WorldWideScience

Sample records for stack operating conditions

  1. The measurement of power reactor stack releases under accident conditions

    International Nuclear Information System (INIS)

    Stroem, L.

    1989-01-01

    The performance of a typical Swedish monitor for ventilation stack radioactivity releases is examined critically with respect to accident generated radioactive particles. The conditions in the stack, particle character, and the monitor design are considered. A large LOCA outside the containment leads to high relative humidity, and high temperature, or mist in the stack. A small external LOCA results in a moderate increase in temperature and humidity, and condensing conditions only with reduced ventilation. Particle size and stickiness are estimated for different types of accident. A particle is sticky if it adheres after contact with a solid, smooth, dry, and clean surface. The monitor performance is concluded to be poor for large, sticky particles, like mist droplets. Dense aerosols, like fire smoke, will plug the sampling filter. Non-sticky particles are generally sampled with acceptable accuracy. (au)

  2. Pressurized Operation of a Planar Solid Oxide Cell Stack

    DEFF Research Database (Denmark)

    Jensen, Søren Højgaard; Sun, Xiufu; Ebbesen, Sune Dalgaard

    2016-01-01

    Solid oxide cells (SOCs) can be operated either as fuel cells (SOFC) to convert fuels to electricity or as electrolyzers (SOEC) to convert electricity to fuels such as hydrogen or methane. Pressurized operation of SOCs provide several benefits on both cell and system level. If successfully matured...... (electrode performance) increases for thermodynamic and kinetic reasons, respectively. Further, the summit frequency of the gas concentration impedance arc and the pressure difference across the stack and heat exchangers is seen to decrease with increasing pressure following a power-law expression. Finally...

  3. Performance evaluation of an open-cathode PEM fuel cell stack under ambient conditions: Case study of United Arab Emirates

    International Nuclear Information System (INIS)

    Al-Zeyoudi, Hend; Sasmito, Agus P.; Shamim, Tariq

    2015-01-01

    Highlights: • Performance evaluation of open-cathode PEM fuel cell stacks with forced air-convection. • Stack performance can vary up to 40% from winter to summer. • Hot and arid condition leads to membrane drying and performance deterioration. • Anode humidification improves the stack performance up to 40% during summer. - Abstract: The open-cathode polymer electrolyte membrane (PEM) fuel cell stack has been a promising candidate as a sustainable energy conversion system for replacing fossil fuel-based energy conversion devices in portable and automotive applications. As the ambient air is directly used to provide both oxidant and cooling, the complex cooling loop can be avoided which reduces the complexity and cost. However, the stack performance is highly affected by ambient conditions, i.e., ambient temperature and humidity. In this study, the effect of monthly ambient air conditions (temperature and humidity) is evaluated with respect to the stack’s power production performance as well as thermal, water and gas management by employing a validated three-dimensional open-cathode PEM fuel cell stack model. The annual climate data from the hot and arid environment of Abu Dhabi, United Arab Emirates (UAE) are used as a case study. The objective is to develop a better fundamental understanding of the interactions of physical phenomena in a fuel cell stack, which can assist in improving the performance and operation of an open-cathode PEM fuel cell-powered vehicle. The results indicate that the stack performance can vary significantly (up to 40%) from winter to summer, especially at high operating currents, with significant changes in the stack temperature and the water content at the membrane. Moreover, the anode humidification results in a significant improvement in the stack performance (up to 40%) in hot and dry conditions. However, a careful balance has to be struck between the humidifier parasitic load and the stack power.

  4. Long-term operation of a solid oxide cell stack for coelectrolysis of steam and CO2

    DEFF Research Database (Denmark)

    Agersted, Karsten; Chen, Ming; Blennow, Peter

    2016-01-01

    High temperature electrolysis based on solid oxide electrolysis cells (SOECs) is a promising technology for production of synthetic fuels. The SOEC units can be used for co-electrolysis of steam and CO2 to produce synthesis gas (syngas, CO+H2), which can be further processed to a variety...... consists of Ni/YSZ electrode supported SOEC cells with a footprint of 12X12 cm2. The co-electrolysis operation was carried out by supplying a mixture of 45 % CO2 + 45 % H2O + 10 % H2 to the stack operating with a fixed conversion of 39 % for steam and CO2. The stack was operated at different conditions...... of synthetic fuels such as methane, methanol or DME. Previously we have reported electrolysis operation of solid oxide cell stacks for periods up to about 1000 hours. In this work, operation of a Haldor Topsoe 8-cell stack (stack design of 2014) in co-electrolysis mode for 6000 hours is reported. The stack...

  5. Operant Conditioning and Education.

    Science.gov (United States)

    de Noronha, Mario

    A case study of a learning disabled 8-year-old with behavior disturbancs is presented to highlight the use of operant conditioning in cutting down educational costs and easing the teacher's class management problems. (CL)

  6. Operant Conditioning - Token Economy.

    Science.gov (United States)

    Montgomery, Jacqueline; McBurney, Raymond D.

    Described is an Operant Conditioning-Token Economy Program, teaching patients to be responsible for their own behavior, to make choices, and to be motivated to change. The program was instigated with mentally ill patients in a state hospital and was later used with institutionalized mentally handicapped groups. After two years, only four of the…

  7. Teachers and Operant Conditioning.

    Science.gov (United States)

    Frey, Sherman

    A survey was conducted of 406 elementary, middle, and secondary school teachers to determine their understanding, acceptance, and use of the principle of operant conditioning. The treatment of data was by percent and chi square analysis primarily according to sex, experience, degree, and position. Subjects reported that a) they believed that the…

  8. Operating state distinction and operation control methods of the fuel cell stack; Nenryo denchi sutakku no unten jotai hanbetsu hoho oyobi unten seigyo hoho

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, M.; Nakajima, H.; Shiraishi, K. [Equosu Resarch Co. Ltd., Tokyo (Japan)

    1997-09-19

    In the operation of the fuel cell stack, output decrease is caused by surplus or deficient water content in part or whole of the fuel cell stack. The purpose of the invention is to provide operating state distinction and operation control methods, whereby the output abnormality is discovered in the early stage, and is quickly adjusted to the normal state. In accordance with the invention, time course voltage patterns of the cell block, composed of one or plural unit cells in the fuel cell stack that has solid oxide films as electrolytes, are classified by various operation conditions of the fuel cell, and stored in the memory in advance. Time course voltage patterns are measured by one unit cell or by the cell block; operation conditions are judged, compared and calculated while the measured time course voltage patterns and the patterns in the memory are compared; proper setting of operation conditions is selected; and command for adjusting to the setting is delivered to the unit cell or cell block in the fuel cell stack. 6 figs.

  9. Characterisation of a Planar Solid Oxide Cell Stack Operated at Elevated Pressure

    DEFF Research Database (Denmark)

    Jensen, Søren Højgaard; Graves, Christopher R.; Chen, Ming

    2016-01-01

    be operated either as electrolysers (SOEC) to convert electricity to fuels such as hydrogen or methane, and as fuel cells (SOFC) to convert fuels to electricity. Both productivity and conversion efficiency can be improved if the SOC operation pressure can be increased from ambient pressure to 10-30 bar. Here...... we characterize an SOC stack operated at pressures from ambient pressure to 10 bar without fluctuations in the steam supply. The pressure dependency of stack temperature, cell area specific resistance (ASR), current-voltage (iV) curves, stack impedance spectra and pressure drop across the stack...... and heat exchangers is analyzed and the expected impact of pressurization on the hydrogen production cost is evaluated....

  10. Characterization of a Planar Solid Oxide Cell Stack Operated at Elevated Pressure

    DEFF Research Database (Denmark)

    Jensen, Søren Højgaard; Graves, Christopher R.; Chen, Ming

    2016-01-01

    be operated either as electrolyzers (SOEC) to convert electricity to fuels such as hydrogen or methane, and as fuel cells (SOFC) to convert fuels to electricity. Both productivity and conversion efficiency can be improved if the SOC operation pressure can be increased from ambient pressure to 10–30 bar....... In this paper we characterize an SOC stack operated at pressures from ambient pressure to 10 bar. The pressure dependency of stack temperature, cell area specific resistance (ASR), current-voltage (iV) curves, stack impedance spectra and pressure drop across the stack and heat exchangers is analyzed...... in this paper. Additionally, the expected impact on the hydrogen production efficiency and cost is discussed....

  11. A small mono-polar direct methanol fuel cell stack with passive operation

    Science.gov (United States)

    Chan, Y. H.; Zhao, T. S.; Chen, R.; Xu, C.

    A passive direct methanol fuel cell (DMFC) stack that consists of six unit cells was designed, fabricated, and tested. The stack was tested with different methanol concentrations under ambient conditions. It was found that the stack performance increased when the methanol concentration inside the fuel tank was increased from 2.0 to 6.0 M. The improved performance is primarily due to the increased cell temperature as a result of the exothermic reaction between the permeated methanol and oxygen on the cathode. Moreover, the increased cell temperature enhanced the water evaporation rate on the air-breathing cathode, which significantly reduced water flooding on the cathode and further improved the stack performance. This passive DMFC stack, providing 350 mW at 1.8 V, was successfully applied to power a seagull display kit. The seagull display kit can continuously run for about 4 h on a single charge of 25 cm 3 4.0-M methanol solution.

  12. Study on component interface evolution of a solid oxide fuel cell stack after long term operation

    Science.gov (United States)

    Yang, Jiajun; Huang, Wei; Wang, Xiaochun; Li, Jun; Yan, Dong; Pu, Jian; Chi, Bo; Li, Jian

    2018-05-01

    A 5-cell solid oxide fuel cell (SOFC) stack with external manifold structure is assembled and underwent a durability test with an output of 250 W for nearly 4400 h when current density and operating temperature are 355 mA/cm2 and 750 °C. Cells used in the stack are anode-supported cells (ASC) with yttria-stabilized zirconia (YSZ) electrolytes, Ni/YSZ hydrogen electrodes, and YSZ based composite cathode. The dimension of the cell is 150 × 150 mm (active area: 130 × 130 mm). Ceramic-glass sealant is used in the stack to keep the gas tightness between cells, interconnects and manifolds. Pure hydrogen and dry air are used as fuel and oxidant respectively. The stack has a maximum output of 340 W at 562 mA/cm2 current density at 750 °C. The stack shows a degradation of 1.5% per 1000 h during the test with 2 thermal cycles to room temperature. After the test, the stack was dissembled and examined. The relationship between microstructure changes of interfaces and degradation in the stack are discussed. The microstructure evolution of interfaces between electrode, contact material and current collector are unveiled and their relationship with the degradation is discussed.

  13. Cooling Performance Characteristics of the Stack Thermal Management System for Fuel Cell Electric Vehicles under Actual Driving Conditions

    Directory of Open Access Journals (Sweden)

    Ho-Seong Lee

    2016-04-01

    Full Text Available The cooling performance of the stack radiator of a fuel cell electric vehicle was evaluated under various actual road driving conditions, such as highway and uphill travel. The thermal stability was then optimized, thereby ensuring stable operation of the stack thermal management system. The coolant inlet temperature of the radiator in the highway mode was lower than that associated with the uphill mode because the corresponding frontal air velocity was higher than obtained in the uphill mode. In both the highway and uphill modes, the coolant temperatures of the radiator, operated under actual road driving conditions, were lower than the allowable limit (80 °C; this is the maximum temperature at which stable operation of the stack thermal management system of the fuel cell electric vehicle could be maintained. Furthermore, under actual road driving conditions in uphill mode, the initial temperature difference (ITD between the coolant temperature and air temperature of the system was higher than that associated with the highway mode; this higher ITD occurred even though the thermal load of the system in uphill mode was greater than that corresponding to the highway mode. Since the coolant inlet temperature is expected to exceed the allowable limit (80 °C in uphill mode under higher ambient temperature with air conditioning system operation, the FEM design layout should be modified to improve the heat capacity. In addition, the overall volume of the stack cooling radiator is 52.2% higher than that of the present model and the coolant inlet temperature of the improved radiator is 22.7% lower than that of the present model.

  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. Safety Evaluation of Radioactive Material Transport Package under Stacking Test Condition

    International Nuclear Information System (INIS)

    Lee, Ju Chan; Seo, Ki Seog; Yoo, Seong Yeon

    2012-01-01

    Radioactive waste transport package was developed to transport eight drums of low and intermediate level waste(LILW) in accordance with the IAEA and domestic related regulations. The package is classified with industrial package IP-2. IP-2 package is required to undergo a free drop test and a stacking test. After free drop and stacking tests, it should prevent the loss or dispersal of radioactive contents, and loss of shielding integrity which would result in more than 20 % increase in the radiation level at any external surface of the package. The objective of this study is to establish the safety test method and procedure for stacking test and to prove the structural integrities of the IP-2 package. Stacking test and analysis were performed with a compressive load equal to five times the weight of the package for a period of 24 hours using a full scale model. Strains and displacements were measured at the corner fitting of the package during the stacking test. The measured strains and displacements were compared with the analysis results, and there were good agreements. It is very difficult to measure the deflection at the container base, so the maximum deflection of the container base was calculated by the analysis method. The maximum displacement at the corner fitting and deflection at the container base were less than their allowable values. Dimensions of the test model, thickness of shielding material and bolt torque were measured before and after the stacking test. Throughout the stacking test, it was found that there were no loss or dispersal of radioactive contents and no loss of shielding integrity. Thus, the package was shown to comply with the requirements to maintain structural integrity under the stacking condition.

  16. Preparation and characterization of porphyrin-polythiophene stacked films as prepared by electrochemical method under stirring condition

    International Nuclear Information System (INIS)

    Sugawa, Kosuke; Akiyama, Tsuyoshi; Yamada, Sunao

    2008-01-01

    Porphyrin-polythiophene (pTh) stacked films consisting of meso-tetrathienylporphyrin (TThP) and bithiophene (BiTh) were prepared on transparent indium-tin-oxide (ITO) electrodes by sequential electrochemical scanning of applied potential between 0 and + 2 V vs Ag wire in the electrolyte solution of BiTh and TThP under stirring condition. First, the pTh films were prepared by electrochemical polymerization and then TThP was incorporated into the as-prepared pTh film by subsequent electrochemical scanning as described above in the TThP solution. The operation of solution stirring during electrochemical scanning achieved the formation of robust stacked films. UV/Vis and fluorescence spectra confirmed that the amount of TThP moiety increased with increasing the number of electrochemical scanning cycles in the TThP solution. In order to evaluate the incorporation profile of TThP, surface analyses and depth profiles of stacked films were carried out by XPS spectroscopy. The results suggested that all films formed porphyrin-polythiophene stacked structure precisely, and that TThP was exclusively incorporated around the outermost region of the pTh film

  17. Element stacking method for topology optimization with material-dependent boundary and loading conditions

    DEFF Research Database (Denmark)

    Yoon, Gil Ho; Park, Y.K.; Kim, Y.Y.

    2007-01-01

    A new topology optimization scheme, called the element stacking method, is developed to better handle design optimization involving material-dependent boundary conditions and selection of elements of different types. If these problems are solved by existing standard approaches, complicated finite...

  18. Pressurized reversible operation of a 30-cell solid oxide cell stack using carbonaceous gases

    DEFF Research Database (Denmark)

    Jensen, Søren Højgaard; Langnickel, Hendrik; Hintzen, N.

    2017-01-01

    Recent theoretical studies show that reversible electrochemical conversion of H2O and CO2 to CH4 inside pressurized solid oxide cells (SOCs) combined with subsurface storage of the produced gases can facilitate seasonal electricity storage with a round-trip efficiency reaching 70-80% and a storag...... in electrolysis mode. The degradation rates in both fuel cell and electrolysis mode were comparable to previously reported SOFCMAN stack degradation rates measured at ambient pressure operation with H2/H2O gas mixtures.......Recent theoretical studies show that reversible electrochemical conversion of H2O and CO2 to CH4 inside pressurized solid oxide cells (SOCs) combined with subsurface storage of the produced gases can facilitate seasonal electricity storage with a round-trip efficiency reaching 70-80% and a storage...... cost below 3 ¢/kWh. Here we show test results with a 30-cell SOFCMAN 301 stack operated with carbonaceous gases at 18.7 bar and 700 ˚C in both electrolysis and fuel cell mode. The CH4 content in the stack outlet gas increased from 0.22% at open circuit voltage (OCV) to 18% at -0.17 A cm-2...

  19. Electrochemical Impedance Spectroscopy (EIS) Characterization of Reformate-operated High Temperature PEM Fuel Cell Stack

    DEFF Research Database (Denmark)

    Sahlin, Simon Lennart; Simon Araya, Samuel; Andreasen, Søren Juhl

    2017-01-01

    their effects on a reformate-operated stack. Polarization curves were also recorded to complement the impedance analysis of the researched phenomena. An equivalent circuit model was used to estimate the different resistances at varying parameters. It showed a significantly higher low frequency resistance......, λanode= 1.6 for reformate operation and λcathode= 4.The work also compared dry hydrogen, steam reforming and autothermal reforming gas feeds at160 ◦Cand showed appreciably lower performance in the case of autothermal reforming at the same stoichiometry, mainly attributable to mass transport related...

  20. 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.

  1. Local degradation analysis of a real long-term operated DMFC stack MEA

    Science.gov (United States)

    Hartmann, Peter; Gerteisen, Dietmar

    2012-12-01

    Understanding degradation of the membrane-electrode assembly (MEA) of direct methanol fuel cells (DMFC) is important technically and scientifically for the advancement of this technology. In this work, we carry out a spatially resolved investigation of the degradation of an MEA, which has been degraded through its operation lifetime. The MEA has an active area of 320 cm2 and has been used in operation of a DMFC stack for more than 3000 h to power a lift truck. The analysis of degradation with respect to the local position of the flow field pattern was carried out by cutting the MEA into small pieces that are characterized in a 1 cm2 sized test cell with a reference electrode setup. The characterization techniques involved measurement of anode and cathode polarization curves, electrode potential relaxation curves after current interruption, MeOH-stripping voltammograms, cyclic voltammetry and SEM/EDX analysis. The MEA pieces were prepared by Laser ablation technique to realize the reference electrodes. The analysis yielded an independence of performance from the local position of the MEAs within the stack in terms of the anode and cathode flow fields.

  2. Energy levels of ABC-stacked trilayer graphene quantum dots with infinite-mass boundary conditions

    Science.gov (United States)

    Mirzakhani, M.; Zarenia, M.; da Costa, D. R.; Ketabi, S. A.; Peeters, F. M.

    2016-10-01

    Using the continuum model, we investigate the confined states and the corresponding wave functions of ABC-stacked trilayer graphene (TLG) quantum dots (QDs). First, a general infinite-mass boundary condition is derived and applied to calculate the electron and hole energy levels of a circular QD in both the absence and presence of a perpendicular magnetic field. Our analytical results for the energy spectra agree with those obtained by using the tight-binding model, where a TLG QD is surrounded by a staggered potential. Our findings show that (i ) the energy spectrum exhibits intervalley symmetry EKe(m ) =-EK'h(m ) for the electron (e) and hole (h) states, where m is the angular momentum quantum number, (i i ) the zero-energy Landau level (LL) is formed by the magnetic states with m ⩽0 for both Dirac valleys, that is different from monolayer and bilayer graphene QD with infinite-mass potential in which only one of the cones contributes, and (i i i ) groups of three quantum Hall edge states in the tight-binding magnetic spectrum approach the zero LL, which results from the layer symmetry in TLG QDs.

  3. Segmentation of RGB-D indoor scenes by stacking random forests and conditional random fields

    DEFF Research Database (Denmark)

    Thøgersen, Mikkel; Guerrero, Sergio Escalera; Gonzàlez, Jordi

    2016-01-01

    on stacked classifiers; the benefits are two fold: on one hand, the system scales well to consider different types of complex features and, on the other hand, the use of stacked classifiers makes the performance of the proposed technique more accurate. The proposed method consists of a random forest using...... a stacked random forest which gives the final predictions. The model is tested on the renown NYU-v2 dataset and the recently available SUNRGBD dataset. The approach shows that simple multimodal features with the power of using multi-class multi-scale stacked sequential learners (MMSSL) can achieve slight...... better performance than state of the art methods on the same dataset. The results show an improvement of 2.3% over the base model by using MMSSL and displays that the method is effective in this problem domain....

  4. A Force Sensorless Method for CFRP/Ti Stack Interface Detection during Robotic Orbital Drilling Operations

    Directory of Open Access Journals (Sweden)

    Qiang Fang

    2015-01-01

    Full Text Available Drilling carbon fiber reinforced plastics and titanium (CFRP/Ti stacks is one of the most important activities in aircraft assembly. It is favorable to use different drilling parameters for each layer due to their dissimilar machining properties. However, large aircraft parts with changing profiles lead to variation of thickness along the profiles, which makes it challenging to adapt the cutting parameters for different materials being drilled. This paper proposes a force sensorless method based on cutting force observer for monitoring the thrust force and identifying the drilling material during the drilling process. The cutting force observer, which is the combination of an adaptive disturbance observer and friction force model, is used to estimate the thrust force. An in-process algorithm is developed to monitor the variation of the thrust force for detecting the stack interface between the CFRP and titanium materials. Robotic orbital drilling experiments have been conducted on CFRP/Ti stacks. The estimate error of the cutting force observer was less than 13%, and the stack interface was detected in 0.25 s (or 0.05 mm before or after the tool transited it. The results show that the proposed method can successfully detect the CFRP/Ti stack interface for the cutting parameters adaptation.

  5. The resource theory under conditioned thermal operations

    OpenAIRE

    Narasimhachar, Varun; Gour, Gilad

    2016-01-01

    The "thermal operations" framework developed in past works is used to model the evolution of microscopic quantum systems in contact with thermal baths. Here we extend this model to bipartite devices with one part acting as a control external to the system--bath setup. We define the operations of such hybrid devices as conditioned thermal operations. We examine the resource under these operations, which we call conditional athermality. In the quasiclassical limit, we quantify this resource and...

  6. Simulation of a tubular solid oxide fuel cell stack using AspenPlusTM unit operation models

    International Nuclear Information System (INIS)

    Zhang, W.; Croiset, E.; Douglas, P.L.; Fowler, M.W.; Entchev, E.

    2005-01-01

    The design of a fuel cell system involves both optimization of the fuel cell stack and the balance of plant with respect to efficiency and economics. Many commercially available process simulators, such as AspenPlus TM , can facilitate the analysis of a solid oxide fuel cell (SOFC) system. A SOFC system may include fuel pre-processors, heat exchangers, turbines, bottoming cycles, etc., all of which can be very effectively modelled in process simulation software. The current challenge is that AspenPlus TM or any other commercial process simulators do not have a model of a basic SOFC stack. Therefore, to enable performing SOFC system simulation using one of these simulators, one must construct an SOFC stack model that can be implemented in them. The most common approach is to develop a complete SOFC model in a programming language, such as Fortran, Visual Basic or C++, first and then link it to a commercial process simulator as a user defined model or subroutine. This paper introduces a different approach to the development of a SOFC model by utilizing existing AspenPlus TM functions and existing unit operation modules. The developed ''AspenPlus TM SOFC'' model is able to provide detailed thermodynamic and parametric analyses of the SOFC operation and can easily be extended to study the entire power plant consisting of the SOFC and the balance of plant without the requirement for linking with other software. Validation of this model is performed by comparison to a Siemens-Westinghouse 100 kW class tubular SOFC stack. Sensitivity analyses of major operating parameters, such as utilization factor (U f ), current density (I c ) and steam-carbon ratio (S/C), were performed using the developed model, and the results are discussed in this paper

  7. Teaching Operant Conditioning at the Zoo.

    Science.gov (United States)

    Lukas, Kristen E.; Marr, M. Jackson; Maple, Terry L.

    1998-01-01

    Describes a partnership between Zoo Atlanta and the Georgia Institute of Technology in teaching the principles of operant conditioning to students in an experimental psychology class. Maintains that the positive training techniques used in zoos are models of applied operant conditioning. Includes a discussion of zoo training goals. (MJP)

  8. Operation of a Five-Stage 40,000-CM2-Area Insulator Stack at 158 KV/CM

    International Nuclear Information System (INIS)

    We have demonstrated successful operation of a 3.35- m-diameter insulator stack at 158 kV/cm on five consecutive Z-accelerator shots. The stack consisted of five +45 deg;-profile 5.715-cm-thick cross-linked-polystyrene (Rexolite- 1422) insulator rings, and four anodized- aluminum grading rings shaped to reduce the field at cathode triple junctions. The width of the voltage pulse at 89% of peak was 32 ns. We compare this result to a new empirical flashover relation developed from previous small-insulator experiments conducted with flat unanodized electrodes. The relation predicts a 50% flashover probability for a Rexolite insulator during an applied voltage pulse when E max e -0.27/d (t eff C) 1/10 = 224, where E max is the peak mean electric field (kV/cm), d is the insulator thickness (cm), t eff is the effective pulse width (ps), and C is the insulator circumference (cm). We find the Z stack can be operated at a stress at least 19% higher than predicted. This result, and previous experiments conducted by Vogtlin, suggest anodized electrodes with geometries that reduce the field at both anode and cathode triple junctions would improve the flashover strength of +45 deg; insulators

  9. Independent determination of the accuracy of the OSTR stack gas monitor and its operational application

    International Nuclear Information System (INIS)

    Pickett, B.D.; Johnson, A.G.

    1982-01-01

    This study was undertaken to determine the accuracy of the stack gas monitor, using techniques which were independent of the monitoring system itself. Samples of argon-41 to be used as the standards in this study were carefully produced in the thermal column of the OSTR and counted on a Ge(Li) detector which was connected to a multichannel analyzer (MCA). As the argon-41 standard in the gas sample flask decayed, the concentration of the argon-41 was compared to the output of the Ge(Li)/MCA system. This established a calibration curve for the counting system, whereby a sample with an unknown concentration of argon-41 could be counted and the subsequent count rate from the sample converted to a concentration expressed in mCi per milliliter. Gas samples were extracted from various points in the reactor exhaust system and the concentrations of argon-41 were determined by counting on the Ge(Li)/MCA system. Each sample concentration was then compared to the argon-41 concentration indicated by the stack gas monitor. The initial results indicated that, although possibly intermittent, the argon-41 concentrations displayed by the stack gas monitor were often approximately 50% of those predicted by analysis of individual samples from the exhaust system. Several possible sources for the discrepancy were checked, including the method of SGM calibration, uneven mixing of exhaust air and argon-41 in the reactor building exhaust stream, and dilution of the gas concentration in the SGM system by air leakage into the system. After considerable effort, the latter cause was found to be the culprit, due to an aging gasket around the stack monitor's moving particulate-filter-paper housing

  10. 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.

  11. Program scheme using common source lines in channel stacked NAND flash memory with layer selection by multilevel operation

    Science.gov (United States)

    Kim, Do-Bin; Kwon, Dae Woong; Kim, Seunghyun; Lee, Sang-Ho; Park, Byung-Gook

    2018-02-01

    To obtain high channel boosting potential and reduce a program disturbance in channel stacked NAND flash memory with layer selection by multilevel (LSM) operation, a new program scheme using boosted common source line (CSL) is proposed. The proposed scheme can be achieved by applying proper bias to each layer through its own CSL. Technology computer-aided design (TCAD) simulations are performed to verify the validity of the new method in LSM. Through TCAD simulation, it is revealed that the program disturbance characteristics is effectively improved by the proposed scheme.

  12. The effect of test configuration on the true operating conditions of PEM fuel cells. Paper no. IGEC-1-124

    International Nuclear Information System (INIS)

    Simpson, T.; Li, X.

    2005-01-01

    The operating conditions of a single PEM fuel cell can be significantly affected by the configuration in which the fuel cell test is setup. This study investigates the effect on the gas dewpoint temperature of not insulating the inlet fittings to a PEM fuel cell and the effect of non-optimal stack control thermocouple placement on fuel cell stack operating temperature. Both of these setup configurations can significantly affect fuel cell membrane humidification conditions, especially in a single fuel cell as demonstrated through the sample test conditions presented in this paper. (author)

  13. Operant conditioning in the ant Myrmica sabuleti.

    Science.gov (United States)

    Cammaerts, M C

    2004-11-30

    Operant conditioning could be obtained in the ant Myrmica sabuleti by presenting to the workers, during a six-day period, an apparatus containing either sugared water or meat as a reward. The conditioning obtained using sugared water as a reward was short lasting. A reconditioning was more persistent and lasted four hours. The ants' response was very precise, since they exhibited it only in front of an apparatus identical to that used during the training phase. Operant conditioning obtained using meat as a reward was more pronounced than that obtained by using sugared water, probably because meat is more valuable as a reward than sugar for the species studied, which is essentially a carnivorous one. Such a conditioning was rather persistent. Indeed, a first operant conditioning obtained by using meat as a reward could still be detected after seven hours, and a reconditioning was still significant after eight hours. One day after this eight-hour period without rewarding the ants, the response was higher again and a further day later, it was still significant. Since the operant conditioning is easy to perform and quantify and since the ants' response is very precise, such a conditioning can be used for further studying M. sabuleti workers' visual perception.

  14. Operational Markov Condition for Quantum Processes

    Science.gov (United States)

    Pollock, Felix A.; Rodríguez-Rosario, César; Frauenheim, Thomas; Paternostro, Mauro; Modi, Kavan

    2018-01-01

    We derive a necessary and sufficient condition for a quantum process to be Markovian which coincides with the classical one in the relevant limit. Our condition unifies all previously known definitions for quantum Markov processes by accounting for all potentially detectable memory effects. We then derive a family of measures of non-Markovianity with clear operational interpretations, such as the size of the memory required to simulate a process or the experimental falsifiability of a Markovian hypothesis.

  15. Operant Conditioning and Learning: Examples, Sources, Technology.

    Science.gov (United States)

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

    The purpose of this paper is to relate psychology to teaching generally, and to relate behavior shaping to curriculum, specifically. Focusing on operant conditioning and learning, many studies are cited which illustrate some of the work being done toward effectively shaping or modifying student behavior whether in terms of subject matter or…

  16. 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.

  17. Operant conditioning of facial displays of pain.

    Science.gov (United States)

    Kunz, Miriam; Rainville, Pierre; Lautenbacher, Stefan

    2011-06-01

    The operant model of chronic pain posits that nonverbal pain behavior, such as facial expressions, is sensitive to reinforcement, but experimental evidence supporting this assumption is sparse. The aim of the present study was to investigate in a healthy population a) whether facial pain behavior can indeed be operantly conditioned using a discriminative reinforcement schedule to increase and decrease facial pain behavior and b) to what extent these changes affect pain experience indexed by self-ratings. In the experimental group (n = 29), the participants were reinforced every time that they showed pain-indicative facial behavior (up-conditioning) or a neutral expression (down-conditioning) in response to painful heat stimulation. Once facial pain behavior was successfully up- or down-conditioned, respectively (which occurred in 72% of participants), facial pain displays and self-report ratings were assessed. In addition, a control group (n = 11) was used that was yoked to the reinforcement plans of the experimental group. During the conditioning phases, reinforcement led to significant changes in facial pain behavior in the majority of the experimental group (p .136). Fine-grained analyses of facial muscle movements revealed a similar picture. Furthermore, the decline in facial pain displays (as observed during down-conditioning) strongly predicted changes in pain ratings (R(2) = 0.329). These results suggest that a) facial pain displays are sensitive to reinforcement and b) that changes in facial pain displays can affect self-report ratings.

  18. Optimization of Fuel Cell System Operating Conditions for Fuel Cell Vehicles

    OpenAIRE

    Zhao, Hengbing; Burke, Andy

    2008-01-01

    Proton Exchange Membrane fuel cell (PEMFC) technology for use in fuel cell vehicles and other applications has been intensively developed in recent decades. Besides the fuel cell stack, air and fuel control and thermal and water management are major challenges in the development of the fuel cell for vehicle applications. The air supply system can have a major impact on overall system efficiency. In this paper a fuel cell system model for optimizing system operating conditions was developed wh...

  19. Operational forecasting of human-biometeorological conditions

    Science.gov (United States)

    Giannaros, T. M.; Lagouvardos, K.; Kotroni, V.; Matzarakis, A.

    2018-03-01

    This paper presents the development of an operational forecasting service focusing on human-biometeorological conditions. The service is based on the coupling of numerical weather prediction models with an advanced human-biometeorological model. Human thermal perception and stress forecasts are issued on a daily basis for Greece, in both point and gridded format. A user-friendly presentation approach is adopted for communicating the forecasts to the public via the worldwide web. The development of the presented service highlights the feasibility of replacing standard meteorological parameters and/or indices used in operational weather forecasting activities for assessing the thermal environment. This is of particular significance for providing effective, human-biometeorology-oriented, warnings for both heat waves and cold outbreaks.

  20. Characterization of Piezoelectric Stacks for Space Applications

    Science.gov (United States)

    Sherrit, Stewart; Jones, Christopher; Aldrich, Jack; Blodget, Chad; Bao, Xiaoqi; Badescu, Mircea; Bar-Cohen, Yoseph

    2008-01-01

    Future NASA missions are increasingly seeking to actuate mechanisms to precision levels in the nanometer range and below. Co-fired multilayer piezoelectric stacks offer the required actuation precision that is needed for such mechanisms. To obtain performance statistics and determine reliability for extended use, sets of commercial PZT stacks were tested in various AC and DC conditions at both nominal and high temperatures and voltages. In order to study the lifetime performance of these stacks, five actuators were driven sinusoidally for up to ten billion cycles. An automated data acquisition system was developed and implemented to monitor each stack's electrical current and voltage waveforms over the life of the test. As part of the monitoring tests, the displacement, impedance, capacitance and leakage current were measured to assess the operation degradation. This paper presents some of the results of this effort.

  1. Post-test analysis of 20kW molten carbonate fuel cell stack operated on coal gas. Final report, August 1993--February 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-05-01

    A 20kW carbonate fuel cell stack was operated with coal gas for the first time in the world. The stack was tested for a total of 4,000 hours, of which 3,900 hours of testing was conducted at the Louisiana Gasification Technology Incorporated, Plaquemine, Louisiana outdoor site. The operation was on either natural gas or coal gas and switched several times without any effects, demonstrating duel fuel capabilities. This test was conducted with 9142 kJ/m{sup 3} (245 Btu/cft) coal gas provided by a slipstream from Destec`s entrained flow, slagging, slurry-fed gasifier equipped with a cold gas cleanup subsystem. The stack generated up to 21 kW with this coal gas. Following completion of this test, the stack was brought to Energy Research Corporation (ERC) and a detailed post-test analysis was conducted to identify any effects of coal gas on cell components. This investigation has shown that the direct fuel cell (DFC) can be operated with properly cleaned and humidified coal-as, providing stable performance. The basic C direct fuel cell component materials are stable and display normal stability in presence of the coal gas. No effects of the coal-borne contaminants are apparent. Further cell testing at ERC 1 17, confirmed these findings.

  2. Effective Work Procedure design Using Discomfort and Effort Factor in Brick stacking operation-A case study

    Science.gov (United States)

    Rout, Biswaranjan; Dash, R. R.; Dhupal, D.

    2018-02-01

    In this work a typical planning of movement of limbs and torso of the worker to be well design to reduce fatigue and energy of the worker. A simulation model is generated to suit the procedure and comply with the constraints in the workspace. It requires verifying the capability of human postures and movements in different working conditions for the evaluation of effectiveness of the new design. In this article a simple human performance measure is introduce that enable the mathematical model for evaluation of a cost function. The basic scheme is to evaluate the performance in the form of several cost factors using AI techniques. Here two main cost factors taken in to consideration are discomfort factor and effort factor in limb movements. Discomfort factor measures the level of discomfort from the most neutral position of a given limb to the position of the corresponding limb after movement and effort factor is a measure of the displacement of the corresponding limbs from the original position. The basic aim is to optimize the movement of the limbs with the above mentioned cost functions. The effectiveness of the procedure is tested with an example of working procedure of workers used for stacking of fly ash bricks in a local fly ash bricks manufacturing unit. The objective is to find out the optimised movement of the limbs to reduce discomfort level and effort required of workers. The effectiveness of the procedure in this case study illustrated with the obtained results.

  3. Operating conditions of the BPX divertor

    International Nuclear Information System (INIS)

    Hill, D.N.; Milovich, J.; Rognlien, T.; Braams, B.J.; Brooks, J.N.; Campbell, R.; Haines, J.; Knoll, D.; Prinja, A.; Stotler, D.P.; Ulrickson, M.

    1991-01-01

    In this paper we discuss the expected operating conditions at the divertor of the BPX tokamak (Burning Plasma Experiment), the next- step US tokamak proposed for the study of self-heated plasmas at Q ≅ 5 to ignition. In this double-null device (κ ≅ 2), the predicted first-wall loading is high because of is compact size (R = 2.6m, α = 0.8m, I p = 10.6 MA, and B T ) and its high projected fusion power output (100--500 MW with up to 20 MW of ICRH). Present designs call for inertially cooled carbon-based target plate material and X-point sweeping to handle the divertor heat flux during the 3--5 s flat-top at full power. The X-point is maintained about 15--20 cm off the target plates (a distance of ∼5m along field lines), which represents a reasonable compromise between lowering the divertor electron temperature (T e,d ) by increasing the connection length, and lowering the peak divertor heat flux (q d ) by increasing the magnetic flux expansion (which is about 15--20 in this case). It is planned for the BPX device to operate with H-mode confinement; ELMs are expected because of the relatively high power flow through the edge plasma (P sep ≅ 0.6 MW/m 2 for P fus = 500 MW). The ELMs will help reduce the impurity concentration in the core plasma (Z eff ≅ 1.7) and keep the density down, but should not add significantly to the divertor heat flux since their measured contribution to the global power balance drops with increasing input power

  4. 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.

  5. Algebraic stacks

    Indian Academy of Sciences (India)

    generally, any fiber product) is not uniquely defined: it is only defined up to unique isomorphism. ..... Fiber product. Given two morphisms f1 : F1 ! G, f2 : F2 ! G, we define a new stack. F1 آG F2 (with projections to F1 and F2) as follows. The objects are triples ًX1; X2; ق ..... In fact, any Artin stack F can be defined in this fashion.

  6. Use of impedance tagging to monitor fuel cell stack performance

    Science.gov (United States)

    Silva, Gregory

    Fuel cells are electrochemical device that are traditionally assembled in stacks to perform meaningful work. Monitoring the state of the stack is vitally important to ensure that it is operating efficiently and that constituent cells are not failing for one of a several common reasons including membrane dehydration, gas diffusion layer flooding, reactant starvation, and physical damage. Current state-of-the-art monitoring systems are costly and require at least one connection per cell on the stack, which introduces reliability concerns for stacks consisting of hundreds of cells. This thesis presents a novel approach for diagnosing problems in a fuel cell stack that attempts to reduce the cost and complexity of monitoring cells in a stack. The proposed solution modifies the electrochemical impedance spectroscopy (EIS) response of each cell in the stack by connecting an electrical tag in parallel with each cell. This approach allows the EIS response of the entire stack to identify and locate problems in the stack. Capacitors were chosen as tags because they do not interfere with normal stack operation and because they can generate distinct stack EIS responses. An experiment was performed in the Center for Automation Technologies an Systems (CATS) fuel cell laboratory at Rensselaer Polytechnic Institute (RPI) to perform EIS measurements on a single cell with and without capacitor tags to investigate the proposed solution. The EIS data collected from this experiment was used to create a fuel cell model to investigate the proposed solution under ideal conditions. This thesis found that, although the concept shows some promise in simulations, significant obstacles to implementing the proposed solution. Observed EIS response when the capacitor tags were connected did not match the expected EIS response. Constraints on the capacitor tags found by the model impose significant manufacturing challenges to the proposed solution. Further development of the proposed solution is

  7. On gate stack scalability of double-gate negative-capacitance FET with ferroelectric HfO2 for energy efficient sub-0.2 V operation

    Science.gov (United States)

    Jang, Kyungmin; Saraya, Takuya; Kobayashi, Masaharu; Hiramoto, Toshiro

    2018-02-01

    We have investigated the gate stack scalability and energy efficiency of double-gate negative-capacitance FET (DGNCFET) with a CMOS-compatible ferroelectric HfO2 (FE:HfO2). Analytic model-based simulation is conducted to investigate the impacts of ferroelectric characteristic of FE:HfO2 and gate stack thickness on the I on/I off ratio of DGNCFET. DGNCFET has wider design window for the gate stack where higher I on/I off ratio can be achieved than DG classical MOSFET. Under a process-induced constraint with sub-10 nm gate length (L g), FE:HfO2-based DGNCFET still has a design point for high I on/I off ratio. With an optimized gate stack thickness for sub-10 nm L g, FE:HfO2-based DGNCFET has 2.5× higher energy efficiency than DG classical MOSFET even at ultralow operation voltage of sub-0.2 V.

  8. Operational limits and conditions and operating procedures for research reactors. Safety guide

    International Nuclear Information System (INIS)

    2008-01-01

    This publication provides practical guidance on all important aspects of developing, formulating and presenting the operational limits and conditions as well as the operating procedures for research reactors. It covers the concept of operational limits and conditions, their content, and the responsibilities of the operating organization with respect to their establishment, modification, documentation and compliance. The guidance also covers the training of operating personnel on performing periodic testing, established by the operational limits and conditions, and operating procedures

  9. Operational experience at RCD and FCD laboratories during various ventilation conditions

    International Nuclear Information System (INIS)

    Murali, S.; Ashok Kumar, P.; Thanamani, M.; Rath, D.P.; Sapkal, J.A.; Raman, Anand

    2007-01-01

    Radiochemistry and Fuel Chemistry wing of Radiological Laboratory facility has various radio-chemical operations on isotopes of plutonium and trans-plutonium elements, carried out under containment and safe operational conditions. The ventilation provided to the facility is a Once - through system. The ventilation system is designed with separate headers for laboratory and glove box exhausts. There is scheduled periodic shut down of ventilation system for maintenance during non-occupancy hours/week ends. The buildup of natural α - emitters activity due to ventilation shut down, observed to be prevailing on stack air sample filter papers after the ventilation startup, is studied. The paper describes the operational experience gained over a period during ventilation shut down and suggests the course of remedial action for reducing the internal exposure due to build up of natural α - emitters and their progenies. (author)

  10. Operational performance of generator condition monitors

    International Nuclear Information System (INIS)

    Braun, J.M.; Brown, G.

    1990-01-01

    This paper reports on the generator condition monitor (GCM) developed in an attempt to detect overheating inside large turbine generators. As part of a broader study on rotating machinery diagnostics, generator condition monitors were evaluated under field conditions in a 550 MW turbogenerator. Small 100 W resistors coated with insulating paints and varnishes were mounted inside the generator to simulate insulation overheating. The GCM responded very rapidly to an overheating event, typically within two minutes, even for hot spots as small s 10 cm 2 . Similarly the aerosols produced on overheating were found extremely short lived, decaying within two to three minutes after overheating was discontinued. Use of heated ion chambers was found to desensitize the GCM regardless of the nature of the overheated insulation and in some cases would altogether prevent the GCM from reaching the 50% pre-set alarm level commonly used on GCMs

  11. Fuel Cell Stack Testing and Durability in Support of Ion Tiger UAV

    Science.gov (United States)

    2010-06-02

    This report covers efforts by the Hawaii Natural Energy Institute (HNEI) of the University of Hawaii under the ONR-funded Ion Tiger UAV award that included testing of Ion Tiger fuel cell stacks in HNEI’s Hawaii Fuel Cell Test Facility located in Honolulu, Hawaii. Work was focused on steady-state stack characteristics of Protonex fuel cell stacks under various operating conditions. In addition, Hardware-in-the-Loop testing was performed to characterize dynamic

  12. 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...

  13. Operator strategies under varying conditions of workload

    Science.gov (United States)

    Arnegard, Ruth J.

    1991-01-01

    An attempt was made to operationally define and measure strategic behavior in a complex multiple task environment. The Multi-Attribute Task battery was developed to simulate various aspects of flight and consisted of an auditory communication task, monitoring tasks, a tracking tasks, a resource management task which allowed a wide range of responding patterns, and a scheduling window which allowed operators to predict changes in workload. This battery was validated for its sensitivity to strategic behavior, and baseline measures for each individual task were collected. Twenty-four undergraduate and graduate students then performed the battery for four 64 minute sessions which took place over a period of 2 days. Each subject performed the task battery under four levels of workload, which were presented for equal lengths of time during all four sessions. Results indicated that in general, performance improves as a function of experience with the battery, but that performance decreased as workload level increased. The data also showed that subjects developed strategies for responding to the resource management task which allowed them to manage the high workload levels more efficiently. This particular strategy developed over time but was also associated with errors of complacency. These results are presented along with implications for the aviation field and areas of future research.

