WorldWideScience

Sample records for cascaded systems analysis

  1. Modified Electric System Cascade Analysis for optimal sizing of an autonomous Hybrid Energy System

    International Nuclear Information System (INIS)

    Zahboune, Hassan; Zouggar, Smail; 2, Research Institute of Chemical and Process Engineering – MŰKKI, Faculty of Information Technology, University of Pannonia, Egyetem u. 10, 8200, Veszprém (Hungary))" data-affiliation=" (Centre for Process Integration and Intensification – CPI2, Research Institute of Chemical and Process Engineering – MŰKKI, Faculty of Information Technology, University of Pannonia, Egyetem u. 10, 8200, Veszprém (Hungary))" >Yong, Jun Yow; 2, Research Institute of Chemical and Process Engineering – MŰKKI, Faculty of Information Technology, University of Pannonia, Egyetem u. 10, 8200, Veszprém (Hungary))" data-affiliation=" (Centre for Process Integration and Intensification – CPI2, Research Institute of Chemical and Process Engineering – MŰKKI, Faculty of Information Technology, University of Pannonia, Egyetem u. 10, 8200, Veszprém (Hungary))" >Varbanov, Petar Sabev; Elhafyani, Mohammed; Ziani, Elmostafa; Zarhloule, Yassine

    2016-01-01

    Ensuring sufficient generation for covering the power demand at minimum cost of the system are the goals of using renewable energy on isolated sites. Solar and wind capture are most widely used to generate clean electricity. Their availability is generally shifted in time. Therefore, it is advantageous to consider both sources simultaneously while designing an electrical power supply module of the studied system. A specific challenge in this context is to find the optimal sizes of the power generation and storage facilities, which would minimise the overall system cost and will still satisfy the demand. In this work, a new design algorithm is presented minimising the system cost, based on the Electric System Cascade Analysis and the Power Pinch Analysis. The algorithm takes as inputs the wind speed, solar irradiation, as well as cost data for the generation and storage facilities. It has also been applied to minimise the loss of power supply probability (LPSP) and to ensure the minimum of the used storage units without using outsourced electricity. The algorithm has been demonstrated on a case study with daily electrical energy demand of 18.7 kWh, resulting in a combination of PV Panels, wind turbine, and the batteries at minimal cost. For the conditions in Oujda city, the case study results indicate that it is possible to achieve 0.25 €/kWh Levelised Cost of Electricity for the generated power. - Highlights: • Renewable electricity systems for remote locations. • Optimal sizes of the power generation and storage facilities. • Improved Power Pinch procedure. • Achieves viable power cost levels.

  2. NEQ and task in dual-energy imaging: from cascaded systems analysis to human observer performance

    Science.gov (United States)

    Richard, Samuel; Siewerdsen, Jeffrey H.; Tward, Daniel J.

    2008-03-01

    The relationship between theoretical descriptions of imaging performance (Fourier-based cascaded systems analysis) and the performance of real human observers was investigated for various detection and discrimination tasks. Dual-energy (DE) imaging provided a useful basis for investigating this relationship, because it presents a host of acquisition and processing parameters that can significantly affect signal and noise transfer characteristics and, correspondingly, human observer performance. The detectability index was computed theoretically using: 1) cascaded systems analysis of the modulation transfer function (MTF), and noise-power spectrum (NPS) for DE imaging; 2) a Fourier description of imaging task; and 3.) integration of MTF, NPS, and task function according to various observer models, including Fisher-Hotelling and non-prewhitening with and without an eye filter and internal noise. Three idealized tasks were considered: sphere detection, shape discrimination (sphere vs. disk), and texture discrimination (uniform vs. textured disk). Using images of phantoms acquired on a prototype DE imaging system, human observer performance was assessed in multiple-alternative forced choice (MAFC) tests, giving an estimate of area under the ROC curve (A Ζ). The degree to which the theoretical detectability index correlated with human observer performance was investigated, and results agreed well over a broad range of imaging conditions, depending on the choice of observer model. Results demonstrated that optimal DE image acquisition and decomposition parameters depend significantly on the imaging task. These studies provide important initial validation that the detectability index derived theoretically by Fourier-based cascaded systems analysis correlates well with actual human observer performance and represents a meaningful metric for system optimization.

  3. Multi-objective optimization of a cascade refrigeration system: Exergetic, economic, environmental, and inherent safety analysis

    International Nuclear Information System (INIS)

    Eini, Saeed; Shahhosseini, Hamidreza; Delgarm, Navid; Lee, Moonyong; Bahadori, Alireza

    2016-01-01

    Highlights: • A multi-objective optimization is performed for a cascade refrigeration cycle. • The optimization problem considers inherently safe design as well as 3E analysis. • As a measure of inherent safety level a quantitative risk analysis is utilized. • A CO 2 /NH 3 cascade refrigeration system is compared with a CO 2 /C 3 H 8 system. - Abstract: Inherently safer design is the new approach to maximize the overall safety of a process plant. This approach suggests some risk reduction strategies to be implemented in the early stages of design. In this paper a multi-objective optimization was performed considering economic, exergetic, and environmental aspects besides evaluation of the inherent safety level of a cascade refrigeration system. The capital costs, the processing costs, and the social cost due to CO 2 emission were considered to be included in the economic objective function. Exergetic efficiency of the plant was considered as the second objective function. As a measure of inherent safety level, Quantitative Risk Assessment (QRA) was performed to calculate total risk level of the cascade as the third objective function. Two cases (ammonia and propane) were considered to be compared as the refrigerant of the high temperature circuit. The achieved optimum solutions from the multi–objective optimization process were given as Pareto frontier. The ultimate optimal solution from available solutions on the Pareto optimal curve was selected using Decision-Makings approaches. NSGA-II algorithm was used to obtain Pareto optimal frontiers. Also, three decision-making approaches (TOPSIS, LINMAP, and Shannon’s entropy methods) were utilized to select the final optimum point. Considering continuous material release from the major equipment in the plant, flash and jet fire scenarios were considered for the CO 2 /C 3 H 8 cycle and toxic hazards were considered for the CO 2 /NH 3 cycle. The results showed no significant differences between CO 2 /NH 3 and

  4. Cascade Chaotic System With Applications.

    Science.gov (United States)

    Zhou, Yicong; Hua, Zhongyun; Pun, Chi-Man; Chen, C L Philip

    2015-09-01

    Chaotic maps are widely used in different applications. Motivated by the cascade structure in electronic circuits, this paper introduces a general chaotic framework called the cascade chaotic system (CCS). Using two 1-D chaotic maps as seed maps, CCS is able to generate a huge number of new chaotic maps. Examples and evaluations show the CCS's robustness. Compared with corresponding seed maps, newly generated chaotic maps are more unpredictable and have better chaotic performance, more parameters, and complex chaotic properties. To investigate applications of CCS, we introduce a pseudo-random number generator (PRNG) and a data encryption system using a chaotic map generated by CCS. Simulation and analysis demonstrate that the proposed PRNG has high quality of randomness and that the data encryption system is able to protect different types of data with a high-security level.

  5. Optimal hybrid renewable energy design in autonomous system using Modified Electric System Cascade Analysis and Homer software

    International Nuclear Information System (INIS)

    Zahboune, Hassan; Zouggar, Smail; Krajacic, Goran; Varbanov, Petar Sabev; Elhafyani, Mohammed; Ziani, Elmostafa

    2016-01-01

    Highlights: • New approach to integrate the Pinch Analysis illustrated. • Total annual cost and loss of power supply probability are the objective functions. • The new Hybrid Cascade Table to determine the optimal system design. • The performances of the new method are compared with Homer Pro. - Abstract: In this paper, a method for designing hybrid electricity generation systems is presented. It is based on the Modified Electric System Cascade Analysis method. The Power Pinch analysis is used as a guideline for development of an isolated power supply system, which consists of photovoltaic panels, wind turbines and energy storage units. The design procedure uses a simulation model, developed using MATLAB/SIMULINK and applies the developed algorithms for obtaining an optimal design. A validation of the Modified Electric System Cascade Analysis method is performed by comparing the obtained results with those from the Homer Pro software. The procedure takes as inputs hourly wind speed, solar radiation, demands, as well as cost data, for the generation and storage facilities. It is also applied to minimize the loss of power supply probability and to minimize the number of storage units. The algorithm has been demonstrated with a case study on a site in Oujda city, with daily electrical energy demand of 18.7 kWh, resulting in a combination of photovoltaic panels, wind turbine and batteries at minimal cost. The results from the Modified Electric System Cascade Analysis and HOMER Pro show that both tools successfully identified the optimal solution with difference of 0.04% in produced energy, 5.4% in potential excess of electricity and 0.07% in the cost of the energy.

  6. Contingency Analysis of Cascading Line Outage Events

    Energy Technology Data Exchange (ETDEWEB)

    Thomas L Baldwin; Magdy S Tawfik; Miles McQueen

    2011-03-01

    As the US power systems continue to increase in size and complexity, including the growth of smart grids, larger blackouts due to cascading outages become more likely. Grid congestion is often associated with a cascading collapse leading to a major blackout. Such a collapse is characterized by a self-sustaining sequence of line outages followed by a topology breakup of the network. This paper addresses the implementation and testing of a process for N-k contingency analysis and sequential cascading outage simulation in order to identify potential cascading modes. A modeling approach described in this paper offers a unique capability to identify initiating events that may lead to cascading outages. It predicts the development of cascading events by identifying and visualizing potential cascading tiers. The proposed approach was implemented using a 328-bus simplified SERC power system network. The results of the study indicate that initiating events and possible cascading chains may be identified, ranked and visualized. This approach may be used to improve the reliability of a transmission grid and reduce its vulnerability to cascading outages.

  7. Signal-to-noise performance analysis of streak tube imaging lidar systems. I. Cascaded model.

    Science.gov (United States)

    Yang, Hongru; Wu, Lei; Wang, Xiaopeng; Chen, Chao; Yu, Bing; Yang, Bin; Yuan, Liang; Wu, Lipeng; Xue, Zhanli; Li, Gaoping; Wu, Baoning

    2012-12-20

    Streak tube imaging lidar (STIL) is an active imaging system using a pulsed laser transmitter and a streak tube receiver to produce 3D range and intensity imagery. The STIL has recently attracted a great deal of interest and attention due to its advantages of wide azimuth field-of-view, high range and angle resolution, and high frame rate. This work investigates the signal-to-noise performance of STIL systems. A theoretical model for characterizing the signal-to-noise performance of the STIL system with an internal or external intensified streak tube receiver is presented, based on the linear cascaded systems theory of signal and noise propagation. The STIL system is decomposed into a series of cascaded imaging chains whose signal and noise transfer properties are described by the general (or the spatial-frequency dependent) noise factors (NFs). Expressions for the general NFs of the cascaded chains (or the main components) in the STIL system are derived. The work presented here is useful for the design and evaluation of STIL systems.

  8. Cascaded H7 Current Source Converter Based Power Transmission Systems and Fault Analysis

    DEFF Research Database (Denmark)

    Wang, Weiqi; Gao, Feng; Yang, Yongheng

    2017-01-01

    , a high power trasmission technology based on cascaded H7 Current Source Converters (CSC) is proposed. The proposed system features classic CSC HVDC characteristics combined with superior efficiency characteristics. Control and operational schemes are presented. In addition, fault issues for the HVDC......The High Voltage Direct Current (HVDC) technology is considered as one of the most suitable solutions for bulky and long-distance power transmission. However, the state-of-the-art HVDC solution have certain limitations. This paper presents an overview of current HVDC technologies. More importantly...... system are analyzed. Simulation and experimental results are provided to verify the proposal....

  9. Thermodynamic Analysis and Optimization of Cascade Condensing Temperature of a CO2(R744)/R404A Cascade Refrigeration System

    OpenAIRE

    Yilmaz, Baris; Erdonmez, Nasuh; Sevindir, Mustafa Kemal; Mancuhan, Ebru

    2014-01-01

    Synthetic refrigerants are widely used in refrigeration applications. However, it is shown that such refrigerants have negative impacts on the ozone layer of atmosphere. Recently, natural refrigerants such as carbon dioxide and various hydrocarbon compounds are proposed to replace synthetic refrigerants in the industrial refrigeration systems. Carbon dioxide is one of the most promising and environment-friendly refrigerant solution due to its thermo-physical properties, low ozone depletion va...

  10. A Comparative Analysis of PID, Lead, Lag, Lead-Lag, and Cascaded Lead Controllers for a Drug Infusion System

    Science.gov (United States)

    Jadoon, Zuwwar Khan; Shakeel, Sobia; Saleem, Abeera; Shuja, Sana; ul-Hasan, Qadeer; Ali Riaz, Raja

    2017-01-01

    Goal The aim of this paper is to conduct a comprehensive comparative analysis between five different controllers for a drug infusion system in total intravenous anesthesia (TIVA) administration. Methods The proposed method models a dilution chamber with first order exponential decay characteristics to represent the pharmacokinetic decay of a drug. The dilution chamber is integrated with five different control techniques with a simulation-based comparative analysis performed between them. The design process is conducted using MATLAB SISOTOOL. Results The findings show that each controller has its own merits and demerits. The results generated using MATLAB signify and confirm the effectiveness of PI and cascaded lead controllers, with cascaded lead controller as the best control technique to automate and control the propofol delivery. Conclusion In this paper, different control techniques for measurement-based feedback-controlled propofol delivery is confirmed with promising results. Significance The comparative analysis showed that this drug infusion platform, merged with the proper control technique, will perform eminently in the field of total intravenous anesthesia. PMID:29312654

  11. Cascade vulnerability for risk analysis of water infrastructure.

    Science.gov (United States)

    Sitzenfrei, R; Mair, M; Möderl, M; Rauch, W

    2011-01-01

    One of the major tasks in urban water management is failure-free operation for at least most of the time. Accordingly, the reliability of the network systems in urban water management has a crucial role. The failure of a component in these systems impacts potable water distribution and urban drainage. Therefore, water distribution and urban drainage systems are categorized as critical infrastructure. Vulnerability is the degree to which a system is likely to experience harm induced by perturbation or stress. However, for risk assessment, we usually assume that events and failures are singular and independent, i.e. several simultaneous events and cascading events are unconsidered. Although failures can be causally linked, a simultaneous consideration in risk analysis is hardly considered. To close this gap, this work introduces the term cascade vulnerability for water infrastructure. Cascade vulnerability accounts for cascading and simultaneous events. Following this definition, cascade risk maps are a merger of hazard and cascade vulnerability maps. In this work cascade vulnerability maps for water distribution systems and urban drainage systems based on the 'Achilles-Approach' are introduced and discussed. It is shown, that neglecting cascading effects results in significant underestimation of risk scenarios.

  12. Optimization of contrast-enhanced breast imaging: Analysis using a cascaded linear system model.

    Science.gov (United States)

    Hu, Yue-Houng; Scaduto, David A; Zhao, Wei

    2017-01-01

    Contrast-enhanced (CE) breast imaging involves the injection contrast agents (i.e., iodine) to increase conspicuity of malignant lesions. CE imaging may be used in conjunction with digital mammography (DM) or digital breast tomosynthesis (DBT) and has shown promise in improving diagnostic specificity. Both CE-DM and CE-DBT techniques require optimization as clinical diagnostic tools. Physical factors including x-ray spectra, subtraction technique, and the signal from iodine contrast, must be considered to provide the greatest object detectability and image quality. We developed a cascaded linear system model (CLSM) for the optimization of CE-DM and CE-DBT employing dual energy (DE) subtraction or temporal (TE) subtraction. We have previously developed a CLSM for DBT implemented with an a-Se flat panel imager (FPI) and filtered backprojection (FBP) reconstruction algorithm. The model is used to track image quality metrics - modulation transfer function (MTF) and noise power spectrum (NPS) - at each stage of the imaging chain. In this study, the CLSM is extended for CE breast imaging. The effect of x-ray spectrum (varied by changing tube potential and the filter) and DE and TE subtraction techniques on breast structural noise was measured was studied and included as a deterministic source of noise in the CLSM. From the two-dimensional (2D) and three-dimensional (3D) MTF and NPS, the ideal observer signal-to-noise ratio (SNR), also known as the detectability index (d'), may be calculated. Using d' as a FOM, we discuss the optimization of CE imaging for the task of iodinated contrast object detection within structured backgrounds. Increasing x-ray energy was determined to decrease the magnitude of structural noise and not its correlation. By performing DE subtraction, the magnitude of the structural noise was further reduced at the expense of increased stochastic (quantum and electronic) noise. TE subtraction exhibited essentially no residual structural noise at the

  13. Reliability Worth Analysis of Distribution Systems Using Cascade Correlation Neural Networks

    DEFF Research Database (Denmark)

    Heidari, Alireza; Agelidis, Vassilios; Pou, Josep

    2018-01-01

    Reliability worth analysis is of great importance in the area of distribution network planning and operation. The reliability worth's precision can be affected greatly by the customer interruption cost model used. The choice of the cost models can change system and load point reliability indices...

  14. Exergy analysis of an adiabatic compressed air energy storage system using a cascade of phase change materials

    International Nuclear Information System (INIS)

    Tessier, Michael J.; Floros, Michael C.; Bouzidi, Laziz; Narine, Suresh S.

    2016-01-01

    Adiabatic compressed air energy storage is an emerging energy storage technology with excellent power and storage capacities. Currently, efficiencies are approximately 70%, in part due to the issue of heat loss during the compression stage. An exergy analysis is presented on a novel adiabatic compressed air energy storage system design utilizing a cascade of PCMs (phase change materials) for waste heat storage and recovery. The melting temperatures and enthalpies of the PCMs were optimized for this system and were shown to be dependent on the number of PCMs, the number of compression stages, and the maximum compression ratio. Efficiencies of storage and recovery using this approach are predicted to be as high as 85%, a 15% increase over current designs which do not incorporate PCMs. - Highlights: • A compressed air energy storage plant using phase change materials is proposed. • Increasing number of phase change materials increases roundtrip exergy efficiency. • A thermodynamic model allows melting points and latent heats required to be predicted.

  15. Exergy and energy analysis of three stage auto refrigerating cascade system using Zeotropic mixture for sustainable development

    International Nuclear Information System (INIS)

    Sivakumar, M.; Somasundaram, P.

    2014-01-01

    Highlights: • Zeotropic mixture of R290/R23/R14 works with 22.6% increased exergic efficiency. • Zeotropic mixture of mass fraction 0.218:0.346:0.436 offers COP of 0.253. • Since emphasis on COP, evaporating temperature 0.253 COP became the only alternate. • This is the only alternate refrigerant mixture for three stage ARC system at −97 °C. - Abstract: The Zeotropic mixture of environment friendly refrigerants (HC’s and HFC’s) being the only alternatives for working fluid in low temperature refrigeration system and hence three stage auto refrigerating cascade (ARC) system was studied for the existence using two combinations of (R290/R23/R14, R1270/R170/R14) three component Zeotropic mixture of five different refrigerants. The exergy analysis confirmed the existence of three stage ARC system. The performances of the system like Coefficient of Performance (COP), exergy lost, exergic efficiency, efficiency defect and the evaporating temperature achieved were investigated for different mass fractions in order to verify the effect of mass fraction on them. In accordance with the environmental issues and the process of sustainable development, the three component Zeotropic mixture of R290/R23/R14 with the mass fraction of 0.218:0.346:0.436 was performing better and hence can be suggested as an alternative refrigerant for three stage ARC system operating at very low evaporating temperature in the range of 176 K (−97 °C) at COP of 0.253 with 58.5% exergic efficiency (comparatively 22.6% increased value)

  16. Cascaded FSO-VLC Communication System

    KAUST Repository

    Gupta, Akash

    2017-08-28

    The proposed cascaded free space optics (FSO)-visible light communication (VLC) system consists of multiple VLC access points which caters the end users connected via a decode and forward (DF) relay to the FSO backhaul link. The FSO link is assumed to be affected by path-loss, pointing error and atmospheric turbulence while the end-to-end signal-to-noise ratio (SNR) of VLC downlinks are statistically characterized considering the randomness of users position. In this study, the novel closed form expressions of the statistics like probability density function (PDF) and cumulative distribution function (CDF) of the equivalent SNR are derived. Capitalizing on these, the closed form expressions for various performance metrics such as outage probability and error probability are provided. The simulation results are provided to verify the functional curves of mathematical analysis.

  17. Thermodynamic analysis of a novel ejector expansion transcritical CO2/N2O cascade refrigeration (NEETCR) system for cooling applications at low temperatures

    International Nuclear Information System (INIS)

    Megdouli, K.; Ejemni, N.; Nahdi, E.; Mhimid, A.; Kairouani, L.

    2017-01-01

    Natural substances are becoming very promising for long term alternative for refrigeration purposes. In this paper, two natural refrigerants have been proposed and analyzed for a novel ejector expansion transcritical cascade refrigeration (NEETCR) system. Nitrous oxide (N 2 O) is used in the low temperature circuit (LTC) whereas carbon dioxide (CO 2 ) is used in the high temperature circuit (HTC) of the NEETCR system. The reject of refrigerant vapor heat in the HTC is carried out through the use of transcritical carbon dioxide Rankine cycle. This produces work, which will be used to reduce the consumption work of compressors and feed pump thereby resulting in the improvement of the energy efficiency of the whole system. The simulation results were obtained by a computer FORTRAN program, where REFPROP 9 database was used to get the refrigerant thermodynamic properties. The simulation results showed that the (NEETCR) system had higher coefficient of performance and higher system second law efficiency compared to the EETCR system. An enhancement more than 9% in the COP and exergy efficiency of NEETCR system was found in comparison with EETCR system, when the cooling capacity and operating conditions of the two systems were the same. The increase of COP of NEETCR system and its efficiency along with the reduction of power consumption make it more practical for the use in cooling applications. - Highlights: • Exergy-energy analysis of two cascade refrigeration systems is conducted. • The input power of the NEETCR system is lower than that of the EETCR system. • The COP of the NEETCR system is higher than that of the EETCR system. • The NEETCR system is promise in cascade refrigeration system.

  18. Population analysis for atomic cascade decay processes

    International Nuclear Information System (INIS)

    Suto, Keiko; Kagawa, Takashi; Futaba, Kaoru

    1998-01-01

    Down-stream cascade decay processes in atomic systems are analyzed by solving a coupled rate equation for which an analytical solution for a population in each excited state is obtained. Some typical numerical examples for populations to interpret the decay passes connecting to features of optical or electron spectra observed in various collision experiments are also given. (author)

  19. Cascading effects of overfishing marine systems

    NARCIS (Netherlands)

    Scheffer, M.; Carpenter, S.; Young, de B.

    2005-01-01

    Profound indirect ecosystem effects of overfishing have been shown for coastal systems such as coral reefs and kelp forests. A new study from the ecosystem off the Canadian east coast now reveals that the elimination of large predatory fish can also cause marked cascading effects on the pelagic food

  20. Performance validation of a cascade control system through

    Directory of Open Access Journals (Sweden)

    A. Lakshmi Sangeetha

    2016-11-01

    Full Text Available The work analyzes the performance characteristics of a cascade control system when interconnected with various network architectures, such as Internet, mobile and wireless networks. The cascade control system consists of level and flow as primary and secondary variables, respectively. The web-enabled monitoring and control are realized using three techniques namely remote client–server, ActiveX-data socket and web publishing tool. Mobile network is established by interfacing the control system with a GSM modem which enables the monitoring of process parameters through mobile phones. The cascade control system is also monitored wirelessly from remote locations with advent of an indigenous wireless sensor node. The performance analysis proved that wireless monitoring may be considered as an effective alternate technique to the Internet-based communication especially for shorter distances.

  1. Cascaded recompression closed brayton cycle system

    Energy Technology Data Exchange (ETDEWEB)

    Pasch, James J.

    2018-01-02

    The present disclosure is directed to a cascaded recompression closed Brayton cycle (CRCBC) system and method of operation thereof, where the CRCBC system includes a compressor for compressing the system fluid, a separator for generating fluid feed streams for each of the system's turbines, and separate segments of a heater that heat the fluid feed streams to different feed temperatures for the system's turbines. Fluid exiting each turbine is used to preheat the fluid to the turbine. In an embodiment, the amount of heat extracted is determined by operational costs.

  2. Three-dimensional cascaded system analysis of a 50 µm pixel pitch wafer-scale CMOS active pixel sensor x-ray detector for digital breast tomosynthesis.

    Science.gov (United States)

    Zhao, C; Vassiljev, N; Konstantinidis, A C; Speller, R D; Kanicki, J

    2017-03-07

    High-resolution, low-noise x-ray detectors based on the complementary metal-oxide-semiconductor (CMOS) active pixel sensor (APS) technology have been developed and proposed for digital breast tomosynthesis (DBT). In this study, we evaluated the three-dimensional (3D) imaging performance of a 50 µm pixel pitch CMOS APS x-ray detector named DynAMITe (Dynamic Range Adjustable for Medical Imaging Technology). The two-dimensional (2D) angle-dependent modulation transfer function (MTF), normalized noise power spectrum (NNPS), and detective quantum efficiency (DQE) were experimentally characterized and modeled using the cascaded system analysis at oblique incident angles up to 30°. The cascaded system model was extended to the 3D spatial frequency space in combination with the filtered back-projection (FBP) reconstruction method to calculate the 3D and in-plane MTF, NNPS and DQE parameters. The results demonstrate that the beam obliquity blurs the 2D MTF and DQE in the high spatial frequency range. However, this effect can be eliminated after FBP image reconstruction. In addition, impacts of the image acquisition geometry and detector parameters were evaluated using the 3D cascaded system analysis for DBT. The result shows that a wider projection angle range (e.g.  ±30°) improves the low spatial frequency (below 5 mm -1 ) performance of the CMOS APS detector. In addition, to maintain a high spatial resolution for DBT, a focal spot size of smaller than 0.3 mm should be used. Theoretical analysis suggests that a pixelated scintillator in combination with the 50 µm pixel pitch CMOS APS detector could further improve the 3D image resolution. Finally, the 3D imaging performance of the CMOS APS and an indirect amorphous silicon (a-Si:H) thin-film transistor (TFT) passive pixel sensor (PPS) detector was simulated and compared.

  3. Null controllability of a cascade system of Schrodinger equations

    Directory of Open Access Journals (Sweden)

    Marcos Lopez-Garcia

    2016-03-01

    Full Text Available This article presents a control problem for a cascade system of two linear N-dimensional Schrodinger equations. We address the problem of null controllability by means of a control supported in a region not satisfying the classical geometrical control condition. The proof is based on the application of a Carleman estimate with degenerate weights to each one of the equations and a careful analysis of the system in order to prove null controllability with only one control force.

  4. Cascading failures in interdependent systems under a flow redistribution model

    Science.gov (United States)

    Zhang, Yingrui; Arenas, Alex; Yaǧan, Osman

    2018-02-01

    Robustness and cascading failures in interdependent systems has been an active research field in the past decade. However, most existing works use percolation-based models where only the largest component of each network remains functional throughout the cascade. Although suitable for communication networks, this assumption fails to capture the dependencies in systems carrying a flow (e.g., power systems, road transportation networks), where cascading failures are often triggered by redistribution of flows leading to overloading of lines. Here, we consider a model consisting of systems A and B with initial line loads and capacities given by {LA,i,CA ,i} i =1 n and {LB,i,CB ,i} i =1 n, respectively. When a line fails in system A , a fraction of its load is redistributed to alive lines in B , while remaining (1 -a ) fraction is redistributed equally among all functional lines in A ; a line failure in B is treated similarly with b giving the fraction to be redistributed to A . We give a thorough analysis of cascading failures of this model initiated by a random attack targeting p1 fraction of lines in A and p2 fraction in B . We show that (i) the model captures the real-world phenomenon of unexpected large scale cascades and exhibits interesting transition behavior: the final collapse is always first order, but it can be preceded by a sequence of first- and second-order transitions; (ii) network robustness tightly depends on the coupling coefficients a and b , and robustness is maximized at non-trivial a ,b values in general; (iii) unlike most existing models, interdependence has a multifaceted impact on system robustness in that interdependency can lead to an improved robustness for each individual network.

  5. Systems theory and cascades in developmental psychopathology.

    Science.gov (United States)

    Cox, Martha J; Mills-Koonce, Roger; Propper, Cathi; Gariépy, Jean-Louis

    2010-08-01

    In the wake of prominent theoreticians in developmental science, whose contributions we review in this article, many developmental psychologists came to endorse a systems approach to understanding how the individual, as it develops, establishes functional relationships to social ecological contexts that from birth to school entry rapidly increase in complexity. The concept of developmental cascade has been introduced in this context to describe lawful processes by which antecedent conditions may be related with varying probabilities to specified outcomes. These are understood as processes by which function at one level or in one domain of behavior affect the organization of competency in later developing domains of general adaptation. Here we propose a developmental sequence by which the developing child acquires regulative capacities that are key to adjustment to a society that demands considerable control of emotional and cognitive functions early in life. We report empirical evidence showing that the acquisition of regulative capacities may be understood as a cascade of shifts in control parameters induced by the progressive integration of biological, transactional, and socioaffective systems over development. We conclude by suggesting how the developmental process may be accessed for effective intervention in populations deemed "at risk" for later problems of psychosocial adjustment.

  6. The critical care cascade: a systems approach.

    Science.gov (United States)

    Ghosh, Rishi; Pepe, Paul

    2009-08-01

    To emphasize the evolving body of evidence that supports the need for a more seamless and interconnected continuum of patient care for a growing compendium of critical care conditions, starting in the prehospital and emergency department (ED) phases of management and continuing through ICU and rehabilitation services. The care of critically ill and injured patients has become increasingly complex. It now has been demonstrated that, for a number of such critical care conditions, optimal management not only relies heavily on the talents of highly coordinated, multidisciplinary teams, but it also may require shared responsibilities across a continuum of longitudinal care involving numerous specialties and departments. This continuum usually needs to begin in the prehospital and ED settings with management extending through specialized in-hospital diagnostic and interventional suites to traditional ICU and rehabilitation programs. In recent years, examples of these conditions have included the development of systems of care for trauma, cardiac arrest, myocardial infarction, stroke, sepsis syndromes, toxicology and other critical illnesses. Although the widespread implementation of such multidisciplinary, multispecialty critical care cascades of care has been achieved most commonly in trauma care, current healthcare delivery systems generally tend to employ compartmentalized organization for the majority of other critical care patients. Accordingly, optimal systematic care often breaks down in the management of these complex patients due to barriers such as lack of interoperable communication between teams, disjointed transfers between services, unnecessary time-consuming, re-evaluations and transitional pauses in time-dependent circumstances, deficiencies in cross-disciplinary education and quality assurance loops, and significant variability in patient care practices. Such barriers can lead to adverse outcomes in this fragile patient population. This article discusses

  7. Enantiomer separation in a cascaded micellar-enhanced ultrafiltration system

    NARCIS (Netherlands)

    Overdevest, P.E.M.; Hoenders, M.H.J.; Riet, van 't K.; Padt, van der A.; Keurentjes, J.T.F.

    2002-01-01

    The increasing demand for optically pure compounds (enantiomers) stimulates the development of new enantiomer separation processes on an industrial scale. The separation of enantiomers by ultrafiltration of enantioselective micelles was studied in a cascaded system. The feasibility of this

  8. On periodic orbits in discrete-time cascade systems

    Directory of Open Access Journals (Sweden)

    Huimin Li

    2006-01-01

    Full Text Available We present some results on existence, minimum period, number of periodic orbits, and stability of periodic orbits in discrete-time cascade systems. Some examples are presented to illustrate these results.

  9. Cascade Distillation System Design for Safety and Mission Assurance

    Science.gov (United States)

    Sarguisingh, Miriam; Callahan, Michael R.; Okon, Shira

    2015-01-01

    Per the NASA Human Health, Life Support and Habitation System Technology Area 06 report "crewed missions venturing beyond Low-Earth Orbit (LEO) will require technologies with improved reliability, reduced mass, self-sufficiency, and minimal logistical needs as an emergency or quick-return option will not be feasible".1 To meet this need, the development team of the second generation Cascade Distillation System (CDS 2.0) chose a development approach that explicitly incorporate consideration of safety, mission assurance, and autonomy. The CDS 2.0 preliminary design focused on establishing a functional baseline that meets the CDS core capabilities and performance. The critical design phase is now focused on incorporating features through a deliberative process of establishing the systems failure modes and effects, identifying mitigation strategies, and evaluating the merit of the proposed actions through analysis and test. This paper details results of this effort on the CDS 2.0 design.

  10. The performance of pip-cascade controler in HVAC system

    Directory of Open Access Journals (Sweden)

    Legweel Khaled M.B.

    2014-01-01

    Full Text Available Primitive controllers used in the early version for HVAC systems, like the on-off (Bang-Bang controller, are inefficient, inaccurate, unstable, and suffer from high-level mechanical wear. On the other hand, other controllers like PI and cascade controllers, overcome these disadvantages but when an offset response (inaccurate response occurs, power consumption will increase. In order to acquire better performance in the central air-conditioning system, PIP-cascade control is investigated in this paper and compared to the traditional PI and PID, in simulation of experimental data. The output of the system is predicted through disturbances. Based on the mathematical model of air-conditioning space, the simulations in this paper have found that the PIP-cascade controller has the capability of self-adapting to system changes and results in faster response and better performance.

  11. Optimization Control of Bidirectional Cascaded DC-AC Converter Systems

    DEFF Research Database (Denmark)

    Tian, Yanjun

    in bidirectional cascaded converter. This research work analyses the control strategies based on the topology of dual active bridges converter cascaded with a three phase inverter. It firstly proposed a dc link voltage and active power coordinative control method for this cascaded topology, and it can reduce dc....... The connections of the renewable energy sources to the power system are mostly through the power electronic converters. Moreover, for high controllability and flexibility, power electronic devices are gradually acting as the interface between different networks in power systems, promoting conventional power...... the bidirectional power flow in the distribution level of power systems. Therefore direct contact of converters introduces significant uncertainties to power system, especially for the stability and reliability. This dissertation studies the optimization control of the two stages directly connected converters...

