for monitoring vegetation, especially when information can be delivered as fast as changing surface conditions. An “expedited” processing system called “eMODIS” operated by the U.S. Geological Survey provides rapid MODIS surface reflectance data to operational applications in less than 24 h offering tailored, consistently-processed information products that complement standard MODIS products. We assessed eMODIS quality and consistency by comparing to standard MODIS data. Only land data with known high quality were analyzed in a central U.S. study area. When compared to standard MODIS (MOD/MYD09Q1, the eMODIS Normalized Difference Vegetation Index (NDVI maintained a strong, significant relationship to standard MODIS NDVI, whether from morning (Terra or afternoon (Aqua orbits. The Aqua eMODIS data were more prone to noise than the Terra data, likely due to differences in the internal cloud mask used in MOD/MYD09Q1 or compositing rules. Post-processing temporal smoothing decreased noise in eMODIS data.

  15. Experimental investigations on a common centrifugal pump operating under gas entrainment conditions

    Energy Technology Data Exchange (ETDEWEB)

    Schäfer, Thomas, E-mail: thomas.schaefer@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Fluid Dynamics (Germany); Neumann, Martin [Technische Universität Dresden, AREVA Endowed Chair of Imaging Techniques in Energy and Process Engineering (Germany); Bieberle, André [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Fluid Dynamics (Germany); Hampel, Uwe [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Fluid Dynamics (Germany); Technische Universität Dresden, AREVA Endowed Chair of Imaging Techniques in Energy and Process Engineering (Germany)

    2017-05-15

    Highlights: • The pump performance has been evaluated for several gas entrainment conditions. • The gas entraining flow regime has a large impact on the pump performance. • High-resolution gamma-ray computed tomography (HireCT) has been applied. • Gas holdup inside the operating impeller has been visualized and quantified. • Gas holdup profiles along selected streamlines have been calculated. - Abstract: This paper presents an experimental study on the effects of additional gas entrainment in centrifugal pumps designed for conveying liquid phases only. The pump performance has been evaluated for several gas entrainment conditions, and for various operational settings of the pump, such as its alignment and the rotational speed of the impeller. As a main performance indicator the impact of entrained gas on the hydraulic power of the pump has been analyzed using experimental data. Additionally, high-resolution gamma-ray computed tomography (HireCT) operated in time-averaged rotation-synchronized scanning mode has been applied to quantify local phase fraction distributions inside the rapidly rotating pump impeller. Based on these quantitative tomographic measurements, gas holdup profiles along selected streamlines have been calculated and gas accumulation areas inside the impeller chambers have been visualized. Thus, various internally accumulated gas holdup patterns have been identified and, eventually, associated with characteristic pump performance behaviors. Moreover, the tomographic measuring method allowed an enhanced gas holdup analysis in specified pump compartments. As a result, the related specific gas and liquid phase holdup profiles have been evaluated.

  16. Transient pressure measurements at part load operating condition of a high head model Francis turbine

    Indian Academy of Sciences (India)

    RAHUL GOYAL; CHIRAG TRIVEDI; B K GANDHI; MICHEL J CERVANTES; OLE G DAHLHAUG

    2016-11-01

    Hydraulic turbines are operating at part load conditions depending on availability of hydraulic energy or to meet the grid requirements. The turbine experiences more fatigue during the part load operating conditions due to flow phenomena such as vortex breakdown in the draft tube and flow instability in the runner.The present paper focuses on the investigation of a high head model Francis turbine operating at 50% load.Pressure measurements have been carried out experimentally on a model Francis turbine. Total six pressure sensors were mounted inside the turbine and other two pressure sensors were mounted at the turbine inlet pipe. It is observed that the turbine experiences significant pressure fluctuations at the vaneless space and the runner.Moreover, a standing wave is observed between the pressure tank outlet and the turbine inlet. Analysis of the data acquired by the pressure sensors mounted in the draft tube showed the presence of vortex breakdown corotating with the runner. The detailed analysis showed the rotating and plunging components of the vortex breakdown. The influence of the rotating component was observed in the entire hydraulic circuit includingdistributor and turbine inlet but not the plunging one.

  17. Numerical analysis of an entire ceramic kiln under actual operating conditions for the energy efficiency improvement.

    Science.gov (United States)

    Milani, Massimo; Montorsi, Luca; Stefani, Matteo; Saponelli, Roberto; Lizzano, Maurizio

    2017-04-05

    The paper focuses on the analysis of an industrial ceramic kiln in order to improve the energy efficiency and thus the fuel consumption and the corresponding carbon dioxide emissions. A lumped and distributed parameter model of the entire system is constructed to simulate the performance of the kiln under actual operating conditions. The model is able to predict accurately the temperature distribution along the different modules of the kiln and the operation of the many natural gas burners employed to provide the required thermal power. Furthermore, the temperature of the tiles is also simulated so that the quality of the final product can be addressed by the modelling. Numerical results are validated against experimental measurements carried out on a real ceramic kiln during regular production operations. The developed numerical model demonstrates to be an efficient tool for the investigation of different design solutions for the kiln's components. In addition, a number of control strategies for the system working conditions can be simulated and compared in order to define the best trade off in terms of fuel consumption and product quality. In particular, the paper analyzes the effect of a new burner type characterized by internal heat recovery capability aimed at improving the energy efficiency of the ceramic kiln. The fuel saving and the relating reduction of carbon dioxide emissions resulted in the order of 10% when compared to the standard burner. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Operational control of radiation conditions in Space Monitoring Data Center of Moscow State University

    Science.gov (United States)

    Kalegaev, Vladimir; Shugay, Yulia; Bobrovnikov, Sergey; Kuznetsov, Nikolay; Barinova, Vera; Myagkova, Irina; Panasyuk, Mikhail

    2016-07-01

    Space Monitoring Data Center (SMDC) of Moscow State University provides mission support for Russian satellites and give operational analysis of radiation conditions in space. SMDC Web-sites (http://smdc.sinp.msu.ru/ and http://swx.sinp.msu.ru/) give access to current data on the level of solar activity, geomagnetic and radiation state of Earth's magnetosphere and heliosphere in near-real time. For data analysis the models of space environment factors working online have been implemented. Interactive services allow one to retrieve and analyze data at a given time moment. Forecasting applications including solar wind parameters, geomagnetic and radiation condition forecasts have been developed. Radiation dose and SEE rate control are of particular importance in practical satellite operation. Satellites are always under the influence of high-energy particle fluxes during their orbital flight. The three main sources of particle fluxes: the Earth's radiation belts, the galactic cosmic rays, and the solar energetic particles (SEP), are taken into account by SMDC operational services to estimate the radiation dose caused by high-energy particles to a satellite at LEO orbits. ISO 15039 and AP8/AE8 physical models are used to estimate effects of galactic cosmic rays and radiation belt particle fluxes. Data of geosynchronous satellites (GOES or Electro-L1) allow to reconstruct the SEP fluxes spectra at a given low Earth orbit taking into account the geomagnetic cut-off depending on geomagnetic activity level.

  19. Tuning the heat transfer medium and operating conditions in magnetic refrigeration

    Science.gov (United States)

    Ghahremani, Mohammadreza; Aslani, Amir; Siddique, Abid; Bennett, Lawrence H.; Della Torre, Edward

    2016-07-01

    A new experimental test bed has been designed, built, and tested to evaluate the effect of the system's parameters on a reciprocating Active Magnetic Regenerator (AMR) near room temperature. Bulk gadolinium was used as the refrigerant, silicon oil as the heat transfer medium, and a magnetic field of 1.3 T was cycled. This study focuses on the methodology of single stage AMR operation conditions to get a high temperature span near room temperature. Herein, the main objective is not to report the absolute maximum attainable temperature span seen in an AMR system, but rather to find the system's optimal operating conditions to reach that maximum span. The results of this research show that there is a optimal operating frequency, heat transfer fluid flow rate, flow duration, and displaced volume ratio in any AMR system. By optimizing these parameters in our AMR apparatus the temperature span between the hot and cold ends increased by 24%. The optimized values are system dependent and need to be determined and measured for any AMR system by following the procedures that are introduced in this research. It is expected that such optimization will permit the design of a more efficient magnetic refrigeration system.

  20. Mathematical model of a plate fin heat exchanger operating under solid oxide fuel cell working conditions

    Science.gov (United States)

    Kaniowski, Robert; Poniewski, Mieczysław

    2013-12-01

    Heat exchangers of different types find application in power systems based on solid oxide fuel cells (SOFC). Compact plate fin heat exchangers are typically found to perfectly fit systems with power output under 5 kWel. Micro-combined heat and power (micro-CHP) units with solid oxide fuel cells can exhibit high electrical and overall efficiencies, exceeding 85%, respectively. These values can be achieved only when high thermal integration of a system is assured. Selection and sizing of heat exchangers play a crucial role and should be done with caution. Moreover, performance of heat exchangers under variable operating conditions can strongly influence efficiency of the complete system. For that reason, it becomes important to develop high fidelity mathematical models allowing evaluation of heat exchangers under modified operating conditions, in high temperature regimes. Prediction of pressure and temperatures drops at the exit of cold and hot sides are important for system-level studies. Paper presents dedicated mathematical model used for evaluation of a plate fin heat exchanger, operating as a part of micro-CHP unit with solid oxide fuel cells.

  1. Analytical solutions for determining extreme water levels in surge tank of hydropower station under combined operating conditions

    Science.gov (United States)

    Wang, Bingbao; Guo, Wencheng; Yang, Jiandong

    2017-06-01

    Combined operating condition usually refers to the control operating condition under which the highest and lowest water levels occur in a surge tank of hydropower station. In this paper, with the basic equations of surge analysis and nonlinear vibrational asymptotic method, analytical expressions of the worst superimposition time of surge waves in an upstream surge tank under four typical combined operating conditions (i.e. load-acceptance-then-rejection, successive load rejection, successive load acceptance and load-rejection-then-acceptance) are derived firstly. Then using these expressions, the analytical extreme water levels are determined. The analytical solutions are verified with numerical simulation results. Finally, the effect of the hydraulic resistance coefficient of surge tank on the control operating condition is investigated. The results indicate that: The analytical solutions for determining extreme water levels in surge tank under various combined operating conditions are accurate due to the good agreements between the analytical results and the numerical results. With the increase of the hydraulic resistance coefficient of surge tank, the control operating condition for the highest water level shifts from load-acceptance-then-rejection condition to successive load rejection condition, and the control operating condition for the lowest water level shifts from load-rejection-then-acceptance condition to successive load acceptance condition.

  2. Assessment of biogas production from MBT waste under different operating conditions

    Energy Technology Data Exchange (ETDEWEB)

    Pantini, Sara, E-mail: pantini@ing.uniroma2.it [Department of Civil Engineering and Computer Science Engineering, University of Rome “Tor Vergata”, Via del Politecnico, 1, 00133 Rome (Italy); Verginelli, Iason; Lombardi, Francesco [Department of Civil Engineering and Computer Science Engineering, University of Rome “Tor Vergata”, Via del Politecnico, 1, 00133 Rome (Italy); Scheutz, Charlotte; Kjeldsen, Peter [Department of Environmental Engineering, Technical University of Denmark, Miljoevej, Building 113, DK-2800 Kgs. Lyngby (Denmark)

    2015-09-15

    Highlights: • BMP test displayed high gas potential generation capacity of MBT waste. • Strong inhibition effects were observed due to ammonia and VFA accumulation. • Waste water content was found as the key parameter limiting gas generation. • First order k-values were determined for different operating conditions. - Abstract: In this work, the influence of different operating conditions on the biogas production from mechanically–biologically treated (MBT) wastes is investigated. Specifically, different lab-scale anaerobic tests varying the water content (26–43% w/w up to 75% w/w), the temperature (from 20 to 25 °C up to 55 °C) and the amount of inoculum have been performed on waste samples collected from a full-scale Italian MBT plant. For each test, the gas generation yield and, where applicable, the first-order gas generation rates were determined. Nearly all tests were characterised by a quite long lag-phase. This result was mainly ascribed to the inhibition effects resulting from the high concentrations of volatile fatty acids (VFAs) and ammonia detected in the different stages of the experiments. Furthermore, water content was found as one of the key factor limiting the anaerobic biological process. Indeed, the experimental results showed that when the moisture was lower than 32% w/w, the methanogenic microbial activity was completely inhibited. For the higher water content tested (75% w/w), high values of accumulated gas volume (up to 150 Nl/kgTS) and a relatively short time period to deplete the MBT waste gas generation capacity were observed. At these test conditions, the effect of temperature became evident, leading to gas generation rates of 0.007 d{sup −1} at room temperature that increased to 0.03–0.05 d{sup −1} at 37 °C and to 0.04–0.11 d{sup −1} at 55 °C. Overall, the obtained results highlighted that the operative conditions can drastically affect the gas production from MBT wastes. This suggests that particular caution

  3. Fully Electrical Modeling of Thermoelectric Generators with Contact Thermal Resistance Under Different Operating Conditions

    Science.gov (United States)

    Siouane, Saima; Jovanović, Slaviša; Poure, Philippe

    2017-01-01

    The Seebeck effect is used in thermoelectric generators (TEGs) to supply electronic circuits by converting the waste thermal into electrical energy. This generated electrical power is directly proportional to the temperature difference between the TEG module's hot and cold sides. Depending on the applications, TEGs can be used either under constant temperature gradient between heat reservoirs or constant heat flow conditions. Moreover, the generated electrical power of a TEG depends not only on these operating conditions, but also on the contact thermal resistance. The influence of the contact thermal resistance on the generated electrical power have already been extensively reported in the literature. However, as reported in Park et al. (Energy Convers Manag 86:233, 2014) and Montecucco and Knox (IEEE Trans Power Electron 30:828, 2015), while designing TEG-powered circuit and systems, a TEG module is mostly modeled with a Thévenin equivalent circuit whose resistance is constant and voltage proportional to the temperature gradient applied to the TEG's terminals. This widely used simplified electrical TEG model is inaccurate and not suitable under constant heat flow conditions or when the contact thermal resistance is considered. Moreover, it does not provide realistic behaviour corresponding to the physical phenomena taking place in a TEG. Therefore, from the circuit designer's point of view, faithful and fully electrical TEG models under different operating conditions are needed. Such models are mainly necessary to design and evaluate the power conditioning electronic stages and the maximum power point tracking algorithms of a TEG power supply. In this study, these fully electrical models with the contact thermal resistance taken into account are presented and the analytical expressions of the Thévenin equivalent circuit parameters are provided.

  4. Fully Electrical Modeling of Thermoelectric Generators with Contact Thermal Resistance Under Different Operating Conditions

    Science.gov (United States)

    Siouane, Saima; Jovanović, Slaviša; Poure, Philippe

    2016-09-01

    The Seebeck effect is used in thermoelectric generators (TEGs) to supply electronic circuits by converting the waste thermal into electrical energy. This generated electrical power is directly proportional to the temperature difference between the TEG module's hot and cold sides. Depending on the applications, TEGs can be used either under constant temperature gradient between heat reservoirs or constant heat flow conditions. Moreover, the generated electrical power of a TEG depends not only on these operating conditions, but also on the contact thermal resistance. The influence of the contact thermal resistance on the generated electrical power have already been extensively reported in the literature. However, as reported in Park et al. (Energy Convers Manag 86:233, 2014) and Montecucco and Knox (IEEE Trans Power Electron 30:828, 2015), while designing TEG-powered circuit and systems, a TEG module is mostly modeled with a Thévenin equivalent circuit whose resistance is constant and voltage proportional to the temperature gradient applied to the TEG's terminals. This widely used simplified electrical TEG model is inaccurate and not suitable under constant heat flow conditions or when the contact thermal resistance is considered. Moreover, it does not provide realistic behaviour corresponding to the physical phenomena taking place in a TEG. Therefore, from the circuit designer's point of view, faithful and fully electrical TEG models under different operating conditions are needed. Such models are mainly necessary to design and evaluate the power conditioning electronic stages and the maximum power point tracking algorithms of a TEG power supply. In this study, these fully electrical models with the contact thermal resistance taken into account are presented and the analytical expressions of the Thévenin equivalent circuit parameters are provided.

  5. Tip clearance noise of axial flow fans operating at design and off-design condition

    Science.gov (United States)

    Fukano, T.; Jang, C.-M.

    2004-08-01

    The noise due to tip clearance (TC) flow in axial flow fans operating at a design and off-design conditions is analyzed by an experimental measurement using two hot-wire probes rotating with the fan blades. The unsteady nature of the spectra of the real-time velocities measured by two hot-wire sensors in a vortical flow region is investigated by using cross-correlation coefficient and retarded time of the two fluctuating velocities. The results show that the noise due to TC flow consists of a discrete frequency noise due to periodic velocity fluctuation and a broadband noise due to velocity fluctuation in the blade passage. The peak frequencies in a vortical flow are mainly observed below at four harmonic blade passing frequency. The discrete frequency component of velocity fluctuation at the off-design operating conditions is generated in vortical flow region as well as in reverse flow region. The peak frequency can be an important noise source when the fans are rotated with a high rotational speed. The authors propose a spiral pattern of velocity fluctuation in the vortical flow to describe the generation mechanism of the peak frequency in the vortical flow. In addition, noise increase due to TC flow at low flow rate condition is analyzed with relation to the distribution of velocity fluctuation due to the interference between the tip leakage vortex and the adjacent pressure surface of the blade.

  6. Performance analysis of monary and binary geothermal power plants operation for Ukraine conditions

    Directory of Open Access Journals (Sweden)

    Аlla Е. Denysova

    2015-03-01

    Full Text Available Every day the shortage in natural gas and coal does increase. In this respect, a great attention is paid to alternative energy sources, and geothermal electrical power generation represents one of the most cost-effective technologies. New power generation technologies using geothermal resources are ecologically clean and are close approaching to traditional ones from the efficiency point of view. This research aim is to analyze the efficiency of monary and binary geothermal power plants operation under actual conditions in Ukraine. Authors discuss prospects for the geothermal power engineering development in Ukraine and other countries. The principal thermal diagrams of monary and binary power plants are represented, as well as their operational principle considering these schemes advantages and disadvantages. Effected is an analysis of such stations performances under conditions of Ukraine. This research value and practical significance are related to the fact that for Ukraine both monary and binary geothermal power plants are very promising, but each engineering solutions should strictly follow its specific functional conditions.

  7. REGARDING "TRAGIC ECONOMIC OPTIMUM" FROM HOLISTIC+ PERSPECTIVE

    Directory of Open Access Journals (Sweden)

    Constantin Popescu

    2010-12-01

    Full Text Available Communication aims to discuss the new scientific vision of "the entire integrated" as it follows the recent achievements of quantum physics, psychology and biology. From this perspective, economy is seen as a living organism, part of the social organism and together with de bright ecology. The optimum of the economy as a living organism is based on dynamic compatibilities with all common living requirements. The evolution of economic life is organically linked to the unavoidable circumstances contained in the form of V. Frankl ‘s tragic triad consisting of: pain, guilt and death. In interaction with the holistic triad circumscribed by limitations, uncertainties and open interdependencies, the tragic economic optimum (TEO is formed. It can be understood as that state of economic life in which freedom of choice of scarce resources under uncertainty has in the compatibility of rationality and hope the development criteria of MEANING. TEO means to say YES to economic life even in conditions of resource limitations, bankruptcies and unemployment, negative externalities, stress, etc. By respiritualization of responsibility using scientific knowledge. TEO - involves multicriteria modeling of economic life by integrating human demands, community, environmental, spiritual and business development in the assessment predicting human GDP as a variable wave aggregate.