  14. Post-test characterization of a solid oxide fuel cell stack operated for more than 30,000 hours: The cell

    Science.gov (United States)

    Menzler, Norbert H.; Sebold, Doris; Guillon, Olivier

    2018-01-01

    A four-layer solid oxide fuel cell stack with planar anode-supported cells was operated galvanostatically at 700 °C and 0.5Acm-2 for nearly 35,000 h. One of the four planes started to degrade more rapidly after ∼28,000 h and finally more progressively after ∼33,000 h. The stack was then shut down and a post-test analysis was carefully performed. The cell was characterized with respect to cathodic impurities and clarification of the reason(s) for failure. Wet chemical analysis revealed very low chromium incorporation into the cathode. However, SEM and TEM observations on polished and fractured surfaces showed catastrophic failure in the degraded layer. The cathode-barrier-electrolyte cell layer system delaminated from the entire cell over large areas. The source of delamination was the formation of a porous, sponge-like secondary phase consisting of zirconia, yttria and manganese (oxide). Large secondary phase islands grew from the electrolyte-anode interface towards the anode and cracked the bonding between both layers. The manganese originated from the contact or protection layers used on the air side. This stack result shows that volatile species - in this case manganese - should be avoided, especially when long-term applications are envisaged.

  15. 47 CFR 18.111 - General operating conditions.

    Science.gov (United States)

    2010-10-01

    ... EQUIPMENT General Information § 18.111 General operating conditions. (a) Persons operating ISM equipment... equipment otherwise complies with the rules in this part, the operator of ISM equipment that causes harmful... interference to an authorized radio station or a radiocommunication device operating in an ISM frequency band...

  16. Infant Operant Conditioning and Its Implications for Early Intervention.

    Science.gov (United States)

    Lancioni, Giullo E.

    1980-01-01

    In this article infant operant conditioning studies are grouped according to distinct procedures: free operant; discrete trial with one discriminative stimulus; discrete trial with two or more discriminative stimuli; controlled operant with two or more discriminative stimuli; and unrestricted operant with two or more discriminative stimuli.…

  17. The Direct FuelCell™ stack engineering

    Science.gov (United States)

    Doyon, J.; Farooque, M.; Maru, H.

    FuelCell Energy (FCE) has developed power plants in the size range of 300 kW to 3 MW for distributed power generation. Field-testing of the sub-megawatt plants is underway. The FCE power plants are based on its Direct FuelCell™ (DFC) technology. This is so named because of its ability to generate electricity directly from a hydrocarbon fuel, such as natural gas, by reforming it inside the fuel cell stack itself. All FCE products use identical 8000 cm 2 cell design, approximately 350-400 cells per stack, external gas manifolds, and similar stack compression systems. The difference lies in the packaging of the stacks inside the stack module. The sub-megawatt system stack module contains a single horizontal stack whereas the MW-class stack module houses four identical vertical stacks. The commonality of the design, internal reforming features, and atmospheric operation simplify the system design, reduce cost, improve efficiency, increase reliability and maintainability. The product building-block stack design has been advanced through three full-size stack operations at company's headquarters in Danbury, CT. The initial proof-of-concept of the full-size stack design was verified in 1999, followed by a 1.5 year of endurance verification in 2000-2001, and currently a value-engineered stack version is in operation. This paper discusses the design features, important engineering solutions implemented, and test results of FCE's full-size DFC stacks.

  18. Algebraic stacks

    Indian Academy of Sciences (India)

    truct the 'moduli stack', that captures all the information that we would like in a fine moduli space. ..... the fine moduli space), it has the property that for any family W of vector bundles (i.e. W is a vector bundle over B ...... the etale topology is finer: V is a 'small enough open subset' because the square root can be defined on it.

  19. Gender classification under extended operating conditions

    Science.gov (United States)

    Rude, Howard N.; Rizki, Mateen

    2014-06-01

    Gender classification is a critical component of a robust image security system. Many techniques exist to perform gender classification using facial features. In contrast, this paper explores gender classification using body features extracted from clothed subjects. Several of the most effective types of features for gender classification identified in literature were implemented and applied to the newly developed Seasonal Weather And Gender (SWAG) dataset. SWAG contains video clips of approximately 2000 samples of human subjects captured over a period of several months. The subjects are wearing casual business attire and outer garments appropriate for the specific weather conditions observed in the Midwest. The results from a series of experiments are presented that compare the classification accuracy of systems that incorporate various types and combinations of features applied to multiple looks at subjects at different image resolutions to determine a baseline performance for gender classification.

  20. Forced Air-Breathing PEMFC Stacks

    Directory of Open Access Journals (Sweden)

    K. S. Dhathathreyan

    2012-01-01

    Full Text Available Air-breathing fuel cells have a great potential as power sources for various electronic devices. They differ from conventional fuel cells in which the cells take up oxygen from ambient air by active or passive methods. The air flow occurs through the channels due to concentration and temperature gradient between the cell and the ambient conditions. However developing a stack is very difficult as the individual cell performance may not be uniform. In order to make such a system more realistic, an open-cathode forced air-breathing stacks were developed by making appropriate channel dimensions for the air flow for uniform performance in a stack. At CFCT-ARCI (Centre for Fuel Cell Technology-ARC International we have developed forced air-breathing fuel cell stacks with varying capacity ranging from 50 watts to 1500 watts. The performance of the stack was analysed based on the air flow, humidity, stability, and so forth, The major advantage of the system is the reduced number of bipolar plates and thereby reduction in volume and weight. However, the thermal management is a challenge due to the non-availability of sufficient air flow to remove the heat from the system during continuous operation. These results will be discussed in this paper.

  1. Improved solid oxide fuel cell stacks: Power density, durability and modularity. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Lund Frandsen, H.; Kiebach, W.R.; Hoeegh, J. (Technical Univ. of Denmark. Risoe National Lab. for Sustainable Energy, Roskilde (Denmark)) (and others)

    2010-10-15

    This report presents the work performed within the project PSO2009-1-10207 during the period from 01-04-2009 - 31-06-2010. The report is divided into three parts covering the three work packages: Stack components; Stacks and durability; and Large SOFC systems: modularity and scalability. The project contains 38 milestones and all milestones in the project have been either fully or partly fulfilled. Two major achievements within this project concern the robustness towards dynamic operations and implementation of cells with more active cathodes: Within this project tools to evaluate and test SOFC stacks with respect to robustness during dynamic operations has been developed. From stack tests performed under dynamic conditions it was observed that the effect on degradation and failure seemed to be very little. The thermo-mechanical models developed in this project in combination with the dynamic stack model was used in combination to understand why. The results clearly showed that the hardest stress field applied to the cells arises from the steady state operating point rather than from the dynamic conditions. This is a very promising result concerning the fact that especially small CHP units in a commercial system will experience dynamic conditions from load cycling and thermal cycling. A new type of cell with a more active cathode has been formulated and introduced into the TOFC stacks in this project. The aim was to improve the effect of the stack by 25 %. However, compared to a standard stack with the ''old'' cells, the stack effect was increased by 44% - from a cross flow stack with standard 2G cells to a cross flow stack with 2.5G cells. The new type of cells also show an excellent stability towards moisture in the cathode feed, and a stack with 2.5G cells has been tested for 12.000 hrs with a degradation rate of 30 mOMEGAcm2/1000 hr. (Author)

  2. Correlation of Grain Size, Stacking Fault Energy, and Texture in Cu-Al Alloys Deformed under Simulated Rolling Conditions

    Directory of Open Access Journals (Sweden)

    Ehab A. El-Danaf

    2015-01-01

    Full Text Available The effect of grain size and stacking fault energy (SFE on the strain hardening rate behavior under plane strain compression (PSC is investigated for pure Cu and binary Cu-Al alloys containing 1, 2, 4.7, and 7 wt. % Al. The alloys studied have a wide range of SFE from a low SFE of 4.5 mJm−2 for Cu-7Al to a medium SFE of 78 mJm−2 for pure Cu. A series of PSC tests have been conducted on these alloys for three average grain sizes of ~15, 70, and 250 μm. Strain hardening rate curves were obtained and a criterion relating twinning stress to grain size is established. It is concluded that the stress required for twinning initiation decreases with increasing grain size. Low values of SFE have an indirect influence on twinning stress by increasing the strain hardening rate which is reflected in building up the critical dislocation density needed to initiate mechanical twinning. A study on the effect of grain size on the intensity of the brass texture component for the low SFE alloys has revealed the reduction of the orientation density of that component with increasing grain size.

  3. Modeling and Simulation of the ARES UPPER STAGE Transportation, Lifting, Stacking and Mating Operations Within the Vehicle Assembly Building at KSC

    Science.gov (United States)

    Kromis, Phillip A.

    2010-01-01

    This viewgraph presentation describes the modeling and simulation of the Ares Upper Stage Transportation, lifting, stacking, and mating operations within the Vehicle Assembly Building (VAB) at Kennedy Space Center (KSC). An aerial view of KSC Launch Shuttle Complex, two views of the Delmia process control layout, and an upper stage move subroutine and breakdown are shown. An overhead image of the VAB and the turning basin along with the Pegasus barge at the turning basin are also shown. This viewgraph presentation also shows the actual design and the removal of the mid-section spring tensioners, the removal of the AFT rear and forward tensioners tie downs, and removing the AFT hold down post and mount. US leaving the Pegasus Barge, the upper stage arriving at transfer aisle, upper stage receiving/inspection in transfer aisle, and an overhead view of upper stage receiving/inspection in transfer aisle are depicted. Five views of the actual connection of the cabling to the upper stage aft lifting hardware are shown. The upper stage transporter forward connector, two views of the rotation horizontal to vertical, the disconnection of the rear bolt ring cabling, the lowering of the upper stage to the inspection stand, disconnection of the rear bolt ring from the upper stage, the lifting of the upper stage and inspection of AFT fange, and the transfer of upper stage in an integrated stack are shown. Six views of the mating of the upper stage to the first stage are depicted. The preparation, inspection, and removal of the forward dome are shown. The upper stage mated on the integrated stack and crawler is also shown. This presentation concludes with A Rapid Upper Limb Assessment (RULA) utilizing male and female models for assessing risk factors to the upper extremities of human beings in an actual physical environment.

  4. 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}.

  5. 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.

  6. The Gerbil Jar: A Basic Home Experience in Operant Conditioning.

    Science.gov (United States)

    Plant, L.

    1980-01-01

    Explains how a teaching method such as allowing students to raise gerbils at home can encourage students to gain experience with the fundamental techniques of operant conditioning which are otherwise generally unavailable to students in large introductory psychology courses. (DB)

  7. Strategies for operation of containment related ESFs in managing activity release to the environment during accident conditions

    International Nuclear Information System (INIS)

    Bhawal, R.N.; Bajaj, S.S.

    1998-01-01

    In Indian PHWR design, a double containment concept with passive vapour suppression pool (to limit peak pressure) system has been adopted. In addition to it, various Engineered Safety Features (ESFs) have been incorporated to limit the release of radioactivity to the environment. They are: Reactor building emergency coolers for cooling which results in fast reduction of overpressure; Primary Containment Filtration and Pump Back System (PCFPBS) for reduction in iodine concentration inside RB atmosphere during post LOCA period; and, Primary Containment Controlled Discharge System (PCCDS) for the rapid reduction of over-pressure tail. Due to operation of secondary containment purge system, which maintain negative pressure in the annulus, the ground level release is negligibly small. However, if non- availability of negative pressure in secondary containment space is assumed, then operation of PCFPBS and PCCDS system reduces the ground level release significantly. In this situation, depending upon time of operation of the PCFPBS, it can effectively reduce the iodine release, both in stack level and ground level by trapping it in charcoal filters. It is seen that delay time of PCFPBS operation in conjunction with prevailing weather condition can be manipulated to reduce the effect of stack level release of iodine. In this paper the containment related ESFs used in Indian PHWR is discussed in brief and the effectiveness of operator actions and management strategies in actuation of the ESFs in reducing the activity release to environment (during postulated accident conditions) will be brought out. (author)

  8. Virasoro conditions, vertex operators, and string dynamics in curved space

    International Nuclear Information System (INIS)

    Jain, S.; Mandal, G.; Wadia, S.R.

    1987-01-01

    We present the perturbatively renormalized expression of a scalar vertex operator for strings in a background metric and dilaton field. The equations of motion for the background fields and the wave equation for the vertex function emerge upon imposing Virasoro conditions on the vertex operator

  9. Transient pressure measurements at part load operating condition of ...

    Indian Academy of Sciences (India)

    Hydraulic turbines are operating at part load conditions depending on availability of hydraulic energy or to meet the grid requirements. The turbine experiences ... The present paper focuses on the investigation of a high head model Francis turbine operating at 50% load.Pressure ... University of Technology, Lulea ., Sweden ...

  10. Operant Conditioning in Older Adults with Alzheimer's Disease

    Science.gov (United States)

    Spira, Adam P.; Edelstein, Barry A.

    2007-01-01

    Behavioral interventions based on operant principles are commonly attempted to manage agitation in older adults with dementia. The extent to which operant conditioning can occur in persons with particular dementias, however, is unclear. The present study involved use of a button-pressing task to evaluate the sensitivity of the responding of older…

  11. Development and durability of SOFC stacks

    Energy Technology Data Exchange (ETDEWEB)

    Beeaff, D.; Dinesen, A.R.; Mikkelsen, Lars; Nielsen, Karsten A.; Solvang, M.; Hendriksen, Peter V.

    2004-12-01

    The present project is a part of the Danish SOFC programme, which has the overall aim of establishing a Danish production of SOFC - cells, stacks and systems for economical and environmentally friendly power production. The aim of the present project was to develop and demonstrate (on a small scale, few cells, few thousand hours) a durable, thermally cyclable stack with high performance at 750 deg. C. Good progress towards this target has been made and demonstrated at the level of stack-elements (one cell between two interconnects) or small stacks (3 5 cells). Three different stacks or stack-elements have been operated for periods exceeding 3000 hr. The work has covered development of stack-components (seals, interconnects, coatings, contact layers), establishment of procedures for stack assembly and initiation, and detailed electrical characterisation with the aims of identifying performance limiting factors as well as long term durability. Further, post test investigations have been carried out to identify possible degradation mechanisms. (BA)

  12. 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

  13. SRS reactor stack plume marking tests

    International Nuclear Information System (INIS)

    Petry, S.F.

    1992-03-01

    Tests performed in 105-K in 1987 and 1988 demonstrated that the stack plume can successfully be made visible (i.e., marked) by introducing smoke into the stack breech. The ultimate objective of these tests is to provide a means during an emergency evacuation so that an evacuee can readily identify the stack plume and evacuate in the opposite direction, thus minimizing the potential of severe radiation exposure. The EPA has also requested DOE to arrange for more tests to settle a technical question involving the correct calculation of stack downwash. New test canisters were received in 1988 designed to produce more smoke per unit time; however, these canisters have not been evaluated, because normal ventilation conditions have not been reestablished in K Area. Meanwhile, both the authorization and procedure to conduct the tests have expired. The tests can be performed during normal reactor operation. It is recommended that appropriate authorization and procedure approval be obtained to resume testing after K Area restart

  14. A novelty detection diagnostic methodology for gearboxes operating under fluctuating operating conditions using probabilistic techniques

    Science.gov (United States)

    Schmidt, S.; Heyns, P. S.; de Villiers, J. P.

    2018-02-01

    In this paper, a fault diagnostic methodology is developed which is able to detect, locate and trend gear faults under fluctuating operating conditions when only vibration data from a single transducer, measured on a healthy gearbox are available. A two-phase feature extraction and modelling process is proposed to infer the operating condition and based on the operating condition, to detect changes in the machine condition. Information from optimised machine and operating condition hidden Markov models are statistically combined to generate a discrepancy signal which is post-processed to infer the condition of the gearbox. The discrepancy signal is processed and combined with statistical methods for automatic fault detection and localisation and to perform fault trending over time. The proposed methodology is validated on experimental data and a tacholess order tracking methodology is used to enhance the cost-effectiveness of the diagnostic methodology.

  15. Equivalent Electrical Circuits of Thermoelectric Generators under Different Operating Conditions

    Directory of Open Access Journals (Sweden)

    Saima Siouane

    2017-03-01

    Full Text Available Energy harvesting has become a promising and alternative solution to conventional energy generation patterns to overcome the problem of supplying autonomous electrical systems. More particularly, thermal energy harvesting technologies have drawn a major interest in both research and industry. Thermoelectric Generators (TEGs can be used in two different operating conditions, under constant temperature gradient or constant heat flow. The commonly used TEG electrical model, based on a voltage source in series with an electrical resistance, shows its limitations especially under constant heat flow conditions. Here, the analytical electrical modeling, taking into consideration the internal and contact thermal resistances of a TEG under constant temperature gradient and constant heat flow conditions, is first given. To give further insight into the electrical behavior of a TEG module in different operating conditions, we propose a new and original way of emulating the above analytical expressions with usual electronics components (voltage source, resistors, diode, whose values are determined with the TEG’s parameters. Note that such a TEG emulation is particularly suited when designing the electronic circuitry commonly associated to the TEG, to realize both Maximum Power Point Tracking and output voltage regulation. First, the proposed equivalent electrical circuits are validated through simulation with a SPICE environment in static operating conditions using only one value of either temperature gradient or heat flow. Then, they are also analyzed in dynamic operating conditions where both temperature gradient and heat flow are considered as time-varying functions.

  16. Method of operating a molten carbonate fuel cell, a fuel cell, a fuel cell stack and an apparatus provided therewith

    NARCIS (Netherlands)

    Hemmes, K.; Dijkema, G.P.J.

    1998-01-01

    A method of operating a molten carbonate fuel cell having an anode and a cathode and in between a matrix comprising molten carbonate. Carbon dioxide is introduced into the matrix at a distance from the cathode. This greatly reduces the cathode's deterioration and in the system design increases the

  17. Operational limits and conditions for nuclear power plants

    International Nuclear Information System (INIS)

    1979-01-01

    This Safety Guide was prepared as part of the Agency's programme, referred to as the NUSS programme, for establishing Codes of Practice and Safety Guides relating to nuclear power plants. It covers the concept of operational limits and conditions, their content as applicable to various types of thermal reactors, and the responsibilities of the operating organization regarding their establishment, modification, compliance and documentation. The principles of the operational limits and conditions are established in section 3 of the Agency's Code of Practice on Safety in Nuclear Power Plant Operation, including Commissioning and Decommissioning (IAEA Safety Series No. 50-C-O), which this present Safety Guide supplements. In order to present all pertinent information in this Guide, the provisions of section 3 of the Code are repeated

  18. 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.

  19. 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.

  20. 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.

  1. Solid Oxide Fuel Cell Stack Diagnostics

    DEFF Research Database (Denmark)

    Mosbæk, Rasmus Rode; Barfod, Rasmus Gottrup

    . An operating stack is subject to compositional gradients in the gaseous reactant streams, and temperature gradients across each cell and across the stack, which complicates detailed analysis. Several experimental stacks from Topsoe Fuel Cell A/S were characterized using Electrochemical Impedance Spectroscopy...... (EIS). The stack measurement geometry was optimized for EIS by careful selection of the placement of current feeds and voltage probes in order to minimize measurement errors. It was demonstrated that with the improved placement of current feeds and voltage probes it is possible to separate the loss...... in the hydrogen fuel gas supplied to the stack. EIS was used to examine the long-term behavior and monitor the evolution of the impedance of each of the repeating units and the whole stack. The observed impedance was analyzed in detail for one of the repeating units and the whole stack and the losses reported...

  2. Electrically Conductive and Protective Coating for Planar SOFC Stacks

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jung-Pyung; Stevenson, Jeffry W.

    2017-12-04

    Ferritic stainless steels are preferred interconnect materials for intermediate temperature SOFCs because of their resistance to oxidation, high formability and low cost. However, their protective oxide layer produces Cr-containing volatile species at SOFC operating temperatures and conditions, which can cause cathode poisoning. Electrically conducting spinel coatings have been developed to prevent cathode poisoning and to maintain an electrically conductive pathway through SOFC stacks. However, this coating is not compatible with the formation of stable, hermetic seals between the interconnect frame component and the ceramic cell. Thus, a new aluminizing process has been developed by PNNL to enable durable sealing, prevent Cr evaporation, and maintain electrical insulation between stack repeat units. Hence, two different types of coating need to have stable operation of SOFC stacks. This paper will focus on the electrically conductive coating process. Moreover, an advanced coating process, compatible with a non-electrically conductive coating will be

  3. 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.

  4. Operational limit conditions of the spur gears in lubricated modes

    Science.gov (United States)

    Benilha, S.; Belarifi, F.

    2018-01-01

    The calculation of the gear teeth resistance, shows the using of a certain number of coefficients determined experimentally and which are accepted by the various international standards. However, this kind of calculation determines the gears by excess material and does not support the tribological parameters of operation. We propose in this work the support of these parameters, to determine the limit operation conditions of the spur gears, using the equivalent geometry. This is represented by two cylinders, which geometrically models of the contact between two teeth of a gear and whose lubrication is generally in mixed lubrication mode. The concept of Mc cool is used to determine the distribution of the load and the friction force, which are distributed in liquid (elastohydrodynamic) and solid domains and interact with each other. The phenomenon of interaction between the two domains is used, to predict the tribological limit conditions of operation. The proposed model is based on the resolution of elastohydrodynamic equations for the determination of load and friction as well as the deduction of mixed friction by tracing the Stribeck curve. This is calculated by the model of the decomposition of the patterns profile of rough surfaces in contacts. The results of non-dimensional calculations allow us to deduce the boundary conditions and can be adapted for any type of gear pair defined according to pre-established operating conditions.

  5. Analysis of VVER-1000 main circulation pump condition under operation

    International Nuclear Information System (INIS)

    Leskin, S.T.; Slobodchuk, V.I.; Shelegov, A.S.

    2016-01-01

    Authors present a method and algorithms for detecting the abnormal condition of the main circulation pumps based on their on-power testing results. The efficiency of these algorithms has been demonstrated by their application for detecting abnormalities in the main circulation pump operation at the Russian nuclear power plants [ru

  6. Transient pressure measurements at part load operating condition of ...

    Indian Academy of Sciences (India)

    Rahul Goyal

    hydraulic energy or demand of market. The turbine expe- riences unstable flow conditions during .... gate the pressure loading inside the turbine at a similar load. No measurements have been reported in the .... speed factor (nED) and discharge factor (qED) are 0.18 and. 0.15, respectively. The operating point selected for ...

  7. 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…

  8. Teleportation protocol with non-ideal conditional local operations

    International Nuclear Information System (INIS)

    Di Franco, C.; Ballester, D.

    2010-01-01

    We analyze teleportation protocol when some of receiver's conditional operations are more reliable than others and a non-maximally entangled channel is shared by the two parts. We show that the average fidelity of teleportation can be maximized by choosing properly the basis in which the sender performs her two-qubit measurement.

  9. 14 CFR 125.221 - Icing conditions: Operating limitations.

    Science.gov (United States)

    2010-01-01

    ... appendix C of this part or those for transport category airplane type certification, no pilot may fly— (1... pilot may fly an airplane into known or forecast severe icing conditions. (e) If current weather reports... CERTIFICATION AND OPERATIONS: AIRPLANES HAVING A SEATING CAPACITY OF 20 OR MORE PASSENGERS OR A MAXIMUM PAYLOAD...

  10. 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. Copyright © 2011 Elsevier B.V. All rights reserved.

  11. Updating Coverage of Operant Conditioning in Introductory Psychology.

    Science.gov (United States)

    Buskist, William; Miller, Erin; Ecott, Cheryl; Critchfield, Thomas S.

    1999-01-01

    Offers an example of determining what the experts of psychology deem as essential concepts in their subfield by investigating the current principles in operant conditioning through surveys of the board of editors of the "Journal of the Experimental Analysis of Behavior." Recommends concepts that are appropriate for up-to-date coverage of operant…

  12. 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...

  13. Standoff Stack Emissions Monitoring Using Short Range Lidar

    Science.gov (United States)

    Gravel, Jean-Francois Y.; Babin, Francois; Allard, Martin

    2016-06-01

    There are well documented methods for stack emissions monitoring. These are all based on stack sampling through sampling ports in well defined conditions. Once sampled, the molecules are quantified in instruments that often use optical techniques. Unfortunately sampling ports are not found on all stacks/ducts or the use of the sampling ports cannot be planned efficiently because of operational constraints or the emissions monitoring equipment cannot be driven to a remote stack/duct. Emissions monitoring using many of the same optical techniques, but at a standoff distance, through the atmosphere, using short range high spatial resolution lidar techniques was thus attempted. Standoff absorption and Raman will be discussed and results from a field campaign will be presented along with short descriptions of the apparatus. In the first phase of these tests, the molecules that were targeted were NO and O2. Spatially resolved optical measurements allow for standoff identification and quantification of molecules, much like the standardized methods, except for the fact that it is not done in the stack, but in the plume formed by the emissions from the stack. The pros and cons will also be discussed, and in particular the problem of mass emission estimates that require the knowledge of the flow rate and the distribution of molecular concentration in the plane of measurement.

  14. Standoff Stack Emissions Monitoring Using Short Range Lidar

    Directory of Open Access Journals (Sweden)

    Gravel Jean-Francois Y.

    2016-01-01

    Full Text Available There are well documented methods for stack emissions monitoring. These are all based on stack sampling through sampling ports in well defined conditions. Once sampled, the molecules are quantified in instruments that often use optical techniques. Unfortunately sampling ports are not found on all stacks/ducts or the use of the sampling ports cannot be planned efficiently because of operational constraints or the emissions monitoring equipment cannot be driven to a remote stack/duct. Emissions monitoring using many of the same optical techniques, but at a standoff distance, through the atmosphere, using short range high spatial resolution lidar techniques was thus attempted. Standoff absorption and Raman will be discussed and results from a field campaign will be presented along with short descriptions of the apparatus. In the first phase of these tests, the molecules that were targeted were NO and O2. Spatially resolved optical measurements allow for standoff identification and quantification of molecules, much like the standardized methods, except for the fact that it is not done in the stack, but in the plume formed by the emissions from the stack. The pros and cons will also be discussed, and in particular the problem of mass emission estimates that require the knowledge of the flow rate and the distribution of molecular concentration in the plane of measurement.

  15. 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.

  16. Operant conditioning of reciprocal inhibition in rat soleus muscle.

    Science.gov (United States)

    Chen, Xiang Yang; Chen, Lu; Chen, Yi; Wolpaw, Jonathan R

    2006-10-01

    Operant conditioning of the H-reflex, the electrical analog of the spinal stretch reflex (SSR), induces activity-dependent plasticity in the spinal cord and might be used to improve locomotion after spinal cord injury. To further assess the potential clinical significance of spinal reflex conditioning, this study asks whether another well-defined spinal reflex pathway, the disynaptic pathway underlying reciprocal inhibition (RI), can also be operantly conditioned. Sprague-Dawley rats were implanted with electromyographic (EMG) electrodes in right soleus (SOL) and tibialis anterior (TA) muscles and a stimulating cuff on the common peroneal (CP) nerve. When background EMG in both muscles remained in defined ranges, CP stimulation elicited the TA H-reflex and SOL RI. After collection of control data for 20 days, each rat was exposed for 50 days to up-conditioning (RIup mode) or down-conditioning (RIdown mode) in which food reward occurred if SOL RI evoked by CP stimulation was more (RIup mode) or less (RIdown mode) than a criterion. TA and SOL background EMG and TA M response remained stable. In every rat, RI conditioning was successful (i.e., change > or =20% in the correct direction). In the RIup rats, final SOL RI averaged 171+/- 28% (mean +/- SE) of control, and final TA H-reflex averaged 114 +/- 14%. In the RIdown rats, final SOL RI averaged 37 +/- 13% of control, and final TA H-reflex averaged 60 +/- 18%. Final SOL RI and TA H-reflex sizes were significantly correlated. Thus like the SSR and the H-reflex, RI can be operantly conditioned; and conditioning one reflex can affect another reflex as well.

  17. Ionization beam profile monitor for operation under hard environmental conditions

    International Nuclear Information System (INIS)

    Teterev, Yu.G.; Kaminski, G.; Phi Thanh Huong; Kaminski, G.; Kozik, E.

    2010-01-01

    The design and the performance of the Ionization Beam Profile Monitor (IBPM) operating on the residual gas ionization principle are described. The main advantage of the constructed device is the non-contact measuring method. Operating under hard environmental conditions it delivers the information about the primary beam position, profile and intensity in 'on-line' regime. It was found out that the device is capable to operate in vacuum in the range of 10 -6 /10 -3 mbar without the loss of the resolution power at the beam current as low as a few nA. The IBPM is prospective for beam profile monitoring due to long time. Emergency situations do not lead to decrease of its operability.

  18. 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...

  19. Experimental 1 kW 20 cell PEFC stack

    Energy Technology Data Exchange (ETDEWEB)

    Buechi, F.N.; Marmy, C.A.; Scherer, G.G. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Ruge, M. [Swiss Federal Inst. of Technology (ETH), Zuerich (Switzerland)

    1999-08-01

    A 20-cell PEFC stack was designed and built. Resin impregnated graphite was used as bipolar plate material. The air cooling of the stack was optimized by introducing high surface structures into the open space of the cooling plates. At {eta} (H{sub 2} LHV) = 0.5 a power of 880 W was obtained under conditions of low gas-pressures of 1.15 bar{sub a}. The auxiliary power for process air supply and cooling at 880 W power is less than 7% of the power output, indicating that the described system may be operated at a high efficiency. (author) 5 figs., 2 refs.

  20. 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.

  1. Calculations of stresses in GCFR cladding under normal operating conditions

    International Nuclear Information System (INIS)

    Liu, Y.Y.; Hsieh, T.C.; Billone, M.C.

    1979-11-01

    A modified version of the LIFE-III code, LIFE-GCFR, and classical stress-analysis techniques have been used to calculate the stresses in the GCFR cladding under normal reactor operating conditions. Several types of loadings on the cladding that occur during normal operation have been considered. These include fuel-cladding mechanical interaction, thermal stresses induced by radial and axial temperature gradients, and swelling gradient-induced stresses. The combined and individual effects of these loadings, as well as the effect of creep on cladding stresses, have been assessed

  2. Fuel conditioning facility electrorefiner cadmium vapor trap operation

    International Nuclear Information System (INIS)

    Vaden, D. E.

    1998-01-01

    Processing sodium-bonded spent nuclear fuel at the Fuel Conditioning Facility at Argonne National Laboratory-West involves an electrometallurgical process employing a molten LiCl-KCl salt covering a pool of molten cadmium. Previous research has shown that the cadmium dissolves in the salt as a gas, diffuses through the salt layer and vaporizes at the salt surface. This cadmium vapor condenses on cool surfaces, causing equipment operation and handling problems. Using a cadmium vapor trap to condense the cadmium vapors and reflux them back to the electrorefiner has mitigated equipment problems and improved electrorefiner operations

  3. Optimization of manifold design for 1 kW-class flat-tubular solid oxide fuel cell stack operating on reformed natural gas

    Science.gov (United States)

    Rashid, Kashif; Dong, Sang Keun; Khan, Rashid Ali; Park, Seung Hwan

    2016-09-01

    This study focuses on optimizing the manifold design for a 1 kW-class flat-tubular solid oxide fuel cell stack by performing extensive three-dimensional numerical simulations on numerous manifold designs. The stack flow uniformity and the standard flow deviation indexes are implemented to characterize the flow distributions in the stack and among the channels of FT-SOFC's, respectively. The results of the CFD calculations demonstrate that the remodeled manifold without diffuser inlets and 6 mm diffuser front is the best among investigated designs with uniformity index of 0.996 and maximum standard flow deviation of 0.423%. To understand the effect of manifold design on the performance of stack, both generic and developed manifold designs are investigated by applying electrochemical and internal reforming reactions modeling. The simulation results of the stack with generic manifold are validated using experimental data and then validated models are adopted to simulate the stack with the developed manifold design. The results reveal that the stack with developed manifold design achieves more uniform distribution of species, temperature, and current density with comparatively lower system pressure drop. In addition, the results also showed ∼8% increase in the maximum output power due to the implementation of uniform fuel velocity distributions in the cells.

  4. Resistive switching mechanism of ZnO/ZrO2-stacked resistive random access memory device annealed at 300 °C by sol-gel method with forming-free operation

    Science.gov (United States)

    Jian, Wen-Yi; You, Hsin-Chiang; Wu, Cheng-Yen

    2018-01-01

    In this work, we used a sol-gel process to fabricate a ZnO-ZrO2-stacked resistive switching random access memory (ReRAM) device and investigated its switching mechanism. The Gibbs free energy in ZnO, which is higher than that in ZrO2, facilitates the oxidation and reduction reactions of filaments in the ZnO layer. The current-voltage (I-V) characteristics of the device revealed a forming-free operation because of nonlattice oxygen in the oxide layer. In addition, the device can operate under bipolar or unipolar conditions with a reset voltage of 0 to ±2 V, indicating that in this device, Joule heating dominates at reset and the electric field dominates in the set process. Furthermore, the characteristics reveal why the fabricated device exhibits a greater discrete distribution phenomenon for the set voltage than for the reset voltage. These results will enable the fabrication of future ReRAM devices with double-layer oxide structures with improved characteristics.

  5. How Much of Language Acquisition Does Operant Conditioning Explain?

    Directory of Open Access Journals (Sweden)

    Christopher B. Sturdy

    2017-10-01

    Full Text Available Since the 1950s, when Chomsky argued that Skinner’s arguments could not explain syntactic acquisition, psychologists have generally avoided explicitly invoking operant or instrumental conditioning as a learning mechanism for language among human children. In this article, we argue that this is a mistake. We focus on research that has been done on language learning in human infants and toddlers in order to illustrate our points. Researchers have ended up inventing learning mechanisms that, in actual practice, not only resemble but also in fact are examples of operant conditioning (OC by any other name they select. We argue that language acquisition researchers should proceed by first ruling out OC before invoking alternative learning mechanisms. While it is possible that OC cannot explain all of the language acquisition, simple learning mechanisms that work across species may have some explanatory power in children’s language learning.

  6. How Much of Language Acquisition Does Operant Conditioning Explain?

    Science.gov (United States)

    Sturdy, Christopher B.; Nicoladis, Elena

    2017-01-01

    Since the 1950s, when Chomsky argued that Skinner’s arguments could not explain syntactic acquisition, psychologists have generally avoided explicitly invoking operant or instrumental conditioning as a learning mechanism for language among human children. In this article, we argue that this is a mistake. We focus on research that has been done on language learning in human infants and toddlers in order to illustrate our points. Researchers have ended up inventing learning mechanisms that, in actual practice, not only resemble but also in fact are examples of operant conditioning (OC) by any other name they select. We argue that language acquisition researchers should proceed by first ruling out OC before invoking alternative learning mechanisms. While it is possible that OC cannot explain all of the language acquisition, simple learning mechanisms that work across species may have some explanatory power in children’s language learning. PMID:29163295

  7. 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.

  8. How Much of Language Acquisition Does Operant Conditioning Explain?

    Science.gov (United States)

    Sturdy, Christopher B; Nicoladis, Elena

    2017-01-01

    Since the 1950s, when Chomsky argued that Skinner's arguments could not explain syntactic acquisition, psychologists have generally avoided explicitly invoking operant or instrumental conditioning as a learning mechanism for language among human children. In this article, we argue that this is a mistake. We focus on research that has been done on language learning in human infants and toddlers in order to illustrate our points. Researchers have ended up inventing learning mechanisms that, in actual practice, not only resemble but also in fact are examples of operant conditioning (OC) by any other name they select. We argue that language acquisition researchers should proceed by first ruling out OC before invoking alternative learning mechanisms. While it is possible that OC cannot explain all of the language acquisition, simple learning mechanisms that work across species may have some explanatory power in children's language learning.

  9. 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...

  10. How Much of Language Acquisition Does Operant Conditioning Explain?

    OpenAIRE

    Sturdy, Christopher B.; Nicoladis, Elena

    2017-01-01

    Since the 1950s, when Chomsky argued that Skinner’s arguments could not explain syntactic acquisition, psychologists have generally avoided explicitly invoking operant or instrumental conditioning as a learning mechanism for language among human children. In this article, we argue that this is a mistake. We focus on research that has been done on language learning in human infants and toddlers in order to illustrate our points. Researchers have ended up inventing learning mechanisms that, in ...

  11. 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.

  12. Effect of flow parameters on flare stack generator noise

    International Nuclear Information System (INIS)

    Dinn, T.S.

    1998-01-01

    The SoundPLAN Computer Noise Model was used to determine the general effect of flare noise in a community adjacent to a petrochemical plant. Tests were conducted to determine the effect of process flow conditions and the pulsating flame on the flare stack generator noise from both a refinery flare and process flare. Flaring under normal plant operations, the flaring of fuel gas and the flaring of hydrogen were the three conditions that were tested. It was shown that the steam flow rate was the determining factor in the flare stack generated noise. Variations in the water seal level in the flare line surge tank increased or decreased the gas flowrate, which resulted in a pulsating flame. The period and amplitude of the pulsating noise from the flare stacks was determined by measuring several parameters. Flare stack noise oscillations were found to be greater for the process flare than for the refinery flare stack. It was suggested that minimizing the amount of steam fed to the flare and improving the burner design would minimize noise. 2 tabs., 6 figs

  13. 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.

  14. Analysis of operating conditions of the voltage transformer

    Directory of Open Access Journals (Sweden)

    Fastiy G. P.

    2017-12-01

    Full Text Available In electrical networks, constant monitoring of the electrical equipment operation is necessary. To accomplish this task, current transformers and voltage transformers (VT are used, on which the accuracy of electrical measurements, electricity metering, and the reliability of the emergency control system depend. The results of the analysis of the conditions for forming the magnetization of a voltage transformer in the mode with unilateral connection of overhead transmission lines, as well as variants of violations in the 110 kV network that may exist for a relatively long time have been presented. It should be noted that the considered network has its own peculiarities: the overhead transmission lines connected in series have a significant length and a low level of load, which may be a condition for the appearance of a transmission lines capacitive effect (the Ferranti effect, the latter can cause overvoltage. Overvoltage occurs when the operating modes are temporary in terms of operation, adverse combinations of network parameters take place, and can continue until the circuit and network modes change. Most often they appear in asymmetric modes, with short circuits to ground, etc. Asymmetric modes caused by incomplete-phase commutations and wire breaks on the overhead line, as well as wire breaks with subsequent disconnection of power transformers that can affect the voltage level on the VT have been considered. The possibility of VT magnetizing with a prolonged voltage rise in symmetric modes, namely, the manifestation of the Ferranti effect with various loads at substations up to complete switching-off and power transformers switching off has been investigated. The analysis of the measuring voltage transformer operating conditions has been based on materials provided by the "Kolenergo" services.

  15. Development of internal manifold heat exchanger (IMHEX reg-sign) molten carbonate fuel cell stacks

    International Nuclear Information System (INIS)

    Marianowski, L.G.; Ong, E.T.; Petri, R.J.; Remick, R.J.

    1991-01-01

    The Institute of Gas Technology (IGT) has been in the forefront of molten carbonate fuel cell (MCFC) development for over 25 years. Numerous cell designs have been tested and extensive tests have been performed on a variety of gas manifolding alternatives for cells and stacks. Based upon the results of these performance tests, IGT's development efforts started focusing on an internal gas manifolding concept. This work, initiated in 1988, is known today as the IMHEX reg-sign concept. MCP has developed a comprehensive commercialization program loading to the sale of commercial units in 1996. MCP's role is in the manufacture of stack components, stack assembly, MCFC subsystem testing, and the design, marketing and construction of MCFC power plants. Numerous subscale (1 ft 2 ) stacks have been operated containing between 3 and 70 cells. These tests verified and demonstrated the viability of internal manifolding from technical (no carbonate pumping), engineering (relaxed part dimensional tolerance requirements), and operational (good gas sealing) aspects. Simplified fabrication, ease of assembly, the elimination of external manifolds and all associated clamping requirements has significantly lowered anticipated stack costs. Ongoing 1 ft 2 stack testing is generating performance and endurance characteristics as a function of system specified operating conditions. Commercial-sized, full-area stacks (10 ft 2 ) are in the process of being assembled and will be tested in November. This paper will review the recent developments the MCFC scale-up and manufacture work of MCP, and the research and development efforts of IGT which support those efforts. 17 figs

  16. Learning OpenStack networking (Neutron)

    CERN Document Server

    Denton, James

    2014-01-01

    If you are an OpenStack-based cloud operator with experience in OpenStack Compute and nova-network but are new to Neutron networking, then this book is for you. Some networking experience is recommended, and a physical network infrastructure is required to provide connectivity to instances and other network resources configured in the book.

  17. 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. © The Author(s) 2015.

  18. Operational limits and conditions and operating procedures for nuclear power plants. Safety guide

    International Nuclear Information System (INIS)

    2000-01-01

    This Safety Guide was prepared as part of the Agency's programme for establishing safety standards relating to nuclear power plants. The present Safety Guide supersedes the IAEA Safety Guide on Operational Limits and Conditions for Nuclear Power Plants which was issued in 1979 as Safety Series No. 50-SG-O3. For a nuclear power plant to be operated in a safe manner, the provisions made in the final design and subsequent modifications shall be reflected in limitations on plant operating parameters and in the requirements on plant equipment and personnel. Under the responsibility of the operating organization, these shall be developed during the design safety evaluation as a set of operational limits and conditions (OLCs). A major contribution to compliance with the OLCs is made by the development and utilization of operating procedures (OPs) that are consistent with and fully implement the OLCs. The requirements for the OLCs and OPs are established in Section 5 of the IAEA Safety Requirements publication Safety of Nuclear Power Plants: Operation, which this Safety Guide supplements. The purpose of this Safety Guide is to provide guidance on the development, content and implementation of OLCs and OPs. The Safety Guide is directed at both regulators and owners/operators. This Safety Guide covers the concept of OLCs, their content as applicable to land based stationary power plants with thermal neutron reactors, and the responsibilities of the operating organization regarding their establishment, modification, compliance and documentation. The OPs to support the implementation of the OLCs and to ensure their observance are also within the scope of this Safety Guide. The particular aspects of the procedures for maintenance, surveillance, in-service inspection and other safety related activities in connection with the safe operation of nuclear power plants are outside the scope of this Safety Guide but can be found in other IAEA Safety Guides. Section 2 indicates the

  19. Operational limits and conditions and operating procedures for nuclear power plants. Safety guide

    International Nuclear Information System (INIS)

    2005-01-01

    This Safety Guide was prepared as part of the Agency's programme for establishing safety standards relating to nuclear power plants. The present Safety Guide supersedes the IAEA Safety Guide on Operational Limits and Conditions for Nuclear Power Plants which was issued in 1979 as Safety Series No. 50-SG-O3. For a nuclear power plant to be operated in a safe manner, the provisions made in the final design and subsequent modifications shall be reflected in limitations on plant operating parameters and in the requirements on plant equipment and personnel. Under the responsibility of the operating organization, these shall be developed during the design safety evaluation as a set of operational limits and conditions (OLCs). A major contribution to compliance with the OLCs is made by the development and utilization of operating procedures (OPs) that are consistent with and fully implement the OLCs. The requirements for the OLCs and OPs are established in Section 5 of the IAEA Safety Requirements publication Safety of Nuclear Power Plants: Operation, which this Safety Guide supplements. The purpose of this Safety Guide is to provide guidance on the development, content and implementation of OLCs and OPs. The Safety Guide is directed at both regulators and owners/operators. This Safety Guide covers the concept of OLCs, their content as applicable to land based stationary power plants with thermal neutron reactors, and the responsibilities of the operating organization regarding their establishment, modification, compliance and documentation. The OPs to support the implementation of the OLCs and to ensure their observance are also within the scope of this Safety Guide. The particular aspects of the procedures for maintenance, surveillance, in-service inspection and other safety related activities in connection with the safe operation of nuclear power plants are outside the scope of this Safety Guide but can be found in other IAEA Safety Guides. Section 2 indicates the

  20. 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...... provide a significant contribution towards obtaining such a general model. Therefore, the main aim of the paper is to highlight the essential characteristics of marine system dynamics so as to provide a background for practitioners who would attempt future application of system identification techniques...

  1. Vertex operators, virasoro conditions and string dynamics in curved space

    International Nuclear Information System (INIS)

    Wadia, S.R.

    1987-01-01

    String propagation in a background metric and dilation field are considered in the context of conformal invariant field theory. A perturbatively renormalized tachyon vertex in the presence of these background fields is presented. This generalises the Berezinsky-Kosterlitz-Thouless construction. The equations of motion for the background fields and the wave equation for the vertex function emerge upon imposing the Virasoro gauge conditions on the vertex operator. This is equivalent to calculating the equation of motion Qvertical barpsi> = 0 in the BRST approach

  2. Operation of static series compensator under distorted utility conditions

    DEFF Research Database (Denmark)

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

    2005-01-01

    -average filter to detect the fundamental component of the measured voltages and currents (needed to control the SSC) while using a double vector control algorithm to improve the transient performance of the SSC. This is made in order to accurately control the fundamental voltage component at the load terminals...... 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...

  3. The one-sided Ap conditions and local maximal operator

    Czech Academy of Sciences Publication Activity Database

    Bernardis, A.L.; Gogatishvili, Amiran; Martin-Reyes, F. J.; Ortega Salvador, P.; Pick, L.