  12. Cascade Storage and Delivery System for a Multi Mission Space Exploration Vehicle (MMSEV)

    Science.gov (United States)

    Yagoda, Evan; Swickrath, Michael; Stambaugh, Imelda

    2012-01-01

    NASA is developing a Multi Mission Space Exploration Vehicle (MMSEV) for missions beyond Low Earth Orbit (LEO). The MMSEV is a pressurized vehicle used to extend the human exploration envelope for Lunar, Near Earth Object (NEO), and Deep Space missions. The Johnson Space Center is developing the Environmental Control and Life Support System (ECLSS) for the MMSEV. The MMSEV s intended use is to support longer sortie lengths with multiple Extra Vehicular Activities (EVAs) on a higher magnitude than any previous vehicle. This paper presents an analysis of a high pressure oxygen cascade storage and delivery system that will accommodate the crew during long duration Intra Vehicular Activity (IVA) and capable of multiple high pressure oxygen fills to the Portable Life Support System (PLSS) worn by the crew during EVAs. A cascade is a high pressure gas cylinder system used for the refilling of smaller compressed gas cylinders. Each of the large cylinders are filled by a compressor, but the cascade system allows small cylinders to be filled without the need of a compressor. In addition, the cascade system is useful as a "reservoir" to accommodate low pressure needs. A regression model was developed to provide the mechanism to size the cascade systems subject to constraints such as number of crew, extravehicular activity duration and frequency, and ullage gas requirements under contingency scenarios. The sizing routine employed a numerical integration scheme to determine gas compressibility changes during depressurization and compressibility effects were captured using the Soave-Redlich-Kwong (SRK) equation of state. A multi-dimensional nonlinear optimization routine was used to find the minimum cascade tank system mass that meets the mission requirements. The sizing algorithms developed in this analysis provide a powerful framework to assess cascade filling, compressor, and hybrid systems to design long duration vehicle ECLSS architecture. 1

  13. Hybrid Cascading Outage Analysis of Extreme Events with Optimized Corrective Actions

    Energy Technology Data Exchange (ETDEWEB)

    Vallem, Mallikarjuna R.; Vyakaranam, Bharat GNVSR; Holzer, Jesse T.; Samaan, Nader A.; Makarov, Yuri V.; Diao, Ruisheng; Huang, Qiuhua; Ke, Xinda

    2017-10-19

    Power system are vulnerable to extreme contingencies (like an outage of a major generating substation) that can cause significant generation and load loss and can lead to further cascading outages of other transmission facilities and generators in the system. Some cascading outages are seen within minutes following a major contingency, which may not be captured exclusively using the dynamic simulation of the power system. The utilities plan for contingencies either based on dynamic or steady state analysis separately which may not accurately capture the impact of one process on the other. We address this gap in cascading outage analysis by developing Dynamic Contingency Analysis Tool (DCAT) that can analyze hybrid dynamic and steady state behavior of the power system, including protection system models in dynamic simulations, and simulating corrective actions in post-transient steady state conditions. One of the important implemented steady state processes is to mimic operator corrective actions to mitigate aggravated states caused by dynamic cascading. This paper presents an Optimal Power Flow (OPF) based formulation for selecting corrective actions that utility operators can take during major contingency and thus automate the hybrid dynamic-steady state cascading outage process. The improved DCAT framework with OPF based corrective actions is demonstrated on IEEE 300 bus test system.

  14. Optimized preventive replacement policy for large cascade systems

    International Nuclear Information System (INIS)

    Kretzen, H.H.

    1986-01-01

    The repair-bottleneck problem as a limiting factor for system reliability can be overcome. Design need only cover the steady state, wearout induced accumulations of failures being precluded by preventive replacements with subsequent recycling. As a result, a reliable system appears to be feasible on an economic basis, optimization in detail to be left to more precised cost-benefit studies. As a reference system the radio-frequency-generator cascade of a single-cell linear accelerator is considered. (DG)

  15. Cascade system using both trough system and dish system for power generation

    International Nuclear Information System (INIS)

    Zhang, Cheng; Zhang, Yanping; Arauzo, Inmaculada; Gao, Wei; Zou, Chongzhe

    2017-01-01

    Highlights: • A novel solar cascade system using both trough and dish collectors is proposed. • Heat rejected by the Stirling engines is collected by the condensed water. • The directions to increase the efficiency improvement has been pointed out • Influence of flow type of heating/cooling fluids of Stirling engines is considered. - Abstract: This paper represents a novel solar thermal cascade system using both trough and dish systems for power generation. An effective structure using the condensed fluid of Rankine cycle to cool the Stirling engines to use the heat released by Stirling engines was proposed. The cascade system model with different fluid circuits was developed. The models of some important components of the system, such as dish collector, trough collector and Stirling engine array, are presented with detail explanation in this paper. Corresponding stand-alone systems were also developed for comparison. Simulations were conducted with the models to find out efficiency difference between cascade system and corresponding stand-alone systems. The directions to increase the efficiency difference were also considered. Results show that the cascade system can achieve a higher efficiency with a high solar irradiance (>550 W/m 2 ). The flow type of fluids between heating and cooling Stirling engine array is also required to concern on designing a cascade system with Stirling engine array.

  16. Energy Cascade Analysis: from Subscale Eddies to Mean Flow

    Science.gov (United States)

    Cheikh, Mohamad Ibrahim; Wonnell, Louis; Chen, James

    2017-11-01

    Understanding the energy transfer between eddies and mean flow can provide insights into the energy cascade process. Much work has been done to investigate the energy cascade at the level of the smallest eddies using different numerical techniques derived from the Navier-Stokes equations. These methodologies, however, prove to be computationally inefficient when producing energy spectra for a wide range of length scales. In this regard, Morphing Continuum Theory (MCT) resolves the length-scales issues by assuming the fluid continuum to be composed of inner structures that play the role of subscale eddies. The current study show- cases the capabilities of MCT in capturing the dynamics of energy cascade at the level of subscale eddies, through a supersonic turbulent flow of Mach 2.93 over an 8× compression ramp. Analysis of the results using statistical averaging procedure shows the existence of a statistical coupling of the internal and translational kinetic energy fluctuations with the corresponding rotational kinetic energy of the subscale eddies, indicating a multiscale transfer of energy. The results show that MCT gives a new characterization of the energy cascade within compressible turbulence without the use of excessive computational resources. This material is based upon work supported by the Air Force Office of Scientific Research under Award Number FA9550-17-1-0154.

  17. Estimation for Expected Energy Not Served of Power Systems Using the Screening Methodology of Cascading Outages in South Korea

    Directory of Open Access Journals (Sweden)

    Bokyung Goo

    2017-12-01

    Full Text Available The uncertainty of complex power systems increases the possibility of large blackouts due to the expectations of physical events, such as equipment failures, protection failures, control actions failure, operator error, and cyber-attacks. Cascading outage is a sequence of dependent failures of individual components that successively weaken the power system. A procedure to identify and evaluate the initiating events and perform sequential cascading analysis is needed. In this paper, we propose a new screening methodology based on sequential contingency simulation of cascading outages, including probabilistic analysis and visualization model. Performance of a detail cascading analysis using practical power systems is suggested and discussed. The proposed screening methodology will play a key role in identifying the uncontrolled successive loss of system elements.

  18. Multi Agent System Based Wide Area Protection against Cascading Events

    DEFF Research Database (Denmark)

    Liu, Zhou; Chen, Zhe; Liu, Leo

    2012-01-01

    In this paper, a multi-agent system based wide area protection scheme is proposed in order to prevent long term voltage instability induced cascading events. The distributed relays and controllers work as a device agent which not only executes the normal function automatically but also can be mod...... the effectiveness of proposed protection strategy. The simulation results indicate that the proposed multi agent control system can effectively coordinate the distributed relays and controllers to prevent the long term voltage instability induced cascading events.......In this paper, a multi-agent system based wide area protection scheme is proposed in order to prevent long term voltage instability induced cascading events. The distributed relays and controllers work as a device agent which not only executes the normal function automatically but also can...... be modified to fulfill the extra function according to external requirements. The control center is designed as a highest level agent in MAS to coordinate all the lower agents to prevent the system wide voltage disturbance. A hybrid simulation platform with MATLAB and RTDS is set up to demonstrate...

  19. The Southern Washington Cascades magmatic system imaged with magnetotellurics

    Science.gov (United States)

    Bowles-martinez, E.; Bedrosian, P.; Schultz, A.; Hill, G. J.; Peacock, J.

    2016-12-01

    The goal of the interdisciplinary iMUSH project (Imaging Magma Under Saint Helens) is to image the magmatic system of Mount Saint Helens (MSH), and to determine the relationship of this system to the greater Cascades volcanic arc. We are especially interested in an anomalously conductive crustal zone between MSH and Mount Adams known as the Southern Washington Cascades Conductor (SWCC), which early studies interpreted as accreted sediments, but more recently has been interpreted as a broad region of partial melt. MSH is located 50 km west of the main arc and is the most active of the Cascade volcanoes. Its 1980 eruption highlighted the need to understand this potentially hazardous volcanic system. We use wideband magnetotelluric (MT) data collected in 2014-2015 along with data from earlier studies to create a 3D model of the electrical resistivity throughout the region, covering MSH as well as Mount Adams and Mount Rainier along the main volcanic arc. We look at not only the volcanoes themselves, but also their relationship to one another and to regional geologic structures. Preliminary modeling identifies several conductive features, including a mid-crustal conductive region between MSH and Mount Adams that passes below Indian Heaven Volcanic Field and coincides with a region with a high Vp/Vs ratio identified in the seismic component of iMUSH. This suggests that it could be magmatic, but does not preclude the possibility of conductive sediments. Synthesis of seismic and MT data to address this question is ongoing. We also note a conductive zone running north-south just west of MSH that is likely associated with fluids within faults of the Saint Helens Seismic Zone. We finally note that curvature of the conductive lineament that defines the main Cascade arc suggests that the boundary of magmatism is influenced by compression within the Yakima Fold and Thrust Belt, east and southeast of Mount Adams.

  20. Honeywell Cascade Distiller System Performance Testing Interim Results

    Science.gov (United States)

    Callahan, Michael R.; Sargusingh, Miriam

    2014-01-01

    The ability to recover and purify water through physiochemical processes is crucial for realizing long-term human space missions, including both planetary habitation and space travel. Because of their robust nature, distillation systems have been actively pursued as one of the technologies for water recovery. The Cascade Distillation System (CDS) is a vacuum rotary distillation system with potential for greater reliability and lower energy costs than existing distillation systems. The CDS was previously under development through Honeywell and NASA. In 2009, an assessment was performed to collect data to support down-selection and development of a primary distillation technology for application in a lunar outpost water recovery system. Based on the results of this testing, an expert panel concluded that the CDS showed adequate development maturity, TRL-4, together with the best product water quality and competitive weight and power estimates to warrant further development. The Advanced Exploration Systems (AES) Water Recovery Project (WRP) worked to address weaknesses identified by The Panel; namely bearing design and heat pump power efficiency. Testing at the NASA-JSC Advanced Exploration System Water Laboratory (AES Water Lab) using a prototype Cascade Distillation Subsystem (CDS) wastewater processor (Honeywell International, Torrance, Calif.) with test support equipment and control system developed by Johnson Space Center was performed to evaluate performance of the system with the upgrades. The CDS will also have been challenged with ISS analog waste streams and a subset of those being considered for Exploration architectures. This paper details interim results of the AES WRP CDS performance testing.

  1. Probabilistic study of cascading failures in complex interdependent lifeline systems

    International Nuclear Information System (INIS)

    Hernandez-Fajardo, Isaac; Dueñas-Osorio, Leonardo

    2013-01-01

    The internal complexity of lifeline systems and their standing interdependencies can operate in conjunction to amplify the negative effects of external disruptions. This paper introduces a simulation-based methodology to evaluate the joint impact of interdependence, component fragilities, and cascading failures in systemic fragility estimates. The proposed strategy uses a graph model of interdependent networks, an enhanced betweenness centrality for cascading failures approximation, and an interdependence model accounting for coupling uncertainty in the simulation of damage propagation for probabilistic performance assessment. This methodology is illustrated through its application to a realistic set of power and water networks subjected to earthquake scenarios and random failures. Test case results reveal two key insights: (1) the intensity of a perturbation influences interdependent systemic fragility by shaping the magnitudes of initial component damage and, sometimes counter-intuitively, the subsequent interdependence effects and (2) increasing local redundancy mitigates the effects of interdependence on systemic performance, but such intervention is incapable of eliminating interdependent effects completely. The previous insights provide basic guidelines for the design of systemic retrofitting policies. Additionally, the limitations of local capacity redundancy as a fragility control measure highlight the need for a critical assessment of intervention strategies in distributed infrastructure networks. Future work will assess the fragility-reduction efficiency of strategies involving informed manipulation of individual systemic topologies and the interdependence interfaces connecting them. - Highlights: ► An new simulation methodology effectively produces interdependent fragility assessments, IFAs. ► IFAs include perturbation action, cascading failures, and interdependent effects. ► Method tested using coupled networks exposed to earthquake and random

  2. Single phase cascaded H5 inverter with leakage current elimination for transformerless photovoltaic system

    DEFF Research Database (Denmark)

    Guo, Xiaoqiang; Jia, X.; Lu, Z.

    2016-01-01

    Leakage current reduction is one of the important issues for the transformelress PV systems. In this paper, the transformerless single-phase cascaded H-bridge PV inverter is investigated. The common mode model for the cascaded H4 inverter is analyzed. And the reason why the conventional cascade H...

  3. Lack of plasma kallikrein-kinin system cascade in teleosts.

    Directory of Open Access Journals (Sweden)

    Marty Kwok-Shing Wong

    Full Text Available The kallikrein-kinin system (KKS consists of two major cascades in mammals: "plasma KKS" consisting of high molecular-weight (HMW kininogen (KNG, plasma kallikrein (KLKB1, and bradykinin (BK; and "tissue KKS" consisting of low molecular-weight (LMW KNG, tissue kallikreins (KLKs, and [Lys(0]-BK. Some components of the KKS have been identified in the fishes, but systematic analyses have not been performed, thus this study aims to define the KKS components in teleosts and pave a way for future physiological and evolutionary studies. Through a combination of genomics, molecular, and biochemical methods, we showed that the entire plasma KKS cascade is absent in teleosts. Instead of two KNGs as found in mammals, a single molecular weight KNG was found in various teleosts, which is homologous to the mammalian LMW KNG. Results of molecular phylogenetic and synteny analyses indicated that the all current teleost genomes lack KLKB1, and its unique protein structure, four apple domains and one trypsin domain, could not be identified in any genome or nucleotide databases. We identified some KLK-like proteins in teleost genomes by synteny and conserved domain analyses, which could be the orthologs of tetrapod KLKs. A radioimmunoassay system was established to measure the teleost BK and we found that [Arg(0]-BK is the major circulating form instead of BK, which supports that the teleost KKS is similar to the mammalian tissue KKS. Coincidently, coelacanths are the earliest vertebrate that possess both HMW KNG and KLKB1, which implies that the plasma KKS could have evolved in the early lobe-finned fish and descended to the tetrapod lineage. The co-evolution of HMW KNG and KLKB1 in lobe-finned fish and early tetrapods may mark the emergence of the plasma KKS and a contact activation system in blood coagulation, while teleosts may have retained a single KKS cascade.

  4. FY 2005 Quantum Cascade Laser Alignment System Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Myers, Tanya L.; Cannon, Bret D.; Wojcik, Michael D.; Broocks, Bryan T.; Stewart, Timothy L.; Hatchell, Brian K.

    2006-01-11

    The Alignment Lasers Task of Pacific Northwest National Laboratory's (PNNL's) Remote Spectroscopy Project (Project PL211I) is a co-funded project between DOE NA-22 and a Classified Client. This project, which began in the second half of FY03, involved building and delivering a Quantum Cascade (QC) Laser Alignment System to be used for testing the pupil alignment of an infrared sensor by measuring the response from four pairs of diametrically opposed QC lasers. PNNL delivered the system in FY04 and provided technical assistance in FY05 culminating into a successful demonstration of the system. This project evolved from the Laser Development Task of PL211I, which is involved in developing novel laser technology to support development of advanced chemical sensors for detecting the proliferation of nuclear weapons. The laser systems are based on quantum cascade (QC) lasers, a new semiconductor source in the infrared. QC lasers can be tailored to emit light throughout the infrared region (3.5 ? 17 ?m) and have high output power and stability. Thus, these lasers provide an infrared source with superb power and spectral stability enabling them to be used for applications such as alignment and calibration in addition to chemical sensing.

  5. PARAMETRIC STUDY OF ENERGY, EXERGY AND THERMOECONOMIC ANALYSES ON VAPOR-COMPRESSION SYSTEM CASCADED WITH LIBR/WATER AND NH3/WATER ABSORBTION CASCADE REFRIGERATION CYCLE

    Directory of Open Access Journals (Sweden)

    ahmet selim dalkilic

    2017-03-01

    Full Text Available Energy savings on cooling systems can be performed by using novel refrigeration cycles. For this aim, vapour compression-vapour absorption cascade refrigeration systems can be considered as substitute to single-stage vapour compression refrigeration systems. Renewable energy sources of geothermal and solar heat, waste heat of processes have been used by these cycles to provide cooling and they also require less electrical energy than vapour compression cycles having alternative refrigerants. In this study, a vapour compression (VC and vapour absorption (VA cascade systems are analysed with the second law analysis for varied cooling capacities. While lithium bromide-water and NH3/H2O are the working fluids in VA part, various refrigerants are used in VC section. The refrigerants of R134a and R600a, R410A and R407C are tested as drop in alternatives for R12 and R22, respectively. The effects of alteration in cooling capacity, superheating and sub cooling in VC part, temperature in the generator and absorber, and degree of overlap in cascade condenser in VA part on the coefficient of system performance are studied. Validation of the results have been performed by the values given in the literature. Improvement in COP of VC, VA and cascade system are obtained separately. According to the analyses, cascade systems’ COP values increase with increasing the temperatures of generator and evaporator and they also increase with decreasing the condenser and absorber temperatures. Moreover, the generator has the highest exergy destruction rates, second and third one were the condenser and absorber, respectively. Electricity consumption and payback period are also determined considering the various parameters of the study.

  6. Reliability Evaluation of Machine Center Components Based on Cascading Failure Analysis

    Science.gov (United States)

    Zhang, Ying-Zhi; Liu, Jin-Tong; Shen, Gui-Xiang; Long, Zhe; Sun, Shu-Guang

    2017-07-01

    In order to rectify the problems that the component reliability model exhibits deviation, and the evaluation result is low due to the overlook of failure propagation in traditional reliability evaluation of machine center components, a new reliability evaluation method based on cascading failure analysis and the failure influenced degree assessment is proposed. A direct graph model of cascading failure among components is established according to cascading failure mechanism analysis and graph theory. The failure influenced degrees of the system components are assessed by the adjacency matrix and its transposition, combined with the Pagerank algorithm. Based on the comprehensive failure probability function and total probability formula, the inherent failure probability function is determined to realize the reliability evaluation of the system components. Finally, the method is applied to a machine center, it shows the following: 1) The reliability evaluation values of the proposed method are at least 2.5% higher than those of the traditional method; 2) The difference between the comprehensive and inherent reliability of the system component presents a positive correlation with the failure influenced degree of the system component, which provides a theoretical basis for reliability allocation of machine center system.

  7. Thermoeconomic Optimization of Cascade Refrigeration System Using Mixed Carbon Dioxide and Hydrocarbons at Low Temperature Circuit

    Directory of Open Access Journals (Sweden)

    Nasruddin Nasruddin

    2016-12-01

    Full Text Available Many applications and industrial processes require very low cooling temperature, such as cold storage in the biomedical field, requiring temperature below -80 °C. However,single-cycle refrigeration systems can only achieve the effective cooling temperature of -40 °C and, also, the performance of the cycle will decrease drastically for cooling temperatures lower than -35°C. Currently, most of cascade refrigeration systems use refrigerants that have ozone depletion potential (ODP and global warming potential (GWP, therefore, in this study, a cascade system is simulated using a mixture of environmentally friendly refrigerants, namely, carbon dioxide and a hydrocarbon (propane, ethane or ethylene as the refrigerant of the low temperature circuit. A thermodynamic analysis is performed to determine the optimal composition of the mixture of carbon dioxide and hydrocarbons in the scope of certain operating parameters. In addition, an economic analysis was also performed to determine the annual cost to be incurred from the cascade refrigeration system. The multi-objective/thermoeconomic optimization points out optimal operating parameter values of the system, to addressing both exergy efficiency and its relation to the costs to be incurred.

  8. Analysis of car-following model with cascade compensation strategy

    Science.gov (United States)

    Zhu, Wen-Xing; Zhang, Li-Dong

    2016-05-01

    Cascade compensation mechanism was designed to improve the dynamical performance of traffic flow system. Two compensation methods were used to study unit step response in time domain and frequency characteristics with different parameters. The overshoot and phase margins are proportional to the compensation parameter in an underdamped condition. Through the comparison we choose the phase-lead compensation method as the main strategy in suppressing the traffic jam. The simulations were conducted under two boundary conditions to verify the validity of the compensator. The conclusion can be drawn that the stability of the system is strengthened with increased phase-lead compensation parameter. Moreover, the numerical simulation results are in good agreement with analytical results.

  9. High efficiency heat transport and power conversion system for cascade

    International Nuclear Information System (INIS)

    Maya, I.; Bourque, R.F.; Creedon, R.L.; Schultz, K.R.

    1985-02-01

    The Cascade ICF reactor features a flowing blanket of solid BeO and LiAlO 2 granules with very high temperature capability (up to approx. 2300 K). The authors present here the design of a high temperature granule transport and heat exchange system, and two options for high efficiency power conversion. The centrifugal-throw transport system uses the peripheral speed imparted to the granules by the rotating chamber to effect granule transport and requires no additional equipment. The heat exchanger design is a vacuum heat transfer concept utilizing gravity-induced flow of the granules over ceramic heat exchange surfaces. A reference Brayton power cycle is presented which achieves 55% net efficiency with 1300 K peak helium temperature. A modified Field steam cycle (a hybrid Rankine/Brayton cycle) is presented as an alternate which achieves 56% net efficiency

  10. Thermodynamic analysis of a thermally operated cascade sorption heat pump for continuous cold generation

    Energy Technology Data Exchange (ETDEWEB)

    Muthukumar, P.; Lakshmi, D.V.N. [Department of Mechanical Engineering, Indian Institute of Technology, Guwahati – 781039 (India)

    2013-07-01

    In this paper, the thermodynamic analysis of a cascade sorption system consists of a two-stage metal hydride heat pump as topping cycle and a single-stage lithium bromide water system as bottom cycle is presented. The effects of various operating temperatures such as driving heat, heat release and refrigeration temperatures, and design parameters such as ratio of metal hydride mass to reactor mass and sensible heat exchange factor on the combined coefficient of performance (COP) of the cascade cycle, and specific cooling power (SCP) and total cold output of the metal hydride heat pump cycle are presented. It is observed that the combined COP is found to increase with heat release and refrigeration temperatures and however, decreases with driving heat temperature. Increase of sensible heat exchange factor improves the system performances significantly. Reduction in mass ratio from 0.5 to 0.1 improves the combined COP of the cascade system by about 10 %. The maximum predicted combined COP of the system is about 1.66 at the driving heat, heat release and refrigeration temperatures of 270 deg C, 125 deg C and 12deg C, respectively.

  11. Model and Study on Cascade Control System Based on IGBT Chopping Control

    Science.gov (United States)

    Niu, Yuxin; Chen, Liangqiao; Wang, Shuwen

    2018-01-01

    Thyristor cascade control system has a wide range of applications in the industrial field, but the traditional cascade control system has some shortcomings, such as a low power factor, serious harmonic pollution. In this paper, not only analyzing its system structure and working principle, but also discussing the two main factors affecting the power factor. Chopping-control cascade control system, adopted a new power switching device IGBT, which could overcome traditional cascade control system’s two main drawbacks efficiently. The basic principle of this cascade control system is discussed in this paper and the model of speed control system is built by using MATLAB/Simulink software. Finally, the simulation results of the system shows that the system works efficiently. This system is worthy to be spread widely in engineering application.

  12. DECREASING OF WATER TROPHY IN CASCADE SYSTEMS, ON EXAMPLE OF THE SOŁA RIVER DAM CASCADE (SOUTHERN POLAND

    Directory of Open Access Journals (Sweden)

    Ewa Jachniak

    2014-10-01

    Full Text Available In this thesis the subject of water self-purification in cascade systems of water reservoirs was engaged. The results of hydrobiological research of three dam reservoirs (Tresna, Porąbka and Czaniec, creating the Soła river dam cascade were presented. The trophic status of these reservoirs was defined on the grounds of the concentration of chlorophyll a, biomass of phytoplankton and occurrence of indicating species of planktonic algae. The results of research indicated on decreasing of water trophy in the layout from the highest into the lowest reservoir of the cascade. The average concentrations of chlorophyll a amounted appropriately 19,99 μg·dm-3, 8,74 μg·dm-3 and 4,29 μg·dm-3, instead the average biomass of phytoplankton amounted appropriately 4,1 mg·dm-3, 3,4 mg·dm-3 and 0,1 mg·dm-3. The observed species of algae confirmed occurrence of differences between reservoirs. In Tresna reservoir more species of phytoplankton indicating for eutrophy were thrived, instead in Porąbka and Czaniec reservoirs the species occurring in oligomesotrophic water thrived. Water self-purification in the Soła river dam cascade expressed decreasing of their fertility is important for water management of the region, because the Czaniec reservoir fulfill a function of water-supply reservoir.

  13. Coalescence cascade of dissipative solitons in parametrically driven systems

    Science.gov (United States)

    Clerc, M. G.; Coulibaly, S.; Gordillo, L.; Mujica, N.; Navarro, R.

    2011-09-01

    Parametrically driven spatially extended systems exhibit uniform oscillations which are modulationally unstable. The resulting periodic state evolves to the creation of a gas of dissipative solitons. Driven by the interaction of dissipative solitons, the multisoliton state undergoes a cascade of coalescence processes, where the average soliton separation distance obeys a temporal self-similar law. Starting from the soliton pair interaction law, we have derived analytically and characterized the law of this multisoliton coarsening process. A comparison of numerical results obtained with different models such as the parametrically driven damped nonlinear Schrödinger equation, a vertically driven chain of pendula, and a parametrically forced magnetic wire, shows remarkable agreement. Both phenomena, the pair interaction law and the coarsening process, are also observed experimentally in a quasi-one-dimensional layer of Newtonian fluid which is oscillated vertically.

  14. Risk Assessment of Power System Considering Frequency Dynamics and Cascading Process

    Directory of Open Access Journals (Sweden)

    Chao Luo

    2018-02-01

    Full Text Available Frequency security is vital to the safety of power systems and has been scrutinized for many years. The conventional frequency security analysis only checks whether the frequency after anticipated initial failures can remain in the normal range based on some aggregated models, but the influence of potential cascading failures has not been considered yet. This is not enough, especially when the modern power system suffers the increasing threat of cascading failures. Therefore, this paper proposes a novel frequency simulation model considering the influence of cascading failure to reveal the security level of power systems comprehensively. The proposed model is based on a platform on which the frequency dynamics and the power flow distributions can be calculated jointly. Moreover, simulation models of protection devices and some supervisory operation-control schemes are also taken into account. Case studies validate the effectiveness of the proposed model on the IEEE 39-bus system. Moreover, the results of some further probabilistic simulations under different operation parameters are obtained, which show the great significance of improving the frequency regulation performance to cope with challenges of blackouts.

  15. Participant intimacy: A cluster analysis of the intranuclear cascade

    International Nuclear Information System (INIS)

    Cugnon, J.; Knoll, J.; Randrup, J.

    1981-01-01

    The intranuclear cascade for relativistic nuclear collisions is analyzed in terms of clusters consisting of groups of nucleons which are dynamically linked to each other by violent interactions. The formation cross sections for the different cluster types as well as their intrinsic dynamics are studied and compared with the predictions of the linear cascade model ( rows-on-rows ). (orig.)

  16. Electromagnetic Transient Response Analysis of DFIG under Cascading Grid Faults Considering Phase Angel Jumps

    DEFF Research Database (Denmark)

    Wang, Yun; Wu, Qiuwei

    2014-01-01

    This paper analysis the electromagnetic transient response characteristics of DFIG under symmetrical and asymmetrical cascading grid fault conditions considering phaseangel jump of grid. On deriving the dynamic equations of the DFIG with considering multiple constraints on balanced and unbalanced...... conditions, phase angel jumps, interval of cascading fault, electromagnetic transient characteristics, the principle of the DFIG response under cascading voltage fault can be extract. The influence of grid angel jump on the transient characteristic of DFIG is analyzed and electromagnetic response...

  17. Multiagent System-Based Wide-Area Protection and Control Scheme against Cascading Events

    DEFF Research Database (Denmark)

    Liu, Zhou; Chen, Zhe; Sun, Haishun

    2015-01-01

    In this paper, a multi agent system (MAS) based wide area protection and control scheme is proposed to deal with the long term voltage instability induced cascading trips. Based on sensitivity analysis between the relay operation margin and power system state variables, an optimal emergency control...... strategy. A hybrid simulation platform based on LabVIEW and real time digital simulator (RTDS) is set up to simulate a blackout case in the power system of Eastern Denmark and to demonstrate the effectiveness of the proposed MAS based protection strategy....

  18. Advanced exergy analysis on a modified auto-cascade freezer cycle with an ejector

    International Nuclear Information System (INIS)

    Bai, Tao; Yu, Jianlin; Yan, Gang

    2016-01-01

    This paper presents a study on a modified ejector enhanced auto-cascade freezer cycle with conventional thermodynamic and advanced exergy analysis methods. The energetic analysis shows that the modified cycle exhibits better performance than the conventional auto-cascade freezer cycle, and the system COP and volumetric refrigeration capacity could be improved by 19.93% and 28.42%. Furthermore, advanced exergy analysis is adopted to better evaluate the performance of the proposed cycle. The exergy destruction within a system component is split into endogenous/exogenous and unavoidable/avoidable parts in the advanced exergy analysis. The results show that the compressor with the largest avoidable endogenous exergy destruction has highest improvement priority, followed by the condenser, evaporator and ejector, which is different from the conclusion obtained from the conventional exergy analysis. The evaporator/condenser greatly affects the exogenous exergy destruction within the system components, and the compressor has large impact on the exergy destruction within the condenser. Improving the efficiencies of the compressor efficiency and the ejector could effectively reduce the corresponding avoidable endogenous exergy destruction. The exergy destruction within the evaporator almost entirely belongs to the endogenous part, and reducing the temperature difference at the evaporator is the main approach of reducing its exergy destruction. - Highlights: • A modified ejector enhanced auto-cascade freezer cycle is proposed. • Conventional and advanced exergy analyses are performed in this study. • Compressor should be firstly improved first, followed by condenser and evaporator. • Interactions among the system components are assessed with advanced exergy analysis.

  19. System design description for the CPDF Cascade Control Room: SDD-7

    International Nuclear Information System (INIS)

    1980-05-01

    The Cascade Control Room (CCR) is the nerve center of the Centrifuge Plant Demonstration Facility (CPDF). The components within the CCR monitor and control those variables necessary for the safe and efficient operation of the cascade during normal and emergency operation. The CCR interfaces with all the process systems and most of the support systems, receiving and transmitting data signals at frequent intervals during all phases of cascade operation. The main component in the CCR is the control room computer (CRC), which serves as the primary interface between the CCR and the process and support systems. The other components in the CCR are: (1) instrumentation cabinets; (2) operator control panel; (3) mass spectrometer - tails (MST); (4) mass spectrometer - product (MSP); (5) product light gas analyzer (PLGA); and (6) the operator. CCR instrumentation provides audible and visual alarms of abnormal events detected by process and utilities instrumentation or by the CRC. Records of alarms and process and utility variables are continuously generated in the CCR. Operator control functions are performed through the CRC or at the various instrument cabinets. Analysis of the current operating status of the plant is aided by the CRC and CCR instrumentation. 14 figs., 2 tabs

  20. Packaged, cascadable wideband monolithic feedback amplifiers for radar systems applications

    OpenAIRE

    Alleva, V.; Calori, M.; Cetronio, A.; Lanzieri, C.; Proietti, C.; Rapisarda, S.

    1990-01-01

    Design criteria and fabrication of a packaged, monolithic, cascadable, feedback amplifier are presented. The good performances in term of bandwidth, gain, flatness, reproducibility and reliability makes this component highly suitable for many radar applications.