  8. Enhanced Operation of Electricity Distribution Grids Through Smart Metering PLC Network Monitoring, Analysis and Grid Conditioning

    Directory of Open Access Journals (Sweden)

    Iker Urrutia

    2013-01-01

    Full Text Available Low Voltage (LV electricity distribution grid operations can be improved through a combination of new smart metering systems’ capabilities based on real time Power Line Communications (PLC and LV grid topology mapping. This paper presents two novel contributions. The first one is a new methodology developed for smart metering PLC network monitoring and analysis. It can be used to obtain relevant information from the grid, thus adding value to existing smart metering deployments and facilitating utility operational activities. A second contribution describes grid conditioning used to obtain LV feeder and phase identification of all connected smart electric meters. Real time availability of such information may help utilities with grid planning, fault location and a more accurate point of supply management.

  9. Operational conditions for successful partial nitrification in a sequencing batch reactor (SBR) based on process kinetics.

    Science.gov (United States)

    Liu, Xiaoguang; Kim, Mingu; Nakhla, George

    2017-03-01

    The objective of this study is to analyze the factors affecting the performance of partial nitrification in a sequencing batch reactor (SBR) using kinetic models. During the 4-month operation, dissolved oxygen (DO) and influent ammonia concentration were selected as operating variables to evaluate nitrite accumulation. Stable partial nitrification was observed with two conditions, influent ammonia concentration of 190 mg N/L and a DO of 0.6-3.0 mg/L as well as influent ammonia concentration of 100 mg N/L and a DO of 0.15-2.0 mg/L with intermittent aeration. At a DO of 0.6-3.0 mg O2/L and influent ammonia concentration of 90 mg N/L, nitrite-oxidizing bacteria growth was not suppressed. Kinetic parameters were determined or estimated with batch tests and model simulation. The kinetic model predicted the SBR performance well.

  10. Equiconvergence of spectral decompositions of 1D Dirac operators with regular boundary conditions

    CERN Document Server

    Djakov, Plamen

    2011-01-01

    One dimensional Dirac operators $$ L_{bc}(v) y = i 1 & 0 0 & -1 \\frac{dy}{dx} + v(x) y, \\quad y = y_1 y_2, \\quad x\\in[0,\\pi]$$, considered with $L^2$-potentials $ v(x) = 0 & P(x) Q(x) & 0$ and subject to regular boundary conditions ($bc$), have discrete spectrum. For strictly regular $bc,$ the spectrum of the free operator $ L_{bc}(0) $ is simple while the spectrum of $ L_{bc}(v) $ is eventually simple, and the corresponding normalized root function systems are Riesz bases. For expansions of functions of bounded variation about these Riesz bases, we prove the uniform equiconvergence property and point-wise convergence on the closed interval $[0,\\pi].$ Analogous results are obtained for regular but not strictly regular $bc.$

  11. High-Density Fiber Optical Sensor and Instrumentation for Gas Turbine Operation Condition Monitoring

    Directory of Open Access Journals (Sweden)

    Hua Xia

    2013-01-01

    Full Text Available Gas turbine operation control is normally based on thermocouple-measured exhaust temperatures. Due to radiation shielding and bulky package, it is difficult to provide high spatial resolution for measuring can-to-can combustion temperature profile at the exhaust duct. This paper has demonstrated that wavelength-division-multiplexing-based fiber Bragg grating sensors could provide high spatial resolution steady and dynamic temperature measurements. A robust sensor package can be designed with either circumferential sensing cable or radial sensing rake for quasi-distributing multiple fiber sensors in the gas turbine environment. The field validations have demonstrated that quasi-distributed fiber sensors have not only demonstrated its temperature measurement accuracy compared to existing thermocouple sensors but also shown its unique dynamic response amplitude and power spectra that could be utilized for gas turbine transient operation condition monitoring and diagnostics.

  12. LHC Beam Dump Design Study - Part III : Off-normal operating conditions

    CERN Document Server

    Bruno, L; Ross, M; Sala, P

    2000-01-01

    The LHC beam dump design study has been preliminarily substantiated by energy deposition simulations (Part I) and heat transfer analyses (Part II). The present report is devoted to the abnormal operating conditions induced by a malfunction of the beam diluters. A general approach to the analysis of off-normal operation is presented, which is derived from standard design norms adopted in the nuclear industry. Attention is focused mainly on the carbon core, which is longitudinally split into segments of different density in order to better distribute the deposited energy. The maximum energy density it absorbs decreases by at least 33%, compared to a uniform standard density carbon core. This structure may sustain any partial sweep failure without major damage, up to the ultimate beam intensity and energy. To minimise the risks inherent in a fully unswept beam, a sacrificial graphite mandrel will be placed on the core axis, surrounded by a thick high strength carbon-carbon composite tube. With this arrangement, ...

  13. The 4-D descent trajectory generation techniques under realistic operating conditions

    Science.gov (United States)

    Williams, David H.; Knox, Charles E.

    1990-01-01

    NASA-Langley has been conducting and sponsoring research in airborne energy management for a number of years. During the course of this research, two fundamental techniques for the generation of 4D (fixed time) descent trajectories have emerged as viable candidates for advanced flight management systems. The first technique utilizes speed schedules of constant Mach number transitioning to constant calibrated airspeed chosen empirically to produce minimum fuel usage. The second technique computes cost optimized speed schedules of variable airspeed developed through application of optimal control theory. Both techniques have been found to produce reasonable and flyable descent trajectories. The formulation of the algorithms for each technique is evaluated and their suitability for operations in realistic conditions is discussed. Operational factors considered include: airplace speed, thrust, and altitude rate constaints; wind, temperature, and pressure variations; Air Traffic Control altitude, speed, and time constaints; and pilot interface and guidance considerations. Time flexibility, fuel usage, and airborne computational requirements were the primary performance measures.

  14. Final Report - Advanced MEA's for Enhanced Operating Conditions, Amenable to High Volume Manufacture

    Energy Technology Data Exchange (ETDEWEB)

    Debe, Mark K.

    2007-09-30

    This report summarizes the work completed under a 3M/DOE contract directed at advancing the key fuel cell (FC) components most critical for overcoming the polymer electrolyte membrane fuel cell (PEMFC) performance, durability & cost barriers. This contract focused on the development of advanced ion exchange membranes & electrocatalysts for PEMFCs that will enable operation under ever more demanding automotive operating conditions & the use high volume compatible processes for their manufacture. Higher performing & more durable electrocatalysts must be developed for PEMFCs to meet the power density & lifetime hours required for FC vehicles. At the same time the amount of expensive Pt catalyst must be reduced to lower the MEA costs. While these two properties are met, the catalyst must be made resistant to multiple degradation mechanisms to reach necessary operating lifetimes. In this report, we present the work focused on the development of a completely new approach to PEMFC electrocatalyts, called nanostructured thin film (NSTF) catalysts. The carbon black supports are eliminated with this new approach which eliminates the carbon corrosion issue. The thin film nature of the catalyst significantly improves its robustness against dissolution & grain growth, preserving the surface area. Also, the activity of the NSTF for oxygen reduction is improved by over 500% compared to dispersed Pt catalyts. Finally, the process for fabricating the NSTF catalysts is consistent with high volume roll-good manufacturing & extremely flexible towards the introduction of new catalyst compositions & structures. This report documents the work done to develop new multi-element NSTF catalysts with properties that exceed pure Pt, that are optimized for use with the membranes discussed below, & advance the state-of-the-art towards meeting the DOE 2010 targets for PEMFC electrocatalysts. The work completed advances the understanding of the NSTF catalyst technology, identifies new NSTF

  15. [Effect of injection of enkephalin and bestatin in caudate-putamen on operant conditioning in rats].

    Science.gov (United States)

    Zhang, S Y; Zhang, Y P; Zhang, M L; Qi, H X; Wang, B

    1992-10-01

    Female Wistar rats were trained in a Skinner-box, 30 trials per day in a dark room to establish operant defence conditioning. Training started with a light (15 s), then combined with footshock for further 8 s. When the rats learned to press the key to avoid footshock within 15 s, conditioned response was considered established. After the rats reached a conditioning rate (CR) above 80% for 5 days, cannulae were implanted into caudate-putamen. Two to three days later, Met-enkephalin (MEK) or bestatin (an aminopeptidase inhibitor) was injected bilaterally into caudate-putamen. 30 min, 2 h, 24 h and 48 h after injection, conditioning tests were conducted, with each session consisting of 30 trials. Control experiments were done when 0.9% NaCl (NS) was injected. After injection of NS, CR maintained above 80% in all 4 test sessions. MEK (60 ng/rat) or bestatin (10 micrograms/rat) significantly lowered the CR during the 30 min and 2 h test session. In the latter case, the latency (L) was also prolonged. However both CR and L returned to the control level in the 24 h and 48 h test sessions. Naloxone (2 mg/kg, i.p.) blocked the conditioning-depression effect of bestatin. No significant alteration was seen in locomotor activity after MEK or bestatin injection. The results suggest that enkephalin in caudate-putamen may be involved in the regulation of retrieval of conditioning. Bestatin mimics the effect of MEK on conditioning reflex probably by increasing production of endogenous enkephalin.

  16. Effects of operating conditions on the adhesive strength of Pseudomonas fluorescens biofilms in tubes.

    Science.gov (United States)

    Chen, M J; Zhang, Z; Bott, T R

    2005-06-25

    Understanding the mechanical properties of biofilms, especially the force required to disrupt them and remove them from substrata is very important to development of antibiofouling strategies. In this work, a novel micromanipulation technique with a specially designed T-shaped probe has been developed to serve as an experimental means to measure directly the adhesive strength of biofouling deposits on the surface of a glass test stud. The basic principle of this novel technique is to pull away a whole biofilm accumulated on the surface of a glass test stud with T-shaped probe, and to measure simultaneously the force imposed on the biofilm. The adhesive strength between the biofilms and the surface to which they are attached, is defined as the work per unit area required to remove the biofilms from the surface. The biofouling experiments were performed on an elaborate design of a simulated heat exchanger system. A monoculture of Pseudomonas fluorescens was chosen as the fouling microorganism for the laboratory studies. Results indicate that the adhesive strength of the biofilm was affected by the conditions of operation, such as biofilm age, nutrient concentration, suspended cell concentration, pH, surface roughness of the substratum and fluid velocity. As noted, the effect of fluid velocity on the biofilm adhesive strength seemed to overwhelm other factors. At the same operating conditions, the biofilm adhesive strength increased as the fluid velocity increased within the range of 0.6-1.6m/s. In addition, the flow-related biofilm structures were observed that biofilms generally grew as a more compact pattern at the higher fluid velocity. Apparently, the fluid velocity can affect the biofilm structure, which in turn determines the biofilm adhesive strength. The knowledge of the biofilm adhesive strength with associated influences of the operating conditions may be used to define better cleaning procedures.

  17. Safe operating conditions for NSLS-II Storage Ring Frontends commissioning

    Energy Technology Data Exchange (ETDEWEB)

    Seletskiy, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Amundsen, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ha, K. [Brookhaven National Lab. (BNL), Upton, NY (United States); Hussein, A. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-04-02

    The NSLS-II Storage Ring Frontends are designed to safely accept the synchrotron radiation fan produced by respective insertion device when the electron beam orbit through the ID is locked inside the predefined Active Interlock Envelope. The Active Interlock is getting enabled at a particular beam current known as AI safe current limit. Below such current the beam orbit can be anywhere within the limits of the SR beam acceptance. During the FE commissioning the beam orbit is getting intentionally disturbed in the particular ID. In this paper we explore safe operating conditions for the Frontends commissioning.

  18. Atmospheric conditions affecting seeing at St. Catherine: Estimation of operational time for NRIAG new telescope

    Science.gov (United States)

    Mekhaimr, Sayed A.

    2017-06-01

    The study of the prevailing atmospheric conditions is an essential part of any site testing for a new telescope establishment. In this article, the meteorological parameters that affect the astronomical seeing at St. Catherine region, where a two candidate sites are located, are studied based on the available climate data. The complex topographical features of the region cause some differences between the weather at the nearest meteorological station and that at the candidate sites. This issue is illustrated through high resolution atmospheric modeling for short period (six days) as a case study. Finally, a preliminary estimation of operational hours for the telescope at the candidate sites is calculated.

  19. The effect of operational conditions on the sludge specific methanogenic activity and sludge biodegradability

    Energy Technology Data Exchange (ETDEWEB)

    Leitao, R. C.; Santaella, S. T.; Haandel, A. C. van; Zeeman, G.; Lettinga, G.

    2009-07-01

    The Specific Methanogenic Activity (SMA) and sludge biodegradability of an anaerobic sludge depends on various operational and environmental conditions imposed to the anaerobic reactor. However, the effects of hydraulic retention time (HRT), influent COD concentration (COD{sub i}nf) and sludge retention time (SRT) on those two parameters need to be elucidated. This knowledge about SMA can provide insights about the capacity of the UASB reactors to withstand organic and hydraulic shock loads, whereas the biodegradability gives information necessary for final disposal of the sludge. (Author)

  20. Lithium-ion battery dynamic model for wide range of operating conditions

    DEFF Research Database (Denmark)

    Stroe, Ana-Irina; Stroe, Daniel-Ioan; Swierczynski, Maciej Jozef

    2017-01-01

    In order to analyze the dynamic behavior of a Lithium-ion (Li-ion) battery and to determine their suitability for various applications, battery models are needed. An equivalent electrical circuit model is the most common way of representing the behavior of a Li-ion battery. There are different...... characterization tests performed for a wide range of operating conditions (temperature, load current and state-ofcharge) on a commercial available 13Ah high-power lithium titanate oxide battery cell. The obtained results were used to parametrize the proposed dynamic model of the battery cell. To assess...

  1. Using operant conditioning and desensitization to facilitate veterinary care with captive reptiles.

    Science.gov (United States)

    Hellmuth, Heidi; Augustine, Lauren; Watkins, Barbara; Hope, Katharine

    2012-09-01

    In addition to being a large component of most zoological collections, reptile species are becoming more popular as family pets. Reptiles have the cognitive ability to be trained to facilitate daily husbandry and veterinary care. Desensitization and operant conditioning can alleviate some of the behavioral and physiological challenges of treating these species. A survey of reptile training programs at zoos in the United States and worldwide reveals that there are many successful training programs to facilitate veterinary care and minimize stress to the animal. Many of the techniques being used to train reptiles in zoological settings are transferable to the exotic pet clinician.

  2. Effect of magnetic field on the behavior of operantly conditioned mice

    Energy Technology Data Exchange (ETDEWEB)

    Brannon, T..; Williams, M.C.; Ward, S.

    1988-01-01

    Two mice were trained to run a T-shaped maze. One mouse was trained to turn right while the other mouse was trained to turn left. A magnetic field was then set up in the arm of the maze to which the mouse had been trained to turn. The mice were allowed to run the maze and scored on the basis of their correct response. The scores of both mice were significantly lower when the magnetic field was present, thus indicating interference by the magnetic field on their operant conditioning.

  3. Study on Optimum Extracting Conditions of Total Polysaccharides from Ganoderma lucidum of Lingdan Capsule by Alkaline Solutions%碱水提取复方灵丹胶囊中灵芝多糖的工艺

    Institute of Scientific and Technical Information of China (English)

    叶豆丹; 孟美; 王化宇; 任钰; 张炜煜

    2014-01-01

    试验优选了碱水提取法提取复方灵丹胶囊中灵芝多糖的最佳工艺。以总多糖的含量为考察指标,采用单因素法和正交试验法确定方中灵芝多糖最佳提取工艺。结果最佳提取工艺为加10倍于药材量的水(pH=9)煎煮2次,每次1.0 h。该提取工艺操作简单、稳定可行,适合于产业化生产,并具有良好的应用前景。%To optimize the extraction technology of effective fraction of Ganoderma lucidum. To regard the contents of total polysaccharides as the examinational indicators, to decide the extraction methods by L9 (34) orthogonal test and single factor method for total polysaccharides components of Ganoderma lucidum. The optimal extraction of total polysaccharides in Ganoderma lucidum is medicinal materials plus 10 times the amount of water (pH=9), extract twice and 1.0 h per time. The optimum extraction technology of total polysaccharides from Ganoderma lucidum is simple, stable and feasible, suitable for industrial production, and has a good prospect.

  4. 杏皮渣白兰地酒精发酵最佳工艺条件的研究%Study on the Optimum Alcohol Fermentation Conditions in Apricot Peel Brandy Production

    Institute of Scientific and Technical Information of China (English)

    何伟; 张富县; 艾乃吐拉; 傅力

    2011-01-01

    以杏皮渣为原料,研究杏皮渣白兰地生产中酒精发酵阶段的主要工艺条件。对杏皮渣浆液的制备方式、最佳酵母的筛选、接种量、初始含糖量、发酵温度、初始pH以及在发酵过程中酒精度和残糖的变化进行了研究。结果表明,杏皮渣浆的最佳制取方式采用高压蒸煮和酶解结合法:将杏皮渣和水按1:6浸泡2h后破碎打浆,121℃高压蒸煮10min,冷却到室温后加入杏皮渣重量0.5%的果胶酶和1.5%的纤维素酶,在50℃下酶解4h,得到的杏皮渣浆的还原糖含量为72.27g/L。杏皮渣酒精发酵最佳工艺条件为:采用杏酒酵母N016,接种量为3%,初始合糖量为250g/L,发酵温度为28℃,初始pH3.9,发酵时间为12d,酒精度可以达到11.2%vol。%The main technical conditions in alcohol fermentation stage in apricot peel brandy production were studied. The preparation of apricot peel pulp, the selection of suitable yeast, inoculating quantity, initial sugar content, fermentation temperature, initial pH value and the change of alcoholicity and residual sugar content in alcohol fermentation process were investigated. The results showed that apricot peel pulp was prepared through the combination of high pressure cooking and enzymolysis as follows: the ratio of apricot peel and water was 1:6, after 2 h steeping, breaking and pulping operated, and then 10 rain high pressure cooking and steaming at 121 ~C, after cooling at room temperature, pectinase (0.5 % of apricot peel weight) and cellulase (1.5 % of apricot peel weight) were added, after 4 h enzymolysis at 50 ℃, apricot peel pulp was finally produced with its reducing sugar content as 72.27 g/L. The best technical conditions for alcohol fermentation were summed up as follows: Nol6 yeast was used, the inoculating quantity was 3 %, initial sugar content was 250 g/L, fermentation temperature was at 28 ℃, initial pH value was 3

  5. Operating conditions and stability of spin torque majority gates: Analytical understanding and numerical evidence

    Science.gov (United States)

    Vaysset, Adrien; Manfrini, Mauricio; Nikonov, Dmitri E.; Manipatruni, Sasikanth; Young, Ian A.; Radu, Iuliana P.; Thean, Aaron

    2017-01-01

    The functionality of a cross-shaped Spin Torque Majority Gate (STMG) is primarily limited by the pinning of a domain wall (DW) at the center of the device. Here, an analytical model is built to calculate the conditions for such a pinning and to deduce the operating range. The assumptions of the model and the conclusions are validated by micromagnetic simulations. The total magnetic energy of the DW state is derived. By minimizing this energy with respect to two degrees of freedom, the DW stability condition is obtained. We find that the lateral length of the STMG is the critical dimension: it must be smaller than about five times the DW width. This result is confirmed by micromagnetic simulations with a high accuracy. In process, we solved a more fundamental problem: the macrospin limit of a finite ferromagnet containing one pinning site. We found the correction of the usual DW width expression due to finite length of wires.

  6. Key Parameters for Operator Diagnosis of BWR Plant Condition during a Severe Accident

    Energy Technology Data Exchange (ETDEWEB)

    Clayton, Dwight A [ORNL; Poore III, Willis P [ORNL

    2015-01-01

    The objective of this research is to examine the key information needed from nuclear power plant instrumentation to guide severe accident management and mitigation for boiling water reactor (BWR) designs (specifically, a BWR/4-Mark I), estimate environmental conditions that the instrumentation will experience during a severe accident, and identify potential gaps in existing instrumentation that may require further research and development. This report notes the key parameters that instrumentation needs to measure to help operators respond to severe accidents. A follow-up report will assess severe accident environmental conditions as estimated by severe accident simulation model analysis for a specific US BWR/4-Mark I plant for those instrumentation systems considered most important for accident management purposes.