    2012-01-01

    Roč. 55, č. 1 (2012), s. 79-104 ISSN 0013-0915 R&D Projects: GA ČR GA201/08/0383; GA ČR GA201/05/2033 Institutional research plan: CEZ:AV0Z10190503 Keywords : one-sided Ap conditions * one-sided local maximal operator * quasi- Banach function spaces * variable-exponent Lebesgue spaces Subject RIV: BA - General Mathematics Impact factor: 0.561, year: 2012 http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8477114&fulltextType=RA&fileId=S0013091510000635

  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. The one-sided Ap conditions and local maximal operator

    Czech Academy of Sciences Publication Activity Database

    Bernardis, A.L.; Gogatishvili, Amiran; Martin-Reyes, F. J.; Ortega Salvador, P.; Pick, L.

    Roč. 55, č. 1 ( 2012 ), s. 79-104 ISSN 0013-0915 R&D Projects: GA ČR GA201/08/0383; GA ČR GA201/05/2033 Institutional research plan: CEZ:AV0Z10190503 Keywords : one-sided Ap conditions * one-sided local maximal operator * quasi-Banach function spaces * variable-exponent Lebesgue spaces Subject RIV: BA - General Mathematics Impact factor: 0.561, year: 2012 http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8477114&fulltextType=RA&fileId=S0013091510000635

  6. 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...

  7. Gender classification from video under challenging operating conditions

    Science.gov (United States)

    Mendoza-Schrock, Olga; Dong, Guozhu

    2014-06-01

    The literature is abundant with papers on gender classification research. However the majority of such research is based on the assumption that there is enough resolution so that the subject's face can be resolved. Hence the majority of the research is actually in the face recognition and facial feature area. A gap exists for gender classification under challenging operating conditions—different seasonal conditions, different clothing, etc.—and when the subject's face cannot be resolved due to lack of resolution. The Seasonal Weather and Gender (SWAG) Database is a novel database that contains subjects walking through a scene under operating conditions that span a calendar year. This paper exploits a subset of that database—the SWAG One dataset—using data mining techniques, traditional classifiers (ex. Naïve Bayes, Support Vector Machine, etc.) and traditional (canny edge detection, etc.) and non-traditional (height/width ratios, etc.) feature extractors to achieve high correct gender classification rates (greater than 85%). Another novelty includes exploiting frame differentials.

  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. 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)

  10. CORROSION OF COPPER PIPES JOINTS IN SIMULATED OPERATING CONDITIONS

    Directory of Open Access Journals (Sweden)

    Alexander Dodek

    2012-02-01

    Full Text Available Joining of copper pipes used for liquid media transport are made as demountable and fixation joints. This work deals with corrosion behavior of the joints made by soft soldering, hard soldering and fitting. Corrosion properties of the joints were studied after 11 month exposition in conditions simulated the operating environment. The experiment was made in the 3% NaCl solution, at temperature 20° C for 16 hours and at 80° C for 8 hours per day, the solution was flowing 8 hours by the average rate 0,27 m.s-1. Evaluation of the joints corrosion attacks was made visually, by light and electron microscopy with chemical analyses of corrosion products.

  11. CORROSION OF COPPER PIPES JOINTS IN SIMULATED OPERATING CONDITIONS

    Directory of Open Access Journals (Sweden)

    Alexander Dodek

    2011-10-01

    Full Text Available Joining of copper pipes used for liquid media transport are made as demountable and fixation joints. This work deals with corrosion behavior of the joints made by soft soldering, hard soldering and fitting. Corrosion properties of the joints were studied after 11 month exposition in conditions simulated the operating environment. The experiment was made in the 3% NaCl solution, at temperature 20° C for 16 hours and at 80° C for 8 hours per day, the solution was flowing 8 hours by the average rate 0,27 m.s-1. Evaluation of the joints corrosion attacks was made visually, by light and electron microscopy with chemical analyses of corrosion products.

  12. Identifying a "default" visual search mode with operant conditioning.

    Science.gov (United States)

    Kawahara, Jun-ichiro

    2010-09-01

    The presence of a singleton in a task-irrelevant domain can impair visual search. This impairment, known as the attentional capture depends on the set of participants. When narrowly searching for a specific feature (the feature search mode), only matching stimuli capture attention. When searching broadly (the singleton detection mode), any oddball captures attention. The present study examined which strategy represents the "default" mode using an operant conditioning approach in which participants were trained, in the absence of explicit instructions, to search for a target in an ambiguous context in which one of two modes was available. The results revealed that participants behaviorally adopted the singleton detection as the default mode but reported using the feature search mode. Conscious strategies did not eliminate capture. These results challenge the view that a conscious set always modulates capture, suggesting that the visual system tends to rely on stimulus salience to deploy attention.

  13. Accelerated testing of solid oxide fuel cell stacks for micro combined heat and power application

    DEFF Research Database (Denmark)

    Hagen, Anke; Høgh, Jens Valdemar Thorvald; Barfod, Rasmus

    2015-01-01

    of degradation, the profiles are executed faster than required for real applications. Operation with fast load cycling, both using hydrogen and methane/steam as fuels, does not accelerate degradation compared to constant operation, which demonstrates the maturity of SoA stacks and enables transferring knowledge...... from testing at constant conditions to dynamic operation. 7.5 times more cycles than required for 80,000 h lifetime as micro CHP are achieved on one-cell-stack level. The results also suggest that degradation mechanisms that proceed on a longer time-scale, such as creep, might have a more dominating...

  14. 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.

  15. Basic design parameters for the new PRR-1 stack

    International Nuclear Information System (INIS)

    Leopando, L.S.

    1994-01-01

    This report presents the results of work done to establish the basic design parameters of the new stack of the Philippine Research Reactor-1 (PRR-1). The work was undertaken to assure that the radioactive air emissions of the PRR-1, under both accident and normal operating conditions, will comply with modern safety practices. The work was done during June and July 1994. (author). 6 refs., 13 figs., 13 tabs

  16. Open stack thermal battery tests

    Energy Technology Data Exchange (ETDEWEB)

    Long, Kevin N. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Roberts, Christine C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Grillet, Anne M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Headley, Alexander J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Fenton, Kyle [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wong, Dennis [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ingersoll, David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-04-17

    We present selected results from a series of Open Stack thermal battery tests performed in FY14 and FY15 and discuss our findings. These tests were meant to provide validation data for the comprehensive thermal battery simulation tools currently under development in Sierra/Aria under known conditions compared with as-manufactured batteries. We are able to satisfy this original objective in the present study for some test conditions. Measurements from each test include: nominal stack pressure (axial stress) vs. time in the cold state and during battery ignition, battery voltage vs. time against a prescribed current draw with periodic pulses, and images transverse to the battery axis from which cell displacements are computed. Six battery configurations were evaluated: 3, 5, and 10 cell stacks sandwiched between 4 layers of the materials used for axial thermal insulation, either Fiberfrax Board or MinK. In addition to the results from 3, 5, and 10 cell stacks with either in-line Fiberfrax Board or MinK insulation, a series of cell-free “control” tests were performed that show the inherent settling and stress relaxation based on the interaction between the insulation and heat pellets alone.

  17. Deploying OpenStack

    CERN Document Server

    Pepple, Ken

    2011-01-01

    OpenStack was created with the audacious goal of being the ubiquitous software choice for building public and private cloud infrastructures. In just over a year, it's become the most talked-about project in open source. This concise book introduces OpenStack's general design and primary software components in detail, and shows you how to start using it to build cloud infrastructures. If you're a developer, technologist, or system administrator familiar with cloud offerings such as Rackspace Cloud or Amazon Web Services, Deploying OpenStack shows you how to obtain and deploy OpenStack softwar

  18. CRADA final report: Technical assessment of roll-to-roll operation of lamination process, thermal treatment, and alternative carbon fiber precursors for low-cost, high-efficiency manufacturing of flow battery stacks and other energy devices

    Energy Technology Data Exchange (ETDEWEB)

    Daniel, Claus [ORNL; Madden, Thomas [Lockheed Martin Corporation; Wood III, David L [ORNL; Muth, Thomas R [ORNL; Warrington, Curtis [Lockheed Martin Corporation; Ozcan, Soydan [ORNL; Manson, Hunter [Oak Ridge National Laboratory (ORNL); Tekinalp, Halil L [ORNL; Smith, Mark A [ORNL; Lu, Yuan [ORNL; Loretz, Jeremy [Oak Ridge National Laboratory (ORNL)

    2015-09-23

    Among the various stationary-storage technologies under development, redox flow batteries (RFBs) offer the greatest potential to deliver inexpensive, scalable, and efficient grid-scale electrical-energy storage. Unlike traditional sealed batteries, in a flow battery power and energy are decoupled. Cell area and cell count in the stack determine the device power, and the chemical storage volume determines the total energy. Grid-scale energy-storage applications require megawatt-scale devices, which require the assembly of hundreds of large-area, bipolar cells per power plant. The cell-stack is the single system component with the largest impact on capital cost (due to the large number of highly engineered components) and operating costs (determined by overall round-trip efficiency).

  19. 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.

  20. Conditional Reducibility of Certain Unbounded Nonnegative Hamiltonian Operator Functions

    NARCIS (Netherlands)

    Azizov, T.Ya.; Dijksma, A.; Gridneva, I.V.

    Let and be operators on a Hilbert space which are both self-adjoint and unitary and satisfy . We consider an operator function on [0, 1] of the form , , where is a closed densely defined Hamiltonian ( -skew-self-adjoint) operator on with and is a function on [0, 1] whose values are bounded operators

  1. A sensor-less methanol concentration control system based on feedback from the stack temperature

    International Nuclear Information System (INIS)

    An, Myung-Gi; Mehmood, Asad; Ha, Heung Yong

    2014-01-01

    Highlights: • A new sensor-less methanol control algorithm based on feedback from the stack temperature is developed. • Feasibility of the algorithm is tested using a DMFC system with a recirculating fuel loop. • The algorithm precisely controls the methanol concentration without the use of methanol sensors. • The sensor-less controller shortens the time that the DMFC system requires to go from start-up to steady-state. • This controller is effective in handling unexpected changes in the methanol concentration and stack temperature. - Abstract: A sensor-less methanol concentration control system based on feedback from the stack temperature (SLCCF) has been developed. The SLCCF algorithm is embedded into an in-house LabVIEW program that has been developed to control the methanol concentration in the feed of direct methanol fuel cells (DMFCs). This control method utilizes the close correlation between the stack temperature and the methanol concentration in the feed. Basically, the amounts of methanol to be supplied to the re-circulating feed stream are determined by estimating the methanol consumption rates under given operating conditions, which are then adjusted by a proportional–integral controller and supplied into the feed stream to maintain the stack temperature at a set value. The algorithm is designed to control the methanol concentration and the stack temperature for both start-up and normal operation processes. Feasibility tests with a 200 W-class DMFC system under various operating conditions confirm that the algorithm successfully maintains the methanol concentration in the feed as well as the stack temperature at set values, and the start-up time required for the DMFC system to reach steady-state operating conditions is reduced significantly compared with conventional sensor-less methods

  2. Proposal of stack Effect technology for predicted future years

    Science.gov (United States)

    Teddy Badai Samodra, FX; Adi Indrawan, Iwan

    2017-12-01

    Recently, stack effect is a general problem solver in providing vertical ventilation for urban environmental issues. However, study on resilient technology of stack effect for future years as predicted by climate trend should be conducted. Therefore, this research proposes a design of new technology on operable and adaptable vertical ventilation to the environmental change. The research method is conducted by comprehensive simulation of Ecotect Analysis, ANSYS Fluent and Matlab. Urban environment of Surabaya, as the research location, is the representative of tropical region. The results showed that the stack effect height and area could be modified instantly adjusting the environmental condition time by time in the future years. With 1.8 m of stack width, the proposed technology could capture 40 m3 of vertical air flow which is useful for physiological cooling and its dimension could be modified depending on the environmental condition. By providing resilient technology, predictable and sustainable ventilation method is offered to anticipate an unpredicted global warming and environmental change.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-11-15

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

  4. Silicon nanotube field effect transistor with core-shell gate stacks for enhanced high-performance operation and area scaling benefits

    KAUST Repository

    Fahad, Hossain M.

    2011-10-12

    We introduce the concept of a silicon nanotube field effect transistor whose unique core-shell gate stacks help achieve full volume inversion by giving a surge in minority carrier concentration in the near vicinity of the ultrathin channel and at the same time rapid roll-off at the source and drain junctions constituting velocity saturation-induced higher drive current-enhanced high performance per device with efficient real estate consumption. The core-shell gate stacks also provide superior short channel effects control than classical planar metal oxide semiconductor field effect transistor (MOSFET) and gate-all-around nanowire FET. The proposed device offers the true potential to be an ideal blend for quantum ballistic transport study of device property control by bottom-up approach and high-density integration compatibility using top-down state-of-the-art complementary metal oxide semiconductor flow. © 2011 American Chemical Society.

  5. 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...... of diagnosis for use in discussions of (a) the studies which are necessary in order to formulate the operator's diagnostic procedures and (b) the possibilities which exists for supporting these procedures through appropriate data processing and display in the control system. At the same time, attempts are made...... to connect ideas for display which currently are under consideration in the department to various phases of the diagnostic task which itself is postulated as being divided up into a sequence of subtasks each with its own typical features....

  6. Evaluation of corrosion inhibitor simulating conditions of operation

    Science.gov (United States)

    Gómez, O.; Aponte, H.; Vera, E.; Pineda, Y.

    2017-12-01

    Operating conditions at the head of oil wells are critical, in addition to injecting water to increase the pressure while maintaining production cause deterioration in the metallic structures that transport fluids. One way to maintain integrity is the injection of inhibitors which plays an important role in protecting the pipes. In this study a molecule N-PHENYL NITRONE was obtained, which was evaluated by electrochemical tests (LPR) and Tafel Polarization Curves in a reactor controlling environments containing different dosages, pressure values, temperatures and flow velocity using working electrodes tubing API N 80, the reactor was connected to a potentiostat to determine corrosion rates, allowing the analysis of the influence of each variable on the protective behaviour of the inhibitor, and its efficiency against the decrease of the deterioration of the pipes. Corrosion products are analysed by X-Ray Diffraction (XRD). Photographic records of the surface verify the formation of iron carbonate (FeCO3). In addition, a mathematical analysis of the independent variables is performed to evaluate the effect that it has on the efficiency of corrosion inhibition.

  7. Summarizing metocean operating conditions as a climatology of marine hazards

    Science.gov (United States)

    Reid, Heather; Finnis, Joel

    2018-03-01

    Marine occupations are plagued by some of the highest accident and mortality rates of any occupation, due in part to the variety and severity of environmental hazards presented by the ocean environment. In order to better study and communicate the potential impacts of these hazards on occupational health and safety, a semi-objective, hazard-focused climatology of a particularly dangerous marine environment (Northwestern Atlantic) has been developed. Specifically, climate has been summarized as the frequency with which responsible government agencies are expected to issue relevant warnings or watches, couching results in language relevant to marine stakeholders. Applying cluster analysis to warning/watch frequencies identified seven distinct `hazard climatologies', ranging from near-Arctic conditions to areas dominated by calm seas and warm waters. Spatial and temporal variability in these clusters reflects relevant annual cycles, such as the advance/retreat of sea ice and shifts in the Atlantic storm track; the clusters also highlight regions and seasons with comparable operational risks. Our approach is proposed as an effective means to summarize and communicate marine risk with stakeholders, and a potential framework for describing climate change impacts.

  8. OpenStack essentials

    CERN Document Server

    Radez, Dan

    2015-01-01

    If you need to get started with OpenStack or want to learn more, then this book is your perfect companion. If you're comfortable with the Linux command line, you'll gain confidence in using OpenStack.

  9. Mastering OpenStack

    CERN Document Server

    Khedher, Omar

    2015-01-01

    This book is intended for system administrators, cloud engineers, and system architects who want to deploy a cloud based on OpenStack in a mid- to large-sized IT infrastructure. If you have a fundamental understanding of cloud computing and OpenStack and want to expand your knowledge, then this book is an excellent checkpoint to move forward.

  10. 19 CFR 113.73 - Foreign trade zone operator bond conditions.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Foreign trade zone operator bond conditions. 113...; DEPARTMENT OF THE TREASURY CUSTOMS BONDS Customs Bond Conditions § 113.73 Foreign trade zone operator bond conditions. A bond of a foreign trade zone operator shall contain the conditions listed in this section and...

  11. Multilayer Piezoelectric Stack Actuator Characterization

    Science.gov (United States)

    Sherrit, Stewart; Jones, Christopher M.; Aldrich, Jack B.; Blodget, Chad; Bao, Xioaqi; Badescu, Mircea; Bar-Cohen, Yoseph

    2008-01-01

    Future NASA missions are increasingly seeking to use actuators for precision positioning to accuracies of the order of fractions of a nanometer. For this purpose, multilayer piezoelectric stacks are being considered as actuators for driving these precision mechanisms. In this study, sets of commercial PZT stacks were tested in various AC and DC conditions at both nominal and extreme temperatures and voltages. AC signal testing included impedance, capacitance and dielectric loss factor of each actuator as a function of the small-signal driving sinusoidal frequency, and the ambient temperature. DC signal testing includes leakage current and displacement as a function of the applied DC voltage. The applied DC voltage was increased to over eight times the manufacturers' specifications to investigate the correlation between leakage current and breakdown voltage. Resonance characterization as a function of temperature was done over a temperature range of -180C to +200C which generally exceeded the manufacturers' specifications. In order to study the lifetime performance of these stacks, five actuators from one manufacturer were driven by a 60volt, 2 kHz sine-wave for ten billion cycles. The tests were performed using a Lab-View controlled automated data acquisition system that monitored the waveform of the stack electrical current and voltage. The measurements included the displacement, impedance, capacitance and leakage current and the analysis of the experimental results will be presented.

  12. The effects of operator position, pallet orientation, and palletizing condition on low back loads in manual bag palletizing operations.

    Science.gov (United States)

    Gallagher, Sean; Heberger, John R

    2015-05-01

    Many mining commodities are packaged and shipped using bags. Small bags are typically loaded onto pallets for transport and require a significant amount of manual handling by workers. This specific task of manual bag handling has been associated with the development of musculoskeletal disorders (MSDs), especially low back disorders. This study evaluates the biomechanical demands of different work layouts when performing manual palletizing of small bags, and evaluates the biomechanical stresses associated with different stacking techniques. Results indicate that peak forward bending moments as well as spinal compression and shear forces are higher when the pallet is situated at the side of the conveyor as opposed to the end of the conveyor. At low levels of the pallet, controlled bag placement results in higher peak forward bending moments than stacking at higher levels and when dropping the bag to lower levels. The results of this study will be used to inform the development of an audit tool for bagging operations in the mining industry. In many cases for workers loading small bags, compression forces exceed the NIOSH criterion of 3400 N. Orientation of the pallet has a significant impact on spinal compression, and positioning the pallet at the end of the conveyor reduces the estimated compressive loading on the lumbar spine by approximately 800 N.

  13. Optimal operating conditions for maximum biogas production in anaerobic bioreactors

    International Nuclear Information System (INIS)

    Balmant, W.; Oliveira, B.H.; Mitchell, D.A.; Vargas, J.V.C.; Ordonez, J.C.

    2014-01-01

    The objective of this paper is to demonstrate the existence of optimal residence time and substrate inlet mass flow rate for maximum methane production through numerical simulations performed with a general transient mathematical model of an anaerobic biodigester introduced in this study. It is herein suggested a simplified model with only the most important reaction steps which are carried out by a single type of microorganisms following Monod kinetics. The mathematical model was developed for a well mixed reactor (CSTR – Continuous Stirred-Tank Reactor), considering three main reaction steps: acidogenesis, with a μ max of 8.64 day −1 and a K S of 250 mg/L, acetogenesis, with a μ max of 2.64 day −1 and a K S of 32 mg/L, and methanogenesis, with a μ max of 1.392 day −1 and a K S of 100 mg/L. The yield coefficients were 0.1-g-dry-cells/g-pollymeric compound for acidogenesis, 0.1-g-dry-cells/g-propionic acid and 0.1-g-dry-cells/g-butyric acid for acetogenesis and 0.1 g-dry-cells/g-acetic acid for methanogenesis. The model describes both the transient and the steady-state regime for several different biodigester design and operating conditions. After model experimental validation, a parametric analysis was performed. It was found that biogas production is strongly dependent on the input polymeric substrate and fermentable monomer concentrations, but fairly independent of the input propionic, acetic and butyric acid concentrations. An optimisation study was then conducted and optimal residence time and substrate inlet mass flow rate were found for maximum methane production. The optima found were very sharp, showing a sudden drop of methane mass flow rate variation from the observed maximum to zero, within a 20% range around the optimal operating parameters, which stresses the importance of their identification, no matter how complex the actual bioreactor design may be. The model is therefore expected to be a useful tool for simulation, design, control and

  14. Detailed Electrochemical Characterisation of Large SOFC Stacks

    DEFF Research Database (Denmark)

    Mosbæk, Rasmus Rode; Hjelm, Johan; Barfod, R.

    2012-01-01

    As solid oxide fuel cell (SOFC) technology is moving closer to a commercial break through, lifetime limiting factors, determination of the limits of safe operation and methods to measure the “state-of-health” of operating cells and stacks are becoming of increasing interest. This requires applica...... out at a range of ac perturbation amplitudes in order to investigate linearity of the response and the signal-to-noise ratio. Separation of the measured impedance into series and polarisation resistances was possible....... to analyse in detail. Today one is forced to use mathematical modelling to extract information about existing gradients and cell resistances in operating stacks, as mature techniques for local probing are not available. This type of spatially resolved information is essential for model refinement...... and validation, and helps to further the technological stack development. Further, more detailed information obtained from operating stacks is essential for developing appropriate process monitoring and control protocols for stack and system developers. An experimental stack with low ohmic resistance from Topsoe...

  15. The new operating conditions of French nuclear power plants

    International Nuclear Information System (INIS)

    Leclercq, J.

    1986-01-01

    Six themes are examined: France's unique position in view of the size of its nuclear operating plant, the role of nuclear power in matching electricity supply to demand, the excellent flexibility provided by PWR facilities in operation, the approaches used in the field of automatic operational control systems, the systematic use of data processing for maintenance and generation and the gains in productivity that can be gained as a result of improving fuel use [fr

  16. Operant Conditioning: A Tool for Special Physical Educators in the 1980s.

    Science.gov (United States)

    Dunn, John M.; French, Ron

    1982-01-01

    The usefulness of operant conditioning for the special physical educator in managing behavior problems is pointed out, and steps to follow in applying operant conditioning techniques are outlined. (SB)

  17. Analyses of Large Coal-Based SOFCs for High Power Stack Block Development

    Energy Technology Data Exchange (ETDEWEB)

    Recknagle, Kurtis P; Koeppel, Brian J

    2010-10-01

    This report summarizes the numerical modeling and analytical efforts for SOFC stack development performed for the coal-based SOFC program. The stack modeling activities began in 2004, but this report focuses on the most relevant results obtained since August 2008. This includes the latter half of Phase-I and all of Phase-II activities under technical guidance of VPS and FCE. The models developed to predict the thermal-flow-electrochemical behaviors and thermal-mechanical responses of generic planar stacks and towers are described. The effects of cell geometry, fuel gas composition, on-cell reforming, operating conditions, cell performance, seal leak, voltage degradation, boundary conditions, and stack height are studied. The modeling activities to evaluate and achieve technical targets for large stack blocks are described, and results from the latest thermal-fluid-electrochemical and structural models are summarized. Modeling results for stack modifications such as scale-up and component thickness reduction to realize cost reduction are presented. Supporting modeling activities in the areas of cell fabrication and loss of contact are also described.

  18. 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.

  19. 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

    -ternary catalyst materials for higher performance, documents enhanced durability under multiple types of accelerated tests by factors of 10x to 50x over conventional catalysts, & demonstrates their performance & durability in large area MEA FC stack tests. The PEMFC ion exchange membrane is the other key functioning FC component on which work was completed. While improvements have been made to standard PFSA type membranes, they still require humidification to achieve adequate proton conductivity & so their use at elevated temperatures & drier operating conditions is limited. Membranes with increased durability & conductivity under hotter, drier conditions allow the use of FC's in many applications, particularly automotive. Towards this goal, 2 approaches were pursued in the work reported here. The first part was designed for immediate application at drier conditions & operating temperatures between 85C and 120C, focused on the development of a membrane based on a low equivalent weight (EW), perfluorinated sulfonic acid (PFSA) ionomer for good ionic conductivity at low humidification, & the use of stabilizing additives for improved oxidative stability. The ionomer used was developed at 3M & has a shorter acid containing side-chain than the Nafion™ ionomer. This ionomer also has a higher Tα & higher modulus than that of a Nafion™ membrane of the same EW, allowing lower EW ionomers to be prepared with very good mechanical properties. In addition, more than 50 stabilizing additives were evaluated in ex-situ, Fenton’s tests & more than 10 of these were incorporated into membranes & evaluated in accelerated FC tests. This work led to thin (25-30 micron) cast membranes with substantially improved conductivity & durability under simulated automotive conditions, compared to membranes currently available. The 2nd body of membrane work was focused on developing & characterizing 3 approaches for making new PEM's for operation under hot (>120C) & dry (dew point <80C) FC

  20. Study of safety relief valve operation under ATWS conditions

    International Nuclear Information System (INIS)

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

    1979-01-01

    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

  1. Titanium-tungsten nanocrystals embedded in a SiO2/Al2O3 gate dielectric stack for low-voltage operation in non-volatile memory

    International Nuclear Information System (INIS)

    Yang Shiqian; Wang Qin; Zhang Manhong; Long Shibing; Liu Jing; Liu Ming

    2010-01-01

    Titanium-tungsten nanocrystals (NCs) were fabricated by a self-assembly rapid thermal annealing (RTA) process. Well isolated Ti 0.46 W 0.54 NCs were embedded in the gate dielectric stack of SiO 2 /Al 2 O 3 . A metal-oxide-semiconductor (MOS) capacitor was fabricated to investigate its application in a non-volatile memory (NVM) device. It demonstrated a large memory window of 6.2 V in terms of flat-band voltage (V FB ) shift under a dual-directional sweeping gate voltage of - 10 to 10 V. A 1.1 V V FB shift under a low dual-directional sweeping gate voltage of - 4 to 4 V was also observed. The retention characteristic of this MOS capacitor was demonstrated by a 0.5 V memory window after 10 4 s of elapsed time at room temperature. The endurance characteristic was demonstrated by a program/erase cycling test.

  2. 14 CFR 91.527 - Operating in icing conditions.

    Science.gov (United States)

    2010-01-01

    ... Aviation Regulation No. 23, or those for transport category airplane type certification, no pilot may fly... for transport category airplane type certification, no pilot may fly an airplane into known or...-Powered Multiengine Airplanes and Fractional Ownership Program Aircraft § 91.527 Operating in icing...

  3. Transient pressure measurements at part load operating condition of ...

    Indian Academy of Sciences (India)

    Rahul Goyal

    2 Water Power Laboratory, Department of Energy and Process Engineering, Norwegian University of Science and Technology .... speed = 0.27) is in operation at the Tokke power plant,. Norway. A schematic of the test rig is presented in figure 1. Water from the basement was pumped to the overhead tank which flowed ...

  4. 14 CFR 121.629 - Operation in icing conditions.

    Science.gov (United States)

    2010-01-01

    ... specific duties and responsibilities of each operational position or group responsible for getting the... and annual recurrent ground training and testing for flight crewmembers and qualification for all... inspection procedures; (vii) Techniques for recognizing contamination on the aircraft. (3) The certificate...

  5. 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.)

  6. 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...

  7. Analysis of Actual Operating Conditions of an Off-grid Solid Oxide Fuel Cell

    Energy Technology Data Exchange (ETDEWEB)

    Dennis Witmer; Thomas Johnson; Jack Schmid

    2008-12-31

    Fuel cells have been proposed as ideal replacements for other technologies in remote locations such as Rural Alaska. A number of suppliers have developed systems that might be applicable in these locations, but there are several requirements that must be met before they can be deployed: they must be able to operate on portable fuels, and be able to operate with little operator assistance for long periods of time. This project was intended to demonstrate the operation of a 5 kW fuel cell on propane at a remote site (defined as one without access to grid power, internet, or cell phone, but on the road system). A fuel cell was purchased by the National Park Service for installation in their newly constructed visitor center at Exit Glacier in the Kenai Fjords National Park. The DOE participation in this project as initially scoped was for independent verification of the operation of this demonstration. This project met with mixed success. The fuel cell has operated over 6 seasons at the facility with varying degrees of success, with one very good run of about 1049 hours late in the summer of 2006, but in general the operation has been below expectations. There have been numerous stack failures, the efficiency of electrical generation has been lower than expected, and the field support effort required has been far higher than expected. Based on the results to date, it appears that this technology has not developed to the point where demonstrations in off road sites are justified.

  8. 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...

  9. Hydrodynamic Modelling and Experimental Analysis of FE-DMFC Stacks

    Science.gov (United States)

    Kablou, Yashar

    Direct methanol fuel cells (DMFCs) present some unique features such as having liquid fuel, quick refueling process, compact design and high energy density. These characteristics make them incredibly suitable as a promising power source for portable electronic applications, such as cell phones or laptop computers. Despite of these positive aspects, the commercial development of DMFCs has nevertheless been hindered by some important issues such as, carbon dioxide formation at the anode compartment and, methanol crossover through the membrane. Many researchers have tried to model the two-phase flow behavior inside the DMFC anode compartment using the "homogenous flow modelling" approach, which has proven to be inaccurate specially when dealing with DMFC stacks. On the other hand, several strategies to prevent methanol crossover have been suggested in the literature, including the use of a flowing electrolyte between the DMFC anode and cathode compartments. Preliminary tests on flowing electrolyte direct methanol fuel cells (FE-DMFCs) have shown promising results; however, further investigation should be carried out on the stack level. In the first part of this study, a quasi two-dimensional numerical model was developed, to predict the two-phase flow behavior within the DMFC anode compartment, both in single cell and stack levels. Various types of flow modelling approaches and void fraction correlations were utilized to estimate the pressure drop across the anode compartment. It was found that the "separated flow modelling" approach, as well as CISE correlation for void fraction (developed at the CISE labs in Milan), yield the best results. In the second part, a five-cell FE-DMFC stack unit with a parallel serpentine flow bed design and U-type manifold configuration, was developed and tested at various operating conditions. It was found that, the flowing electrolyte effectively reduced methanol crossover and, improved the stack performance.

  10. 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…

  11. 14 CFR 135.227 - Icing conditions: Operating limitations.

    Science.gov (United States)

    2010-01-01

    ... for transport category airplane type certification, no pilot may fly— (1) Under IFR into known or... authorized by the Administrator. (b) No certificate holder may authorize an airplane to take off and no pilot may take off an airplane any time conditions are such that frost, ice, or snow may reasonably be...

  12. Development of internal manifold heat exchanger (IMHEX reg sign ) molten carbonate fuel cell stacks

    Energy Technology Data Exchange (ETDEWEB)

    Marianowski, L.G.; Ong, E.T.; Petri, R.J.; Remick, R.J.

    1991-01-01

    The Institute of Gas Technology (IGT) has been in the forefront of molten carbonate fuel cell (MCFC) development for over 25 years. Numerous cell designs have been tested and extensive tests have been performed on a variety of gas manifolding alternatives for cells and stacks. Based upon the results of these performance tests, IGT's development efforts started focusing on an internal gas manifolding concept. This work, initiated in 1988, is known today as the IMHEX{reg sign} concept. MCP has developed a comprehensive commercialization program loading to the sale of commercial units in 1996. MCP's role is in the manufacture of stack components, stack assembly, MCFC subsystem testing, and the design, marketing and construction of MCFC power plants. Numerous subscale (1 ft{sup 2}) stacks have been operated containing between 3 and 70 cells. These tests verified and demonstrated the viability of internal manifolding from technical (no carbonate pumping), engineering (relaxed part dimensional tolerance requirements), and operational (good gas sealing) aspects. Simplified fabrication, ease of assembly, the elimination of external manifolds and all associated clamping requirements has significantly lowered anticipated stack costs. Ongoing 1 ft{sup 2} stack testing is generating performance and endurance characteristics as a function of system specified operating conditions. Commercial-sized, full-area stacks (10 ft{sup 2}) are in the process of being assembled and will be tested in November. This paper will review the recent developments the MCFC scale-up and manufacture work of MCP, and the research and development efforts of IGT which support those efforts. 17 figs.

  13. 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....

  14. Positivity for equations involving polyharmonic operators with Dirichlet boundary conditions

    NARCIS (Netherlands)

    Grunau, H.-Ch.; Sweers, G.

    1996-01-01

    Cranston, Fabes and Zhao ([26], [5]) established the uniform bound sup x; y 2 x 6= y R G1;n (x; z)G1;n (z; y) dz G1;n (x; y) M < 1; (1) where G1;n (x; y) is the Green function for the Laplacian - with Dirichlet boundary conditions on a Lipschitz domain - Rn with n 3 (see [27] for n = 2).

  15. Pellet reduction properties under different blast furnace operating conditions

    OpenAIRE

    Leimalm, Ulrika

    2006-01-01

    One of the aims of modern blast furnace (BF) ironmaking is to reduce coke consumption. One way is to increase the injection of reduction agents, such as pulverized coal. An increase in pulverized coal injection rate (PCR) will affect the blast furnace process and the conditions for iron oxide reduction. Changes in PCR influence the composition of the ascending gases and the in-furnace temperature isotherms. The performed tests involve full-scale, pilot and laboratory investigations. Raw mater...

  16. 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…

  17. Stack filter classifiers

    Energy Technology Data Exchange (ETDEWEB)

    Porter, Reid B [Los Alamos National Laboratory; Hush, Don [Los Alamos National Laboratory

    2009-01-01

    Just as linear models generalize the sample mean and weighted average, weighted order statistic models generalize the sample median and weighted median. This analogy can be continued informally to generalized additive modeels in the case of the mean, and Stack Filters in the case of the median. Both of these model classes have been extensively studied for signal and image processing but it is surprising to find that for pattern classification, their treatment has been significantly one sided. Generalized additive models are now a major tool in pattern classification and many different learning algorithms have been developed to fit model parameters to finite data. However Stack Filters remain largely confined to signal and image processing and learning algorithms for classification are yet to be seen. This paper is a step towards Stack Filter Classifiers and it shows that the approach is interesting from both a theoretical and a practical perspective.

  18. Titanium-tungsten nanocrystals embedded in a SiO(2)/Al(2)O(3) gate dielectric stack for low-voltage operation in non-volatile memory.

    Science.gov (United States)

    Yang, Shiqian; Wang, Qin; Zhang, Manhong; Long, Shibing; Liu, Jing; Liu, Ming

    2010-06-18

    Titanium-tungsten nanocrystals (NCs) were fabricated by a self-assembly rapid thermal annealing (RTA) process. Well isolated Ti(0.46)W(0.54) NCs were embedded in the gate dielectric stack of SiO(2)/Al(2)O(3). A metal-oxide-semiconductor (MOS) capacitor was fabricated to investigate its application in a non-volatile memory (NVM) device. It demonstrated a large memory window of 6.2 V in terms of flat-band voltage (V(FB)) shift under a dual-directional sweeping gate voltage of - 10 to 10 V. A 1.1 V V(FB) shift under a low dual-directional sweeping gate voltage of - 4 to 4 V was also observed. The retention characteristic of this MOS capacitor was demonstrated by a 0.5 V memory window after 10(4) s of elapsed time at room temperature. The endurance characteristic was demonstrated by a program/erase cycling test.

  19. 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.

  20. Verification of design rules for EUROFER under TBM operating conditions

    International Nuclear Information System (INIS)

    Sunyk, R.; Aktaa, J.

    2007-01-01

    The aim of the activity presented in this work is, firstly, an evaluation of existing design rules considered for austenitic steels exhibiting cycle-by-cycle hardening, in contrast to the reduced-activation ferritic-martensitic steels (RAFM), which soften under cyclic loading. Secondly, we are aimed in a definition of the range of operating temperatures and loads for the current design of the test blanket module (TBM). Results of cycling tests of the EUROFER 97 have been thereby used to adjust material parameters needed for an ABAQUS-own combined non-linear isotropic-kinematic hardening model. Furthermore, a visco-plastic material model considering material damage and implemented recently as an ABAQUS user material (UMAT) has been also applied for simulations. Some important design rules within the elastic route have been evaluated and their predictions have been compared to results of cyclic simulations using the advanced material models mentioned above

  1. On Stack Reconstruction Problem

    Directory of Open Access Journals (Sweden)

    V. D. Аkeliev

    2009-01-01

    Full Text Available The paper describes analytical investigations that study relation of fuel combustion regimes with concentration values of sulphur anhydride in flue gases and acid dew point. Coefficients of convective heat transfer at internal and external surfaces of stacks have been determined in the paper. The paper reveals the possibility to reconstruct stacks while using gas discharging channel made of composite material on the basis of glass-reinforced plastic which permits to reduce thermo-stressed actions on reinforced concrete and increase volume of released gases due to practically two-fold reduction of gas-dynamic pressure losses along the pipe length.

  2. Laser pulse stacking method

    Science.gov (United States)

    Moses, E.I.

    1992-12-01

    A laser pulse stacking method is disclosed. A problem with the prior art has been the generation of a series of laser beam pulses where the outer and inner regions of the beams are generated so as to form radially non-synchronous pulses. Such pulses thus have a non-uniform cross-sectional area with respect to the outer and inner edges of the pulses. The present invention provides a solution by combining the temporally non-uniform pulses in a stacking effect to thus provide a more uniform temporal synchronism over the beam diameter. 2 figs.

  3. Pressure sores: an operant conditioning approach to prevention.

    Science.gov (United States)

    Malament, I R; Dunn, M E; Davis, R

    1975-04-01

    A training system for the prevention of pressure sores has been designed to teach the paralytic person to relieve pressure intermittently from his ischium while sitting in a wheelchair. The system automates the training of wheelchair pushups, and conditions the person into exercising, based upon modified avoidance learning procedures. Results indicate that the paralytic person can be trained to pushup intermittently and efficiently using this system, thus reducing the incidence of pressure sore formation. Further long-term study is needed to assess the effectiveness of the training system as a preventative program for pressure sores.

  4. Sampled-time control of a microbial fuel cell stack

    Science.gov (United States)

    Boghani, Hitesh C.; Dinsdale, Richard M.; Guwy, Alan J.; Premier, Giuliano C.

    2017-07-01

    Research into microbial fuel cells (MFCs) has reached the point where cubic metre-scale systems and stacks are being built and tested. Apart from performance enhancement through catalysis, materials and design, an important research area for industrial applicability is stack control, which can enhance MFCs stack power output. An MFC stack is controlled using a sampled-time digital control strategy, which has the advantage of intermittent operation with consequent power saving, and when used in a hybrid series stack connectivity, can avoid voltage reversals. A MFC stack comprising four tubular MFCs was operated hydraulically in series. Each MFC was connected to an independent controller and the stack was connected electrically in series, creating a hybrid-series connectivity. The voltage of each MFC in the stack was controlled such that the overall series stack voltage generated was the algebraic sum (1.26 V) of the individual MFC voltages (0.32, 0.32, 0.32 and 0.3). The controllers were able to control the individual voltages to the point where 2.52 mA was drawn from the stack at a load of 499.9 Ω (delivering 3.18 mW). The controllers were able to reject the disturbances and perturbations caused by electrical loading, temperature and substrate concentration.

  5. 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

  6. 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...

  7. Application of current steps and design of experiments methodology to the detection of water management faults in a proton exchange membrane fuel cell stack

    Science.gov (United States)

    Moçotéguy, Philippe; Ludwig, Bastian; Yousfi Steiner, Nadia

    2016-01-01

    We apply a 25-1 fractional factorial Design of Experiments (DoE) test plan in order to discriminate the direct effects and interactions of five factors on the water management of a 500 We PEMFC stack. The stack is submitted to current steps between different operating levels and several responses are extracted for the DoE analysis. A strong ageing effect on stack and cell performances is observed. Therefore, in order to perform the DoE analysis, responses which values are too strongly affected by ageing are ;corrected; prior to the analysis. A ;virtual; stack, considered as ;healthy;, is also ;reconstructed; by ;putting in series; the cells exhibiting very low performance drop. The results show that stacks and cells' resistivities are mostly impacted by direct effects of both temperature and cathodic inlet relative humidity and by compensating interaction between temperature and anodic overstoichiometric ratio. It also appears that two responses are able to distinguish a ;healthy; stack from a degraded stack: heterogeneities in cell voltages and cell resistivities distributions. They are differently impacted by considered effects and interactions. Thus, a customised water management strategy could be developed, depending on the stack's state of health to maintain it in the best possible operating conditions.

  8. Development of the electric utility dispersed use PAFC stack

    Energy Technology Data Exchange (ETDEWEB)

    Horiuchi, Hiroshi; Kotani, Ikuo [Mitsubishi Electric Co., Kobe (Japan); Morotomi, Isamu [Kansai Electric Power Co., Hyogo (Japan)] [and others

    1996-12-31

    Kansai Electric Power Co. and Mitsubishi Electric Co. have been developing the electric utility dispersed use PAFC stack operated under the ambient pressure. The new cell design have been developed, so that the large scale cell (1 m{sup 2} size) was adopted for the stack. To confirm the performance and the stability of the 1 m{sup 2} scale cell design, the short stack study had been performed.

  9. Sleep supports inhibitory operant conditioning memory inAplysia.

    Science.gov (United States)

    Vorster, Albrecht P A; Born, Jan

    2017-06-01

    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 times, at Training, Retrieval 1, and Retrieval 2, with 17-h intervals between tests. Compared with Wake animals, remaining awake between Training and Retrieval 1, Sleep animals with undisturbed post-training sleep, performed significantly better at Retrieval 1 and 2. Control experiments testing retrieval only after ∼34 h, confirmed the consolidating effect of sleep occurring within 17 h after training. © 2017 Vorster and Born; Published by Cold Spring Harbor Laboratory Press.

  10. Astronomical and Meteorological Conditions of a Solar System Operation

    Science.gov (United States)

    Proszak-Miąsik, Danuta; Bukowska, Maria; Nowak, Krzysztof; Rabczak, Sławomir

    2017-10-01

    Acquisition and processing of as much solar energy for heating and electricity generation in Poland and in the world is a very important objective in the policy of alternative energy sources. The main problem with the reception of solar energy by solar collectors is vary energy supply at different times of day and year and low flux density of radiation. The term of solar radiation one mean transmission or emission of energy in the form of electromagnetic waves. The radiation emitted from the surface of the sun spreads out in all directions in space, reaches the Earth’s surface in only partly, especially the solar collectors. The most important parameters characterizing solar radiation are daily, monthly and annual sum of solar radiation. Its express the amount of solar energy which falls on a unit area at a given time. Number of hours of sunshine during the day are dependent on two key factors. The first one is the time from the sunrise to sunset, which strongly depends on the date and latitude. The second factor is the weather (clouds), influences solar radiation, radiation in touch with clouds is absorbed and dissipated. This publication shows the impact on the energy yield of the flat collector installation and astronomical conditions (angle of inclination and declination of solar), and climate. The calculations of determining the astronomical conditions of the place where the installation is located ware analyzed. The solar installation is located in Rzeszow (Poland) and the plate collector placed on the roof of building. Based on specific methodology for selected days the calculation of the elevation angle of the Sun, hourly angle, the sun azimuth and angle of incidence of the radiation on any plane were set. The results are shown in diagrams. The effect of cloud cover on the acquisition of solar energy by the collector is also shown.

  11. Thermal operations conditions in a national waste terminal storage facility

    International Nuclear Information System (INIS)

    1976-09-01

    Some of the major technical questions associated with the burial of radioactive high-level wastes in geologic formations are related to the thermal environments generated by the waste and the impact of this dissipated heat on the surrounding environment. The design of a high level waste storage facility must be such that the temperature variations that occur do not adversely affect operating personnel and equipment. The objective of this investigation was to assist OWI by determining the thermal environment that would be experienced by personnel and equipment in a waste storage facility in salt. Particular emphasis was placed on determining the maximum floor and air temperatures with and without ventilation in the first 30 years after waste emplacement. The assumed facility design differs somewhat from those previously analyzed and reported, but many of the previous parametric surveys are useful for comparison. In this investigation a number of 2-dimensional and 3-dimensional simulations of the heat flow in a repository have been performed on the HEATING5 and TRUMP heat transfer codes. The representative repository constructs used in the simulations are described, as well as the computational models and computer codes. Results of the simulations are presented and discussed. Comparisons are made between the recent results and those from previous analyses. Finally, a summary of study limitations, comparisons, and conclusions is given

  12. Determination of Pressure Fluctuations in Rotor Bundle of Centrifugal Compressor at Critical Conditions of Operation

    Science.gov (United States)

    Levashov, V. A.; Lyubchenko, K. Yu

    2017-08-01

    This article describes the physical processes that occur in the stage flow part of the compressor while it is operating and can create conditions for the occurrence of forced vibrations, which in turn can lead to the destruction of the impellers. Critical conditions of compressor operation are determined. To understand that critical condition of operation is cause of the destruction of the impellers, transient CFD analysis was carried for test stage of compressor. The obtained pressure fluctuation amplitudes allow to evaluate the critical conditions of compressor operation.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-08-15

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

  14. po_stack_movie

    DEFF Research Database (Denmark)

    2009-01-01

    po_stack® er et reolsystem, hvis enkle elementer giver stor flexibilitet, variation og skulpturel virkning. Elementerne stables og forskydes frit, så reolens rum kan vendes til begge sider, være åbne eller lukkede og farvekombineres ubegrænset. Reolen kan let ombygges, udvides eller opdeles, når ...