  1. A novel anti-windup framework for cascade control systems: an application to underactuated mechanical systems.

    Science.gov (United States)

    Mehdi, Niaz; Rehan, Muhammad; Malik, Fahad Mumtaz; Bhatti, Aamer Iqbal; Tufail, Muhammad

    2014-05-01

    This paper describes the anti-windup compensator (AWC) design methodologies for stable and unstable cascade plants with cascade controllers facing actuator saturation. Two novel full-order decoupling AWC architectures, based on equivalence of the overall closed-loop system, are developed to deal with windup effects. The decoupled architectures have been developed, to formulate the AWC synthesis problem, by assuring equivalence of the coupled and the decoupled architectures, instead of using an analogy, for cascade control systems. A comparison of both AWC architectures from application point of view is provided to consolidate their utilities. Mainly, one of the architecture is better in terms of computational complexity for implementation, while the other is suitable for unstable cascade systems. On the basis of the architectures for cascade systems facing stability and performance degradation problems in the event of actuator saturation, the global AWC design methodologies utilizing linear matrix inequalities (LMIs) are developed. These LMIs are synthesized by application of the Lyapunov theory, the global sector condition and the ℒ2 gain reduction of the uncertain decoupled nonlinear component of the decoupled architecture. Further, an LMI-based local AWC design methodology is derived by utilizing a local sector condition by means of a quadratic Lyapunov function to resolve the windup problem for unstable cascade plants under saturation. To demonstrate effectiveness of the proposed AWC schemes, an underactuated mechanical system, the ball-and-beam system, is considered, and details of the simulation and practical implementation results are described. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  2. Cascade Optimization Strategy for Aircraft and Air-Breathing Propulsion System Concepts

    Science.gov (United States)

    Patnaik, Surya N.; Lavelle, Thomas M.; Hopkins, Dale A.; Coroneos, Rula M.

    1996-01-01

    Design optimization for subsonic and supersonic aircraft and for air-breathing propulsion engine concepts has been accomplished by soft-coupling the Flight Optimization System (FLOPS) and the NASA Engine Performance Program analyzer (NEPP), to the NASA Lewis multidisciplinary optimization tool COMETBOARDS. Aircraft and engine design problems, with their associated constraints and design variables, were cast as nonlinear optimization problems with aircraft weight and engine thrust as the respective merit functions. Because of the diversity of constraint types and the overall distortion of the design space, the most reliable single optimization algorithm available in COMETBOARDS could not produce a satisfactory feasible optimum solution. Some of COMETBOARDS' unique features, which include a cascade strategy, variable and constraint formulations, and scaling devised especially for difficult multidisciplinary applications, successfully optimized the performance of both aircraft and engines. The cascade method has two principal steps: In the first, the solution initiates from a user-specified design and optimizer, in the second, the optimum design obtained in the first step with some random perturbation is used to begin the next specified optimizer. The second step is repeated for a specified sequence of optimizers or until a successful solution of the problem is achieved. A successful solution should satisfy the specified convergence criteria and have several active constraints but no violated constraints. The cascade strategy available in the combined COMETBOARDS, FLOPS, and NEPP design tool converges to the same global optimum solution even when it starts from different design points. This reliable and robust design tool eliminates manual intervention in the design of aircraft and of air-breathing propulsion engines where it eases the cycle analysis procedures. The combined code is also much easier to use, which is an added benefit. This paper describes COMETBOARDS

  3. Composite and Cascaded Generalized-K Fading Channel Modeling and Their Diversity and Performance Analysis

    KAUST Repository

    Ansari, Imran Shafique

    2010-12-01

    The introduction of new schemes that are based on the communication among nodes has motivated the use of composite fading models due to the fact that the nodes experience different multipath fading and shadowing statistics, which subsequently determines the required statistics for the performance analysis of different transceivers. The end-to-end signal-to-noise-ratio (SNR) statistics plays an essential role in the determination of the performance of cascaded digital communication systems. In this thesis, a closed-form expression for the probability density function (PDF) of the end-end SNR for independent but not necessarily identically distributed (i.n.i.d.) cascaded generalized-K (GK) composite fading channels is derived. The developed PDF expression in terms of the Meijer-G function allows the derivation of subsequent performance metrics, applicable to different modulation schemes, including outage probability, bit error rate for coherent as well as non-coherent systems, and average channel capacity that provides insights into the performance of a digital communication system operating in N cascaded GK composite fading environment. Another line of research that was motivated by the introduction of composite fading channels is the error performance. Error performance is one of the main performance measures and derivation of its closed-form expression has proved to be quite involved for certain systems. Hence, in this thesis, a unified closed-form expression, applicable to different binary modulation schemes, for the bit error rate of dual-branch selection diversity based systems undergoing i.n.i.d. GK fading is derived in terms of the extended generalized bivariate Meijer G-function.

  4. Evaluation of refrigerating and air-conditioning technologies in heat cascading systems under the carbon dioxide emissions constraint: the proposal of the energy cascade balance table

    International Nuclear Information System (INIS)

    Shimazaki, Yoichi

    2003-01-01

    The aim of this study was to evaluate the refrigerating and air-conditioning technologies in cases of introducing both heat cascading systems and thermal recycling systems in industries located around urban areas. It is necessary to introduce heat cascading systems in the industrial sector in Japan to reduce carbon dioxide emissions. The concept of heat cascading is the multi-stage use of thermal energy by temperature level. This paper introduces three energy policies for introducing the heat cascading systems. The author develops an energy cascade model based on linear programming so as to minimize the total system costs with carbon taxes. Five cases are investigated. Carbon dioxide emission constraints result in the enhancement of heat cascading, where high temperature heat is supplied for process heating while low temperature heat is shifted to refrigeration. It was found that increasing the amount of garbage combustion waste heat could reduce electric power for the turbo compression refrigerator by promoting waste heat driven ammonia absorption refrigerator. In addition, this study proposes an energy cascade balance table with respect to the temperature level

  5. NONLINEAR SYSTEM MODELING USING SINGLE NEURON CASCADED NEURAL NETWORK FOR REAL-TIME APPLICATIONS

    Directory of Open Access Journals (Sweden)

    S. Himavathi

    2012-04-01

    Full Text Available Neural Networks (NN have proved its efficacy for nonlinear system modeling. NN based controllers and estimators for nonlinear systems provide promising alternatives to the conventional counterpart. However, NN models have to meet the stringent requirements on execution time for its effective use in real time applications. This requires the NN model to be structurally compact and computationally less complex. In this paper a parametric method of analysis is adopted to determine the compact and faster NN model among various neural network architectures. This work proves through analysis and examples that the Single Neuron Cascaded (SNC architecture is distinct in providing compact and simpler models requiring lower execution time. The unique structural growth of SNC architecture enables automation in design. The SNC Network is shown to combine the advantages of both single and multilayer neural network architectures. Extensive analysis on selected architectures and their models for four benchmark nonlinear theoretical plants and a practical application are tested. A performance comparison of the NN models is presented to demonstrate the superiority of the single neuron cascaded architecture for online real time applications.

  6. Dynamics of cascade three-level system interacting with the ...

    Indian Academy of Sciences (India)

    Abstract. We study the exact solutions of the cascade three-level atom interacting with a single mode classical and quantized field with different initial conditions of the atom. For the semiclassical model, it is found that if the atom is initially in the middle level, the time-dependent populations of the upper and lower levels are ...

  7. Design and optimization of cascaded DCG based holographic elements for spectrum-splitting PV systems

    Science.gov (United States)

    Wu, Yuechen; Chrysler, Benjamin; Pelaez, Silvana Ayala; Kostuk, Raymond K.

    2017-09-01

    In this work, the technique of designing and optimizing broadband volume transmission holograms using dichromate gelatin (DCG) is summarized for solar spectrum-splitting application. Spectrum splitting photovoltaic system uses a series of single bandgap PV cells that have different spectral conversion efficiency properties to more fully utilize the solar spectrum. In such a system, one or more high performance optical filters are usually required to split the solar spectrum and efficiently send them to the corresponding PV cells. An ideal spectral filter should have a rectangular shape with sharp transition wavelengths. DCG is a near ideal holographic material for solar applications as it can achieve high refractive index modulation, low absorption and scattering properties and long-term stability to solar exposure after sealing. In this research, a methodology of designing and modeling a transmission DCG hologram using coupled wave analysis for different PV bandgap combinations is described. To achieve a broad diffraction bandwidth and sharp cut-off wavelength, a cascaded structure of multiple thick holograms is described. A search algorithm is also developed to optimize both single and two-layer cascaded holographic spectrum splitters for the best bandgap combinations of two- and three-junction SSPV systems illuminated under the AM1.5 solar spectrum. The power conversion efficiencies of the optimized systems under the AM1.5 solar spectrum are then calculated using the detailed balance method, and shows an improvement compared with tandem structure.

  8. EFFECT OF HYDRAULIC AND GEOMETRICAL PROPERTIES ON STEPPED CASCADE AERATION SYSTEM

    OpenAIRE

    VEDHACHALAM RATHINAKUMAR; GOVINDASAMY DHINAKARAN; CONETY RAVI SURIBABU

    2017-01-01

    Stepped cascade aeration system is commonly used to aerate the water and wastewater to increase the dissolved oxygen during pre and post treatment process. In the present research, experiments were conducted to evaluate the performance of a rectangular Cascade Aeration System with varying flow rates, risers and tread by maintaining constant width of the channel using water collected from reverse osmosis plant. The experiments were carried out with four different risers such as 0.15 m, 0.18 m,...

  9. Investigation of cascadability of add-drop multiplexers in OTDM systems

    DEFF Research Database (Denmark)

    Jepsen, Kim Stokholm; Poulsen, Henrik Nørskov; Clausen, Anders

    1998-01-01

    The influence of coherent cross-talk on the cascadability of add-drop multiplexers in optical time division multiplexing (OTDM) systems is analysed theoretically using moment generating functions. Calculations are validated by experiments......The influence of coherent cross-talk on the cascadability of add-drop multiplexers in optical time division multiplexing (OTDM) systems is analysed theoretically using moment generating functions. Calculations are validated by experiments...

  10. CasCADe: A Novel 4D Visualization System for Virtual Construction Planning.

    Science.gov (United States)

    Ivson, Paulo; Nascimento, Daniel; Celes, Waldemar; Barbosa, Simone Dj

    2018-01-01

    Building Information Modeling (BIM) provides an integrated 3D environment to manage large-scale engineering projects. The Architecture, Engineering and Construction (AEC) industry explores 4D visualizations over these datasets for virtual construction planning. However, existing solutions lack adequate visual mechanisms to inspect the underlying schedule and make inconsistencies readily apparent. The goal of this paper is to apply best practices of information visualization to improve 4D analysis of construction plans. We first present a review of previous work that identifies common use cases and limitations. We then consulted with AEC professionals to specify the main design requirements for such applications. These guided the development of CasCADe, a novel 4D visualization system where task sequencing and spatio-temporal simultaneity are immediately apparent. This unique framework enables the combination of diverse analytical features to create an information-rich analysis environment. We also describe how engineering collaborators used CasCADe to review the real-world construction plans of an Oil & Gas process plant. The system made evident schedule uncertainties, identified work-space conflicts and helped analyze other constructability issues. The results and contributions of this paper suggest new avenues for future research in information visualization for the AEC industry.

  11. Adaptive control of systems in cascade with saturation

    Science.gov (United States)

    Kannan, Suresh K.

    This thesis extends the use of neural-network-based model reference adaptive control to systems that occur as cascades. In general, these systems are not feedback linearizable. The approach taken is that of approximate feedback linearization of upper subsystems whilst treating the lower-subsystem states as virtual actuators. Similarly, lower-subsystems are also feedback linearized. Typically, approximate inverses are used for linearization purposes. Model error arising from the use of an approximate inverse is minimized using a neural-network as an adaptive element. Incorrect adaptation due to (virtual) actuator saturation and dynamics is avoided using the Pseudocontrol Hedging method. Using linear approximate inverses and linear reference models generally result in large desired pseudocontrol for large external commands. Even if the provided external command is feasible (null-controllable), there is no guarantee that the reference model trajectory is feasible. In order to mitigate this, nonlinear reference models based on nested-saturation methods are used to constrain the evolution of the reference model and thus the plant states. The method presented in this thesis lends itself to the inner-outer loop control of air vehicles, where the inner-loop controls attitude dynamics and the outer-loop controls the translational dynamics of the vehicle. The outer-loop treats the closed loop attitude dynamics as an actuator. Adaptation to uncertainty in the attitude, as well as the translational dynamics, is introduced, thus minimizing the effects of model error in all six degrees of freedom and leading to more accurate position tracking. A pole-placement approach is used to choose compensator gains for the tracking error dynamics. This alleviates timescale separation requirements, allowing the outer loop bandwidth to be closer to that of the inner loop, thus increasing position tracking performance. A poor model of the attitude dynamics and a basic kinematics model is

  12. Emergency Load Shedding Strategy Based on Sensitivity Analysis of Relay Operation Margin against Cascading Events

    DEFF Research Database (Denmark)

    Liu, Zhou; Chen, Zhe; Sun, Haishun Sun

    2012-01-01

    In order to prevent long term voltage instability and induced cascading events, a load shedding strategy based on the sensitivity of relay operation margin to load powers is discussed and proposed in this paper. The operation margin of critical impedance backup relay is defined to identify the ru...... into account to compensate load shedding amount calculation. And the multi-agent technology is applied for the whole strategy implementation. A test system is built in real time digital simulator (RTDS) and has demonstrated the effectiveness of the proposed strategy.......In order to prevent long term voltage instability and induced cascading events, a load shedding strategy based on the sensitivity of relay operation margin to load powers is discussed and proposed in this paper. The operation margin of critical impedance backup relay is defined to identify...... the runtime emergent states of related system component. Based on sensitivity analysis between the relay operation margin and power system state variables, an optimal load shedding strategy is applied to adjust the emergent states timely before the unwanted relay operation. Load dynamics is also taken...

  13. Analysis and improvement of face detection based on surf cascade

    Science.gov (United States)

    Hu, Siquan; Zhang, Caihong; Liu, Lei

    2017-08-01

    This paper aims to study limitations of the commonly employed boosting cascade framework. We focus on the factors like data, feature, weak classifier and stages. A set of novel experiments were done to show the relationship. The model contains three key points: SURF feature, weak classifier based on logistic regression and AUC-based cascade learning algorithm. This paper adds cross validation in logistic regression creatively which improves accuracy and speeds up convergence greatly. Eventually only five stages and about 100 weak classifiers are needed. The frontal face detector improves reject rate to 99% for the first three stages, decreases number of false positive greatly and achieves comparable performance among non-CNN techniques on FDDB dataset.

  14. Placement of Synchronized Measurements for Power System Observability during Cascaded Outages

    Science.gov (United States)

    Thirugnanasambandam, Venkatesh; Jain, Trapti

    2017-11-01

    Cascaded outages often result in power system islanding followed by a blackout and therefore considered as a severe disturbance. Maintaining the observability of each island may help in taking proper control actions to preserve the stability of individual islands thus, averting system collapse. With this intent, a strategy for placement of synchronized measurements, which can be obtained from phasor measurement units (PMU), has been proposed in this paper to keep the system observable during cascaded outages also. Since, all the cascaded failures may not lead to islanding situations, therefore, failures leading to islanding as well as non-islanding situations have been considered. A topology based algorithm has been developed to identify the islanding/non-islanding condition created by a particular cascaded event. Additional contingencies such as single line loss and single PMU failure have also been considered after the occurrence of cascaded events. The proposed method is further extended to incorporate the measurement redundancy, which is desirable for a reliable state estimation. The proposed scheme is tested on IEEE 14-bus, IEEE 30-bus and a practical Indian 246-bus networks. The numerical results ensure the observability of the power system under system intact as well as during cascaded islanding and non-islanding disturbances.

  15. Aerodynamic analysis of a supersonic cascade vibrating in a complex mode

    Science.gov (United States)

    Caruthers, J. E.; Riffel, R. E.

    1980-01-01

    An analysis is presented which has been used to predict the unsteady aerodynamic behavior of a finite supersonic cascade of airfoils forced in harmonic oscillation with airfoil-to-airfoil variations in amplitude. Theoretical predictions are compared with some recent experimental results at a reduced frequency representative of actual fan or compressor flutter cases. The similarity of the experimental situation in the finite cascade to the flutter of a severely mistuned rotor is noted.

  16. Rate theory modeling of defect evolution under cascade damage conditions: the influence of vacancy-type cascade remnants and application to the defect production characterization by microstructural analysis

    International Nuclear Information System (INIS)

    Katoh, Yutai; Muroga, Takeo; Kohyama, Akira; Stoller, R.E.; Namba, Chusei; Motojima, Osamu.

    1995-11-01

    Recent computational and experimental studies have confirmed that high energy cascades produce clustered defects of both vacancy- and interstitial-types as well as isolated point defects. However, the production probability, configuration, stability and other characteristics of the cascade clusters are not well understood in spite of the fact that clustered defect production would substantially affect the irradiation-induced microstructures and the consequent property changes in a certain range of temperatures and displacement rates. In this work, a model of point defect and cluster evolution in irradiated materials under cascade damage conditions was developed by combining the conventional reaction rate theory and the results from the latest molecular dynamics simulation studies. This paper provides a description of the model and a model-based fundamental investigation of the influence of configuration, production efficiency and the initial size distribution of cascade-produced vacancy clusters. In addition, using the model, issues on characterizing cascade-induced defect production by microstructural analysis will be discussed. In particular, the determination of cascade vacancy cluster configuration, surviving defect production efficiency and cascade-interaction volume is attempted by analyzing the temperature dependence of swelling rate and loop growth rate in austenitic steels and model alloys. (author)

  17. The performance of a temperature cascaded cogeneration system producing steam, cooling and dehumidification

    KAUST Repository

    Myat, Aung

    2013-02-01

    This paper discusses the performance of a temperature-cascaded cogeneration plant (TCCP), equipped with an efficient waste heat recovery system. The TCCP, also called a cogeneration system, produces four types of useful energy-namely, (i) electricity, (ii) steam, (iii) cooling and (iv) dehumidification-by utilizing single fuel source. The TCCP comprises a Capstone C-30 micro-turbine that generates nominal capacity of 26 kW of electricity, a compact and efficient waste heat recovery system and a host of waste-heat-activated devices, namely (i) a steam generator, (ii) an absorption chiller, (iii) an adsorption chiller and (iv) a multi-bed desiccant dehumidifier. The performance analysis was conducted under different operation conditions such as different exhaust gas temperatures. It was observed that energy utilization factor could be as high as 70% while fuel energy saving ratio was found to be 28%. © 2013 Desalination Publications.

  18. Modelling of the Blood Coagulation Cascade in an In Vitro Flow System

    DEFF Research Database (Denmark)

    Andersen, Nina Marianne; Sørensen, Mads Peter; Efendiev, Messoud A.

    2010-01-01

    We derive a mathematical model of a part of the blood coagulation cascade set up in a perfusion experiment. Our purpose is to simulate the influence of blood flow and diffusion on the blood coagulation pathway. The resulting model consists of a system of partial differential equations taking...... and flow equations, which guarantee non negative concentrations at all times. The criteria is applied to the model of the blood coagulation cascade....

  19. Closed Loop Fuzzy Logic Controlled PV Based Cascaded Boost Five-Level Inverter System

    Science.gov (United States)

    Revana, Guruswamy; Kota, Venkata Reddy

    2018-04-01

    Recent developments in intelligent control methods and power electronics have produced PV based DC to AC converters related to AC drives. Cascaded boost converter and inverter find their way in interconnecting PV and Induction Motor. This paper deals with digital simulation and implementation of closed loop controlled five-level inverter based Photo-Voltaic (PV) system. The objective of this work is to reduce the harmonics using Multi Level Inverter based system. The DC output from the PV panel is boosted using cascaded-boost-converters. The DC output of these cascaded boost converters is applied to the bridges of the cascaded inverter. The AC output voltage is obtained by the series cascading of the output voltage of the two inverters. The investigations are done with Induction motor load. Cascaded boost-converter is proposed in the present work to produce the required DC Voltage at the input of the bridge inverter. A simple FLC is applied to CBFLIIM system. The FLC is proposed to reduce the steady state error. The simulation results are compared with the hardware results. The results of the comparison are made to show the improvement in dynamic response in terms of settling time and steady state error. Design procedure and control strategy are presented in detail.

  20. Closed Loop Fuzzy Logic Controlled PV Based Cascaded Boost Five-Level Inverter System

    Science.gov (United States)

    Revana, Guruswamy; Kota, Venkata Reddy

    2017-12-01

    Recent developments in intelligent control methods and power electronics have produced PV based DC to AC converters related to AC drives. Cascaded boost converter and inverter find their way in interconnecting PV and Induction Motor. This paper deals with digital simulation and implementation of closed loop controlled five-level inverter based Photo-Voltaic (PV) system. The objective of this work is to reduce the harmonics using Multi Level Inverter based system. The DC output from the PV panel is boosted using cascaded-boost-converters. The DC output of these cascaded boost converters is applied to the bridges of the cascaded inverter. The AC output voltage is obtained by the series cascading of the output voltage of the two inverters. The investigations are done with Induction motor load. Cascaded boost-converter is proposed in the present work to produce the required DC Voltage at the input of the bridge inverter. A simple FLC is applied to CBFLIIM system. The FLC is proposed to reduce the steady state error. The simulation results are compared with the hardware results. The results of the comparison are made to show the improvement in dynamic response in terms of settling time and steady state error. Design procedure and control strategy are presented in detail.

  1. Emotional intelligence: an integrative meta-analysis and cascading model.

    Science.gov (United States)

    Joseph, Dana L; Newman, Daniel A

    2010-01-01

    Research and valid practice in emotional intelligence (EI) have been impeded by lack of theoretical clarity regarding (a) the relative roles of emotion perception, emotion understanding, and emotion regulation facets in explaining job performance; (b) conceptual redundancy of EI with cognitive intelligence and Big Five personality; and (c) application of the EI label to 2 distinct sets of constructs (i.e., ability-based EI and mixed-based EI). In the current article, the authors propose and then test a theoretical model that integrates these factors. They specify a progressive (cascading) pattern among ability-based EI facets, in which emotion perception must causally precede emotion understanding, which in turn precedes conscious emotion regulation and job performance. The sequential elements in this progressive model are believed to selectively reflect Conscientiousness, cognitive ability, and Neuroticism, respectively. "Mixed-based" measures of EI are expected to explain variance in job performance beyond cognitive ability and personality. The cascading model of EI is empirically confirmed via meta-analytic data, although relationships between ability-based EI and job performance are shown to be inconsistent (i.e., EI positively predicts performance for high emotional labor jobs and negatively predicts performance for low emotional labor jobs). Gender and race differences in EI are also meta-analyzed. Implications for linking the EI fad in personnel selection to established psychological theory are discussed. Copyright 2009 APA, all rights reserved.

  2. A Cascading Storm-Flood-Landslide Guidance System: Development and Application in China

    Science.gov (United States)

    Zeng, Ziyue; Tang, Guoqiang; Long, Di; Ma, Meihong; Hong, Yang

    2016-04-01

    Flash floods and landslides, triggered by storms, often interact and cause cascading effects on human lives and property. Satellite remote sensing data has significant potential use in analysis of these natural hazards. As one of the regions continuously affected by severe flash floods and landslides, Yunnan Province, located in Southwest China, has a complex mountainous hydrometeorology and suffers from frequent heavy rainfalls from May through to late September. Taking Yunnan as a test-bed, this study proposed a Cascading Storm-Flood-Landslide Guidance System to progressively analysis and evaluate the risk of the multi-hazards based on multisource satellite remote sensing data. First, three standardized rainfall amounts (average daily amount in flood seasons, maximum 1h and maximum 6h amount) from the products of Topical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA) were used as rainfall indicators to derive the StorM Hazard Index (SMHI). In this process, an integrated approach of the Analytic Hierarchy Process (AHP) and the Information-Entropy theory was adopted to determine the weight of each indicator. Then, land cover and vegetation cover data from the Moderate Resolution Imaging Spectroradiometer (MODIS) products, soil type from the Harmonized World Soil Database (HWSD) soil map, and slope from the Shuttle Radar Topography Mission (SRTM) data were add as semi-static geo-topographical indicators to derive the Flash Flood Hazard Index (FFHI). Furthermore, three more relevant landslide-controlling indicators, including elevation, slope angle and soil text were involved to derive the LandSlide Hazard Index (LSHI). Further inclusion of GDP, population and prevention measures as vulnerability indicators enabled to consecutively predict the risk of storm to flash flood and landslide, respectively. Consequently, the spatial patterns of the hazard indices show that the southeast of Yunnan has more possibility to encounter with storms

  3. Joint state and parameter estimation for a class of cascade systems: Application to a hemodynamic model

    KAUST Repository

    Zayane, Chadia

    2014-06-01

    In this paper, we address a special case of state and parameter estimation, where the system can be put on a cascade form allowing to estimate the state components and the set of unknown parameters separately. Inspired by the nonlinear Balloon hemodynamic model for functional Magnetic Resonance Imaging problem, we propose a hierarchical approach. The system is divided into two subsystems in cascade. The state and input are first estimated from a noisy measured signal using an adaptive observer. The obtained input is then used to estimate the parameters of a linear system using the modulating functions method. Some numerical results are presented to illustrate the efficiency of the proposed method.

  4. Modeling and Analysis of the Common Mode Voltage in a Cascaded H-Bridge Electronic Power Transformer

    Directory of Open Access Journals (Sweden)

    Yun Yang

    2017-09-01

    Full Text Available Electronic power transformers (EPTs have been identified as emerging intelligent electronic devices in the future smart grid, e.g., the Energy Internet, especially in the application of renewable energy conversion and management. Considering that the EPT is directly connected to the medium-voltage grid, e.g., a10 kV distribution system, and its cascaded H-bridges structure, the common mode voltage (CMV issue will be more complex and severe. The CMV will threaten the insulation of the entire EPT device and even produce common mode current. This paper investigates the generated mechanism and characteristics of the CMV in a cascaded H-bridge EPT (CHB-EPT under both balanced and fault grid conditions. First, the CHB-EPT system is introduced. Then, a three-phase simplified circuit model of the high-voltage side of the EPT system is presented. Combined with a unipolar modulation strategy and carrier phase shifting technology by rigorous mathematical analysis and derivation, the EPT internal CMV and its characteristics are obtained. Moreover, the influence of the sinusoidal pulse width modulation dead time is considered and discussed based on analytical calculation. Finally, the simulation results are provided to verify the validity of the aforementioned model and the analysis results. The proposed theoretical analysis method is also suitable for other similar cascaded converters and can provide a useful theoretical guide for structural design and power density optimization.

  5. Quantitative analysis of volatile organic compounds using ion mobility spectra and cascade correlation neural networks

    Science.gov (United States)

    Harrington, Peter DEB.; Zheng, Peng

    1995-01-01

    Ion Mobility Spectrometry (IMS) is a powerful technique for trace organic analysis in the gas phase. Quantitative measurements are difficult, because IMS has a limited linear range. Factors that may affect the instrument response are pressure, temperature, and humidity. Nonlinear calibration methods, such as neural networks, may be ideally suited for IMS. Neural networks have the capability of modeling complex systems. Many neural networks suffer from long training times and overfitting. Cascade correlation neural networks train at very fast rates. They also build their own topology, that is a number of layers and number of units in each layer. By controlling the decay parameter in training neural networks, reproducible and general models may be obtained.

  6. Exergoeconomic and environmental analyses of CO2/NH3 cascade refrigeration systems equipped with different types of flash tank intercoolers

    International Nuclear Information System (INIS)

    Mosaffa, A.H.; Farshi, L. Garousi; Infante Ferreira, C.A.; Rosen, M.A.

    2016-01-01

    Highlights: • CO 2 /NH 3 cascade refrigeration cycles with flash intercoolers are investigated. • Exergoeconomic factors of components are determined to assess their relative significances. • An environmental analysis is applied to determine the penalty cost of GHG emission. • The effects of operating parameters on COP, exergy efficiency and total cost rate are investigated. • An optimization is applied based on the maximum COP and the minimum total cost rate. - Abstract: Exergoeconomic and environmental analyses are presented for two CO 2 /NH 3 cascade refrigeration systems equipped with (1) two flash tanks and (2) a flash tank along with a flash intercooler with indirect subcooler. A comparative study is performed for the proposed systems, and optimal values of operating parameters of the system are determined that maximize the coefficient of performance (COP) and exergy efficiency and minimize the total annual cost. The operating parameters considered include condensing temperatures of NH 3 in the condenser and CO 2 in the cascade heat exchanger, the evaporating temperature of CO 2 in the evaporator, the temperature difference in the cascade heat exchanger, the intermediate pressure of the flash tank in the CO 2 low-temperature circuit, the mass flow rate ratio in the flash intercooler and the degree of superheating of the CO 2 at the evaporator outlet. The total annual cost includes the capital, operating and maintenance costs and the penalty cost of GHG emission. The results show that, the total annual cost rate for system 1 is 11.2% and 11.9% lower than that for system 2 referring to thermodynamic and economic optimizations, respectively. For thermodynamic and cost optimal design condition the COP and exergy efficiency of both systems are almost the same. Finally, in order to obtain the best balance between exergy destruction cost and capital cost, the exergoeconomic factor is defined for each component of proposed systems, for cases in which the

  7. Experimental study of a cascade solar still coupled with a humidification–dehumidification system

    International Nuclear Information System (INIS)

    Farshchi Tabrizi, Farshad; Khosravi, Meisam; Shirzaei Sani, Iman

    2016-01-01

    Graphical abstract: In this study, coupling of a cascade solar still with a humidification–dehumidification system investigated experimentally. In addition, the effects of different operating conditions and configurations on thermal performance and productivity of the under investigation solar system were studied. - Highlights: • We investigate coupling of a cascade solar still with a humidification–dehumidification system. • The effects of different operating conditions on thermal performance were studied. • Temperature and flow rate of feed water as well as air process flow rate had undeniable effects on the productivity. • Coupling several CSS systems with just one HD system to maximize the productivity. • Enhancing daily productivity of coupling system from 28% to 141% for 40–150 ml/min flow rates, respectively. - Abstract: In this study, coupling of a cascade solar still with a humidification–dehumidification system was investigated experimentally under the climatological conditions of Zahedan (Latitude: 29.49, Longitude: 60.87), Iran. The inclined solar stills produce distillated and hot water simultaneously. In addition, the effects of different operating conditions and configurations on thermal performance and productivity of the solar system were studied. The effect of feed water and air flow rates on the daily productivity of HD system in different conditions such as feed water temperature has been investigated. The daily productivity of cascade solar still with and without HD system at different flow rates is investigated. Moreover, the end result of assembling the HD system with a cascade solar still was studied. The daily productivity of the system increases from 28% to 141% in the presence of humidification–dehumidification system. It also improves the thermal efficiency from 9% to 20% after using 40–150 ml/min of flow rate, respectively. The maximum productivity and efficiency were 5.4 kg/m 2 day and 39% for minimum flow rate.

  8. A Concurrent Implementation of the Cascade-Correlation Algorithm, Using the Time Warp Operating System

    Science.gov (United States)

    Springer, P.

    1993-01-01

    This paper discusses the method in which the Cascade-Correlation algorithm was parallelized in such a way that it could be run using the Time Warp Operating System (TWOS). TWOS is a special purpose operating system designed to run parellel discrete event simulations with maximum efficiency on parallel or distributed computers.

  9. Multi Agent System Based Process Control in Wide Area Protection against Cascading Events

    DEFF Research Database (Denmark)

    Liu, Zhou; Chen, Zhe; Sun, Haishun

    2013-01-01

    In order to prevent long term voltage instability induced cascading events; a multi agent system (MAS) based wide area protection strategy is proposed in this paper. Due to some unexpected failures of control strategy execution or the consequent unexpected disturbance, the power system will face...... the effectiveness of the improved MAS based protection strategy....

  10. A new cascade method for studying isotope effect in chemical exchange system without valance change

    International Nuclear Information System (INIS)

    Wen Xiaoning; Luo Wenzong

    1987-01-01

    A new cascade method for studying isotope effect in chemical exchange system without valance change is developed and described. This method is simple to use and consumes less extractant as compared with the commonly used Woodward method. It is also convenient for unstable systems

  11. Cascade Controller Including Back-stepping for Hydraulic-Mechanical Systems

    DEFF Research Database (Denmark)

    Choux, Martin; Hovland, Geir; Blanke, Mogens

    2012-01-01

    Development of a cascade controller structure including adaptive backstepping for a nonlinear hydraulic-mechanical system is considered in this paper where a dynamic friction (LuGre) model is included to obtain the necessary accuracy. The paper compares the performance of two variants of an adapt......Development of a cascade controller structure including adaptive backstepping for a nonlinear hydraulic-mechanical system is considered in this paper where a dynamic friction (LuGre) model is included to obtain the necessary accuracy. The paper compares the performance of two variants...... of an adaptive backstepping tracking controller with earlier results. The new control architecture is analysed and enhanced tracking performance is demonstrated when including the extended friction model. The complexity of the backstepping procedure is significantly reduced due to the cascade structure. Hence......, the proposed control structure is better suited to real-time implementation. © 2012 IFAC....

  12. Comprehensive Analysis of LCL Filter Interfaced Cascaded H-Bridge Multilevel Inverter-Based DSTATCOM

    Directory of Open Access Journals (Sweden)

    Ravikant Pandey

    2017-03-01

    Full Text Available Three-phase two-level voltage source converters are used for distribution static compensator (DSTATCOM applications and can be replaced by a multilevel inverter. In this paper, an LCL filter interfaced cascaded H-bridge multilevel inverter-based (CHBMLI DSTATCOM is simulated and its performance is analyzed considering the system parameters. The analysis considers factors including the switching frequency, modulation index, and filter parameters of a DSTATCOM system. The LCL filter design and analysis for the low switching frequency operation of CHBMLI is proposed in this paper. Phase shift pulse-width modulation is used for the generation of switching signals. The reference current is generated using synchronous reference frame theory (SRFT for reactive power and harmonic compensations. The simulation model of the CHBMLI-based DSTATCOM system is developed in MATLAB Simulink. The results are demonstrated for a linear/non-linear load under unbalanced conditions, considering the voltage sag and swell in the system due to a disturbance in the load.