  7. Adaptive strategies of remote systems operators exposed to perturbed camera-viewing conditions

    Science.gov (United States)

    Stuart, Mark A.; Manahan, Meera K.; Bierschwale, John M.; Sampaio, Carlos E.; Legendre, A. J.

    1991-01-01

    This report describes a preliminary investigation of the use of perturbed visual feedback during the performance of simulated space-based remote manipulation tasks. The primary objective of this NASA evaluation was to determine to what extent operators exhibit adaptive strategies which allow them to perform these specific types of remote manipulation tasks more efficiently while exposed to perturbed visual feedback. A secondary objective of this evaluation was to establish a set of preliminary guidelines for enhancing remote manipulation performance and reducing the adverse effects. These objectives were accomplished by studying the remote manipulator performance of test subjects exposed to various perturbed camera-viewing conditions while performing a simulated space-based remote manipulation task. Statistical analysis of performance and subjective data revealed that remote manipulation performance was adversely affected by the use of perturbed visual feedback and performance tended to improve with successive trials in most perturbed viewing conditions.

  8. Determination of materials and cutting conditions in a CNC lathe turning operation

    Directory of Open Access Journals (Sweden)

    Juan Bautista Hernández-Granados

    2014-05-01

    Full Text Available One of the main problems of machining can be described as the achievement of a predefined product quality with given working conditions. The turning operation on Sistemas Integrados de Manufactura (SIMTEC Laboratory has been stu-died with diffe-rent cutting conditions (feed, depth of cut, rpm and material type (Aluminum 6061, Steel 1020 to identify the combination and level factors that improve the surface roughness in a work piece. Using three of Design of Experiments techniques (DOE, such as factorial design, multiple linear regression and response surface methodo-logy (RSM we identified the factors and levels that reduce the surface roughness and these are the feed rate = 50 mm/min, rpm = 1200 and aluminum material. A first-order model has been established between the cutting parameters and surface roughness which can be used together with the RMS graph to predict an average roughness value.

  9. Experimental Evaluation of the Surface Alteration of Gasket Samples under Operative Conditions

    Directory of Open Access Journals (Sweden)

    M.C. Bignozzi

    2015-12-01

    Full Text Available This paper investigates the surface alteration of gasket samples commercialized by two alternative producers. These gaskets, in polymeric materials, are installed in process plants used for cleaning tires molds by a pioneering ultrasonic process. They are exposed to a combination of ultrasonic waves, temperature, humidity and acid attack causing several erosion phenomena. Their surface degradation under ordinary operative conditions was investigated using mechanical and tribological tests. The experimental characterization was performed by optical microscopy, scanning electron microscopy, thermograms, differential scanning calorimetry curves and infrared spectra aiming at defining the specific mechanics of wearing. As a conclusion, it was possible to state that even if samples exhibit similar chemical structures, their thermal and mechanical properties as well as their geometric dimensions are different. Such differences in the materials might cause various unexpected wear behaviors when gaskets are employed in the same working conditions.


  10. A Weekly Indicator of Surface Moisture Status from Satellite Data for Operational Monitoring of Crop Conditions

    Directory of Open Access Journals (Sweden)

    Francesco Nutini

    2017-06-01

    Full Text Available The triangle method has been applied to derive a weekly indicator of evaporative fraction on vegetated areas in a temperate region in Northern Italy. Daily MODIS Aqua Land Surface Temperature (MYD11A1 data has been combined with air temperature maps and 8-day composite MODIS NDVI (MOD13Q1/MYD13Q1 data to estimate the Evaporative Fraction (EF at 1 km resolution, on a daily basis. Measurements at two eddy covariance towers located within the study area have been exploited to assess the reliability of satellite based EF estimations as well as the robustness of input data. Weekly syntheses of the daily EF indicator (EFw were then derived at regional scale for the years 2010, 2011 and 2012 as a proxy of overall surface moisture condition. EFw showed a temporal behavior consistent with growing cycles and agro-practices of the main crops cultivated in the study area (rice, forages and corn. Comparison with official regional corn yield data showed that variations in EFw cumulated over summer are related with crop production shortages induced by water scarcity. These results suggest that weekly-averaged EF estimated from MODIS data is sensible to water stress conditions and can be used as an indicator of crops’ moisture conditions at agronomical district level. Advantages and disadvantages of the proposed approach to provide information useful to issue operational near real time bulletins on crop conditions at regional scale are discussed.

  11. Differential rearing conditions and alcohol-preferring rats: consumption of and operant responding for ethanol.

    Science.gov (United States)

    Deehan, Gerald A; Palmatier, Matthew I; Cain, Mary E; Kiefer, Stephen W

    2011-04-01

    Exposing rats to differential rearing conditions during early postweaning development has been shown to produce changes in a number of behaviors displayed during adulthood. The purpose of the present studies was to investigate whether rearing alcohol-preferring (P) and nonpreferring (NP) rats in an environmental enrichment condition (EC), a social condition (SC), or an impoverished condition (IC) would differentially affect self-administration of 10% ethanol. In Experiment 1, rats were tested for consumption of 10% ethanol in limited- and free-access tests. For Experiment 2, rats were trained to respond in an operant chamber for ethanol and then provided concurrent access to 10% ethanol and water. Each solution was presented in a separate liquid dipper after meeting the schedule of reinforcement on distinct levers. After concurrent access tests, the water lever/dipper was inactivated and a progressive ratio (PR) schedule was initiated. Three successive solutions (10% ethanol, 15% ethanol, and 10% sucrose) were tested under the PR. For P rats, rearing in an EC reduced ethanol consumption, preference, and motivation to obtain ethanol, relative to P rats reared in an IC. Thus, exposure to a novel environment immediately after weaning acted to decrease the reinforcing properties of ethanol in an animal model for alcoholism.

  12. Optimum Onager: The Classical Mechanics of a Classical Siege Engine

    Science.gov (United States)

    Denny, Mark

    2009-01-01

    The onager is a throwing weapon of classical antiquity, familiar to both the ancient Greeks and Romans. Here we analyze the dynamics of onager operation and derive the optimum angle for launching a projectile to its maximum range. There is plenty of scope for further considerations about increasing onager range, and so by thinking about how this…

  13. Optimum design of Nd-doped fiber optical amplifiers

    DEFF Research Database (Denmark)

    Rasmussen, Thomas; Bjarklev, Anders Overgaard; Lumholt, Ole

    1992-01-01

    The waveguide parameters for a Nd-doped fluoride (Nd:ZBLANP) fiber amplifier have been optimized for small-signal and booster operation using an accurate numerical model. The optimum cutoff wavelength is shown to be 800 nm and the numerical aperture should be made as large as possible. Around 80...

  14. Slide Valves for Single-Screw Expanders Working Under Varied Operating Conditions

    Directory of Open Access Journals (Sweden)

    Yuting Wu

    2016-06-01

    Full Text Available This paper fully describes the working principle of slide valves in single-screw expanders (SSEs. A geometric analysis of suction and volume ratio slide valves is presented to determine the relations between volume ratio, suction closure volume, discharge opening volume and slide valves displacement. An organic Rankine cycle (ORC thermodynamic model with SSE integrated with slide valves is developed to analyze the power output of SSE and the net power output of ORC system and variation law of slide valves displacement. Analysis of a typical ORC system under changing operating conditions shows that the power output of the expander and the net output power of the ORC system with slide valves are much better than those without slide valves. When the condensing temperature is 40 °C and the waste availability is 80 kW, the increase in output power and net output power are approximately 3.4 kW and 5 kW, respectively. The presented geometric analysis of slide valves and the thermodynamic model integrated with slide valves can be used to provide a theoretical and technical basis for designing the slide valves of SSEs and the control strategies of slide valves under varied operating conditions.

  15. Effects of operating conditions on THMs and HAAs formation during wastewater chlorination

    Energy Technology Data Exchange (ETDEWEB)

    Sun Yingxue; Wu Qianyuan [Environmental Simulation and Pollution Control State Key Joint Laboratory, Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084 (China); Hu Hongying, E-mail: hyhu@tsinghua.edu.cn [Environmental Simulation and Pollution Control State Key Joint Laboratory, Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084 (China); Tian Jie [Environmental Simulation and Pollution Control State Key Joint Laboratory, Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2009-09-15

    Disinfection is the last barrier of wastewater reclamation process to protect ecosystem safety and human health. However, the chlorination process results in the formation of mutagenic/carcinogenic disinfection by-products (DBPs) deriving from the reaction of the chlorine with organic compounds in wastewater. The effects of operating conditions (chlorine dose, contact time, reaction temperature and pH value) of chlorination on the formation of trihalomethanes (THMs) and haloacetic acids (HAAs) in biologically treated wastewater samples were investigated in this study. The results indicated that the total THMs (TTHM) and total HAAs (THAA) increased exponentially with increasing chlorine dose, but there are discrepancies between the formation rates of TTHM and THAA. The THAA reached a peak at contact time of 2 h and thereafter decreased with extended time. The formation time of THMs depends on the wastewater content of quick or slow formers. The yields of bromated HAAs (as MBAA, BCAA, and BDCAA) would decrease markedly after the contact time over 2 h during wastewater chlorination, and were favored in low pH values of 4 and high pH values of 9 under certain contact time. In addition, the formation of MBAA, BCAA, BDCAA decreased gradually as reaction temperature increased from 4 to 30 deg. C in the chlorination of wastewater containing a certain concentration of bromide. The effects of operating conditions on THMs and HAAs formation during wastewater chlorination were completely different from those of surface water disinfection.

  16. Review of Operational Challenges and Changing Conditions associated with Offshore Submerged Vertical Pumping Station

    Science.gov (United States)

    Samsudin, M. L.; Munisamy, K. M.; Thangaraju, S. K.

    2015-09-01

    Cooling water system is one of the essential auxiliary systems for a power generating plant. The decision to have an offshore pumping station, instead of onshore station, may have been driven by the scarcity in land area or for direct water supply access. However, the design has several disadvantages such as tendency for sediment intakes, limited condition monitoring activities and inaccessible sump for maintenance and modification. The paper reviews and lists several potential operational challenges and difficulties experienced with the offshore station. The influences of changing conditions such as varying seawater tide level, clogged intake screen, intake sedimentation issues and marine fouling on the sump walls and structures, are discussed and mitigating solutions are identified. While it is impractical to conduct physical model test for studying flow pattern, the CFD method can be an attractive assessment tools. In addition to this, a review of plant operating parameters can assist in identifying flow anomalies to anticipate potential deterioration. Finally the difficulty in incorporating the solutions to vortex and sediment problems within the sump is highlighted with preference for those which can be managed by limited access or those which are moveable with the vertical pump.

  17. Current Conditions Risk Assessment for the 300-FF-5 Groundwater Operable Unit

    Energy Technology Data Exchange (ETDEWEB)

    Miley, Terri B.; Bunn, Amoret L.; Napier, Bruce A.; Peterson, Robert E.; Becker, James M.

    2007-11-01

    This report updates a baseline risk assessment for the 300 Area prepared in 1994. The update includes consideration of changes in contaminants of interest and in the environment that have occurred during the period of interim remedial action, i.e., 1996 to the present, as well as the sub-regions, for which no initial risk assessments have been conducted. In 1996, a record of decision (ROD) stipulated interim remedial action for groundwater affected by releases from 300 Area sources, as follows: (a) continued monitoring of groundwater that is contaminated above health-based levels to ensure that concentrations continue to decrease, and (b) institutional controls to ensure that groundwater use is restricted to prevent unacceptable exposure to groundwater contamination. In 2000, the groundwater beneath the two outlying sub-regions was added to the operable unit. In 2001, the first 5-year review of the ROD found that the interim remedy and remedial action objectives were still appropriate, although the review called for additional characterization activities. This report includes a current conditions baseline ecological and human health risk assessment using maximum concentrations in the environmental media of the 300-FF-5 Operable Unit and downstream conditions at the City of Richland, Washington. The scope for this assessment includes only current measured environmental concentrations and current use scenarios. Future environmental concentrations and future land uses are not considered in this assessment.

  18. Aerodynamic performance of a vibrating piezoelectric fan under varied operational conditions

    Science.gov (United States)

    Stafford, J.; Jeffers, N.

    2014-07-01

    This paper experimentally examines the bulk aerodynamic performance of a vibrating fan operating in the first mode of vibration. The influence of operating condition on the local velocity field has also been investigated to understand the flow distribution at the exit region and determine the stalling condition for vibrating fans. Fan motion has been generated and controlled using a piezoelectric ceramic attached to a stainless steel cantilever. The frequency and amplitude at resonance were 109.4 Hz and 12.5 mm, respectively. A test facility has been developed to measure the pressure-flow characteristics of the vibrating fan and simultaneously conduct local velocity field measurements using particle image velocimetry. The results demonstrate the impact of system characteristics on the local velocity field. High momentum regions generated due to the oscillating motion exist with a component direction that is tangent to the blade at maximum displacement. These high velocity zones are significantly affected by increasing impedance while flow reversal is a dominant feature at maximum pressure rise. The findings outlined provide useful information for design of thermal management solutions that may incorporate this air cooling approach.

  19. Investigation of a High Head Francis Turbine at Runaway Operating Conditions

    Directory of Open Access Journals (Sweden)

    Chirag Trivedi

    2016-03-01

    Full Text Available Hydraulic turbines exhibit total load rejection during operation because of high fluctuations in the grid parameters. The generator reaches no-load instantly. Consequently, the turbine runner accelerates to high speed, runaway speed, in seconds. Under common conditions, stable runaway is only reached if after a load rejection, the control and protection mechanisms both fail and the guide vanes cannot be closed. The runner life is affected by the high amplitude pressure loading at the runaway speed. A model Francis turbine was used to investigate the consequences at the runaway condition. Measurements and simulations were performed at three operating points. The numerical simulations were performed using standard k-ε, k-ω shear stress transport (SST and scale-adaptive simulation (SAS models. A total of 12.8 million hexahedral mesh elements were created in the complete turbine, from the spiral casing inlet to the draft tube outlet. The experimental and numerical analysis showed that the runner was subjected to an unsteady pressure loading up to three-times the pressure loading observed at the best efficiency point. Investigates of unsteady pressure pulsations at the vaneless space, runner and draft tube are discussed in the paper. Further, unsteady swirling flow in the blade passages was observed that was rotating at a frequency of 4.8-times the runaway runner angular speed. Apart from the unsteady pressure loading, the development pattern of the swirling flow in the runner is discussed in the paper.

  20. Validation and Verification of Future Integrated Safety-Critical Systems Operating under Off-Nominal Conditions

    Science.gov (United States)

    Belcastro, Christine M.

    2010-01-01

    Loss of control remains one of the largest contributors to aircraft fatal accidents worldwide. Aircraft loss-of-control accidents are highly complex in that they can result from numerous causal and contributing factors acting alone or (more often) in combination. Hence, there is no single intervention strategy to prevent these accidents and reducing them will require a holistic integrated intervention capability. Future onboard integrated system technologies developed for preventing loss of vehicle control accidents must be able to assure safe operation under the associated off-nominal conditions. The transition of these technologies into the commercial fleet will require their extensive validation and verification (V and V) and ultimate certification. The V and V of complex integrated systems poses major nontrivial technical challenges particularly for safety-critical operation under highly off-nominal conditions associated with aircraft loss-of-control events. This paper summarizes the V and V problem and presents a proposed process that could be applied to complex integrated safety-critical systems developed for preventing aircraft loss-of-control accidents. A summary of recent research accomplishments in this effort is also provided.

  1. Coexistence of reward and unsupervised learning during the operant conditioning of neural firing rates.

    Directory of Open Access Journals (Sweden)

    Robert R Kerr

    Full Text Available A fundamental goal of neuroscience is to understand how cognitive processes, such as operant conditioning, are performed by the brain. Typical and well studied examples of operant conditioning, in which the firing rates of individual cortical neurons in monkeys are increased using rewards, provide an opportunity for insight into this. Studies of reward-modulated spike-timing-dependent plasticity (RSTDP, and of other models such as R-max, have reproduced this learning behavior, but they have assumed that no unsupervised learning is present (i.e., no learning occurs without, or independent of, rewards. We show that these models cannot elicit firing rate reinforcement while exhibiting both reward learning and ongoing, stable unsupervised learning. To fix this issue, we propose a new RSTDP model of synaptic plasticity based upon the observed effects that dopamine has on long-term potentiation and depression (LTP and LTD. We show, both analytically and through simulations, that our new model can exhibit unsupervised learning and lead to firing rate reinforcement. This requires that the strengthening of LTP by the reward signal is greater than the strengthening of LTD and that the reinforced neuron exhibits irregular firing. We show the robustness of our findings to spike-timing correlations, to the synaptic weight dependence that is assumed, and to changes in the mean reward. We also consider our model in the differential reinforcement of two nearby neurons. Our model aligns more strongly with experimental studies than previous models and makes testable predictions for future experiments.

  2. Effects of Operating Conditions on Internal Resistances in Enzyme Fuel Cells Studied via Electrochemical Impedance Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Aaron, D [Georgia Institute of Technology; Borole, Abhijeet P [ORNL; Yiacoumi, Sotira [Georgia Institute of Technology; Tsouris, Costas [ORNL

    2012-01-01

    Enzyme fuel cells (EFCs) offer some advantages over traditional precious-metal-catalyzed fuel cells, such as polymer electrolyte membrane fuel cells (PEMFCs). However, EFCs exhibit far less power output than PEMFCs and have relatively short life spans before materials must be replaced. In this work, electrochemical impedance spectroscopy (EIS) is used to analyze the internal resistances throughout the EFC at a variety of operating conditions. EIS analysis is focused primarily on the resistances of the anode, solution/membrane, and cathode. Increased enzyme loading results in improved power output and reductions in internal resistance. Conditions are identified for which enzyme loading does not limit the EFC performance. EIS experiments are also reported for EFCs operated continuously for 2 days; power output declines sharply over time, while all internal resistances increase. Drying of the cathode and enzyme/mediator degradation are believed to have contributed to this behavior. Finally, experiments are performed at varying air-humidification temperatures. Little effect on internal resistances or power output is observed. However, it is anticipated that increased air humidification can improve longevity by delivering more water to the cathode. Improvements to the enzymatic cathode are needed for EFC development. These improvements need to focus on improving transport rather than increasing enzyme loading.

  3. Impacts of operating conditions on nanofiltration of secondary-treated two-phase olive mill wastewater.

    Science.gov (United States)

    Ochando Pulido, Javier Miguel; Martínez Férez, Antonio

    2015-09-15

    In the present paper, a thin-film composite polymeric nanofiltration (NF) membrane is examined for the tertiary treatment of secondary-treated two-phase olive mill wastewater, in substitution of the reverse osmosis membrane used in previous work by the Authors. Overcoming the deleterious fouling phenomena persistently encountered in membrane processes managing wastewater streams was indeed pursued. Setting the adequate parameters of the operating variables - that is, operating at ambient temperature upon a net pressure equal to 13 bar (Pc), tangential crossflow in the order of 2.55 m s(-1) to attain enough turbulence over the membrane, and above the point of zero charge (pH > 5.8) of the membrane - ensured high steady-state permeate productivity (59.6 L h(-1) m(-2)), also economically sustainable in time owed to minimization of the fouling-build up rate (0.91 h(-1)). Moreover, these conditions also provided high feed recovery (90%) and significant rejection efficiencies for the electroconductivity (58.1%) and organic matter (76.1%). This led to a purified permeate stream exiting the NF membrane operation exhibiting average EC and COD values equal to 1.4 mS cm(-1) and 45 mg L(-1). This permits complying with the water quality parameters established by different regulations for discharge public waterways and irrigation purposes.