  15. Learning SaltStack

    CERN Document Server

    Myers, Colton

    2015-01-01

    If you are a system administrator who manages multiple servers, then you know how difficult it is to keep your infrastructure in line. If you've been searching for an easier way, this book is for you. No prior experience with SaltStack is required.

  16. Baroreflex unimpaired by operant avoidance or classical aversive conditioning in dogs.

    Science.gov (United States)

    Shammas, R A; Denison, A L; Pfennig, T W; Hemker, D P; Stephenson, R B

    1988-06-01

    Previous studies showed that baroreflex control of heart rate is impaired during operant shock avoidance conditioning and classical aversive conditioning. However, the effects of such "emotionally stressful" paradigms on the ability of the baroreflex to control arterial pressure have not been directly assessed. We prepared the carotid sinus regions of dogs for reversible isolation from the systemic circulation, and we derived complete stimulus-response relations for the effects of carotid sinus pressure on both heart rate and arterial pressure. For any given carotid sinus pressure, arterial pressure and heart rate were higher during operant shock-avoidance conditioning and during classical aversive conditioning than in a neutral environment, which indicates an upward resetting of the baroreflex. However, threshold and saturation carotid sinus pressures were unaffected by operant conditioning or classical conditioning, which indicates that the baroreceptors themselves were not reset. The ranges over which the carotid baroreflex could vary arterial pressure and heart rate were significantly increased during both operant conditioning and classical conditioning. Baroreflex gain was unchanged during operant conditioning and was significantly increased during classical conditioning. We conclude that the baroreflex is not impaired during operant shock-avoidance conditioning or classical aversive conditioning in dogs. However, the baroreflex is reset and regulates blood pressure at an elevated level.

  17. A conditioned reinforcer did not help to maintain an operant conditioning in the absence of a primary reinforcer in horses.

    Science.gov (United States)

    Lansade, Léa; Calandreau, Ludovic

    2018-01-01

    The use of conditioned reinforcers is increasingly promoted in animal training. Surprisingly, the efficiency of their use remains to be demonstrated in horses. This study aimed to determine whether an auditory signal which had previously been associated with a food reward 288 times could be used as a conditioned reinforcer to replace the primary reinforcer in an unrelated operant conditioning procedure. Fourteen horses were divided into two groups of 7: No Reinforcement (NR) and Conditioned Reinforcement (CR). All horses underwent nine sessions of Pavlovian conditioning during which the word "good" was associated with food (32 associations/session). The horses then followed five sessions of operant conditioning (30 trials/session) during which they had to touch a cone signaled by an experimenter to receive a food reward. The last day, horses underwent one test session of the operant response: no reward was given, but the word "good" was said each time a CR horse touched the cone. Nothing was said in the NR group. CR horses did not achieve more correct trials than NR horses during the test. These findings again show that the conditioned reinforcement was ineffective when used instead of the primary reinforcement to maintain conditioning. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Experiment and numerical simulation on the performance of a kw-scale molten carbonate fuel cell stack

    Directory of Open Access Journals (Sweden)

    L. J. Yu

    2007-12-01

    Full Text Available A high-temperature molten carbonate fuel cell stack was studied experimentally and computationally. Experimental data for fuel cell temperature was obtained when the stack was running under given operational conditions. A 3-D CFD numerical model was set up and used to simulate the central fuel cell in the stack. It includes the mass, momentum and energy conservation equations, the ideal gas law and an empirical equation for cell voltage. The model was used to simulate the transient behavior of the fuel cell under the same operational conditions as those of the experiment. Simulation results show that the transient temperature and current and power densities reach their maximal values at the channel outlet. A comparison of the modeling results and the experimental data shows the good agreement.

  19. 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....

  20. Operant Conditioning Concepts in Introductory Psychology Textbooks and Their Companion Web Sites

    Science.gov (United States)

    Sheldon, Jane P.

    2002-01-01

    Psychology instructors and textbook authors rate operant conditioning as one of the most essential concepts for students to learn, yet textbook writers, as well as students, can fall prey to misconceptions. This study is a content analysis of the presentation of operant conditioning in introductory psychology textbooks and their companion Web…

  1. The Establishment and Administration of Operant Conditioning Programs in a State Hospital for the Retarded.

    Science.gov (United States)

    Ball, Thomas S., Ed.

    Seven articles treat the establishment of operant conditioning programs for the mentally retarded at Pacific State Hospital in California. Emphasis is on the administrative rather than the demonstration of research aspects of operant conditioning programs. Following an introduction and overview, the medical director's point of view on operant…

  2. 40 CFR 61.33 - Stack sampling.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Stack sampling. 61.33 Section 61.33 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL... sampling. (a) Unless a waiver of emission testing is obtained under § 61.13, each owner or operator...

  3. 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.

  4. Self-injurious behavior in Rett syndrome: interactions between features of Rett syndrome and operant conditioning.

    Science.gov (United States)

    Oliver, C; Murphy, G; Crayton, L; Corbett, J

    1993-03-01

    Operant and biological theories of the cause of self-injurious behavior (SIB) in people with a mental handicap are often viewed as mutually exclusive. In this single case study, interactions between features of Rett syndrome and operant conditioning as determinants of SIB are examined. Functional analysis by analog methodology indicated different functions for two forms of SIB shown by the subject: automatic reinforcement by sensory stimulation and escape from social interactions. It is suggested that features of Rett syndrome established conditions under which operant conditioning of self-injurious responding was maximized. The implications of this interaction between features of syndromes and operant conditioning for the conceptualization of the cause of SIB are discussed and it is proposed that the notion of a unitary cause of SIB is inappropriate. It is more productive to consider operant conditioning as the process that maintains responding against a background of predisposing and mediating factors which may be biologically determined.

  5. 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.

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

    OpenAIRE

    Yoshio Sakurai; Kichan Song

    2016-01-01

    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 cond...

  7. From Multi to Single Stack Automata

    Science.gov (United States)

    Atig, Mohamed Faouzi

    We investigate the issue of reducing the verification problem of multi-stack machines to the one for single-stack machines. For instance, elegant (and practically efficient) algorithms for bounded-context switch analysis of multi-pushdown systems have been recently defined based on reductions to the reachability problem of (single-stack) pushdown systems [10,18]. In this paper, we extend this view to both bounded-phase visibly pushdown automata (BVMPA) [16] and ordered multi-pushdown automata (OMPA) [1] by showing that each of their emptiness problem can be reduced to the one for a class of single-stack machines. For these reductions, we introduce effective generalized pushdown automata (EGPA) where operations on stacks are (1) pop the top symbol of the stack, and (2) push a word in some (effectively) given set of words L over the stack alphabet, assuming that L is in some class of languages for which checking whether L intersects regular languages is decidable. We show that the automata-based saturation procedure for computing the set of predecessors in standard pushdown automata can be extended to prove that for EGPA too the set of all predecessors of a regular set of configurations is an effectively constructible regular set. Our reductions from OMPA and BVMPA to EGPA, together with the reachability analysis procedure for EGPA, allow to provide conceptually simple algorithms for checking the emptiness problem for each of these models, and to significantly simplify the proofs for their 2ETIME upper bounds (matching their lower-bounds).

  8. Energy Expenditure of Sport Stacking

    Science.gov (United States)

    Murray, Steven R.; Udermann, Brian E.; Reineke, David M.; Battista, Rebecca A.

    2009-01-01

    Sport stacking is an activity taught in many physical education programs. The activity, although very popular, has been studied minimally, and the energy expenditure for sport stacking is unknown. Therefore, the purposes of this study were to determine the energy expenditure of sport stacking in elementary school children and to compare that value…

  9. OpenStack cloud security

    CERN Document Server

    Locati, Fabio Alessandro

    2015-01-01

    If you are an OpenStack administrator or developer, or wish to build solutions to protect your OpenStack environment, then this book is for you. Experience of Linux administration and familiarity with different OpenStack components is assumed.

  10. Vertically stacked nanocellulose tactile sensor.

    Science.gov (United States)

    Jung, Minhyun; Kim, Kyungkwan; Kim, Bumjin; Lee, Kwang-Jae; Kang, Jae-Wook; Jeon, Sanghun

    2017-11-16

    Paper-based electronic devices are attracting considerable attention, because the paper platform has unique attributes such as flexibility and eco-friendliness. Here we report on what is claimed to be the firstly fully integrated vertically-stacked nanocellulose-based tactile sensor, which is capable of simultaneously sensing temperature and pressure. The pressure and temperature sensors are operated using different principles and are stacked vertically, thereby minimizing the interference effect. For the pressure sensor, which utilizes the piezoresistance principle under pressure, the conducting electrode was inkjet printed on the TEMPO-oxidized-nanocellulose patterned with micro-sized pyramids, and the counter electrode was placed on the nanocellulose film. The pressure sensor has a high sensitivity over a wide range (500 Pa-3 kPa) and a high durability of 10 4 loading/unloading cycles. The temperature sensor combines various materials such as poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS), silver nanoparticles (AgNPs) and carbon nanotubes (CNTs) to form a thermocouple on the upper nanocellulose layer. The thermoelectric-based temperature sensors generate a thermoelectric voltage output of 1.7 mV for a temperature difference of 125 K. Our 5 × 5 tactile sensor arrays show a fast response, negligible interference, and durable sensing performance.

  11. Development and testing of a hybrid system with a sub-kW open-cathode type PEM (proton exchange membrane) fuel cell stack

    International Nuclear Information System (INIS)

    Huang, Zhen-Ming; Su, Ay; Liu, Ying-Chieh

    2014-01-01

    In this study, the performance of a polymer electrolyte membrane fuel cell stack has been evaluated for a hybrid power system test platform. To simulate vehicle acceleration, the stack was operated under dynamic-loading, and to demonstrate the exchange of power flow between two power sources the hybrid power system was tested under three different modes. A unit cell was fabricated for high stack performance and the stack was constructed with 18 open-cathode type fuel cells. Air which acts as a coolant as well as an oxidant for electrochemical reactions is provided by a pair of fans. The capabilities of the stack for hybrid power system test platform were validated by successful dynamic-loading tests. The performance of the stack for various air fan voltage was evaluated and an optimal value was concluded. The conditions like inlet temperature of H 2 and the stack current were established for maximum power. It was also found that humidification of hydrogen at anode inlet degrades the stack performance and stability due to flooding. Evidence shows that for the higher overall performance, the fuel cell acts continuously on constant current output. The study contributes to the design of mobility hybrid system to get better performance and reliability. - Highlights: • An open-cathode type PEMFC (polymer electrolyte membrane fuel cell) stack (rated output 300 W) was fabricated. • The open-cathode configuration simplifies the design of a stack system. • Assess the feasibility of combining a fuel cell stack in a hybrid system. • The study contributes to the design of mobility hybrid system to get better performance and reliability

  12. Progress of MCFC stack technology at Toshiba

    Energy Technology Data Exchange (ETDEWEB)

    Hori, M.; Hayashi, T.; Shimizu, Y. [Toshiba Corp., Tokyo (Japan)

    1996-12-31

    Toshiba is working on the development of MCFC stack technology; improvement of cell characteristics, and establishment of separator technology. For the cell technology, Toshiba has concentrated on both the restraints of NiO cathode dissolution and electrolyte loss from cells, which are the critical issues to extend cell life in MCFC, and great progress has been made. On the other hand, recognizing that the separator is one of key elements in accomplishing reliable and cost-competitive MCFC stacks, Toshiba has been accelerating the technology establishment and verification of an advanced type separator. A sub-scale stack with such a separator was provided for an electric generating test, and has been operated for more than 10,000 hours. This paper presents several topics obtained through the technical activities in the MCFC field at Toshiba.

  13. Lifting simulation of an offshore supply vessel considering various operating conditions

    OpenAIRE

    Dong-Hoon Jeong; Myung-Il Roh; Seung-Ho Ham

    2016-01-01

    Recently, an offshore support vessel is being widely used to install an offshore structure such as a subsea equipment which is laid on its deck. The lifting operation which is one of the installation operations includes lifting off, lifting in the air, splash zone crossing, deep submerging, and finally landing of the structure with an offshore support vessel crane. There are some major considerations during this operation. Especially, when lifting off the structure, if operating conditions su...

  14. Indicators for monitoring of safety operation and condition of nuclear power stations

    International Nuclear Information System (INIS)

    Manova, D.

    2001-01-01

    A common goal of all employees in the nuclear power field is safety operation of nuclear power stations. The evaluation and control of NPP safety operation are a part of the elements of safety management. The present report is related only to a part of the total assessment and control of the plant safety operation, namely - the indicator system for monitoring of Kozloduy NPP operation and condition. (author)

  15. 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...

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

    International Nuclear Information System (INIS)

    Kim, Sung Il; Park, Jong Hwa; Ha, Kwang Soon

    2015-01-01

    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

  17. 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.

  18. Stack Caching Using Split Data Caches

    DEFF Research Database (Denmark)

    Nielsen, Carsten; Schoeberl, Martin

    2015-01-01

    In most embedded and general purpose architectures, stack data and non-stack data is cached together, meaning that writing to or loading from the stack may expel non-stack data from the data cache. Manipulation of the stack has a different memory access pattern than that of non-stack data, showing...... higher temporal and spatial locality. We propose caching stack and non-stack data separately and develop four different stack caches that allow this separation without requiring compiler support. These are the simple, window, and prefilling with and without tag stack caches. The performance of the stack...

  19. Computer-Aided Design of Materials for use under High Temperature Operating Condition

    Energy Technology Data Exchange (ETDEWEB)

    Rajagopal, K. R.; Rao, I. J.

    2010-01-31

    The procedures in place for producing materials in order to optimize their performance with respect to creep characteristics, oxidation resistance, elevation of melting point, thermal and electrical conductivity and other thermal and electrical properties are essentially trial and error experimentation that tend to be tremendously time consuming and expensive. A computational approach has been developed that can replace the trial and error procedures in order that one can efficiently design and engineer materials based on the application in question can lead to enhanced performance of the material, significant decrease in costs and cut down the time necessary to produce such materials. The work has relevance to the design and manufacture of turbine blades operating at high operating temperature, development of armor and missiles heads; corrosion resistant tanks and containers, better conductors of electricity, and the numerous other applications that are envisaged for specially structured nanocrystalline solids. A robust thermodynamic framework is developed within which the computational approach is developed. The procedure takes into account microstructural features such as the dislocation density, lattice mismatch, stacking faults, volume fractions of inclusions, interfacial area, etc. A robust model for single crystal superalloys that takes into account the microstructure of the alloy within the context of a continuum model is developed. Having developed the model, we then implement in a computational scheme using the software ABAQUS/STANDARD. The results of the simulation are compared against experimental data in realistic geometries.

  20. 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...

  1. 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.

  2. 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)

  3. Operant Conditioning Principles in the Treatment of Learning and Behavior Problems with Delinquent Boys

    Science.gov (United States)

    Bednar, Richard L.; And Others

    1970-01-01

    This study on operant conditioning showed that both groups showed significant improvement in reading skills from pretest to posttest, but that the reinforced group showed significantly more improvement than the nonreinforced group. (Author)

  4. Stability and performance improvement of a polymer electrolyte membrane fuel cell stack by laser perforation of gas diffusion layers

    Energy Technology Data Exchange (ETDEWEB)

    Gerteisen, Dietmar; Sadeler, Christian [Fraunhofer Institute for Solar Energy Systems ISE, Department of Energy Technology, Heidenhofstrasse 2, 79110 Freiburg (Germany)

    2010-08-15

    The performance and stability of a hydrogen-driven polymer electrolyte membrane fuel cell stack (6-cell PEFC stack) are investigated with regard to pore flooding within the gas diffusion layers (GDLs). Two short stacks with various GDLs (Toray TGP-H-060 untreated and laser-perforated) were characterized at different operating conditions by several characterization techniques such as constant current load, polarization curve, chronoamperometry and chronovoltammetry. The experimental results reveal that the perforation of the cathode GDLs improves the water transport in the porous media and thus the performance as well as the stability of the operating stack in medium and high current density range. A reduced pore flooding is verified when using the customized laser-perforated GDLs. The GDL perforation has a huge potential to balance the inhomogeneous in-plane saturation conditions between the inlet and outlet area of the cell and to compensate to a certain degree the effects of temperature distribution within a stack regarding the water management. (author)

  5. Stability and performance improvement of a polymer electrolyte membrane fuel cell stack by laser perforation of gas diffusion layers

    Science.gov (United States)

    Gerteisen, Dietmar; Sadeler, Christian

    The performance and stability of a hydrogen-driven polymer electrolyte membrane fuel cell stack (6-cell PEFC stack) are investigated with regard to pore flooding within the gas diffusion layers (GDLs). Two short stacks with various GDLs (Toray TGP-H-060 untreated and laser-perforated) were characterized at different operating conditions by several characterization techniques such as constant current load, polarization curve, chronoamperometry and chronovoltammetry. The experimental results reveal that the perforation of the cathode GDLs improves the water transport in the porous media and thus the performance as well as the stability of the operating stack in medium and high current density range. A reduced pore flooding is verified when using the customized laser-perforated GDLs. The GDL perforation has a huge potential to balance the inhomogeneous in-plane saturation conditions between the inlet and outlet area of the cell and to compensate to a certain degree the effects of temperature distribution within a stack regarding the water management.

  6. Static analysis of worst-case stack cache behavior

    DEFF Research Database (Denmark)

    Jordan, Alexander; Brandner, Florian; Schoeberl, Martin

    2013-01-01

    Utilizing a stack cache in a real-time system can aid predictability by avoiding interference that heap memory traffic causes on the data cache. While loads and stores are guaranteed cache hits, explicit operations are responsible for managing the stack cache. The behavior of these operations can......-graph, the worst-case bounds can be efficiently yet precisely determined. Our evaluation using the MiBench benchmark suite shows that only 37% and 21% of potential stack cache operations actually store to and load from memory, respectively. Analysis times are modest, on average running between 0.46s and 1.30s per...... be analyzed statically. We present algorithms that derive worst-case bounds on the latency-inducing operations of the stack cache. Their results can be used by a static WCET tool. By breaking the analysis down into subproblems that solve intra-procedural data-flow analysis and path searches on the call...

  7. Schwarzian conditions for linear differential operators with selected differential Galois groups

    Science.gov (United States)

    Abdelaziz, Y.; Maillard, J.-M.

    2017-11-01

    We show that non-linear Schwarzian differential equations emerging from covariance symmetry conditions imposed on linear differential operators with hypergeometric function solutions can be generalized to arbitrary order linear differential operators with polynomial coefficients having selected differential Galois groups. For order three and order four linear differential operators we show that this pullback invariance up to conjugation eventually reduces to symmetric powers of an underlying order-two operator. We give, precisely, the conditions to have modular correspondences solutions for such Schwarzian differential equations, which was an open question in a previous paper. We analyze in detail a pullbacked hypergeometric example generalizing modular forms, that ushers a pullback invariance up to operator homomorphisms. We finally consider the more general problem of the equivalence of two different order-four linear differential Calabi-Yau operators up to pullbacks and conjugation, and clarify the cases where they have the same Yukawa couplings.

  8. Availability assessment of oil and gas processing plants operating under dynamic Arctic weather conditions

    OpenAIRE

    Naseri, Masoud; Baraldi, Piero; Compare, Michele; Zio, Enrico

    2016-01-01

    We consider the assessment of the availability of oil and gas processing facilities operating under Arctic conditions. The novelty of the work lies in modelling the time-dependent effects of environmental conditions on the components failure and repair rates. This is done by introducing weather-dependent multiplicative factors, which can be estimated by expert judgements given the scarce data available from Arctic offshore operations. System availability is assessed considering the equivalent...

  9. Public member dose assessment of Bushehr Nuclear Power Plant under normal operation by modeling the fallout from stack using the HYSPLIT atmospheric dispersion model.

    Science.gov (United States)

    Zali, A; Shamsaei Zafarghandi, M; Feghhi, S A; Taherian, A M

    2017-05-01

    In this work, public dose resulting from fission products released from Bushehr Nuclear Power Plant (BNPP) under normal operation is assessed. Due to the long range transport of radionuclides in this work (80 km) and considering terrain and meteorological data, HYbrid Single-Particle Lagrangian Integrated Trajectory (HYsplit) model, which uses three dimensional long-range numerical models, has been employed to calculate atmospheric dispersion. Annual effective dose calculation is carried out for inhalation, ingestion, and external exposure pathways in 16directions and within 80 km around the site for representative person. The results showed the maximum dose of inhalation and external exposure for adults is 3.8 × 10 -8 Sv/y in the SE direction and distance of 600 m from the BNPP site which is less than ICRP 103 recommended dose limit (1 mSv). Children and infants' doses are higher in comparison with adults, although they are less than 1 mSv. Ingestion dose percentage in the total dose is less than 0.1%. The results of this study underestimate the Final Safety Analysis Report ofBNPP-1 (FSAR)data. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Application of signature analysis for determining the operational readiness of motor-operated valves under blowdown test conditions

    International Nuclear Information System (INIS)

    Haynes, H.D.

    1988-01-01

    In support of the NRC-funded Nuclear Plant Aging Research (NPAR) program, Oak Ridge National Laboratory (ORNL) has carried out a comprehensive aging assessment of Motor-Operated Valves (MOVs). As part of this work, ORNL participated in the Gate Valve Flow Interruption Blowdown (GVFIB) tests carried out in Huntsville, Alabama. The GVFIB tests were intended primarily to determine the behavior of motor-operated gate valves under the temperature, pressure, and flow conditions expected to be experienced by isolation valves in Boiling Water Reactors (BWRs) during a high energy line break (blowdown) outside of containment. In addition, the tests provided an excellent opportunity to evaluate signature analysis methods for determining the operational readiness of the MOVs under those accident conditions. ORNL acquired motor current and torque switch shaft angular position data on two test MOVs during various times of the GVFIB tests. The reduction in operating ''margin'' of both MOVs due to the presence of additional valve running loads imposed by high flow was clearly observed in motor current and torque switch angular position signatures. In addition, the effects of differential pressure, fluid temperature, and line voltage on MOV operations were observed and more clearly understood as a result of utilizing signature analysis techniques. 1 ref.; 16 figs

  11. 49 CFR 236.528 - Restrictive condition resulting from open hand-operated switch; requirement.

    Science.gov (United States)

    2010-10-01

    ... SYSTEMS, DEVICES, AND APPLIANCES Automatic Train Stop, Train Control and Cab Signal Systems Rules and...-operated switch three-eighths inch or more, or hand-operated switch is not locked where facing point lock with circuit controller is used, the resultant restrictive condition of an automatic train stop or...

  12. 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…

  13. Substantial-Motivational Mechanism for Substantiation of Tolling Operations in Conditions of the European Integration

    OpenAIRE

    Melnyk Olga G; Kots Iryna I.

    2016-01-01

    The article is concerned with conceptualization of substance, distinguishing characteristics and motives of the implementation of tolling operations in conditions of the European integration. The study, based on the systematization and analysis of existing scientific approaches to definition of essence of tolling and tolling operations, has disclosed the dominating poli-positionality and ambiguity in this area. Economical autonomy of tolling operations has been determined, t...

  14. Passive stack ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, J.; Parkins, L.; Shaw, P.; Watkins, R. [Databuild, Birmingham (United Kingdom)

    1994-12-31

    The adequate ventilation of houses is essential for both the occupants and the building fabric. As air-tightness standards increase, background infiltration levels decrease and extra ventilation has to be designed into the building. Passive stack ventilation has many advantages - particularly when employed in low cost housing schemes -but it is essential that it performs satisfactorily. This paper give the results from monitoring two passive stack ventilation schemes. One scheme was a retrofit into refurbished local authority houses in which a package of energy efficiency measures had been taken and condensation had been a problem. The other series of tests were conducted on a new installation in a Housing Association development. Nine houses were monitored each of which had at least two passive vents. The results show air flow rates by the passive ducts equivalent to approximately 1 room air change per hour. The air flow in the ducts was influenced by both, internal to external temperature difference and wind speed and direction. (author)

  15. Asymmetric Flexible Supercapacitor Stack

    Directory of Open Access Journals (Sweden)

    Leela Mohana Reddy A

    2008-01-01

    Full Text Available AbstractElectrical double layer supercapacitor is very significant in the field of electrical energy storage which can be the solution for the current revolution in the electronic devices like mobile phones, camera flashes which needs flexible and miniaturized energy storage device with all non-aqueous components. The multiwalled carbon nanotubes (MWNTs have been synthesized by catalytic chemical vapor deposition technique over hydrogen decrepitated Mischmetal (Mm based AB3alloy hydride. The polymer dispersed MWNTs have been obtained by insitu polymerization and the metal oxide/MWNTs were synthesized by sol-gel method. Morphological characterizations of polymer dispersed MWNTs have been carried out using scanning electron microscopy (SEM, transmission electron microscopy (TEM and HRTEM. An assymetric double supercapacitor stack has been fabricated using polymer/MWNTs and metal oxide/MWNTs coated over flexible carbon fabric as electrodes and nafion®membrane as a solid electrolyte. Electrochemical performance of the supercapacitor stack has been investigated using cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy.

  16. The Methods of Design and Implementation of Stack Filters for Image Processing

    Directory of Open Access Journals (Sweden)

    S. Marchevsky

    1995-04-01

    Full Text Available This paper deals with a large class of nonlinear digital filters, the stack filters, which contain all combinations and compositions of rank order operators within a finite window. Attention is given to design and effective hardware implementation of an optimal stack filter for image processing. Presented simulation results confirm robustness of stack filters in the image restoration corrupted by impulsive noise.

  17. 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...

  18. Mapping of optimum operating condition for LiBr–water refrigeration ...

    Indian Academy of Sciences (India)

    These optimum condition maps will be useful to choose optimum operating conditions while designing LiBr–water cycle for desired applications. ... 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 ...

  19. 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…

  20. Instant BlueStacks

    CERN Document Server

    Judge, Gary

    2013-01-01

    Get to grips with a new technology, understand what it is and what it can do for you, and then get to work with the most important features and tasks. A fast-paced, example-based approach guide for learning BlueStacks.This book is for anyone with a Mac or PC who wants to run Android apps on their computer. Whether you want to play games that are freely available for Android but not your computer, or you want to try apps before you install them on a physical device or use it as a development tool, this book will show you how. No previous experience is needed as this is written in plain English

  1. Solid Oxide Cell and Stack Testing, Safety and Quality Assurance (SOCTESQA)

    DEFF Research Database (Denmark)

    Auer, C.; Lang, M.; Couturier, K.

    2015-01-01

    In the EU-funded project “SOCTESQA” partners from Europe and Singapore are working together to develop uniform and industry wide test procedures and protocols for solid oxide cells and stacks SOC cell/stack assembly. New application fields which are based on the operation of the SOC cell/stack as......In the EU-funded project “SOCTESQA” partners from Europe and Singapore are working together to develop uniform and industry wide test procedures and protocols for solid oxide cells and stacks SOC cell/stack assembly. New application fields which are based on the operation of the SOC cell...

  2. Non-negativity of conditional von Neumann entropy and global unitary operations

    Science.gov (United States)

    Patro, Subhasree; Chakrabarty, Indranil; Ganguly, Nirman

    2017-12-01

    Conditional von Neumann entropy is an intriguing concept in quantum information theory. In the present work, we examine the effect of global unitary operations on the conditional entropy of the system. We start with a set containing states with a non-negative conditional entropy and find that some states preserve the non-negativity under unitary operations on the composite system. We call this class of states the absolute conditional von Neumann entropy non-negative (ACVENN) class. We characterize such states for 2 ⊗2 -dimensional systems. From a different perspective the characterization accentuates the detection of states whose conditional entropy becomes negative after the global unitary action. Interestingly, we show that this ACVENN class of states forms a set which is convex and compact. This feature enables the existence of Hermitian witness operators. With these we can distinguish the unknown states which will have a negative conditional entropy after the global unitary operation. We also show that this has immediate application to superdense coding and state merging, as the negativity of the conditional entropy plays a key role in both these information processing tasks. Some illustrations followed by analysis are also provided to probe the connection of such states with absolutely separable states and absolutely local states.

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

    International Nuclear Information System (INIS)

    Jeong, Hae-Yong; Park, Moon-Ghu

    2015-01-01

    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

  4. Migration velocity analysis using pre-stack wave fields

    KAUST Repository

    Alkhalifah, Tariq Ali

    2016-08-25

    Using both image and data domains to perform velocity inversion can help us resolve the long and short wavelength components of the velocity model, usually in that order. This translates to integrating migration velocity analysis into full waveform inversion. The migration velocity analysis part of the inversion often requires computing extended images, which is expensive when using conventional methods. As a result, we use pre-stack wavefield (the double-square-root formulation) extrapolation, which includes the extended information (subsurface offsets) naturally, to make the process far more efficient and stable. The combination of the forward and adjoint pre-stack wavefields provides us with update options that can be easily conditioned to improve convergence. We specifically use a modified differential semblance operator to split the extended image into a residual part for classic differential semblance operator updates and the image (Born) modelling part, which provides reflections for higher resolution information. In our implementation, we invert for the velocity and the image simultaneously through a dual objective function. Applications to synthetic examples demonstrate the features of the approach.

  5. 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)

  6. 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.

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

    International Nuclear Information System (INIS)

    Strączkiewicz, M; Barszcz, T; Jabłoński, A

    2015-01-01

    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. (paper)

  8. Maintaining reduced noise levels in a resource-constrained neonatal intensive care unit by operant conditioning.

    Science.gov (United States)

    Ramesh, A; Denzil, S B; Linda, R; Josephine, P K; Nagapoornima, M; Suman Rao, P N; Swarna Rekha, A

    2013-03-01

    To evaluate the efficacy of operant conditioning in sustaining reduced noise levels in the neonatal intensive care unit (NICU). Quasi-experimental study on quality of care. Level III NICU of a teaching hospital in south India. 26 staff employed in the NICU. (7 Doctors, 13 Nursing staff and 6 Nursing assistants). Operant conditioning of staff activity for 6 months. This method involves positive and negative reinforcement to condition the staff to modify noise generating activities. Comparing noise levels in decibel: A weighted [dB (A)] before conditioning with levels at 18 and 24 months after conditioning. Decibel: A weighted accounts for noise that is audible to human ears. Operant conditioning for 6 months sustains the reduced noise levels to within 62 dB in ventilator room 95% CI: 60.4 - 62.2 and isolation room (95% CI: 55.8 - 61.5). In the preterm room, noise can be maintained within 52 dB (95% CI: 50.8 - 52.6). This effect is statistically significant in all the rooms at 18 months (P = 0.001). At 24 months post conditioning there is a significant rebound of noise levels by 8.6, 6.7 and 9.9 dB in the ventilator, isolation and preterm room, respectively (P =0.001). Operant conditioning for 6 months was effective in sustaining reduced noise levels. At 18 months post conditioning, the noise levels were maintained within 62 dB (A), 60 dB (A) and 52 dB (A) in the ventilator, isolation and pre-term room, respectively. Conditioning needs to be repeated at 12 months in the ventilator room and at 18 months in the other rooms.

  9. Condition Monitoring for Roller Bearings of Wind Turbines Based on Health Evaluation under Variable Operating States

    Directory of Open Access Journals (Sweden)

    Lei Fu

    2017-10-01

    Full Text Available Condition monitoring (CM is used to assess the health status of wind turbines (WT by detecting turbine failure and predicting maintenance needs. However, fluctuating operating conditions cause variations in monitored features, therefore increasing the difficulty of CM, for example, the frequency-domain analysis may lead to an inaccurate or even incorrect prediction when evaluating the health of the WT components. In light of this challenge, this paper proposed a method for the health evaluation of WT components based on vibration signals. The proposed approach aimed to reduce the evaluation error caused by the impact of the variable operating condition. First, the vibration signal was decomposed into a set of sub-signals using variational mode decomposition (VMD. Next, the sub-signal energy and the probability distribution were obtained and normalized. Finally, the concept of entropy was introduced to evaluate the health condition of a monitored object to provide an effective guide for maintenance. In particular, the health evaluation for CM was based on a performance review over a range of operating conditions, rather than at a certain single operating condition. Experimental investigations were performed which verified the efficiency of the evaluation method, as well as a comparison with the previous method.

  10. Assessing Elementary Algebra with STACK

    Science.gov (United States)

    Sangwin, Christopher J.

    2007-01-01

    This paper concerns computer aided assessment (CAA) of mathematics in which a computer algebra system (CAS) is used to help assess students' responses to elementary algebra questions. Using a methodology of documentary analysis, we examine what is taught in elementary algebra. The STACK CAA system, http://www.stack.bham.ac.uk/, which uses the CAS…

  11. HPC Software Stack Testing Framework

    Energy Technology Data Exchange (ETDEWEB)

    2017-07-27

    The HPC Software stack testing framework (hpcswtest) is used in the INL Scientific Computing Department to test the basic sanity and integrity of the HPC Software stack (Compilers, MPI, Numerical libraries and Applications) and to quickly discover hard failures, and as a by-product it will indirectly check the HPC infrastructure (network, PBS and licensing servers).

  12. Influence of wastewater treatment plants' operational conditions on activated sludge microbiological and morphological characteristics.

    Science.gov (United States)

    Amanatidou, Elisavet; Samiotis, Georgios; Trikoilidou, Eleni; Tzelios, Dimitrios; Michailidis, Avraam

    2016-01-01

    The effect of wastewater composition and operating conditions in activated sludge (AS) microbiological and morphological characteristics was studied in three AS wastewater treatment plants (WWTPs): (a) a high organic load slaughterhouse AS WWTP, operating at complete solids retention, monitored from its start-up and for 425 days; (b) a seasonally operational, low nitrogen load fruit canning industry AS WWTP, operating at complete solids retention, monitored from its start-up and until the end of the season (87 days); (c) a municipal AS WWTP, treating wastewater from a semi-combined sewer system, monitored during the transitions from dry to rainy and again to dry periods of operation. The sludge microbiological and morphological characteristics were correlated to nutrients' availability, solids retention time, hydraulic retention time, dissolved oxygen, mixed liquor suspended solids (MLVSS), organic load (F/M) and substrate utilization rate. The AS WWTPs' operation was distinguished in periods based on biomass growth phase, characterized by different biological and morphological characteristics and on operational conditions. An anoxic/aerobic selector minimizes the readily biodegradable compounds in influent, inhibiting filamentous growth. Plant performance controlling is presented in a logic flowchart in which operational parameters are linked to microbial manipulation, resulting in a useful tool for researchers and engineers.

  13. Substantial-Motivational Mechanism for Substantiation of Tolling Operations in Conditions of the European Integration

    Directory of Open Access Journals (Sweden)

    Melnyk Olga G

    2016-02-01

    Full Text Available The article is concerned with conceptualization of substance, distinguishing characteristics and motives of the implementation of tolling operations in conditions of the European integration. The study, based on the systematization and analysis of existing scientific approaches to definition of essence of tolling and tolling operations, has disclosed the dominating poli-positionality and ambiguity in this area. Economical autonomy of tolling operations has been determined, their difference from the operations with customerfurnished raw materials has been allocated, substance and characteristics of tolling operations has been conceptually grounded, motives of their implementation for both the customer and the provider has been systematized. It is proved that implementation of tolling operations will address the pivotal financial, production and staffing problems of domestic enterprises and ensure their progressive development in conditions of the European integration. Prospect of further research is developing a conceptual framework for management of tolling operations, which will provide targeted exposure of management system on the controlled system, which is directly involved in the implementation of tolling operations, with a view to enhancing the efficiency of tolling process

  14. 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.

  15. Towards artificial intelligence based diesel engine performance control under varying operating conditions using support vector regression

    Directory of Open Access Journals (Sweden)

    Naradasu Kumar Ravi

    2013-01-01

    Full Text Available Diesel engine designers are constantly on the look-out for performance enhancement through efficient control of operating parameters. In this paper, the concept of an intelligent engine control system is proposed that seeks to ensure optimized performance under varying operating conditions. The concept is based on arriving at the optimum engine operating parameters to ensure the desired output in terms of efficiency. In addition, a Support Vector Machines based prediction model has been developed to predict the engine performance under varying operating conditions. Experiments were carried out at varying loads, compression ratios and amounts of exhaust gas recirculation using a variable compression ratio diesel engine for data acquisition. It was observed that the SVM model was able to predict the engine performance accurately.

  16. Photovoltaic module and array performance characterization methods for all system operating conditions

    Energy Technology Data Exchange (ETDEWEB)

    King, D.L.

    1996-12-31

    This paper provides new test methods and analytical procedures for characterizing the electrical performance of photovoltaic modules and arrays. The methods use outdoor measurements to provide performance parameters both at standard reporting conditions and for all operating conditions encountered by typical photovoltaic systems. Improvements over previously used test methods are identified, and examples of the successful application of the methodology are provided for crystalline- and amorphous-silicon modules and arrays. This work provides an improved understanding of module and array performance characteristics, and perhaps most importantly, a straight- forward yet rigorous model for predicting array performance at all operating conditions. For the first time, the influences of solar irradiance, operating temperature, solar spectrum, solar angle-of- incidence, and temperature coefficients are all addressed in a practical way that will benefit both designers and users of photovoltaics.

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

    International Nuclear Information System (INIS)

    Baraldi, Piero; Razavi-Far, Roozbeh; Zio, Enrico

    2011-01-01

    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.

  18. AC impedance diagnosis of a 500 W PEM fuel cell stack . Part I: Stack impedance

    Science.gov (United States)

    Yuan, Xiaozi; Sun, Jian Colin; Blanco, Mauricio; Wang, Haijiang; Zhang, Jiujun; Wilkinson, David P.

    Diagnosis of stack performance is of importance to proton exchange membrane (PEM) fuel cell research. This paper presents the diagnostic testing results of a 500 W Ballard Mark V PEM fuel cell stack with an active area of 280 cm 2 by electrochemical impedance spectroscopy (EIS). The EIS was measured using a combination of a FuelCon test station, a TDI loadbank, and a Solartron 1260 Impedance/Gain-Phase Analyzer operating in the galvanostatic mode. The method described in this work can obtain the impedance spectra of fuel cells with a larger geometric surface area and power, which are normally difficult to measure due to the limitations on commercial load banks operating at high currents. By using this method, the effects of temperature, flow rate, and humidity on the stack impedance spectra were examined. The results of the electrochemical impedance analysis show that with increasing temperature, the charge transfer resistance decreases due to the slow oxygen reduction reaction (ORR) process at low temperature. If the stack is operated at a fixed air flow rate, a low frequency arc appears and grows with increasing current due to the shortage of air. The anode humidification cut-off does not affect the spectra compared to the cut-off for cathode humidification.

  19. Teaching giant african pouched rats to find landmines: operant conditioning with real consequences.

    Science.gov (United States)

    Poling, Alan; Weetjens, Bart J; Cox, Christophe; Beyene, Negussie; Bach, Håvard; Sully, Andrew

    2010-01-01

    Giant African pouched rats recently have been used as mine-detection animals in Mozambique. To provide an example of the wide range of problems to which operant conditioning procedures can be applied and to illustrate the common challenges often faced in applying those procedures, this manuscript briefly describes how the rats are trained and used operationally. To date, the rats have performed well and it appears they can play a valuable role in humanitarian demining.

  20. Effects of cathode channel size and operating conditions on the performance of air-blowing PEMFCs

    International Nuclear Information System (INIS)

    Kim, Bosung; Lee, Yongtaek; Woo, Ahyoung; Kim, Yongchan

    2013-01-01

    Highlights: • Effect of cathode channel size on the air-blowing PEMFC is analyzed. • Performance and EIS tests of air-blowing PEMFCs are conducted. • Test conditions include the operating temperature, fan voltage, and anode humidity. • Flooding is a limiting factor for decreasing channel size at low temperature. • Water management is investigated by analyzing ohmic resistance. - Abstract: Air-blowing proton exchange membrane fuel cells (PEMFCs) have been developed as a potential new power source for portable electronic devices. However, air-blowing PEMFCs show lower performance than compressed-air PEMFCs because of their adverse operating conditions. In this study, the effects of the cathode channel size and operating conditions on the performance of the air-blowing PEMFC were analyzed. At the normal operating temperature, the performance of the air-blowing PEMFC improved with the decrease in the cathode channel size. However, at a low operating temperature and low fan voltage, massive flooding limits the decrease in the cathode channel size. In addition, water management in the air-blowing PEMFC was investigated by analyzing ohmic resistance. The transition current density between the humidification and the flooding region decreased with decreasing cathode channel size and operating temperature

  1. Lifting simulation of an offshore supply vessel considering various operating conditions

    Directory of Open Access Journals (Sweden)

    Dong-Hoon Jeong

    2016-06-01

    Full Text Available Recently, an offshore support vessel is being widely used to install an offshore structure such as a subsea equipment which is laid on its deck. The lifting operation which is one of the installation operations includes lifting off, lifting in the air, splash zone crossing, deep submerging, and finally landing of the structure with an offshore support vessel crane. There are some major considerations during this operation. Especially, when lifting off the structure, if operating conditions such as ocean environmental loads and hoisting (or lowering speed are bad, the excess of tension of wire ropes of the crane and the collision between the offshore support vessel and the structure can be occurred due to the relative motion between them. To solve this problem, this study performs the lifting simulation while the offshore support vessel installs the structure. The simulation includes the calculation of dynamic responses of the offshore support vessel and the equipment, including the wire tension and the collision detection. To check the applicability of the simulation, it is applied to some lifting steps by varying operating conditions. As a result, it is confirmed that the conditions affect the operability of those steps.

  2. THE IMPACT OF PROGRESSIVE GEAR GEOMETRY ON THE BRAKING DISTANCE LENGTH UNDER CHANGEABLE OPERATING CONDITIONS

    Directory of Open Access Journals (Sweden)

    Paweł Lonkwic

    2016-03-01

    Full Text Available This article presents independent tests results focused on the geometry impact of progressive gear used in a short distance transportation devices on the braking distance length both under changeable operating conditions as well as changeable loading. Variable operating conditions were obtained with the use of various lubricating agents. Five types of gears such as ASG100, PP16, PR2000, KB160 and a new solution CHP2000 were used for the tests. The tests were conducted with a free fall method application. The method gave a chance to evaluate reliability of tested gears systems and to compare the existing solutions with the proposed gear of CHP2000 type.

  3. 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.

  4. 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.

  5. 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...

  6. Damage detection under varying environmental and operational conditions using Wavelet Transform Modulus Maxima decay lines similarity

    Science.gov (United States)

    Tjirkallis, A.; Kyprianou, A.

    2016-01-01

    Over the last three decades, there have been increasing demands to develop and deploy Structural Health Monitoring (SHM) systems for engineering structures in service. Since these structures are subjected to varying environmental and operational conditions, reliable SHM methodologies must be capable of not misattributing to damage changes due to environmental conditions. This paper presents a novel damage detection methodology based on the similarity between maxima decay lines of the continuous wavelet transform scalogram of the structural responses obtained under different operational and environmental conditions. The normalized cross correlation (NCC) is used as a measure of this similarity. In addition, the pointwise summation of similar Wavelet Transform Modulus Maxima (WTMM) decay lines is used to identify changes due to the presence of damage from different force realizations and/or varying environmental conditions. The effectiveness of the proposed methodology is demonstrated using a simulated 3DOF system and an experimental cantilever beam.

  7. Operational optimization of networks of compressors considering condition-based maintenance

    OpenAIRE

    Xenos, DP; Kopanos, GM; Cicciotti, M; Thornhill, NF

    2015-01-01

    The paper presents a mixed integer linear programming model which deals with the optimal operation and maintenance of networks of compressors of chemical plants. This optimization model considers condition-based maintenance which involves the degradation of the condition of the compressors. The paper focuses on online and offline washing, two different cleaning procedures which reduce the extra power used by the compressors due to fouling. The state-of-the-art has demonstrated the optimal sch...

  8. Exploration of robust operating conditions in inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Tromp, John W.; Pomares, Mario; Alvarez-Prieto, Manuel; Cole, Amanda; Ying Hai; Salin, Eric D.