  13. Discriminating cascading processes in nonlinear optics: A QED analysis based on their molecular and geometric origin

    Science.gov (United States)

    Bennett, Kochise; Chernyak, Vladimir Y.; Mukamel, Shaul

    2017-03-01

    The nonlinear optical response of a system of molecules often contains contributions whereby the products of lower-order processes in two separate molecules give signals that appear on top of a genuine direct higher-order process with a single molecule. These many-body contributions are known as cascading and complicate the interpretation of multidimensional stimulated Raman and other nonlinear signals. In a quantum electrodynamic treatment, these cascading processes arise from second-order expansion in the molecular coupling to vacuum modes of the radiation field, i.e., single-photon exchange between molecules, which also gives rise to other collective effects. We predict the relative phase of the direct and cascading nonlinear signals and its dependence on the microscopic dynamics as well as the sample geometry. This phase may be used to identify experimental conditions for distinguishing the direct and cascading signals by their phase. Higher-order cascading processes involving the exchange of several photons between more than two molecules are discussed.

  14. Characteristics of multi-stage AGMD-DCMD cascade system for oxygen isotope production

    International Nuclear Information System (INIS)

    Kim, Jae Woo; Choi, Hwa Rim; Chang, Dae Sik; Kim, Taek Soo; Lim, Gwon; Jeong, Do Young

    2005-01-01

    Membrane distillation (MD) appears to be useful for the separation of the light isotopes such as oxygen and hydrogen isotopes contained in water, because membrane permeation units are compact and simple, and more importantly its energy consumption is low compared to conventional water fractional distillation.1-4 Permeation fluxes and the degree of oxygen isotope separation of AGMD (Air Gap Membrane Distillation) and VEMD (Vacuum Enhanced Membrane Distillation) processes were measured by using the hot water feed. Even though VEMD shows slightly higher isotopic separation degree with higher permeation flux, it is very difficult to apply VEMD to multi-stage cascade system. Since local oxygen isotope separation coefficient for a single membrane unit is low, multi-stage membrane cascade system is required to increase isotopic concentration further in product. Although AGMD is suitable for constructing the membrane cascading system, permeation flux for AGMD is still too low to apply to the isotope production system. In this investigation, we increased permeation flux of AGMD using AGMD-DCMD (Direct Contact Membrane Distillation) combined process. Permeation flux and degree of isotope separation of AGMD-DCMD combined process were measured by using 10 stages cascade system

  15. Integration of VICbus, FDL, SCI and Ethernet in the CERN CASCADE data acquisition system

    CERN Document Server

    Petersen, J; Bogaerts, A; Burckhart, Doris; Divià, R; Ingebritsen, L; Joos, M; Liebhart, M; Niewold, J; Parkman, C; Perrin, Yves; Thiercelin, B; Tremblet, L J; Vascotto, Alessandro; Werner, P

    1995-01-01

    Cascade is a multi-processor real-time data-acquisition system for HEP experiments developed at CERN by the ECP-DS group. Configurations supported today include VMEbus processors running OS-9 and UNIX workstations. The CASCADE data acquisition processes, called stages communicate via links, at present VICbus between VME crates and Ethernet between VMEbus processors and workstations. Work is in progress to introduce new inter-stage links based on the Fast Data Link between VME crates and on SCI for data exchange between SUN stations. The paper gives a short description of the architecture of CASCADE with emphasis on the link aspects. The implementation and current status of the inter-stage links based on VICbus, Ethernet, FDI, and SCI will be described and results on the performances presented.

  16. ARRA: Reconfiguring Power Systems to Minimize Cascading Failures - Models and Algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Dobson, Ian [Iowa State University; Hiskens, Ian [Unversity of Michigan; Linderoth, Jeffrey [University of Wisconsin-Madison; Wright, Stephen [University of Wisconsin-Madison

    2013-12-16

    Building on models of electrical power systems, and on powerful mathematical techniques including optimization, model predictive control, and simluation, this project investigated important issues related to the stable operation of power grids. A topic of particular focus was cascading failures of the power grid: simulation, quantification, mitigation, and control. We also analyzed the vulnerability of networks to component failures, and the design of networks that are responsive to and robust to such failures. Numerous other related topics were investigated, including energy hubs and cascading stall of induction machines

  17. Multi-species trace gas analysis with dual-wavelength quantum cascade laser

    Science.gov (United States)

    Jágerská, Jana; Tuzson, Béla; Looser, Herbert; Jouy, Pierre; Hugi, Andreas; Mangold, Markus; Soltic, Patrik; Faist, Jérôme; Emmenegger, Lukas

    2015-04-01

    Simultaneous detection of multiple gas species using mid-IR laser spectroscopy is highly appealing for a large variety of applications ranging from air quality monitoring, medical breath analysis to industrial process control. However, state-of-the-art distributed-feedback (DFB) mid-IR lasers are usually tunable only within a narrow spectral range, which generally leads to one-laser-one-compound measurement strategy. Thus, multi-species detection involves several lasers and elaborate beam combining solutions [1]. This makes them bulky, costly, and highly sensitive to optical alignment, which limits their field deployment. In this paper, we explore an alternative measurement concept based on a dual-wavelength quantum cascade laser (DW-QCL) [2]. Such a laser can emit at two spectrally distinct wavelengths using a succession of two DFB gratings with different periodicities and a common waveguide to produce one output beam. The laser design was optimized for NOx measurements and correspondingly emits single-mode at 5.26 and 6.25 μm. Electrical separation of the respective laser sections makes it possible to address each wavelength independently. Thereby, it is possible to detect NO and NO2 species with one laser using the same optical path, without any beam combining optics, i.e. in a compact and cost-efficient single-path optical setup. Operated in a time-division multiplexed mode, the spectrometer reaches detection limits at 100 s averaging of 0.5 and 1.5 ppb for NO2 and NO, respectively. The performance of the system was validated against the well-established chemiluminescence detection while measuring the NOx emissions on an automotive test-bench, as well as monitoring the pollution at a suburban site. [1] B. Tuzson, K. Zeyer, M. Steinbacher, J. B. McManus, D. D. Nelson, M. S. Zahniser, and L. Emmenegger, 'Selective measurements of NO, NO2 and NOy in the free troposphere using quantum cascade laser spectroscopy,' Atmospheric Measurement Techniques 6, 927-936 (2013

  18. Application of Cascade Refrigeration System with Mixing Refrigerant in Cold Air Cutting

    Science.gov (United States)

    Yang, Y.; Tong, M. W.; Yang, G.; Wang, X. P.

    In the mechanical cutting process, the replacement of traditional cutting solution with cold air can avoid the pollution of environment. In order to high efficient the refrigerating device and flexible adjust the temperature of cold air, it is necessary to use cascade refrigeration system to supply cool quantity for the compressed air. The introduction of a two-component non-azeotropic mixing refrigerant into the cryogenic part of the cascade system, can effectively solve the problems of the system working at too high pressure and the volume expanding of refrigerant in case of the cascade refrigeration sets closed down. However, the filling ratio of mixing refrigerants impact on the relationships among the closing down pressure, refrigerating output and refrigerating efficiency. On the basis of computing and experiment, the optimal mixing ratio of refrigerant R22/R13 and a low temperature of -60° were obtained in this study. A cold air injecting device possessing high efficiency in energy saving has also been designed and manufactured. The cold air, generated from this cascade system and employed in a cutting process, takes good comprehensive effects on machining and cutting.

  19. Multicounter system for high-multiplicity γ-ray cascades: performances and first experiment at the Laboratorio Nazionale del Sud

    International Nuclear Information System (INIS)

    Del Zoppo, A.; Agodi, C.; Bellia, G.; Calabretta, L.; Maiolino, C.; Migneco, E.; Piattelli, P.

    1986-01-01

    A multicounter system for high-multiplicity γ-ray cascade measurements has been designed. The detection system, consisting of 12NaI(Tl) scintillation counters, is described. Tests concerning high-multiplicity cascade detection probability and cross-talk are discussed. Performances of the multiplicity filter in investigations on nuclei at very high spin produced in heavy-ion fusion are presented

  20. Multicounter system for high-multiplicity. gamma. -ray cascades. Performances and first experiment at the Laboratorio Nazionale del Sud

    Energy Technology Data Exchange (ETDEWEB)

    Del Zoppo, A.; Agodi, C.; Bellia, G.; Calabretta, L.; Maiolino, C.; Migneco, E.; Piattelli, P.

    1986-02-21

    A multicounter system for high-multiplicity ..gamma..-ray cascade measurements has been designed. The detection system, consisting of 12 NaI(Tl) scintillation counters, is described. Tests concerning high-multiplicity cascade detection probability and cross-talk are discussed. Performances of the multiplicity filter in investigations on nuclei at very high spin produced in heavy-ion fusion are presented.

  1. Estimating Energy- and Eco-Balances for Continuous Bio-Ethanol Production Using a Blenke Cascade System

    OpenAIRE

    Ntihuga, Jean; Senn, Thomas; Gschwind, Peter; Kohlus, Reinhard

    2013-01-01

    Energy and environmental effects of wheat-based fuel, produced continuously by a Blenke cascade system, were assessed. Two scenarios: (1) no-co-products utilization scenario; and (2) co-products utilization scenario, were compared. A Life Cycle Assessment (LCA) model was used for analysis. The scope covered a cradle-to-gate inventory. The results from energy analysis showed, that wheat-based ethanol has a positive average net energy value (NEV), NEV = 3.35 MJ/kg ethanol with an average net en...

  2. Learning Cascading

    CERN Document Server

    Covert, Michael

    2015-01-01

    This book is intended for software developers, system architects and analysts, big data project managers, and data scientists who wish to deploy big data solutions using the Cascading framework. You must have a basic understanding of the big data paradigm and should be familiar with Java development techniques.

  3. Sediment Deposition Risk Analysis and PLSR Model Research for Cascade Reservoirs Upstream of the Yellow River

    Directory of Open Access Journals (Sweden)

    Jie Yang

    2015-01-01

    Full Text Available It is difficult to effectively identify and eliminate the multiple correlation influence among the independent factors by least-squares regression. Focusing on this insufficiency, the sediment deposition risk of cascade reservoirs and fitting model of sediment flux into the reservoir are studied. The partial least-squares regression (PLSR method is adopted for modeling analysis; the model fitting is organically combined with the non-model-style data content analysis, so as to realize the regression model, data structure simplification, and multiple correlations analysis among factors; meanwhile the accuracy of the model is ensured through cross validity check. The modeling analysis of sediment flux into the cascade reservoirs of Long-Liu section upstream of the Yellow River indicates that partial least-squares regression can effectively overcome the multiple correlation influence among factors, and the isolated factor variables have better ability to explain the physical cause of measured results.

  4. A Biocatalytic One-Pot Approach for the Preparation of Lignin Oligomers Using an Oxidase/Peroxidase Cascade Enzyme System

    NARCIS (Netherlands)

    Habib, Mohamed H. M.; Deuss, Peter J.; Loncar, Nikola; Trajkovic, Milos; Fraaije, Marco W.

    2017-01-01

    Synthetic lignin was prepared biocatalytically in a one-pot, two-step reaction using an oxidase/peroxidase cascade enzyme system. Using eugenol in combination with eugenol oxidase and a peroxidase, lignin-like material was produced. The cascade reaction takes advantage of the ability of the oxidase

  5. Critical System Cascading Collapse Assessment for Determining the Sensitive Transmission Lines and Severity of Total Loading Conditions

    Directory of Open Access Journals (Sweden)

    Nur Ashida Salim

    2013-01-01

    Full Text Available This paper presents a computationally accurate technique used to determine the estimated average probability of a system cascading collapse considering the effect of hidden failure on a protection system. This includes an accurate calculation of the probability of hidden failure as it will give significant effect on the results of the estimated average probability of system cascading collapse. The estimated average probability of a system cascading collapse is then used to determine the severe loading condition contributing to a higher risk of a system cascading collapse. This information is important because it will assist the utility to determine the maximum level of increase in the system loading condition before the occurrence of critical power system cascading collapse. Furthermore, the initial tripping of sensitive transmission line contributing to a critical system cascading collapse can also be determined by using the proposed method. Based on the results obtained from this study, it was found that selecting the accurate probability of hidden failure is very important as it will affect the estimated average probability of a system cascading collapse. Comparative study has been done with other techniques to verify the effectiveness of the proposed method used in the determination of sensitive transmission lines.

  6. Improved Dynamic Modeling of the Cascade Distillation Subsystem and Analysis of Factors Affecting Its Performance

    Science.gov (United States)

    Perry, Bruce A.; Anderson, Molly S.

    2015-01-01

    The Cascade Distillation Subsystem (CDS) is a rotary multistage distiller being developed to serve as the primary processor for wastewater recovery during long-duration space missions. The CDS could be integrated with a system similar to the International Space Station Water Processor Assembly to form a complete water recovery system for future missions. A preliminary chemical process simulation was previously developed using Aspen Custom Modeler® (ACM), but it could not simulate thermal startup and lacked detailed analysis of several key internal processes, including heat transfer between stages. This paper describes modifications to the ACM simulation of the CDS that improve its capabilities and the accuracy of its predictions. Notably, the modified version can be used to model thermal startup and predicts the total energy consumption of the CDS. The simulation has been validated for both NaC1 solution and pretreated urine feeds and no longer requires retuning when operating parameters change. The simulation was also used to predict how internal processes and operating conditions of the CDS affect its performance. In particular, it is shown that the coefficient of performance of the thermoelectric heat pump used to provide heating and cooling for the CDS is the largest factor in determining CDS efficiency. Intrastage heat transfer affects CDS performance indirectly through effects on the coefficient of performance.

  7. A Cascading Model Of An Active Magnetic Regenerator System

    DEFF Research Database (Denmark)

    Tahavori, M.; Filonenko, K.; Veje, C. T.

    2016-01-01

    In recent years, significant amounts of studies have been done on modeling and analysis of active magnetic regenerators (AMRs). Depending on the AMR geometry and the magnetocaloric material being modeled, the AMR may not be able to provide the required performance demanded by practical applicatio...

  8. Analysis of Multicarrier PWM techniques for Photovoltaic fed Cascaded H-Bridge Multilevel Inverter

    Directory of Open Access Journals (Sweden)

    VENKATRAMAN Thiyagarajan

    2017-05-01

    Full Text Available Recently multilevel inverter technology emerging as an important alternative in the field of high power, medium voltage energy control. The various topologies for multilevel inverters such as diode-clamped, flying capacitor and cascaded H-bridge have been proposed over the years. This paper analysis the performance of a single phase seven level cascaded H-bridge inverter for photovoltaic applications. The Phase Disposition PWM (PDPWM technique is used to generate gate signals. The performance is compared for both sinusoidal reference waveform and trapezoidal reference waveform. The analysis is carried out for different modulation index and different shading pattern of photovoltaic (PV array. The simulation is carried out using MATLAB/SIMULINK software.

  9. Theoretical and simulation analysis of the fiber optical parametric amplifier (FOPA) with cascaded structure

    Science.gov (United States)

    Gao, Jie; Cao, Yongsheng; Chen, Fushen; Sun, Bao; Hu, Zhefeng

    2012-02-01

    A novel scheme is proposed to obviously improve the amplified gain, gain flatness and bandwidth characteristics of FOPA by applying a cascaded fiber structure. The basic structure of the cascaded fiber optical parametric amplifier (CFOPA) is introduced. Then, the expression of signals pass gain characteristic is obtained by utilizing a set of coupled equations. The gain, bandwidth and gain flatness characteristics of the CFOPA with the different parameters of DCF, such as fiber length l/, dispersion slope dD//dλ, and so on, are theoretical analyzed and optimized. Furthermore, simulation analysis is applied to verify the theoretical results by using Optisystem 7.0 software. Although, there are a few deviations between the simulation and the theoretical results, the simulation results effectively demonstrate the validity and feasibility of the theoretical analysis.

  10. Applying Enzymatic Cascades for ISCPR in ω-transaminase Systems

    DEFF Research Database (Denmark)

    Janes, Kresimir; Woodley, John; Tufvesson, Pär

    steps. An important fact is also that different types of selectivity make biocatalysis an excellent tool for overcoming difficulties typically associated with organic synthesis. Regioselectivity of the biocatalysts offers potential process simplification compared to the organic synthesis routes......Filtration Membrane Reactor) as a viable process design option and charge analysis showed that ISPR is possible via ion exchange resins or electrodialysis. An ISPR example showed that process intensification could yield significant reductions in the required ω-transaminase activity improvement (up to five fold...

  11. Hydrogen sulphide in cardiovascular system: A cascade from interaction between sulphur atoms and signalling molecules.

    Science.gov (United States)

    Wang, Ming-Jie; Cai, Wen-Jie; Zhu, Yi-Chun

    2016-05-15

    As a gasotransmitter, hydrogen sulphide exerts its extensive physiological and pathophysiological effects in mammals. The interaction between sulphur atoms and signalling molecules forms a cascade that modulates cellular functions and homeostasis. In this review, we focus on the signalling mechanism underlying the effect of hydrogen sulphide in the cardiovascular system and metabolism as well as the biological relevance to human diseases. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Automatic Detection of Cervical Cancer Cells by a Two-Level Cascade Classification System

    Directory of Open Access Journals (Sweden)

    Jie Su

    2016-01-01

    Full Text Available We proposed a method for automatic detection of cervical cancer cells in images captured from thin liquid based cytology slides. We selected 20,000 cells in images derived from 120 different thin liquid based cytology slides, which include 5000 epithelial cells (normal 2500, abnormal 2500, lymphoid cells, neutrophils, and junk cells. We first proposed 28 features, including 20 morphologic features and 8 texture features, based on the characteristics of each cell type. We then used a two-level cascade integration system of two classifiers to classify the cervical cells into normal and abnormal epithelial cells. The results showed that the recognition rates for abnormal cervical epithelial cells were 92.7% and 93.2%, respectively, when C4.5 classifier or LR (LR: logical regression classifier was used individually; while the recognition rate was significantly higher (95.642% when our two-level cascade integrated classifier system was used. The false negative rate and false positive rate (both 1.44% of the proposed automatic two-level cascade classification system are also much lower than those of traditional Pap smear review.

  13. The performance investigation of a temperature cascaded cogeneration system equipped with adsorption desalination unit

    KAUST Repository

    Myat, Aung

    2013-02-01

    This paper presents the performance investigation of a temperature cascaded cogeneration plant, shortly in TCCP, equipped with an efficient waste heat recovery system. The TCCP or cogeneration system produces four types of useful energy namely (i) electricity, (ii) steam, (iii) cooling, and (iv) dehumidification and distilled water by utilizing single energy source. The TCCP comprises a Capstone C30 micro-turbine that generates nominal capacity of 26 kW of electricity, a compact and efficient waste heat recovery system and a host of waste heatactivated devices namely (i) a steam generator, (ii) an absorption chiller, (iii) an adsorption desalination system, and (iv) a multi-bed desiccant dehumidifier. The analysis is performed under different operation conditions such as heat source temperatures, flow rates of heat transfer fluids and chilled water inlet temperatures. The only single heat source for TCCP is obtained from exhaust gas of micro-turbine and it is channeled to a series of waste heat recovery heat exchangers to steam and hot water at different temperatures. Hot water produced by such a compact heat exchangers is the driving heat source to produce steam of 15 kg/h, cooling of 2 Rton, dehumidification of 2 Rton, and distilled water of 0.7 m3/day. A set of experiments, both part load and full load, of micro-turbine is conducted to examine the electricity generation and the exhaust gas temperature. It is observed that energy utilization factor could achieve as high as 70% while fuel energy saving ratio is found to be 28%. © 2013 Desalination Publications. All rights reserved.

  14. Estimating Energy- and Eco-Balances for Continuous Bio-Ethanol Production Using a Blenke Cascade System

    Directory of Open Access Journals (Sweden)

    Reinhard Kohlus

    2013-04-01

    Full Text Available Energy and environmental effects of wheat-based fuel, produced continuously by a Blenke cascade system, were assessed. Two scenarios: (1 no-co-products utilization scenario; and (2 co-products utilization scenario, were compared. A Life Cycle Assessment (LCA model was used for analysis. The scope covered a cradle-to-gate inventory. The results from energy analysis showed, that wheat-based ethanol has a positive average net energy value (NEV, NEV = 3.35 MJ/kg ethanol with an average net energy ratio (NER, NER = 1.14 MJ/MJ fossils for scenario 1, while for scenario 2, NEV = 20 MJ/kg ethanol with NER = 3.94 MJ/MJ fossils. The environmental performance analysis indicated that in scenario 1, the strongest contribution to environmental impacts was from the ethanol conversion stage; whereas in scenario 2, it was from wheat production stage. The use of a continuous fermentation system based on Blenke cascade is a promising technology that increases wheat based bio-ethanol’s energy benefits. In addition, the calculated parameters show the potential to significantly reduce emissions level.

  15. A methodology for cascade selection for co-product removal in the ω-transaminase system

    DEFF Research Database (Denmark)

    Janes, Kresimir; Gernaey, Krist; Tufvesson, Pär

    for choosing a feasible cascade system that will remove co-product to meet process requirements under process relevant conditions will be presented. Decisions are based on thermodynamic constraints, kinetics, selectivity, stability, pH change, cascade enzyme compatibility and downstream processing......Production of chiral amines using transaminases has indeed been proposed recently as an interesting alternative to conventional methods to help in the synthesis of many new pharmaceuticals. Two reaction strategies have been demonstrated: kinetic resolution and asymmetric synthesis. The latter...... pharmaceutical processes can only be achieved by selectively removing the product and/or co-product formed during the reaction (so called in-situ (co)product removal (IS(C)PR)). Several different alternative co-product removal strategies have been suggested, all of which have different impacts on the overall...

  16. Cascade effects on coalescence of segregation in two-phase systems

    International Nuclear Information System (INIS)

    Kiryukhin, N.M.; Sagalovich, V.V.; Slezov, V.V.

    1987-01-01

    The evolution of binary precipitations in ternary alloys has been theoretically investigated taking into account cascade fracture of precipitations. The equation for the growth of such particle rate is obtained. A set of equations for describing the behaviour of the precipitation ensemble is stated, analytical solutions for this system in different limiting cases at a late stage (coalescence stage) are obtained. It is shown that the function of second-phase particle distribution in size in the material considered trends to universal. The presence of cascade leads to displacement of region boundaries, where coalescence occurs. The theoretical results obtained allow to describe qualitatively a number of mechanisms of precipitation behaviour under radiation observed experimentally

  17. Blind I/Q imbalance and nonlinear ISI mitigation in Nyquist-SCM direct detection system with cascaded widely linear and Volterra equalizer

    Science.gov (United States)

    Liu, Na; Ju, Cheng

    2018-02-01

    Nyquist-SCM signal after fiber transmission, direct detection (DD), and analog down-conversion suffers from linear ISI, nonlinear ISI, and I/Q imbalance, simultaneously. Theoretical analysis based on widely linear (WL) and Volterra series is given to explain the relationship and interaction of these three interferences. A blind equalization algorithm, cascaded WL and Volterra equalizer, is designed to mitigate these three interferences. Furthermore, the feasibility of the proposed cascaded algorithm is experimentally demonstrated based on a 40-Gbps data rate 16-quadrature amplitude modulation (QAM) virtual single sideband (VSSB) Nyquist-SCM DD system over 100-km standard single mode fiber (SSMF) transmission. In addition, the performances of conventional strictly linear equalizer, WL equalizer, Volterra equalizer, and cascaded WL and Volterra equalizer are experimentally evaluated, respectively.

  18. Evaluation of Refrigerating and Air Conditioning Devices in Energy Cascade Systems under the Restriction of Carbon Dioxide Emissions

    Science.gov (United States)

    Shimazaki, Yoichi; Akisawa, Atsushi; Kashiwagi, Takao

    It is necessary to introduce energy cascade systems into the industrial sector in Japan to reduce carbon dioxide emissions. The aim of this study is to evaluate the refrigerating and air conditioning devices in cases of introducing both energy cascade systems and thermal recycling systems in industries located around urban areas. The authors have developed an energy cascade model based on linear programming so as to minimize the total system costs with carbon taxes. Five cases are investigated. Limitation of carbon dioxide emissions results in the enhancement of heat cascading, where high temperature heat is supplied for process heating while low temperature one is shifted to refrigeration. It was found that increasing the amount of garbage combustor waste heat can reduce electric power for the turbo refrigerator by promoting waste heat driven ammonia absorption refrigerator.

  19. Development of an Exploration-Class Cascade Distillation System: Flight Like Prototype Preliminary Design

    Science.gov (United States)

    Callahan, Michael R.; Sargusingh, Miriam J.

    2015-01-01

    The ability to recover and purify water through physiochemical processes is crucial for realizing long-term human space missions, including both planetary habitation and space travel. Because of their robust nature, distillation systems have been actively pursued as one of the technologies for water recovery. One such technology is the Cascade Distillation System (CDS) a multi-stage vacuum rotary distiller system designed to recover water in a microgravity environment. Its rotating cascading distiller operates similarly to the state of the art (SOA) vapor compressor distiller (VCD), but its control scheme and ancillary components are judged to be straightforward and simpler to implement into a successful design. Through the Advanced Exploration Systems (AES) Life Support Systems (LSS) Project, the NASA Johnson Space Center (JSC) in collaboration with Honeywell International is developing a second generation flight forward prototype (CDS 2.0). The key objectives for the CDS 2.0 design task is to provide a flight forward ground prototype that demonstrates improvements over the SOA system in the areas of increased reliability and robustness, and reduced mass, power and volume. It will also incorporate exploration-class automation. The products of this task are a preliminary flight system design and a high fidelity prototype of an exploration class CDS. These products will inform the design and development of the third generation CDS which is targeted for on-orbit DTO. This paper details the preliminary design of the CDS 2.0.

  20. The prevention of mother-to-child transmission of HIV cascade analysis tool: supporting health managers to improve facility-level service delivery.

    Science.gov (United States)

    Gimbel, Sarah; Voss, Joachim; Mercer, Mary Anne; Zierler, Brenda; Gloyd, Stephen; Coutinho, Maria de Joana; Floriano, Florencia; Cuembelo, Maria de Fatima; Einberg, Jennifer; Sherr, Kenneth

    2014-10-21

    The objective of the prevention of Mother-to-Child Transmission (pMTCT) cascade analysis tool is to provide frontline health managers at the facility level with the means to rapidly, independently and quantitatively track patient flows through the pMTCT cascade, and readily identify priority areas for clinic-level improvement interventions. Over a period of six months, five experienced maternal-child health managers and researchers iteratively adapted and tested this systems analysis tool for pMTCT services. They prioritized components of the pMTCT cascade for inclusion, disseminated multiple versions to 27 health managers and piloted it in five facilities. Process mapping techniques were used to chart PMTCT cascade steps in these five facilities, to document antenatal care attendance, HIV testing and counseling, provision of prophylactic anti-retrovirals, safe delivery, safe infant feeding, infant follow-up including HIV testing, and family planning, in order to obtain site-specific knowledge of service delivery. Seven pMTCT cascade steps were included in the Excel-based final tool. Prevalence calculations were incorporated as sub-headings under relevant steps. Cells not requiring data inputs were locked, wording was simplified and stepwise drop-offs and maximization functions were included at key steps along the cascade. While the drop off function allows health workers to rapidly assess how many patients were lost at each step, the maximization function details the additional people served if only one step improves to 100% capacity while others stay constant. Our experience suggests that adaptation of a cascade analysis tool for facility-level pMTCT services is feasible and appropriate as a starting point for discussions of where to implement improvement strategies. The resulting tool facilitates the engagement of frontline health workers and managers who fill out, interpret, apply the tool, and then follow up with quality improvement activities. Research on

  1. A study of temperature sensor location based on fractal analysis for cascade control schemes in tubular reactors

    DEFF Research Database (Denmark)

    Eduardo Ramirez-Castelan, Carlos; Moguel-Castañeda, Jazael; Puebla, Hector

    2016-01-01

    Temperature sensor location for cascade control schemes in tubular reactors is still an open research problem. Several studies have pointed out that most temperature sensitive zones along the length of the reactor are suitable to this end. In this work, we have studied the problem of sensor...... location in a cascade control configuration using fractal analysis of time series obtained by random forcing of the jacket rector. A benchmark dispersion axial model displaying different temperature profiles is used to illustrate our findings....

  2. EFFECT OF HYDRAULIC AND GEOMETRICAL PROPERTIES ON STEPPED CASCADE AERATION SYSTEM

    Directory of Open Access Journals (Sweden)

    VEDHACHALAM RATHINAKUMAR

    2017-03-01

    Full Text Available Stepped cascade aeration system is commonly used to aerate the water and wastewater to increase the dissolved oxygen during pre and post treatment process. In the present research, experiments were conducted to evaluate the performance of a rectangular Cascade Aeration System with varying flow rates, risers and tread by maintaining constant width of the channel using water collected from reverse osmosis plant. The experiments were carried out with four different risers such as 0.15 m, 0.18 m, 0.225 m and 0.30 m. Each rise was investigated with five different tread of 0.60 m, 0.55 m, 0.50 m, 0.45 m and 0.40 m. Comprehensive experimental investigations were carried out for different hydraulic loading rates of 0.005 to 0.035 m3/s/m2. Results obtained from the experiments reveals that increasing dimensionless discharges promotes more aeration, attains a maximum up to dimensionless discharge= 2.22 and beyond this there was a significant decrease in aeration. In addition, the increased in number of steps significantly enhances air entertainment and surface fall rate in the Stepped Cascade Aeration System. A regression equation was derived by keeping aeration efficiency as response with dimensionless discharge and oxygen saturation concentration as influencing parameters. The dimension less discharge is a function of critical depth of the rectangular channel and step height, whereas oxygen saturation concentration represents the ratio of oxygen deficit and oxygen saturation concentration. Based on the experimental results, the optimum design and/or results such as number of steps (12 numbers and hydraulic loading rate (0.025 m3/s/m2 with fixed tread width of 0.6 m were identified to achieve maximum aeration rate (0.5-0.60 in Aeration system.

  3. The Onset of Chaos via Asymptotically Period-Doubling Cascade in Fractional Order Lorenz System

    Science.gov (United States)

    Lin, Xiaofang; Liao, Binghui; Zeng, Caibin

    2017-12-01

    Little seems to be known about the chaotification problem in the framework of fractional order nonlinear systems. Based on the negative damping instability mechanism and fractional calculus technique, this paper reports the onset of chaos in fractional order Lorenz system with periodic system parameters via asymptotically period-doubling cascade. To further understand the complex dynamics of the system, some basic properties such as the largest Lyapunov exponents, bifurcation diagram, routes to chaos, asymptotically periodic windows, possible chaotic and asymptotically periodic window parameter regions, and the compound structure of the system are analyzed and demonstrated with careful numerical simulations. Of particular interest is a striking finding that fractional derivative can chaotify the globally stable periodic system without feedback control.

  4. Interrelation of structure and operational states in cascading failure of overloading lines in power grids

    Science.gov (United States)

    Xue, Fei; Bompard, Ettore; Huang, Tao; Jiang, Lin; Lu, Shaofeng; Zhu, Huaiying

    2017-09-01

    As the modern power system is expected to develop to a more intelligent and efficient version, i.e. the smart grid, or to be the central backbone of energy internet for free energy interactions, security concerns related to cascading failures have been raised with consideration of catastrophic results. The researches of topological analysis based on complex networks have made great contributions in revealing structural vulnerabilities of power grids including cascading failure analysis. However, existing literature with inappropriate assumptions in modeling still cannot distinguish the effects between the structure and operational state to give meaningful guidance for system operation. This paper is to reveal the interrelation between network structure and operational states in cascading failure and give quantitative evaluation by integrating both perspectives. For structure analysis, cascading paths will be identified by extended betweenness and quantitatively described by cascading drop and cascading gradient. Furthermore, the operational state for cascading paths will be described by loading level. Then, the risk of cascading failure along a specific cascading path can be quantitatively evaluated considering these two factors. The maximum cascading gradient of all possible cascading paths can be used as an overall metric to evaluate the entire power grid for its features related to cascading failure. The proposed method is tested and verified on IEEE30-bus system and IEEE118-bus system, simulation evidences presented in this paper suggests that the proposed model can identify the structural causes for cascading failure and is promising to give meaningful guidance for the protection of system operation in the future.

  5. Information Theory Analysis of Cascading Process in a Synthetic Model of Fluid Turbulence

    Directory of Open Access Journals (Sweden)

    Massimo Materassi

    2014-02-01

    Full Text Available The use of transfer entropy has proven to be helpful in detecting which is the verse of dynamical driving in the interaction of two processes, X and Y . In this paper, we present a different normalization for the transfer entropy, which is capable of better detecting the information transfer direction. This new normalized transfer entropy is applied to the detection of the verse of energy flux transfer in a synthetic model of fluid turbulence, namely the Gledzer–Ohkitana–Yamada shell model. Indeed, this is a fully well-known model able to model the fully developed turbulence in the Fourier space, which is characterized by an energy cascade towards the small scales (large wavenumbers k, so that the application of the information-theory analysis to its outcome tests the reliability of the analysis tool rather than exploring the model physics. As a result, the presence of a direct cascade along the scales in the shell model and the locality of the interactions in the space of wavenumbers come out as expected, indicating the validity of this data analysis tool. In this context, the use of a normalized version of transfer entropy, able to account for the difference of the intrinsic randomness of the interacting processes, appears to perform better, being able to discriminate the wrong conclusions to which the “traditional” transfer entropy would drive.