  4. Numerical Simulation and Validation of a High Head Model Francis Turbine at Part Load Operating Condition

    Science.gov (United States)

    Goyal, Rahul; Trivedi, Chirag; Kumar Gandhi, Bhupendra; Cervantes, Michel J.

    2017-07-01

    Hydraulic turbines are operated over an extended operating range to meet the real time electricity demand. Turbines operated at part load have flow parameters not matching the designed ones. This results in unstable flow conditions in the runner and draft tube developing low frequency and high amplitude pressure pulsations. The unsteady pressure pulsations affect the dynamic stability of the turbine and cause additional fatigue. The work presented in this paper discusses the flow field investigation of a high head model Francis turbine at part load: 50% of the rated load. Numerical simulation of the complete turbine has been performed. Unsteady pressure pulsations in the vaneless space, runner, and draft tube are investigated and validated with available experimental data. Detailed analysis of the rotor stator interaction and draft tube flow field are performed and discussed. The analysis shows the presence of a rotating vortex rope in the draft tube at the frequency of 0.3 times of the runner rotational frequency. The frequency of the vortex rope precession, which causes severe fluctuations and vibrations in the draft tube, is predicted within 3.9% of the experimental measured value. The vortex rope results pressure pulsations propagating in the system whose frequency is also perceive in the runner and upstream the runner.

  5. Impact of operating conditions on the removal of endocrine disrupting chemicals by membrane photocatalytic reactor.

    Science.gov (United States)

    López Fernández, Raquel; Coleman, Heather M; Le-Clech, Pierre

    2014-08-01

    This study focuses on the performance of a submerged membrane photocatalytic reactor for the removal of 17beta-oestradiol (E2) in the presence of humic acid (HA). In addition to the impact of operating parameters, such as membrane pore size, ultraviolet (UV) intensity and hydraulic retention time (HRT), the influence of long-term operation was also assessed by advanced characterization of the fouling layer formed on the membrane. The tighter (0.04 microm) hollow fibre polyvinylydene fluoride (PVDF) membrane was found to exhibit not only higher HA removal than the (0.2 microm) module (85% and 75%, respectively), but also greater transmembrane pressure (TMP) values and higher irreversible fouling. Long-term operation conditions have been simulated by conducting an ageing catalyst process and demonstrated a decrease in performance obtained with time. The artificially aged TiO2 resulted in higher TMP values and lower HA removals (about 10-20% decrease) compared with the non-aged catalyst. For E2 removal in the presence of HA, the passive adsorption of the oestrogen onto the organic matter was found to be significant (40% of the E2 adsorbed after I h), demonstrating the importance of the nature of the water matrix for this type of treatment process. An increase in the UV light intensity was observed to favour the E2 elimination, leading to more than 90% removal when using 64 W combined with PVDF membrane and an HRT of 3 h.

  6. Analysis of electric energy consumption of automatic milking systems in different configurations and operative conditions.

    Science.gov (United States)

    Calcante, Aldo; Tangorra, Francesco M; Oberti, Roberto

    2016-05-01

    Automatic milking systems (AMS) have been a revolutionary innovation in dairy cow farming. Currently, more than 10,000 dairy cow farms worldwide use AMS to milk their cows. Electric consumption is one of the most relevant and uncontrollable operational cost of AMS, ranging between 35 and 40% of their total annual operational costs. The aim of the present study was to measure and analyze the electric energy consumption of 4 AMS with different configurations: single box, central unit featuring a central vacuum system for 1 cow unit and for 2 cow units. The electrical consumption (daily consumption, daily consumption per cow milked, consumption per milking, and consumption per 100L of milk) of each AMS (milking unit + air compressor) was measured using 2 energy analyzers. The measurement period lasted 24h with a sampling frequency of 0.2Hz. The daily total energy consumption (milking unit + air compressor) ranged between 45.4 and 81.3 kWh; the consumption per cow milked ranged between 0.59 and 0.99 kWh; the consumption per milking ranged between 0.21 and 0.33 kWh; and the consumption per 100L of milk ranged between 1.80 to 2.44 kWh according to the different configurations and operational contexts considered. Results showed that AMS electric consumption was mainly conditioned by farm management rather than machine characteristics/architectures. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  7. National Utilization Patterns of Steroid Injection and Operative Intervention for Treatment of Common Hand Conditions

    Science.gov (United States)

    Sears, Erika D.; Swiatek, Peter R.; Chung, Kevin C

    2015-01-01

    Purpose To conduct a population-level analysis of practice trends and probability of surgery based on the number of steroid injections for common hand conditions. Methods Patients at least 18 years old receiving injection or surgery for carpal tunnel syndrome (CTS), trigger finger (TF), or De Quervain tenovaginitis (DQ) were identified for inclusion using the 2009–2013 Truven MarketScan databases. The number of injections performed was counted, and time between injection and operation was calculated for patients receiving both treatments. A multivariable logistic regression model was created to evaluate the odds of undergoing surgery based on the number of injections performed, controlling for patient age, sex, comorbidities, and insurance type. Results The study sample included 251,030 patients who underwent steroid injection or operative release for CTS (n=129,917), TF (n=102,778), and DQ (n=18,335). The majority of CTS patients were managed with immediate surgery (71%), whereas most patients with TF and DQ were managed initially with injection (74% and 84%, respectively). Among patients receiving both an injection and an operation, a single injection was the most common practice prior to surgery (69%, 58%, and 67% of patients with CTS, TF, and DQ, respectively). Multiple injections for DQ and TF were associated with relatively low predicted probability of surgery (17% and 26%, respectively, after 2 injections). However, the predicted probability of surgery after two injections was higher in patients with CTS (44%). Conclusions Given the associated probability of surgery after multiple injections for the three hand conditions examined, the practice of repeat injections should be critically examined to determine whether underuse or overuse is present and whether efficiency and resource utilization can be improved upon. Level of Evidence Level II (retrospective prognostic study) PMID:26774548

  8. Modal Testing and Analysis of Structures Under Operational Conditions: Industrial Applications

    Science.gov (United States)

    Hermans, L.; van der Auweraer, H.

    1999-03-01

    Experimental identification of structural dynamics models is usually based on the modal analysis approach. In the classical modal parameter estimation approach, the baseline data which are processed are frequency response functions measured under laboratory conditions. However, in many applications, the real operating conditions may differ significantly from those applied during the modal test. Hence, the need arises to identify a modal model in operational conditions. This issue is even more complicated by the fact that in most cases, only response data are measurable while the actual loading conditions are unknown. Therefore, the system identification process will need to base itself on output-only data. In the last decade, the problem of output-only modal analysis has typically been approached by applying a peak-picking technique to the auto- and cross-powers of the measured responses, resulting in operational deflection shapes and approximate estimates for the resonance frequencies. These shapes were then compared to or even decomposed into the laboratory modal results. Over the past years, several modal parameter estimation techniques have been proposed and studied for modal parameter extraction from output-only data. They include autoregressive moving averaging models, natural excitation technique (NExT) and stochastic subspace methods. In this paper, the capabilities and limitations of the NExT technique and two subspace techniques, referred to as the balanced realization and the canonical variate analysis, are evaluated for its applicability to industrial cases. The theory of the methods is briefly outlined. Subsequently, the performance of the methods is critically evaluated and compared for three industrial cases: the modal characterisation of the rear suspension system of a family car during road tests in order to understand a booming noise problem, flight flutter analysis of a commercial aircraft and the identification of the modes of a three

  9. Final Report - Membranes and MEA's for Dry, Hot Operating Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Hamrock, Steven J

    2011-06-30

    The focus of this program was to develop a new Proton Exchange Membrane (PEM) which can operate under hotter, dryer conditions than the state of the art membranes today and integrate it into a Membrane Electrode Assembly (MEA). These MEA's should meet the performance and durability requirements outlined in the solicitation, operating under low humidification conditions and at temperatures ranging from -20ºC to 120ºC, to meet 2010 DOE technical targets for membranes. This membrane should operate under low humidification conditions and at temperatures ranging from -20ºC to 120ºC in order to meet DOE HFCIT 2010 commercialization targets for automotive fuel cells. Membranes developed in this program may also have improved durability and performance characteristics making them useful in stationary fuel cell applications. The new membranes, and the MEA's comprising them, should be manufacturable at high volumes and at costs which can meet industry and DOE targets. This work included: A) Studies to better understand factors controlling proton transport within the electrolyte membrane, mechanisms of polymer degradation (in situ and ex situ) and membrane durability in an MEA; B) Development of new polymers with increased proton conductivity over the range of temperatures from -20ºC to 120ºC and at lower levels of humidification and with improved chemical and mechanical stability; C) Development of new membrane additives for increased durability and conductivity under these dry conditions; D) Integration of these new materials into membranes and membranes into MEA's, including catalyst and gas diffusion layer selection and integration; E) Verification that these materials can be made using processes which are scalable to commercial volumes using cost effective methods; F) MEA testing in single cells using realistic automotive testing protocols. This project addresses technical barriers A (Durability) and C (Performance) from the Fuel Cells section of the

  10. Standardization of the energy performance of photovoltaic modules in real operating conditions

    Directory of Open Access Journals (Sweden)

    Viganó Davide

    2014-01-01

    Full Text Available The performance of a PV module at STC [1] is a useful indicator for comparing the peak performance of different module types, but on its own is not sufficient to accurately predict how much energy a module will deliver in the field when subjected to a wide range of real operating conditions [2]. An Energy Rating approach has to be preferred for that aim. It is currently under development the standard series IEC 61853 on Energy Rating, for which only part 1 [3] has been issued. It describes methods to characterize the module performance as a function of irradiance and temperature. The reproducibility of the power matrix measurements obtained by the three different methods specified in the standard, namely: under natural sunlight using a tracking system; under natural sunlight without tracker; and a large area pulsed solar simulator of Class AAA were evaluated and discussed [4,5]. The work here presented is focused on the second method listed above, which explores the real working conditions for a PV device and therefore it represents the situation where Energy Rating procedures are expected to give the largest deviations from the STC predictions. The system for continuous monitoring of module performances, already implemented at ESTI, has been recently replaced with a new system having a number of improvements described in the following. The two system results have been compared showing a discrete compatibility. The two power matrices are then merged together using a weighted average and compared to those acquired with the other two remaining “ideal” systems. An interesting tendency seems to come up from this comparison, making the power rating under real operating conditions an essential procedure for energy rating purposes.

  11. Combining models of behaviour with operational data to provide enhanced condition monitoring of AGR cores

    Energy Technology Data Exchange (ETDEWEB)

    West, Graeme M., E-mail: graeme.west@strath.ac.uk; Wallace, Christopher J.; McArthur, Stephen D.J.

    2014-06-01

    Highlights: • Combining laboratory model outputs with operational data. • Isolation of single component from noisy data. • Better understanding of the health of graphite cores. • Extended plant operation through leveraging existing data sources. - Abstract: Installation of new monitoring equipment in Nuclear Power Plants (NPPs) is often difficult and expensive and therefore maximizing the information that can be extracted from existing monitoring equipment is highly desirable. This paper describes the process of combining models derived from laboratory experimentation with current operational plant data to infer an underlying measure of health. A demonstration of this process is provided where the fuel channel bore profile, a measure of core health, is inferred from data gathered during the refuelling process of an Advanced Gas-cooled Reactor (AGR) nuclear power plant core. Laboratory simulation was used to generate a model of an interaction between the fuel assembly and the core. This model is used to isolate a single frictional component from a noisy input signal and use this friction component as a measure of health to assess the current condition of the graphite bricks that comprise the core. In addition, the model is used to generate an expected refuelling response (the noisy input signal) for a given set of channel bore diameter measurements for either insertion of new fuel or removal of spent fuel, providing validation of the model. This benefit of this work is that it provides a greater understanding of the health of the graphite core, which is important for continued and extended operation of the AGR plants in the UK.

  12. First experience in operating the population of the condition database for the CMS experiment

    CERN Document Server

    De Gruttola, M; Futyan, David; Glege, Frank; Govi, Giacomo; Innocente, Vincenzo; Paolucci, Pierluigi; Pierro, Antonio; Schlatter, Dieter

    2010-01-01

    Reliable population of the condition database is critical for the correct operation of the online selection as well as of the offline reconstruction and analysis of data. We will describe here the system put in place in the CMS experiment to populate the database and make condition data promptly available both online for the high-level trigger and offline for reconstruction. The system, designed for high flexibility to cope with very different data sources, uses POOL-ORA technology in order to store data in an object format that best matches the object oriented paradigm for C++ programming language used in the CMS offline software. In order to ensure consistency among the various subdetectors, a dedicated package, PopCon (Populator of Condition Objects), is used to store data online. The data are then automatically streamed to the offline database hence immediately accessible offline worldwide. This mechanism was intensively used during 2008 in the test-runs with cosmic rays. The experience of this first mont...

  13. A hydrodynamic optimization design methodology for a ship bulbous bow under multiple operating conditions

    Directory of Open Access Journals (Sweden)

    Yu Lu

    2016-01-01

    Full Text Available The main objective of this article is to describe an innovative methodology for the hydrodynamic optimization of a ship bulbous bow which considers multiple operating conditions. The proposed method is more practical and effective than the traditional optimization process, which is only based on contractually specified design condition. Parametric form approaches are adopted by employing an F-spline curve in order to generate variants of the hull bulbous bow forms using form design parameters modified, resulting in an optimization system based on improved genetic algorithms. The Rankine source panel method is used for the hydrodynamic evaluation, wherein non-linear free surface conditions and the trim and sinkage of the ship are taken into consideration. The validity and effectiveness of the proposed methodology for a large container ship is investigated by comparing the computational results with experimental data, which demonstrates that the proposed methodology can engage well in the automation process and improve hydrodynamic performance during actual ship design practices.

  14. Operating conditions for the continuous bioremediation of free cyanide contaminated wastewater using Aspergillus awamori.

    Science.gov (United States)

    Santos, B A Q; Ntwampe, S K O; Doughari, J H; Muchatibaya, G

    2014-01-01

    Generation of cyanide-containing wastewater is a growing problem worldwide as numerous cyanide complexes are highly unstable and degrade to form free cyanide (F-CN), the most toxic form of cyanide. Agro-waste materials, such as sweet orange (Citrus sinensis) waste from the citrus industry, are rich in readily metabolisable carbohydrates that can supplement microbial activity and thus support biodegradation of toxic compounds in wastewater. This study reports on optimal operating conditions for the continuous biodegradation of F-CN in wastewater using an Aspergillus awamori isolate in a process supported solely using C. sinensis waste extract. The optimal degradation conditions were pH 8.75 and 37.02 °C with the isolate's F-CN tolerance being observed up to 430 mg F-CN/L. Furthermore, the ammonium produced as a by-product of F-CN degradation was also metabolised by the A. awamori, with negligible residual citric acid and formate being observed in the effluent post treatment. This study demonstrates the feasibility of using agricultural waste as a primary and sole carbon source for the cultivation of a cyanide-degrading A. awamori species for F-CN degradation under alkaline conditions.

  15. OPTIMIZATION OF THE OPERATING CONDITIONS FOR RHAMNOLIPID PRODUCTION USING SLAUGHTERHOUSE-GENERATED INDUSTRIAL FLOAT AS SUBSTRATE

    Directory of Open Access Journals (Sweden)

    W. S. Borges

    2015-06-01

    Full Text Available AbstractBiosurfactants have a wide range of applications in emulsions, separations, and solubilization because these chemicals reduce the surface tension and viscosity of solutions. This work studied rhamnolipid production using a batch bioreactor with a working volume of 1.5 liters, Pseudomonas aeruginosa ATCC (American Type Culture Collection 10145 strain, and the greasy effluent from the slaughter of poultry and pigs as the substrate. The main goal of this research was to evaluate the level of aeration, agitation speed and inoculum concentration using a Central Composite Design (CCD. Experimental conditions were selected using the surface response technique obtained from the CCD, and the results were validated to test the reproducibility. The following operating conditions were selected: 1.2 vvm level of aeration, 600 rpm agitation speed, and 1.0 g/L biomass inoculum concentration. Under these conditions, the following results were obtained: the rhamnose production, surface tension and emulsifying index were 5.37 g/L, 25.6 dyne/cm and 100%, respectively.

  16. Final Report - Advanced MEA's for Enhanced Operating Conditions, Amenable to High Volume Manufacture

    Energy Technology Data Exchange (ETDEWEB)

    Debe, Mark K.

    2007-09-30

    This report summarizes the work completed under a 3M/DOE contract directed at advancing the key fuel cell (FC) components most critical for overcoming the polymer electrolyte membrane fuel cell (PEMFC) performance, durability & cost barriers. This contract focused on the development of advanced ion exchange membranes & electrocatalysts for PEMFCs that will enable operation under ever more demanding automotive operating conditions & the use high volume compatible processes for their manufacture. Higher performing & more durable electrocatalysts must be developed for PEMFCs to meet the power density & lifetime hours required for FC vehicles. At the same time the amount of expensive Pt catalyst must be reduced to lower the MEA costs. While these two properties are met, the catalyst must be made resistant to multiple degradation mechanisms to reach necessary operating lifetimes. In this report, we present the work focused on the development of a completely new approach to PEMFC electrocatalyts, called nanostructured thin film (NSTF) catalysts. The carbon black supports are eliminated with this new approach which eliminates the carbon corrosion issue. The thin film nature of the catalyst significantly improves its robustness against dissolution & grain growth, preserving the surface area. Also, the activity of the NSTF for oxygen reduction is improved by over 500% compared to dispersed Pt catalyts. Finally, the process for fabricating the NSTF catalysts is consistent with high volume roll-good manufacturing & extremely flexible towards the introduction of new catalyst compositions & structures. This report documents the work done to develop new multi-element NSTF catalysts with properties that exceed pure Pt, that are optimized for use with the membranes discussed below, & advance the state-of-the-art towards meeting the DOE 2010 targets for PEMFC electrocatalysts. The work completed advances the understanding of the NSTF catalyst technology, identifies new NSTF

  17. Thermally assisted mechanical dewatering (TAMD) of suspensions of fine particles: analysis of the influence of the operating conditions using the response surface methodology.

    Science.gov (United States)

    Mahmoud, Akrama; Fernandez, Aurora; Chituchi, Toma-Mihai; Arlabosse, Patricia

    2008-08-01

    Thermally assisted mechanical dewatering (TAMD) is a new process for energy-efficient liquid/solids separation which enhances conventional-device efficiency. The main idea of this process is to supply a flow of heat in mechanical dewatering processes to favour the reduction of the liquid content. This is not a new idea but the proposed combination, especially the chosen operating conditions (temperature dewatering parameter and an excellent indicator of the extent of TAMD. In this study, a two-factor central composite rotatable design was used to establish the optimum conditions for the TAMD of suspensions of fine particles. Significant regression models, describing changes on final dry solids content with respect to independent variables, were established with regression coefficients (usually called determination coefficients), R(2), greater than 80%. Experiments were carried out on a laboratory filtration/compression cell, firstly on different compressible materials: synthetic mineral suspensions such as talc and synthetic organic suspensions such as cellulose, and then on industrial materials, such as bentonite sludge provided by Soletanche Bachy Company. Experiment showed that the extent of TAMD for a given material is particularly dependent on their physical and chemical properties but also on processing parameters.