    2003-01-01

    'Robust' conditions, as defined by Mermet and co-workers for inductively coupled plasma (ICP)-atomic emission spectrometry, minimize matrix effects on analyte signals, and are obtained by increasing power and reducing nebulizer gas flow. In ICP-mass spectrometry (MS), it is known that reduced nebulizer gas flow usually leads to more robust conditions such that matrix effects are reduced. In this work, robust conditions for ICP-MS have been determined by optimizing for accuracy in the determination of analytes in a multi-element solution with various interferents (Al, Ba, Cs, K, Na), by varying power, nebulizer gas flow, sample introduction rate and ion lens voltage. The goal of the work was to determine which operating parameters were the most important in reducing matrix effects, and whether different interferents yielded the same robust conditions. Reduction in nebulizer gas flow and in sample input rate led to a significantly decreased interference, while an increase in power seemed to have a lesser effect. Once the other parameters had been adjusted to their robust values, there was no additional improvement in accuracy attainable by adjusting the ion lens voltage. The robust conditions were universal, since, for all the interferents and analytes studied, the optimum was found at the same operating conditions. One drawback to the use of robust conditions was the slightly reduced sensitivity; however, in the context of 'intelligent' instruments, the concept of 'robust conditions' is useful in many cases

  9. 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...

  10. Optimal Start-Up and Operation Policy for an Ultrafiltration Membrane Unit in Whey Separation The work presented here is generated by the Institute for Sustainable Process Technology (ISPT) project IMPROVISE

    NARCIS (Netherlands)

    Bahadir Saltik, M.; Özkan, Leyla; Jacobs, Marc; Padt, van der Albert

    2016-01-01

    Membrane filtration systems are preferred unit operations in industrial applications due to their mild operating conditions. However the performance of a membrane stack drops over time because of the membrane fouling. This decrease is overcomed by introducing clean membrane stacks. The associated

  11. National Spherical Torus Experiment (NSTX) Center Stack Upgrade

    International Nuclear Information System (INIS)

    Neumeyer, C.; Avasarala, S.; Chrzanowski, J.; Dudek, L.; Fan, H.; Hatcher, H.; Heitzenroeder, P.; Menard, J.; Ono, M.; Ramakrishnan, S.; Titus, P.; Woolley, R.; Zhan, H.

    2009-01-01

    The purpose of the NSTX Center Stack Upgrade project is to expand the NSTX operational space and thereby the physics basis for next-step ST facilities. The plasma aspect ratio (ratio of plasma major to minor radius) of the upgrade is increased to 1.5 from the original value of 1.26, which increases the cross sectional area of the center stack by a factor of ∼ 3 and makes possible higher levels of performance and pulse duration.

  12. Environmental assessment of phosphogypsum stacks

    International Nuclear Information System (INIS)

    Odat, M.; Al-Attar, L.; Raja, G.; Abdul Ghany, B.

    2008-03-01

    Phosphogypsum is one of the most important by-products of phosphate fertilizer industry. It is kept in large stacks to the west of Homs city. Storing Phosphogypsum as open stacks exposed to various environmental effects, wind and rain, may cause pollution of the surrounding ecosystem (soil, plant, water and air). This study was carried out in order to assess the environmental impact of Phosphogypsum stacks on the surrounding ecosystem. The obtained results show that Phosphogypsum stacks did not increase the concentration of radionuclides, i.e. Radon-222 and Radium-226, the external exposed dose of gamma rays, as well as the concentration of heavy metals in the components of the ecosystem, soil, plant, water and air, as their concentrations did not exceed the permissible limits. However, the concentration of fluorine in the upper layer of soil, located to the east of the Phosphogypsum stacks, increased sufficiently, especially in the dry period of the year. Also, the concentration of fluoride in plants growing up near-by the Phosphogypsum stacks was too high, exceeded the permissible levels. This was reflected in poising plants and animals, feeding on the plants. Consequently, increasing the concentration of fluoride in soil and plants is the main impact of Phosphogypsum stacks on the surrounding ecosystem. Minimising this effect could be achieved by establishing a 50 meter wide protection zone surrounding the Phosphogypsum stacks, which has to be planted with non palatable trees, such as pine and cypress, forming wind barriers. Increasing the concentrations of heavy metals and fluoride in infiltrated water around the stacks was high; hence cautions must be taken to prevent its usage in any application or disposal in adjacent rivers and leaks.(author)

  13. Characterization of a thermoelectric cooler based thermal management system under different operating conditions

    International Nuclear Information System (INIS)

    Russel, M.K.; Ewing, D.; Ching, C.Y.

    2013-01-01

    The performance of a thermoelectric cooler (TEC) based thermal management system for an electronic packaging design that operates under a range of ambient conditions and system loads is examined using a standard model for the TEC and a thermal resistance network for the other components. Experiments were performed and it was found that the model predictions were in good agreement with the experimental results. An operating envelope is developed to characterize the TEC based thermal management system for peak and off peak operating conditions. Parametric studies were performed to analyze the effect of the number of TEC module(s) in the system, geometric factor of the thermo-elements and the cold to hot side thermal resistances on the system performance. The results showed that there is a tradeoff between the extent of off peak heat fluxes and ambient temperatures when the system can be operated at a low power penalty region and the maximum capacity of the system. - Highlights: ► A model was developed for thermal management systems using thermoelectric coolers. ► Model predictions were in good agreement with experimental results. ► An operating envelope was developed for peak and off peak conditions. ► The effect of the number of thermoelectric coolers on the system was determined.

  14. Modeling of the Human - Operator in a Complex System Functioning Under Extreme Conditions

    Science.gov (United States)

    Getzov, Peter; Hubenova, Zoia; Yordanov, Dimitar; Popov, Wiliam

    2013-12-01

    Problems, related to the explication of sophisticated control systems of objects, operating under extreme conditions, have been examined and the impact of the effectiveness of the operator's activity on the systems as a whole. The necessity of creation of complex simulation models, reflecting operator's activity, is discussed. Organizational and technical system of an unmanned aviation complex is described as a sophisticated ergatic system. Computer realization of main subsystems of algorithmic system of the man as a controlling system is implemented and specialized software for data processing and analysis is developed. An original computer model of a Man as a tracking system has been implemented. Model of unmanned complex for operators training and formation of a mental model in emergency situation, implemented in "matlab-simulink" environment, has been synthesized. As a unit of the control loop, the pilot (operator) is simplified viewed as an autocontrol system consisting of three main interconnected subsystems: sensitive organs (perception sensors); central nervous system; executive organs (muscles of the arms, legs, back). Theoretical-data model of prediction the level of operator's information load in ergatic systems is proposed. It allows the assessment and prediction of the effectiveness of a real working operator. Simulation model of operator's activity in takeoff based on the Petri nets has been synthesized.

  15. Evaluation of Next Generation Nuclear Power Plant (NGNP) Intermediate Heat Exchanger (IHX) Operating Conditions

    Energy Technology Data Exchange (ETDEWEB)

    E. A. Harvego

    2006-04-01

    This report summarizes results of a preliminary evaluation to determine the operating conditions for the Next Generation Nuclear Plant (NGNP) Intermediate Heat Exchanger (IHX) that will transfer heat from the reactor primary system to the demonstration hydrogen production plant(s). The Department of Energy is currently investigating two primary options for the production of hydrogen using a high temperature reactor as the power source. These options are the High Temperature Electrolysis (HTE) and Sulfur-Iodine (SI) thermochemical hydrogen production processes. However, since the SI process relies entirely on process heat from the reactor, while the HTE process relies primarily on electrical energy with only a small amount of process heat required, the design of the IHX is dictated by the SI process heat requirements. Therefore, the IHX operating conditions were defined assuming 50 MWt is available for the production of hydrogen using the SI process. Three configurations for the intermediate loop were evaluated, including configurations for both direct and indirect power conversion systems. The HYSYS process analysis software was used to perform sensitivity studies to determine the influence of reactor outlet temperatures, intermediate loop working fluids (helium and molten salt), intermediate loop pressures, and intermediate loop piping lengths on NGNP performance and IHX operating conditions. The evaluation of NGNP performance included assessments of overall electric power conversion efficiency and estimated hydrogen production efficiency. Based on these evaluations, recommended IHX operating conditions are defined.

  16. 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

    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...

  17. 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

  18. [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.

  19. Effect of operating conditions on thin layers of titanium posed on ...

    African Journals Online (AJOL)

    Effect of operating conditions on thin layers of titanium posed on steel 100C6 substrates with PVD method. ... Journal of Fundamental and Applied Sciences ... reaction between the two parts of the system which results the formation of carbides of Ti due to the diffusion of carbon from the substrate towards deposited layers.

  20. 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...

  1. 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

  2. Self-Injurious Behavior in Rett Syndrome: Interactions between Features of Rett Syndrome and Operant Conditioning.

    Science.gov (United States)

    Oliver, Chris; And Others

    1993-01-01

    In this case study, interactions were examined between features of Rett syndrome and operant conditioning as determinants of self-injurious behavior (SIB). Analysis suggested different functions for two forms of SIB: automatic reinforcement by sensory stimulation and escape from social interactions. Features of Rett syndrome tended to maximize the…

  3. 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

  4. 42 CFR 433.130 - Waiver of conditions of initial operation and approval.

    Science.gov (United States)

    2010-10-01

    ... Claims Processing and Information Retrieval Systems § 433.130 Waiver of conditions of initial operation... system will not significantly improve the efficiency of the administration of the State plan. (c) If CMS... waiver, that a system would significantly improve the administration of the State Medicaid program, CMS...

  5. 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

    characterization tests performed for a wide range of operating conditions (temperature, load current and state-of-charge) 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...

  6. Industrial stacks design; Diseno de chimeneas industriales

    Energy Technology Data Exchange (ETDEWEB)

    Cacheux, Luis [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1986-12-31

    The Instituto de Investigaciones Electricas (IIE) though its Civil Works Department, develops, under contract with CFE`s Gerencia de Proyectos Termoelectricos (Management of Fossil Power Plant Projects), a series of methods for the design of stacks, which pretends to solve the a present day problem: the stack design of the fossil power plants that will go into operation during the next coming years in the country. [Espanol] El Instituto de Investigaciones Electricas (IIE), a traves del Departamento de Ingenieria Civil, desarrolla, bajo contrato con la Gerencia de Proyectos Termoelectricos, de la Comision Federal de Electricidad (CFE), un conjunto de metodos para el diseno de chimeneas, con el que se pretende resolver un problema inmediato: el diseno de las chimeneas de las centrales termoelectricas que entraran en operacion durante los proximos anos, en el pais.

  7. Annular feed air breathing fuel cell stack

    Science.gov (United States)

    Wilson, Mahlon S.

    1996-01-01

    A stack of polymer electrolyte fuel cells is formed from a plurality of unit cells where each unit cell includes fuel cell components defining a periphery and distributed along a common axis, where the fuel cell components include a polymer electrolyte membrane, an anode and a cathode contacting opposite sides of the membrane, and fuel and oxygen flow fields contacting the anode and the cathode, respectively, wherein the components define an annular region therethrough along the axis. A fuel distribution manifold within the annular region is connected to deliver fuel to the fuel flow field in each of the unit cells. In a particular embodiment, a single bolt through the annular region clamps the unit cells together. In another embodiment, separator plates between individual unit cells have an extended radial dimension to function as cooling fins for maintaining the operating temperature of the fuel cell stack.

  8. Combining parametric, semi-parametric, and non-parametric survival models with stacked survival models.

    Science.gov (United States)

    Wey, Andrew; Connett, John; Rudser, Kyle

    2015-07-01

    For estimating conditional survival functions, non-parametric estimators can be preferred to parametric and semi-parametric estimators due to relaxed assumptions that enable robust estimation. Yet, even when misspecified, parametric and semi-parametric estimators can possess better operating characteristics in small sample sizes due to smaller variance than non-parametric estimators. Fundamentally, this is a bias-variance trade-off situation in that the sample size is not large enough to take advantage of the low bias of non-parametric estimation. Stacked survival models estimate an optimally weighted combination of models that can span parametric, semi-parametric, and non-parametric models by minimizing prediction error. An extensive simulation study demonstrates that stacked survival models consistently perform well across a wide range of scenarios by adaptively balancing the strengths and weaknesses of individual candidate survival models. In addition, stacked survival models perform as well as or better than the model selected through cross-validation. Finally, stacked survival models are applied to a well-known German breast cancer study. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  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. 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....... has the capacity to retain the uncertainties of met-ocean condition forecasting and transfer them into uncertainties of probability of operation failure. In addition to that, improvements to the failure function, used to define operation failure are presented. The failure function is modified...

  11. 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.

  12. Experimental and simulational study of the operation conditions for a high transmission mass filter

    International Nuclear Information System (INIS)

    Ayesh, A. I.; Lassesson, A.; Brown, S. A.; Dunbar, A. D. F.; Kaufmann, M.; Partridge, J. G.; Reichel, R.; Lith, J. van

    2007-01-01

    The operation conditions of a double pulsed field mass filter were studied using both experiment and simulation. The mass filter consists of two pairs of parallel plates and operates on the time-of-flight principle. The study showed that the ions' beam deflection angle is a critical factor in optimizing the mass filter transmission efficiency. This angle is dependent on the accelerating voltage, ion mass, and horizontal velocity of the ions. The optimum operating conditions for the mass filter were found and used to study the mass distribution of palladium ions produced by a magnetron sputtering source. The study shows that this mass filter is suitable for technological applications because of its high transmission and wide mass range

  13. 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.

  14. ORELA data acquisition system hardware. Vol. 6. Eight-stage stacking buffer memory (Q-5066)

    International Nuclear Information System (INIS)

    Wintenberg, R.E.; Reynolds, J.W.

    1977-01-01

    A Stacking Buffer Memory for de-randomizing data on high data rate experiments at ORELA is documented by a description of operation, mechanical details of design, and a detailed theory of operation illustrated through six examples of operation

  15. Mixed Mechanism of Lubrication by Lipid Bilayer Stacks.

    Science.gov (United States)

    Boţan, Alexandru; Joly, Laurent; Fillot, Nicolas; Loison, Claire

    2015-11-10

    Although the key role of lipid bilayer stacks in biological lubrication is generally accepted, the mechanisms underlying their extreme efficiency remain elusive. In this article, we report molecular dynamics simulations of lipid bilayer stacks undergoing load and shear. When the hydration level is reduced, the velocity accommodation mechanism changes from viscous shear in hydration water to interlayer sliding in the bilayers. This enables stacks of hydrated lipid bilayers to act as efficient boundary lubricants for various hydration conditions, structures, and mechanical loads. We also propose an estimation for the friction coefficient; thanks to the strong hydration forces between lipid bilayers, the high local viscosity is not in contradiction with low friction coefficients.

  16. PieceStack: Toward Better Understanding of Stacked Graphs.

    Science.gov (United States)

    Wu, Tongshuang; Wu, Yingcai; Shi, Conglei; Qu, Huamin; Cui, Weiwei

    2016-02-24

    Stacked graphs have been widely adopted in various fields, because they are capable of hierarchically visualizing a set of temporal sequences as well as their aggregation. However, because of visual illusion issues, connections between overly-detailed individual layers and overly-generalized aggregation are intercepted. Consequently, information in this area has yet to be fully excavated. Thus, we present PieceStack in this paper, to reveal the relevance of stacked graphs in understanding intrinsic details of their displayed shapes. This new visual analytic design interprets the ways through which aggregations are generated with individual layers by interactively splitting and re-constructing the stacked graphs. A clustering algorithm is designed to partition stacked graphs into sub-aggregated pieces based on trend similarities of layers. We then visualize the pieces with augmented encoding to help analysts decompose and explore the graphs with respect to their interests. Case studies and a user study are conducted to demonstrate the usefulness of our technique in understanding the formation of stacked graphs.

  17. Evaluation of performance enhancement by condensing the anode moisture in a proton exchange membrane fuel cell stack

    International Nuclear Information System (INIS)

    Zhang, Shouzhen; Chen, Ben; Shu, Peng; Luo, Maji; Xie, Changjun; Quan, Shuhai; Tu, Zhengkai; Yu, Yi

    2017-01-01

    Highlights: • Anode Moisture condensing is introduced into a PEMFC stack. • Performance improves at high current density and high stack temperature after AMC. • MEA is dehydrated and poor performance occurs at low current density during AMC. - Abstract: Water management is an important issue for proton exchange membrane fuel cells. Back-diffusion of water from cathode to anode often occurs due to the differences in concentration and pressure during operation of fuel cell, resulting in the flooding and severe carbon corrosion in the cathode. Herein, we report a novel method of anode moisture condensing (AMC) in which a condenser is set at the outlet of the anode to cool down the anode moisture. With the help of AMC, liquid water is condensed from the moisture due to the variation of the saturated pressure of water vapor, which can accelerate the evaporating of the liquid water inside the anode and mitigate the probability of water flooding. A ten-cell stack with a condenser at the outlet of the anode is fabricated to systematically investigate the effects of the stack temperature and flow rate on the stack performance. The result shows that the PEMFC performance can be greatly improved at high current density and high operation temperature under the condition of AMC. The stack exhibits very similar performance before and after application of AMC below 500 mA cm −2 , whereas the output power increases from 405 W to 436 W at 600 mA cm −2 at 65 °C. With further increase in operation temperature to 80 °C, the average voltage increases from 0.598 V to 0.641 V even at 500 mA cm −2 . Moreover, the application of AMC can speed up the water evaporation, leading to the dehydration of the membrane and thus poor performance of PEMFC at low current density.

  18. Final Report - MEA and Stack Durability for PEM Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Yandrasits, Michael A.

    2008-02-15

    Proton exchange membrane fuel cells are expected to change the landscape of power generation over the next ten years. For this to be realized one of the most significant challenges to be met for stationary systems is lifetime, where 40,000 hours of operation with less than 10% decay is desired. This project conducted fundamental studies on the durability of membrane electrode assemblies (MEAs) and fuel cell stack systems with the expectation that knowledge gained from this project will be applied toward the design and manufacture of MEAs and stack systems to meet DOE’s 2010 stationary fuel cell stack systems targets. The focus of this project was PEM fuel cell durability – understanding the issues that limit MEA and fuel cell system lifetime, developing mitigation strategies to address the lifetime issues and demonstration of the effectiveness of the mitigation strategies by system testing. To that end, several discoveries were made that contributed to the fundamental understanding of MEA degradation mechanisms. (1) The classically held belief that membrane degradation is solely due to end-group “unzipping” is incorrect; there are other functional groups present in the ionomer that are susceptible to chemical attack. (2) The rate of membrane degradation can be greatly slowed or possibly eliminated through the use of additives that scavenge peroxide or peroxyl radicals. (3) Characterization of GDL using dry gases is incorrect due to the fact that fuel cells operate utilizing humidified gases. The proper characterization method involves using wet gas streams and measuring capillary pressure as demonstrated in this project. (4) Not all Platinum on carbon catalysts are created equally – the major factor impacting catalyst durability is the type of carbon used as the support. (5) System operating conditions have a significant impact of lifetime – the lifetime was increased by an order of magnitude by changing the load profile while all other variables remain

  19. You make me tired: An experimental test of the role of interpersonal operant conditioning in fatigue.

    Science.gov (United States)

    Lenaert, Bert; Jansen, Rebecca; van Heugten, Caroline M

    2018-04-01

    Chronic fatigue is highly prevalent in the general population as well as in multiple chronic diseases and psychiatric disorders. Its etiology however remains poorly understood and cannot be explained by biological factors alone. Occurring in a psychosocial context, the experience and communication of fatigue may be shaped by social interactions. In particular, interpersonal operant conditioning may strengthen and perpetuate fatigue complaints. In this experiment, individuals (N = 44) repeatedly rated their currently experienced fatigue while engaging in cognitive effort (working memory task). Subtle social reward was given when fatigue increased relative to the previous rating; or disapproval when fatigue decreased. In the control condition, only neutral feedback was given. Although all participants became more fatigued during cognitive effort, interpersonal operant conditioning led to increased fatigue reporting relative to neutral feedback. This effect occurred independently of conscious awareness. Interestingly, the experimental condition also performed worse on the working memory task. Results suggest that fatigue complaints (and cognitive performance) may become controlled by their consequences such as social reward, and not exclusively by their antecedents such as effort. Results have implications for treatment development and suggest that interpersonal operant conditioning may contribute to fatigue becoming a chronic symptom. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. 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.

  1. 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...

  2. Cocaine self-administration in social dyads using custom-built operant conditioning chambers.

    Science.gov (United States)

    Lacy, Ryan T; Strickland, Justin C; Smith, Mark A

    2014-10-30

    Traditionally, the analysis of intravenous drug self-administration is limited to conditions in which subjects are tested in isolation. This limits the translational appeal of these studies because drug use in humans often occurs in the presence of others. We used custom-built operant conditioning chambers that allowed social dyads visual, olfactory, auditory, and limited tactile contact while concurrently self-administering cocaine. Male rats were trained to respond according to a fixed interval schedule of reinforcement (with a limited hold) in order to determine if patterns of cocaine (0.75mg/kg/infusion) self-administration became more similar over time in social pairs. Cocaine self-administration was tested across five days according to a 10-min fixed interval schedule (with a 5-min limited hold). Quarter-life values (time at which 25% of responses were emitted per interval) were analyzed using intraclass correlations. The total number of reinforcers obtained did not vary across the five days of testing; however, quarter-life values became progressively more similar between individuals within the social dyads. Standard operant conditioning chambers are unable to assess responding in multiple animals due to their small size, the need to prevent subjects from responding on the lever of their partner, and the need to prevent infusion lines from entangling. By using custom-built social operant conditioning chambers, we assessed the effects of social contact on cocaine self-administration. Social operant conditioning chambers can be used as a preclinical method to examine social influences on drug self-administration under conditions that approximate human substance use. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Efficiency of Polymer Electrolyte Membrane Fuel Cell Stack

    Directory of Open Access Journals (Sweden)

    Hans Bosma

    2011-08-01

    Full Text Available This paper applies a feedforward control of optimal oxygen excess ratio that maximize net power (improve efficiency of a NedStack P8.0-64 PEM fuel cell stack (FCS system. Net powers profile as a function of oxygen excess ratio for some points of operation are analyzed by using FCS model. The relationships between stack current and the corresponding control input voltage that gives an optimal oxygen excess ratio are used to design a feedforward control scheme. The results of this scheme are compared to the results of a feedforward control using a constant oxygen excess ratio. Simulation results show that optimal oxygen excess ratio improves fuel cell performance compared to the results of constant oxygen excess ratio. The same procedures are performed experimentally for the FCS system. The behaviour of the net power of the fuel cell stack with respect to the variation of oxygen excess ratio is analyzed to obtain optimal values. Data of stack current and the corresponding voltage input to the compressor that gives optimal values of oxygen excess ratio are used to develop a feedforward control. Feedforward control based on constant and optimal oxygen excess ratio control, are implemented in the NedStack P8.0-64 PEM fuel cell stack system by using LabVIEW. Implementation results shows that optimal oxygen excess ratio control improves the fuel cell performance compared to the constant oxygen excess ratio control.

  4. Comparative Analysis of Direct and Indirect 131I Measurement Methods from the Stack to Outdoor

    Directory of Open Access Journals (Sweden)

    G. Suhariyono

    2017-11-01

    Full Text Available The radioisotope production facility at PUSPIPTEK Serpong produces and processes 131I that can disperse to the settlements (community and the environment around the Serpong Nuclear Area (SNA. 131I is produced routinely for medical uses in hospitals and pharmacies, for both domestic uses and export. 131I is a beta and gamma emitting radioactive material and can cause thyroid cancer. The problem was that there was so far no research and in-depth assessment of the aerial dispersion of 131I radioactivity emitted from the radioisotope production stack to the environment at actual conditions. The research was conducted through simultaneous measurement of 131I radioactivity in the stack of the 131I radioisotope production facility, Serpong, and outdoor in house courtyards around SNA in normal condition (no accident based on the variations of the distance and wind direction. Direct measurements were carried out with a portable in-situ NaI(Tl detector at outdoor, and with a LaBr3 detector in the stack. Indirect measurements were carried out by using charcoal filter and vacuum pump in the stack and outdoor. The direct measurement method has many advantages over the indirect measurement. The direct measurement method was found to be more accurate, less expensive, easier to operate, needing just one operator in its implementation, portable, and can be operated continuously and for long durations. The overall activity concentrations of 131I on average obtained by either direct or indirect method were still below the upper limit of 131I activity concentration in the air (530 Bq/m3 stipulated by the Regulation of the Chairman of BAPETEN (Perka BAPETEN No. 7/2013. 

  5. A knowledge based operator support system for emergency conditions in nuclear power plants

    International Nuclear Information System (INIS)

    Venkatesh Babu, C.; Subramanium, K.

    1992-01-01

    The control centres of the operating Indian nuclear power plants contain a large number of indicators and controls spread over many panels. In the event of onset of an emergency condition, there results a profusion of information, both numeric and symbolic. The operator may succumb to an information and cognitive overload that may be compounded by a lack of knowledge. The failure to apply knowledge and reasoning to solve an operational problem can lead to human error, which has been a major contributing factor in nuclear accidents. From the viewpoint of Artificial Intelligence, human error occurs if the operational problem requires computing resources that exceed human capabilities. The application of Artificial Intelligence, particularly expert systems, to nuclear power plant control room activities has considerable potential to reduce operator error and improve safety and reliability. The purpose of this paper is to discuss an investigative study of the feasibility of developing an operator support system incorporating Artificial Intelligence techniques. An information processing model of such a system, herein designated as Knowledge Based Operator Support System - KBOSS, employing expert systems technology, has been developed. The features of this system are described, and issues involved in its development are discussed. (author). 2 refs., 5 figs., 1 tab

  6. Manufacturing of cells and stacks for SOFC development, test and demonstration projects and SOFC hotbox design development

    Energy Technology Data Exchange (ETDEWEB)

    2008-09-15

    The purpose of this project is to support the continued SOFC development through manufacturing process optimization and manufacturing of SOFC cells and stacks. These cells and stacks will serve as a necessary base for the development activities and for the establishment of a number of test and demonstration activities. The manufacture will also help provide operating experience and reduce manufacturing cost. Another main focus of the manufacturing is to assure technical improvements and reliability. It is imperative to the eventual success of the technology that test and demonstration is carried out in the pre-market conditions that will exist for the next years in the three market segments targeted by TOFC (Distributed generation, micro CHP and APU incl. marine APU). Finally, the project also includes development activities focusing on the stack-system interface (hotbox design development) and on dealing with transients and start up and shut down times, which is of particular importance for APU and micro CHP applications. Three topics are addressed:1) Cell manufacture, including production development, capacity lift and manuf. of cells for test and demonstration; 2) Stack manufacture and test, including a test facility, stack manuf. and test of stacks in a system at HCV; 3) Hotbox design development, including design, prototype construction and testing. The progress of this project is documented. Major achievements are successful manufacture of adequate amounts of cells and stacks according to the application. Furthermore significant over-performance in design, construction and test of a methanol based hotbox prototype as well as publication of this. (au)

  7. Development of on-site PAFC stacks

    Energy Technology Data Exchange (ETDEWEB)

    Hotta, K.; Matsumoto, Y. [Kansai Electric Power Co., Amagasaki (Japan); Horiuchi, H.; Ohtani, T. [Mitsubishi Electric Corp., Kobe (Japan)

    1996-12-31

    PAFC (Phosphoric Acid Fuel Cell) has been researched for commercial use and demonstration plants have been installed in various sites. However, PAFC don`t have a enough stability yet, so more research and development must be required in the future. Especially, cell stack needs a proper state of three phases (liquid, gas and solid) interface. It is very difficult technology to keep this condition for a long time. In the small size cell with the electrode area of 100 cm{sup 2}, gas flow and temperature distributions show uniformity. But in the large size cell with the electrode area of 4000 cm{sup 2}, the temperature distributions show non-uniformity. These distributions would cause to be shorten the cell life. Because these distributions make hot-spot and gas poverty in limited parts. So we inserted thermocouples in short-stack for measuring three-dimensional temperature distributions and observed effects of current density and gas utilization on temperature.

  8. 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.

  9. Design, fabrication and performance of a mixed-reactant membraneless micro direct methanol fuel cell stack

    Science.gov (United States)

    Abrego-Martínez, J. C.; Moreno-Zuria, A.; Cuevas-Muñiz, F. M.; Arriaga, L. G.; Sun, Shuhui; Mohamedi, Mohamed

    2017-12-01

    In the present work, we report the design, fabrication and evaluation of a membraneless mixed-reactant and air-breathing microfluidic direct methanol fuel cell (ML-μDMFC) stack operated in passive mode. The operation under mixed-reactant conditions was achieved by using a highly methanol-tolerant Ag/Pt/CP cathode with ultra-low Pt loading in alkaline medium. Prior to the fabrication of the stack, a flow simulation was made in order to study the behavior of the reactants stream in the microchannel through the 2 cells. Subsequently, the device was tested in passive mode using a mixture of 5 M MeOH +0.5 M KOH. The results showed that by connecting the 2 cells in series, it is possible to effectively double the voltage of a single ML-μDMFC, as well as increasing the absolute power by 75% with practically no cost increase. The stack was capable of operate continuously for more than 2 h with a single charge of 40 μL, producing an OCV of 0.89 V and a maximum power density of 3.33 mW mgPt-1. Additionally, the device exhibited good stability throughout a 10 h test.

  10. 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.

  11. 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)

  12. Ways to improve the environmental conditions of their buses in operation on passenger routes of cities

    Directory of Open Access Journals (Sweden)

    Melnychuk S.V.

    2017-04-01

    Full Text Available The results of studies on operational and environmental parameters buses used on bus routes Zhitomir city. It uses statistical methods for determining the intensity of traffic, passenger traffic and ecology in traffic. To assess the environmental chosen stop with the greatest intensity of traffic, which is the probability of accumulation of pollution transport emissions that exceed permissible limits. Calculation of environmental pollution emission route for vehicles made stops street «Str. Hundreds of Heaven» «CUM», «vul. Hlibna» on the main trunk street Kievska. Results obtained environmental field experiments compared with the data defined calculation methods, based on the proposed use appropriate operational vehicles. The conclusions that indicate the seriousness of the problem and the urgency to address it. The system of environmental safety and road safety in Zhitomir requires significant improvements due to the increased quantities bus vehicles plying city routes. Recommendations to improve the ecological condition of intersections can be developed through the optimization of traffic using buses with environmentally improved operating parameters. Keywords: environmental and operational parameters; ecological safety; environmental assessment; intensity of traffic; passenger traffic; environmental conditions; operation; bus choice; stop.

  13. Online condition monitoring to enable extended operation of nuclear power plants

    International Nuclear Information System (INIS)

    Meyer, Ryan Michael; Bond, Leonard John; Ramuhalli, Pradeep

    2012-01-01

    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 of 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. (author)

  14. 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.

  15. Assessment of neutron skyshine near unmodified Accumulator Debuncher storage rings under Mu2e operational conditions

    Energy Technology Data Exchange (ETDEWEB)

    Cossairt, J.Donald; /Fermilab

    2010-12-01

    Preliminary plans for providing the proton beam needed by the proposed Mu2e experiment at Fermilab will require the transport of 8 GeV protons to the Accumulator/Debuncher where they be processed into an intensity and time structure useful for the experiment. The intensities involved are far greater that those encountered with antiprotons of the same kinetic energy in the same beam enclosures under Tevatron Collider operational conditions, the operating parameters for which the physical facilities of the Antiproton Source were designed. This note explores some important ramifications of the proposed operation for radiation safety and demonstrates the need for extensive modifications of significant portions of the shielding of the Accumulator Debuncher storage rings; notably that underneath the AP Service Buildings AP10, AP30, and AP50. While existing shielding is adequate for the current operating mode of the Accumulator/Debuncher as part of the Antiproton Source used in the Tevatron Collider program, without significant modifications of the shielding configuration in the Accumulator/Debuncher region and/or beam loss control systems far more effective than seen in most applications at Fermilab, the proposed operational mode for Mu2e is not viable for the following reasons: 1. Due to skyshine alone, under normal operational conditions large areas of the Fermilab site would be exposed to unacceptable levels of radiation where most of the Laboratory workforce and some members of the general public who regularly visit Fermilab would receive measurable doses annually, contrary to workforce, public, and DOE expectations concerning the As Low as Reasonably Achievable (ALARA) principle. 2. Under normal operational conditions, a sizeable region of the Fermilab site would also require fencing due to skyshine. The size of the areas involved would likely invite public inquiry about the significant and visible enlargement of Fermilab's posted radiological areas. 3. There

  16. 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.

  17. A paradigm for operant conditioning in blow flies (Phormia terrae novae Robineau-Desvoidy, 1830).

    Science.gov (United States)

    Sokolowski, Michel B C; Disma, Gérald; 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 decreases. Control procedures revealed that rate of responding is not a simple overall result of feeding or of aging. The flies entered into the hole only if the response was required to obtain the food.

  18. User Driven Image Stacking for ODI Data and Beyond via a Highly Customizable Web Interface

    Science.gov (United States)

    Hayashi, S.; Gopu, A.; Young, M. D.; Kotulla, R.

    2015-09-01

    While some astronomical archives have begun serving standard calibrated data products, the process of producing stacked images remains a challenge left to the end-user. The benefits of astronomical image stacking are well established, and dither patterns are recommended for almost all observing targets. Some archives automatically produce stacks of limited scientific usefulness without any fine-grained user or operator configurability. In this paper, we present PPA Stack, a web based stacking framework within the ODI - Portal, Pipeline, and Archive system. PPA Stack offers a web user interface with built-in heuristics (based on pointing, filter, and other metadata information) to pre-sort images into a set of likely stacks while still allowing the user or operator complete control over the images and parameters for each of the stacks they wish to produce. The user interface, designed using AngularJS, provides multiple views of the input dataset and parameters, all of which are synchronized in real time. A backend consisting of a Python application optimized for ODI data, wrapped around the SWarp software, handles the execution of stacking workflow jobs on Indiana University's Big Red II supercomputer, and the subsequent ingestion of the combined images back into the PPA archive. PPA Stack is designed to enable seamless integration of other stacking applications in the future, so users can select the most appropriate option for their science.

  19. 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

  20. Fuel flow distribution in SOFC stacks revealed by impedance spectroscopy

    DEFF Research Database (Denmark)

    Mosbæk, Rasmus Rode; Hjelm, Johan; Barfod, Rasmus

    2014-01-01

    . An operating stack is subject to compositional gradients in the gaseous reactant streams, and temperature gradients across each cell and across the stack, which complicates detailed analysis. An experimental stack with low ohmic resistance from Topsoe Fuel Cell A/S was characterized using Electrochemical...... Impedance Spectroscopy (EIS). The stack measurement geometry was optimized for EIS by careful selection of the placement of current feeds and voltage probes in order to minimize measurement errors. It was demonstrated that with the improved placement of current feeds and voltage probes it is possible...... to separate the loss contributions in an ohmic and a polarization part and that the low frequency response is useful in detecting mass transfer limitations. This methodology can be used to detect possible minor changes in the supply of gas to the individual cells, which is important when going to high fuel...

  1. On thermoeconomics of energy systems at variable load conditions: Integrated optimization of plant design and operation

    International Nuclear Information System (INIS)

    Piacentino, A.; Cardona, F.

    2007-01-01

    Thermoeconomics has been assuming a growing role among the disciplines oriented to the analysis of energy systems, its different methodologies allowing solution of problems in the fields of cost accounting, plant design optimisation and diagnostic of malfunctions. However, the thermoeconomic methodologies as such are particularly appropriate to analyse large industrial systems at steady or quasi-steady operation, but they can be hardly applied to small to medium scale units operating in unsteady conditions to cover a variable energy demand. In this paper, the fundamentals of thermoeconomics for systems operated at variable load are discussed, examining the cost formation process and, separately, the cost fractions related to capital depreciation (which require additional distinctions with respect to plants in steady operation) and to exergy consumption. The relevant effects of the efficiency penalty due to off design operation on the exergetic cost of internal flows are also examined. An original algorithm is proposed for the integrated optimization of plant design and operation based on an analytical solution by the Lagrange multipliers method and on a multi-objective decision function, expressed either in terms of net cash flow or primary energy saving. The method is suitable for application in complex energy systems, such as 'facilities of components of a same product' connected to external networks for power or heat distribution. For demonstrative purposes, the proposed thermoeconomically aided optimization is performed for a grid connected trigeneration system to be installed in a large hotel

  2. On the Similarity of Sturm-Liouville Operators with Non-Hermitian Boundary Conditions to Self-Adjoint and Normal Operators

    Czech Academy of Sciences Publication Activity Database

    Krejčiřík, David; Siegl, Petr; Železný, Jakub

    2014-01-01

    Roč. 8, č. 1 (2014), s. 255-281 ISSN 1661-8254 R&D Projects: GA MŠk LC06002; GA MŠk LC527; GA ČR GAP203/11/0701 Grant - others:GA ČR(CZ) GD202/08/H072 Institutional support: RVO:61389005 Keywords : Sturm-Liouville operators * non-symmetric Robin boundary conditions * similarity to normal or self-adjoint operators * discrete spectral operator * complex symmetric operator * PT-symmetry * metric operator * C operator * Hilbert-Schmidt operators Subject RIV: BE - Theoretical Physics Impact factor: 0.545, year: 2014

  3. Investigation of degradation effects in polymer electrolyte fuel cells under automotive-related operating conditions

    Science.gov (United States)

    Enz, S.; Dao, T. A.; Messerschmidt, M.; Scholta, J.

    2015-01-01

    The influence of artificial starvation effects during automotive-related operating conditions is investigated within a polymer electrolyte fuel cell (PEFC) using non-dispersive infrared sensors and a current scan shunt. Driving cycles (DC) and single load change experiments are performed with specific fuel and oxidant starvation conditions. Within the DC experiments, a maximal CO2 amount of 4.67 μmol per cycle is detected in the cathode and 0.97 μmol per cycle in the anode exhaust without reaching fuel starvation conditions during the DC. Massive cell reversal conditions occur within the single load change experiments as a result of anodic fuel starvation. As soon as a fuel starvation appears, the emitted CO2 increases exponentially in the anode and cathode exhaust. A maximal CO2 amount of 143.8 μmol CO2 on the anode side and 5.8 μmol CO2 on the cathode side is detected in the exhaust gases. The critical cell reversal conditions only occur by using hydrogen reformate as anode reactant. The influence of the starvation effects on the PEFC performance is investigated via polarization curves, cyclic and linear sweep voltammetry as well as electrochemical impedance spectroscopy. The PEFC performance is reduced by 47% as a consequence of the dynamic operation.

  4. Exploiting the Free Landsat Archive for Operational Monitoring of Ecosystem Condition and Change Across the Chesapeake Bay Watershed

    Science.gov (United States)

    BrowndeColstoun, Eric

    2010-01-01

    For the first time, all imagery acquired by the Landsat series of satellites is being made available by the USGS to users at no cost. This represents a key opportunity to use Landsat in a truly operational monitoring framework: large regions of the U.S. such as the Chesapeake Bay Watershed can now be analyzed using "wall-to-wall" imagery at timescales from approximately 1 month to several years. With the future launch of the Landsat Data Continuity Mission (LDCM) and Decadal Survey missions such as the hyperspectral HyspIRI, it is imperative to develop robust processing systems to perform annual ecosystem assessments over large regions such as the Chesapeake Bay. We have been working at NASA's Goddard Space Flight Center (GSFC) to develop an integrative framework for inserting 30m, annual, Landsat based data and derived products into the existing decision support system for the Bay, with a particular focus on ecosystem condition and changes over the entire watershed. The basic goal is to use a 'stack' of Landsat imagery with 40% or less cloud cover to produce multi-date (2005-2009 period), cloud/shadow/gap-free composited surface reflectance products that will support the creation of watershed scale land cover/ use products and the monitoring of ecosystem change across the Bay. Our scientific focus extends beyond the conventional definition of land cover (i.e. a classification of vegetation type) as we propose to monitor both changes in surface type (e.g. forest to urban), vegetation structure (e.g. forest disturbance due to logging or insect damage), as well as winter crop cover. These processes represent a continuum from large, interannual changes in land cover type, to subtler, intra-annual changes associated with short-term disturbance. The free Landsat data are being processed to surface reflectance and composited using the existing Landsat Ecosystem Disturbance Adaptive Processing System here at NASA/ GSFC, and land cover products (type, tree cover

  5. Detection of structural damage using novelty detection algorithm under variational environmental and operational conditions

    Science.gov (United States)

    El Mountassir, M.; Yaacoubi, S.; Dahmene, F.

    2015-07-01

    Novelty detection is a widely used algorithm in different fields of study due to its capabilities to recognize any kind of abnormalities in a specific process in order to ensure better working in normal conditions. In the context of Structural Health Monitoring (SHM), this method is utilized as damage detection technique because the presence of defects can be considered as abnormal to the structure. Nevertheless, the performance of such a method could be jeopardized if the structure is operating in harsh environmental and operational conditions (EOCs). In this paper, novelty detection statistical technique is used to investigate the detection of damages under various EOCs. Experiments were conducted with different scenarios: damage sizes and shapes. EOCs effects were simulated by adding stochastic noise to the collected experimental data. Different levels of noise were studied to determine the accuracy and the performance of the proposed method.

  6. Detection of structural damage using novelty detection algorithm under variational environmental and operational conditions

    International Nuclear Information System (INIS)

    Mountassir, M El; Yaacoubi, S; Dahmene, F

    2015-01-01

    Novelty detection is a widely used algorithm in different fields of study due to its capabilities to recognize any kind of abnormalities in a specific process in order to ensure better working in normal conditions. In the context of Structural Health Monitoring (SHM), this method is utilized as damage detection technique because the presence of defects can be considered as abnormal to the structure. Nevertheless, the performance of such a method could be jeopardized if the structure is operating in harsh environmental and operational conditions (EOCs). In this paper, novelty detection statistical technique is used to investigate the detection of damages under various EOCs. Experiments were conducted with different scenarios: damage sizes and shapes. EOCs effects were simulated by adding stochastic noise to the collected experimental data. Different levels of noise were studied to determine the accuracy and the performance of the proposed method. (paper)

  7. 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...

  8. 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 ...

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

    International Nuclear Information System (INIS)

    Feng, Ju; Sheng, Wen Zhong

    2014-01-01

    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

  10. 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....

  11. 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...

  12. 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.

  13. Transformer operating conditions under introduction of PV and EVs in an eco-district

    OpenAIRE

    Dang , Xuan-Linh; Petit , Marc; Codani , Paul

    2015-01-01

    International audience; —An analysis of the operating conditions of a power transformer with the introduction of photovoltaic (PV) panels and Electric Vehicles (EV) in an eco-district is conducted. The study focuses on: (a) determining the optimal transformer sizing when there is neither PV nor EV; and (b) characterizing the overloading periods of the transformer induced by the penetration of PV sources and EVs in the district. We compare two EV integration strategies: they are either conside...

  14. Monitoring concept to detect engine oil condition degradations to support a reliable drive operation

    OpenAIRE

    Rigol, Sascha

    2012-01-01

    The theoretical part of this research work summarised all the known potential lubricant\\ud degradation effects during engine operation and in particular with regard to the use of\\ud the current generation of biofuels. A qualitative risk assessment was conducted which outlined biodiesel as potentially the most critical fuel. A ‘black box’ model was used to outline the challenge of oil condition monitoring based on summative sensor measurement methods. The theoretical considerations were suppor...

  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. Fuel consumption in an air blower for agricultural use under different operating conditions

    OpenAIRE

    Silva, Robson L. da

    2017-01-01

    ABSTRACT Evaluation of fuel consumption in internal combustion engines (ICE) of agricultural machinery and equipment is important in determining the performance under various operating conditions, especially when using biofuels. This study consisted of experimental evaluation of the gasoline (petrol)/ethanol consumption in a two-stroke 1-cylinder ICE, Otto cycle, functioning as an air blower for agriculture and related applications. A methodology for tests of non-automotive ICE, based on ABNT...

  17. Remote Sensing of In-Flight Icing Conditions: Operational, Meteorological, and Technological Considerations

    Science.gov (United States)

    Ryerson, Charles C.