  6. Tank Cascade Systems as a Sustainable Measure of Watershed Management in South Asia

    Directory of Open Access Journals (Sweden)

    Wiebke Bebermeier

    2017-03-01

    Full Text Available In the dry zone of Sri Lanka, human-made reservoirs have served for the collection, storage and distribution of rainfall and runoff and provide irrigation water for the cultivation of paddy for 2000 years. This paper introduces the layout and function of four traditional village tank cascade systems in the hinterland of Anuradhapura, located in the North Central Province in Sri Lanka. In contrast to large-scale tanks, these systems are managed and maintained by local villagers. Sedimentological data from two tanks provide information about processes leading to the formation of these deposits and their post-sedimentary, partly human-induced alterations. The presented data support the hypothesis, that the decentral managed tanks were not affected by severe erosion after the abandonment of the ancient capital Anuradhapura in the 11th century CE, a period that was characterized by socio-economic instability and increased climatic fluctuations. Presented results underline the significance of small-scale tank cascades systems to buffer the effects of climatic fluctuations and point to their potential as a cornerstone in coping with future climate change in the dry zone of Sri Lanka.

  7. Energy Analysis of Cascade Heating with High Back-Pressure Large-Scale Steam Turbine

    Directory of Open Access Journals (Sweden)

    Zhihua Ge

    2018-01-01

    Full Text Available To reduce the exergy loss that is caused by the high-grade extraction steam of traditional heating mode of combined heat and power (CHP generating unit, a high back-pressure cascade heating technology for two jointly constructed large-scale steam turbine power generating units is proposed. The Unit 1 makes full use of the exhaust steam heat from high back-pressure turbine, and the Unit 2 uses the original heating mode of extracting steam condensation, which significantly reduces the flow rate of high-grade extraction steam. The typical 2 × 350 MW supercritical CHP units in northern China were selected as object. The boundary conditions for heating were determined based on the actual climatic conditions and heating demands. A model to analyze the performance of the high back-pressure cascade heating supply units for off-design operating conditions was developed. The load distributions between high back-pressure exhaust steam direct supply and extraction steam heating supply were described under various conditions, based on which, the heating efficiency of the CHP units with the high back-pressure cascade heating system was analyzed. The design heating load and maximum heating supply load were determined as well. The results indicate that the average coal consumption rate during the heating season is 205.46 g/kWh for the design heating load after the retrofit, which is about 51.99 g/kWh lower than that of the traditional heating mode. The coal consumption rate of 199.07 g/kWh can be achieved for the maximum heating load. Significant energy saving and CO2 emission reduction are obtained.

  8. Network analysis of oyster transcriptome revealed a cascade of cellular responses during recovery after heat shock.

    Directory of Open Access Journals (Sweden)

    Lingling Zhang

    Full Text Available Oysters, as a major group of marine bivalves, can tolerate a wide range of natural and anthropogenic stressors including heat stress. Recent studies have shown that oysters pretreated with heat shock can result in induced heat tolerance. A systematic study of cellular recovery from heat shock may provide insights into the mechanism of acquired thermal tolerance. In this study, we performed the first network analysis of oyster transcriptome by reanalyzing microarray data from a previous study. Network analysis revealed a cascade of cellular responses during oyster recovery after heat shock and identified responsive gene modules and key genes. Our study demonstrates the power of network analysis in a non-model organism with poor gene annotations, which can lead to new discoveries that go beyond the focus on individual genes.

  9. Characterisation of the Rota Wewa tank cascade system in the vicinity of Anuradhapura, Sri Lanka

    Directory of Open Access Journals (Sweden)

    Schütt, Brigitta

    2013-09-01

    Full Text Available A complex and sustainable watershed management strategy was implemented in Sri Lanka during the ancient Anuradhapura period, from the 5th century BC to the 11th century AD. Like modern watershed management strategies, it focused on flood prevention, soil erosion control, water quality control and water storage for irrigation. Tank cascade systems were the key element of these ancient watershed management installations. The wewas investigated were constructed in valleys characterised by fluvial accumulation. Sedimentological analyses of these tank cascade systems show that a precise age determination and the reconstruction of sediment and water f luxes as triggered by human-environment interactions are difficult. This is caused by the shallow character of the wewas leading to the steady redeposition of the tank sediments by wave motions during the wet season and agricultural use of the desiccated wewas during the dry season. Beyond, the sediments analysed allow to distinguish between the weathered parent bedrock and the overlying sediments. A differentiation between wewa deposits and the underlying fluvial deposits remains challenging.

  10. Prediction of Cascading Collapse Occurrence due to the Effect of Hidden Failure of a Protection System using Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Nor Hazwani Idris

    2017-06-01

    Full Text Available Transmission line act as a medium of transportation for electrical energy from a power station to the consumer. There are many factors that could cause the cascading collapse such as instability of voltage and frequency, the change of environment and weather, the software and operator error and also the failure in protection system. Protection system plays an important function in maintaining the stability and reliability of the power grid. Hidden failures in relay protection systems are the primary factors for triggering the cascading collapse. This paper presents an Artificial Neural Network (ANN model for prediction of cascading collapse occurrence due to the effect of hidden failure of protection system. The ANN model has been developed through the normalized training and testing data process with optimum number of hidden layer, the momentum rate and the learning rate. The ANN model employs probability of hidden failure, random number of line limit power flow and exposed line as its input while trip index of cascading collapse occurrence as its output. IEEE 14 bus system is used in this study to illustrate the proposed approach. The performance of the results is analysed in terms of its Mean Square Error (MSE and Correlation Coefficient (R. The results show the ANN model produce reliable prediction of cascading collapse occurrence.

  11. The Potential of a Cascaded TEG System for Waste Heat Usage in Railway Vehicles

    Science.gov (United States)

    Wilbrecht, Sebastian; Beitelschmidt, Michael

    2018-02-01

    This work focuses on the conceptual design and optimization of a near series prototype of a high-power thermoelectric generator system (TEG system) for diesel-electric locomotives. The replacement of the silencer in the exhaust line enables integration with already existing vehicles. However, compliance with the technical and legal frameworks and the assembly space requirements is just as important as the limited exhaust back pressure, the high power density and the low life cycle costs. A special emphasis is given to the comparison of cascaded two-stage Bi2Te3 and Mg2Si0.4Sn0.6/MnSi1.81 modules with single-stage Bi2Te3 modules, both manufactured in lead-frame technology. In addition to the numerous, partly competing boundary conditions for the use in rail vehicles, the additional degree of freedom from the cascaded thermoelectric modules (TEM) is considered. The problem is investigated by coupling one-dimensional multi-domain simulations with an optimization framework using a genetic algorithm. The achievable electrical power of the single-stage system is significantly higher, at 3.2 kW, than the performance of the two-stage system (2.5 kW). Although the efficiency of the two-stage system is 44.2% higher than the single-stage system, the overall power output is 22.8% lower. This is because the lower power density and the lower number of TEM more than compensates the better efficiency. Hence, the available installation space, and thus the power density, is a critical constraint for the design of TEG systems. Furthermore, for applications recovering exhaust gas enthalpy, the large temperature drop across the heat exchanger is characteristic and must be considered carefully within the design process.

  12. Ecosystem services classification: A systems ecology perspective of the cascade framework.

    Science.gov (United States)

    La Notte, Alessandra; D'Amato, Dalia; Mäkinen, Hanna; Paracchini, Maria Luisa; Liquete, Camino; Egoh, Benis; Geneletti, Davide; Crossman, Neville D

    2017-03-01

    Ecosystem services research faces several challenges stemming from the plurality of interpretations of classifications and terminologies. In this paper we identify two main challenges with current ecosystem services classification systems: i) the inconsistency across concepts, terminology and definitions, and; ii) the mix up of processes and end-state benefits, or flows and assets. Although different ecosystem service definitions and interpretations can be valuable for enriching the research landscape, it is necessary to address the existing ambiguity to improve comparability among ecosystem-service-based approaches. Using the cascade framework as a reference, and Systems Ecology as a theoretical underpinning, we aim to address the ambiguity across typologies. The cascade framework links ecological processes with elements of human well-being following a pattern similar to a production chain. Systems Ecology is a long-established discipline which provides insight into complex relationships between people and the environment. We present a refreshed conceptualization of ecosystem services which can support ecosystem service assessment techniques and measurement. We combine the notions of biomass, information and interaction from system ecology, with the ecosystem services conceptualization to improve definitions and clarify terminology. We argue that ecosystem services should be defined as the interactions (i.e. processes) of the ecosystem that produce a change in human well-being, while ecosystem components or goods, i.e. countable as biomass units, are only proxies in the assessment of such changes. Furthermore, Systems Ecology can support a re-interpretation of the ecosystem services conceptualization and related applied research, where more emphasis is needed on the underpinning complexity of the ecological system.

  13. Study of a Back-To-Back (BTB) System Using Modular Multilevel Cascade Converters for Power Distribution Systems

    OpenAIRE

    KHAMPHAKDI, PRACHA; KHAMPHAKDI, PRACHA

    2015-01-01

    This dissertation describes a modular multilevel cascade converter based on double-star chopper-cells (MMCC-DSCC). It is used to form a BTB (Back-To-Back) system installed between two 6.6-kV power distribution feeders with many distributed power generators. It is also referred to as the so-called “loop power flow controller.” A conventional BTB system employs bulky line-frequency transformers and dc-link capacitors, whereas this DSCC-based BTB system does not require either of them, thereby r...

  14. Cascading biomethane energy systems for sustainable green gas production in a circular economy.

    Science.gov (United States)

    Wall, David M; McDonagh, Shane; Murphy, Jerry D

    2017-11-01

    Biomethane is a flexible energy vector that can be used as a renewable fuel for both the heat and transport sectors. Recent EU legislation encourages the production and use of advanced, third generation biofuels with improved sustainability for future energy systems. The integration of technologies such as anaerobic digestion, gasification, and power to gas, along with advanced feedstocks such as algae will be at the forefront in meeting future sustainability criteria and achieving a green gas supply for the gas grid. This paper explores the relevant pathways in which an integrated biomethane industry could potentially materialise and identifies and discusses the latest biotechnological advances in the production of renewable gas. Three scenarios of cascading biomethane systems are developed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Three-dimensional atom localization via probe absorption in a cascade four-level atomic system

    Science.gov (United States)

    Zeng, Wei; Deng, Li; Chen, Aixi

    2018-03-01

    For an atomic system with cascade four-level type, a useful scheme about three-dimensional (3D) atom localization is proposed. In our scheme the atomic system is coherently controlled by using a radio-frequency field to couple with two-folded levels under the condition of the existence of probe absorption. Our results show that detecting precision of 3D atom localization may be obviously improved by properly adjusting the frequency detuning and strength of the radio-frequency driving field. So our scheme could be helpful to realize 3D atom localization with high-efficiency and high-precision . In the field of laser cooling or the atom nano-lithography, our studies provide potential applications.

  16. Three-dimensional atom localization via probe absorption in a cascade four-level atomic system

    Directory of Open Access Journals (Sweden)

    Zeng Wei

    2018-03-01

    Full Text Available For an atomic system with cascade four-level type, a useful scheme about three-dimensional (3D atom localization is proposed. In our scheme the atomic system is coherently controlled by using a radio-frequency field to couple with two-folded levels under the condition of the existence of probe absorption. Our results show that detecting precision of 3D atom localization may be obviously improved by properly adjusting the frequency detuning and strength of the radio-frequency driving field. So our scheme could be helpful to realize 3D atom localization with high-efficiency and high-precision . In the field of laser cooling or the atom nano-lithography, our studies provide potential applications.

  17. Comparative study of two weir type cascade solar stills with and without PCM storage using energy and exergy analysis

    International Nuclear Information System (INIS)

    Sarhaddi, Faramarz; Farshchi Tabrizi, Farshad; Aghaei Zoori, Halimeh; Mousavi, Seyed Amir Hossein Seyed

    2017-01-01

    Highlights: • Performance evaluation of cascade solar stills with PCM storage is carried out. • Model of cascade solar still is weir type. • Present study is based on numerical simulation. • Effect of operating parameters is studies on yield, energy and exergy efficiencies. - Abstract: In this paper, the comparative study of energy and exergy performance of two weir type cascade solar stills with and without PCM storage in sunny and semi-cloudy days is carried out. The governing equations of energy analysis include a set of nonlinear equations which is obtained by writing energy balance for the various components of a solar still (i.e. glass cover, brackish water, absorber plate, phase change materials). A detailed exergy analysis is carried out and various irreversibility rates in the solar still system and its exergy efficiency are introduced. In order to solve the governing equations a computer simulation program is developed. The results of a numerical simulation of the present study are in good agreement with the experimental data of previous literatures. The numerical results of the present study show that the energy and exergy performance of solar still without PCM storage is better than the solar still with PCM storage in sunny days. On the other hand, the solar still with PCM storage is preferred for semi-cloudy days due to its better energy and exergy performance. The maximum value of the energy and exergy efficiencies of the solar still without PCM for a typical sunny day are 76.69% and 6.53%, respectively. While, the maximum energy and exergy efficiencies of the solar still with PCM for a sample semi-cloudy day are 74.35% and 8.59%, respectively. Furthermore, it is observed that the highest irreversibility rate belongs to the absorber plate and its value for the solar still without PCM on typical sunny day and the solar still with PCM on semi-cloudy days is 83.1% and 78.8% of the whole of system irreversibility rates, respectively. Whereas, the

  18. Nitrogen and phosphorus in cascade multi-system tropical reservoirs: water and sediment

    Directory of Open Access Journals (Sweden)

    Pompêo Marcelo

    2017-09-01

    Full Text Available The aim of this research was to analyze the horizontal spatial heterogeneity of both water and superficial sediment quality among and within the reservoirs of the Cantareira System (CS, focusing on concentrations of N and P, attributed to the dumping of raw domestic sewage into water bodies, which is the main cause of water pollution in São Paulo State (Brazil. The CS is a multi-system complex composed of five interconnected reservoirs, with water transported by gravity through 48 km of tunnels and channels. From the last reservoir of the CS, with an output of 33 m3 s−1, the water is conducted to a water treatment plant, producing half of the water consumed by 19 million people inhabiting São Paulo city. The upstream reservoirs are more eutrophic than the downstream ones. Data also suggest that the low phytoplankton biomass (ranging from 0.9 to 14.4 μg dm−3 is regulated by the low nutrient availability, mainly of phosphorus (TP ranging from below the detection limit, <9.0 μg dm−3, to 47.3 μg dm−3. For water, the DIN/TP ratios values range from 19 to 380. The upstream reservoirs function as nutrient accumulators and the sediment is the main compartment in which P and N are stored. Although the reservoirs are located in different river basins and are not in sequence along the same river, the results suggest a marked gradient between the reservoirs, with features similar to those of cascade reservoirs. The large volumes flowing through the canals and tunnels could explain the observed pattern. The CS reservoirs can therefore be considered multi-system reservoirs in cascade, constituting a particular case of multi-system reservoirs.

  19. Functional aspects of the EGF-induced MAP kinase cascade: a complex self-organizing system approach.

    Directory of Open Access Journals (Sweden)

    Efstratios K Kosmidis

    Full Text Available The EGF-induced MAP kinase cascade is one of the most important and best characterized networks in intracellular signalling. It has a vital role in the development and maturation of living organisms. However, when deregulated, it is involved in the onset of a number of diseases. Based on a computational model describing a "surface" and an "internalized" parallel route, we use systems biology techniques to characterize aspects of the network's functional organization. We examine the re-organization of protein groups from low to high external stimulation, define functional groups of proteins within the network, determine the parameter best encoding for input intensity and predict the effect of protein removal to the system's output response. Extensive functional re-organization of proteins is observed in the lower end of stimulus concentrations. As we move to higher concentrations the variability is less pronounced. 6 functional groups have emerged from a consensus clustering approach, reflecting different dynamical aspects of the network. Mutual information investigation revealed that the maximum activation rate of the two output proteins best encodes for stimulus intensity. Removal of each protein of the network resulted in a range of graded effects, from complete silencing to intense activation. Our results provide a new "vista" of the EGF-induced MAP kinase cascade, from the perspective of complex self-organizing systems. Functional grouping of the proteins reveals an organizational scheme contrasting the current understanding of modular topology. The six identified groups may provide the means to experimentally follow the dynamics of this complex network. Also, the vulnerability analysis approach may be used for the development of novel therapeutic targets in the context of personalized medicine.

  20. Development of an Exploration-Class Cascade Distillation System: Flight Like Prototype Design Status

    Science.gov (United States)

    Sargusingh, Miriam C.; Callahan, Michael R.

    2016-01-01

    The ability to recover and purify water through physiochemical processes is crucial for realizing long-term human space missions, including both planetary habitation and space travel. Because of their robust nature, distillation systems have been actively pursued as one of the technologies for water recovery. One such technology is the Cascade Distillation System (CDS) a multi-stage vacuum rotary distiller system designed to recover water in a microgravity environment. The CDS provides a similar function to the state of the art (SOA) vapor compressor distiller (VCD) currently employed on the International Space Station, but its control scheme and ancillary components are judged to be more straightforward and simpler to implement into a more reliable and efficient system. Through the Advanced Exploration Systems (AES) Life Support Systems (LSS) Project, the NASA Johnson Space Center (JSC) in collaboration with Honeywell International is developing a second generation flight forward prototype (CDS 2.0). A preliminary design fo the CDS 2.0 was presented to the project in September 2014. Following this review, detailed design of the system continued. The existing ground test prototype was used as a platform to demonstrate key 2.0 design and operational concepts to support this effort and mitigate design risk. A volumetric prototype was also developed to evaluate the packaging design for operability and maintainability. The updated system design was reviewed by the AES LSS Project and other key stakeholders in September 2015. This paper details the status of the CDS 2.0 design.

  1. Assessment on tracking error performance of Cascade P/PI, NPID and N-Cascade controller for precise positioning of xy table ballscrew drive system

    International Nuclear Information System (INIS)

    Abdullah, L; Jamaludin, Z; Rafan, N A; Jamaludin, J; Chiew, T H

    2013-01-01

    At present, positioning plants in machine tools are looking for high degree of accuracy and robustness attributes for the purpose of compensating various disturbance forces. The objective of this paper is to assess the tracking performance of Cascade P/PI, Nonlinear PID (NPID) and Nonlinear cascade (N-Cascade) controller with the existence of disturbance forces in the form of cutting forces. Cutting force characteristics at different cutting parameters; such as spindle speed rotations is analysed using Fast Fourier Transform. The tracking performance of a Nonlinear cascade controller in presence of these cutting forces is compared with NPID controller and Cascade P/PI controller. Robustness of these controllers in compensating different cutting characteristics is compared based on reduction in the amplitudes of cutting force harmonics using Fast Fourier Transform. It is found that the N-cascade controller performs better than both NPID controller and Cascade P/PI controller. The average percentage error reduction between N-cascade controller and Cascade P/PI controller is about 65% whereas the average percentage error reduction between cascade controller and NPID controller is about 82% at spindle speed of 3000 rpm spindle speed rotation. The finalized design of N-cascade controller could be utilized further for machining application such as milling process. The implementation of N-cascade in machine tools applications will increase the quality of the end product and the productivity in industry by saving the machining time. It is suggested that the range of the spindle speed could be made wider to accommodate the needs for high speed machining

  2. Review and prospects of the CASCADE data acquisition system at CERN

    CERN Document Server

    Burckhart, Doris; Bozzoli, W; Divià, R; Lamouche, F; Gavino, J L; Matheys, J P; Perrin, Yves; Petersen, J; Saravia, A; Tremblet, L J; Van de Vyvre, P; Vascotto, Alessandro; Werner, P

    1995-01-01

    CASCADE, a multi-processor real-time data-acquisition system for HEP experiments developed at CERN by the ECP-DS group, has now been in operation for one year. The current implementation supports configurations based on VMEbus processors running OS-9 and on UNIX workstations interconnected via VICbus or Ethernet. The project is reviewed by describing the main characteristics of the package, the applications in which it has been used, and the results of this experience. The main improvements of 1994, which include a parameterized multi-level event builder, a remote monitoring option and a powerful run control facility, as well as ongoing developments and prospects for 1995, are presented.

  3. The cyclic AMP cascade is altered in the fragile X nervous system.

    Directory of Open Access Journals (Sweden)

    Daniel J Kelley

    2007-09-01

    Full Text Available Fragile X syndrome (FX, the most common heritable cause of mental retardation and autism, is a developmental disorder characterized by physical, cognitive, and behavioral deficits. FX results from a trinucleotide expansion mutation in the fmr1 gene that reduces levels of fragile X mental retardation protein (FMRP. Although research efforts have focused on FMRP's impact on mGluR signaling, how the loss of FMRP leads to the individual symptoms of FX is not known. Previous studies on human FX blood cells revealed alterations in the cyclic adenosine 3', 5'-monophosphate (cAMP cascade. We tested the hypothesis that cAMP signaling is altered in the FX nervous system using three different model systems. Induced levels of cAMP in platelets and in brains of fmr1 knockout mice are substantially reduced. Cyclic AMP induction is also significantly reduced in human FX neural cells. Furthermore, cAMP production is decreased in the heads of FX Drosophila and this defect can be rescued by reintroduction of the dfmr gene. Our results indicate that a robust defect in cAMP production in FX is conserved across species and suggest that cAMP metabolism may serve as a useful biomarker in the human disease population. Reduced cAMP induction has implications for the underlying causes of FX and autism spectrum disorders. Pharmacological agents known to modulate the cAMP cascade may be therapeutic in FX patients and can be tested in these models, thus supplementing current efforts centered on mGluR signaling.

  4. Optimization of cascade hydropower system operation by genetic algorithm to maximize clean energy output

    Directory of Open Access Journals (Sweden)

    Aida Tayebiyan

    2016-06-01

    Full Text Available Background: Several reservoir systems have been constructed for hydropower generation around the world. Hydropower offers an economical source of electricity with reduce carbon emissions. Therefore, it is such a clean and renewable source of energy. Reservoirs that generate hydropower are typically operated with the goal of maximizing energy revenue. Yet, reservoir systems are inefficiently operated and manage according to policies determined at the construction time. It is worth noting that with little enhancement in operation of reservoir system, there could be an increase in efficiency of the scheme for many consumers. Methods: This research develops simulation-optimization models that reflect discrete hedging policy (DHP to manage and operate hydropower reservoir system and analyse it in both single and multireservoir system. Accordingly, three operational models (2 single reservoir systems and 1 multi-reservoir system were constructed and optimized by genetic algorithm (GA. Maximizing the total power generation in horizontal time is chosen as an objective function in order to improve the functional efficiency in hydropower production with consideration to operational and physical limitations. The constructed models, which is a cascade hydropower reservoirs system have been tested and evaluated in the Cameron Highland and Batang Padang in Malaysia. Results: According to the given results, usage of DHP for hydropower reservoir system operation could increase the power generation output to nearly 13% in the studied reservoir system compared to present operating policy (TNB operation. This substantial increase in power production will enhance economic development. Moreover, the given results of single and multi-reservoir systems affirmed that hedging policy could manage the single system much better than operation of the multi-reservoir system. Conclusion: It can be summarized that DHP is an efficient and feasible policy, which could be used

  5. Cascading Corruption News

    DEFF Research Database (Denmark)

    Damgaard, Mads

    2018-01-01

    Through a content analysis of 8,800 news items and six months of front pages in three Brazilian newspapers, all dealing with corruption and political transgression, this article documents the remarkable skew of media attention to corruption scandals. The bias is examined as an information...... phenomenon, arising from systemic and commercial factors of Brazil’s news media: An information cascade of news on corruption formed, destabilizing the governing coalition and legitimizing the impeachment process of Dilma Rousseff. As this process gained momentum, questions of accountability were disregarded...... by the media, with harmful effects on democracy....

  6. Cascading Corruption News

    DEFF Research Database (Denmark)

    Damgaard, Mads

    2018-01-01

    Through a content analysis of 8,800 news items and six months of front pages in three Brazilian newspapers, all dealing with corruption and political transgression, this article documents the remarkable skew of media attention to corruption scandals. The bias is examined as an information...... phenomenon, arising from systemic and commercial factors of Brazil’s news media: An information cascade of news on corruption formed, destabilizing the governing coalition and legitimizing the impeachment process of Dilma Rousseff. As this process gained momentum, questions of accountability were disregarded...

  7. Molecular-dynamics simulation of displacement cascades in Cu: analysis of replacement sequences

    International Nuclear Information System (INIS)

    King, W.E.; Benedek, R.

    1981-01-01

    Molecular-dynamics computer simulations of displacement cascades in copper have been performed for recoil energies up to 450 eV. Statistical analyses of the atomic replacements are presented. Linear replacement sequence lengths are extremely short on the average. The effect of the cooling phase of the cascade is discussed

  8. CFD analysis of cascade effects in marine propellers with trailing edge modification

    DEFF Research Database (Denmark)

    Shin, Keun Woo; Andersen, Poul

    2015-01-01

    Propeller blades are different from a single hydrofoilin isolation due to cascade effects that blades mutually affect hydrodynamic characteristics of each other in proximity. Propeller design programs based lifting-line theory and blade element momentum theory take into account cascade effect by ...

  9. Application of fluorescent microscopy and cascade filtration methods for analysis of soil microbial community

    Science.gov (United States)

    Ivanov, Konstantin; Pinchuk, Irina; Gorodnichev, Roman; Polyanskaya, Lubov

    2016-04-01

    Methods establishment of soil microbial cells size estimation called from the importance of current needs of research in microbial ecology. Some of the methods need to be improved for more detailed view of changes happen in microbiome of terrestrial ecosystems. The combination of traditional microscopy methods, fluorescence and filtration in addition to cutting-edge DNA analysis gives a wide range of the approaches for soil microbial ecologists in their research questions. In the most of the cases the bacterial cells size is limited of the natural conditions such as lack of nutrients or stress factors due to heterogeneity of soil system. In the samples of soils, lakes and rivers sediments, snow and rain water the bacterial cells were detected minimally of 0.2 microns. We established the combination of the cascade filtration and fluorescent microscopy for complex analysis of different terrestrial ecosystems and various soil types. Our modification based on the use of successively filtered soil suspension for collection of microbes by the membrane pores decrease. Combination with fluorescence microscopy and DNA analysis via FISH method gave the presentation of microbial interactions and review of ecological strategies of soil microorganisms. Humus horizons of primitive arctic soil were the most favorable for bacterial growth. Quantified biomass of soil bacteria depends on the dominance of cells with specific dimensions caused of stress factors. The average bacterial size of different soil varied from 0.23 to 0.38 microns, however in humus horizons of arctic soil we detected the contrast dominance of the bigger bacterial cells sized of 1.85 microns. Fungi in this case contributed to increase the availability of organic matter for bacteria because the fungal mycelium forms the appreciable part of microbial biomass of primitive arctic soil. The dominant content of bigger bacterial cells in forest and fallow soil as well as the opposite situation in arable soils caused

  10. Multi-objective Operation Chart Optimization for Aquatic Species Habitat Conservation of Cascaded Hydropower System on Yuan River, Southwestern China

    Science.gov (United States)

    Wen, X.; Lei, X.; Fang, G.; Huang, X.

    2017-12-01

    Extensive cascading hydropower exploitation in southwestern China has been the subject of debate and conflict in recent years. Introducing limited ecological curves, a novel approach for derivation of hydropower-ecological joint operation chart of cascaded hydropower system was proposed, aiming to optimize the general hydropower and ecological benefits, and to alleviate the ecological deterioration in specific flood/dry conditions. The physical habitat simulation model is proposed initially to simulate the relationship between streamflow and physical habitat of target fish species and to determine the optimal ecological flow range of representative reach. The ecological—hydropower joint optimization model is established to produce the multi-objective operation chart of cascaded hydropower system. Finally, the limited ecological guiding curves were generated and added into the operation chart. The JS-MDS cascaded hydropower system on the Yuan River in southwestern China is employed as the research area. As the result, the proposed guiding curves could increase the hydropower production amount by 1.72% and 5.99% and optimize ecological conservation degree by 0.27% and 1.13% for JS and MDS Reservoir, respectively. Meanwhile, the ecological deterioration rate also sees a decrease from 6.11% to 1.11% for JS Reservoir and 26.67% to 3.89% for MDS Reservoir.

  11. The plasma contact system, a protease cascade at the nexus of inflammation, coagulation and immunity.

    Science.gov (United States)

    Weidmann, Henri; Heikaus, Laura; Long, Andy T; Naudin, Clément; Schlüter, Hartmut; Renné, Thomas

    2017-11-01

    The contact system is a potent procoagulant and proinflammatory plasma protease cascade that is initiated by binding ("contact")-induced, auto-activation of factor XII zymogen. Formed active serine protease FXIIa then cleaves plasma prekallikrein to kallikrein that in turn liberates the mediator bradykinin from its precursor high molecular weight kininogen. Bradykinin induces inflammation with implications for host defense and innate immunity. FXIIa also triggers the intrinsic pathway of coagulation that has been shown to critically contribute to thrombosis. Vice versa, FXII deficiency impairs thrombosis in animal models without inducing abnormal excessive bleeding. Recent work has established the FXIIa-driven contact system as promising target for anticoagulant and anti-inflammatory drugs. This review focuses on the biochemistry of the contact system, its regulation by endogenous and exogenous inhibitors, and roles in disease states. This article is part of a Special Issue entitled: Proteolysis as a Regulatory Event in Pathophysiology edited by Stefan Rose-John. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Generalized weighted crosstalk for DWDM systems with cascaded wavelength-selective switches.

    Science.gov (United States)

    Filer, Mark; Tibuleac, Sorin

    2012-07-30

    A generalized method for estimating transmission penalties from spectrally-shaped crosstalk in cascaded multi-port WSS networks is derived, including effects of ASE, signal filtering, and crosstalk filtering. The weighted crosstalk value is computed by multiplying the shaped interfering signal by the power spectral density of the primary signal. This value is used to predict OSNR penalties in networks with cascaded WSSs of arbitrary port count. Theoretical treatment is supported by extensive numerical simulations and experiments for a variety of network configurations. Examples are presented for 43 Gb/s DPSK and 120 Gb/s DP-QPSK in cascaded ROADM networks with three distinct WSS types.

  13. Role of the plasma cascade systems in ischemia/reperfusion injury of bone.

    Science.gov (United States)

    Zhang, Shengye; Wotzkow, Carlos; Bongoni, Anjan K; Shaw-Boden, Jane; Siegrist, Mark; Taddeo, Adriano; Blank, Fabian; Hofstetter, Willy; Rieben, Robert

    2017-04-01

    visible in osteocytes of the normal healthy control group, while TF was not present in the experimental groups. Moreover, CH50 values in serum decreased over time and HMGB1 was significantly increased in plasma of animals at the end of reperfusion. We conclude that ischemia and reperfusion of bone leads to activation of the complement and coagulation systems and a downregulation of the fibrinolytic cascade. In the acute phase, a vascular inflammation induced by activation of the plasma cascade systems also occurs in the bone. This is similar to I/R injury of other vascularized organs and tissues. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. External cavity-quantum cascade laser (EC-QCL) spectroscopy for protein analysis in bovine milk.

    Science.gov (United States)

    Kuligowski, Julia; Schwaighofer, Andreas; Alcaráz, Mirta Raquel; Quintás, Guillermo; Mayer, Helmut; Vento, Máximo; Lendl, Bernhard

    2017-04-22

    The analytical determination of bovine milk proteins is important in food and non-food industrial applications and yet, rather labour-intensive wet-chemical, low-throughput methods have been employed since decades. This work proposes the use of external cavity-quantum cascade laser (EC-QCL) spectroscopy for the simultaneous quantification of the most abundant bovine milk proteins and the total protein content based on the chemical information contained in mid-infrared (IR) spectral features of the amide I band. Mid-IR spectra of protein standard mixtures were used for building partial least squares (PLS) regression models. Protein concentrations in commercial bovine milk samples were calculated after chemometric compensation of the matrix contribution employing science-based calibration (SBC) without sample pre-processing. The use of EC-QCL spectroscopy together with advanced multivariate data analysis allowed the determination of casein, α-lactalbumin, β-lactoglobulin and total protein content within several minutes. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Adaptive Stabilization and Dynamic Performance Preservation of Cascaded DC-DC Systems by Incorporating Low Pass Filters

    Directory of Open Access Journals (Sweden)

    Ahmed Aldhaheri

    2018-02-01

    Full Text Available This paper proposes a method to stabilize and enhance the dynamic performance of a cascaded DC-DC system by adaptively reshaping the source output impedance. The method aims to reduce the ratio of the source output impedance to the load input impedance, referred to as the minor loop gain, to eliminate the interaction between the load and the source systems. This interaction can deteriorate the dynamic performance or might lead to instability. Thus, the bus current is used to improve the dynamic performance by reducing the magnitude of the source’s output impedance adaptively according to the loading condition such that the dynamic performance is consistently improved. Utilizing the bus current facilitates the compatibility between the proposed controller and most widely used DC-DC converters controlled in voltage mode, including non-minimum phase converters. In addition to the flexibility the bus current provides to embed the proposed solution with conventional control schemes. Experimental results have validated the effectiveness of the proposed controller along with time-based simulation and theoretical analysis, for minimum and non-minimum phase converters.

  16. Oxidant Stress and Signal Transduction in the Nervous System with the PI 3-K, Akt, and mTOR Cascade

    Directory of Open Access Journals (Sweden)

    Yan Chen Shang

    2012-10-01

    Full Text Available Oxidative stress impacts multiple systems of the body and can lead to some of the most devastating consequences in the nervous system especially during aging. Both acute and chronic neurodegenerative disorders such as diabetes mellitus, cerebral ischemia, trauma, Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, and tuberous sclerosis through programmed cell death pathways of apoptosis and autophagy can be the result of oxidant stress. Novel therapeutic avenues that focus upon the phosphoinositide 3-kinase (PI 3-K, Akt (protein kinase B, and the mammalian target of rapamycin (mTOR cascade and related pathways offer exciting prospects to address the onset and potential reversal of neurodegenerative disorders. Effective clinical translation of these pathways into robust therapeutic strategies requires intimate knowledge of the complexity of these pathways and the ability of this cascade to influence biological outcome that can vary among disorders of the nervous system.