  18. Conditioning of sludge produced through chemical treatment of radioactive liquid waste - Operating experiences

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, D. Anji, E-mail: anji@igcar.gov.i [Centralised Waste Management Facility, Nuclear Recycle Group, BARC Facilities, Kalpakkam 603 102, Tamil Nadu (India); Khandelwal, S.K.; Muthiah, R.; Shanmugamani, A.G.; Paul, Biplob; Rao, S.V.S.; Sinha, P.K. [Centralised Waste Management Facility, Nuclear Recycle Group, BARC Facilities, Kalpakkam 603 102, Tamil Nadu (India)

    2010-07-15

    At Centralised Waste Management Facility (CWMF) 160 m{sup 3} of radioactive chemical sludge, generated from treatment of several batches of category-II and category-III radioactive liquid wastes by chemical precipitation method was stored in clariflocculator (CF) for downstream processing. The sludge needed conditioning before disposal. The analysis of the sludge samples collected at different radial locations and depths from the CF showed suspended solid content of 2.37-13.07% and radioactive content of gross {beta}-{gamma} 5000-27,000 Bq/g and {alpha} 100-600 Bq/g. After comparing different options available for conditioning of the sludge based on their technological and economical aspects, it was decided to dewater it using centrifuge before fixing in cement matrix with additives. Process Control Laboratory of CWMF studied the process in detail to optimize the relevant parameters for fixation of the concentrate obtained from centrifuge. Based on these results, conditioning of the stored sludge was undertaken. The process consisted of diluting the sludge with low active effluents/water for homogenisation and facilitating the transfer of sludge, dewatering of the slurry utilising decanter centrifuge, fixation of dewatered concentrate in Ordinary Portland Cement (OPC) with vermiculite as an additive using in-drum mixing method, providing sufficient time for hardening of fixed mass, transportation and safe disposal into Near Surface Disposal Facility (NSDF). Total 150 m{sup 3} of conditioned waste was produced (750 numbers of drums containing cement fixed concentrate). The paper includes the results of the studies conducted on cement fixed concentrate blocks for finding out their compressive strength and leaching characteristics. It also describes the experiences gained from the above operations.

  19. Optimum Arrangement of Reactive Power Sources While Using Genetic Algori

    Directory of Open Access Journals (Sweden)

    A. M. Hashimov

    2010-01-01

    Full Text Available Reduction of total losses in distribution electricity supply network is considered as an important measure which serves for improvement of efficiency of electric power supply systems. This objective can be achieved by optimum distribution of reactive power sources in proper places of distribution electricity supply network. The proposed methodology is based on application of a genetic algorithm. Total expenses for installation of capacitor banks, their operation and also expenses related to electric power losses are considered as an efficiency function which is used for determination of places with optimum values of capacitor bank power. The methodology is the most efficient for selection of optimum places in the network where it is necessary to install capacitor banks with due account of their power control depending on a switched-on load value in the units.

  20. Optimum climb and descent trajectories for airline missions

    Science.gov (United States)

    Erzberger, H.

    1981-01-01

    The characteristics of optimum fixed-range trajectories whose structure is constrained to climb, steady cruise, and descent segments are derived by application of optimal control theory. The performance function consists of the sum of fuel and time costs, referred to as direct operating cost (DOC). The state variable is range to go and the independent variable is energy. In this formulation a cruise segment always occurs at the optimum cruise energy for sufficiently large range. At short ranges (400 n. mi. and less), a cruise segment may also occur below the optimum cruise energy. The existence of such a cruise segment depends primarily on the fuel flow vs thrust characteristics and on thrust constraints. If thrust is a free control variable along with airspeed, it is shown that such cruise segments will not generally occur. If thrust is constrained to some maximum value in climb and to some minimum in descent, such cruise segments generally will occur.

  1. Wind tunnel testing of the DeepWind demonstrator in design and tilted operating conditions

    DEFF Research Database (Denmark)

    Battistia, L.; Benini, E.; Brighenti, A.

    2016-01-01

    ) configuration. The velocity field in the wake of the rotor was also fully characterized by means of an instrumented traversing system, to investigate the flow distribution downstream of the test section. Special care is taken in the description of the experimental set-up and of the measured data, so......The DeepWind Project aims at investigating the feasibility of a new floating vertical-axis wind turbine (VAWT) concept, whose purpose is to exploit wind resources at deep-water offshore sites. The results of an extensive experimental campaign on the DeepWind reduced scale demonstrator are here...... was installed on a high precision test bench, whose axis was suitable to be inclined up to 15° with respect to the design (i.e. upright) operating condition. The experiments were performed at the large scale, high speed wind tunnel of the Politecnico di Milano (Italy), using a “free jet” (open channel...

  2. Reverse osmosis filtration for space mission wastewater: membrane properties and operating conditions

    Science.gov (United States)

    Lee, S.; Lueptow, R. M.

    2001-01-01

    Reverse osmosis (RO) is a compact process that has potential for the removal of ionic and organic pollutants for recycling space mission wastewater. Seven candidate RO membranes were compared using a batch stirred cell to determine the membrane flux and the solute rejection for synthetic space mission wastewaters. Even though the urea molecule is larger than ions such as Na+, Cl-, and NH4+, the rejection of urea is lower. This indicates that the chemical interaction between solutes and the membrane is more important than the size exclusion effect. Low pressure reverse osmosis (LPRO) membranes appear to be most desirable because of their high permeate flux and rejection. Solute rejection is dependent on the shear rate, indicating the importance of concentration polarization. A simple transport model based on the solution-diffusion model incorporating concentration polarization is used to interpret the experimental results and predict rejection over a range of operating conditions. Grant numbers: NAG 9-1053.

  3. A Review & Assessment of Current Operating Conditions Allowable Stresses in ASME Section III Subsection NH

    Energy Technology Data Exchange (ETDEWEB)

    R. W. Swindeman

    2009-12-14

    The current operating condition allowable stresses provided in ASME Section III, Subsection NH were reviewed for consistency with the criteria used to establish the stress allowables and with the allowable stresses provided in ASME Section II, Part D. It was found that the S{sub o} values in ASME III-NH were consistent with the S values in ASME IID for the five materials of interest. However, it was found that 0.80 S{sub r} was less than S{sub o} for some temperatures for four of the materials. Only values for alloy 800H appeared to be consistent with the criteria on which S{sub o} values are established. With the intent of undertaking a more detailed evaluation of issues related to the allowable stresses in ASME III-NH, the availabilities of databases for the five materials were reviewed and augmented databases were assembled.

  4. Reverse osmosis filtration for space mission wastewater: membrane properties and operating conditions

    Science.gov (United States)

    Lee, S.; Lueptow, R. M.

    2001-01-01

    Reverse osmosis (RO) is a compact process that has potential for the removal of ionic and organic pollutants for recycling space mission wastewater. Seven candidate RO membranes were compared using a batch stirred cell to determine the membrane flux and the solute rejection for synthetic space mission wastewaters. Even though the urea molecule is larger than ions such as Na+, Cl-, and NH4+, the rejection of urea is lower. This indicates that the chemical interaction between solutes and the membrane is more important than the size exclusion effect. Low pressure reverse osmosis (LPRO) membranes appear to be most desirable because of their high permeate flux and rejection. Solute rejection is dependent on the shear rate, indicating the importance of concentration polarization. A simple transport model based on the solution-diffusion model incorporating concentration polarization is used to interpret the experimental results and predict rejection over a range of operating conditions. Grant numbers: NAG 9-1053.

  5. RANS simulation of cavitation and hull pressure fluctuation for marine propeller operating behind-hull condition

    Directory of Open Access Journals (Sweden)

    Kwang-Jun Paik

    2013-12-01

    Full Text Available Simulations of cavitation flow and hull pressure fluctuation for a marine propeller operating behind a hull using the unsteady Reynolds-Averaged Navier-Stokes equations (RANS are presented. A full hull body submerged under the free surface is modeled in the computational domain to simulate directly the wake field of the ship at the propeller plane. Simulations are performed in design and ballast draught conditions to study the effect of cavitation number. And two propellers with slightly different geometry are simulated to validate the detectability of the numerical simulation. All simulations are performed using a commercial CFD software FLUENT. Cavitation patterns of the simulations show good agreement with the experimental results carried out in Samsung CAvitation Tunnel (SCAT. The simulation results for the hull pressure fluctuation induced by a propeller are also compared with the experimental results showing good agreement in the tendency and amplitude, especially, for the first blade frequency.

  6. Characterization of hot-gas filter ash under PFBC operating conditions

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, A.K.; Swanson, M.L.; Hurley, J.P.; Watne, E.M. [Univ. of North Dakota, Grand Forks, ND (United States). Energy and Environmental Research Center

    1997-12-31

    The objective of this program was to perform bench-scale dynamic tests of ash formation and long-term ash cake formation in pressurized fluidized-bed combustion (PFBC) systems to help in the development of methods to predict possible filter bridging problems and suggest possible strategies for mitigating these problems. During the program, four ash formation tests using a washed coal from the Consol Enlow Fork mine, with two size distributions of Plum Run dolomite at two different temperatures, were completed under conditions simulating the operation of the American Electric Power (AEP) Tidd PFBC. In addition, the same test matrix, plus two tests using no sorbent, was completed with the Belle Ayr Powder River Basin subbituminous coal, which will be used at the Southern Company Services (SCS) Wilsonville, Alabama, power systems development facility (PSDF).

  7. Characterization of hot-gas filter ash under PFBC operating conditions

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, A.K.; Swanson, M.L.; Hurley, J.P.; Watne, T.M.

    1998-01-01

    The objective of this program was to perform bench scale dynamic tests of ash formation and long-term ash cake formation in pressurized fluidized bed combustion (PFBC) systems to help in the development of methods to predict possible filter bridging problems and suggest possible strategies for mitigating these problems. During the program, four ash formation tests using a washed coal from the Consol Enlow Fork mine, with two size distributions of Plum Run dolomite at two different temperatures, were completed under conditions simulating the operation of the American Electric Power (AEP) Tidd PFBC. In addition, the same test matrix, plus two tests using no sorbent, was completed with the Belle Ayr Powder River Basin sub-bituminous coal, which will be used at the Southern Company Services (SCS) Wilsonville, Alabama, power systems development facility (PSDF).

  8. Reaction Mechanism of Thiophene on Vanadium Oxides under FCC Operating Conditions

    Institute of Scientific and Technical Information of China (English)

    Wang Peng; Zheng Aiguo; Tian Huiping; Long Jun

    2004-01-01

    The reaction mechanism of thiophene on vanadium oxides under FCC operating conditions had been preliminary studied using in-situ FT-IR analysis of thiophene and atmospheric pressure continuous fixed-bed reaction, followed by characterization via pyridine adsorption-temperature programmed desorption method, and FT-IR and XPS spectra. The research had discovered that, under 500C thiophene could undergo the redox reaction with V2O5, while being converted into CO, CO2 as well as SO2 with its conversion rate reaching 41.2%. At the same time the oxidation number of vanadium decreased. The existence of a few Bronsted acid centers on V2O5 could lead to an increase of H2S yield among the products derived from the reaction with thiophene.

  9. Study and Development of an Air Conditioning System Operating on a Magnetic Heat Pump Cycle

    Science.gov (United States)

    Wang, Pao-Lien

    1991-01-01

    This report describes the design of a laboratory scale demonstration prototype of an air conditioning system operating on a magnetic heat pump cycle. Design parameters were selected through studies performed by a Kennedy Space Center (KSC) System Simulation Computer Model. The heat pump consists of a rotor turning through four magnetic fields that are created by permanent magnets. Gadolinium was selected as the working material for this demonstration prototype. The rotor was designed to be constructed of flat parallel disks of gadolinium with very little space in between. The rotor rotates in an aluminum housing. The laboratory scale demonstration prototype is designed to provide a theoretical Carnot Cycle efficiency of 62 percent and a Coefficient of Performance of 16.55.

  10. Physiotherapy-provided operant conditioning in the management of low back pain disability: A systematic review.

    Science.gov (United States)

    Bunzli, Samantha; Gillham, David; Esterman, Adrian

    2011-03-01

     Non-specific low back pain (LBP) is a leading cause of disability in developed countries. Behavioural interventions have been found efficacious in reducing disability in LBP. Operant conditioning is one type of behavioural intervention being employed by physiotherapists; however, the effectiveness of physiotherapist-provided operant conditioning (POC) in the management of LBP disability is unknown. This review aims to answer the question: is POC more effective than comparison interventions in reducing LBP disability?   A systematic review of randomized controlled trials was conducted using a qualitative analysis of effect. Participants were adults ≥18 years with non-specific LBP. The intervention was defined as a time contingent, graduated increase in activity including goal setting and the education and reinforcement of positive pain behaviours with the aim of decreasing disability. The primary outcome measure was back pain specific disability. Secondary outcomes included generic functional status, pain intensity, sick leave, fear avoidance beliefs or behaviour and adverse effects.   Fifteen trials involving 3737 people were included. Eight studies reported a clinically significant difference. The POC intervention was not found to be inferior to any of the comparison interventions in reducing disability. Moderate evidence was found that POC is more effective than other behavioural interventions in reducing long term disability in chronic LBP. Moderate evidence showed POC may be more effective than other treatments in reducing post-treatment fear avoidance beliefs in a sub-acute population but less effective in reducing short term fear avoidance beliefs in a population with mixed LBP. Moderate evidence showed POC is more effective than a placebo intervention in reducing short term pain in sub-acute LBP.   POC may be considered efficacious in the treatment of LBP. Physiotherapists may also consider POC for its additional effect of reducing long term

  11. Influence of the operating conditions on highly oxidative radicals generation in Fenton's systems.

    Science.gov (United States)

    Ciotti, Cesare; Baciocchi, Renato; Tuhkanen, Tuula

    2009-01-15

    In this work, an indirect method for estimating the total amount and concentration of oxidative radicals in aqueous and slurry-phase Fenton's systems was developed. This method, based on the use of benzoic acid as probe compound, was applied for evaluating the effect of the operating conditions on the radicals amount produced, their production efficiency (i.e. moles of radicals generated per mole H2O2 and their concentration. A Rotatable Central Composite design (RCC) was used to select the operating conditions in order to get a statistically meaningful data set. Hydrogen peroxide and ferrous ion concentrations ranged between 0.2-1mM and 0.2-0.5mM, respectively; humic acid concentration between 0 and 15mg/L, whereas the soil/water weight ratio in slurry-phase systems between 1:10 and 9:10. The probe compound concentration was 9 or 0.1mM in experiments aimed to evaluate the total amount or concentration of oxidative radicals, respectively. The obtained results indicated that the amount of radicals generated in both aqueous and soil slurry Fenton's system increased with higher H2O2 concentration and, more specifically, that their production efficiency increased with increasing Fe(II):H2O2 molar ratio. Addition of dissolved organic compounds as humic acid did not notably affect the oxidative radicals amount and concentration. On the contrary, a one order of magnitude reduction in both radicals amount generated and concentration was observed when soil was added to the reaction environment.

  12. Two simple multivariate procedures for monitoring planetary gearboxes in non-stationary operating conditions

    Science.gov (United States)

    Zimroz, Radoslaw; Bartkowiak, Anna

    2013-07-01

    This paper deals with the diagnostics of planetary gearboxes under nonstationary operating conditions. In most diagnostics applications, energy of vibration signals (calculated directly from time series or extracted from spectral representation of signal) is used. Unfortunately energy based features are sensitive to load conditions and it makes diagnostics difficult. In this paper we used energy based 15D data vectors (namely spectral amplitudes of planetary mesh frequency and its harmonics) in order to investigate if it is possible to improve diagnostics efficiency in comparison to previous, one dimensional, approaches proposed for the same problem. Two multivariate methods, Principal Component Analysis (PCA) and Canonical Discriminant Analysis (CDA), were used as techniques for data analysis. We used these techniques in order to investigate dimensionality of the data and to visualize data in 3D and 2D spaces in order to understand data behavior and assess classification ability. As a case study the data from two planetary gearboxes used in complex mining machines (one in bad condition and the other in good condition) were analyzed. For these two machines more than 2000 15D vectors were acquired. It should be noted that due to non-stationarity of loading conditions, previous diagnostics results obtained using other techniques were moderately good (ca. 80% recognition efficiency); however there is still some need to improve diagnostics classification ability. After application of the proposed approaches it was found that the entire data could be reduced to 2 dimensions whereby data instances became visible and a good discriminant function (characterized by a misclassification rate of .0023, i.e. only 5 erroneous classifications for a total of 2183 instances) could be derived. This paper suggests a novel way for condition monitoring of planetary gearboxes based on multivariate statistics. The emphasis is put on the algebraic and geometric interpretations of the PCA

  13. Mercury-Cadmium-Telluride Focal Plane Array Performance Under Non-Standard Operating Conditions

    Science.gov (United States)

    Richardson, Brandon S.; Eastwood, Michael L.; Bruce, Carl F.; Green, Robert O.; Coles, J. B.

    2011-01-01

    This paper highlights a new technique that allows the Teledyne Scientific & Imaging LLC TCM6604A Mercury-Cadmium-Telluride (MCT) Focal Plane Array (FPA) to operate at room temperature. The Teledyne MCT FPA has been a standard in Imaging Spectroscopy since its creation in the 1980's. This FPA has been used in applications ranging from space instruments such as CRISM, M3 and ARTEMIS to airborne instruments such as MaRS and the Next Generation AVIRIS Instruments1. Precise focal plane alignment is always a challenge for such instruments. The current FPA alignment process results in multiple cold cycles requiring week-long durations, thereby increasing the risk and cost of a project. These alignment cycles are necessary because optimal alignment is approached incrementally and can only be measured with the FPA and Optics at standard operating conditions, requiring a cold instrument. Instruments using this FPA are normally cooled to temperatures below 150K for the MCT FPA to properly function. When the FPA is run at higher temperatures the dark current increases saturating the output. This paper covers the prospect of warm MCT FPA operation from a theoretical and experimental perspective. We discuss the empirical models and physical laws that govern MCT material properties and predict the optimal settings that will result in the best MCT PA performance at 300K. Theoretical results are then calculated for the proposed settings. We finally present the images and data obtained using the actual system with the warm MCT FPA settings. The paper concludes by emphasizing the strong positive correlation between the measured values and the theoretical results.

  14. Mercury-Cadmium-Telluride Focal Plane Array Performance Under Non-Standard Operating Conditions

    Science.gov (United States)

    Richardson, Brandon S.; Eastwood, Michael L.; Bruce, Carl F.; Green, Robert O.; Coles, J. B.

    2011-01-01

    This paper highlights a new technique that allows the Teledyne Scientific & Imaging LLC TCM6604A Mercury-Cadmium-Telluride (MCT) Focal Plane Array (FPA) to operate at room temperature. The Teledyne MCT FPA has been a standard in Imaging Spectroscopy since its creation in the 1980's. This FPA has been used in applications ranging from space instruments such as CRISM, M3 and ARTEMIS to airborne instruments such as MaRS and the Next Generation AVIRIS Instruments1. Precise focal plane alignment is always a challenge for such instruments. The current FPA alignment process results in multiple cold cycles requiring week-long durations, thereby increasing the risk and cost of a project. These alignment cycles are necessary because optimal alignment is approached incrementally and can only be measured with the FPA and Optics at standard operating conditions, requiring a cold instrument. Instruments using this FPA are normally cooled to temperatures below 150K for the MCT FPA to properly function. When the FPA is run at higher temperatures the dark current increases saturating the output. This paper covers the prospect of warm MCT FPA operation from a theoretical and experimental perspective. We discuss the empirical models and physical laws that govern MCT material properties and predict the optimal settings that will result in the best MCT PA performance at 300K. Theoretical results are then calculated for the proposed settings. We finally present the images and data obtained using the actual system with the warm MCT FPA settings. The paper concludes by emphasizing the strong positive correlation between the measured values and the theoretical results.