    2000-01-01

    Remote-sensing systems that map aircraft icing conditions in the flight path from airports or aircraft would allow icing to be avoided and exited. Icing remote-sensing system development requires consideration of the operational environment, the meteorological environment, and the technology available. Operationally, pilots need unambiguous cockpit icing displays for risk management decision-making. Human factors, aircraft integration, integration of remotely sensed icing information into the weather system infrastructures, and avoid-and-exit issues need resolution. Cost, maintenance, power, weight, and space concern manufacturers, operators, and regulators. An icing remote-sensing system detects cloud and precipitation liquid water, drop size, and temperature. An algorithm is needed to convert these conditions into icing potential estimates for cockpit display. Specification development requires that magnitudes of cloud microphysical conditions and their spatial and temporal variability be understood at multiple scales. The core of an icing remote-sensing system is the technology that senses icing microphysical conditions. Radar and microwave radiometers penetrate clouds and can estimate liquid water and drop size. Retrieval development is needed; differential attenuation and neural network assessment of multiple-band radar returns are most promising to date. Airport-based radar or radiometers are the most viable near-term technologies. A radiometer that profiles cloud liquid water, and experimental techniques to use radiometers horizontally, are promising. The most critical operational research needs are to assess cockpit and aircraft system integration, develop avoid-and-exit protocols, assess human factors, and integrate remote-sensing information into weather and air traffic control infrastructures. Improved spatial characterization of cloud and precipitation liquid-water content, drop-size spectra, and temperature are needed, as well as an algorithm to

  18. System for adding sulfur to a fuel cell stack system for improved fuel cell stability

    Science.gov (United States)

    Mukerjee, Subhasish [Pittsford, NY; Haltiner, Jr., Karl J; Weissman, Jeffrey G [West Henrietta, NY

    2012-03-06

    A system for adding sulfur to a fuel cell stack, having a reformer adapted to reform a hydrocarbon fuel stream containing sulfur contaminants, thereby providing a reformate stream having sulfur; a sulfur trap fluidly coupled downstream of the reformer for removing sulfur from the reformate stream, thereby providing a desulfurized reformate stream; and a metering device in fluid communication with the reformate stream upstream of the sulfur trap and with the desulfurized reformate stream downstream of the sulfur trap. The metering device is adapted to bypass a portion of the reformate stream to mix with the desulfurized reformate stream, thereby producing a conditioned reformate stream having a predetermined sulfur concentration that gives an acceptable balance of minimal drop in initial power with the desired maximum stability of operation over prolonged periods for the fuel cell stack.

  19. Safer operating conditions and optimal scaling-up process for cyclohexanone peroxide reaction

    International Nuclear Information System (INIS)

    Zang, Na; Qian, Xin-Ming; Liu, Zhen-Yi; Shu, Chi-Min

    2015-01-01

    Highlights: • Thermal hazard of cyclohexanone peroxide reaction was measured by experimental techniques. • Levenberg–Marquardt algorithm was adopted to evaluate kinetic parameters. • Safer operating conditions at laboratory scale were acquired by BDs and TDs. • The verified safer operating conditions were used to obtain the optimal scale-up parameters applied in industrial plants. - Abstract: The cyclohexanone peroxide reaction process, one of the eighteen hazardous chemical processes identified in China, is performed in indirectly cooled semibatch reactors. The peroxide reaction is added to a mixture of hydrogen peroxide and nitric acid, which form heterogeneous liquid–liquid systems. A simple and general procedure for building boundary and temperature diagrams of peroxide process is given here to account for the overall kinetic expressions. Such a procedure has been validated by comparison with experimental data. Thermally safer operating parameters were obtained at laboratory scale, and the scaled-up procedure was performed to give the minimum dosing time in an industrial plant, which is in favor of maximizing industrial reactor productivity. The results are of great significance for governing the peroxide reaction process apart from the thermal runaway region. It also greatly aids in determining optimization on operating parameters in industrial plants.

  20. 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.

  1. A Mathematical Model and Its Application for Hydro Power Units under Different Operating Conditions

    Directory of Open Access Journals (Sweden)

    Weijia Yang

    2015-09-01

    Full Text Available This paper presents a mathematical model of hydro power units, especially the governor system model for different operating conditions, based on the basic version of the software TOPSYS. The mathematical model consists of eight turbine equations, one generator equation, and one governor equation, which are solved for ten unknown variables. The generator and governor equations, which are different under various operating conditions, are presented and discussed in detail. All the essential non-linear factors in the governor system (dead-zone, saturation, rate limiting, and backlash are also considered. Case studies are conducted based on one Swedish hydro power plant (HPP and three Chinese plants. The simulation and on-site measurements are compared for start-up, no-load operation, normal operation, and load rejection in different control modes (frequency, opening, and power feedback. The main error in each simulation is also discussed in detail. As a result, the model application is proved trustworthy for simulating different physical quantities of the unit (e.g., guide vane opening, active power, rotation speed, and pressures at volute and draft tube. The model has already been applied effectively in consultant analyses and scientific studies.

  2. 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 %.

  3. 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.

  4. Numerical modelling of multi-vane expander operating conditions in ORC system

    Science.gov (United States)

    Rak, Józef; Błasiak, Przemysław; Kolasiński, Piotr

    2017-11-01

    Multi-vane expanders are positive displacement volumetric machines which are nowadays considered for application in micro-power domestic ORC systems as promising alternative to micro turbines and other volumetric expanders. The multi-vane expander features very simple design, low gas flow capacity, low expansion ratios, an advantageous ratio of the power output to the external dimensions and are insensitive to the negative influence of the gas-liquid mixture expansion. Moreover, the multi-vane expander can be easily hermetically sealed, which is one of the key issues in the ORC system design. A literature review indicates that issues concerning the application of multi-vane expanders in such systems, especially related to operating of multi-vane expander with different low-boiling working fluids, are innovative, not fully scientifically described and have the potential for practical implementation. In this paper the results of numerical investigations on multi-vane expander operating conditions are presented. The analyses were performed on three-dimensional numerical model of the expander in ANSYS CFX software. The numerical model of the expander was validated using the data obtained from the experiment carried out on a lab test-stand. Then a series of computational analysis were performed using expanders' numerical model in order to determine its operating conditions under various flow conditions of different working fluids.

  5. Numerical modelling of multi-vane expander operating conditions in ORC system

    Directory of Open Access Journals (Sweden)

    Rak Józef

    2017-01-01

    Full Text Available Multi-vane expanders are positive displacement volumetric machines which are nowadays considered for application in micro-power domestic ORC systems as promising alternative to micro turbines and other volumetric expanders. The multi-vane expander features very simple design, low gas flow capacity, low expansion ratios, an advantageous ratio of the power output to the external dimensions and are insensitive to the negative influence of the gas-liquid mixture expansion. Moreover, the multi-vane expander can be easily hermetically sealed, which is one of the key issues in the ORC system design. A literature review indicates that issues concerning the application of multi-vane expanders in such systems, especially related to operating of multi-vane expander with different low-boiling working fluids, are innovative, not fully scientifically described and have the potential for practical implementation. In this paper the results of numerical investigations on multi-vane expander operating conditions are presented. The analyses were performed on three-dimensional numerical model of the expander in ANSYS CFX software. The numerical model of the expander was validated using the data obtained from the experiment carried out on a lab test-stand. Then a series of computational analysis were performed using expanders' numerical model in order to determine its operating conditions under various flow conditions of different working fluids.

  6. Directly connected series coupled HTPEM fuel cell stacks to a Li-ion battery DC bus for a fuel cell electrical vehicle

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Ashworth, Leanne; Remón, Ian Natanael

    2008-01-01

    The work presented in this paper examines the use of pure hydrogen fuelled high temperature polymer electrolyte membrane (HTPEM) fuel cell stacks in an electrical car, charging a Li-ion battery pack. The car is equipped with two branches of two series coupled 1 kW fuel cell stacks which...... are connected directly parallel to the battery pack during operation. This enables efficient charging of the batteries for increased driving range. With no power electronics used, the fuel cell stacks follow the battery pack voltage, and charge the batteries passively. This saves the electrical and economical...... losses related to these components and their added system complexity. The new car battery pack consists of 23 Li-ion battery cells and the charging and discharging are monitored by a battery management system (BMS) which ensures safe operating conditions for the batteries. The direct connection...

  7. A novel attention training paradigm based on operant conditioning of eye gaze: Preliminary findings.

    Science.gov (United States)

    Price, Rebecca B; Greven, Inez M; Siegle, Greg J; Koster, Ernst H W; De Raedt, Rudi

    2016-02-01

    Inability to engage with positive stimuli is a widespread problem associated with negative mood states across many conditions, from low self-esteem to anhedonic depression. Though attention retraining procedures have shown promise as interventions in some clinical populations, novel procedures may be necessary to reliably attenuate chronic negative mood in refractory clinical populations (e.g., clinical depression) through, for example, more active, adaptive learning processes. In addition, a focus on individual difference variables predicting intervention outcome may improve the ability to provide such targeted interventions efficiently. To provide preliminary proof-of-principle, we tested a novel paradigm using operant conditioning to train eye gaze patterns toward happy faces. Thirty-two healthy undergraduates were randomized to receive operant conditioning of eye gaze toward happy faces (train-happy) or neutral faces (train-neutral). At the group level, the train-happy condition attenuated sad mood increases following a stressful task, in comparison to train-neutral. In individual differences analysis, greater physiological reactivity (pupil dilation) in response to happy faces (during an emotional face-search task at baseline) predicted decreased mood reactivity after stress. These Preliminary results suggest that operant conditioning of eye gaze toward happy faces buffers against stress-induced effects on mood, particularly in individuals who show sufficient baseline neural engagement with happy faces. Eye gaze patterns to emotional face arrays may have a causal relationship with mood reactivity. Personalized medicine research in depression may benefit from novel cognitive training paradigms that shape eye gaze patterns through feedback. Baseline neural function (pupil dilation) may be a key mechanism, aiding in iterative refinement of this approach. (c) 2016 APA, all rights reserved).

  8. 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 contain...

  9. Solid oxide fuel cell short stack performance testing - Part A: Experimental analysis and μ-combined heat and power unit comparison

    Science.gov (United States)

    Mastropasqua, L.; Campanari, S.; Brouwer, J.

    2017-12-01

    The need to experimentally understand the detailed performance of SOFC stacks under operating conditions typical of commercial SOFC systems has prompted this two-part study. The steady state performance of a 6-cell short stack of yttria (Y2O3) stabilised zirconia (YSZ) with Ni/YSZ anodes and composite Sr-doped lanthanum manganite (LaMnO3, LSM)/YSZ cathodes is experimentally evaluated. In Part A, the stack characterisation is carried out by means of sensitivity analyses on the fuel utilisation factor and the steam-to-carbon ratio. Electrical and environmental performances are assessed and the results are compared with a commercial full-scale micro-CHP system, which comprises the same cells. The results show that the measured temperature dynamics of the short stack in a test stand environment are on the order of many minutes; therefore, one cannot neglect temperature dynamics for a precise measurement of the steady state polarisation behaviour. The overall polarisation performance is comparable to that of the full stack employed in the micro-CHP system, confirming the good representation that short-stack analyses can give of the entire SOFC module. The environmental performance is measured verifying the negligible values of NO emissions (<10 ppb) across the whole polarisation curve.

  10. planSOEC. R and D and commercialization roadmap for SOEC electrolysis. R and D of SOEC stacks with improved durability. Project report

    Energy Technology Data Exchange (ETDEWEB)

    Richter, A.; Friis Pedersen, C.; Nielsen, Jens Ulrik [Topsoe Fuel Cells A/S, Kgs. Lyngby (Denmark); Mogensen, M.; Hoejgaard Jensen, S.; Ming Chen [Technical Univ. of Denmark. Fuel Cells and Solid State Chemistry Div., DTU Risoe Campus, Roskilde (Denmark); Sloth, M. [H2 Logic A/S, Herning (Denmark)

    2011-05-15

    The project has been divided into two parts: PART 1: Formulation of a R and D and commercialization roadmap for SOEC electrolysis. PART 2: Conducting R and D of SOEC stacks with improved durability. The purpose of Part 1 has been to develop a R and D and commercialisation roadmap for hydrogen and CO production plants based on the solid oxide electrolysis cell (SOEC) technology. SOEC technology is still on an early R and D stage but years of extensive R and D within SOFC technology provides a strong platform for an accelerated commercialisation. However, in order to guide the future SOEC R and D activities towards reaching commercial market requirements a detailed roadmap is necessary. An overall strategy for R and D of various electrolysis technologies in Denmark already exists{sup 2}, formulated in the Hydrogen Production working group in the Danish Hydrogen and Fuel Cell Partnership. The SOEC roadmap developed as part of the planSOEC project supplements the overall strategy, by conducting an updated analysis of state-of-the-art. Also planSOEC provides a detailed analysis of requirements for different market applications for SOEC, which enables formulation of precise and detailed R and D targets. The objectives of Part 2 in this project were multiple: 1) To investigate durability of solid oxide cells (SOCs) and stack components under industrially relevant (''harsh'') electrolysis operating conditions; 2) to investigate performance of standard TOFC (Topsoe Fuel Cell A/S) SOC stacks (based on state-of-the-art solid oxide cells) under mild electrolysis operating conditions ({<=}0.75 A/cm{sup 2}); 3) to further develop SOEC stack computer models available at Riso DTU and TOFC. Accordingly four lines of work were carried out in the here reported project: 1) Investigation of corrosion resistance of interconnect alloys. 2) Cell and stack element testing. 3) SOEC stack testing. 4) SOEC stack modeling. (LN)

  11. Restoring walking after spinal cord injury: operant conditioning of spinal reflexes can help.

    Science.gov (United States)

    Thompson, Aiko K; Wolpaw, Jonathan R

    2015-04-01

    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 electromyographic 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. © The Author(s) 2014.

  12. Design Criteria, Operating Conditions, and Nickel-Iron Hydroxide Catalyst Materials for Selective Seawater Electrolysis.

    Science.gov (United States)

    Dionigi, Fabio; Reier, Tobias; Pawolek, Zarina; Gliech, Manuel; Strasser, Peter

    2016-05-10

    Seawater is an abundant water resource on our planet and its direct electrolysis has the advantage that it would not compete with activities demanding fresh water. Oxygen selectivity is challenging when performing seawater electrolysis owing to competing chloride oxidation reactions. In this work we propose a design criterion based on thermodynamic and kinetic considerations that identifies alkaline conditions as preferable to obtain high selectivity for the oxygen evolution reaction. The criterion states that catalysts sustaining the desired operating current with an overpotential seawater-mimicking electrolyte. The catalyst was synthesized by a solvothermal method and the activity, surface redox chemistry, and stability were tested electrochemically in alkaline and near-neutral conditions (borate buffer at pH 9.2) and under both fresh seawater conditions. The Tafel slope at low current densities is not influenced by pH or presence of chloride. On the other hand, the addition of chloride ions has an influence in the temporal evolution of the nickel reduction peak and on both the activity and stability at high current densities at pH 9.2. Faradaic efficiency close to 100 % under the operating conditions predicted by our design criteria was proven using in situ electrochemical mass spectrometry. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Performance analysis of air conditioning system and airflow simulation in an operating theater

    Science.gov (United States)

    Alhamid, Muhammad Idrus; Budihardjo, Rahmat

    2018-02-01

    The importance of maintaining performance of a hospital operating theater is to establish an adequate circulation of clean air within the room. The parameter of air distribution in a space should be based on Air Changes per Hour (ACH) to maintain a positive room pressure. The dispersion of airborne particles in the operating theater was governed by regulating the air distribution so that the operating theater meets clean room standards ie ISO 14664 and ASHRAE 170. Here, we introduced several input parameters in a simulation environment to observe the pressure distribution in the room. Input parameters were air temperature, air velocity and volumetric flow rate entering and leaving room for existing and designed condition. In the existing operating theatre, several observations were found. It was found that the outlet air velocity at the HEPA filter above the operating table was too high thus causing a turbulent airflow pattern. Moreover, the setting temperature at 19°C was found to be too low. The supply of air into the room was observed at lower than 20 ACH which is under the standard requirement. Our simulation using FloVent 8.2™ program showed that not only airflow turbulence could be reduced but also the amount of particle contamination could also be minimized.

  14. Operant conditioning of neural activity in freely behaving monkeys with intracranial reinforcement.

    Science.gov (United States)

    Eaton, Ryan W; Libey, Tyler; Fetz, Eberhard E

    2017-03-01

    Operant conditioning of neural activity has typically been performed under controlled behavioral conditions using food reinforcement. This has limited the duration and behavioral context for neural conditioning. To reward cell activity in unconstrained primates, we sought sites in nucleus accumbens (NAc) whose stimulation reinforced operant responding. In three monkeys, NAc stimulation sustained performance of a manual target-tracking task, with response rates that increased monotonically with increasing NAc stimulation. We recorded activity of single motor cortex neurons and documented their modulation with wrist force. We conditioned increased firing rates with the monkey seated in the training booth and during free behavior in the cage using an autonomous head-fixed recording and stimulating system. Spikes occurring above baseline rates triggered single or multiple electrical pulses to the reinforcement site. Such rate-contingent, unit-triggered stimulation was made available for periods of 1-3 min separated by 3-10 min time-out periods. Feedback was presented as event-triggered clicks both in-cage and in-booth, and visual cues were provided in many in-booth sessions. In-booth conditioning produced increases in single neuron firing probability with intracranial reinforcement in 48 of 58 cells. Reinforced cell activity could rise more than five times that of non-reinforced activity. In-cage conditioning produced significant increases in 21 of 33 sessions. In-cage rate changes peaked later and lasted longer than in-booth changes, but were often comparatively smaller, between 13 and 18% above non-reinforced activity. Thus intracranial stimulation reinforced volitional increases in cortical firing rates during both free behavior and a controlled environment, although changes in the latter were more robust. NEW & NOTEWORTHY Closed-loop brain-computer interfaces (BCI) were used to operantly condition increases in muscle and neural activity in monkeys by delivering

  15. Condition monitoring of a motor-operated valve using estimated motor torque

    International Nuclear Information System (INIS)

    Chai, Jangbom; Kang, Shinchul; Park, Sungkeun; Hong, Sungyull; Lim, Chanwoo

    2004-01-01

    This paper is concerned with the development of data analysis methods to be used in on-line monitoring and diagnosis of Motor-Operated Valves (MOVs) effectively and accurately. The technique to be utilized includes the electrical measurements and signal processing to estimate electric torque of induction motors, which are attached to most of MOV systems. The estimated torque of an induction motor is compared with the directly measured torque using a torque cell in various loading conditions including the degraded voltage conditions to validate the estimating scheme. The accuracy of the estimating scheme is presented. The advantages of the estimated torque signatures are reviewed over the currently used ones such as the current signature and the power signature in several respects: accuracy, sensitivity, resolution and so on. Additionally, the estimated torque methods are suggested as a good way to monitor the conditions of MOVs with higher accuracy. (author)

  16. The refined analytic torsion and a well-posed boundary condition for the odd signature operator

    Science.gov (United States)

    Huang, Rung-Tzung; Lee, Yoonweon

    2018-03-01

    In this paper we discuss the refined analytic torsion on an odd dimensional compact oriented Riemannian manifold with boundary under some assumption. For this purpose we introduce two boundary conditions which are complementary to each other and well-posed for the odd signature operator B in the sense of Seeley. We then show that the zeta-determinants of B2 and eta-invariants of B subject to these boundary conditions are well defined by using the method of the asymptotic expansions of the traces of the heat kernels. We use these facts to define the refined analytic torsion on a compact manifold with boundary and show that it is invariant on the change of metrics in the interior of the manifold. We finally describe the refined analytic torsion under these boundary conditions as an element of the determinant line.

  17. Visual perceptual learning by operant conditioning training follows rules of contingency.

    Science.gov (United States)

    Kim, Dongho; Seitz, Aaron R; Watanabe, Takeo

    2015-01-01

    Visual perceptual learning (VPL) can occur as a result of a repetitive stimulus-reward pairing in the absence of any task. This suggests that rules that guide Conditioning, such as stimulus-reward contingency (e.g. that stimulus predicts the likelihood of reward), may also guide the formation of VPL. To address this question, we trained subjects with an operant conditioning task in which there were contingencies between the response to one of three orientations and the presence of reward. Results showed that VPL only occurred for positive contingencies, but not for neutral or negative contingencies. These results suggest that the formation of VPL is influenced by similar rules that guide the process of Conditioning.

  18. Operant conditioning of enhanced pain sensitivity by heat-pain titration.

    Science.gov (United States)

    Becker, Susanne; Kleinböhl, Dieter; Klossika, Iris; Hölzl, Rupert

    2008-11-15

    Operant conditioning mechanisms have been demonstrated to be important in the development of chronic pain. Most experimental studies have investigated the operant modulation of verbal pain reports with extrinsic reinforcement, such as verbal reinforcement. Whether this reflects actual changes in the subjective experience of the nociceptive stimulus remained unclear. This study replicates and extends our previous demonstration that enhanced pain sensitivity to prolonged heat-pain stimulation could be learned in healthy participants through intrinsic reinforcement (contingent changes in nociceptive input) independent of verbal pain reports. In addition, we examine whether different magnitudes of reinforcement differentially enhance pain sensitivity using an operant heat-pain titration paradigm. It is based on the previously developed non-verbal behavioral discrimination task for the assessment of sensitization, which uses discriminative down- or up-regulation of stimulus temperatures in response to changes in subjective intensity. In operant heat-pain titration, this discriminative behavior and not verbal pain report was contingently reinforced or punished by acute decreases or increases in heat-pain intensity. The magnitude of reinforcement was varied between three groups: low (N1=13), medium (N2=11) and high reinforcement (N3=12). Continuous reinforcement was applied to acquire and train the operant behavior, followed by partial reinforcement to analyze the underlying learning mechanisms. Results demonstrated that sensitization to prolonged heat-pain stimulation was enhanced by operant learning within 1h. The extent of sensitization was directly dependent on the received magnitude of reinforcement. Thus, operant learning mechanisms based on intrinsic reinforcement may provide an explanation for the gradual development of sustained hypersensitivity during pain that is becoming chronic.

  19. Exact and heuristic solutions to the Double TSP with Multiple Stacks

    DEFF Research Database (Denmark)

    Petersen, Hanne Løhmann; Archetti, Claudia; Madsen, Oli B.G.

    The double travelling salesman problem with multiple stacks (DTSPMS) is a pickup and delivery problem where pickups and deliveries are separated, such that all pickup operations are performed before the first delivery takes place. All operations are carried out by one vehicle and no reloading...... is allowed. The vehicle provides several separated (horizontal) stacks/rows for the transportation of the orders, such that each stack is accessed using a LIFO principle, independently of the other stacks. In a real-life setting the dimensions of the problem is 33 orders each consisting of one euro...

  20. Compliant Glass Seals for SOFC Stacks

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Yeong -Shyung [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Choi, Jung-Pyung [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Xu, Wei [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Stephens, Elizabeth V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Koeppel, Brian J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Stevenson, Jeffry W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lara-Curzio, Edgar [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-04-30

    This report summarizes results from experimental and modeling studies performed by participants in the Solid-State Energy Conversion Alliance (SECA) Core Technology Program, which indicate that compliant glass-based seals offer a number of potential advantages over conventional seals based on de-vitrifying glasses, including reduced stresses during stack operation and thermal cycling, and the ability to heal micro-damage induced during thermal cycling. The properties and composition of glasses developed and/or investigated in these studies are reported, along with results from long-term (up to 5,800h) evaluations of seals based on a compliant glass containing ceramic particles or ceramic fibers.

  1. The stack calculus

    Directory of Open Access Journals (Sweden)

    Alberto Carraro

    2013-03-01

    Full Text Available We introduce a functional calculus with simple syntax and operational semantics in which the calculi introduced so far in the Curry-Howard correspondence for Classical Logic can be faithfully encoded. Our calculus enjoys confluence without any restriction. Its type system enforces strong normalization of expressions and it is a sound and complete system for full implicational Classical Logic. We give a very simple denotational semantics which allows easy calculations of the interpretation of expressions.

  2. 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.

  3. Time-predictable Stack Caching

    DEFF Research Database (Denmark)

    Abbaspourseyedi, Sahar

    completely. Thus, in systems with hard deadlines the worst-case execution time (WCET) of the real-time software running on them needs to be bounded. Modern architectures use features such as pipelining and caches for improving the average performance. These features, however, make the WCET analysis more...... addresses, provides an opportunity to predict and tighten the WCET of accesses to data in caches. In this thesis, we introduce the time-predictable stack cache design and implementation within a time-predictable processor. We introduce several optimizations to our design for tightening the WCET while...... keeping the timepredictability of the design intact. Moreover, we provide a solution for reducing the cost of context switching in a system using the stack cache. In design of these caches, we use custom hardware and compiler support for delivering time-predictable stack data accesses. Furthermore...

  4. Glassy carbon based supercapacitor stacks

    Energy Technology Data Exchange (ETDEWEB)

    Baertsch, M.; Braun, A.; Koetz, R.; Haas, O. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    Considerable effort is being made to develop electrochemical double layer capacitors (EDLC) that store relatively large quantities of electrical energy and possess at the same time a high power density. Our previous work has shown that glassy carbon is suitable as a material for capacitor electrodes concerning low resistance and high capacity requirements. We present the development of bipolar electrochemical glassy carbon capacitor stacks of up to 3 V. Bipolar stacks are an efficient way to meet the high voltage and high power density requirements for traction applications. Impedance and cyclic voltammogram measurements are reported here and show the frequency response of a 1, 2, and 3 V stack. (author) 3 figs., 1 ref..

  5. Nuclear fuel rod with retainer for pellet stack

    International Nuclear Information System (INIS)

    Cloue, J.M.

    1986-01-01

    The rod, usable in pressurized water reactors, comprises a stack of fuel pellets and means holding the stack against an end plug of the fuel can during handling operations. These means include a radially expansive element (retainer) of which the shape is so that when it is free at ambient temperature it is gripping the inside of the casing, and a temperature sensitive spacer which contracts the retainer to release it from the casing at a temperature between the ambient and the operating temperature of a reactor [fr

  6. Single-photon detector operating under extremely high background photon flux conditions

    International Nuclear Information System (INIS)

    Prochazka, Ivan; Sopko, Bruno; Blazej, Josef

    2009-01-01

    We are reporting our results in research and development in the field of avalanche semiconductor single-photon detectors and their application. Our goal was a development of a solid-state photon-counting detector capable of high-precision photon arrival time tagging in extremely harsh operating conditions. The background photon flux exceeding 10 9 photons per second hitting the detector active area should not avoid the useful signal detection and recognition on the signal level of units of photons per second. This is background photon flux about two orders of magnitude higher than what the conventional solid-state photon counters accept. The detection timing resolution should be better than 100 ps and the delay stability should be on picosecond level. We have developed and tested the active quenched and gated avalanche structure on silicon providing the required features in connection with the K14 detection chips. The detector is capable of gated operation under the conditions of background photon flux of 5x10 9 photons per second. The operational detector tolerates long term exposures to the input photon flux exceeding 10 15 photons (>1 mW) per second without damage.

  7. 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.

  8. Experimental investigations on a common centrifugal pump operating under gas entrainment conditions

    International Nuclear Information System (INIS)

    Schäfer, Thomas; Neumann, Martin; Bieberle, André; Hampel, Uwe

    2017-01-01

    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.

  9. Application-ready expedited MODIS data for operational land surface monitoring of vegetation condition

    Science.gov (United States)

    Brown, Jesslyn; Howard, Daniel M.; Wylie, Bruce K.; Friesz, Aaron M.; Ji, Lei; Gacke, Carolyn

    2015-01-01

    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.

  10. 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.

  11. Analysis of winter weather conditions and their potential impact on wind farm operations

    Science.gov (United States)

    Novakovskaia, E.; Treinish, L. A.; Praino, A.

    2009-12-01

    Severe weather conditions have two primary impacts on wind farm operations. The first relates to understanding potential damage to the turbines themselves and what actions are required to mitigate the effects. The second is recognizing what conditions may lead to a full or partial shutdown of the wind farm with sufficient lead time to determine the likely inability to meet energy generation committments. Ideally, wind forecasting suitable for wind farm operations should be of sufficient fidelity to resolve features within the boundary layer that lead to either damaging conditions or useful power generation. Given the complexity of the site-specific factors that effect the boundary layer at the scale of typical land-based wind farm locations such as topography, vegetation, land use, soil conditions, etc., which may vary with turbine design and layout within the farm, enabling reliable forecasts of too little or too much wind is challenging. A potential solution should involve continuous updates of alert triggering criteria through analysis of local wind patterns and probabilistic risk assessment for each location. To evaluate this idea, we utilize our operational mesoscale prediction system, dubbed “Deep Thunder”, developed at the IBM Thomas J. Watson Research Center. In particular, we analyze winter-time near-surface winds in upstate New York, where four similar winds farms are located. Each of these farms were built at roughly the same time and utilize similar turbines. Given the relative uncertainty associated with numerical weather prediction at this scale, and the difference in risk assessment due to the two primary impacts of severe weather, probabilistic forecasts are a prerequisite. Hence, we have employed ensembles of weather scenarios, which are based on the NCAR WRF-ARW modelling system. The set of ensemble members was composed with variations in the choices of physics and parameterization schemes, and source of background fields for initial

  12. Fan Efficiency Improvement via Changing Guide Blade Shape Under Various Operating Conditions

    Directory of Open Access Journals (Sweden)

    G. I. Zamolodchikov

    2017-01-01

    Full Text Available The aim of this study is to examine the influence of sweep and tangential blade lean the guide vanes (GV on the pressure losses in the blade row, and development of an approach to creating the GV with a rationally-shaped blades to ensure increased efficiency in the partial operating conditions.A numerical simulation method was used for research. As an object to be studied, was used an axial fan comprising an impeller and a GV, which were profiled to have constant circulation of velocity in radius. Verification of numerical simulation was based on the experimental data of fan. It comprised a GV with a straight blade and a circular-arc blade, with an impeller remained stationary in both cases. Among the turbulence models under consideration, preference is given to k-ω, as under operating conditions close to design ones, its result falls within the confidence span of the experimental characteristics, and at much higher and lower discharge coefficients a discrepancy is 4% at most.  In addition to the characteristics, the fields of pressure losses in GV have been analyzed. Numerical modeling allowed us to have a well-reproduced structure of losses in the stationary blade row.Analysis of pressure loss fields has shown that in the original GV near the hub, on the blade back, under design conditions a flow breakdown takes off. In view of the research, was designed a new GV with a modified blade geometry. The GV blade axis near the hub was bent in the circumferential direction by 0.1 length of the blade. In the near-hub cross-sections the blade chord was increased by 10%.The results of numerical simulation have shown that, with the flow less than the designed one, a change of just the GV blade tip sections leads to reduced break-down zone near the hub by about 40% under both operating conditions without raising profile losses and to improved fan efficiency, which reduces fan drive power consumption under typical operating conditions in the propulsion

  13. Controlling for peak power extraction from microbial fuel cells can increase stack voltage and avoid cell reversal

    Science.gov (United States)

    Boghani, Hitesh C.; Papaharalabos, George; Michie, Iain; Fradler, Katrin R.; Dinsdale, Richard M.; Guwy, Alan J.; Ieropoulos, Ioannis; Greenman, John; Premier, Giuliano C.

    2014-12-01

    Microbial fuel cells (MFCs) are bioelectrochemical systems which can degrade organic materials and are increasingly seen as potential contributors to low carbon technologies, particularly in energy recovery from and treatment of wastewaters. The theoretical maximum open circuit voltage from MFCs lies in the region of 1.1 V, but is reduced substantially by overvoltage losses. Practical use of the power requires stacking or other means to increase voltage. Series stacking of MFCs with typically encountered variability in operating conditions and performance raises the risk of cell reversal, which diminishes overall power performance. A novel strategy of MFC subsystem series connectivity along with maximum power point tracking (MPPT) generates increased power from individual MFCs whilst eliminating cell reversal. MFCs fed with lower concentrations of substrate experienced voltage reversal when connected in normal series connection with one common load, but when MFCs and loads together were connected in series, the underperforming cell is effectively bypassed and maximum power is made available. It is concluded that stack voltage may be increased and cell reversal avoided using the hybrid connectivity along with MPPT. This approach may be suitable for stacked MFC operations in the event that large scale arrays/modules are deployed in treating real wastewaters.

  14. The Relationship between Human Operators' Psycho-physiological Condition and Human Errors in Nuclear Power Plants

    International Nuclear Information System (INIS)

    Kim, Arryum; Jang, Inseok; Kang, Hyungook; Seong, Poonghyun

    2013-01-01

    The safe operation of nuclear power plants (NPPs) is substantially dependent on the performance of the human operators who operate the systems. In this environment, human errors caused by inappropriate performance of operator have been considered to be critical since it may lead serious problems in the safety-critical plants. In order to provide meaningful insights to prevent human errors and enhance the human performance, operators' physiological conditions such as stress and workload have been investigated. Physiological measurements were considered as reliable tools to assess the stress and workload. T. Q. Tran et al. and J. B. Brooking et al pointed out that operators' workload can be assessed using eye tracking, galvanic skin response, electroencephalograms (EEGs), heart rate, respiration and other measurements. The purpose of this study is to investigate the effect of the human operators' tense level and knowledge level to the number of human errors. For this study, the experiments were conducted in the mimic of the main control rooms (MCR) in NPP. It utilized the compact nuclear simulator (CNS) which is modeled based on the three loop Pressurized Water Reactor, 993MWe, Kori unit 3 and 4 in Korea and the subjects were asked to follow the tasks described in the emergency operating procedures (EOP). During the simulation, three kinds of physiological measurement were utilized; Electrocardiogram (ECG), EEG and nose temperature. Also, subjects were divided into three groups based on their knowledge of the plant operation. The result shows that subjects who are tense make fewer errors. In addition, subjects who are in higher knowledge level tend to be tense and make fewer errors. For the ECG data, subjects who make fewer human errors tend to be located in higher tense level area of high SNS activity and low PSNS activity. The results of EEG data are also similar to ECG result. Beta power ratio of subjects who make fewer errors was higher. Since beta power ratio is

  15. Multiple Segmentation of Image Stacks

    DEFF Research Database (Denmark)

    Smets, Jonathan; Jaeger, Manfred

    2014-01-01

    We propose a method for the simultaneous construction of multiple image segmentations by combining a recently proposed “convolution of mixtures of Gaussians” model with a multi-layer hidden Markov random field structure. The resulting method constructs for a single image several, alternative...... segmentations that capture different structural elements of the image. We also apply the method to collections of images with identical pixel dimensions, which we call image stacks. Here it turns out that the method is able to both identify groups of similar images in the stack, and to provide segmentations...

  16. Simulating Small-Scale Object Stacking Using Stack Stability

    DEFF Research Database (Denmark)

    Kronborg Thomsen, Kasper; Kraus, Martin

    2015-01-01

    This paper presents an extension system to a closed-source, real-time physics engine for improving structured stacking behavior with small-scale objects such as wooden toy bricks. The proposed system was implemented and evaluated. The tests showed that the system is able to simulate several common...

  17. A review of skin conditions in modern warfare and peacekeeping operations.

    Science.gov (United States)

    Gelman, Ari B; Norton, Scott A; Valdes-Rodriguez, Rodrigo; Yosipovitch, Gil

    2015-01-01

    Skin is the most exposed organ of the body, and military personnel face many external skin threats. As a result, skin disease is an important source of morbidity among military personnel deployed on combat or peacekeeping operations. This article reviews the most common conditions seen by deployed military dermatologists. A PubMed search was used to identify articles in English, written between 1965 and 2014, using medical subject headings "military medicine" AND "skin disease" or "military personnel" AND "skin disease." The five most common reasons for physician consultation for skin conditions in wartime since the Vietnam War were warts (10.7%), fungal infections (10.4%), acne (9.0%), nonspecific eczematous conditions (7.1%), and sexually transmitted diseases (6.1%). There was a significant difference in the skin conditions seen in the hot and humid climates of Vietnam and East Timor, where bacterial and fungal infections were more common reasons for consultation, and the dry climates of Bosnia and Iraq, where eczematous conditions made up a larger part of the dermatologic caseload. Reprint & Copyright © 2015 Association of Military Surgeons of the U.S.

  18. Apparatus and method for non-invasive diagnosis and control of motor operated valve condition

    Science.gov (United States)

    Lyon, R.H.; Chai, J.; Lang, J.H.; Hagman, W.H.; Umans, S.D.; Saarela, O.J.

    1997-01-14

    An apparatus compares the torque from an MOV motor with the valve displacement, and from the comparison assesses MOV operating condition. A transducer measures the vibration of the housing of an MOV. The vibrations are due to the motions of the rotating elements within the housing, which motions are directly related to the motion of the valve relative to its seat. Signal processing apparatus analyzes the vibrations to recover the rotations of the rotating elements and thus the motion of the valve plug. Lost motion can also be determined (if a lost motion connection exists) by demodulating the vibration signal and thus taking into account also the lost motion. Simultaneously, the forces applied to the valve are estimated by estimating the torque between the stator and the rotor of the motor. Such torque can be estimated from measuring the input current and voltage alone, using a forgetting factor and a correction for the forgetting factor. A signature derived from relating the torque to the valve position can be used to assess the condition of the MOV, by comparing the signature to signatures for MOVs of known conditions. The vibration analysis components generate signals that relate to the position of elements in the operator. Similarly, the torque estimator estimates the torque output by any type of electric motor, whether or not part of an MOV analysis unit. 28 figs.

  19. 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.

  20. 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, ...

  1. Prediction of knock limited operating conditions of a natural gas engine

    International Nuclear Information System (INIS)

    Soylu, Seref

    2005-01-01

    Computer models of engine processes are valuable tools for predicting and analyzing engine performance and allow exploration of many engine design alternatives in an inexpensive fashion. In the present work, a zero-dimensional, two zone thermodynamic model was used to determine the knock limited operating conditions of a natural gas engine. Experimentally based burning rate models were used for flame initiation and propagation calculations. A knock model was incorporated with the zero-dimensional model. Comparison of the measured and calculated cylinder pressure data indicated that the model is able to match the measured cylinder pressure data with less than 8% error in magnitudes if the computations are started at the experimental spark timing. The knock predictions agreed with the measurements also. With the established knock model, it is possible not only to investigate whether knock is observed with changing operating and design parameters, but also to evaluate their effects on the maximum possible knock intensity

  2. 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 O 2 /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.

  3. Operating experience with the 50 MeV 10kA ATA power conditioning system

    International Nuclear Information System (INIS)

    Rogers, D.; Lee, F.D.; Newton, M.; Reginato, L.L.; Smith, M.E.

    1984-06-01

    The Advanced Test Accelerator (ATA) has been operational for over one year and has achieved full parameters in the power conditioning system. The pulsed power system has been previously described, however, during the past year of operation a considerable amount of statistical data has been accumulated on the 211 gas blown spark gaps that perform the main switching function in the ATA. These spark gaps were designed for 250kV, 40 kA and 70ns pulse. The parameter that made this spark gap somewhat unique was the requirement that it be able to provide a burst of ten pulses at one kilohertz with an average repetition rate of 5Hz. 2 references, 7 figures

  4. Wear behavior of steam generator tubes in nuclear power plant operating condition

    International Nuclear Information System (INIS)

    Kim, In-Sup; Hong, Jin-Ki; Kim, Hyung-Nam; Jang, Ki-Sang

    2003-01-01

    Reciprocating sliding wear tests were performed on steam generator tubes materials at steam generator operating temperature. The material surfaces react with oxygen to form oxides. The oxide properties such as formation rate and mechanical properties are varied with the test temperature and alloy composition. So, it is important to investigate the wear properties of each steam generator tube materials in steam generator operating condition. The tests results indicated that the wear coefficient in work rate model of alloy 690 was faster than that of alloy 800. From the scanning electron microscopy observation, the wear scars were similar each other and worn surfaces were covered with oxide layers. It seemed that the oxide layers were formed by wear debris sintering or cold welding and these layer properties affected the wear rate of steam generator tube materials. (author)

  5. Influence of the condition of the airfield pavement structures on the operation safety of aircraft

    Directory of Open Access Journals (Sweden)

    Wesołowski Mariusz

    2017-06-01

    Full Text Available The structure of the airfield pavement is a set of layers, whose task is to take over and transfer loads from moving aircraft to a ground subsoil in a safety manner. Airfield pavements are designed for a specific period of operation, assuming the forecasted intensity and the structure of the air traffic. The safety of air operations executed by the aircraft on airfield pavements depends primarily on the condition of their structure’s load capacity. In order to assess the load capacity of airfield pavements, the method ACN-PCN, which was introduced by the International Civil Aviation Organization ICAO and according to which the load capacity of the airfield pavement is expressed with the PCN index, is applied.

  6. [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.

  7. Adaptation of continuous biogas reactors operating under wet fermentation conditions to dry conditions with corn stover as substrate.

    Science.gov (United States)

    Kakuk, Balázs; Kovács, Kornél L; Szuhaj, Márk; Rákhely, Gábor; Bagi, Zoltán

    2017-08-01

    Corn stover (CS) is the agricultural by-product of maize cultivation. Due to its high abundance and high energy content it is a promising substrate for the bioenergy sector. However, it is currently neglected in industrial scale biogas plants, because of its slow decomposition and hydrophobic character. To assess the maximum biomethane potential of CS, long-term batch fermentations were carried out with various substrate concentrations and particle sizes for 72 days. In separate experiments we adapted the biogas producing microbial community in wet fermentation arrangement first to the lignocellulosic substrate, in Continuous Stirred Tank Reactor (CSTR), then subsequently, by continuously elevating the feed-in concentration, to dry conditions in solid state fermenters (SS-AD). In the batch tests, the produce 90% of the total biomethane yield than the amount of substrate added to the fermentation lowered the specific methane yield. In the CSTR experiment, the daily substrate loading was gradually increased from 1 to 2 g vs /L/day until the system produced signs of overloading. Then the biomass was transferred to SS-AD reactors and the adaptation process was studied. Although the specific methane yields were lower in the SS-AD arrangement (177 mL CH 4 /g vs in CSTR vs. 105 mL in SS-AD), the benefits of process operational parameters, i.e. lower energy consumption, smaller reactor volume, digestate amount generated and simpler configuration, may compensate the somewhat lower yield. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  8. The influences of operating conditions and design configurations on the performance of symmetric electrochemical capacitors.

    Science.gov (United States)

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

    2016-10-19

    The influence of different charging current densities, charging times and several structural designs on symmetric electrochemical capacitor (EC) performance, including capacitance, energy density and power density, has been investigated via modelling and simulation. Understanding the effects of different operating conditions and structural design variables on a capacitor's performance will guide in the optimal design and fabrication of high performance ECs. The operating conditions and design configurations examined were charging current density, charging times, electrode and electrolyte effective conductivity, electrode thickness and electrode porosity. The results reveal that ECs with low electrode and electrolyte effective conductivities can only be effectively charged at low current density for long times. ECs with a high concentration of impurity ions or redox species exhibit high self-discharge rates, and fast charging of the ECs greatly reduces the self-discharge rate, compared to slow charging, provided that the effective conductivities of the electrode and electrolyte are high enough. The simulation showed the typical electrode length scale over which the liquid potential drop occurs and electrode utilization can be employed as a design parameter to optimize electrode thickness (effective thickness) for ECs designed to operate under a specific current density range. The expression for electrode utilization (u) and the guidelines that can also be used to determine optimum electrode thickness/effective thickness (100% electrode utilization), optimum charging time and optimum current density in a cell of a given voltage and effective conductivity of electrode and electrolyte, were derived. The energy and power density of ECs were increased when the electrode thickness was reduced in the given charging conditions. The Ragone plots can be used to select optimum electrode dimensions to attain given energy and power density specifications.

  9. Pressurized electrolysis stack with thermal expansion capability

    Science.gov (United States)

    Bourgeois, Richard Scott

    2015-07-14

    The present techniques provide systems and methods for mounting an electrolyzer stack in an outer shell so as to allow for differential thermal expansion of the electrolyzer stack and shell. Generally, an electrolyzer stack may be formed from a material with a high coefficient of thermal expansion, while the shell may be formed from a material having a lower coefficient of thermal expansion. The differences between the coefficients of thermal expansion may lead to damage to the electrolyzer stack as the shell may restrain the thermal expansion of the electrolyzer stack. To allow for the differences in thermal expansion, the electrolyzer stack may be mounted within the shell leaving a space between the electrolyzer stack and shell. The space between the electrolyzer stack and the shell may be filled with a non-conductive fluid to further equalize pressure inside and outside of the electrolyzer stack.

  10. Performance evaluation of free piston compressor coupling organic Rankine cycle under different operating conditions

    International Nuclear Information System (INIS)

    Han, Yongqiang; Kang, Jianjian; Zhang, Guangpan; Liu, Zhongchang; Tian, Jing; Chai, Jiahong

    2014-01-01

    Highlights: • An ORC-FPC is proposed to recover the waste heat of exhaust gas. • The simulation model has been established in GT-Suite ver. 7.0. • Performances of ORC-FPC under different operating conditions have been evaluated. • Performances prediction of the ORC-FPC for real application has been made in the paper. - Abstract: An organic Rankine cycle coupling free piston compressor (ORC-FPC) system has been proposed, which is used in recovering the waste heat of exhaust gas from the stationary compressed nature gas (CNG) fueled internal combustion compressor. The free piston compressor functions as an expander in ORC and operates reciprocally to compress natural gas in compression cylinders to demanded pressure. After capturing the waste heat available and turning into vapor in evaporator, the working fluid R245ca can provide power to drive the free piston moving reciprocally in expander. The model of ORC-FPC built up in the GT-suite ver. 7.0 assists evaluating performances of this system under different operating conditions. In this paper, the operating condition includes two aspects: thermodynamic state of working fluid and input power. The purpose of simulation based on the model is to specify appropriate thermodynamic states of working fluid which yield high value of η (the ratio of work produced by the power piston to enthalpy reduction of working fluid in the power cylinder) and k (the ratio of output CNG’s mass to enthalpy reduction of working fluid in the power cylinder) value. Performances of the ORC-FPC under different input power, which determined by the operating frequency and injection quantity of the heated working fluid, have also been evaluated. Results show that when the heated working fluid is at 11.5 bar and 383 K, the system achieves better performances than other thermodynamic states, of which k is 601.1 mg/kJ and η is 44.3%. Based on the optimum thermodynamic state and the principle of obtaining the maximum k, the specific input

  11. The effect of operational conditions on the sludge specific methanogenic activity and sludge biodegradability

    International Nuclear Information System (INIS)

    Leitao, R. C.; Santaella, S. T.; Haandel, A. C. van; Zeeman, G.; Lettinga, G.