  17. Direct utilization of geothermal heat in cascade application to aquaculture and greenhouse systems at Navarro College. Annual report, January 1984-September 1984

    Energy Technology Data Exchange (ETDEWEB)

    Smith, K.

    1984-09-01

    Progress is reported on a project to use the 130/sup 0/F geothermal resource in central Texas. The system for cascading geothermal energy through aquaculture and greenhouse systems was completed and the first shrimp harvest was held. (MHR)

  18. Wavelet cascades

    Science.gov (United States)

    Giesemann, Jens; Greiner, Martin; Lipa, Peter

    1997-02-01

    The generators of binary multiplicative cascade models with a non-overlapping branching structure are given by the Haar wavelets. We construct specific generalizations of these models for which any given wavelet represents the generators of the local cascade branchings. Such “wavelet cascades”, for which we calculate spatial correlation functions, have spatially overlapping branches and are therefore useful for modeling recombination effects in hierarchical branching processes.

  19. Multi-Agent System Based Special Protection and Emergency Control Scheme against Cascading Events in Power System

    DEFF Research Database (Denmark)

    Liu, Zhou

    on sensitivity analysis and the extent of specific emergency states. At the same time, load restoration dynamics is taken into account to compensate sensitivity calculation and correct the control algorithm. Such control methods provides a direct and simple way from problems to solutions, which is suitable...... in the lowest level of MAS. And the agents in higher levels will be used to build an effective cooperation environment. Therefore, those distributed agents can be systematically organized by MAS to effectively achieve the global goal on preventing the post fault emergency states and subsequent cascading events...... in real time. If there is an unexpected situation emerging, the agents in higher level will be activated to solve this problem. Such methods improve the reliability of the proposed protection strategy coping with more complex emergency situations than planned. Finally, in order to realize and testify...

  20. Short-term cascaded hydroelectric system scheduling based on chaotic particle swarm optimization using improved logistic map

    Science.gov (United States)

    He, Yaoyao; Yang, Shanlin; Xu, Qifa

    2013-07-01

    In order to solve the model of short-term cascaded hydroelectric system scheduling, a novel chaotic particle swarm optimization (CPSO) algorithm using improved logistic map is introduced, which uses the water discharge as the decision variables combined with the death penalty function. According to the principle of maximum power generation, the proposed approach makes use of the ergodicity, symmetry and stochastic property of improved logistic chaotic map for enhancing the performance of particle swarm optimization (PSO) algorithm. The new hybrid method has been examined and tested on two test functions and a practical cascaded hydroelectric system. The experimental results show that the effectiveness and robustness of the proposed CPSO algorithm in comparison with other traditional algorithms.

  1. Key technical issues relating to safety of spent fuel dry storage in vaults: CASCAD system

    International Nuclear Information System (INIS)

    Berge, F.

    1994-01-01

    The operating CASCAD Facility at the Cadarashe site (FR) was commissioned in May 1990. Fuel is received in tight canisters which are transferred to storage pits in the vault and scheduled to be stored for up to 50 years. Canistering operations are performed in a cell of the reactor building.The paper describes the main functions of the facility as: cask receipt and shipping; fuel unloading; fuel conditioning; canisters emplacements in storage location; fuel storage; fuel retrieving and shipping at the end of the storage period; operation system and operation organization. Safety characteristics of the facility discussed are: fuel decay heat removal; subcriticality control and radiological protection. The fuel decay heat removal has two main purposes: 1) maintaining rod cladding temperature below a set limit in order to keep the fuel in its as received condition; 2) maintaining structures and equipment performing a safety function below the design temperature. The features of the sub-criticality control in the storage vault are such that sub-criticality in normal and accidental conditions is provided by the arrangement of pits in the vault. Radiological protection is based on limiting collective and individual annual dose equivalent to ALARA levels ensuring that they remain in any case below the set limits. Radiological protection system described consists in: confinement of radioactive materials for protection against its dissemination; radiation shielding for protection against irradiation. It is pointed out that all technical solutions presented are based on or adapted from proven technologies used in operating facilities in France or in other countries. The solution not only benefits from the experience of SGN in the design, construction and start-up of facilities for fuel or high level waste handling and storage, but also from the experience of the CEA and COGEMA groups in operating such facilities. 2 figs., 1 ref

  2. Microbial network for waste activated sludge cascade utilization in an integrated system of microbial electrolysis and anaerobic fermentation

    DEFF Research Database (Denmark)

    Liu, Wenzong; He, Zhangwei; Yang, Chunxue

    2016-01-01

    and Parabacteroides, which showed a delayed contribution to the extracellular electron transport leading to a slow cascade utilization of WAS. Conclusions: Efficient pretreatment could supply more short-chain fatty acids and higher conductivities in the fermentative liquid, which facilitated mass transfer in anodic...... of interaction, which have not been sufficiently studied so far. It is therefore important to understand how choosing operational parameters can influence reactor performances. The current study highlights the interaction offermentative bacteria and exoelectrogens in the integrated system....

  3. Postsynaptic dorsal column and cuneate correlations in the raccoon: a re-evaluation by parallel-cascade analysis.

    Science.gov (United States)

    French, Andrew S; Dick, Susan H; Rasmusson, Douglas D

    2002-12-01

    In a previous study, we reported evidence for correlations between the firing of postsynaptic dorsal column (PSDC) neurons and cuneate neurons with overlapping receptive fields on the glabrous skin of the raccoon forepaw. The evidence was based on cross-correlation and frequency response analyses of spontaneously firing neurons. However, cross-correlation without white noise Gaussian analog inputs or Poisson distributed pulse train inputs is difficult to interpret because of the inherent convolution with the autocorrelation of the unknown input signals. While the data suggested positive correlations in the spinocuneate direction for most neuron pairs, we could not estimate the temporal characteristics of these putative connections. We have now re-analyzed these data using a parallel-cascade method to estimate the first- and second-order kernels of a Volterra series approximation to the spinocuneate system. This unbiased analysis suggests that a positive correlation occurs after about 5 ms, probably followed by a negative correlation at about 12 ms. Second-order kernels also had repeatable structure, indicating dual pathways with time separations of at least 10 ms.

  4. Molecular Analysis of Sensory Axon Branching Unraveled a cGMP-Dependent Signaling Cascade

    Directory of Open Access Journals (Sweden)

    Alexandre Dumoulin

    2018-04-01

    Full Text Available Axonal branching is a key process in the establishment of circuit connectivity within the nervous system. Molecular-genetic studies have shown that a specific form of axonal branching—the bifurcation of sensory neurons at the transition zone between the peripheral and the central nervous system—is regulated by a cyclic guanosine monophosphate (cGMP-dependent signaling cascade which is composed of C-type natriuretic peptide (CNP, the receptor guanylyl cyclase Npr2, and cGMP-dependent protein kinase Iα (cGKIα. In the absence of any one of these components, neurons in dorsal root ganglia (DRG and cranial sensory ganglia no longer bifurcate, and instead turn in either an ascending or a descending direction. In contrast, collateral axonal branch formation which represents a second type of axonal branch formation is not affected by inactivation of CNP, Npr2, or cGKI. Whereas axon bifurcation was lost in mouse mutants deficient for components of CNP-induced cGMP formation; the absence of the cGMP-degrading enzyme phosphodiesterase 2A had no effect on axon bifurcation. Adult mice that lack sensory axon bifurcation due to the conditional inactivation of Npr2-mediated cGMP signaling in DRG neurons demonstrated an altered shape of sensory axon terminal fields in the spinal cord, indicating that elaborate compensatory mechanisms reorganize neuronal circuits in the absence of bifurcation. On a functional level, these mice showed impaired heat sensation and nociception induced by chemical irritants, whereas responses to cold sensation, mechanical stimulation, and motor coordination are normal. These data point to a critical role of axon bifurcation for the processing of acute pain perception.

  5. Analysis of energy cascade utilization in a chemically recuperated scramjet with indirect combustion

    International Nuclear Information System (INIS)

    Qin, Jiang; Cheng, Kunlin; Zhang, Silong; Zhang, Duo; Bao, Wen; Han, Jiecai

    2016-01-01

    The working process of scramjet with regenerative cooling, which was actually the chemical recuperation process, was analyzed in view of energy cascade utilization. The indirect combustion was realized through pyrolysis reaction of fuel. The relative yields of thermal exergy obtained by indirect combustion have been predicted both assuming an ideal pyrolysis reaction and using the experimental results of thermal pyrolysis of n-decane. The results showed that the influence mechanism of regenerative cooling improved the scramjet engine performance by the energy cascade utilization, and the combustion process was supposed to be designed with the cooling process together to utilize the chemical energy of fuel in a more effective way. A maximum value of 11% of the relative yield was obtained with the ideal pyrolysis reaction while a value less than 3% existed in the thermal pyrolysis experiments because of the domination of chemical kinetics rather than chemical thermodynamics in the real experiments. In spite of the difference between the ideal and the present experimental results, the indirect combustion was prospective to achieve a better energy cascade utilization in a chemically recuperated scramjet if the pyrolysis reaction was further optimized. The results in this paper were beneficial for the performance optimization of a regenerative cooling scramjet. - Highlights: • A new method of energy cascade utilization in a chemically recuperated scramjet. • 11% exergy loss is reduced by ideal pyrolysis reaction with indirect combustion. • Regenerative cooling with chemical recuperation can improve engine performance.

  6. Microbial network for waste activated sludge cascade utilization in an integrated system of microbial electrolysis and anaerobic fermentation

    DEFF Research Database (Denmark)

    Liu, Wenzong; He, Zhangwei; Yang, Chunxue

    2016-01-01

    Background: Bioelectrochemical systems have been considered a promising novel technology that shows an enhanced energy recovery, as well as generation of value-added products. A number of recent studies suggested that an enhancement of carbon conversion and biogas production can be achieved...... and Parabacteroides, which showed a delayed contribution to the extracellular electron transport leading to a slow cascade utilization of WAS. Conclusions: Efficient pretreatment could supply more short-chain fatty acids and higher conductivities in the fermentative liquid, which facilitated mass transfer in anodic...... biofilm. The overall performance of WAS cascade utilization was substantially related to the microbial community structures, which in turn depended on the initial pretreatment to enhance WAS fermentation. It is worth noting that species in AD and MEC communities are able to build complex networks...

  7. Hybrid Systems Based on Layered Silicate and Organic Dyes for Cascade Energy Transfer

    Czech Academy of Sciences Publication Activity Database

    Belušáková, S.; Lang, Kamil; Bujdák, J.

    2015-01-01

    Roč. 119, č. 38 (2015), s. 21784-21794 ISSN 1932-7447 Institutional support: RVO:61388980 Keywords : Cascade energy transfers * Multicomponent films * Resonance energy transfer * Spectral properties * Steady state fluorescence * Time -resolved fluorescence spectroscopy Subject RIV: CA - Inorganic Chemistry Impact factor: 4.509, year: 2015

  8. Robustness analysis of complex networks with power decentralization strategy via flow-sensitive centrality against cascading failures

    Science.gov (United States)

    Guo, Wenzhang; Wang, Hao; Wu, Zhengping

    2018-03-01

    Most existing cascading failure mitigation strategy of power grids based on complex network ignores the impact of electrical characteristics on dynamic performance. In this paper, the robustness of the power grid under a power decentralization strategy is analysed through cascading failure simulation based on AC flow theory. The flow-sensitive (FS) centrality is introduced by integrating topological features and electrical properties to help determine the siting of the generation nodes. The simulation results of the IEEE-bus systems show that the flow-sensitive centrality method is a more stable and accurate approach and can enhance the robustness of the network remarkably. Through the study of the optimal flow-sensitive centrality selection for different networks, we find that the robustness of the network with obvious small-world effect depends more on contribution of the generation nodes detected by community structure, otherwise, contribution of the generation nodes with important influence on power flow is more critical. In addition, community structure plays a significant role in balancing the power flow distribution and further slowing the propagation of failures. These results are useful in power grid planning and cascading failure prevention.

  9. Analysis of a wavelength selectable cascaded DFB laser based on the transfer matrix method

    International Nuclear Information System (INIS)

    Xie Hongyun; Chen Liang; Shen Pei; Sun Botao; Wang Renqing; Xiao Ying; You Yunxia; Zhang Wanrong

    2010-01-01

    A novel cascaded DFB laser, which consists of two serial gratings to provide selectable wavelengths, is presented and analyzed by the transfer matrix method. In this method, efficient facet reflectivity is derived from the transfer matrix built for each serial section and is then used to simulate the performance of the novel cascaded DFB laser through self-consistently solving the gain equation, the coupled wave equation and the current continuity equations. The simulations prove the feasibility of this kind of wavelength selectable laser and a corresponding designed device with two selectable wavelengths of 1.51 μm and 1.53 μm is realized by experiments on InP-based multiple quantum well structure. (semiconductor devices)

  10. Energy and exergy analysis of a new ejector enhanced auto-cascade refrigeration cycle

    International Nuclear Information System (INIS)

    Yan, Gang; Chen, Jiaheng; Yu, Jianlin

    2015-01-01

    Highlights: • A new ejector enhanced auto-cascade refrigeration cycle using R134a/R23 is proposed. • The performance of new and basic cycles is compared by simulation method. • The new cycle outperforms the basic cycle in both energetic and exergy aspects. • Both cycles have optimum mixture compositions to obtain optimal performance. - Abstract: A new ejector enhanced auto-cascade refrigeration cycle using R134a/R23 refrigerant mixture is proposed in this paper. In the new cycle, an ejector is used to recover part of the work that would otherwise be lost in the throttling processes. The performance comparison between the new cycle and a basic auto-cascade refrigeration cycle is carried out based on the first and second laws of thermodynamics. The simulation results show that both the coefficient of performance and exergy efficiency of the new cycle can be improved by 8.42–18.02% compared with those of the basic cycle at the same operation conditions as the ejector has achieved pressure lift ratios of 1.12–1.23. It is found that in the new cycle, the highest exergy destruction occurs in the compressor followed by the condenser, cascade condenser, expansion valve, ejector and evaporator. The effect of some main parameters on the cycle performance is further investigated. The results show that for the new cycle, the achieved performance improvement over the basic cycle is also dependent on the mixture composition and the vapor quality at the condenser outlet. The coefficient of performance improvement of the new cycle over the basic cycle degrades with increasing vapor quality. In addition, there exists an optimum mixture composition to obtain the maximum coefficient of performance for the new cycle when other operation conditions are given. The optimum mixture composition of both cycles may be fixed at about 0.5 under the given evaporating temperature.

  11. Cascades, ``Blobby'' Turbulence, and Target Pattern Formation in Elastic Systems: A New Take on Classic Themes in Plasma Turbulence

    Science.gov (United States)

    Fan, Xiang

    2017-10-01

    Concerns central to understanding turbulence and transport include: 1) Dynamics of dual cascades in EM turbulence; 2) Understanding `negative viscosity phenomena' in drift-ZF systems; 3) The physics of blobby turbulence (re: SOL). Here, we present a study of a simple model - that of Cahn-Hilliard Navier-Stokes (CHNS) Turbulence - which sheds important new light on these issues. The CHNS equations describe the motion of binary fluid undergoing a second order phase transition and separation called spinodal decomposition. The CHNS system and 2D MHD are analogous, as they both contain a vorticity equation and a ``diffusion'' equation. The CHNS system differs from 2D MHD by the appearance of negative diffusivity, and a nonlinear dissipative flux. An analogue of the Alfven wave exists in the 2D CHNS system. DNS shows that mean square concentration spectrum Hkψ scales as k - 7 / 3 in the elastic range. This suggests an inverse cascade of Hψ . However, the kinetic energy spectrum EkK scales as k-3 , as in the direct enstrophy cascade range for a 2D fluid (not MHD!). The resolution is that the feedback of capillarity acts only at blob interfaces. Thus, as blob merger progresses, the packing fraction of interfaces decreases, thus explaining the weakened surface tension feedback and the outcome for EkK. We also examine the evolution of scalar concentration in a single eddy in the Cahn-Hilliard system. This extends the classic problem of flux expulsion in 2D MHD. The simulation results show that a target pattern is formed. Target pattern is a meta stable state, since the band merger process continues on a time scale exponentially long relative to the eddy turnover time. Band merger resembles step merger in drift-ZF staircases. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Fusion Energy Sciences, under Award Number DE-FG02-04ER54738.

  12. Cascade Optimization for Aircraft Engines With Regression and Neural Network Analysis - Approximators

    Science.gov (United States)

    Patnaik, Surya N.; Guptill, James D.; Hopkins, Dale A.; Lavelle, Thomas M.

    2000-01-01

    The NASA Engine Performance Program (NEPP) can configure and analyze almost any type of gas turbine engine that can be generated through the interconnection of a set of standard physical components. In addition, the code can optimize engine performance by changing adjustable variables under a set of constraints. However, for engine cycle problems at certain operating points, the NEPP code can encounter difficulties: nonconvergence in the currently implemented Powell's optimization algorithm and deficiencies in the Newton-Raphson solver during engine balancing. A project was undertaken to correct these deficiencies. Nonconvergence was avoided through a cascade optimization strategy, and deficiencies associated with engine balancing were eliminated through neural network and linear regression methods. An approximation-interspersed cascade strategy was used to optimize the engine's operation over its flight envelope. Replacement of Powell's algorithm by the cascade strategy improved the optimization segment of the NEPP code. The performance of the linear regression and neural network methods as alternative engine analyzers was found to be satisfactory. This report considers two examples-a supersonic mixed-flow turbofan engine and a subsonic waverotor-topped engine-to illustrate the results, and it discusses insights gained from the improved version of the NEPP code.

  13. Analysis and compensation for the cascade dead-zones in the proportional control valve.

    Science.gov (United States)

    Xu, Bing; Su, Qi; Zhang, Junhui; Lu, Zhenyu

    2017-01-01

    The four-way proportional directional control valve has been widely used as the main stage spring constant for the two-stage proportional control valve (PDV). Since a tradeoff should be made between manufacturing costs and static performance, two symmetry dead-zones are introduced in the main stage spring constant: the center dead-zone caused by the center floating position and the intermediate dead-zone caused by the intermediate position. Though the intermediate dead-zone is much smaller than the center dead-zone, it has significant effect on the dynamic position tracking performance. In this paper, the cascade dead-zones problem in a typical two-stage PDV is analyzed and a cascade dead-zones model is proposed for the main stage spring constant. Then, a cascade dead-zones inverse method is improved with gain estimation and dead-zone detection to compensate the dead-zone nonlinearity. Finally, a digital controller is designed for verification. The comparative experimental results indicate that it is effective to reduce the large position tracking error when the proposed method is applied. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  14. Cascade-pond System Health Assessment Based on Macroinvertebrate Indices and Its Relationship with Impervious Cover and Aquatic Buffer Zone in Urbanized Catchments

    Directory of Open Access Journals (Sweden)

    Zulkarnain Faris

    2017-01-01

    Full Text Available A cascade-pond system consists of six ponds located at Universitas Indonesia Campus, Depok. Its catchment area is dominated by high density urban area with moderate to high imperviousness. Some of riparian buffers surrounds six ponds are also occupied by high imperviousness that may lead some ecohydrological problems i.e. water quality degradation, declining freshwater biodiversity and food web changes. The aim of this study is assessing the current state of cascade-pond system health. The assessment of macroinvertebrate indices is based on SingScore that have been developed by Public Utilities Board of Singapore for macroinvertebrate biotic index. Impervious cover data is obtained from high-resolution imageries and processed using ArcGIS 10.5. Qualitative statistics methods, Chi-squared test describes the relationship of macroinvertebrate indices with catchment area imperviousness and aquatic buffer zone. The health assessment based on macroinvertebrates indices shows that the lower ponds are relatively healthier than the upper one. There is also any significant relationship between macroinvertebrate indices with impervious cover based on chi square test and cross tabulation analysis.

  15. Cascade Error Projection Learning Algorithm

    Science.gov (United States)

    Duong, T. A.; Stubberud, A. R.; Daud, T.

    1995-01-01

    A detailed mathematical analysis is presented for a new learning algorithm termed cascade error projection (CEP) and a general learning frame work. This frame work can be used to obtain the cascade correlation learning algorithm by choosing a particular set of parameters.

  16. Cascade degradation of organic matters in brewery wastewater using a continuous stirred microbial electrochemical reactor and analysis of microbial communities

    OpenAIRE

    Wang, Haiman; Qu, Youpeng; Li, Da; Ambuchi, John J.; He, Weihua; Zhou, Xiangtong; Liu, Jia; Feng, Yujie

    2016-01-01

    A continuous stirred microbial electrochemical reactor (CSMER), comprising of a complete mixing zone (CMZ) and microbial electrochemical zone (MEZ), was used for brewery wastewater treatment. The system realized 75.4???5.7% of TCOD and 64.9???4.9% of TSS when fed with brewery wastewater concomitantly achieving an average maximum power density of 304???31?m W m?2. Cascade utilization of organic matters made the CSMER remove a wider range of substrates compared with a continuous stirred tank re...

  17. Cascade Organic Solar Cells

    KAUST Repository

    Schlenker, Cody W.

    2011-09-27

    We demonstrate planar organic solar cells consisting of a series of complementary donor materials with cascading exciton energies, incorporated in the following structure: glass/indium-tin-oxide/donor cascade/C 60/bathocuproine/Al. Using a tetracene layer grown in a descending energy cascade on 5,6-diphenyl-tetracene and capped with 5,6,11,12-tetraphenyl- tetracene, where the accessibility of the π-system in each material is expected to influence the rate of parasitic carrier leakage and charge recombination at the donor/acceptor interface, we observe an increase in open circuit voltage (Voc) of approximately 40% (corresponding to a change of +200 mV) compared to that of a single tetracene donor. Little change is observed in other parameters such as fill factor and short circuit current density (FF = 0.50 ± 0.02 and Jsc = 2.55 ± 0.23 mA/cm2) compared to those of the control tetracene-C60 solar cells (FF = 0.54 ± 0.02 and Jsc = 2.86 ± 0.23 mA/cm2). We demonstrate that this cascade architecture is effective in reducing losses due to polaron pair recombination at donor-acceptor interfaces, while enhancing spectral coverage, resulting in a substantial increase in the power conversion efficiency for cascade organic photovoltaic cells compared to tetracene and pentacene based devices with a single donor layer. © 2011 American Chemical Society.

  18. Analysis of Cascaded Soliton Spectral Tunneling Effect in Segmented Fibers With Engineered Dispersion

    DEFF Research Database (Denmark)

    Wang, Shaofei; Guo, Hairun; Fan, Dengfeng

    2013-01-01

    The cascaded soliton spectral tunneling (SST) effect is proposed and numerically investigated in multiple optical fiber segments, which work together to transfer the soliton pulse over a wide wavelength span. A triple-cladding fiber and a solid core step-index photonic crystal fiber are carefully...... be flexible tuned by tailoring the position of ZDWs. Numerical simulations in both fiber segments are shown, and a soliton transfer over 570 nm is demonstrated with two fiber segments. Meanwhile, soliton pulse compression and supercontinuum generation are also observed to accompany each SST effect....

  19. Quantification of the glycogen cascade system: the ultrasensitive responses of liver glycogen synthase and muscle phosphorylase are due to distinctive regulatory designs

    Directory of Open Access Journals (Sweden)

    Venkatesh KV

    2005-05-01

    Full Text Available Abstract Background Signaling pathways include intricate networks of reversible covalent modification cycles. Such multicyclic enzyme cascades amplify the input stimulus, cause integration of multiple signals and exhibit sensitive output responses. Regulation of glycogen synthase and phosphorylase by reversible covalent modification cycles exemplifies signal transduction by enzyme cascades. Although this system for regulating glycogen synthesis and breakdown appears similar in all tissues, subtle differences have been identified. For example, phosphatase-1, a dephosphorylating enzyme of the system, is regulated quite differently in muscle and liver. Do these small differences in regulatory architecture affect the overall performance of the glycogen cascade in a specific tissue? We address this question by analyzing the regulatory structure of the glycogen cascade system in liver and muscle cells at steady state. Results The glycogen cascade system in liver and muscle cells was analyzed at steady state and the results were compared with literature data. We found that the cascade system exhibits highly sensitive switch-like responses to changes in cyclic AMP concentration and the outputs are surprisingly different in the two tissues. In muscle, glycogen phosphorylase is more sensitive than glycogen synthase to cyclic AMP, while the opposite is observed in liver. Furthermore, when the liver undergoes a transition from starved to fed-state, the futile cycle of simultaneous glycogen synthesis and degradation switches to reciprocal regulation. Under such a transition, different proportions of active glycogen synthase and phosphorylase can coexist due to the varying inhibition of glycogen-synthase phosphatase by active phosphorylase. Conclusion The highly sensitive responses of glycogen synthase in liver and phosphorylase in muscle to primary stimuli can be attributed to distinctive regulatory designs in the glycogen cascade system. The different

  20. Expression Analysis of the Hippo Cascade Indicates a Role in Pituitary Stem Cell Development

    Directory of Open Access Journals (Sweden)

    Emily J Lodge

    2016-03-01

    Full Text Available The pituitary gland is a primary endocrine organ that controls major physiological processes. Abnormal development or homeostatic disruptions can lead to human disorders such as hypopituitarism or tumours. Multiple signalling pathways, including WNT, BMP, FGF and SHH regulate pituitary development but the role of the Hippo-YAP1/TAZ cascade is currently unknown. In multiple tissues, the Hippo kinase cascade underlies neoplasias; it influences organ size through the regulation of proliferation and apoptosis, and has roles in determining stem cell potential. We have used a sensitive mRNA in situ hybridisation method (RNAscope to determine the expression patterns of the Hippo pathway components during mouse pituitary development. We have also carried out immunolocalisation studies to determine when YAP1 and TAZ, the transcriptional effectors of the Hippo pathway, are active. We find that YAP1/TAZ are active in the stem/progenitor cell population throughout development and at postnatal stages, consistent with their role in promoting the stem cell state. Our results demonstrate for the first time the collective expression of major components of the Hippo pathway during normal embryonic and postnatal development of the pituitary gland.

  1. Enhancing productivity for cascade biotransformation of styrene to (S)-vicinal diol with biphasic system in hollow fiber membrane bioreactor.

    Science.gov (United States)

    Gao, Pengfei; Wu, Shuke; Praveen, Prashant; Loh, Kai-Chee; Li, Zhi

    2017-03-01

    Biotransformation is a green and useful tool for sustainable and selective chemical synthesis. However, it often suffers from the toxicity and inhibition from organic substrates or products. Here, we established a hollow fiber membrane bioreactor (HFMB)-based aqueous/organic biphasic system, for the first time, to enhance the productivity of a cascade biotransformation with strong substrate toxicity and inhibition. The enantioselective trans-dihydroxylation of styrene to (S)-1-phenyl-1,2-ethanediol, catalyzed by Escherichia coli (SSP1) coexpressing styrene monooxygenase and an epoxide hydrolase, was performed in HFMB with organic solvent in the shell side and aqueous cell suspension in the lumen side. Various organic solvents were investigated, and n-hexadecane was found as the best for the HFMB-based biphasic system. Comparing to other reported biphasic systems assisted by HFMB, our system not only shield much of the substrate toxicity but also deflate the product recovery burden in downstream processing as the majority of styrene stayed in organic phase while the diol product mostly remained in the aqueous phase. The established HFMB-based biphasic system enhanced the production titer to 143 mM, being 16-fold higher than the aqueous system and 1.6-fold higher than the traditional dispersive partitioning biphase system. Furthermore, the combination of biphasic system with HFMB prevents the foaming and emulsification, thus reducing the burden in downstream purification. HFMB-based biphasic system could serve as a suitable platform for enhancing the productivity of single-step or cascade biotransformation with toxic substrates to produce useful and valuable chemicals.

  2. Three-dimensional Navier-Stokes analysis and redesign of an imbedded bellmouth nozzle in a turbine cascade inlet section

    Science.gov (United States)

    VanFossen, G. J.; Lopez, L.; Giel, P. W.; Sirbaugh, J. R.

    1996-01-01

    Experimental measurements in the inlet of a transonic turbine blade cascade showed unacceptable pitchwise flow non-uniformity. A three-dimensional, Navier-Stokes computational fluid dynamics (CFD) analysis of the imbedded bellmouth inlet in the facility was performed to identify and eliminate the source of the flow non-uniformity. The blockage and acceleration effects of the blades were accounted for by specifying a periodic static pressure exit condition interpolated from a separate three-dimensional Navier-Stokes CFD solution of flow around a single blade in an infinite cascade. Calculations of the original inlet geometry showed total pressure loss regions consistent in strength and location to experimental measurements. The results indicate that the distortions were caused by a pair of streamwise vortices that originated as a result of the interaction of the flow with the imbedded bellmouth. Computations were performed for an inlet geometry which eliminated the imbedded bellmouth by bridging the region between it and the upstream wall. This analysis indicated that eliminating the imbedded bellmouth nozzle also eliminates the pair of vortices, resulting in a flow with much greater pitchwise uniformity. Measurements taken with an installed redesigned inlet verify that the flow non-uniformity has indeed been eliminated.

  3. Trophic structure of the benthic invertebrate community in the littoral zone of a mountain cascade system

    Directory of Open Access Journals (Sweden)

    M. Prus

    2002-02-01

    Full Text Available The cascade of Solina/Myczkowce dam reservoirs situated in the West Carpathian Mts was investigated. The cascade consists of two reservoirs, the upper one built 35 yr ago on the San and Solinka Rivers of 2100 ha area separated from another one, of 190 ha area, with hypolimnion cold water supplied from the upper one.

    The offshore zone was investigated monthly (6 sites of upper, 3 sites of lower reservoir using a tube bottom sampler. Besides numbers, biomass and biodiversity indices, the proportion of predators, plant/detritus-feeders and filter-feeders was assessed.

    In upper reservoir Solina, with a lack of filter-feeders, a clear preponderance of plant-detritus feeders was observed. Predators, consisting mostly of leeches and hydranchnellids were present. In lower reservoir Myczkowce, all three trophic classes were present in the first year of study in almost equal proportions and in 1998 with slight preponderance of plant/detritus feeders was observed.

    The Oligochaeta/Chironomidae index in both reservoirs was low, indicating low degree of eutrophication. Only one site in Solina reservoir (near a fish culture and one in Myczkowce (influenced by tourist activity showed a high value of this index.

  4. Cascade Support Vector Machines with Dimensionality Reduction

    Directory of Open Access Journals (Sweden)

    Oliver Kramer

    2015-01-01

    Full Text Available Cascade support vector machines have been introduced as extension of classic support vector machines that allow a fast training on large data sets. In this work, we combine cascade support vector machines with dimensionality reduction based preprocessing. The cascade principle allows fast learning based on the division of the training set into subsets and the union of cascade learning results based on support vectors in each cascade level. The combination with dimensionality reduction as preprocessing results in a significant speedup, often without loss of classifier accuracies, while considering the high-dimensional pendants of the low-dimensional support vectors in each new cascade level. We analyze and compare various instantiations of dimensionality reduction preprocessing and cascade SVMs with principal component analysis, locally linear embedding, and isometric mapping. The experimental analysis on various artificial and real-world benchmark problems includes various cascade specific parameters like intermediate training set sizes and dimensionalities.

  5. Computer simulation of displacement cascades in copper

    International Nuclear Information System (INIS)

    Heinisch, H.L.

    1983-06-01

    More than 500 displacement cascades in copper have been generated with the computer simulation code MARLOWE over an energy range pertinent to both fission and fusion neutron spectra. Three-dimensional graphical depictions of selected cascades, as well as quantitative analysis of cascade shapes and sizes and defect densities, illustrate cascade behavior as a function of energy. With increasing energy, the transition from production of single compact damage regions to widely spaced multiple damage regions is clearly demonstrated

  6. Application of Recurrence Analysis to the period doubling cascade of a confined buoyant flow

    International Nuclear Information System (INIS)

    Angeli, D; Corticelli, M A; Fichera, A; Pagano, A

    2017-01-01

    Recurrence Analysis (RA) is a promising and flexible tool to identify the behaviour of nonlinear dynamical systems. The potentialities of such a technique are explored in the present work, for the study of transitions to chaos of buoyant flow in enclosures. The case of a hot cylindrical source centred in a square enclosure, is considered here, for which an extensive database of results has been collected in recent years. For a specific value of the system aspect ratio, a sequence of period doublings has been identified, leading to the onset of chaos. RA is applied here to analyse the different flow regimes along the route to chaos. The qualitative visual identification of patterns and the statistics given by the quantitative analysis suggest that this kind of tool is well suited to the study of transitional flows in thermo-fluid dynamics. (paper)

  7. Geant4 Hadronic Cascade Models and CMS Data Analysis : Computational Challenges in the LHC era

    CERN Document Server

    Heikkinen, Aatos

    This work belongs to the field of computational high-energy physics (HEP). The key methods used in this thesis work to meet the challenges raised by the Large Hadron Collider (LHC) era experiments are object-orientation with software engineering, Monte Carlo simulation, the computer technology of clusters, and artificial neural networks. The first aspect discussed is the development of hadronic cascade models, used for the accurate simulation of medium-energy hadron-nucleus reactions, up to 10 GeV. These models are typically needed in hadronic calorimeter studies and in the estimation of radiation backgrounds. Various applications outside HEP include the medical field (such as hadron treatment simulations), space science (satellite shielding), and nuclear physics (spallation studies). Validation results are presented for several significant improvements released in Geant4 simulation tool, and the significance of the new models for computing in the Large Hadron Collider era is estimated. In particular, we es...