  15. Aeroacoustic Simulation for NASA CC3 Centrifugal Compressor Operating at off Design Condition

    Directory of Open Access Journals (Sweden)

    Alqaradawi Mohamed

    2016-01-01

    Full Text Available This paper covers the characterization of the acoustic noise and the unsteady flow field of a high speed centrifugal compressor NASA CC3. In order to accurately predict the noise, all analyses are carried out through the use of Large Eddy Simulation and Ffowcs Williams–Hawkings model for noise prediction. The relative effect of hub cavity on flow characteristics and sound levels is investigated, for a compressor stage with a total pressure ratio equal to 4, working from surge to near choke condition. In comparison with the experimental results from literature, the predicted compressor performance and flow field are predicted well. The hub cavity flow effect on the compressor aeroacoustic generated noise is shown in the paper. The unsteady static pressure and sound pressure levels are compared not only at different location but also for design and off design operating points. The internal flow results inside the hub cavity are presented at surge, design and near choke points. The conclusion is that the cavity effect of the centrifugal compressor cannot be ignored in the numerical prediction of aerodynamic generated noise. The impeller back plate of the rotor experiences a strong pressure fluctuation, which is maxima at the impeller outer radius for all operating point, but higher pressure values at the surge point.

  16. Cross spectral energy method for damage assessment of the cable-stayed bridge under operational conditions

    Institute of Scientific and Technical Information of China (English)

    Yang Hezhen; Li Huajun

    2008-01-01

    The new cross spectral energy method (CSEM) is proposed for maintaining cable-stayed bridge safety by the measurable output-only vibration response.Damage assessment of real structures is limited by a series of problems such as unknown ambient excitation forces, errors introduced by system identification,incomplete dynamic measurements, etc.Thus the methodology based on cross spectral energy of each substructure member is derived to meet these challenges.The novel damage index does not require any modal or parameter identification technology.It can be calculated directly from vibration test data.In order to evaluate the efficiency of the presented methodology, a three dimensional (3D) actual cable-stayed bridge model with one or more damaged positions under operational conditions was studied.In order to testify the reliability of damage detection method, the response data was polluted by the random noise.It is proved that the proposed method can successfully localize all damage cases even in noisy data.With the help of examples, the CSEM can potentially be applied as a nondestructive evaluation technique (NDT) for on-line health monitoring of cable-stayed bridges with minimum disruption of its operations.

  17. [Air conditioning units and warm air blankets in the operating room].

    Science.gov (United States)

    Kerwat, Klaus; Piechowiak, Karolin; Wulf, Hinnerk

    2013-01-01

    Nowadays almost all operating rooms are equipped with air conditioning (AC units). Their main purpose is climatization, like ventilation, moisturizing, cooling and also the warming of the room in large buildings. In operating rooms they have an additional function in the prevention of infections, especially the avoidance of postoperative wound infections. This is achieved by special filtration systems and by the creation of specific air currents. Since hypothermia is known to be an unambiguous factor for the development of postoperative wound infections, patients are often actively warmed intraoperatively using warm air blankets (forced-air warming units). In such cases it is frequently discussed whether such warm air blankets affect the performance of AC units by changing the air currents or whether, in contrast, have exactly the opposite effect. However, it has been demonstrated in numerous studies that warm air blankets do not have any relevant effect on the functioning of AC units. Also there are no indications that their use increases the rate of postoperative wound infections. By preventing the patient from experiencing hypothermia, the rate of postoperative wound infections can even be decreased thereby. © Georg Thieme Verlag Stuttgart · New York.

  18. Effect of activated sludge properties and membrane operation conditions on fouling characteristics in membrane bioreactors.

    Science.gov (United States)

    Choi, Hyeok; Zhang, Kai; Dionysiou, Dionysios D; Oerther, Daniel B; Sorial, George A

    2006-06-01

    Biofouling control is considered to be a major challenge in operating membrane bioreactors (MBRs) for the treatment of wastewater. This study examined the impact of biological, chemical, and physical properties of activated sludge on membrane filtration performance in laboratory-scale MBRs. Sludges with different microbial communities were produced using pseudo-continuous stirred-tank reactors and pseudo-plug flow reactors treating a synthetic paper mill wastewater. Various filtration resistances were used to investigate membrane fouling characteristics, and molecular biology tools targeting 16S ribosomal DNA gene sequences were used to identify predominant bacterial populations in the sludges or attached to the fouled membranes. Filtration experiments using axenic cultures of Escherichia coli, Acinetobacter calcoaceticus, and Gordonia amarae were also performed to better understand the initiation and development of biofouling. The results showed that the tendency of membranes to biofoul depended upon membrane operating conditions as well as the properties of the activated sludge in the MBR systems. Specific bacterial populations, which were not dominant in the activated sludges, were selectively accumulated on the membrane surface leading to the development of irreversible biofouling.

  19. Contaminant removal in septage treatment with vertical flow constructed wetlands operated under batch flow conditions.

    Science.gov (United States)

    Jong, Valerie Siaw Wee; Tang, Fu Ee

    2016-01-01

    Individual septic tanks are the most common means of on-site sanitation in Malaysia, but they result in a significant volume of septage. A two-staged vertical flow constructed wetlands (VFCWs) system for the treatment of septage was constructed and studied in Sarawak, Malaysia. Raw septage was treated in the first stage wetlands, and the resulting percolate was fed onto the second stage wetlands for further treatment. Here, the effects of a batch loading regime on the contaminant removal efficiency at the second stage wetlands, which included palm kernel shell within their filter substrate, are presented. The batch loading regime with pond:rest (P:R) period of 1:1, 2:2 and 3:3 (day:day) was studied. The improvement of the effluent redox condition was evident with P:R = 3:3, resulting in excellent organic matters (chemical oxygen demand and biochemical oxygen demand) and nitrogen reduction. The bed operated with P:R = 1:1 experienced constant clogging, with a water layer observed on the bed surface. For the P:R = 3:3 regime, the dissolved oxygen profile was not found to decay drastically after 24 hours of ponding, suggesting that the biodegradation mainly occurred during the first day. The study results indicate that a suitable application regime with an adequate rest period is important in VFCWs to ensure efficient operation.

  20. Unsteady Pressure Measurements around Rotor of an Axial Flow Fan under Stable and Unstable Operating Conditions

    Science.gov (United States)

    Shin, You Hwan; Kim, Kwang Ho; Kang, Chang Sik

    This study presents some measurement results on the unsteady pressure fields around rotor under stable and unstable operating conditions of an axial flow fan. The unsteady static pressure of rotor passage was measured by using high frequency pressure transducers mounted on the casing wall. The measurements on the unsteady total pressure at rotor inlet and outlet were also conducted with specially designed high frequency total pressure probe. Double Phase-Locked Ensemble Averaging Technique was used for analysis of pressure fluctuations around the rotor at rotating stall onset point. From the results, the unsteady pressure fields during stable and unstable operations of the axial fan were investigated and compared with each other. Particularly one period of rotating stall could be divided into two regions, stalled flow and unstalled flow region respectively. Furthermore the former could be also classified into two zones, bubbled and disturbed region by their features. The flow characteristics for each zone were described in detail and the static and total pressure fields were also analyzed in terms of the pressure distribution along pressure side and suction side on the blade tip profile.

  1. Main mechanisms of material properties degradation under reactor pressure vessel operating conditions

    Energy Technology Data Exchange (ETDEWEB)

    Karzov, Georgy; Timofeev, Boris [Central Research Inst. of Structural Materials ' prometey' , St. Petersburg (Russian Federation)

    1999-07-01

    In the process of NPP equipment operation materials are subjected to a prolonged influence of loads, associated with the variation of inner pressure and temperature under various conditions. Each equipment element damage is associated with some material fracture mechanism. For NPP equipment the mechanisms of irreversible damage accumulation are related with: irradiation embrittlement, thermal and strain aging, fatigue damages from mechanical and thermal loading, stress corrosion and fatigue corrosion, creep and thermal relaxation stresses, erosion and weak, thermal shock. The basic tasks of specialists working in the sphere of the provision of reliability and service life of nuclear power equipment are not only the determination of the main mechanisms of damages and reasons of their appearance, but also the study of methods which would permit to control these properties completely. By giving some examples of Russian NPP equipment with VVER-440 and VVER-1000 reactors the paper presents most typical degradation mechanisms of equipment material properties, including weldments, in the process of operation and methods to recover by using various technological means. (author)

  2. Flexible operation strategy for environment control system in abnormal supply power condition

    Science.gov (United States)

    Liping, Pang; Guoxiang, Li; Hongquan, Qu; Yufeng, Fang

    2017-04-01

    This paper establishes an optimization method that can be applied to the flexible operation of the environment control system in an abnormal supply power condition. A proposed conception of lifespan is used to evaluate the depletion time of the non-regenerative substance. The optimization objective function is to maximize the lifespans. The optimization variables are the allocated powers of subsystems. The improved Non-dominated Sorting Genetic Algorithm is adopted to obtain the pareto optimization frontier with the constraints of the cabin environmental parameters and the adjustable operating parameters of the subsystems. Based on the same importance of objective functions, the preferred power allocation of subsystems can be optimized. Then the corresponding running parameters of subsystems can be determined to ensure the maximum lifespans. A long-duration space station with three astronauts is used to show the implementation of the proposed optimization method. Three different CO2 partial pressure levels are taken into consideration in this study. The optimization results show that the proposed optimization method can obtain the preferred power allocation for the subsystems when the supply power is at a less-than-nominal value. The method can be applied to the autonomous control for the emergency response of the environment control system.

  3. 76 FR 66660 - Special Conditions: Gulfstream Aerospace LP (GALP) Model G280 Airplane, Operation Without Normal...

    Science.gov (United States)

    2011-10-27

    ... G280 Airplane, Operation Without Normal Electrical Power AGENCY: Federal Aviation Administration (FAA... design feature associated with operation without normal electrical power. The applicable airworthiness... have a novel or unusual design feature associated with operation without normal electrical power....

  4. 78 FR 73112 - Monitoring System Conditions-Transmission Operations Reliability Standards; Interconnection...

    Science.gov (United States)

    2013-12-05

    ..., performance, and maintenance of real-time monitoring and analysis capabilities for reliability coordinators... Reliability Standards; Interconnection Reliability Operations and Coordination Reliability Standards AGENCY... Transmission Operations and Interconnection Reliability Operations and Coordination Reliability Standards...

  5. Assessment of biogas production from MBT waste under different operating conditions

    DEFF Research Database (Denmark)

    Pantini, Sara; Verginelli, Jason; Lombardi, Francesco

    2015-01-01

    In this work, the influence of different operating conditions on the biogas production from mechanically-. biologically treated (MBT) wastes is investigated. Specifically, different lab-scale anaerobic tests varying the water content (26-43% w/w up to 75% w/w), the temperature (from 20 to 25...... degrees C up to 55 degrees C) and the amount of inoculum have been performed on waste samples collected from a full-scale Italian MBT plant. For each test, the gas generation yield and, where applicable, the first-order gas generation rates were determined. Nearly all tests were characterised by a quite...... to deplete the MBT waste gas generation capacity were observed. At these test conditions, the effect of temperature became evident, leading to gas generation rates of 0.007 d(-1) at room temperature that increased to 0.03-0.05 d(-1) at 37 degrees C and to 0.04-0.11 d(-1) at 55 degrees C. Overall...

  6. Operational data and thermodynamic modeling of a Stirling-dish demonstration installation in desert conditions

    Science.gov (United States)

    Nilsson, Martin; Jamot, Jakob; Malm, Tommy

    2017-06-01

    To field test its Stirling-dish unit, Cleanergy AB of Sweden in Q1 2015 built a ten unit demo park in Dubai. The first STE (Solar Thermal Energy) generation of its Stirling genset, the C11S, had at its core an 11 kWel Stirling engine/generator combination. The genset was mated with a parabolic concentrator developed for the genset by a supplier. Local weather conditions in Dubai provide opportunities to test performance in an environment with high insolation and high ambient temperature. In addition, the conditions in Dubai are windy, salty, humid and dusty, historically challenging for solar technologies [1]. In Q1 2016 one of the C11S Stirling-dish units was replaced by the first prototype of Cleanergy's second generation Stirling genset, the Sunbox, and an in-house developed parabolic concentrator. Operational data from field testing during the spring of 2016 are presented and discussed and show the large performance improvement achieved with the Sunbox unit.

  7. Optimizing operating conditions and electrochemical characterization of glucose-gluconate alkaline fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Pasta, M. [Universita degli Studi di Milano, Dipartimento di Chimica Inorganica, Metallorganica e Analitica ' ' Lamberto Malatesta' ' , Via Venezian 21, 20133 Milano (Italy); Department of Material Science and Engineering, Stanford University, Stanford, CA 94305 (United States); La Mantia, F. [Department of Material Science and Engineering, Stanford University, Stanford, CA 94305 (United States); Ruffo, R.; Mari, C.M. [Universita degli Studi di Milano-Bicocca, Dipartmento di Scienza dei Materiali, Via Cozzi 53, 20125 Milano (Italy); Peri, F. [Universita degli Studi di Milano-Bicocca, Dipartimento di Biotecnologia e Bioscienze, P.zza della Scienza 2, 20126 Milano (Italy); Pina, C. Della [Universita degli Studi di Milano, Dipartimento di Chimica Inorganica, Metallorganica e Analitica ' ' Lamberto Malatesta' ' , Via Venezian 21, 20133 Milano (Italy)

    2011-02-01

    The direct oxidation of glucose to produce electrical energy has been widely investigated because of renewability, abundance, high energy density and easy handling of the carbohydrate. Most of the previous studies have been conducted in extreme conditions in order to achieve complete glucose oxidation to CO{sub 2}, neglecting the carbohydrate chemical instability that generally leads to useless by-products mixtures. The partial oxidation to gluconate, originally studied for implantable fuel cells, has the advantage of generating a commercially valuable chemical. In the present paper we optimized fuel composition and operating conditions in order to selectively oxidize glucose to gluconate, maximizing the power density output of a standard commercial platinum based anode material. A deep electrochemical characterization concerning reversible potential, cyclic voltammetry and overpotential measurements have been carried out at 25 C in the D-(+)-glucose concentration range 1.0 x 10{sup -2} to 1.0 M. NMR and EIS investigation clarify the role of the buffer in enhancing the electrochemical performance. (author)

  8. A diagnostic signal selection scheme for planetary gearbox vibration monitoring under non-stationary operational conditions

    Science.gov (United States)

    Feng, Ke; Wang, KeSheng; Zhang, Mian; Ni, Qing; Zuo, Ming J.

    2017-03-01

    The planetary gearbox, due to its unique mechanical structures, is an important rotating machine for transmission systems. Its engineering applications are often in non-stationary operational conditions, such as helicopters, wind energy systems, etc. The unique physical structures and working conditions make the vibrations measured from planetary gearboxes exhibit a complex time-varying modulation and therefore yield complicated spectral structures. As a result, traditional signal processing methods, such as Fourier analysis, and the selection of characteristic fault frequencies for diagnosis face serious challenges. To overcome this drawback, this paper proposes a signal selection scheme for fault-emphasized diagnostics based upon two order tracking techniques. The basic procedures for the proposed scheme are as follows. (1) Computed order tracking is applied to reveal the order contents and identify the order(s) of interest. (2) Vold-Kalman filter order tracking is used to extract the order(s) of interest—these filtered order(s) constitute the so-called selected vibrations. (3) Time domain statistic indicators are applied to the selected vibrations for faulty information-emphasized diagnostics. The proposed scheme is explained and demonstrated in a signal simulation model and experimental studies and the method proves to be effective for planetary gearbox fault diagnosis.

  9. Gas chromatographic quantitative analysis of methanol in wine: operative conditions, optimization and calibration model choice.

    Science.gov (United States)

    Caruso, Rosario; Gambino, Grazia Laura; Scordino, Monica; Sabatino, Leonardo; Traulo, Pasqualino; Gagliano, Giacomo

    2011-12-01

    The influence of the wine distillation process on methanol content has been determined by quantitative analysis using gas chromatographic flame ionization (GC-FID) detection. A comparative study between direct injection of diluted wine and injection of distilled wine was performed. The distillation process does not affect methanol quantification in wines in proportions higher than 10%. While quantification performed on distilled samples gives more reliable results, a screening method for wine injection after a 1:5 water dilution could be employed. The proposed technique was found to be a compromise between the time consuming distillation process and direct wine injection. In the studied calibration range, the stability of the volatile compounds in the reference solution is concentration-dependent. The stability is higher in the less concentrated reference solution. To shorten the operation time, a stronger temperature ramp and carrier flow rate was employed. With these conditions, helium consumption and column thermal stress were increased. However, detection limits, calibration limits, and analytical method performances are not affected substantially by changing from normal to forced GC conditions. Statistical data evaluation were made using both ordinary (OLS) and bivariate least squares (BLS) calibration models. Further confirmation was obtained that limit of detection (LOD) values, calculated according to the 3sigma approach, are lower than the respective Hubaux-Vos (H-V) calculation method. H-V LOD depends upon background noise, calibration parameters and the number of reference standard solutions employed in producing the calibration curve. These remarks are confirmed by both calibration models used.

  10. Acetylcholine release in the hippocampus during the operant conditioned reflex and the footshock stimulus in rats.

    Science.gov (United States)

    Dong, Yu; Mao, Jianjun; Shangguan, Dihua; Zhao, Rui; Liu, Guoquan

    2004-10-14

    The activity of the septo-hippocampal cholinergic pathway was investigated by measuring changes in the extracellular acetylcholine (ACh) levels in the hippocampus, by means of microdialysis, during the operant conditioned reflex and the repeated footshock stimulus. Microdialysis samplings were conducted in a Skinner box where lights were delivered as conditioned stimuli (CS) paired with footshocks as unconditioned stimuli (US). Two groups of rats were used. Extracellular ACh and choline (Ch) in samples collected at 6min intervals were assessed by high-performance liquid chromatography with electrochemical detection. The elevation of hippocampus ACh was observed in the two experimental groups. The increase in ACh during aversive stimulus (footshock) was significantly larger and was probably related to the number of footshocks. There might be moderate increase in the hippocampal ACh release during the retrieval of information. The concentration of choline showed no significant fluctuation in the two groups during the whole process. This experiment explored in more detail hippocampal cholinergic activity in relation to the two different procedures.

  11. Influence of operational conditions on biofilm specific activity of an anaerobic fluidized bed reactor.

    Science.gov (United States)

    García-Morales, J L; Romero, L I; Sales, D

    2003-01-01

    A key parameter in water and wastewater treatment technology is the biomass activity in terms of substrate removal ability. The effects of organic load rate and percentage of bed expansion on biofilm specific methanogenic activity were determined in an anaerobic fluidized bed reactor treating wine-distillery wastes in the thermophilic range (55 degrees C). The proposed activity tests are highly reproducible: an experiment with three identical tests has shown that the standard deviation with respect to the mean values is less than 3%. Specific tests are applied to measure the maximum methanogenic activities of the biomass carrier in lab-scale anaerobic biofilm reactors. These tests have been successfully applied for monitoring the support colonization process and the evolution of biofilm activity in reactors, anaerobic filter and fluidized bed, with different operating conditions. The results show a dependence between the percentage of bed expansion and the specific activity of methanogenic microbiote on biofilm. There is a relationship between the percentage of bed expansion, the sheer stress on the biofilm and the hydrodynamic conditions in the system. Initial biofilm detachment can be compensated with the increase of biomass and of its activity due to the reduction of the substrate diffusional limitations to the microorganism growth inside the support pores.

  12. OPERANT CONDITIONING OF SPINAL REFLEXES:FROM BASIC SCIENCE TO CLINICAL THERAPY

    Directory of Open Access Journals (Sweden)

    Aiko K. Thompson

    2014-03-01

    Full Text Available New appreciation of the adaptive capabilities of the nervous system, recent recognition that most spinal cord injuries are incomplete, and progress in enabling regeneration are generating growing interest in novel rehabilitation therapies. Here we review the 35-year evolution of one promising new approach, operant conditioning of spinal reflexes. This work began in the late 1970’s as basic science; its purpose was to develop and exploit a uniquely accessible model for studying the acquisition and maintenance of a simple behavior in the mammalian CNS. The model was developed first in monkeys and then in rats, mice, and humans. Studies with it showed that the ostensibly simple behavior (i.e., a larger or smaller reflex rests on a complex hierarchy of brain and spinal cord plasticity; and current investigations are delineating this plasticity and its interactions with the plasticity that supports other behaviors. In the last decade, the possible therapeutic uses of reflex conditioning have come under study, first in rats and then in humans. The initial results are very exciting, and they are spurring further studies. At the same time, the original basic science purpose and the new clinical purpose are enabling and illuminating each other in unexpected ways. The long course and current state of this work illustrate the practical importance of basic research and the valuable synergy that can develop between basic science questions and clinical needs.