    2009-01-01

    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 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)

  12. 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)

  13. Integral criterion of mining machines technical condition level at their operation

    Science.gov (United States)

    Ivanov, S. L.; Shishkin, P. V.

    2017-10-01

    Nowadays classification of systems of equipment maintenance and repair (M&R), in particular, mining machines, has a wide range. However, existing systems of maintenance and repair have their own disadvantages like resource-intensiveness and cost, lack of guarantees to prevent emergency failures. In order to reduce the costs for carrying out M&R, the service system CM&R (Conscientious Maintenance and Repair) was offered, which is focused on the tendency to achieve zero emergency failures, to reduce costs and to achieve the maximum possible effectiveness of the object functioning in actual operating conditions. A unified integrated indicator of the degree of object’s degradation has been offered.

  14. 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. Published by Elsevier Inc.

  15. Analysis of the influence of operating conditions on fouling rates in fired heaters

    International Nuclear Information System (INIS)

    Morales-Fuentes, A.; Picón-Núñez, M.; Polley, G.T.; Méndez-Díaz, S.

    2014-01-01

    Fouling due to chemical reaction in preheat trains for the processing of crude oil plays a key role in the operation and maintenance costs and on greenhouse emissions to atmosphere in crude processing plants. A preheat train consists of a set of heat transfer units that provide the crude oil stream the required amount of thermal energy to reach its target temperature either by heat recovery or by direct firing. Fired heaters supply external high temperature heating through the burning of fuel which result in complex heat transfer processes due to the large temperature and pressure changes and vaporization that takes place inside the unit. In this work, a thermo-hydraulic analysis of the performance of fired heaters is carried out through the application of commercial software to solve the mathematical models using finite difference methods; the analysis is applied to the crude side of a vertical fired heater in order to evaluate the impact of process conditions such as throughput and crude inlet temperature (CIT) on the fouling that take place at the early stages of operation. Using a fouling rate model based on thermo-hydraulic parameters, fouling rates are predicted assuming steady state operation and clean conditions. Although variations in process conditions are known to influence fouling rates, little work has been done on the subject. In this work excess air and steam injection are studied as a means to mitigate fouling. Results show that throughput reduction brings about a marked increase in the fouling rates. A decrease in CIT affects only the convection zone and it is found that this effect is negligible. In terms of excess air, it is found that although it affects negatively the heater efficiency it can be used to balance heat transfer between the convection and radiation zone in a way that fouling rates are reduced; however this strategy should be considered right from the design stage. Finally it is observed that steam injection is an effective method

  16. Influence of thermal charge preparation on coke comminution under blast-furnace operating conditions

    Energy Technology Data Exchange (ETDEWEB)

    Shkoller, M.B.; Dinel' t, V.M.; Korchuganova, G.S.; Petrov, V.B.

    1983-01-01

    An investigation is described for the study of structural breakdown of coke by thermochemical action of alkali and alkaline-earth metal vapors under blast furnace operating conditions. Bench-scale test facilities are described in which a pair of coke samples are exposed to the metal vapors then subjected to gasification. Structural strength tests were performed before and after each experiment. Coke samples were obtained in either moist or thermally prepared condition. The value of thermal charge preparation (heat treatment of the coal at 150/sup 0/C in a fluidized bed) was established, since it shifts the pore size distribution to the smaller size, thereby retarding adsorption of the metal vapors. 16 references, 4 figures, 2 tables.

  17. Characterizing (rating) the performance of large photovoltaic arrays for all operating conditions

    Energy Technology Data Exchange (ETDEWEB)

    King, D.L. [Sandia National Labs., Albuquerque, NM (United States); Eckert, P.E. [Arizona Public Service Co., Phoenix, AZ (United States)

    1996-06-01

    A new method has been developed for characterizing the electrical performance of photovoltaic arrays. The method provides both a ``rating`` at standard reporting conditions and a rigorous yet straightforward model for predicting array performance at all operating conditions. For the first time, the performance model handles the influences of irradiance, module temperature, solar spectrum, solar angle-of-incidence, and temperature coefficients, in a practical way. Validity of the procedure was confirmed during field testing of a 25-kW array recently installed by Arizona Public Service Co. on Carol Spring Mountain (which powers microwave, ceullular phone, and TV communictions equipment). This paper describes the characterization procedure, measured array performance, and the predictive model.

  18. Effects of cutting conditions on forces and force coefficients in plunge milling operations

    Directory of Open Access Journals (Sweden)

    Francesco Rafanelli

    2015-06-01

    Full Text Available The modeling of milling forces is a crucial issue to understand milling processes. In the literature, many force models and experiments to identify force coefficients are found. The objective of this article is to develop a new approach, based on the traditional average force method, able to measure and compute the cutting coefficients for end mills used in plunging operations. This model has been used to evaluate the effect of the radial engagement on the cutting coefficients themselves, proposing a new strategy to update these values for different cutting parameters. This dependency of the cutting coefficient is particularly important for the determination of the stability lobe diagrams, used to predict the chatter conditions. In this article, the method to assess the cutting coefficients, the results of the experimental tests, and the effect of condition-dependent cutting coefficients on process stability are presented.

  19. Effect of catalyst properties and operating conditions on hydroprocessing high metals feeds

    Energy Technology Data Exchange (ETDEWEB)

    Pazos, J.M.; Gonzalez, J.C.; Saluzar-Gullen, A.J.

    1983-10-01

    Catalytic hydroprocessing of high metals heavy oils, containing over 480 ppm Ni + V, was carried out in trickle bed pilot units. The analyses of the used catalysts (coke, metals content, and vanadium distribution) were correlated with the deactivation runs. The deactivation by coke is very much dependent on the catalyst physical properties (mean pore diameter), rather than on the chemical properties, and on the nature of the feed. As metals removal is a diffusion-controlled reaction, catalysts and operating conditions that increase the Thiele modulus, e.g., high activity and small pore catalysts, high hydrogen pressures and temperatures, show a stronger deactivation by feed metals. In this case, most of the vanadium was deposited in the outer edge of the catalyst particle. Unconventional vanadium profiles along the reactor length were obtained under certain conditions. Based on these data, a kinetic model was proposed which considers that demetallization is a complex reaction that occurs through a series of consecutive and parallel reactions.

  20. 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.

  1. 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.

  2. Activity of the RA Reactor Physics group in 1980 - Definition of the Operation conditions for future safe and economical RA reactor operation with 80% enriched fuel

    International Nuclear Information System (INIS)

    Martinc, R.

    1980-01-01

    During 1980. the RA reactor was not in operation. That is why this period was devoted to definition of operating conditions for further reactor operation with 80% enriched fuel. The fuel elements which were in the core at the moment of shutdown in March 1979will not be used again (388 80% enriched fuel elements, and 511 2% enriched fuel elements). The reactor will be operated only with 80% enriched fuel, staring with initiat core configuration with 440 elements on the borders gradually changing to equi;librium core with 720 fuel elements. The analyses were concerned with safety issues of future operation [sr

  3. Radiation Measurements Laboratory (RML) calibration and assessment of the ATR SPING-3 stack effluent monitor

    International Nuclear Information System (INIS)

    Koeppen, L.D.; Rogers, J.W.; Simpson, O.D.

    1983-12-01

    An evaluation, calibration and assessment of the Eberline SPING-3 ATR stack effluent monitor was conducted. This unit which monitors particulate, iodine and noble gas effluents was producing abnormal results following the initial installation and operational testing. The purposes of this work were to find the causes of the abnormal results and correct them if possible; check the calibrations and adjust them if necessary; and to provide a better in-depth understanding of what the unit is monitoring and how well it performs under this application. Results have shown that there were some problems associated with the unit as initially installed and tested. These problems have been identified and suggested alternatives shown, the monitor was found to be applicable to some extent under the current conditions. The calibrations have been checked and adjustments made. More operation testing and evaluation is needed to assess how well this works under a variety of ATR operating conditions. 2 references, 10 figures, 3 tables

  4. Efficacy of a prehospital self-expanding polyurethane foam for noncompressible hemorrhage under extreme operational conditions.

    Science.gov (United States)

    Rago, Adam P; Larentzakis, Andreas; Marini, John; Picard, Abby; Duggan, Michael J; Busold, Rany; Helmick, Marc; Zugates, Greg; Beagle, John; Sharma, Upma; King, David R

    2015-02-01

    Noncompressible abdominal hemorrhage is a significant cause of battlefield and civilian mortality. We developed a self-expanding polyurethane foam intended to provide temporary hemorrhage control and enable evacuation to a definitive surgical capability, for casualties who would otherwise die. We hypothesized that foam treatment would be efficacious over a wide range of out-of-hospital operational conditions. The foam was tested in an established lethal, closed-cavity hepatoportal injury model in four groups as follows. Group 1 involved baseline conditions, wherein foam was deployed from a pneumatically driven, first-generation delivery device at room temperature (n = 6). Group 2 involved foam deployment from a field-relevant, handheld delivery prototype (n = 12). Group 3 involved foam components that were conditioned to simulate 1-year shelf-life (n = 6). Group 4 involved foam that was conditioned to a range of temperatures (10 °C and 50 °C; n = 6 per group). In all studies, survival was monitored for up to 180 minutes and compared with an ongoing and accumulating control group with no intervention (n = 14). In Group 1 with a first-generation delivery system, foam treatment resulted in a significant survival advantage relative to the control group (p foam groups was significantly lower than in the control group (p foam treatment resulted in a survival advantage relative to the control group. This supports the feasibility of foam treatment as a prehospital hemostatic bridge to surgery for severely bleeding causalities.

  5. Stack semantics of type theory

    DEFF Research Database (Denmark)

    Coquand, Thierry; Mannaa, Bassel; Ruch, Fabian

    2017-01-01

    We give a model of dependent type theory with one univalent universe and propositional truncation interpreting a type as a stack, generalizing the groupoid model of type theory. As an application, we show that countable choice cannot be proved in dependent type theory with one univalent universe...

  6. Adding large EM stack support

    KAUST Repository

    Holst, Glendon

    2016-12-01

    Serial section electron microscopy (SSEM) image stacks generated using high throughput microscopy techniques are an integral tool for investigating brain connectivity and cell morphology. FIB or 3View scanning electron microscopes easily generate gigabytes of data. In order to produce analyzable 3D dataset from the imaged volumes, efficient and reliable image segmentation is crucial. Classical manual approaches to segmentation are time consuming and labour intensive. Semiautomatic seeded watershed segmentation algorithms, such as those implemented by ilastik image processing software, are a very powerful alternative, substantially speeding up segmentation times. We have used ilastik effectively for small EM stacks – on a laptop, no less; however, ilastik was unable to carve the large EM stacks we needed to segment because its memory requirements grew too large – even for the biggest workstations we had available. For this reason, we refactored the carving module of ilastik to scale it up to large EM stacks on large workstations, and tested its efficiency. We modified the carving module, building on existing blockwise processing functionality to process data in manageable chunks that can fit within RAM (main memory). We review this refactoring work, highlighting the software architecture, design choices, modifications, and issues encountered.

  7. A semi-empirical voltage degradation model for a low-pressure proton exchange membrane fuel cell stack under bus city driving cycles

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Languang; Ouyang, Minggao; Huang, Haiyan; Pei, Pucheng; Yang, Fuyuan [State Key Laboratory of Automotive Safety and Energy, Tsinghua University, Beijing 100084 (China)

    2007-01-10

    A voltage degradation model for the low-pressure proton exchange membrane fuel cell (PEMFC) stack used in a fuel cell bus is presented: (1) the oxygen concentration term was derived from the PEMFC output voltage equation, and the concept of oxygen concentration resistance coefficient was introduced; (2) a 5kW low-pressure PEMFC stack was used in this study. Two similar tests were carried out before and after the stack operating in the driving cycle for 640h. First, the ohmic losses under different temperatures were measured using the current interrupt method and formulized with linear fitting method. Then, the oxygen concentration term was studied by the experiments with different air stoichiometric ratios while keeping the other operating parameters unchanged. The oxygen concentration resistance coefficient was obtained from the difference of voltages for the PEMFC stack in different air stoichiometric ratios using the genetic optimization algorithm. Then, the activation loss was obtained based on the PEMFC output voltage, the ohmic loss, and the concentration loss. The degradation model of the stack was built finally by comparing the two test results; (3) the correlation of the model to the actual experimental data is good; (4) the overvoltage of the stack with aging was analyzed using this model. The analysis showed that the activation overvoltage dominated the stack loss with about 80% of the total losses, followed by the ohmic loss. The concentration loss almost does not change with aging in the driving cycle condition; (5) the comparison of the simulation with the actual data from the PEMFC bus running for 30,000km indicated that after 36,000km the rated power of the PEMFC bus must be reduced. (author)

  8. 47 CFR 90.1432 - Conditions for waiver to allow limited and temporary wideband operations in the 700 MHz public...

    Science.gov (United States)

    2010-10-01

    ... wideband operations, public safety entities may request a waiver to operate in the upper 1.25 megahertz of... that rejected responses to the required broadband network RFP were more costly, provided less coverage... spectrum will be subject to the following conditions: (i) All devices operating on the wideband system must...

  9. 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.

  10. Aerodynamic performance of a vibrating piezoelectric fan under varied operational conditions

    International Nuclear Information System (INIS)

    Stafford, J; Jeffers, N

    2014-01-01

    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.

  11. 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.

  12. Mathematical model and computer code for coated particles performance at normal operating conditions

    International Nuclear Information System (INIS)

    Golubev, I.; Kadarmetov, I.; Makarov, V.

    2002-01-01

    Computer modeling of thermo-mechanical behavior of coated particles during operating both at normal and off-normal conditions has a very significant role particularly on a stage of new reactors development. In Russia a big experience has been accumulated on fabrication and reactor tests of CP and fuel elements with UO 2 kernels. However, this experience cannot be using in full volume for development of a new reactor installation GT-MHR. This is due to very deep burn-up of the fuel based on plutonium oxide (up to 70% fima). Therefore the mathematical modeling of CP thermal-mechanical behavior and failure prediction becomes particularly important. The authors have a clean understanding that serviceability of fuel with high burn-ups are defined not only by thermo-mechanics, but also by structured changes in coating materials, thermodynamics of chemical processes, 'amoeba-effect', formation CO etc. In the report the first steps of development of integrate code for numerical modeling of coated particles behavior and some calculating results concerning the influence of various design parameters on fuel coated particles endurance for GT-MHR normal operating conditions are submitted. A failure model is developed to predict the fraction of TRISO-coated particles. In this model it is assumed that the failure of CP depends not only on probability of SiC-layer fracture but also on the PyC-layers damage. The coated particle is considered as a uniform design. (author)

  13. 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.

  14. Extreme Production Conditions of Photovoltaic Power Plant Operated in Distribution Grid

    Directory of Open Access Journals (Sweden)

    Martin Smocek

    2014-01-01

    Full Text Available Photovoltaic power plants are sources of electrical energy that are very dependent on weather conditions. This paper interests in description of stochastic production of power in photovoltaic power plants and subsequently its impact on the distribution power grid. Stochastic production of power from these sources is considerable and hardly predictable. The aim of this survey is to assess the influence of photovoltaic power plants operation on the daily load diagram with regard to output change difference of active power at the relevant substation. Evaluation is based on real-time synchronous data measuring both on-site photovoltaic power plant operation and on-site electric power line output from the substation. This measurement is used for suggestion of a general calculation methodology for the assessment of the difference of active power at a particular node of the grid under various power changes from the photovoltaic power plant. Statistical methods have been employed to process a methodology in order establish extreme conditions of production power for photovoltaic power plant.

  15. 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.

  16. Design retrofit to prevent damage due to heat transport pump operation under conditions of significant void

    International Nuclear Information System (INIS)

    Lam, K.F.

    1991-01-01

    The purpose of this paper is to provide a general review of certain key design areas which address the safety concerns of HT pump operation under conditions of significant void. To illustrate the challenges confronting designers and analysts, some of the highlights during the design of a protective system to prevent damage to HT piping and pump supports at Bruce NGS 'A' are outlined. The effects of this protective system on reactor safety are also discussed. HI pump operation under conditions of significant void offers a major challenge to designers and analysts to ensure that pump induced vibration and its effects on pump and piping are addressed. For an in-service station the search for a practical solution is often limited by existing. station equipment design and Layout. The diversity of design verification process requires a major commitment of engineering resources to ensure all. safety aspects meet the requirements of regulatory body. Work currently undertaken at Ontario Hydro Research Pump Test Complex on two-phase flow in pumps and piping may provide better prediction of vibration characteristics so that inherent conservativeness in fatigue Life prediction of HI system components can be reduced

  17. The study of operating an air conditioning system using Maisotsenko-Cycle

    Science.gov (United States)

    Khan, Mohammad S.; Tahan, Sami; Toufic El-Achkar, Mohamad; Abou Jamus, Saleh

    2018-03-01

    The project aims to design and build an air conditioning system that runs on the Maisotsenko cycle. The system is required to condition and cool down ambient air for a small residential space with the reduction in the use of electricity and eliminating the use of commercial refrigerants. This project can operate at its optimum performance in remote areas like oil diggers and other projects that run in the desert or any site that would not have a very high relative humidity level. The Maisotsenko cycle is known as the thermodynamic concept that captures energy from the air by using the psychometric renewable energy available in the latent heat in water evaporating in air. The heat and mass exchanger design was based on choosing a material that would-be water resistant and breathable, which was found to be layers of cardboard placed on top of each other and thus creating channels for air to pass through. Aiming for this design eliminates any high power electrical equipment such as compressors, condensers and evaporators that would be used in an AC system with the exception of a 600 W blower and a 10 W fan, thus making it a more environmentally friendly project. Moreover, the project is limited by the ambient temperature and humidity, as the model operates at an optimum when the relative humidity is lower.

  18. Computer Simulation of Complex Power System Faults under various Operating Conditions

    International Nuclear Information System (INIS)

    Khandelwal, Tanuj; Bowman, Mark

    2015-01-01

    A power system is normally treated as a balanced symmetrical three-phase network. When a fault occurs, the symmetry is normally upset, resulting in unbalanced currents and voltages appearing in the network. For the correct application of protection equipment, it is essential to know the fault current distribution throughout the system and the voltages in different parts of the system due to the fault. There may be situations where protection engineers have to analyze faults that are more complex than simple shunt faults. One type of complex fault is an open phase condition that can result from a fallen conductor or failure of a breaker pole. In the former case, the condition is often accompanied by a fault detectable with normal relaying. In the latter case, the condition may be undetected by standard line relaying. The effect on a generator is dependent on the location of the open phase and the load level. If an open phase occurs between the generator terminals and the high-voltage side of the GSU in the switchyard, and the generator is at full load, damaging negative sequence current can be generated. However, for the same operating condition, an open conductor at the incoming transmission lines located in the switchyard can result in minimal negative sequence current. In 2012, a nuclear power generating station (NPGS) suffered series or open phase fault due to insulator mechanical failure in the 345 kV switchyard. This resulted in both reactor units tripping offline in two separate incidents. Series fault on one of the phases resulted in voltage imbalance that was not detected by the degraded voltage relays. These under-voltage relays did not initiate a start signal to the emergency diesel generators (EDG) because they sensed adequate voltage on the remaining phases exposing a design vulnerability. This paper is intended to help protection engineers calculate complex circuit faults like open phase condition using computer program. The impact of this type of

  19. Particle number and particulate mass emissions of heavy duty vehicles in real operating conditions

    Directory of Open Access Journals (Sweden)

    Rymaniak Lukasz

    2017-01-01

    Full Text Available The article investigates the issue of PM emissions from HDV vehicles. The theoretical part discusses the problem of emission of this toxic compound in terms of particle structure taking into account the mass and dimensions of PM. Next, the methodology of the research and the results of the measurements performed under the conditions of actual operation were presented. The test drive routes were chosen in accordance with the operational purpose of the selected test vehicles. Two heavy vehicles were used for the study: a tractor with trailer and an eighteen meter long city bus. The test vehicles complied with the Euro V standard, with the second vehicle additionally complying with the EEV standard and being equipped with a DPF. The analysis of the research results was performed in the aspect of determining the operating time densities of vehicles and their drive systems as well as defining their emission characteristics and ecological indicators. PM and PN emissions were measured in the tests and particle size distribution was determined. It was shown that the exhaust gas after treatment system used in the city bus had a positive influence on the ecological indicators and had contributed to the reduction of PN emissions for heavier particles.

  20. Advanced development and operating experience with a canned motor pump under pressurized water reactor conditions

    International Nuclear Information System (INIS)

    Dittmer, H.; Reymann, A.; Seibig, B.; Reinecker, H.

    1988-01-01

    At the research reactor FRG-2, Geesthacht, an irradiation device is in operation for testing defective light-water-reactor (LWR) test fuel rods under pressurized water reactor conditions (320 0 C, 160 bar). The requirements to the canned motor pump for cooling water circulation: medium: Demineralized water, operating temperature 320 0 C, operating pressure 155 bar, radiation field of the reactor, integration in the irradiation capsule, helium leak rate -6 mbar.dm 3 .s -1 , minimum working life 3000 hours, were high and caused difficulties in the acquisition of this component. First test runs with supplied pumps showed that the desired working life could not be achieved. The results of the development steps, the test runs, and the performance in service show that for our range of applications, the best combination of materials for the radial bearings is silicon-infiltrated SiC (8% free Si) against the same material. These bearings allowed a good working life for the pump to be achieved. (orig./GL) [de

  1. The pulse tube engine: A numerical and experimental approach on its design, performance, and operating conditions

    International Nuclear Information System (INIS)

    Moldenhauer, Stefan; Stark, Tilman; Holtmann, Christoph; Thess, André

    2013-01-01

    The pulse tube engine is a simple heat engine based on the pulse tube process. Due to its simplicity it has a high potential to be applicable in waste heat usage and energy harvesting purposes. In this work, mathematical and experimental design tools are developed to study a pressurized laboratory scale pulse tube engine. The mathematical model is based on the transient numerical solution of the governing differential equations for mass, momentum and energy. The Modelica environment of SimulationX is used to solve the equations numerically and the model is employed to design the experimental test engine with helium as working fluid. The transient behavior of the pulse tube engine's underlying thermodynamic properties is studied numerically and experimentally under different design parameters as well as for different heat input temperatures, filling pressures and operating frequencies. The measured engine characteristics are compared with the calculated predictions. Internal and external power losses are quantified. Design studies for a further development of the pulse tube engine are performed experimentally. The developed numerical tool provides a rational framework for up-scaling the current laboratory model to industrial scale. - Highlights: • We developed a mathematical model and an experimental test engine to study the pulse tube engine. • The experimental test engine is able to operate with pressurized helium of up to 12 bar filling pressure. • We characterized and compared the engine's behavior under different design features and operating conditions. • Design studies for a further development of the pulse tube engine are performed experimentally

  2. 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

  3. Efficiency Evaluation of Open-Loop GHPS Operation Under Various Hydrogeological Conditions

    Science.gov (United States)

    Lee, S.; Kim, S.; Bae, G.; Lee, K.

    2008-12-01

    Geothermal heat pump system (GHPS) can be cost-effective renewable energy sources. In order to develop the GHPS which has certain hydrogeological characteristics, understanding the thermohydraulic process of an aquifer is necessary for effective usage of open-loop GHPS. Experimental and numerical tests are performed for two concepts of open-loop GHPS: simple open-loop and energy storage concept. In simple open-loop sets, tests were performed fixing the locations of pumping and injection wells. In contrast, tests in energy storage sets were conducted by changing the locations of wells in a seasonal cycle. Experimental test using sand tank was performed only for the simple open-loop concept, while numerical tests were performed for the both concepts. Numerical modeling results using FEFLOW were compatible with the experimental results. In the simple open-loop sets, the temporal temperature change in a pumping well was measured. Effective operation conditions are obtained with high hydraulic conductivity (3X10-3 m/s) and long distance (60 cm) between wells on hydraulic gradient 0.025 because the effect of injected water temperature must be minimized. In the energy storage sets, thermal recovery factors (R) under various conditions were calculated to evaluate the efficiency. Low hydraulic conductivity (3X10-5 m/s), hydraulic gradient 0.0 and long well distance (more than 20 m) are the best conditions for operation efficiency (R=37.92) because faster groundwater flow lead to advection or down-gradient `drift' of stored energy beyond potential recovery regions. In the case of two-layered aquifer, the porosity and groundwater flow characteristics of each layer sensitively affected the migration of thermal plume. Two-layered aquifer with the top-layer of low hydraulic conductivity (3X10-5 m/s) and porosity (0.2) is profitable for the effective open-loop GHPS operation under hydraulic gradient 0.0 and well distance (20 m). The results from experimental and numerical tests

  4. Conditional Monthly Weather Resampling Procedure for Operational Seasonal Water Resources Forecasting

    Science.gov (United States)

    Beckers, J.; Weerts, A.; Tijdeman, E.; Welles, E.; McManamon, A.

    2013-12-01

    To provide reliable and accurate seasonal streamflow forecasts for water resources management several operational hydrologic agencies and hydropower companies around the world use the Extended Streamflow Prediction (ESP) procedure. The ESP in its original implementation does not accommodate for any additional information that the forecaster may have about expected deviations from climatology in the near future. Several attempts have been conducted to improve the skill of the ESP forecast, especially for areas which are affected by teleconnetions (e,g. ENSO, PDO) via selection (Hamlet and Lettenmaier, 1999) or weighting schemes (Werner et al., 2004; Wood and Lettenmaier, 2006; Najafi et al., 2012). A disadvantage of such schemes is that they lead to a reduction of the signal to noise ratio of the probabilistic forecast. To overcome this, we propose a resampling method conditional on climate indices to generate meteorological time series to be used in the ESP. The method can be used to generate a large number of meteorological ensemble members in order to improve the statistical properties of the ensemble. The effectiveness of the method was demonstrated in a real-time operational hydrologic seasonal forecasts system for the Columbia River basin operated by the Bonneville Power Administration. The forecast skill of the k-nn resampler was tested against the original ESP for three basins at the long-range seasonal time scale. The BSS and CRPSS were used to compare the results to those of the original ESP method. Positive forecast skill scores were found for the resampler method conditioned on different indices for the prediction of spring peak flows in the Dworshak and Hungry Horse basin. For the Libby Dam basin however, no improvement of skill was found. The proposed resampling method is a promising practical approach that can add skill to ESP forecasts at the seasonal time scale. Further improvement is possible by fine tuning the method and selecting the most

  5. 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.

  6. 296-B-5 Stack monitoring and sampling system annual system assessment report

    International Nuclear Information System (INIS)

    Ridge, T.M.

    1995-02-01

    The B Plant Administration Manual requires an annual system assessment to evaluate and report the present condition of the sampling and monitoring system associated with Stack 296-B-5 at B Plant. The sampling and monitoring system associated with stack 296-B-5 is functional and performing satisfactorily. This document is an annual assessment report of the systems associated with the 296-B-5 stack

  7. Effect of operation conditions on ammonia evolution in isothermal composting of sewage sludge

    International Nuclear Information System (INIS)

    Nishimura, Koichi; Watanabe, Hiromasa; Hashimoto, Shoji; Kawakami, Waichiro

    1985-07-01

    In the isothermal composting of sewage sludge, influences of operation conditions on NH 3 evolution were studied to obtain informations on the sludge deodorization during composting. The pattern of CO 2 evolution from the sludge was not affected by the aeration rate or the bulking agent. On the other hand, the pattern of NH 3 evolution was affected by the fermentation condition and the overall weight ratios of C in CO 2 to N in NH 3 , CO 2 -C/NH 3 -N in the total gas evolved varied with fermentation time. The ratios approached to almost constant values ranging from 5 to 7 in earlier stages at higher aeration rate or temperature. These facts mean that the change of NH 3 evolution pattern with fermentation conditions is due to NH 3 absorption by the sludge and the bulking agent, and actually, the NH 3 generation is a simultaneous process with CO 2 generation. Therefore, deodorization by composting can be completed at the end of fermentation. (author)

  8. 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...

  9. Rapid Integration of Artificial Sensory Feedback during Operant Conditioning of Motor Cortex Neurons.

    Science.gov (United States)

    Prsa, Mario; Galiñanes, Gregorio L; Huber, Daniel

    2017-02-22

    Neuronal motor commands, whether generating real or neuroprosthetic movements, are shaped by ongoing sensory feedback from the displacement being produced. Here we asked if cortical stimulation could provide artificial feedback during operant conditioning of cortical neurons. Simultaneous two-photon imaging and real-time optogenetic stimulation were used to train mice to activate a single neuron in motor cortex (M1), while continuous feedback of its activity level was provided by proportionally stimulating somatosensory cortex. This artificial signal was necessary to rapidly learn to increase the conditioned activity, detect correct performance, and maintain the learned behavior. Population imaging in M1 revealed that learning-related activity changes are observed in the conditioned cell only, which highlights the functional potential of individual neurons in the neocortex. Our findings demonstrate the capacity of animals to use an artificially induced cortical channel in a behaviorally relevant way and reveal the remarkable speed and specificity at which this can occur. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  10. Study on the flow reduction of forced flow superconducting magnet and its stable operation condition

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, Makoto [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment

    2001-03-01

    The forced flow superconducting coil especially made from a Cable-in-Conduit Conductor (CICC) is applied for large-scale devices such as fusion magnets and superconducting magnet energy storage (SMES) because it has high mechanical and electrical performance potential. The flow reduction phenomena caused by AC loss generation due to the pulsed operation was found based on the experimental results of three forced flow superconducting coils. And relation between the AC loss generation and flow reduction was defined from viewpoint of the engineering design and operation of the coils. Also the mechanism of flow reduction was investigated and stable operation condition under the flow reduction was clarified for forced flow superconducting coils. First, experiments of three different large-scale superconducting coils were carried out and experimental database of the flow reduction by AC loss generation was established. It was found experimentally that the flow reduction depends on the AC loss generation (W/m{sup 3}) in all of coils. It means the stable operation condition is defined not only the electro magnetism of superconducting coil but also flow condition. Mechanism of the flow reduction was investigated based on the experimental database. Hydraulics was applied to supercritical helium as a coolant. Also performances of the cryogenic pump by which coolant are supplied to the coil and friction of the superconductor as cooling path is considered for hydraulic estimation. The flow reduction of the coil is clarified and predictable by the equations of continuity, momentum and energy balance. Also total mass flow rate of coolant was discussed. The estimation method in the design phase was developed for total mass flow rate which are required under the flow reduction by AC losses. The friction of the superconductor and performance of cryogenic pump should be required for precise prediction of flow reduction. These values were obtained by the experiment data of coil and

  11. Multipole stack for the 4 rings of the PS Booster

    CERN Multimedia

    CERN PhotoLab

    1976-01-01

    The PS Booster (originally 800 MeV, now 1.4 GeV) saw first beam in 1972, routine operation began in 1973. The strive for ever higher intensities required the addition of multipoles. Manufacture of 8 stacks of multipoles was launched in 1974, for installation in 1976. For details, see 7511120X.

  12. Calculating the output distribution of stack filters that are erosion ...

    African Journals Online (AJOL)

    Two procedures to compute the output distribution ϕs of certain stack filters S (so called erosion-dilation cascades) are given. One rests on the disjunctive normal form of S and also yields the rank selection probabilities. The other is based on inclusion-exclusion and e.g. yields ϕs for some important LULU-operators S.

  13. A Novel Hybrid Actuator Driven Magnetically in the Bi-Cell PEM Fuel Cell Stack

    Directory of Open Access Journals (Sweden)

    Hsiaokang Ma

    2017-10-01

    Full Text Available This study develops an air breathing pump driven by a piezoelectric actuator for a proton exchange membrane fuel cell (PEMFC stack. Permanent magnets are combined with a piezoelectric actuator to drive three air breathing pumps using magnetic force. This design enables the pump to provide a sufficient amount of air simultaneously to six cathode flow field plates in a stack of three “bi-cell PZTmag–PEMFCs”. When both the PZTmag and the PDMSmag had a magnet with a 6-mm diameter and 1-mm thickness, a maximum amplitude of 87 μm was generated at 0.03 W of power under operating conditions of 70 Hz and 40 V. In computational fluid dynamics (CFD, when the nozzle and the diffuser of an air breathing pump have an aspect ratio of 13.13, air flow distributes uniformly inside the pump, thus allowing for uniform transmission of oxygen to the membrane electrode assembly. This aspect ratio was applied to the bi-cell PZTmag–PEMFC stack and yielded a maximum net power flux of 0.1925 W·cm−2, 20% higher than that reported in a previous study (Ma, 2013, with 68% and 76% less volume and weight, respectively.

  14. Topic Correlation Analysis for Bearing Fault Diagnosis Under Variable Operating Conditions

    Science.gov (United States)

    Chen, Chao; Shen, Fei; Yan, Ruqiang

    2017-05-01

    This paper presents a Topic Correlation Analysis (TCA) based approach for bearing fault diagnosis. In TCA, Joint Mixture Model (JMM), a model which adapts Probability Latent Semantic Analysis (PLSA), is constructed first. Then, JMM models the shared and domain-specific topics using “fault vocabulary” . After that, the correlations between two kinds of topics are computed and used to build a mapping matrix. Furthermore, a new shared space spanned by the shared and mapped domain-specific topics is set up where the distribution gap between different domains is reduced. Finally, a classifier is trained with mapped features which follow a different distribution and then the trained classifier is tested on target bearing data. Experimental results justify the superiority of the proposed approach over the stat-of-the-art baselines and it can diagnose bearing fault efficiently and effectively under variable operating conditions.

  15. Optimum operating conditions for a combined power and cooling thermodynamic cycle

    International Nuclear Information System (INIS)

    Sadrameli, S.M.; Goswami, D.Y.

    2007-01-01

    The combined production of thermal power and cooling with an ammonia-water based cycle proposed by Goswami is under intensive investigation. In the cycle under consideration, simultaneous cooling output is produced by expanding an ammonia-rich vapor in an expander to sub-ambient temperatures and subsequently heating the cool exhaust. When this mechanism for cooling production is considered in detail, it is apparent that the cooling comes at some expense to work production. To optimize this trade-off, a very specific coefficient-of-performance has been defined. In this paper, the simulation of the cycle was carried out in the process simulator ASPEN Plus. The optimum operating conditions have been found by using the Equation Oriented mode of the simulator and some of the results have been compared with the experimental data obtained from the cycle. The agreement between the two sets proves the accuracy of the optimization results

  16. Estimation of Operating Condition of Appliances Using Circuit Current Data on Electric Distribution Boards

    Science.gov (United States)

    Iwafune, Yumiko; Ogimoto, Kazuhiko; Yagita, Yoshie

    The Energy management systems (EMS) on demand sides are expected as a method to enhance the capability of supply and demand balancing of a power system under the anticipated penetration of renewable energy generation such as Photovoltaics (PV). Elucidation of energy consumption structure in a building is one of important elements for realization of EMS and contributes to the extraction of potential energy saving. In this paper, we propose the estimation method of operating condition of household appliances using circuit current data on an electric distribution board. Circuit current data are broken down by their shape using a self-organization map method and aggregated by appliance based on customers' information of appliance possessed. Proposed method is verified using residential energy consumption measurement survey data.

  17. 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.

  18. Reward-timing-dependent bidirectional modulation of cortical microcircuits during optical single-neuron operant conditioning.

    Science.gov (United States)

    Hira, Riichiro; Ohkubo, Fuki; Masamizu, Yoshito; Ohkura, Masamichi; Nakai, Junichi; Okada, Takashi; Matsuzaki, Masanori

    2014-11-24

    Animals rapidly adapt to environmental change. To reveal how cortical microcircuits are rapidly reorganized when an animal recognizes novel reward contingency, we conduct two-photon calcium imaging of layer 2/3 motor cortex neurons in mice and simultaneously reinforce the activity of a single cortical neuron with water delivery. Here we show that when the target neuron is not relevant to a pre-trained forelimb movement, the mouse increases the target neuron activity and the number of rewards delivered during 15-min operant conditioning without changing forelimb movement behaviour. The reinforcement bidirectionally modulates the activity of subsets of non-target neurons, independent of distance from the target neuron. The bidirectional modulation depends on the relative timing between the reward delivery and the neuronal activity, and is recreated by pairing reward delivery and photoactivation of a subset of neurons. Reward-timing-dependent bidirectional modulation may be one of the fundamental processes in microcircuit reorganization for rapid adaptation.

  19. Effect of plasma spray operating conditions on plasma jet characteristics and coating properties

    Science.gov (United States)

    Malmberg, S.; Heberlein, J.

    1993-12-01

    Using statistical design of experiments, the arc current, total gas flow rate, percent secondary gas (He), and powder feed rate have been varied to assess the torch behavior and establish its correlation to coating properties. The torch response includes arc voltage drop, torch efficiency, and plasma jet geometry. High-speed images of the luminous plasma jet for each operating condition have been acquired with a LaserStrobeℳ videocamera, and image analysis has been used to quantify the jet length and jet fluctuations as additional torch responses. Porosity and unmelted particles, which are determined using image analysis of a micrograph of a NiAl coating cross section, were selected as principal coating characteristics. These findings are expected to be useful for optimization of new spray processes and for evaluation of new torch designs.

  20. Tests of operating conditions for metrological application of HTS Josephson arrays

    International Nuclear Information System (INIS)

    Sosso, A; Lacquaniti, V; Andreone, D; Cerri, R; Klushin, A M

    2006-01-01

    We report on an experimental study of metrological properties of High Temperature Superconductor arrays, made of shunted bicrystal YBCO Josephson junctions, to assess their accuracy. A detailed analysis of measurement errors is presented, mainly based on a direct comparison of an HTS array against a low temperature array. Owing to the high sensitivity of the comparison, we were able to measure the changes in the HTS array voltage on a step at nanovolt level. A precise estimate of the dependence of the HTS array step width on operating conditions was obtained. Differences were observed with respect to the results provided by the usual, low sensitivity, techniques, confirming that the method we adopted is necessary in the study of HTS arrays for metrology. The high sensitivity analysis was applied in the derivation of the temperature dependence of the critical current as well, providing some insights on the behaviour of the HTS array

  1. Study and operating conditions of HTS Josephson arrays for metrological application

    International Nuclear Information System (INIS)

    Sosso, A.; Lacquaniti, V.; Andreone, D.; Cerri, R.; Klushin, A.M.

    2006-01-01

    We report an experimental study of metrological properties of high-temperature superconductor arrays, made of shunted bicrystal YBCO Josephson junctions. The work is mainly based on a direct comparison against a low temperature array. Owing to the high sensitivity of the measurements, we observed at nanovolt level the changes in the HTS array voltage on a step. A precise estimate of the dependence of the HTS array step width on operating conditions was obtained. Differences were observed with respect to the results of low sensitivity techniques, confirming that our method is necessary in the study of HTS arrays for metrology. The high sensitivity analysis was also applied in the derivation of the temperature dependence of the critical current, providing insights on the behavior of the HTS array

  2. Assessment of the Revised 3410 Building Filtered Exhaust Stack Sampling Probe Location

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Xiao-Ying [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Recknagle, Kurtis P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Glissmeyer, John A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2013-12-01

    . Uniform Concentration of Tracer Gases—The uniformity of the concentration of potential contaminants is first tested using a tracer gas to represent gaseous effluents. The tracer is injected downstream of the fan outlets and at the junction downstream fan discharges meet. The acceptance criteria are that 1) the COV of the measured tracer gas concentration is ≤20% across the center two-thirds of the sampling plane and 2) at no point in the sampling plane does the concentration vary from the mean by >30%. Our test results show that 1) the COV of the measured tracer gas concentration is < 2.9% for all test conditions and 2) at no point in the sampling plane does the concentration vary from the mean by >6.5%. 4. Uniform Concentration of Tracer Particles—Tracer particles of 10-μm aerodynamic diameter are used for the second demonstration of concentration uniformity. The acceptance criterion is that the COV of particle concentration is ≤ 20% across the center two thirds of the sampling plane. Our test results indicate that the COV of particle concentration is <9.9% across the center two-thirds of the sampling plane among all testing conditions. Thus, the reconfigured 3410 Building Filtered Exhaust Stack was determined to meet the qualification criteria given in the ANSI/HPS N13.1-2011 standard. Changes to the system configuration or operations outside the bounds described in this report (e.g., exhaust stack velocity changes, relocation of sampling probe, and addition of fans) may require re-testing or re-evaluation to determine compliance.

  3. Annular feed air breathing fuel cell stack

    Science.gov (United States)

    Wilson, Mahlon S.; Neutzler, Jay K.

    1997-01-01

    A stack of polymer electrolyte fuel cells is formed from a plurality of unit cells where each unit cell includes fuel cell components defining a periphery and distributed along a common axis, where the fuel cell components include a polymer electrolyte membrane, an anode and a cathode contacting opposite sides of the membrane, and fuel and oxygen flow fields contacting the anode and the cathode, respectively, wherein the components define an annular region therethrough along the axis. A fuel distribution manifold within the annular region is connected to deliver fuel to the fuel flow field in each of the unit cells. The fuel distribution manifold is formed from a hydrophilic-like material to redistribute water produced by fuel and oxygen reacting at the cathode. In a particular embodiment, a single bolt through the annular region clamps the unit cells together. In another embodiment, separator plates between individual unit cells have an extended radial dimension to function as cooling fins for maintaining the operating temperature of the fuel cell stack.

  4. Continuous improvement of operation and maintenance conditions of French PWR nuclear islands

    International Nuclear Information System (INIS)

    Bitsch, D.

    1985-01-01

    Improvement of nuclear island design to facilitate maintenance and working conditions during plant shutdown has been a subject of particular attention in the French PWR programme. Standardization and industrial concentration created an unusually favourable situation for approaching this objective. Progress efforts supported by the feedback of actual operating experience were pursued in areas of plant layout equipment installation, and on the design and technology of the components themselves. When compared with units of the three-loop series currently in operation, the evolution of the latest nuclear island designs covers such layout features as better segregation and separation between systems, easier access in special areas, installation of new cleaning systems, etc. Progress efforts on the design and technology of components were pursued along several paths including: (a) the increase in resistance of specific parts submitted to various forms of in-service degradation, for example, steam generator tubes, reactor coolant pump seals, reactor control cluster drive lines and some auxiliary equipment; (b) reduction of the extent and duration of work during plant outages (fuel handling, in-service inspection, maintenance) by facilitating disassembly, removal, handling and storage of equipment parts; (c) reduction of occupational radiation exposure, one of the most important axes of development, by the appropriate selection of less activity-releasing materials such as Inconel 690 for the steam generator tubes, implementation of more efficient decontamination systems and use of robots. (author)

  5. Decision Optimization for Power Grid Operating Conditions with High- and Low-Voltage Parallel Loops

    Directory of Open Access Journals (Sweden)

    Dong Yang

    2017-05-01

    Full Text Available With the development of higher-voltage power grids, the high- and low-voltage parallel loops are emerging, which lead to energy losses and even threaten the security and stability of power systems. The multi-infeed high-voltage direct current (HVDC configurations widely appearing in AC/DC interconnected power systems make this situation even worse. Aimed at energy saving and system security, a decision optimization method for power grid operating conditions with high- and low-voltage parallel loops is proposed in this paper. Firstly, considering hub substation distribution and power grid structure, parallel loop opening schemes are generated with GN (Girvan-Newman algorithms. Then, candidate opening schemes are preliminarily selected from all these generated schemes based on a filtering index. Finally, with the influence on power system security, stability and operation economy in consideration, an evaluation model for candidate opening schemes is founded based on analytic hierarchy process (AHP. And a fuzzy evaluation algorithm is used to find the optimal scheme. Simulation results of a New England 39-bus system and an actual power system validate the effectiveness and superiority of this proposed method.

  6. A study of operational conditions for anaerobic digestion of solid urban waste

    Directory of Open Access Journals (Sweden)

    Édgar Femando Castillo M.