  8. Parametric amplification and cascaded-nonlinearity processes in common atomic system.

    Science.gov (United States)

    Zheng, Huaibin; Zhang, Xun; Zhang, Zhaoyang; Tian, Yaling; Chen, Haixia; Li, Changbiao; Zhang, Yanpeng

    2013-01-01

    For the first time, we study the parametric amplification process of multi-wave mixing (PA-MWM) signal and cascaded-nonlinearity process (CNP) in sodium vapors both theoretically and experimentally, based on a conventional phase-conjugate MWM and a self-diffraction four-wave mixing (SD-FWM) processes, which are pumped by laser or amplified spontaneous emission (ASE), respectively. For laser pumping case, SD-FWM process serves as a quantum linear amplifier (a CNP) out (inside) of the resonant absorption region. While for ASE case, only the CNP occurs and the output linewidth is much narrower than that of the MWM signal due to the second selected effect of its electromagnetically induced transparency window. In addition, the phase-sensitive amplifying process seeded by two MWM processes is discussed for the first time. Theoretical fittings agree well with the experiment. The investigations have important potential applications in quantum communication.

  9. Structurally Controlled Geothermal Systems in the Central Cascades Arc-Backarc Regime, Oregon

    Energy Technology Data Exchange (ETDEWEB)

    Wannamaker, Philip E. [Univ. of Utah, Salt Lake City, UT (United States). Energy and Geoscience Inst. (EGI)

    2016-07-31

    The goal of this project has been to analyze available magnetotelluric (MT) geophysical surveys, structural geology based on mapping and LiDAR, and fluid geochemical data, to identify high-temperature fluid upwellings, critically stressed rock volumes, and other evidence of structurally-controlled geothermal resources. Data were to be integrated to create conceptual models of volcanic-hosted geothermal resources along the Central Cascades arc segment, especially in the vicinity of Mt. Jefferson to Three Sisters. LiDAR data sets available at Oregon State University (OSU) allowed detailed structural geology modeling through forest canopy. Copious spring and well fluid chemistries, including isotopes, were modeled using Geo-T and TOUGHREACT software.

  10. Multi-vehicle detection with identity awareness using cascade Adaboost and Adaptive Kalman filter for driver assistant system.

    Directory of Open Access Journals (Sweden)

    Baofeng Wang

    Full Text Available Vision-based vehicle detection is an important issue for advanced driver assistance systems. In this paper, we presented an improved multi-vehicle detection and tracking method using cascade Adaboost and Adaptive Kalman filter(AKF with target identity awareness. A cascade Adaboost classifier using Haar-like features was built for vehicle detection, followed by a more comprehensive verification process which could refine the vehicle hypothesis in terms of both location and dimension. In vehicle tracking, each vehicle was tracked with independent identity by an Adaptive Kalman filter in collaboration with a data association approach. The AKF adaptively adjusted the measurement and process noise covariance through on-line stochastic modelling to compensate the dynamics changes. The data association correctly assigned different detections with tracks using global nearest neighbour(GNN algorithm while considering the local validation. During tracking, a temporal context based track management was proposed to decide whether to initiate, maintain or terminate the tracks of different objects, thus suppressing the sparse false alarms and compensating the temporary detection failures. Finally, the proposed method was tested on various challenging real roads, and the experimental results showed that the vehicle detection performance was greatly improved with higher accuracy and robustness.

  11. Multi-vehicle detection with identity awareness using cascade Adaboost and Adaptive Kalman filter for driver assistant system.

    Science.gov (United States)

    Wang, Baofeng; Qi, Zhiquan; Chen, Sizhong; Liu, Zhaodu; Ma, Guocheng

    2017-01-01

    Vision-based vehicle detection is an important issue for advanced driver assistance systems. In this paper, we presented an improved multi-vehicle detection and tracking method using cascade Adaboost and Adaptive Kalman filter(AKF) with target identity awareness. A cascade Adaboost classifier using Haar-like features was built for vehicle detection, followed by a more comprehensive verification process which could refine the vehicle hypothesis in terms of both location and dimension. In vehicle tracking, each vehicle was tracked with independent identity by an Adaptive Kalman filter in collaboration with a data association approach. The AKF adaptively adjusted the measurement and process noise covariance through on-line stochastic modelling to compensate the dynamics changes. The data association correctly assigned different detections with tracks using global nearest neighbour(GNN) algorithm while considering the local validation. During tracking, a temporal context based track management was proposed to decide whether to initiate, maintain or terminate the tracks of different objects, thus suppressing the sparse false alarms and compensating the temporary detection failures. Finally, the proposed method was tested on various challenging real roads, and the experimental results showed that the vehicle detection performance was greatly improved with higher accuracy and robustness.

  12. Benthic meiofaunal community response to the cascading effects of herbivory within an algal halo system of the Great Barrier Reef.

    Science.gov (United States)

    Ollivier, Quinn R; Hammill, Edward; Booth, David J; Madin, Elizabeth M P; Hinchliffe, Charles; Harborne, Alastair R; Lovelock, Catherine E; Macreadie, Peter I; Atwood, Trisha B

    2018-01-01

    Benthic fauna play a crucial role in organic matter decomposition and nutrient cycling at the sediment-water boundary in aquatic ecosystems. In terrestrial systems, grazing herbivores have been shown to influence below-ground communities through alterations to plant distribution and composition, however whether similar cascading effects occur in aquatic systems is unknown. Here, we assess the relationship between benthic invertebrates and above-ground fish grazing across the 'grazing halos' of Heron Island lagoon, Australia. Grazing halos, which occur around patch reefs globally, are caused by removal of seagrass or benthic macroalgae by herbivorous fish that results in distinct bands of unvegetated sediments surrounding patch reefs. We found that benthic algal canopy height significantly increased with distance from patch reef, and that algal canopy height was positively correlated with the abundances of only one invertebrate taxon (Nematoda). Both sediment carbon to nitrogen ratios (C:N) and mean sediment particle size (μm) demonstrated a positive correlation with Nematoda and Arthropoda (predominantly copepod) abundances, respectively. These positive correlations indicate that environmental conditions are a major contributor to benthic invertebrate community distribution, acting on benthic communities in conjunction with the cascading effects of above-ground algal grazing. These results suggest that benthic communities, and the ecosystem functions they perform in this system, may be less responsive to changes in above-ground herbivorous processes than those previously studied in terrestrial systems. Understanding how above-ground organisms, and processes, affect their benthic invertebrate counterparts can shed light on how changes in aquatic communities may affect ecosystem function in previously unknown ways.

  13. Comparison of the cascadability of conventional and gain-clamped semiconductor optical amplifier gates in multi wavelength optical networks

    DEFF Research Database (Denmark)

    Wolfson, David; Stubkjær, Kristian Elmholdt

    1999-01-01

    A detailed investigation of the cascadability of Gc-soaS AND soaS in EDM networks is presented. The analysis shows far superior cascadability of GC-SOAs at a channel bit rate of 2,5 Gbit/s in systems with up to at least 16 channels.......A detailed investigation of the cascadability of Gc-soaS AND soaS in EDM networks is presented. The analysis shows far superior cascadability of GC-SOAs at a channel bit rate of 2,5 Gbit/s in systems with up to at least 16 channels....

  14. A modular architecture for multi-channel external cavity quantum cascade laser-based chemical sensors: a systems approach

    Energy Technology Data Exchange (ETDEWEB)

    Taubman, Matthew S.; Myers, Tanya L.; Bernacki, Bruce E.; Stahl, Robert D.; Cannon, Bret D.; Schiffern, John T.; Phillips, Mark C.

    2012-04-01

    A multi-channel laser-based chemical sensor platform is presented, in which a modular architecture allows the exchange of complete sensor channels without disruption to overall operation. Each sensor channel contains custom optical and electronics packages, which can be selected to access laser wavelengths, interaction path lengths and modulation techniques optimal for a given application or mission. Although intended primarily to accommodate mid-infrared (MIR) external cavity quantum cascade lasers (ECQCLs)and astigmatic Herriott cells, channels using visible or near infrared (NIR) lasers or other gas cell architectures can also be used, making this a truly versatile platform. Analog and digital resources have been carefully chosen to facilitate small footprint, rapid spectral scanning, ow-noise signal recovery, failsafe autonomous operation, and in-situ chemometric data analysis, storage and transmission. Results from the demonstration of a two-channel version of this platform are also presented.

  15. Thermal Analysis of InAs/AlSb Short Wavelength Mid-IR Quantum Cascade Lasers

    International Nuclear Information System (INIS)

    Lin, Wei; Ai-Zhen, Li; Gang-Yi, Xu

    2009-01-01

    We present the effects of hetero-interfaces and major key parameters on the thermal behaviors and performance of short wavelength mid-IR InAs/AlSb quantum cascade lasers (QCLs). We use a finite element method (FEM) with commercial software, ANSYS, to simulate the heat dissipation in QCLs in cw operation mode with an epilayer-down mounting package. The thermal performance is characterized by the temperature increase ΔT (self-heating effect) between the active region of QCLs and the heatsink. Results show that (1) the self-heating effects of InAs/AlSb QCLs are much less than those in AlInAs/GaInAs QCLs, (2) narrower ridges lead to significantly cooler active regions of InAs/AlSb QCLs due to poor heat transport in the cross-plane direction (across interfaces) and that most of the heat flows out of the active region in the lateral direction, and (3) the cavity length of the laser has little influence on the self-heating effect of the device, but the long cavity reduces mirror loss and threshold current density. (fundamental areas of phenomenology (including applications))

  16. A multifaceted trophic cascade in a detritus-based system: density-, trait-, or processing-chain-mediated effects?

    Science.gov (United States)

    Albeny-Simões, Daniel; Murrell, Ebony G; Vilela, Evaldo F; Juliano, Steven A

    2015-03-01

    We investigated three pathways by which predators on an intermediate trophic level may produce a trophic cascade in detritus-based systems. Predators may increase lower trophic levels (bacteria) by reducing density of bacteriovores, by altering behavior of bacteriovores, and by processing living bacteriovores into carcasses, feces, and dissolved nutrients that are substrates for bacteria. We tested these pathways in laboratory experiments with mosquitoes in water-filled containers. Larval Toxorhynchites rutilus prey on larval Aedes triseriatus , which feed on bacteria. Using containers stocked with oak leaf infusion as a bacterial substrate, we compared bacterial productivity at 7 and 14 days for: prey alone; prey with a predator; and prey with predation cues but no predator. Controls contained no larvae, either with predation cues or without cues. Predation cues in the control treatment increased bacterial abundance at 7 days, but this effect waned by 14 days. Aedes triseriatus larvae reduced bacterial abundance significantly at 14 days. Predator cues and real predation both eliminated the negative effect of A. triseriatus on bacterial abundance. Predation cues reduced survivorship of A. triseriatus larvae at 14 days, however this effect was smaller than the effect of real predation. We further tested effects of residues from predation as cues or as detritus in a second experiment in which A. triseriatus were killed at similar rates by: real predators ; mechanical damage without the predator and carcasses left as detritus; or mechanical damage and carcasses removed. No prey larvae were killed in controls. Bacterial productivity was greater with real predation than in all other treatments and greater when prey larvae were killed or killed and removed, than in controls. Thus we find evidence that all three pathways contribute to the trophic cascade from T. rutilus to bacteria in tree hole systems.

  17. Prevention of mother-to-child HIV transmission cascade in China: a systematic review and meta-analysis

    Science.gov (United States)

    Zeng, Huan; Chow, Eric P F; Zhao, Yong; Wang, Yang; Tang, Maozhi; Li, Leyu; Tang, Xue; Liu, Xi; Zhong, Yi; Wang, Ailing; Lo, Ying-Ru; Zhang, Lei

    2016-01-01

    Introduction The Chinese government has invested US$140 million annually on prevention of mother-to-child transmission (PMTCT) of HIV. This study evaluates the programme by examining the improvements in programme coverage HIV testing and provision of antiviral drugs along the PMTCT cascade. Methods Data for PMTCT cascade indicators were collected through a comprehensive systematic review of published peer-reviewed English and Chinese literature during 2003–2011. Meta-analysis was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Results This study included 113 publications. HIV prevalence among pregnant women in China who accessed antenatal care (ANC) remained below 0.1% during the past decade. HIV testing coverage in pregnant women attending ANC and in HIV-exposed infants at 18 months significantly increased from 62.4% (95% CI 4.7% to 98.2%) and 22.1% (16.3% to 32.3%) in 2003 to 90.3% (88.4% to 91.8%) and 82.8% (66.9% to 99.5%) in 2011 respectively, whereas antiretroviral (ARV) prophylaxis uptake increased from 35.2% (12.2% to 47.3%) and 26.9% (24.3% to 28.9%) to 86.2% (53.2% to 97.2%) and 90.3% (85.5% to 93.7%). HIV vertical transmission rate substantially decreased from 31.8% (25.7% to 38.6%) prior to the programme to 2.3% (1.4% to 3.8%) in 2011. During 2003–2011, among 25 312 (23 995–26 644) infants born to HIV-positive mothers who received ARV prophylaxis, 975 (564–1395) were diagnosed with HIV, corresponding to an average transmission rate of 3.9% (3.2% to 4.6%). However, while including transmissions among HIV-positive pregnant women who were lost along the cascade, the average transmission rate during 2003–2011 was 17.4% (15.8% to 19.0%). Conclusions PMTCT programmes have reduced HIV mother-to-child transmission in China. Further improvements in the continuum of care remain essential in realising the full potential of the programme. PMID:25935929

  18. Cascade Mountain Range in Oregon

    Science.gov (United States)

    Sherrod, David R.

    2016-01-01

    The Cascade mountain system extends from northern California to central British Columbia. In Oregon, it comprises the Cascade Range, which is 260 miles long and, at greatest breadth, 90 miles wide (fig. 1). Oregon’s Cascade Range covers roughly 17,000 square miles, or about 17 percent of the state, an area larger than each of the smallest nine of the fifty United States. The range is bounded on the east by U.S. Highways 97 and 197. On the west it reaches nearly to Interstate 5, forming the eastern margin of the Willamette Valley and, farther south, abutting the Coast Ranges. 

  19. Unlocking High-Salinity Desalination with Cascading Osmotically Mediated Reverse Osmosis: Energy and Operating Pressure Analysis.

    Science.gov (United States)

    Chen, Xi; Yip, Ngai Yin

    2018-02-20

    Current practice of using thermally driven methods to treat hypersaline brines is highly energy-intensive and costly. While conventional reverse osmosis (RO) is the most efficient desalination technique, it is confined to purifying seawater and lower salinity sources. Hydraulic pressure restrictions and elevated energy demand render RO unsuitable for high-salinity streams. Here, we propose an innovative cascading osmotically mediated reverse osmosis (COMRO) technology to overcome the limitations of conventional RO. The innovation utilizes the novel design of bilateral countercurrent reverse osmosis stages to depress the hydraulic pressure needed by lessening the osmotic pressure difference across the membrane, and simultaneously achieve energy savings. Instead of the 137 bar required by conventional RO to desalinate 70 000 ppm TDS hypersaline feed, the highest operating pressure in COMRO is only 68.3 bar (-50%). Furthermore, up to ≈17% energy saving is attained by COMRO (3.16 kWh/m 3 , compared to 3.79 kWh/m 3 with conventional RO). When COMRO is employed to boost the recovery of seawater desalination to 70% from the typical 35-50%, energy savings of up to ≈33% is achieved (2.11 kWh/m 3 , compared to 3.16 kWh/m 3 with conventional RO). Again, COMRO can operate at a moderate hydraulic pressure of 80 bar (25% lower than 113 bar of conventional RO). This study highlights the encouraging potential of energy-efficient COMRO to access unprecedented high recovery rates and treat hypersaline brines at moderate hydraulic pressures, thus extending the capabilities of membrane-based technologies for high-salinity desalination.

  20. A multi-trait systems approach reveals a response cascade to bleaching in corals.

    Science.gov (United States)

    Gardner, Stephanie G; Raina, Jean-Baptiste; Nitschke, Matthew R; Nielsen, Daniel A; Stat, Michael; Motti, Cherie A; Ralph, Peter J; Petrou, Katherina

    2017-12-07

    Climate change causes the breakdown of the symbiotic relationships between reef-building corals and their photosynthetic symbionts (genus Symbiodinium), with thermal anomalies in 2015-2016 triggering the most widespread mass coral bleaching on record and unprecedented mortality on the Great Barrier Reef. Targeted studies using specific coral stress indicators have highlighted the complexity of the physiological processes occurring during thermal stress, but have been unable to provide a clear mechanistic understanding of coral bleaching. Here, we present an extensive multi-trait-based study in which we compare the thermal stress responses of two phylogenetically distinct and widely distributed coral species, Acropora millepora and Stylophora pistillata, integrating 14 individual stress indicators over time across a simulated thermal anomaly. We found that key stress responses were conserved across both taxa, with the loss of symbionts and the activation of antioxidant mechanisms occurring well before collapse of the physiological parameters, including gross oxygen production and chlorophyll a. Our study also revealed species-specific traits, including differences in the timing of antioxidant regulation, as well as drastic differences in the production of the sulfur compound dimethylsulfoniopropionate during bleaching. Indeed, the concentration of this antioxidant increased two-fold in A. millepora after the corals started to bleach, while it decreased 70% in S. pistillata. We identify a well-defined cascading response to thermal stress, demarking clear pathophysiological reactions conserved across the two species, which might be central to fully understanding the mechanisms triggering thermally induced coral bleaching. These results highlight that bleaching is a conserved mechanism, but specific adaptations linked to the coral's antioxidant capacity drive differences in the sensitivity and thus tolerance of each coral species to thermal stress.

  1. Wastewater reuse in a cascade based system of a petrochemical industry for the replacement of losses in cooling towers.

    Science.gov (United States)

    Hansen, Everton; Rodrigues, Marco Antônio Siqueira; Aquim, Patrice Monteiro de

    2016-10-01

    This article discusses the mapping of opportunities for the water reuse in a cascade based system in a petrochemical industry in southern Brazil. This industrial sector has a large demand for water for its operation. In the studied industry, for example, approximately 24 million cubic meters of water were collected directly from the source in 2014. The objective of this study was to evaluate the implementation of the reuse of water in cascade in a petrochemical industry, focusing on the reuse of aqueous streams to replenish losses in the cooling towers. This is an industrial scale case study with real data collected during the years 2014 and 2015. Water reuse was performed using heuristic approach based on the exploitation of knowledge acquired during the search process. The methodology of work consisted of the construction of a process map identifying the stages of production and water consumption, as well as the characterization of the aqueous streams involved in the process. For the application of the industrial water reuse as cooling water, mass balances were carried out considering the maximum concentration levels of turbidity, pH, conductivity, alkalinity, calcium hardness, chlorides, sulfates, silica, chemical oxygen demand and suspended solids as parameters turbidity, pH, conductivity, alkalinity, calcium hardness, chlorides, sulfates, silica, chemical oxygen demand and suspended solids as parameters. The adopted guideline was the fulfillment of the water quality criteria for each application in the industrial process. The study showed the feasibility for the reuse of internal streams as makeup water in cooling towers, and the implementation of the reuse presented in this paper totaled savings of 385,440 m(3)/year of water, which means a sufficient volume to supply 6350 inhabitants for a period of one year, considering the average water consumption per capita in Brazil; in addition to 201,480 m(3)/year of wastewater that would no longer be generated

  2. Correlation Structure of Wavelet Cascades

    Science.gov (United States)

    Greiner, Martin; Giesemann, Jens

    The following sections are included: * Introduction * Some Basics about Wavelets * Multiresolution analysis * Dilation equations * Wavelet transformation * Multiplicative Haar-Wavelet Cascade * Binary random multiplicative branching processes * n-point correlation densities * Haar-wavelet transformed correlation densities * Daubechies-wavelet transformed correlation densities * Multiplicative Daubechies-Wavelet Cascade * Random multiplicative branching processes on a D4-wavelet tree * n-point correlation densities * Wavelet transformed correlation densities * Scaling behavior of moments * Conclusion * REFERENCES

  3. Management experiments for high-elevation agroforestry systems jointly producing matsutake mushrooms and high-quality timber in the Cascade Range of southern Oregon.

    Science.gov (United States)

    James F. Weigand

    1998-01-01

    Experimental prescriptions compare agroforestry systems designed to increase financial returns from high-elevation stands in the southern Oregon Cascade Range. The prescriptions emphasize alternative approaches for joint production of North American matsutake mushrooms (also known as North American pine mushrooms; Tricholoma magnivelare) and high-...

  4. Application of continuous stirred membrane reactor to 3-cyanopyridine bioconversion using the nitrile hydratase–amidase cascade system of Microbacterium imperiale CBS 498-74

    Czech Academy of Sciences Publication Activity Database

    Cantarella, L.; Gallifuoco, A.; Malandra, A.; Martínková, Ludmila; Pasquarelli, F.; Spera, A.; Cantarella, M.

    2010-01-01

    Roč. 47, č. 3 (2010), s. 64-70 ISSN 0141-0229 R&D Projects: GA MŠk OC09046 Institutional research plan: CEZ:AV0Z50200510 Keywords : Nitrile hydratase-amidase cascade system * 3-Cyanopyridine bioconversion * Nicotinamide Subject RIV: EE - Microbiology, Virology Impact factor: 2.287, year: 2010

  5. A feasibility analysis of replacing the standard ammonia refrigeration device with the cascade NH3/CO2 refrigeration device in the food industry

    Directory of Open Access Journals (Sweden)

    Jankovich Dennis

    2015-01-01

    Full Text Available The thermodynamic analysis demonstrates the feasibility of replacing the standard ammonia refrigeration device with the cascade NH3/CO2 refrigeration device in the food industry. The main reason for replacement is to reduce the total amount of ammonia in spaces like deep-freezing chambers, daily chambers, working rooms and technical passageways. An ammonia-contaminated area is hazardous to human health and the safety of food products. Therefore the preferred reduced amount of ammonia is accumulated in the Central Refrigeration Engine Room, where the cascade NH3/CO2 device is installed as well. Furthermore, the analysis discusses and compares two left Carnot¢s refrigeration cycles, one for the standard ammonia device and the other for the cascade NH3/CO2 device. Both cycles are processes with two-stage compression and two-stage throttling. The thermodynamic analysis demonstrates that the selected refrigeration cycle is the most cost-effective process because it provides the best numerical values for the total refrigeration factor with respect to the observed refrigeration cycle. The chief analyzed influential parameters of the cascade device are: total refrigeration load, total reactive power, mean temperature of the heat exchanger, evaporating and condensing temperature of the low-temperature part.

  6. Computation of inverse magnetic cascades

    International Nuclear Information System (INIS)

    Montgomery, D.

    1981-10-01

    Inverse cascades of magnetic quantities for turbulent incompressible magnetohydrodynamics are reviewed, for two and three dimensions. The theory is extended to the Strauss equations, a description intermediate between two and three dimensions appropriate to tokamak magnetofluids. Consideration of the absolute equilibrium Gibbs ensemble for the system leads to a prediction of an inverse cascade of magnetic helicity, which may manifest itself as a major disruption. An agenda for computational investigation of this conjecture is proposed

  7. Synthesis of a novel adaptive wavelet optimized neural cascaded steam blow-off control system for a nuclear power plant

    International Nuclear Information System (INIS)

    Malik, A.H.; Memon, A.A.; Arshad, F.

    2013-01-01

    Blow-Off System Controller (MIMO AWNN-SBOSC) is designed based on real time dynamic parametric plant data of steam blow-off system with conventional Single-Input Multi-Output Proportional plus Integral plus Derivative Controller (SIMO PIDC). The proposed MIMO AWANN-SBOSC is designed using three Multi-Input Single-Output Adaptive Wavelet Neural Network based Steam Blow-Off System Controllers (MISO AWNN-SBOSC). The hidden layer of each MISO AWNN-SBOSC is formulated using Mother Wavelet Transforms (MWT). Using nonlinear dynamic neural data of designed MIMO AWNN-SBOSC, a Multi-Input Multi-Output Adaptive Wavelet Neural Network based Steam Blow-Off System Model (MIMO AWNN-SBOSM) is developed in cascaded mode. MIMO AWNN-SBOSM is designed using two MISO AWNN-SBOSM. All training, testing and validation of MIMO AWNN-SBOSC and MIMO AWNN-SBOSM are carried out in MA TLAB while all simulation experiments are performed in Visual C. The results of the new design is evaluated against conventional controller based measured data and found robust, fast and much better in performance. (author)

  8. Fault-Tolerant Control for a Flexible Group Battery Energy Storage System Based on Cascaded Multilevel Converters

    Directory of Open Access Journals (Sweden)

    Junhong Song

    2018-01-01

    Full Text Available A flexible group battery energy storage system (FGBESS based on cascaded multilevel converters is attractive for renewable power generation applications because of its high modularity and high power quality. However, reliability is one of the most important issues and the system may suffer from great financial loss after fault occurs. In this paper, based on conventional fundamental phase shift compensation and third harmonic injection, a hybrid compensation fault-tolerant method is proposed to improve the post-fault performance in the FGBESS. By adjusting initial phase offset and amplitude of injected component, the optimal third harmonic injection is generated in an asymmetric system under each faulty operation. Meanwhile, the optimal redundancy solution under each fault condition is also elaborated comprehensively with a comparison of the presented three fault-tolerant strategies. This takes full advantage of battery utilization and minimizes the loss of energy capacity. Finally, the effectiveness and feasibility of the proposed methods are verified by results obtained from simulations and a 10 kW experimental platform.

  9. Ecological footprint analysis of environmental impacts by cascaded exploitation of diversion-type small hydropower: a case study in southwest china

    Science.gov (United States)

    Wang, Zhenhua; Li, Qingyun; Huang, Zhuo; Tang, Xianqiang; Zhao, Weihua

    2017-05-01

    Cascaded exploitation of diversion-type small hydropower (SHP) offers a source of new energy as well as socioeconomic benefits; however, it inevitably causes environmental disturbance and damage. Previous studies on the cumulative effect of cascaded diversion SHP rarely discussed using quantitative analysis method. In this paper, the ecological footprint analysis approach is proposed to assess the positive and negative impacts of cascaded diversion SHP on environment of a small-scale river in Southwest China. Positive impact is defined as ecological supply footprint (ESF), which refers to vegetation protection by replacing firewood with SHP. Negative impact is defined as ecological loss footprint (ELF), which includes fish and net primary productivity loss, vegetation destruction and soil erosion. With the raising in the number (n>4) of diversion SHP stations, the difference between ELF and ESF increases remarkably, suggesting that the adverse impacts of cascaded diversion SHP accumulate in the study area. Compared with vegetation destruction and soil erosion, the cumulative loss of fish and net productivity is the most important aspect of the adverse impacts which needs more attentions.

  10. A distributed approach for optimizing cascaded classifier topologies in real-time stream mining systems.

    Science.gov (United States)

    Foo, Brian; van der Schaar, Mihaela

    2010-11-01

    In this paper, we discuss distributed optimization techniques for configuring classifiers in a real-time, informationally-distributed stream mining system. Due to the large volume of streaming data, stream mining systems must often cope with overload, which can lead to poor performance and intolerable processing delay for real-time applications. Furthermore, optimizing over an entire system of classifiers is a difficult task since changing the filtering process at one classifier can impact both the feature values of data arriving at classifiers further downstream and thus, the classification performance achieved by an ensemble of classifiers, as well as the end-to-end processing delay. To address this problem, this paper makes three main contributions: 1) Based on classification and queuing theoretic models, we propose a utility metric that captures both the performance and the delay of a binary filtering classifier system. 2) We introduce a low-complexity framework for estimating the system utility by observing, estimating, and/or exchanging parameters between the inter-related classifiers deployed across the system. 3) We provide distributed algorithms to reconfigure the system, and analyze the algorithms based on their convergence properties, optimality, information exchange overhead, and rate of adaptation to non-stationary data sources. We provide results using different video classifier systems.

  11. CO{sub 2}-C{sub 3}H{sub 8} cascade refrigeration-heat pump system: Heat exchanger inventory optimization and its numerical verification

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharyya, Souvik [Department of Mechanical Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India); Mukhopadhyay, S. [School of Mechanical Engineering, Maurice J. Zucrow Laboratories, Purdue University, 500 Allison Road, West Lafayette, IN 47907-2014 (United States); Sarkar, J. [Department of Mechanical Engineering, Institute of Technology-BHU, Varanasi 221005 (India)

    2008-11-15

    This article presents an analytical study on the performance of a cascade refrigeration-heat pump system based on a model incorporating both internal and external irreversibilities. It further explores the optimum allocation of heat exchanger inventories in cascade refrigeration cycles for the maximization of performance and minimization of system cost. In a novel attempt, a CO{sub 2}-propane cascade system, lately showing good promise as a future solution, has been numerically simulated comprehensively incorporating precision property routines for the working fluids and this numerical model subsequently has been employed for validation of the proposed analytical model. It has been established that the total system heat exchanger inventory should be optimally divided in the ratio of a factor K between the gas cooler and the evaporator heat exchangers for maximal system output and minimal mechanical power requirement for a specified total heat exchanger inventory. It can also be construed that a similar allocation is recommended for minimization of total heat exchanger inventory with specified total system output. A strong assertion of all the analytical model results has been exhibited through a completely independent numerical system simulation. (author)

  12. Fine time course expression analysis identifies cascades of activation and repression and maps a putative regulator of mammalian sex determination.

    Directory of Open Access Journals (Sweden)

    Steven C Munger

    Full Text Available In vertebrates, primary sex determination refers to the decision within a bipotential organ precursor to differentiate as a testis or ovary. Bifurcation of organ fate begins between embryonic day (E 11.0-E12.0 in mice and likely involves a dynamic transcription network that is poorly understood. To elucidate the first steps of sexual fate specification, we profiled the XX and XY gonad transcriptomes at fine granularity during this period and resolved cascades of gene activation and repression. C57BL/6J (B6 XY gonads showed a consistent ~5-hour delay in the activation of most male pathway genes and repression of female pathway genes relative to 129S1/SvImJ, which likely explains the sensitivity of the B6 strain to male-to-female sex reversal. Using this fine time course data, we predicted novel regulatory genes underlying expression QTLs (eQTLs mapped in a previous study. To test predictions, we developed an in vitro gonad primary cell assay and optimized a lentivirus-based shRNA delivery method to silence candidate genes and quantify effects on putative targets. We provide strong evidence that Lmo4 (Lim-domain only 4 is a novel regulator of sex determination upstream of SF1 (Nr5a1, Sox9, Fgf9, and Col9a3. This approach can be readily applied to identify regulatory interactions in other systems.

  13. Attainability and minimum energy of multiple-stage cascade membrane Systems

    KAUST Repository

    Alshehri, Ali

    2015-08-12

    Process design and simulation of multi-stage membrane systems have been widely studied in many gas separation systems. However, general guidelines have not been developed yet for the attainability and the minimum energy consumption of a multi-stage membrane system. Such information is important for conceptual process design and thus it is the topic of this work. Using a well-mixed membrane model, it was determined that the attainability curve of multi-stage systems is defined by the pressure ratio and membrane selectivity. Using the constant recycle ratio scheme, the recycle ratio can shift the attainability behavior between single-stage and multi-stage membrane systems. When the recycle ratio is zero, all of the multi-stage membrane processes will decay to a single-stage membrane process. When the recycle ratio approaches infinity, the required selectivity and pressure ratio reach their absolute minimum values, which have a simple relationship with that of a single-stage membrane process, as follows: View the MathML sourceSn=S1, View the MathML sourceγn=γ1, where n is the number of stages. The minimum energy consumption of a multi-stage membrane process is primarily determined by the membrane selectivity and recycle ratio. A low recycle ratio can significantly reduce the required membrane selectivity without substantial energy penalty. The energy envelope curve can provide a guideline from an energy perspective to determine the minimum required membrane selectivity in membrane process designs to compete with conventional separation processes, such as distillation.

  14. Probabilistic sensitivity analysis of biochemical reaction systems.

    Science.gov (United States)

    Zhang, Hong-Xuan; Dempsey, William P; Goutsias, John

    2009-09-07

    Sensitivity analysis is an indispensable tool for studying the robustness and fragility properties of biochemical reaction systems as well as for designing optimal approaches for selective perturbation and intervention. Deterministic sensitivity analysis techniques, using derivatives of the system response, have been extensively used in the literature. However, these techniques suffer from several drawbacks, which must be carefully considered before using them in problems of systems biology. We develop here a probabilistic approach to sensitivity analysis of biochemical reaction systems. The proposed technique employs a biophysically derived model for parameter fluctuations and, by using a recently suggested variance-based approach to sensitivity analysis [Saltelli et al., Chem. Rev. (Washington, D.C.) 105, 2811 (2005)], it leads to a powerful sensitivity analysis methodology for biochemical reaction systems. The approach presented in this paper addresses many problems associated with derivative-based sensitivity analysis techniques. Most importantly, it produces thermodynamically consistent sensitivity analysis results, can easily accommodate appreciable parameter variations, and allows for systematic investigation of high-order interaction effects. By employing a computational model of the mitogen-activated protein kinase signaling cascade, we demonstrate that our approach is well suited for sensitivity analysis of biochemical reaction systems and can produce a wealth of information about the sensitivity properties of such systems. The price to be paid, however, is a substantial increase in computational complexity over derivative-based techniques, which must be effectively addressed in order to make the proposed approach to sensitivity analysis more practical.

  15. Chasing boundaries and cascade effects in a coupled barrier - marshes - lagoon system

    Science.gov (United States)

    Lorenzo Trueba, J.; Mariotti, G.