  13. Tribological Evaluation of Candidate Gear Materials Operating Under Light Loads in Highly Humid Conditions

    Science.gov (United States)

    Dellacorte, Christopher; Thomas, Fransua; Leak, Olivia Ann

    2015-01-01

    A series of pin-on-disk sliding wear tests were undertaken to identify candidate materials for a pair of lightly loaded timing gears operating under highly humid conditions. The target application involves water purification and thus precludes the use of oil, grease and potentially toxic solid lubricants. The baseline sliding pair is austenitic stainless steel operating against a carbon filled polyimide. The test load and sliding speed (4.9 N, 2.7 m/s) were chosen to represent average contact conditions of the meshing gear teeth. In addition to the baseline materials, the hard superelastic NiTiNOL 60 (60NiTi) was slid against itself, against the baseline polyimide, and against 60NiTi onto which a commercially deposited dry film lubricant (DFL) was applied. The alternate materials were evaluated as potential replacements to achieve a longer wear life and improved dimensional stability for the timing gear application. An attempt was also made to provide solid lubrication to self-mated 60NiTi by rubbing the polyimide against the disk wear track outside the primary 60NiTi-60NiTi contact, a method named stick or transfer-film lubrication. The selected test conditions gave repeatable friction and wear data and smooth sliding surfaces for the baseline materials similar to those in the target application. Friction and wear for self-mated stainless steel were high and erratic. Self-mated 60NiTi gave acceptably low friction (approx. 0.2) and modest wear but the sliding surfaces were rough and potentially unsuitable for the gear application. Tests in which 60NiTi pins were slid against DFL coated 60NiTi and DFL coated stainless steel gave low friction and long wear life. The use of stick lubrication via the secondary polyimide pin provided effective transfer film lubrication to self-mated 60NiTi tribological specimens. Using this approach, friction levels were equal or lower than the baseline polyimide-stainless combination and wear was higher but within data scatter observed

  14. Protein purification using chromatography: selection of type, modelling and optimization of operating conditions.

    Science.gov (United States)

    Asenjo, J A; Andrews, B A

    2009-01-01

    To achieve a high level of purity in the purification of recombinant proteins for therapeutic or analytical application, it is necessary to use several chromatographic steps. There is a range of techniques available including anion and cation exchange, which can be carried out at different pHs, hydrophobic interaction chromatography, gel filtration and affinity chromatography. In the case of a complex mixture of partially unknown proteins or a clarified cell extract, there are many different routes one can take in order to choose the minimum and most efficient number of purification steps to achieve a desired level of purity (e.g. 98%, 99.5% or 99.9%). This review shows how an initial 'proteomic' characterization of the complex mixture of target protein and protein contaminants can be used to select the most efficient chromatographic separation steps in order to achieve a specific level of purity with a minimum number of steps. The chosen methodology was implemented in a computer- based Expert System. Two algorithms were developed, the first algorithm was used to select the most efficient purification method to separate a protein from its contaminants based on the physicochemical properties of the protein product and the protein contaminants and the second algorithm was used to predict the number and concentration of contaminants after each separation as well as protein product purity. The application of the Expert System approach was experimentally tested and validated with a mixture of four proteins and the experimental validation was also carried out with a supernatant of Bacillus subtilis producing a recombinant beta-1,3-glucanase. Once the type of chromatography is chosen, optimization of the operating conditions is essential. Chromatographic elution curves for a three-protein mixture (alpha-lactoalbumin, ovalbumin and beta-lactoglobulin), carried out under different flow rates and ionic strength conditions, were simulated using two different mathematical

  15. Experimental investigation of mixing of non-isothermal water streams at BWR operating conditions

    Energy Technology Data Exchange (ETDEWEB)

    Bergagio, Mattia, E-mail: bergagio@kth.se [AlbaNova University Center, Nuclear Reactor Technology Division, Department of Physics, Royal Institute of Technology, 106 91 Stockholm (Sweden); Anglart, Henryk, E-mail: henryk@kth.se [AlbaNova University Center, Nuclear Reactor Technology Division, Department of Physics, Royal Institute of Technology, 106 91 Stockholm (Sweden); Institute of Heat Engineering, Warsaw University of Technology, 21/25 Nowowiejska Street, 00-665 Warsaw (Poland)

    2017-06-15

    Highlights: • Temperatures are measured in the presence of mixing at BWR operating conditions. • The thermocouple support is moved along a pattern to extend the measurement region. • Uncertainty of 1.58 K for temperatures acquired at 1000 Hz. • Momenta of the hot streams and thermal stratification affect the data examined. • Unconventional spectral analysis is required to further study the data collected. - Abstract: In this experimental investigation, wall surface temperatures have been measured during mixing of three water streams in the annular gap between two coaxial stainless-steel tubes. The inner tube, with an outer diameter of 35 mm and a thickness of 5 mm, holds six K-type, ungrounded thermocouples with a diameter of 0.5 mm, which measured surface temperatures with a sampling rate of either 100 Hz or 1000 Hz. The tube was rotated from 0 to 360° and moved in a range of 387 mm in the axial direction to allow measurements of surface temperatures in the whole mixing region. The outer tube has an inner diameter of 80 mm and a thickness of 10 mm to withstand a water pressure of 9 MPa. A water stream at a temperature of either 333 K or 423 K and a Reynolds number between 1657 and 8410 rose vertically in the annular gap and mixed with two water streams at a temperature of 549 K and a Reynolds number between 3.56 × 10{sup 5} and 7.11 × 10{sup 5}. These two water streams entered the annulus radially on the same axial level, 180° apart. Water pressure was kept at 7.2 MPa. Temperature recordings were performed at five axial and eight azimuthal locations, for each set of boundary conditions. Each recording lasted 120 s to provide reliable data on the variance, intermittency and frequency of the surface temperature time series at hand. Thorough calculations indicate that the uncertainty in the measured temperature is of 1.58 K. The mixing region extends up to 0.2 m downward of the hot inlets. In most cases, measurements indicate non-uniform mixing in the

  16. Preliminary Two-Phase Terry Turbine Nozzle Models for RCIC Off-Design Operation Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Haihua [Idaho National Lab. (INL), Idaho Falls, ID (United States); O' Brien, James [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2017-06-12

    This report presents the effort to extend the single-phase analytical Terry turbine model to cover two-phase off-design conditions. The work includes: (1) adding well-established two-phase choking models – the Isentropic Homogenous Equilibrium Model (IHEM) and Moody’s model, and (2) theoretical development and implementation of a two-phase nozzle expansion model. The two choking models provide bounding cases for the two-phase choking mass flow rate. The new two-phase Terry turbine model uses the choking models to calculate the mass flow rate, the critical pressure at the nozzle throat, and steam quality. In the divergent stage, we only consider the vapor phase with a similar model for the single-phase case by assuming that the liquid phase would slip along the wall with a much slower speed and will not contribute the impulse on the rotor. We also modify the stagnation conditions according to two-phase choking conditions at the throat and the cross-section areas for steam flow at the nozzle throat and at the nozzle exit. The new two-phase Terry turbine model was benchmarked with the same steam nozzle test as for the single-phase model. Better agreement with the experimental data is observed than from the single-phase model. We also repeated the Terry turbine nozzle benchmark work against the Sandia CFD simulation results with the two-phase model for the pure steam inlet nozzle case. The RCIC start-up tests were simulated and compared with the single-phase model. Similar results are obtained. Finally, we designed a new RCIC system test case to simulate the self-regulated Terry turbine behavior observed in Fukushima accidents. In this test, a period inlet condition for the steam quality varying from 1 to 0 is applied. For the high quality inlet period, the RCIC system behaves just like the normal operation condition with a high pump injection flow rate and a nominal steam release rate through the turbine, with the net addition of water to the primary system; for

  17. Operant serial feature-positive conditional discrimination with composite features and different topography responses

    Directory of Open Access Journals (Sweden)

    J.L.O. Bueno

    2008-02-01

    Full Text Available In a serial feature-positive conditional discrimination procedure the properties of a target stimulus A are defined by the presence or not of a feature stimulus X preceding it. In the present experiment, composite features preceded targets associated with two different topography operant responses (right and left bar pressing; matching and non-matching-to-sample arrangements were also used. Five water-deprived Wistar rats were trained in 6 different trials: X-R®Ar and X-L®Al, in which X and A were same modality visual stimuli and the reinforcement was contingent to pressing either the right (r or left (l bar that had the light on during the feature (matching-to-sample; Y-R®Bl and Y-L®Br, in which Y and B were same modality auditory stimuli and the reinforcement was contingent to pressing the bar that had the light off during the feature (non-matching-to-sample; A- and B- alone. After 100 training sessions, the animals were submitted to transfer tests with the targets used plus a new one (auditory click. Average percentages of stimuli with a response were measured. Acquisition occurred completely only for Y-L®Br+; however, complex associations were established along training. Transfer was not complete during the tests since concurrent effects of extinction and response generalization also occurred. Results suggest the use of both simple conditioning and configurational strategies, favoring the most recent theories of conditional discrimination learning. The implications of the use of complex arrangements for discussing these theories are considered.

  18. Solar desiccant air-conditioning. Practical experience regarding operation and performance

    Energy Technology Data Exchange (ETDEWEB)

    Haller, A.; Trinkl, C.; Wittmann, R.; Zoerner, W. [Ingolstadt Univ. of Applied Sciences (Germany). Kompetenzzentrum Solartechnik; Hanby, V. [De Montfort Univ., Leicester (GB). Inst. of Energy and Sustainable Development (IESD)

    2007-07-01

    The Kompetenzzentrum Solartechnik of Ingolstadt University of Applied Sciences (Centre of Excellence for Solar Engineering) investigates the renewable-only based HVAC system of a multipurpose building. The 10.000 m{sup 2} gross floor area building is part of the biggest logistic-centre in the region serving the AUDI automobile production facilities. On the one hand, the investigation is supposed to demonstrate the potential of solar-assisted cooling, on the other hand, the monitoring, financed by the Bavarian Ministry of Environmental Affairs, focuses on the total energy balance of the building and the various innovative building technologies. Next to a ground source heat pump plant for base-load heating and cooling, the building is equipped with two arrays of solar-thermal flat-plate collectors (100 m{sup 2} of Conergy, Germany, and 180 m{sup 2} of Solahart, Australia) and a desiccant air-conditioning system (DEC, WOLF Anlagen-Technik, Germany). This consists of two plants with an air flow of 8.000 m{sup 3}/h and a nominal cooling capacity of 42 kW each. One of the two plants is monitored. The plant itself is considered a black box in a first approach, i.e. all incoming and outgoing energy flows and the air condition are measured. Apart from the investigation of the performance of the solar-assisted air-conditioning system, the feasibility of DEC-operation using flat-plate collectors available on the market is investigated. (orig.)

  19. A mathematical model for removal of human pathogenic viruses and bacteria by slow sand filtration under variable operational conditions

    NARCIS (Netherlands)

    Schijven, J.F.; Berg, H.H.J.L. van den; Colin, M.; Dullemont, Y.; Hijnen, W.A.M.; Magic-Knezev, A.; Oorthuizen, W.A.; Wubbels, G.

    2013-01-01

    Slow sand filtration (SSF) in drinking water production removes pathogenic microorganisms, but detection limits and variable operational conditions complicate assessment of removal efficiency. Therefore, amodel was developed to predict removal ofhuman pathogenic viruses and bacteria as a function of

  20. Modeling the Relationship between Vibration Features and Condition Parameters Using Relevance Vector Machines for Health Monitoring of Rolling Element Bearings under Varying Operation Conditions

    Directory of Open Access Journals (Sweden)

    Lei Hu

    2015-01-01

    Full Text Available Rotational speed and load usually change when rotating machinery works. Both this kind of changing operational conditions and machine fault could make the mechanical vibration characteristics change. Therefore, effective health monitoring method for rotating machinery must be able to adjust during the change of operational conditions. This paper presents an adaptive threshold model for the health monitoring of bearings under changing operational conditions. Relevance vector machines (RVMs are used for regression of the relationships between the adaptive parameters of the threshold model and the statistical characteristics of vibration features. The adaptive threshold model is constructed based on these relationships. The health status of bearings can be indicated via detecting whether vibration features exceed the adaptive threshold. This method is validated on bearings running at changing speeds. The monitoring results show that this method is effective as long as the rotational speed is higher than a relative small value.

  1. Optimum speech level to minimize listening difficulty in public spaces.

    Science.gov (United States)

    Kobayashi, Masaaki; Morimoto, Masayuki; Sato, Hiroshi; Sato, Hayato

    2007-01-01

    For ideal speech communication in public spaces, it is important to determine the optimum speech level for various background noise levels. However, speech intelligibility scores, which is conventionally used as the subjective listening test to measure the quality of speech communication, is near perfect in most everyday situations. For this reason, it is proposed to determine optimum speech levels for speech communication in public spaces by using listening difficulty ratings. Two kinds of listening test were carried out in this work. The results of the tests and our previous work [M. Morimoto, H. Sato, and M. Kobayashi, J. Acoust. Soc. Am. 116, 1607-1613 (2004)] are jointly discussed for suggesting the relation between the optimum speech level and background noise level. The results demonstrate that: (1) optimum speech level is constant when background noise level is lower than 40 dBA, (2) optimum speech level appears to be the level, which maintains around 15 dBA of SN ratio when the background noise level is more than 40 dBA, and (3) listening difficulty increases as speech level increases under the condition where SN ratio is good enough to keep intelligibility near perfect.

  2. Parametric Investigation of Optimum Thermal Insulation Thickness for External Walls

    Directory of Open Access Journals (Sweden)

    Omer Kaynakli

    2011-06-01

    Full Text Available Numerous studies have estimated the optimum thickness of thermal insulation materials used in building walls for different climate conditions. The economic parameters (inflation rate, discount rate, lifetime and energy costs, the heating/cooling loads of the building, the wall structure and the properties of the insulation material all affect the optimum insulation thickness. This study focused on the investigation of these parameters that affect the optimum thermal insulation thickness for building walls. To determine the optimum thickness and payback period, an economic model based on life-cycle cost analysis was used. As a result, the optimum thermal insulation thickness increased with increasing the heating and cooling energy requirements, the lifetime of the building, the inflation rate, energy costs and thermal conductivity of insulation. However, the thickness decreased with increasing the discount rate, the insulation material cost, the total wall resistance, the coefficient of performance (COP of the cooling system and the solar radiation incident on a wall. In addition, the effects of these parameters on the total life-cycle cost, payback periods and energy savings were also investigated.

  3. Study on the optimum fermentation conditions of Aspergillus niger C-15 for the production of naringinase%Aspergillus niger C15产柚苷酶发酵条件的优化研究

    Institute of Scientific and Technical Information of China (English)

    李志坚; 谭兴和; 李高阳

    2012-01-01

    The fermentation conditions for Aspergillus niger C15 naringinase production were optimalized by orthogonal experiment.The experimental result indicated that the best fermentation conditions was as follows:2% citrus peel meal and 6% soybean meal,30mL culture media in 250mL beaker flask,3% inoculation amount,initial pH 5,incubation temperature 30℃,time 100h.Under these optimized conditions,the yielding capacity of naringinase by the mutant was 1395.9U/mL,which was increased by 8.6% compared with the initial level(1285.6U/mL).Proper quantity of K2HPO4 and MgSO4 could improve naringinase production,CuSO4,FeSO4 were bad for producing enzyme.%通过正交实验对黑曲霉菌株C15产柚苷酶的发酵条件进行了优化。实验结果表明,Aspergillus niger C15菌株的最优产酶发酵条件为:2%桔皮粉、6%豆粕粉,250mL三角瓶中装料30mL,接种量3%,最适初始pH为5.0,30℃条件下培养100h,产酶量可达1395.9U/mL。与原始产酶条件相比,产酶量提高8.6%。不同的金属离子对产酶有不同的作用,添加适量的K2HPO4、MgSO4对产酶有明显的促进作用,CuSO4、FeSO4对产酶起抑制作用。

  4. Optimum viscous flow in pressure-swirl atomizers

    Science.gov (United States)

    Amini, Ghobad; Pereira, Aaron; Yun, Sangsig; Li, Xianguo

    2013-11-01

    Due to their simple configuration and reliable operation, pressure-swirl atomizers are widely used in applications such as combustion, painting, humidification, and sprinkling. The liquid is swirled by entering into the atomizer tangentially and its surface area is increased as discharges in a large spray angle. Understanding the effects of nozzle geometry and inlet flow condition on the discharge coefficient and spray angle is very important in nozzle design. To this end, the flow field inside a pressure-swirl atomizer has been studied theoretically. The main body of the liquid is taken to be moving in circles round the axis. Within the boundary layer, containing transverse and longitudinal velocity components, the retarded liquid is slowed down by viscosity and driven towards the exit orifice by pressure gradient. The swirling motion of liquid creates a low pressure zone near the nozzle axis and leads to the formation of a helical air-core. Through studying the growth of the boundary layer from nozzle entry to the orifice exit, the portions of the outflow exits the orifice from boundary layer current and also from the main body of the swirling liquid are specified. For a given range of pressure drop values, the optimum nozzle geometry and liquid flowrate are predicted. Additionally, the reason of increasing the flow by increasing liquid viscosity or decreasing orifice diameter is explained. A series of experiments and numerical modeling have also been carried out to support the theoretical results.

  5. Research on the Optimum Degradation Conditions of Atrazine by White Rot Fungi Laccase%白腐菌漆酶对莠去津最适降解条件的探讨

    Institute of Scientific and Technical Information of China (English)

    程科; 毕云枫; 沈明浩

    2012-01-01

    [目的]将白腐菌Coprinopsis cinerea okayama 7#130漆酶对三嗪类农药莠去津的降解条件进行了研究.[方法]向纯漆酶溶液中加入一定浓度的莠去津溶液进行降解反应,采用HPLC测定其含量,计算降解率.利用Box-Behnken设计对影响降解此农药的关键因素进行优化.[结果]经Design-Expert软件二次回归分析,得到莠去津降解的最适条件:pH值为6.9,温度为38.3℃,反应体系体积为5.3 mL,转速为186 r/min.在此条件下,莠去津降解率响应预测值为52.41%,验证值为52.32%.[结论]最适条件下的降解率提高了10%~15%,这为降低莠去津对环境的危害提供了科学依据.%[Aims] The degradation conditions of triazine pesticide atrazine by white-rot fungi Coprinopsis cinerea okayama7# 130 laccase were studied. [Methods] Some certain concentration of atrazine was added to the pure laccase solution before the degradation. The HPLC was performed to determine the content, and then the degradation rate was calculated. The key factors influencing the degradation of atrazine were optimized by Box-Behnken design. [Results] The result was undertaken by the second regression analysis using Design-Expert software, which showed that the optimal condition of the atrazine degrading was as follows: The pH value was 6.9, the temperature was 38.3 °C, the reaction volume was 5.3 mL, and the shaking speed was 186 r/min respectively. Under the optimal condition, the predicted value of the atrazine degradation rate was 52.41%, and the experimental value of atrazine degradation rate was 52.32%. [Conclusions] The degradation rate increased by 10-15% under the optimal condition, which provided the scientific basis to reduce the harm to the environment caused by atrazine.