    2003-07-01

    Full Text Available This paper describes an experimental evaluation of anaerobic digestion as a technological option for organic solid-waste treatment in the city of Bucaramanga (Santander, Colombia. The inoculum was selected by evaluating three different anaerobic sludges. Sludge from UASB No. 2 digestor at the Waste Water Treatment Plant in Rio Frío (Girón, Santander was named [PTAR]. Sludge from the anaerobic biodigestor for pig manure treatment (Mesa de Los Santos, Santander was named [PIG] a 1:1 sludge mixture of [PTAR] and [PIG] sludges was named [MIX]. These sludges' methanisation behaviour was evaluated in three different 500 ml capacity CSTR digesters at mesophyllic and thermophyllic temperatures. 25,20 and 18 day retention times were studied in a 20 1 CSTR digester having a 131 reaction volume. The results showed that raising the temperature from 10 °C to 15 °C above normal reactor temperature increased methane production by 3 times. It was also seen that retention time had a strong influence on specific methane production since the best conversions were registered at the longest time recorded (25 days and it had a strong influence on DQO removal too. Another important condition for biodigestor optimal operation was agitation speed;this operation must be semi-continuous for maintaining methanisation process biological activity.

  7. 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.

  8. 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.

  9. Risk assessment during operating self-propelled lifting jib cranes in conditions of insufficient information

    Directory of Open Access Journals (Sweden)

    Lagerev A.V.

    2017-06-01

    Full Text Available Presents the results of statistical analyses identified by the expert diagnostics of defects of the self-propelled lifting jib cranes, spent a normative term of exploitation. The greatest number of defects associated with the destruction and dete-rioration of structural elements, the occurrence of fatigue cracks and a violation of the conditions of operation of the equipment. The greatest number of defects occurs in the hydraulic system of cranes, the rope-block system, and rarely in steel structures. To conduct risk analysis of self-propelled jib cranes in case of insufficient information, proposed the method of expert estimations. It allows to assess the impact of potential defects on self-propelled jib cranes on the value of the economic damage of the crane and moving cargo and the value of the traumatic exposure on men. The proposed list of possible defects self-propelled lifting jib cranes and a checklist of questions about the degree of influence of these defects. Proposed calculated dependences to the approximate calculation of the magnitude of technical risk in the opera-tion of self-propelled jib cranes. The results of statistical analysis of expert estimations for each possible defect and per-formed their ranking in terms of impact on the magnitude of the economic damage of the crane and moving loads, the value of the traumatic exposure. Was calculated the value of technical risk for the surveyed taps.

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

    Science.gov (United States)

    Osterhagen, Lasse; Breteler, Marinus; van Luijtelaar, Gilles

    2010-06-01

    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 training on seizure occurrence have been described in epileptic patients. Little research has been done about differentiating NF effectiveness by type of epilepsy, particularly, whether idiopathic generalized seizures are susceptible to NF. In this experiment, seizures that manifest themselves as spike-wave discharges (SWDs) in the EEG were reinforced during 10 sessions in 6 rats of the WAG/Rij strain, an animal model for absence epilepsy. EEG's were recorded before and after the training sessions. Reinforcing SWDs let to decreased SWD occurrences during training; however, the changes during training were not persistent in the post-training sessions. Because behavioural states are known to have an influence on the occurrence of SWDs, it is proposed that the reinforcement situation increased arousal which resulted in fewer SWDs. Additional tests supported this hypothesis. The outcomes have implications for the possibility to train SWDs with operant learning techniques. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  11. Scenario based optimization of a container vessel with respect to its projected operating conditions

    Directory of Open Access Journals (Sweden)

    Wagner Jonas

    2014-06-01

    Full Text Available In this paper the scenario based optimization of the bulbous bow of the KRISO Container Ship (KCS is presented. The optimization of the parametrically modeled vessel is based on a statistically developed operational profile generated from noon-to-noon reports of a comparable 3600 TEU container vessel and specific development functions representing the growth of global economy during the vessels service time. In order to consider uncertainties, statistical fluctuations are added. An analysis of these data lead to a number of most probable upcoming operating conditions (OC the vessel will stay in the future. According to their respective likeliness an objective function for the evaluation of the optimal design variant of the vessel is derived and implemented within the parametrical optimization workbench FRIENDSHIP Framework. In the following this evaluation is done with respect to vessel’s calculated effective power based on the usage of potential flow code. The evaluation shows, that the usage of scenarios within the optimization process has a strong influence on the hull form.

  12. Scenario based optimization of a container vessel with respect to its projected operating conditions

    Directory of Open Access Journals (Sweden)

    Jonas Wagner

    2014-06-01

    Full Text Available In this paper the scenario based optimization of the bulbous bow of the KRISO Container Ship (KCS is presented. The optimization of the parametrically modeled vessel is based on a statistically developed operational profile generated from noon-to-noon reports of a comparable 3600 TEU container vessel and specific development functions representing the growth of global economy during the vessels service time. In order to consider uncertainties, statistical fluctuations are added. An analysis of these data lead to a number of most probable upcoming operating conditions (OC the vessel will stay in the future. According to their respective likeliness an objective function for the evaluation of the optimal design variant of the vessel is derived and implemented within the parametrical optimization workbench FRIENDSHIP Framework. In the following this evaluation is done with respect to vessel's calculated effective power based on the usage of potential flow code. The evaluation shows, that the usage of scenarios within the optimization process has a strong influence on the hull form.

  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. Development and Applications of a Stage Stacking Procedure

    Science.gov (United States)

    Kulkarni, Sameer; Celestina, Mark L.; Adamczyk, John J.

    2012-01-01

    The preliminary design of multistage axial compressors in gas turbine engines is typically accomplished with mean-line methods. These methods, which rely on empirical correlations, estimate compressor performance well near the design point, but may become less reliable off-design. For land-based applications of gas turbine engines, off-design performance estimates are becoming increasingly important, as turbine plant operators desire peaking or load-following capabilities and hot-day operability. The current work develops a one-dimensional stage stacking procedure, including a newly defined blockage term, which is used to estimate the off-design performance and operability range of a 13-stage axial compressor used in a power generating gas turbine engine. The new blockage term is defined to give mathematical closure on static pressure, and values of blockage are shown to collapse to curves as a function of stage inlet flow coefficient and corrected shaft speed. In addition to these blockage curves, the stage stacking procedure utilizes stage characteristics of ideal work coefficient and adiabatic efficiency. These curves are constructed using flow information extracted from computational fluid dynamics (CFD) simulations of groups of stages within the compressor. Performance estimates resulting from the stage stacking procedure are shown to match the results of CFD simulations of the entire compressor to within 1.6% in overall total pressure ratio and within 0.3 points in overall adiabatic efficiency. Utility of the stage stacking procedure is demonstrated by estimation of the minimum corrected speed which allows stable operation of the compressor. Further utility of the stage stacking procedure is demonstrated with a bleed sensitivity study, which estimates a bleed schedule to expand the compressors operating range.

  15. Multipole Stack for the 800 MeV PS Booster

    CERN Multimedia

    1975-01-01

    The 800 MeV PS Booster had seen first beam in its 4 superposed rings in 1972, routine operation began in 1973. In the strive for ever higher beam intensities, the need for additional multipole lenses became evident. After detailed studies, the manufacture of 8 stacks of multipoles was launched in 1974. Each stack consists of 4 superposed multipoles and each multipole has 4 concentric shells. From the innermost to the outermost shell, Type A contains octupole, skew-octupole, sextupole, skew-sextupole. Type B contains skew-octupole, skew-sextupole, vertical dipole, horizontal dipole. Completion of installation in 1976 opened the way to higher beam intensities. M. Battiaz is seen here with a multipole stack and its many electrical connections.

  16. Optimization of the operational conditions of a multichannel analyzer gamma spectrometer

    International Nuclear Information System (INIS)

    Mosse, H.

    1974-01-01

    For the optimization of the operational conditions of a multichannel analyser gamma spectrometer, with two 3'' x 3'' NaI (Tl) crystals in opposition, several parameters were studied, which are responsable for the best counting efficiency, in each type of sample to be analysed. Thus, electronic conditions, shielding, sample holding, resolution, geometry (or the sample positioning between the detectors), were investigated. Self-absorption, sample density and the effects of the shape of the containers were also tested. For solid samples, (usually ashed), the best container was found to be a plastic cylinder, with the sample pressed inside. For liquid samples, plastic cylindric flasks were also found to be the best ones. Environmental samples were measured with internal standards for 137 Cs and 40 K. Results were compared with those obtained by physical (atomic adsorption for K) and radiochemical methods (Cs precipitation by amonium phosphomolibdate). Results show good agreement with the spectrometric analysis. For comparison with environmental samples, standards were prepared, in such a way that they could simulated their physical caracteristics. The minimum detectable activity was determined for 137 Cs. Results show values of 0.01 pCi/g for the 1 Kg samples, and 0.004 pCi/g for the 300g ones. By the measurement of 40 K, we found this value to be 0.02 mgK/g, in both cases. (author) [pt

  17. 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.

  18. Laccase-HBT bleaching of eucalyptus kraft pulp: influence of the operating conditions.

    Science.gov (United States)

    Moldes, D; Vidal, T

    2008-12-01

    Different operating conditions (viz. pulp consistency, oxygen pressure and treatment time) in the biobleaching of eucalyptus kraft pulp with the laccase-HBT system was tested in order to describe their effect and normalize a biobleaching protocol. A high O(2) pressure (0.6MPa) was found to result in improved laccase-assisted delignification of the pulp. Also, a high pulp consistency (10%) and a short treatment time (2h) proved the best choices with a view to obtaining good pulp properties (kappa number and ISO brightness) under essentially mild conditions. The laccase-HBT treatment was found to result in slight delignification (in the form of a 20-27% decrease in kappa number); however, an alkaline extraction stage raised delignification to 41-45%, a much higher level than those obtained in the control tests (16-23%). Also, the use of hydrogen peroxide in the extraction stage resulted in improved brightness (14-19%), but in scarcely improved delignification (4-7%). Treating the pulp with the laccase-HBT system reduced the amount of hydrogen peroxide required for subsequent alkaline bleaching by a factor of 3-4 relative to control tests.

  19. Development of Future Rule Curves for Multipurpose Reservoir Operation Using Conditional Genetic and Tabu Search Algorithms

    Directory of Open Access Journals (Sweden)

    Anongrit Kangrang

    2018-01-01

    Full Text Available Optimal rule curves are necessary guidelines in the reservoir operation that have been used to assess performance of any reservoir to satisfy water supply, irrigation, industrial, hydropower, and environmental conservation requirements. This study applied the conditional genetic algorithm (CGA and the conditional tabu search algorithm (CTSA technique to connect with the reservoir simulation model in order to search optimal reservoir rule curves. The Ubolrat Reservoir located in the northeast region of Thailand was an illustrative application including historic monthly inflow, future inflow generated by the SWAT hydrological model using 50-year future climate data from the PRECIS regional climate model in case of B2 emission scenario by IPCC SRES, water demand, hydrologic data, and physical reservoir data. The future and synthetic inflow data of reservoirs were used to simulate reservoir system for evaluating water situation. The situations of water shortage and excess water were shown in terms of frequency magnitude and duration. The results have shown that the optimal rule curves from CGA and CTSA connected with the simulation model can mitigate drought and flood situations than the existing rule curves. The optimal future rule curves were more suitable for future situations than the other rule curves.

  20. 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.

  1. Effect of Alcohol on Diesel Engine Combustion Operating with Biodiesel-Diesel Blend at Idling Conditions

    Science.gov (United States)

    Mahmudul, H. M.; Hagos, Ftwi. Y.; A, M. Mukhtar N.; Mamat, Rizalman; Abdullah, A. Adam

    2018-03-01

    Biodiesel is a promising alternative fuel to run the automotive engine. However, its blends have not been properly investigated during idling as it is the main problem to run the vehicles in a big city. The purpose of this study is to evaluate the impact of alcohol additives such as butanol and ethanol on combustion parameters under idling conditions when a single cylinder diesel engine operates with diesel, diesel-biodiesel blends, and diesel biodiesel-alcohol blends. The engine combustion parameters such as peak pressure, heat release rate and ignition delay were computed. This investigation has revealed that alcohol blends with diesel and biodiesel, BU20 blend yield higher maximum peak cylinder pressure than diesel. B5 blend was found with the lowest energy release among all. B20 was slightly lower than diesel. BU20 blend was seen with the highest peak energy release where E20 blend was found advance than diesel. Among all, the blends alcohol component revealed shorter ignition delay. B5 and B20 blends were influenced by biodiesel interference and the burning fraction were found slightly slower than conventional diesel where BU20 and E20 blends was found slightly faster than diesel So, based on the result, it can be said that among the alcohol blends butanol and ethanol can be promising alternative at idling conditions and can be used without any engine modifications.

  2. Reconstruction of baseline time-trace under changing environmental and operational conditions

    International Nuclear Information System (INIS)

    Aryan, P; Kotousov, A; Ng, C T; Wildy, S

    2016-01-01

    Compensation of changing environmental and operational conditions (EOC) is often necessary when using guided-wave based techniques for structural health monitoring in real-world applications. Many studies have demonstrated that the effect of changing EOC can mask damage to a degree that a critical defect might not be detected. Several effective strategies, specifically for compensating the temperature variations, have been developed in recent years. However, many other factors, such as changing humidity and boundary conditions or degradation of material properties, have not received much attention. This paper describes a practical method for reconstruction of the baseline time-trace corresponding to the current EOC. Thus, there is no need for differentiation or compensation procedures when using this method for damage diagnosis. It is based on 3D surface measurements of the velocity field near the actuator using laser vibrometry, in conjunction with high-fidelity finite element simulations of guided wave propagation in free from defects structure. To demonstrate the feasibility and efficiency of the proposed method we provide several examples of the reconstruction and damage detection. (paper)

  3. Reconstruction of baseline time-trace under changing environmental and operational conditions

    Science.gov (United States)

    Aryan, P.; Kotousov, A.; Ng, C. T.; Wildy, S.

    2016-03-01

    Compensation of changing environmental and operational conditions (EOC) is often necessary when using guided-wave based techniques for structural health monitoring in real-world applications. Many studies have demonstrated that the effect of changing EOC can mask damage to a degree that a critical defect might not be detected. Several effective strategies, specifically for compensating the temperature variations, have been developed in recent years. However, many other factors, such as changing humidity and boundary conditions or degradation of material properties, have not received much attention. This paper describes a practical method for reconstruction of the baseline time-trace corresponding to the current EOC. Thus, there is no need for differentiation or compensation procedures when using this method for damage diagnosis. It is based on 3D surface measurements of the velocity field near the actuator using laser vibrometry, in conjunction with high-fidelity finite element simulations of guided wave propagation in free from defects structure. To demonstrate the feasibility and efficiency of the proposed method we provide several examples of the reconstruction and damage detection.

  4. 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.

  5. Learning-dependent plasticity in human auditory cortex during appetitive operant conditioning.

    Science.gov (United States)

    Puschmann, Sebastian; Brechmann, André; Thiel, Christiane M

    2013-11-01

    Animal experiments provide evidence that learning to associate an auditory stimulus with a reward causes representational changes in auditory cortex. However, most studies did not investigate the temporal formation of learning-dependent plasticity during the task but rather compared auditory cortex receptive fields before and after conditioning. We here present a functional magnetic resonance imaging study on learning-related plasticity in the human auditory cortex during operant appetitive conditioning. Participants had to learn to associate a specific category of frequency-modulated tones with a reward. Only participants who learned this association developed learning-dependent plasticity in left auditory cortex over the course of the experiment. No differential responses to reward predicting and nonreward predicting tones were found in auditory cortex in nonlearners. In addition, learners showed similar learning-induced differential responses to reward-predicting and nonreward-predicting tones in the ventral tegmental area and the nucleus accumbens, two core regions of the dopaminergic neurotransmitter system. This may indicate a dopaminergic influence on the formation of learning-dependent plasticity in auditory cortex, as it has been suggested by previous animal studies. Copyright © 2012 Wiley Periodicals, Inc.

  6. ''Meteor 2'' programme for calculation of environment irradiation under nuclear power plant normal operating conditions

    International Nuclear Information System (INIS)

    Oppermann, R.; Kryuger, F.V.; Prior, Kh.

    1976-01-01

    A ''Meteor 2'' program developed for the BESM-6 electronic computer is described. The program permits to estimate radiation effect under nuclear power plant normal operation conditions. The calculations are carried out depending on the quantity and composition of the release activity, a ventilating pipe height, meteorological conditions as well as taking into account radioactive substance decay. The program permits to calculate the following values in the vicinity of radioactive product release point: a local distribution of a mean dose spread factor; a local distribution of a mean dose of inhalation irradiation for various human organs (the whole body, thyroid gland, bones, alimentary canal, lungs) and separate population groups; a local distribution of a mean dose of external beta radiation; a local distribution of a mean dose of external gamma radiation. The program includes the main ''Meteor'' program and 3 subprograms of DOBER, DABER and DABOR and is written in the FORTRAN language. The ''Meteor'' program organizes the data input and output of some separate subprograms. The DOBER subprogram determines the spread factor, the inhalation irradiation dose for separate organs and the external beta radiation dose. The DABER subprogram determines the external gamma radiation dose in the approximation of homogeneous distribution of a source in the vicinity of the calculation point. The DABOR subprogram is the second program for the calculating the external irradiation dose. The examples of using the ''Meteor'' program are given [ru

  7. Evaluation of gap heat transfer model in ELESTRES for CANDU fuel element under normal operating conditions

    International Nuclear Information System (INIS)

    Lee, Kang Moon; Ohn, Myung Ryong; Im, Hong Sik; Choi, Jong Hoh; Hwang, Soon Taek

    1995-01-01

    The gap conductance between the fuel and the sheath depends strongly on the gap width and has a significant influence on the amount of initial stored energy. The modified Ross and Stoute gap conductance model in ELESTRES is based on a simplified thermal deformation model for steady-state fuel temperature calculations. A review on a series of experiments reveals that fuel pellets crack, relocate, and are eccentrically positioned within the sheath rather than solid concentric cylinders. In this paper, the two recently-proposed gap conductance models (offset gap model and relocated gap model) are described and are applied to calculate the fuel-sheath gap conductances under experimental conditions and normal operating conditions in CANDU reactors. The good agreement between the experimentally-inferred and calculated gap conductance values demonstrates that the modified Ross and Stoute model was implemented correctly in ELESTRES. The predictions of the modified Ross and Stoute model provide conservative values for gap heat transfer and fuel surface temperature compared to the offset gap and relocated gap models for a limiting power envelope. 13 figs., 3 tabs., 16 refs. (Author)

  8. Generalized diffraction-stack migration and filtering of coherent noise

    KAUST Repository

    Zhan, Ge

    2014-01-27

    We reformulate the equation of reverse-time migration so that it can be interpreted as summing data along a series of hyperbola-like curves, each one representing a different type of event such as a reflection or multiple. This is a generalization of the familiar diffraction-stack migration algorithm where the migration image at a point is computed by the sum of trace amplitudes along an appropriate hyperbola-like curve. Instead of summing along the curve associated with the primary reflection, the sum is over all scattering events and so this method is named generalized diffraction-stack migration. This formulation leads to filters that can be applied to the generalized diffraction-stack migration operator to mitigate coherent migration artefacts due to, e.g., crosstalk and aliasing. Results with both synthetic and field data show that generalized diffraction-stack migration images have fewer artefacts than those computed by the standard reverse-time migration algorithm. The main drawback is that generalized diffraction-stack migration is much more memory intensive and I/O limited than the standard reverse-time migration method. © 2014 European Association of Geoscientists & Engineers.

  9. Early detection of power system disturbances as a condition for safe operation of the Dukovany NPP in the 'Island operation mode'

    International Nuclear Information System (INIS)

    Petruzela, I.

    1997-01-01

    The ''Frequency Plan'' worked out for the Czech Power System specifies a set of preventive measures along with the set of the frequency ranges. This problem was solved in details for the Dukovany nuclear power plant. The design changes under preparation support a reliable as well as safe operation in the island-operation mode until a full restoration of the whole power system. The design modifications are based on the following three main innovations: An incorporation of the FREA 16 frequency relay into the protection circuits; large modifications in turbine control loops; installation of software routine for the operator to support the island operation mode. The capability of the island operation has been demanded by relevant regulations both for the operating units and for that under construction. The capability can be tested under the transition to houseloads, as well as through the direct simulation of abnormal grid conditions. 1 fig

  10. Long term performance degradation analysis and optimization of anode supported solid oxide fuel cell stacks

    International Nuclear Information System (INIS)

    Parhizkar, Tarannom; Roshandel, Ramin

    2017-01-01

    Highlights: • A degradation based optimization framework is developed. • The cost of electricity based on degradation of solid oxide fuel cells is minimized. • The effects of operating conditions on degradation mechanisms are investigated. • Results show 7.12% lower cost of electricity in comparison with base case. • Degradation based optimization is a beneficial concept for long term analysis. - Abstract: The main objective of this work is minimizing the cost of electricity of solid oxide fuel cell stacks by decelerating degradation mechanisms rate in long term operation for stationary power generation applications. The degradation mechanisms in solid oxide fuel cells are caused by microstructural changes, reactions between lanthanum strontium manganite and electrolyte, poisoning by chromium, carburization on nickel particles, formation of nickel sulfide, nickel coarsening, nickel oxidation, loss of conductivity and crack formation in the electrolyte. The rate of degradation mechanisms depends on the cell operating conditions (cell voltage and fuel utilization). In this study, the degradation based optimization framework is developed which determines optimum operating conditions to achieve a minimum cost of electricity. To show the effectiveness of the developed framework, optimization results are compared with the case that system operates at its design point. Results illustrate optimum operating conditions decrease the cost of electricity by 7.12%. The performed study indicates that degradation based optimization is a beneficial concept for long term performance degradation analysis of energy conversion systems.

  11. 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

  12. 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

  13. Remaining useful life estimation in heterogeneous fleets working under variable operating conditions

    International Nuclear Information System (INIS)

    Al-Dahidi, Sameer; Di Maio, Francesco; Baraldi, Piero; Zio, Enrico

    2016-01-01

    The availability of condition monitoring data for large fleets of similar equipment motivates the development of data-driven prognostic approaches that capitalize on the information contained in such data to estimate equipment Remaining Useful Life (RUL). A main difficulty is that the fleet of equipment typically experiences different operating conditions, which influence both the condition monitoring data and the degradation processes that physically determine the RUL. We propose an approach for RUL estimation from heterogeneous fleet data based on three phases: firstly, the degradation levels (states) of an homogeneous discrete-time finite-state semi-markov model are identified by resorting to an unsupervised ensemble clustering approach. Then, the parameters of the discrete Weibull distributions describing the transitions among the states and their uncertainties are inferred by resorting to the Maximum Likelihood Estimation (MLE) method and to the Fisher Information Matrix (FIM), respectively. Finally, the inferred degradation model is used to estimate the RUL of fleet equipment by direct Monte Carlo (MC) simulation. The proposed approach is applied to two case studies regarding heterogeneous fleets of aluminium electrolytic capacitors and turbofan engines. Results show the effectiveness of the proposed approach in predicting the RUL and its superiority compared to a fuzzy similarity-based approach of literature. - Highlights: • The prediction of the remaining useful life for heterogeneous fleets is addressed. • A data-driven prognostics approach based on a Markov model is proposed. • The proposed approach is applied to two different heterogeneous fleets. • The results are compared with those obtained by a fuzzy similarity-based approach.

  14. 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.)

  15. Computerized plutonium laboratory-stack monitoring system

    International Nuclear Information System (INIS)

    Stafford, R.G.; DeVore, R.K.

    1977-01-01

    The Los Alamos Scientific Laboratory has recently designed and constructed a Plutonium Research and Development Facility to meet design criteria imposed by the United States Energy Research and Development Administration. A primary objective of the design criteria is to assure environmental protection and to reliably monitor plutonium effluent via the ventilation exhaust systems. A state-of-the-art facility exhaust air monitoring system is described which establishes near ideal conditions for evaluating plutonium activity in the stack effluent. Total and static pressure sensing manifolds are incorporated to measure average velocity and integrated total discharge air volume. These data are logged at a computer which receives instrument data through a multiplex scanning system. A multipoint isokinetic sampling assembly with associated instrumentation is described. Continuous air monitors have been designed to sample from the isokinetic sampling assembly and transmit both instantaneous and integrated stack effluent concentration data to the computer and various cathode ray tube displays. The continuous air monitors also serve as room air monitors in the plutonium facility with the primary objective of timely evacuation of personnel if an above tolerance airborne plutonium concentration is detected. Several continuous air monitors are incorporated in the ventilation system to assist in identification of release problem areas

  16. A phase angle based diagnostic scheme to planetary gear faults diagnostics under non-stationary operational conditions

    Science.gov (United States)

    Feng, Ke; Wang, Kesheng; Ni, Qing; Zuo, Ming J.; Wei, Dongdong

    2017-11-01

    Planetary gearbox is a critical component for rotating machinery. It is widely used in wind turbines, aerospace and transmission systems in heavy industry. Thus, it is important to monitor planetary gearboxes, especially for fault diagnostics, during its operational conditions. However, in practice, operational conditions of planetary gearbox are often characterized by variations of rotational speeds and loads, which may bring difficulties for fault diagnosis through the measured vibrations. In this paper, phase angle data extracted from measured planetary gearbox vibrations is used for fault detection under non-stationary operational conditions. Together with sample entropy, fault diagnosis on planetary gearbox is implemented. The proposed scheme is explained and demonstrated in both simulation and experimental studies. The scheme proves to be effective and features advantages on fault diagnosis of planetary gearboxes under non-stationary operational conditions.

  17. 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

  18. Compactifications of reductive groups as moduli stacks of bundles

    DEFF Research Database (Denmark)

    Martens, Johan; Thaddeus, Michael

    Let G be a reductive group. We introduce the moduli problem of "bundle chains" parametrizing framed principal G-bundles on chains of lines. Any fan supported in a Weyl chamber determines a stability condition on bundle chains. Its moduli stack provides an equivariant toroidal compactification of G...

  19. Lightweight Stacks of Direct Methanol Fuel Cells

    Science.gov (United States)

    Narayanan, Sekharipuram; Valdez, Thomas

    2004-01-01

    An improved design concept for direct methanol fuel cells makes it possible to construct fuel-cell stacks that can weigh as little as one-third as much as do conventional bipolar fuel-cell stacks of equal power. The structural-support components of the improved cells and stacks can be made of relatively inexpensive plastics. Moreover, in comparison with conventional bipolar fuel-cell stacks, the improved fuel-cell stacks can be assembled, disassembled, and diagnosed for malfunctions more easily. These improvements are expected to bring portable direct methanol fuel cells and stacks closer to commercialization. In a conventional bipolar fuel-cell stack, the cells are interspersed with bipolar plates (also called biplates), which are structural components that serve to interconnect the cells and distribute the reactants (methanol and air). The cells and biplates are sandwiched between metal end plates. Usually, the stack is held together under pressure by tie rods that clamp the end plates. The bipolar stack configuration offers the advantage of very low internal electrical resistance. However, when the power output of a stack is only a few watts, the very low internal resistance of a bipolar stack is not absolutely necessary for keeping the internal power loss acceptably low.

  20. A combination of Dirichlet to Neumann operators and perfectly matched layers as boundary conditions for optical finite element simulations

    NARCIS (Netherlands)

    Stoffer, Remco; Sopaheluwakan, A.; Hammer, Manfred; van Groesen, Embrecht W.C.

    2008-01-01

    By combining Dirichlet to Neumann (DtN) operators and Perfectly Matched Layers (PML’s) as boundary conditions on a rectangular domain on which the Helmholtz equation is solved, the disadvantages of both methods are greatly diminished. Due to the DtN operators, light may be accurately fluxed into the

  1. Electric toy vehicle powered by a PEMFC stack

    Energy Technology Data Exchange (ETDEWEB)

    Beneito, Ruben; Vilaplana, Joaquin; Gisbert, Santiago [Technological Institute for Toy (AIJU), 03440 Ibi (Spain)

    2007-07-15

    The article describes the design and development of an electric toy vehicle powered by a fuel cell stack. The system consisted of a 150 W PEMFC stack powered by hydrogen/air, a tank of metal hydrides of AB (TiFe) alloy type with a capacity of 300 standard litres, for storing hydrogen, and an electronic power device based on electrolytic capacitors, to supply peak power demands during acceleration and start up of the vehicle. The air supply was provided by a fan preceded by a filter, and in a similar manner the stack was cooled by an air ventilation system. An electrovalve was used to supply H{sub 2} in dead-ended mode. All the components were integrated in the vehicle, and the prototype was tested in real working conditions, in a test bench and by children. (author)

  2. Stacking and discontinuous buffers in capillary zone electrophoresis.

    Science.gov (United States)

    Shihabi, Z K

    2000-08-01

    Discontinuous buffers for capillary zone electrophoresis (CZE) can be used under less rigid conditions compared to those for isotachophoresis for stacking. They can be prepared simply by modifying the sample itself, either by addition of small inorganic ions, low conductivity diluents, or both, and also by adjusting its pH, meanwhile injecting a large volume on the capillary. Zwitterionic and organic-based buffers such as triethanolamine and tris(hydroxymethyl)aminomethane (Tris) are well suited for stacking due to their low conductivity, provided the buffer is discontinuous as demonstrated here. A simple mechanism based on discontinuous buffers is described to explain many of the observed stacking types in CZE, pointing out the many similarities to transient isotachophoresis.

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

    Directory of Open Access Journals (Sweden)

    I. A. Elzein

    2017-01-01

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

  4. Automated ambulatory assessment of cognitive performance, environmental conditions, and motor activity during military operations

    Science.gov (United States)

    Lieberman, Harris R.; Kramer, F. Matthew; Montain, Scott J.; Niro, Philip; Young, Andrew J.

    2005-05-01

    Until recently scientists had limited opportunities to study human cognitive performance in non-laboratory, fully ambulatory situations. Recently, advances in technology have made it possible to extend behavioral assessment to the field environment. One of the first devices to measure human behavior in the field was the wrist-worn actigraph. This device, now widely employed, can acquire minute-by-minute information on an individual"s level of motor activity. Actigraphs can, with reasonable accuracy, distinguish sleep from waking, the most critical and basic aspect of human behavior. However, rapid technologic advances have provided the opportunity to collect much more information from fully ambulatory humans. Our laboratory has developed a series of wrist-worn devices, which are not much larger then a watch, which can assess simple and choice reaction time, vigilance and memory. In addition, the devices can concurrently assess motor activity with much greater temporal resolution then the standard actigraph. Furthermore, they continuously monitor multiple environmental variables including temperature, humidity, sound and light. We have employed these monitors during training and simulated military operations to collect information that would typically be unavailable under such circumstances. In this paper we will describe various versions of the vigilance monitor and how each successive version extended the capabilities of the device. Samples of data from several studies are presented, included studies conducted in harsh field environments during simulated infantry assaults, a Marine Corps Officer training course and mechanized infantry (Stryker) operations. The monitors have been useful for documenting environmental conditions experienced by wearers, studying patterns of sleep and activity and examining the effects of nutritional manipulations on warfighter performance.

  5. 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.

  6. SOLAR SYSTEMS FOR RESIDENTIAL BUILDINGS IN ACCORDANCE WITH OPERATING CONDITIONS OF THE REPUBLIC OF BELARUS

    Directory of Open Access Journals (Sweden)

    M. A. Rutkowski

    2017-01-01

    Full Text Available Solar systems are actively applied for heat supply of buildings in Europe. Usage of solar energy for heat supply of residential buildings is considered as rather efficient for the Republic of Belarus because total amount of direct and scattered solar radiation entering horizontal surface is equivalent to an average European index for the climate of Belarus. The paper analyzes an existing dependence on determination of solar system efficiency and proposes an amended formula for calculations while designing solar consumption systems and its legitimacy has been experimentally proved. A scheme of an experimental unit with explanations and a brief description for execution of experiments and main results of the completed investigations have been presented in the paper. Experiments have been carried out for solar systems with natural and forced coolant circulation. Attention has been paid to obtaining maximum possible temperature potential of the coolant during operation of the solar system within periods of high and low solar radiation intensity. Recommendations on practical application of solar systems for multi-storey residential buildings houses and mansion-type houses have been given in the paper. The paper presents technological principles of constructing “passive” solar heating devices. A comparison of traditionally applied and proposed alternative solar systems has been made for operational conditions in Belarus. The paper proposes a solar system for hot water supply of multi-storey buildings. The proposed system has found its first realization in the Republic while designing and constructing an energy-efficient demonstration 10-storey residential building in Mogilev within the framework of the UN Development Program project and Global Environment Fund “Improvement of energy efficiency for residential buildings in the Republic of Belarus”

  7. ATLAS software stack on ARM64

    Science.gov (United States)

    Smith, Joshua Wyatt; Stewart, Graeme A.; Seuster, Rolf; Quadt, Arnulf; ATLAS Collaboration

    2017-10-01

    This paper reports on the port of the ATLAS software stack onto new prototype ARM64 servers. This included building the “external” packages that the ATLAS software relies on. Patches were needed to introduce this new architecture into the build as well as patches that correct for platform specific code that caused failures on non-x86 architectures. These patches were applied such that porting to further platforms will need no or only very little adjustments. A few additional modifications were needed to account for the different operating system, Ubuntu instead of Scientific Linux 6 / CentOS7. Selected results from the validation of the physics outputs on these ARM 64-bit servers will be shown. CPU, memory and IO intensive benchmarks using ATLAS specific environment and infrastructure have been performed, with a particular emphasis on the performance vs. energy consumption.

  8. ATLAS software stack on ARM64

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00529764; The ATLAS collaboration; Stewart, Graeme; Seuster, Rolf; Quadt, Arnulf

    2017-01-01

    This paper reports on the port of the ATLAS software stack onto new prototype ARM64 servers. This included building the “external” packages that the ATLAS software relies on. Patches were needed to introduce this new architecture into the build as well as patches that correct for platform specific code that caused failures on non-x86 architectures. These patches were applied such that porting to further platforms will need no or only very little adjustments. A few additional modifications were needed to account for the different operating system, Ubuntu instead of Scientific Linux 6 / CentOS7. Selected results from the validation of the physics outputs on these ARM 64-bit servers will be shown. CPU, memory and IO intensive benchmarks using ATLAS specific environment and infrastructure have been performed, with a particular emphasis on the performance vs. energy consumption.

  9. Stacked generalization: an introduction to super learning.

    Science.gov (United States)

    Naimi, Ashley I; Balzer, Laura B

    2018-04-10

    Stacked generalization is an ensemble method that allows researchers to combine several different prediction algorithms into one. Since its introduction in the early 1990s, the method has evolved several times into a host of methods among which is the "Super Learner". Super Learner uses V-fold cross-validation to build the optimal weighted combination of predictions from a library of candidate algorithms. Optimality is defined by a user-specified objective function, such as minimizing mean squared error or maximizing the area under the receiver operating characteristic curve. Although relatively simple in nature, use of Super Learner by epidemiologists has been hampered by limitations in understanding conceptual and technical details. We work step-by-step through two examples to illustrate concepts and address common concerns.

  10. Efficient modeling of metallic interconnects for thermo-mechanical simulation of SOFC stacks: homogenized behaviors and effect of contact

    DEFF Research Database (Denmark)

    Tadesse Molla, Tesfaye; Kwok, Kawai; Frandsen, Henrik Lund

    2016-01-01

    Currently thermo-mechanical analysis of the entire solid oxide fuel cell (SOFC) stack at operational conditions is computationally challenging if the geometry of metallic interconnects is considered explicitly. This is particularly the case when creep deformations in the interconnect are considered...... interconnect. Finally, the developed constitutive law is verified by comparing its predictions for creep strain with results from the original 2D finite element model for different loading conditions. The constitutive law is found to satisfactorily describe the mechanical behavior of corrugated metallic...

  11. Solar-assisted absorption air-conditioning systems in buildings: Control strategies and operational modes

    International Nuclear Information System (INIS)

    Shirazi, Ali; Pintaldi, Sergio; White, Stephen D.; Morrison, Graham L.; Rosengarten, Gary; Taylor, Robert A.

    2016-01-01

    Highlights: • A simulation model of a solar driven absorption chiller is developed in detail. • Three control strategies were proposed in the solar loop of the plant. • Series and parallel auxiliary heater arrangements were investigated. • The results showed the auxiliary-heater in parallel outperformed the series one. • Solar fraction can be increased by 20% by implementing the proposed configuration. - Abstract: Solar-assisted cooling technology has enormous potential for air-conditioning applications since both solar energy supply and cooling energy demand are well correlated. Unfortunately, market uptake of solar cooling technologies has been slow due to the high capital cost and limited design/operational experience. In the present work, different designs and operational modes for solar heating and cooling (SHC) absorption chiller systems are investigated and compared in order to identify the preferred design strategies for these systems. Three control scenarios are proposed for the solar collector loop. The first uses a constant flow pump, while the second and third control schemes employ a variable speed pump, where the solar collector (SC) set-point temperature could be either fixed or adjusted to the required demand. Series and parallel arrangements, between the auxiliary heater and the storage tank, have been examined in detail from an energy efficiency perspective. A simulation model for different system layouts is developed in the transient system simulation environment (TRNSYS, Version 17). Simulation results revealed that the total solar fraction of the plant is increased by up to 11% when a variable speed solar loop pump is used to achieve a collector set-point temperature adjusted according to the building load demand. Another significant finding of this study is that a parallel configuration for the auxiliary heater out-performs a conventional series configuration. The yearly performance of an auxiliary heater in parallel with the storage

  12. Stack Parameters Effect on the Performance of Anharmonic Resonator Thermoacoustic Heat Engine

    KAUST Repository

    Nouh, Mostafa A.

    2014-01-01

    A thermoacoustic heat engine (TAHE) converts heat into acoustic power with no moving parts. It exhibits several advantages over traditional engines, such as simple design, stable functionality, and environment-friendly working gas. In order to further improve the performance of TAHE, stack parameters need to be optimized. Stack\\'s position, length and plate spacing are the three main parameters that have been investigated in this study. Stack\\'s position dictates both the efficiency and the maximum produced acoustic power of the heat engine. Positioning the stack closer to the pressure anti-node might ensure high efficiency on the expense of the maximum produced acoustic power. It is noticed that the TAHE efficiency can further be improved by spacing the plates of the stack at a value of 2.4 of the thermal penetration depth, δk . Changes in the stack length will not affect the efficiency much as long as the temperature gradient across the stack, as a ratio of the critical temperature gradient ψ is more than 1. Upon interpreting the effect of these variations, attempts are made towards reaching the engine\\'s most powerful operating point.

  13. Actuators Using Piezoelectric Stacks and Displacement Enhancers

    Science.gov (United States)

    Bar-Cohen, Yoseph; Sherrit, Stewart; Bao, Xiaoqi; Badescu, Mircea; Lee, Hyeong Jae; Walkenmeyer, Phillip; Lih, Shyh-Shiuh

    2015-01-01

    Actuators are used to drive all active mechanisms including machines, robots, and manipulators to name a few. The actuators are responsible for moving, manipulating, displacing, pushing and executing any action that is needed by the mechanism. There are many types and principles of actuation that are responsible for these movements ranging from electromagnetic, electroactive, thermo-mechanic, piezoelectric, electrostrictive etc. Actuators are readily available from commercial producers but there is a great need for reducing their size, increasing their efficiency and reducing their weight. Studies at JPL’s Non Destructive Evaluation and Advanced Actuators (NDEAA) Laboratory have been focused on the use of piezoelectric stacks and novel designs taking advantage of piezoelectric’s potential to provide high torque/force density actuation and high electromechanical conversion efficiency. The actuators/motors that have been developed and reviewed in this paper are operated by various horn configurations as well as the use of pre-stress flexures that make them thermally stable and increases their coupling efficiency. The use of monolithic designs that pre-stress the piezoelectric stack eliminates the use of compression stress bolt. These designs enable the embedding of developed solid-state motors/actuators in any structure with the only macroscopically moving parts are the rotor or the linear translator. Finite element modeling and design tools were used to determine the requirements and operation parameters and the results were used to simulate, design and fabricate novel actuators/motors. The developed actuators and performance will be described and discussed in this paper.

  14. Design and operation of off-gas cleaning systems at high level liquid waste conditioning facilities

    International Nuclear Information System (INIS)

    1988-01-01

    The immobilization of high level liquid wastes from the reprocessing of irradiated nuclear fuels is of great interest and serious efforts are being undertaken to find a satisfactory technical solution. Volatilization of fission product elements during immobilization poses the potential for the release of radioactive substances to the environment and necessitates effective off-gas cleaning systems. This report describes typical off-gas cleaning systems used in the most advanced high level liquid waste immobilization plants and considers most of the equipment and components which can be used for the efficient retention of the aerosols and volatile contaminants. In the case of a nuclear facility consisting of several different facilities, release limits are generally prescribed for the nuclear facility as a whole. Since high level liquid waste conditioning (calcination, vitrification, etc.) facilities are usually located at fuel reprocessing sites (where the majority of the high level liquid wastes originates), the off-gas cleaning system should be designed so that the airborne radioactivity discharge of the whole site, including the emission of the waste conditioning facility, can be kept below the permitted limits. This report deals with the sources and composition of different kinds of high level liquid wastes and describes briefly the main high level liquid waste solidification processes examining the sources and characteristics of the off-gas contaminants to be retained by the off-gas cleaning system. The equipment and components of typical off-gas systems used in the most advanced (large pilot or industrial scale) high level liquid waste solidification plants are described. Safety considerations for the design and safe operation of the off-gas systems are discussed. 60 refs, 31 figs, 17 tabs

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

    Directory of Open Access Journals (Sweden)

    Tian Li

    2017-03-01

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

  16. Vitamin and Amino Acid Auxotrophy in Anaerobic Consortia Operating under Methanogenic Conditions.

    Science.gov (United States)

    Hubalek, Valerie; Buck, Moritz; Tan, BoonFei; Foght, Julia; Wendeberg, Annelie; Berry, David; Bertilsson, Stefan; Eiler, Alexander

    2017-01-01

    Syntrophy among Archaea and Bacteria facilitates the anaerobic degradation of organic compounds to CH 4 and CO 2 . Particularly during aliphatic and aromatic hydrocarbon mineralization, as in the case of crude oil reservoirs and petroleum-contaminated sediments, metabolic interactions between obligate mutualistic microbial partners are of central importance. Using micromanipulation combined with shotgun metagenomic approaches, we describe the genomes of complex consortia within short-chain alkane-degrading cultures operating under methanogenic conditions. Metabolic reconstruction revealed that only a small fraction of genes in the metagenome-assembled genomes encode the capacity for fermentation of alkanes facilitated by energy conservation linked to H 2 metabolism. Instead, the presence of inferred lifestyles based on scavenging anabolic products and intermediate fermentation products derived from detrital biomass was a common feature. Additionally, inferred auxotrophy for vitamins and amino acids suggests that the hydrocarbon-degrading microbial assemblages are structured and maintained by multiple interactions beyond the canonical H 2 -producing and syntrophic alkane degrader-methanogen partnership. Compared to previous work, our report points to a higher order of complexity in microbial consortia engaged in anaerobic hydrocarbon transformation. IMPORTANCE Microbial interactions between Archaea and Bacteria mediate many important chemical transformations in the biosphere from degrading abundant polymers to synthesis of toxic compounds. Two of the most pressing issues in microbial interactions are how consortia are established and how we can modulate these microbial communities to express desirable functions. Here, we propose that public goods (i.e., metabolites of high energy demand in biosynthesis) facilitate energy conservation for life under energy-limited conditions and determine the assembly and function of the consortia. Our report suggests that an

  17. 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.

  18. 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.

  19. 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.

  20. Polyhydroxyalkanoates (PHA) production from phenol in an acclimated consortium: Batch study and impacts of operational conditions.

    Science.gov (United States)

    Zhang, Yi; Wusiman, Apiredan; Liu, Xiang; Wan, Chunli; Lee, Duu-Jong; Tay, JooHwa

    2018-02-10

    Microbial intracellular biopolymer PHA was synthesized from toxic pollutant phenol by an acclimated consortium. Various operational conditions were experimented for their effects on biomass growth and PHA accumulation. Carbon to nitrogen ratios from 5 to 40 (w/w) showed little impact, as did the levels of Fe, Ca and Mg in a short term. Acidic pH inhibited both growth and PHA synthesis, and an optimal dissolved oxygen level of 1-4 mg L -1 was identified. Low temperature (7 °C) significantly slowed but did not totally repress microbial activities. A 2% NaCl shock retarded reactions and 4% NaCl caused irreversible damage. Various initial phenol (S0) and biomass concentrations (X0) were combined to study the effect of food to microbe (F/M) ratio. High S0 and F/M exerted toxicity, reducing reaction rates but generating higher ultimate PHA wt% in biomass. Increasing X0 alleviated phenol inhibition and improved productivity and carbon conversion from phenol. A pseudo-optimized F/M ratio of 0.2-0.4 and a maximum PHA% rate of 1.15% min -1 were identified under medium S0/high X0. This study is the first to systematically investigate the feasibility of toxic industrial waste as the carbon source for PHA production, and likely the only one indicating potential for scaling-up and industrialization. Copyright © 2018 Elsevier B.V. All rights reserved.