  6. Hippocampal Homer1 levels influence motivational behavior in an operant conditioning task.

    Directory of Open Access Journals (Sweden)

    Klaus V Wagner

    Full Text Available Loss of motivation and learning impairments are commonly accepted core symptoms of psychiatric disorders such as depression and schizophrenia. Reward-motivated learning is dependent on the hippocampal formation but the molecular mechanisms that lead to functional incentive motivation in this brain region are still largely unknown. Recent evidence implicates neurotransmission via metabotropic glutamate receptors and Homer1, their interaction partner in the postsynaptic density, in drug addiction and motivational learning. As previous reports mainly focused on the prefrontal cortex and the nucleus accumbens, we now investigated the role of hippocampal Homer1 in operant reward learning in the present study. We therefore tested either Homer1 knockout mice or mice that overexpress Homer1 in the hippocampus in an operant conditioning paradigm. Our results show that deletion of Homer1 leads to a diverging phenotype that either displays an inability to perform the task or outstanding hyperactivity in both learning and motivational sessions. Due to the apparent bimodal distribution of this phenotype, the overall effect of Homer1 deletion in this paradigm is not significantly altered. Overexpression of hippocampal Homer1 did not lead to a significantly altered learning performance in any stage of the testing paradigm, yet may subtly contribute to emerging motivational deficits. Our results indicate an involvement of Homer1-mediated signaling in the hippocampus in motivation-based learning tasks and encourage further investigations regarding the specific molecular underpinnings of the phenotypes observed in this study. We also suggest to cautiously interpret the results of this and other studies regarding the phenotype following Homer1 manipulations in animals, since their behavioral phenotype appears to be highly diverse. Future studies would benefit from larger group sizes that would allow splitting the experimental groups in responders and non-responders.

  7. Computational Fluid Dynamics Based Investigation of Sensitivity of Furnace Operational Conditions to Burner Flow Controls

    Energy Technology Data Exchange (ETDEWEB)

    Marc Cremer; Kirsi St. Marie; Dave Wang

    2003-04-30

    This is the first Semiannual Technical Report for DOE Cooperative Agreement No: DE-FC26-02NT41580. The goal of this project is to systematically assess the sensitivity of furnace operational conditions to burner air and fuel flows in coal fired utility boilers. Our approach is to utilize existing baseline furnace models that have been constructed using Reaction Engineering International's (REI) computational fluid dynamics (CFD) software. Using CFD analyses provides the ability to carry out a carefully controlled virtual experiment to characterize the sensitivity of NOx emissions, unburned carbon (UBC), furnace exit CO (FECO), furnace exit temperature (FEGT), and waterwall deposition to burner flow controls. The Electric Power Research Institute (EPRI) is providing co-funding for this program, and instrument and controls experts from EPRI's Instrument and Controls (I&C) Center are active participants in this project. This program contains multiple tasks and good progress is being made on all fronts. A project kickoff meeting was held in conjunction with NETL's 2002 Sensors and Control Program Portfolio Review and Roadmapping Workshop, in Pittsburgh, PA during October 15-16, 2002. Dr. Marc Cremer, REI, and Dr. Paul Wolff, EPRI I&C, both attended and met with the project COR, Susan Maley. Following the review of REI's database of wall-fired coal units, the project team selected a front wall fired 150 MW unit with a Riley Low NOx firing system including overfire air for evaluation. In addition, a test matrix outlining approximately 25 simulations involving variations in burner secondary air flows, and coal and primary air flows was constructed. During the reporting period, twenty-two simulations have been completed, summarized, and tabulated for sensitivity analysis. Based on these results, the team is developing a suitable approach for quantifying the sensitivity coefficients associated with the parametric tests. Some of the results of the CFD

  8. Hydrothermal Testing of K Basin Sludge and N Reactor Fuel at Sludge Treatment Project Operating Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Delegard, Calvin H.; Schmidt, Andrew J.; Thornton, Brenda M.

    2007-03-30

    The Sludge Treatment Project (STP), managed for the U. S. DOE by Fluor Hanford (FH), was created to design and operate a process to eliminate uranium metal from K Basin sludge prior to packaging for Waste Isolation Pilot Plant (WIPP). The STP process uses high temperature liquid water to accelerate the reaction, produce uranium dioxide from the uranium metal, and safely discharge the hydrogen. Under nominal process conditions, the sludge will be heated in pressurized water at 185°C for as long as 72 hours to assure the complete reaction (corrosion) of up to 0.25-inch diameter uranium metal pieces. Under contract to FH, the Pacific Northwest National Laboratory (PNNL) conducted bench-scale testing of the STP hydrothermal process in November and December 2006. Five tests (~50 ml each) were conducted in sealed, un-agitated reaction vessels under the hydrothermal conditions (e.g., 7 to 72 h at 185°C) of the STP corrosion process using radioactive sludge samples collected from the K East Basin and particles/coupons of N Reactor fuel also taken from the K Basins. The tests were designed to evaluate and understand the chemical changes that may be occurring and the effects that any changes would have on sludge rheological properties. The tests were not designed to evaluate engineering aspects of the process. The hydrothermal treatment affected the chemical and physical properties of the sludge. In each test, significant uranium compound phase changes were identified, resulting from dehydration and chemical reduction reactions. Physical properties of the sludge were significantly altered from their initial, as-settled sludge values, including, shear strength, settled density, weight percent water, and gas retention.

  9. On Optimum Causal Cognitive Spectrum Reutilization Strategy

    CERN Document Server

    Haghighi, Kasra; Agrell, Erik

    2011-01-01

    In this paper we study opportunistic transmission strategies for cognitive radios (CR) in which causal noisy observation from a primary user(s) (PU) state is available. PU is assumed to be operating in a slotted manner, according to a two-state Markov model. The objective is to maximize utilization ratio (UR), i.e., relative number of the PU-idle slots that are used by CR, subject to interference ratio (IR), i.e., relative number of the PU-active slots that are used by CR, below a certain level. We introduce an a-posteriori LLR-based cognitive transmission strategy and show that this strategy is optimum in the sense of maximizing UR given a certain maximum allowed IR. Two methods for calculating threshold for this strategy in practical situations are presented. One of them performs well in higher SNRs but might have too large IR at low SNRs and low PU activity levels, and the other is proven to never violate the allowed IR at the price of a reduced UR. In addition, an upper-bound for the UR of any CR strategy...

  10. Optimization of operating conditions of distillation columns: an energy saving option in refinery industry

    Directory of Open Access Journals (Sweden)

    Alireza Fazlali

    2010-01-01

    Full Text Available While energy prices continue to climb, it conservation remains the prime concern for process industries. The daily growth of energy consumption throughout the world and the real necessity of providing it, shows that optimization of energy generation and consumption units is an economical and sometimes vital case. Hence, the optimization of a petroleum refinery is aimed towards great production and an increase in quality. In this research, the atmospheric distillation unit of the Iran-Arak-Shazand petroleum refinery was subject to optimization efforts. It was performed by the means of using a simulator with the aim to earn more overhead products. In the next step the optimization results from the simulators were carried out in the real world, at the above mentioned unit. Results demonstrate that the changes in the real operating conditions increase the overhead products with desirable quality. Finally, a net economical balance between the increments of the overhead products and the energy consumption shows an energy saving in this refinery.

  11. Predictions of structural integrity of steam generator tubes under normal operating, accident, an severe accident conditions

    Energy Technology Data Exchange (ETDEWEB)

    Majumdar, S. [Argonne National Lab., IL (United States)

    1997-02-01

    Available models for predicting failure of flawed and unflawed steam generator tubes under normal operating, accident, and severe accident conditions are reviewed. Tests conducted in the past, though limited, tended to show that the earlier flow-stress model for part-through-wall axial cracks overestimated the damaging influence of deep cracks. This observation was confirmed by further tests at high temperatures, as well as by finite-element analysis. A modified correlation for deep cracks can correct this shortcoming of the model. Recent tests have shown that lateral restraint can significantly increase the failure pressure of tubes with unsymmetrical circumferential cracks. This observation was confirmed by finite-element analysis. The rate-independent flow stress models that are successful at low temperatures cannot predict the rate-sensitive failure behavior of steam generator tubes at high temperatures. Therefore, a creep rupture model for predicting failure was developed and validated by tests under various temperature and pressure loadings that can occur during postulated severe accidents.

  12. Is fumigation enough for air conditioning units in operation theatres and Intensive care units?

    Directory of Open Access Journals (Sweden)

    Anasua Deb

    2016-05-01

    Full Text Available Background: Strict asepsis is necessary in operating theatres (OT and intensive care units (ICU as the patients undergo invasive procedures. The filters of contaminated air conditioning (AC units provide a niche for proliferation of fungi and production of fungal spores. Methods: The routine procedure for maintenance of sterile atmosphere in our hospital, i.e. fumigation and mopping walls with disinfectants often fail to address these fungal spores of the AC filters. We therefore carried out a surveillance of the ACs in ICUs and OTs to find the level of contamination with fungal spores and also to improvise on intervention strategies to tackle the problem. Over 3 months period, 34 ACs from 7 OTs and 2 ICUs were screened by taking 2 swabs from each AC which were then tested for the presence of fungal spores as per standard methods. Results: The contamination rate was 88.2% before fumigation and 76.9% after fumigation. The fungal spore contamination rate was reduced to 20% (1 out of 5 ACs after servicing of the ACs was done. Aspergillus spp. was the most common fungal isolate. Conclusion: Based on the observations, we recommend regular servicing of the ACs as well as wet mopping of the ducts with sporicidal solution at regular intervals. [Int J Res Med Sci 2016; 4(5.000: 1583-1589

  13. High Pressure Compression-Molding of α-Cellulose and Effects of Operating Conditions

    Directory of Open Access Journals (Sweden)

    Antoine Rouilly

    2013-05-01

    Full Text Available Commercial α-cellulose was compression-molded to produce 1A dog-bone specimens under various operating conditions without any additive. The resulting agromaterials exhibited a smooth, plastic-like surface, and constituted a suitable target as replacement for plastic materials. Tensile and three-points bending tests were conducted according to ISO standards related to the evaluation of plastic materials. The specimens had strengths comparable to classical petroleum-based thermoplastics. They also exhibited high moduli, which is characteristic of brittle materials. A higher temperature and higher pressure rate produced specimens with higher mechanical properties while low moisture content produced weaker specimens. Generally, the strong specimen had higher specific gravity and lower moisture content. However, some parameters did not follow the general trend e.g., thinner specimen showed much higher Young’s Modulus, although their specific gravity and moisture content remained similar to control, revealing a marked skin-effect which was confirmed by SEM observations.

  14. Overview of the deuterium inventory campaign in Tore Supra: Operational conditions and particle balance

    Energy Technology Data Exchange (ETDEWEB)

    Pegourie, B., E-mail: bernard.pegourie@cea.f [Association Euratom-CEA, CEA/DSM/IRFM, CEA Cadarache, F-13108 Saint-Paul-les-Durance cedex (France); Brosset, C.; Tsitrone, E.; Beaute, A.; Bremond, S.; Bucalossi, J.; Carpentier, S.; Corre, Y.; Delchambre, E.; Desgranges, C.; Devynck, P.; Douai, D.; Dunand, G.; Ekedahl, A. [Association Euratom-CEA, CEA/DSM/IRFM, CEA Cadarache, F-13108 Saint-Paul-les-Durance cedex (France); Escarguel, A. [PIIM, CNRS/Universite de Provence, F-13397 Marseille (France); Gauthier, E.; Gunn, J.P.; Hertout, P.; Hong, S.-H.; Kazarian, F. [Association Euratom-CEA, CEA/DSM/IRFM, CEA Cadarache, F-13108 Saint-Paul-les-Durance cedex (France)

    2009-06-15

    A specific experiment was performed in Tore Supra, dedicated to the search for consistency between wall inventories estimated from gas balance and post-mortem analysis and to the characterization of the D-retention mechanism. More than 160 similar discharges were performed, representing a cumulative time of 18 000 s of plasma with no intermediate conditioning procedure. The only significant operational issue was linked to the ejection of flakes from the plasma facing components, whose frequency increased dramatically during the campaign, triggering a plasma detachment phase followed by a disruption in number of cases. In-vessel inventory was increased by approx3.1 x 10{sup 24} D, and constant retention rate (approx2.3 x 10{sup 20} D/s averaged over discharge duration) was measured, with no indication of wall saturation. First measurements on dismantled tiles of the Toroidal Pump Limiter (TPL) show [D]/[C] ratios ranging from 0.04 to 0.20, on a typical thickness of 15-20 mum. Extrapolated to the whole TPL, this yields an amount of approx(1.5 +- 0.3) x 10{sup 24} D, i.e. approx50% of the estimated in-vessel inventory.

  15. Neutronics and Fuel Performance Evaluation of Accident Tolerant Fuel under Normal Operation Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Xu Wu; Piyush Sabharwall; Jason Hales

    2014-07-01

    This report details the analysis of neutronics and fuel performance analysis for enhanced accident tolerance fuel, with Monte Carlo reactor physics code Serpent and INL’s fuel performance code BISON, respectively. The purpose is to evaluate two of the most promising candidate materials, FeCrAl and Silicon Carbide (SiC), as the fuel cladding under normal operating conditions. Substantial neutron penalty is identified when FeCrAl is used as monolithic cladding for current oxide fuel. From the reactor physics standpoint, application of the FeCrAl alloy as coating layer on surface of zircaloy cladding is possible without increasing fuel enrichment. Meanwhile, SiC brings extra reactivity and the neutron penalty is of no concern. Application of either FeCrAl or SiC could be favorable from the fuel performance standpoint. Detailed comparison between monolithic cladding and hybrid cladding (cladding + coating) is discussed. Hybrid cladding is more practical based on the economics evaluation during the transition from current UO2/zircaloy to Accident Tolerant Fuel (ATF) system. However, a few issues remain to be resolved, such as the creep behavior of FeCrAl, coating spallation, inter diffusion with zirconium, etc. For SiC, its high thermal conductivity, excellent creep resistance, low thermal neutron absorption cross section, irradiation stability (minimal swelling) make it an excellent candidate materials for future nuclear fuel/cladding system.

  16. Evaluation of the performance degradation at PAFC effect of operating conditions on acid loss

    Energy Technology Data Exchange (ETDEWEB)

    Miyoshi, Hideaki; Uchida, Hiroyuki; Watanabe, Masahiro [Yamanashi Univ., Kofu (Japan)] [and others

    1996-12-31

    As a complimentary research project to the demonstration project of 5MW and 1 MW PAFC plants, the mechanism and rate of deterioration of the cells and stacks have been studied from 1995 FY conducted by NEDO, with the objective of establishing an estimation method for the service life-time of the cell stacks. As part of this project, this work has been performed to clarify basic phenomena of the performance degradation at PAFCs jointly by Yamanashi University, PAFC-TRA and PAFC manufacturers. The acid loss into exhaust gases is one of life limiting factors in PAFCs. To design the cells of long-life, it is important to estimate the phosphoric acid loss and to contrive ideas eliminating it. With the objective of obtaining basic data for simulating the acid loss in the large size cells, the effect of the operating conditions on the acid loss into exhaust gases has been studied experimentally by using a single cell with an active electrode area of 100 cm{sup 2}.

  17. Thermal Impact of Operating Conditions on the Performance of a Combined Cycle Gas Turbine

    Directory of Open Access Journals (Sweden)

    Thamir K. Ibrahim

    2012-08-01

    Full Text Available The combined cycle gas-turbine (CCGT power plant is a highly developed technology which generates electricalpower at high efficiencies. The first law of thermodynamics is used for energy analysis of the performance of theCCGT plant. The effects of varying the operating conditions (ambient temperature, compression ratio, turbine inlettemperature, isentropic compressor and turbine efficiencies, and mass flow rate of steam on the performance of theCCGT (overall efficiency and total output power were investigated. The programming of the performance model forCCGT was developed utilizing MATLAB software. The simulation results for CCGT show that the overall efficiencyincreases with increases in the compression ratio and turbine inlet temperature and with decreases in ambienttemperature. The total power output increases with increases in the compression ratio, ambient temperature, andturbine inlet temperature. The peak overall efficiency was reached with a higher compression ratio and low ambienttemperature. The overall efficiencies for CCGT were very high compared to the thermal efficiency of GT plants. Theoverall thermal efficiency of the CCGT quoted was around 57%; hence, the compression ratios, ambient temperature,turbine inlet temperature, isentropic compressor and turbine efficiencies, and mass flow rate of steam have a stronginfluence on the overall performance of the CCGT cycle.

  18. Commissioning and first operation of the pCVD diamond ATLAS Beam Conditions Monitor

    CERN Document Server

    Dobos, D

    2009-01-01

    The main aim of the ATLAS Beam Conditions Monitor is to protect the ATLAS Inner Detector silicon trackers from high radiation doses caused by LHC beam incidents, e.g. magnet failures. The BCM uses in total 16 1x1 cm2 500 μm thick polycrystalline chemical vapor deposition (pCVD) diamond sensors. They are arranged in 8 positions around the ATLAS LHC interaction point. Time difference measurements with sub nanosecond resolution are performed to distinguish between particles from a collision and spray particles from a beam incident. An abundance of the latter leads the BCM to provoke an abort of the LHC beam. A FPGA based readout system with a sampling rate of 2.56 GHz performs the online data analysis and interfaces the results to ATLAS and the beam abort system. The BCM diamond sensors, the detector modules and their readout system are described. Results of the operation with the first LHC beams are reported and results of commissioning and timing measurements (e.g. with cosmic muons) in preparation for first ...

  19. Improvement in operating conditions of coke oven batteries with long service life

    Energy Technology Data Exchange (ETDEWEB)

    Obertenev, V.N.; Bondarchuk, P.N.; Krut' ko, I.G.; Sheptovitskii, M.S.; Kaftan, Yu.S.; Shul' ga, I.V.; Vol' fovskii, A.G. (Mariupol' skii Koksokhimicheskii Zavod (USSR))

    1991-01-01

    Discusses operation of the coke oven battery No 1 in the Mariupol' coking plant constructed in 1949. Twenty-five of 69 coke oven chambers had liners deformed due to wear. In 1988-1989 a number of failures occurred due to accumulation of pyrolysis products and tar on coke oven walls. Excessive liner wear negatively influenced coking conditions (e.g. reducing the bulk density of charged coal, increasing the buildup on coke oven walls, increasing the density and viscosity of coal tar and content of solid particles in the tar). Increased viscosity and content of solid particles in the tar increased failure rates of a tar transport system. Coal tar properties in the Mariupol' plant and 8 other plants in the USSR are comparatively evaluated. Specific properties of coal tar from the Mariupol' plant and their causes were determined. On the basis of the evaluations coal tar properties were controlled by changing coal mixture composition (content of gas coal was reduced to 32% of G and GZh types). Reducing content of gas coal in the mixtures reduced coke oven failure rate, increased coke compression strength by 0.6% and reduced coke abrasion by 0.25%. 5 refs.

  20. Large-eddy simulation of propeller wake at design operating conditions

    Science.gov (United States)

    Kumar, Praveen; Mahesh, Krishnan

    2016-11-01

    Understanding the propeller wake is crucial for efficient design and optimized performance. The dynamics of the propeller wake are also central to physical phenomena such as cavitation and acoustics. Large-eddy simulation is used to study the evolution of the wake of a five-bladed marine propeller from near to far field at design operating condition. The computed mean loads and phase-averaged flow field show good agreement with experiments. The propeller wake consisting of tip and hub vortices undergoes streamtube contraction, which is followed by the onset of instabilities as evident from the oscillations of the tip vortices. Simulation results reveal a mutual induction mechanism of instability where instead of the tip vortices interacting among themselves, they interact with the smaller vortices generated by the roll-up of the blade trailing edge wake in the near wake. Phase-averaged and ensemble-averaged flow fields are analyzed to explain the flow physics. This work is supported by ONR.