    2015-12-01

    Low-lying coasts are often characterized by barriers islands, shore-parallel stretches of sand separated from the mainland by marshes and lagoons. We built an exploratory numerical model to examine the morphological feedbacks within an idealized barrier - marshes -lagoon system and predict its evolution under projected rates of sea level rise and sediment supply to the backbarrier environment. Our starting point is a recently developed morphodynamic model, which couples shoreface evolution and overwash processes in a dynamic framework. As such, the model is able to capture dynamics not reproduced by morphokinematic models, which advect geometries without specific concern to processes. These dynamics include periodic barrier retreat due to time lags in the shoreface response to barrier overwash, height drowning due to insufficient overwash fluxes as sea level rises, and width drowning, which occurs when the shoreface response rate is insufficient to maintain the barrier geometry during overwash-driven landward migration. We extended the model by coupling the barrier model with a model for the evolution of the marsh platform and the boundary between the marsh and the adjacent lagoon. The coupled model explicitly describes marsh edge processes and accounts for the modification of the wave regime associated with lagoon width (fetch). Model results demonstrate that changes in factors that are not typically associated with the dynamics of coastal barriers, such as the lagoon width and the rate of export/import of sediments from and to the lagoon, can lead to previously unidentified complex responses of the coupled system. In particular, a wider lagoon in the backbarrier, and/or a reduction in the supply of muddy sediments to the backbarrier, can increase barrier retreat rates and even trigger barrier drowning. Overall, our findings highlight the importance of incorporating backbarrier dynamics in models that aim at predicting the response of barrier systems.

  16. Chasing boundaries and cascade effects in a coupled barrier-marsh-lagoon system

    Science.gov (United States)

    Lorenzo-Trueba, Jorge; Mariotti, Giulio

    2017-08-01

    The long-term dynamic evolution of an idealized barrier-marsh-lagoon system experiencing sea-level rise is studied by coupling two existing numerical models. The barrier model accounts for the interaction between shoreface dynamics and overwash flux, which allows the occurrence of barrier drowning. The marsh-lagoon model includes both a backbarrier marsh and an interior marsh, and accounts for the modification of the wave regime associated with changes in lagoon width and depth. Overwash, the key process that connects the barrier shoreface with the marsh-lagoon ecosystems, is formulated to account for the role of the backbarrier marsh. Model results show that a number of factors that are not typically associated with the dynamics of coastal barriers can enhance the rate of overwash-driven landward migration by increasing backbarrier accommodation space. For instance, lagoon deepening could be triggered by marsh edge retreat and consequent export of fine sediment via tidal dispersion, as well as by an expansion of inland marshes and consequent increase in accommodation space to be filled in with sediment. A deeper lagoon results in a larger fraction of sediment overwash being subaqueous, which coupled with a slow shoreface response sending sediment onshore can trigger barrier drowning. We therefore conclude that the supply of fine sediments to the back-barrier and the dynamics of both the interior and backbarrier marsh can be essential for maintaining the barrier system under elevated rates of sea-level rise. Our results highlight the importance of considering barriers and their associated backbarriers as part of an integrated system in which sediment is exchanged.

  17. Ecosystem services classification: A systems ecology perspective of the cascade framework

    CSIR Research Space (South Africa)

    La Notte, A

    2017-03-01

    Full Text Available processes are considered here as synonyms. Due to the utilitarian nature of ecosystem services, research and policy tend to emphasize end-use benefits rather than the underpinning ecosystem structures and processes (see ‘Traditional understanding...-centric and positivist. The ecosystem services narra- ive is part of the human system whose value is utilitarian, and its pproach reductionist and human-centered.6 A malfunction of one level can be eliminated by replacing a few components on he lower level. e.g cells...

  18. A Cascade-Based Emergency Model for Water Distribution Network

    Directory of Open Access Journals (Sweden)

    Qing Shuang

    2015-01-01

    Full Text Available Water distribution network is important in the critical physical infrastructure systems. The paper studies the emergency resource strategies on water distribution network with the approach of complex network and cascading failures. The model of cascade-based emergency for water distribution network is built. The cascade-based model considers the network topology analysis and hydraulic analysis to provide a more realistic result. A load redistribution function with emergency recovery mechanisms is established. From the aspects of uniform distribution, node betweenness, and node pressure, six recovery strategies are given to reflect the network topology and the failure information, respectively. The recovery strategies are evaluated with the complex network indicators to describe the failure scale and failure velocity. The proposed method is applied by an illustrative example. The results showed that the recovery strategy considering the node pressure can enhance the network robustness effectively. Besides, this strategy can reduce the failure nodes and generate the least failure nodes per time.

  19. Enzymatic conversion of CO2 to CH3OH via reverse dehydrogenase cascade biocatalysis: Quantitative comparison of efficiencies of immobilized enzyme systems

    DEFF Research Database (Denmark)

    Marpani, Fauziah Binti; Pinelo, Manuel; Meyer, Anne S.

    2017-01-01

    the reaction warrants innovative development. There is a particular need for development of i) better enzymes; ii) improved understanding of enzyme structure function aspects of reverse catalysis by dehydrogenases, iii) quantitative kinetic models of the enzymatic cascade reaction during simultaneous cofactor......A designed biocatalytic cascade system based on reverse enzymatic catalysis by formate dehydrogenase (EC 1.2.1.2), formaldehyde dehydrogenase (EC 1.2.1.46), and alcohol dehydrogenase (EC 1.1.1.1) can convert carbon dioxide (CO2) to methanol (CH3OH) via formation of formic acid (CHOOH......) and formaldehyde (CHOH) during equimolar cofactor oxidation of NADH to NAD+. This reaction is appealing because it represents a double gain: (1) reduction of CO2 and (2) an alternative to fossil fuel based production of CH3OH. The present review evaluates the efficiency of different immobilized enzyme systems...

  20. Abnormal cascading failure spreading on complex networks

    International Nuclear Information System (INIS)

    Wang, Jianwei; Sun, Enhui; Xu, Bo; Li, Peng; Ni, Chengzhang

    2016-01-01

    Applying the mechanism of the preferential selection of the flow destination, we develop a new method to quantify the initial load on an edge, of which the flow is transported along the path with the shortest edge weight between two nodes. Considering the node weight, we propose a cascading model on the edge and investigate cascading dynamics induced by the removal of the edge with the largest load. We perform simulated attacks on four types of constructed networks and two actual networks and observe an interesting and counterintuitive phenomenon of the cascading spreading, i.e., gradually improving the capacity of nodes does not lead to the monotonous increase in the robustness of these networks against cascading failures. The non monotonous behavior of cascading dynamics is well explained by the analysis on a simple graph. We additionally study the effect of the parameter of the node weight on cascading dynamics and evaluate the network robustness by a new metric.

  1. Cascade annealing: an overview

    International Nuclear Information System (INIS)

    Doran, D.G.; Schiffgens, J.O.

    1976-04-01

    Concepts and an overview of radiation displacement damage modeling and annealing kinetics are presented. Short-term annealing methodology is described and results of annealing simulations performed on damage cascades generated using the Marlowe and Cascade programs are included. Observations concerning the inconsistencies and inadequacies of current methods are presented along with simulation of high energy cascades and simulation of longer-term annealing

  2. Nitrous Oxide Emission Flux Measurements for Ecological Systems with an Open-Path Quantum Cascade Laser-Based Sensor

    Science.gov (United States)

    Tao, L.; Sun, K.; Cavigelli, M. A.; Gelfand, I.; Zenone, T.; Cui, M.; Miller, D. J.; Khan, M. A.; Zondlo, M. A.

    2012-12-01

    The ambient concentration of nitrous oxide (N2O), the fourth most abundant greenhouse gas, is rapidly increasing with emissions from both natural and anthropogenic sources [1]. Soil and aquatic areas are important sources and sinks for N2O due to complicated biogenic processes. However, N2O emissions are poorly constrained in space and time, despite its importance to global climate change and ozone depletion. We report our recent N2O emission measurements with an open-path quantum cascade laser (QCL)-based sensor for ecological systems. The newly emergent QCLs have been used to build compact, sensitive trace gas sensors in the mid-IR spectral region. A compact open-path QCL based sensor was developed to detect atmospheric N2O and CO at ~ 4.5 μm using wavelength modulation spectroscopy (WMS) to achieve a sensitivity of 0.26 ppbv of N2O and 0.24 ppbv of CO in 1 s with a power consumption of ~50 W [2]. This portable sensor system has been used to perform N2O emission flux measurement both with a static flux chamber and on an eddy covariance (EC) flux tower. In the flux chamber measurements, custom chambers were used to host the laser sensor, while gas samples for gas chromatograph (GC) were collected at the same time in the same chamber for validation and comparison. Different soil treatments have been applied in different chambers to study the relationship between N2O emission and the amount of fertilizer (and water) addition. Measurements from two methods agreed with each other (95% or higher confidence interval) for emission flux results, while laser sensor gave measurements with a much high temporal resolution. We have also performed the first open-path eddy covariance N2O flux measurement at Kellogg research station, Michigan State University for a month in June, 2012. Our sensor was placed on a 4-meter tower in a corn field and powered by batteries (connected with solar panels). We have observed the diurnal cycle of N2O flux. During this deployment, an inter

  3. The Paleoclimate Uncertainty Cascade: Tracking Proxy Errors Via Proxy System Models.

    Science.gov (United States)

    Emile-Geay, J.; Dee, S. G.; Evans, M. N.; Adkins, J. F.

    2014-12-01

    Paleoclimatic observations are, by nature, imperfect recorders of climate variables. Empirical approaches to their calibration are challenged by the presence of multiple sources of uncertainty, which may confound the interpretation of signals and the identifiability of the noise. In this talk, I will demonstrate the utility of proxy system models (PSMs, Evans et al, 2013, 10.1016/j.quascirev.2013.05.024) to quantify the impact of all known sources of uncertainty. PSMs explicitly encode the mechanistic knowledge of the physical, chemical, biological and geological processes from which paleoclimatic observations arise. PSMs may be divided into sensor, archive and observation components, all of which may conspire to obscure climate signals in actual paleo-observations. As an example, we couple a PSM for the δ18O of speleothem calcite to an isotope-enabled climate model (Dee et al, submitted) to analyze the potential of this measurement as a proxy for precipitation amount. A simple soil/karst model (Partin et al, 2013, 10.1130/G34718.1) is used as sensor model, while a hiatus-permitting chronological model (Haslett & Parnell, 2008, 10.1111/j.1467-9876.2008.00623.x) is used as part of the observation model. This subdivision allows us to explicitly model the transformation from precipitation amount to speleothem calcite δ18O as a multi-stage process via a physical and chemical sensor model, and a stochastic archive model. By illustrating the PSM's behavior within the context of the climate simulations, we show how estimates of climate variability may be affected by each submodel's transformation of the signal. By specifying idealized climate signals(periodic vs. episodic, slow vs. fast) to the PSM, we investigate how frequency and amplitude patterns are modulated by sensor and archive submodels. To the extent that the PSM and the climate models are representative of real world processes, then the results may help us more accurately interpret existing paleodata

  4. DC-Link Voltage Coordinated-Proportional Control for Cascaded Converter With Zero Steady-State Error and Reduced System Type

    DEFF Research Database (Denmark)

    Tian, Yanjun; Loh, Poh Chiang; Deng, Fujin

    2016-01-01

    Cascaded converter is formed by connecting two subconverters together, sharing a common intermediate dc-link voltage. Regulation of this dc-link voltage is frequently realized with a proportional-integral (PI) controller, whose high gain at dc helps to force a zero steady-state tracking error....... Such precise tracking is, however, at the expense of increasing the system type, caused by the extra pole at the origin introduced by the PI controller. The overall system may, hence, be tougher to control. To reduce the system type while preserving precise dc-link voltage tracking, this paper proposes...

  5. Stability Analysis of a Helicopter with an External Slung Load System

    OpenAIRE

    Thanapalan, Kary

    2016-01-01

    This paper describes the stability analysis of a helicopter with an underslung external load system. The Lyapunov second method is considered for the stability analysis. The system is considered as a cascade connection of uncertain nonlinear system. The stability analysis is conducted to ensure the stabilisation of the helicopter system and the positioning of the underslung load at hover condition. Stability analysis and numerical results proved that if desired condition for the stability is ...

  6. Acid-Induced Type VI Secretion System Is Regulated by ExoR-ChvG/ChvI Signaling Cascade in Agrobacterium tumefaciens

    Science.gov (United States)

    Shaw, Gwo-Chyuan; Lai, Erh-Min

    2012-01-01

    The type VI secretion system (T6SS) is a widespread, versatile protein secretion system in pathogenic Proteobacteria. Several T6SSs are tightly regulated by various regulatory systems at multiple levels. However, the signals and/or regulatory mechanisms of many T6SSs remain unexplored. Here, we report on an acid-induced regulatory mechanism activating T6SS in Agrobacterium tumefaciens, a plant pathogenic bacterium causing crown gall disease in a wide range of plants. We monitored the secretion of the T6SS hallmark protein hemolysin-coregulated protein (Hcp) from A. tumefaciens and found that acidity is a T6SS-inducible signal. Expression analysis of the T6SS gene cluster comprising the imp and hcp operons revealed that imp expression and Hcp secretion are barely detected in A. tumefaciens grown in neutral minimal medium but are highly induced with acidic medium. Loss- and gain-of-function analysis revealed that the A. tumefaciens T6SS is positively regulated by a chvG/chvI two-component system and negatively regulated by exoR. Further epistasis analysis revealed that exoR functions upstream of the chvG sensor kinase in regulating T6SS. ChvG protein levels are greatly increased in the exoR deletion mutant and the periplasmic form of overexpressed ExoR is rapidly degraded under acidic conditions. Importantly, ExoR represses ChvG by direct physical interaction, but disruption of the physical interaction allows ChvG to activate T6SS. The phospho-mimic but not wild-type ChvI response regulator can bind to the T6SS promoter region in vitro and activate T6SS with growth in neutral minimal medium. We present the first evidence of T6SS activation by an ExoR-ChvG/ChvI cascade and propose that acidity triggers ExoR degradation, thereby derepressing ChvG/ChvI to activate T6SS in A. tumefaciens. PMID:23028331

  7. Power Quality Improvement in a Cascaded Multilevel Inverter Interfaced Grid Connected System Using a Modified Inductive–Capacitive–Inductive Filter with Reduced Power Loss and Improved Harmonic Attenuation

    Directory of Open Access Journals (Sweden)

    Meenakshi Jayaraman

    2017-11-01

    Full Text Available Recently, multilevel inverters are more researched due to the advantages they offer over conventional voltage source inverters in grid connected applications. Passive filters are connected at the output of these inverters to produce sinusoidal waveforms with reduced harmonics and to satisfy grid interconnection standard requirements. This work proposes a new passive filter topology for a pulse width modulated five-level cascaded inverter interfaced grid connected system. The proposed passive filter inserts an additional resistance-capacitance branch in parallel to the filter capacitor of the traditional inductive–capacitive–inductive filter in addition to a resistance in series with it to reduce damping power loss. It can attenuate the switching frequency harmonic current components much better than the traditional filter while maintaining the same overall inductance, reduced capacitance and resistance values. The basic parameter design procedure and an approach to discover the parameters of the proposed filter is introduced. Further, a novel methodology using Particle Swarm Optimization (PSO is recommended to guarantee minimum damping loss while ensuring reduced peak during resonance. In addition, PSO algorithm is newly employed in this work to maximize harmonic attenuation in and around the switching frequency on the premise of allowable values of filter inductance and capacitance. A comparative discussion considering traditional passive filters and the proposed filter is presented and evaluated through experiments conducted on a 110 V, 1 kW five-level grid connected inverter. The modulation algorithm for the multilevel inverter is implemented using a SPARTAN 6-XC6SLX25 Field Programmable Gate Array (FPGA processor. The analysis shows that the proposed filter not only provides decreased damping power loss but also is capable of providing considerable harmonic ripple reduction in the high frequency band, improved output waveforms and lesser

  8. A modified GWO technique based cascade PI-PD controller for AGC of power systems in presence of Plug in Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Sasmita Padhy

    2017-04-01

    Full Text Available A Modified Grey Wolf Optimization (MGWO based cascade PI-PD controller is suggested in this paper for Automatic Generation Control (AGC of power systems in presence of Plug in Electric Vehicles (PEV. The modification in original Grey Wolf Optimization (GWO algorithm is introduced by strategy which maintains a proper balance between exploration and exploitation stages of the algorithm and gives more importance to the fittest wolves to find the new position of grey wolves during the iterations. Proposed algorithm is first tested using four bench mark test functions and compared with original GWO, Differential Evolution (DE, Gravitational Search Algorithm (GSA, Particle Swarm Optimization (PSO to show its superiority. The proposed technique is then used to tune various conventional controllers in a single area three-unit power system consisting of thermal hydro and gas power plants for AGC. The superiority of proposed MGWO algorithm over some recently proposed approaches has been demonstrated. In the next step, different controllers like PI, PID, and cascaded PI-PD controller are taken and Plug in Electric Vehicles (PEVs are assumed. The proposed approach is also extended to a two-area six-unit power system. Lastly, a five unequal area nonlinear power system with PEVs and dissimilar cascade PI-PD controller in each area is considered and proposed MGWO technique is employed to optimize the controller parameters in presence of nonlinearities like rate constraint of units, dead zone of governor and communication delay. It is observed that PEVs contribute in the AGC to control system frequency.

  9. Deep cascade learning

    OpenAIRE

    Marquez, Enrique, Salvador; Hare, Jonathon; Niranjan, Mahesan

    2018-01-01

    In this paper, we propose a novel approach for efficient training of deep neural networks in a bottom-up fashion using a layered structure. Our algorithm, which we refer to as Deep Cascade Learning, is motivated by the Cascade Correlation approach of Fahlman who introduced it in the context of perceptrons. We demonstrate our algorithm on networks of convolutional layers, though its applicability is more general. Such training of deep networks in a cascade, directly circumvents the well-know...

  10. Radiation induced nuclear factor kappa-B signaling cascade study in mammalian cells by improved detection systems

    Science.gov (United States)

    Chishti, Arif Ali; Baumstark-Khan, Christa; Hellweg, Christine; Reitz, Guenther

    To enable long-term human space flight cellular radiation response to densely ionizing radiation needs to be better understood for developing appropriate countermeasures to mitigate acute effects and late radiation risks for the astronaut. The biological effectiveness of accelerated heavy ions with high linear energy transfer (LET) for effecting DNA damage response pathways as a gateway to cell death or survival is of major concern, not only for tumor radiotherapy but also for new regimes of space missions. Ionizing radiation modulates several signaling pathways resulting in transcription factor activation. NF-kappaB is one of the important transcription factors that respond to changes in the environment of a mammalian cell and plays a key role in many biological processes relevant to radiation response, such as apoptosis, inflammation and carcinogenesis. From medical and biological point of view it is important to understand radiation induced NF-kappaB signaling cascade. For studying NF-kappaB signaling, green fluorescent proteins EGFP and d2EGFP were used previously (Advances in Space Research, 36: 1673-1679, 2005). The current study aims to improve reporter assays by the use of a destabilized variant of red fluorescent protein tdTomato (DD-tdTomato) which gives high fluorescence signals and a better signal/noise ratio for NF-kappaB activation. The reporter system HEK-pNFkappaB-DD-tdTomato-C8 is a dual reporter system which can provide both discrete and cumulative signals after exposure to ionizing radiation (X-rays, heavy ions). In the presence of Shield-1, the fluorescent protein DD-tdTomato is not degraded but accumulated inside the cell which helps to quantify the fold induction of NF-kappaB-dependent gene expression. The minimum dose required to activate NF-kappaB is 6 Gy but accumulated signals data shows that NF-kappaB is activated after 3 Gy in the presence of Shield-1. Average dose and number of heavy ions’ hits per nucleus necessary to double the NF

  11. Experimental evaluation of a cascade refrigeration system prototype with CO{sub 2} and NH{sub 3} for freezing process applications

    Energy Technology Data Exchange (ETDEWEB)

    Dopazo, J. Alberto; Fernandez-Seara, Jose [Area de Maquinas y Motores Termicos, E.T.S. de Ingenieros Industriales, University of Vigo, Campus Lagoas-Marcosende No 9, 36310 Vigo (Spain)

    2011-01-15

    A prototype of a cascade refrigeration system using NH{sub 3} and CO{sub 2} as refrigerants has been designed and built. The prototype is used to supply a 9 kW refrigeration capacity horizontal plate freezer at an evaporating temperature of -50 C as design conditions. The prototype includes a specific control system and a data acq*uisition system. The experimental evaluation started with the real conditions within the design operating parameters. Subsequently, several tests were performed fixing four CO{sub 2} evaporating temperatures (-50, -45, -40 and -35 C). At each one of the evaporating temperatures evaluated, the CO{sub 2} condensing temperature was varied from -17.5 to -7.5 C and an experimental optimum value of CO{sub 2} condensing temperature was determined. The discussions on the experimental results include the influence of the operating parameters on the cascade system's performance. In addition, the experimental results are compared with two common double stage refrigeration systems using NH{sub 3} as refrigerant. (author)

  12. Hierarchical energy management system for stand-alone hybrid system based on generation costs and cascade control

    International Nuclear Information System (INIS)

    Torreglosa, J.P.; García, P.; Fernández, L.M.; Jurado, F.

    2014-01-01

    Highlights: • We present an energy management system for a stand-alone WT/PV/hydrogen/battery hybrid system. • Hierarchical control composed by master and slave control strategies. • Control assures reliable electricity support for stand-alone applications subject to technical and economic criteria. - Abstract: This paper presents an energy management system (EMS) for stand-alone hybrid systems composed by photovoltaic (PV) solar panels and a wind turbine (WT) as primary energy sources and two energy storage systems, which are a hydrogen system and a battery. The hydrogen system is composed of fuel cell (FC), electrolyzer and hydrogen storage tank. The EMS is a hierarchical control composed by a master control strategy and a slave control strategy. On the one hand, the master control generates the reference powers to meet several premises (such as to satisfy the load power demand, and to maintain the hydrogen tank level and the state of charge (SOC) of the battery between their target margins), taking also into account economic aspects to discriminate between using the battery or hydrogen system. On the other hand, the slave control modifies the reference powers generated by the master control according to the energy sources dynamic limitations, and maintains the DC bus voltage at its reference value. The models, implemented in MATLAB-Simulink environment, have been developed from commercially available components. To check the viability of the proposed EMS, two kinds of simulations were carried out: (1) A long-term simulation of 25 years (expected lifetime of the system) with a sample time of one hour to validate the master control of the EMS; and (2) A short-term simulation with sudden net power variations to validate the slave control of the EMS

  13. Systems engineering and analysis

    CERN Document Server

    Blanchard, Benjamin S

    2010-01-01

    For senior-level undergraduate and first and second year graduate systems engineering and related courses. A total life-cycle approach to systems and their analysis. This practical introduction to systems engineering and analysis provides the concepts, methodologies, models, and tools needed to understand and implement a total life-cycle approach to systems and their analysis. The authors focus first on the process of bringing systems into being--beginning with the identification of a need and extending that need through requirements determination, functional analysis and allocation, design synthesis, evaluation, and validation, operation and support, phase-out, and disposal. Next, the authors discuss the improvement of systems currently in being, showing that by employing the iterative process of analysis, evaluation, feedback, and modification, most systems in existence can be improved in their affordability, effectiveness, and stakeholder satisfaction.

  14. Cascaded automatic target recognition (Cascaded ATR)

    Science.gov (United States)

    Walls, Bradley

    2010-04-01

    The global war on terror has plunged US and coalition forces into a battle space requiring the continuous adaptation of tactics and technologies to cope with an elusive enemy. As a result, technologies that enhance the intelligence, surveillance, and reconnaissance (ISR) mission making the warfighter more effective are experiencing increased interest. In this paper we show how a new generation of smart cameras built around foveated sensing makes possible a powerful ISR technique termed Cascaded ATR. Foveated sensing is an innovative optical concept in which a single aperture captures two distinct fields of view. In Cascaded ATR, foveated sensing is used to provide a coarse resolution, persistent surveillance, wide field of view (WFOV) detector to accomplish detection level perception. At the same time, within the foveated sensor, these detection locations are passed as a cue to a steerable, high fidelity, narrow field of view (NFOV) detector to perform recognition level perception. Two new ISR mission scenarios, utilizing Cascaded ATR, are proposed.

  15. Detailed theoretical investigation and comparison of the cascadability of conventional and gain-clamped SOA gates in multi wavelength optical networks

    DEFF Research Database (Denmark)

    Wolfson, David

    1999-01-01

    A detailed theoretical investigation of the cascadability of GC-SOAs and SOAs in WDM networks is presented. The analysis shows that the cascadability of SOAs is limited by degradation of both extinction ratio and ASE accumulation, whereas the cascadability for GC-SOAs mainly is limited...... by an accumulation af ASE. This result is superior cascadability of GC-SOAs at a channel bit rate of 2,5 Gbit/s in systems with up to at least 16 channels even when compared to short cavity SOA gates....

  16. State of Charge Balancing Control of a Multi-Functional Battery Energy Storage System Based on a 11-Level Cascaded Multilevel PWM Converter

    DEFF Research Database (Denmark)

    Wang, Songcen; Teodorescu, Remus; Máthé, Lászlo

    2015-01-01

    This paper focuses on modeling and SOC (State of Charge) balancing control of lithium-ion battery energy storage system based on cascaded multilevel converter for both grid integration and electric vehicle propulsion applications. The equivalent electrical circuit model of lithium-ion battery...... module is established based on the relationship between SOC (State of Charge) and OCV (Open Circuit Voltage) which is obtained from the battery charge and discharge test curves. A hierarchical control structure is proposed to realize different operating modes. The decoupled current control scheme...

  17. A Study of the Impact of Peak Demand on Increasing Vulnerability of Cascading Failures to Extreme Contingency Events

    Energy Technology Data Exchange (ETDEWEB)

    Vyakaranam, Bharat GNVSR; Vallem, Mallikarjuna R.; Nguyen, Tony B.; Samaan, Nader A.; Berscheid, Alan P.; Makarov, Yuri V.; Diao, Ruisheng

    2017-10-02

    The vulnerability of large power systems to cascading failures and major blackouts has become evident since the Northeast blackout in 1965. Based on analyses of the series of cascading blackouts in the past decade, the research community realized the urgent need to develop better methods, tools, and practices for performing cascading-outage analysis and for evaluating mitigations that are easily accessible by utility planning engineers. PNNL has developed the Dynamic Contingency Analysis Tool (DCAT) as an open-platform and publicly available methodology to help develop applications that aim to improve the capabilities of power planning engineers to assess the impact and likelihood of extreme contingencies and potential cascading events across their systems and interconnections. DCAT analysis will help identify potential vulnerabilities and allow study of mitigation solutions to reduce the risk of cascading outages in technically sound and effective ways. Using the DCAT capability, we examined the impacts of various load conditions to identify situations in which the power grid may encounter cascading outages that could lead to potential blackouts. This paper describes the usefulness of the DCAT tool and how it helps to understand potential impacts of load demand on cascading failures on the power system.

  18. Efficiency Analysis of the access method with the cascading Bloom filter to the data warehouse on the parallel computing platform

    Science.gov (United States)

    Grigoriev, Yu A.; Proletarskaya, V. A.; Ermakov, E. Yu; Ermakov, O. Yu

    2017-10-01

    A new method was developed with a cascading Bloom filter (CBF) for executing SQL queries in the Apache Spark parallel computing environment. It includes the representation of the original query in the form of several subqueries, the development of a connection graph and the transformation of subqueries, the definition of connections where it is necessary to use Bloom filters, the representation of the graph in terms of Spark. On the example of the query Q3 of the TPC-H test, full-scale experiments were carried out, which confirmed the effectiveness of the developed method.

  19. DNA binding properties of the small cascade subunit Csa5.

    Directory of Open Access Journals (Sweden)

    Michael Daume

    Full Text Available CRISPR-Cas systems provide immunity against viral attacks in archaeal and bacterial cells. Type I systems employ a Cas protein complex termed Cascade, which utilizes small CRISPR RNAs to detect and degrade the exogenic DNA. A small sequence motif, the PAM, marks the foreign substrates. Previously, a recombinant type I-A Cascade complex from the archaeon Thermoproteus tenax was shown to target and degrade DNA in vitro, dependent on a native PAM sequence. Here, we present the biochemical analysis of the small subunit, Csa5, of this Cascade complex. T. tenax Csa5 preferentially bound ssDNA and mutants that showed decreased ssDNA-binding and reduced Cascade-mediated DNA cleavage were identified. Csa5 oligomerization prevented DNA binding. Specific recognition of the PAM sequence was not observed. Phylogenetic analyses identified Csa5 as a universal member of type I-A systems and revealed three distinct groups. A potential role of Csa5 in R-loop stabilization is discussed.

  20. Fiscal system analysis - contractual systems

    International Nuclear Information System (INIS)

    Kaiser, M.J.

    2006-01-01

    Production sharing contracts are one of the most popular forms of contractual system used in petroleum agreements around the world, but the manner in which the fiscal terms and contract parameters impact system measures is complicated and not well understood. The purpose of this paper is to quantify the influence of private and market uncertainty in contractual fiscal systems. A meta-modelling approach is employed that couples the results of a simulation model with regression analysis to construct numerical functionals that quantify the fiscal regime. Relationships are derived that specify how the present value, rate of return, and take statistics vary as a function of the system parameters. The deepwater Girassol field development in Angola is taken as a case study. (author)

  1. Cascade: a Knowledge-Based System Supporting Shoe Depths Selection and Casing Design CASCADE : un système à base de connaissances pour l'aide au choix de la profondeur des sabots et à la conception du tubage

    Directory of Open Access Journals (Sweden)

    Sansone A.

    2006-11-01

    Full Text Available CASCADE is a decisional support system for shoe depth selection and casing design in exploration and production wells. This expert system is part of the ADIS project (Advanced Drilling Information System, jointly developed by three ENI companies : AGIP, ENIDATA, SAIPEM. The purpose of ADIS is to provide drilling engineering software tools for well planning and drilling operations support both at the office and rig site, to monitor real time operations and to diagnose drilling problems. To support real-time operations, ADIS project team developed tools for satellite communication between rigs and districts or headquarters, and expert systems to monitor operations, such as the status analyzer, on-line pressure gradients forecasts, alarms monitoring and management. The communication between different applications is provided by databases, both for the real time and the off line parts. The real time database is volatile; measurements are recorded on micrologs, which are in due time stored in the permanent, off line relational database for future use. Therefore, ADIS will provide better operations support and improved accuracy in well planning, with the ultimate aim of reducing risks and costs. CASCADE is part of the well planning tools developed for ADIS project: other software tools are related to directional well planning, hydraulics modelling, temperature prediction and gradients forecast. Casing shoe depth selection, and the consequent determination of geometrical and mechanical characteristics of casings, is a crucial activity. It heavily influences well planning and affects both safety and economical aspects of drilling operations. Accurate well and casing design can significantly reduce drilling costs and risks. Currently, casing design is carried out according to several requirements : company standards, common practice procedures, drilling engineers' experience and local regulations. Therefore, the choice of the best casing parameters which

  2. Mechanisms of cascade collapse

    International Nuclear Information System (INIS)

    Diaz de la Rubia, T.; Smalinskas, K.; Averback, R.S.; Robertson, I.M.; Hseih, H.; Benedek, R.

    1988-12-01

    The spontaneous collapse of energetic displacement cascades in metals into vacancy dislocation loops has been investigated by molecular dynamics (MD) computer simulation and transmission electron microscopy (TEM). Simulations of 5 keV recoil events in Cu and Ni provide the following scenario of cascade collapse: atoms are ejected from the central region of the cascade by replacement collision sequences; the central region subsequently melts; vacancies are driven to the center of the cascade during resolidification where they may collapse into loops. Whether or not collapse occurs depends critically on the melting temperature of the metal and the energy density and total energy in the cascade. Results of TEM are presented in support of this mechanism. 14 refs., 4 figs., 1 tab

  3. Node vulnerability of water distribution networks under cascading failures

    International Nuclear Information System (INIS)

    Shuang, Qing; Zhang, Mingyuan; Yuan, Yongbo

    2014-01-01

    Water distribution networks (WDNs) are important in modern lifeline system. Its stability and reliability are critical for guaranteeing high living quality and continuous operation of urban functions. The aim of this paper is to evaluate the nodal vulnerability of WDNs under cascading failures. Vulnerability is defined to analyze the effects of the consequent failures. A cascading failure is a step-by-step process which is quantitatively investigated by numerical simulation with intentional attack. Monitored pressures in different nodes and flows in different pipes have been used to estimate the network topological structure and the consequences of nodal failure. Based on the connectivity loss of topological structure, the nodal vulnerability has been evaluated. A load variation function is established to record the nodal failure reason and describe the relative differences between the load and the capacity. The proposed method is validated by an illustrative example. The results revealed that the network vulnerability should be evaluated with the consideration of hydraulic analysis and network topology. In the case study, 70.59% of the node failures trigger the cascading failures with different failure processes. It is shown that the cascading failures result in severe consequences in WDNs. - Highlights: • The aim of this paper is to evaluate the nodal vulnerability of water distribution networks under cascading failures. • Monitored pressures and flows have been used to estimate the network topological structure and the consequences of nodal failure. • Based on the connectivity loss of topological structure, the nodal vulnerability has been evaluated. • A load variation function is established to record the failure reason and describe the relative differences between load and capacity. • The results show that 70.59% of the node failures trigger the cascading failures with different failure processes

  4. Application of heated inlet extensions to the TSI 3306/3321 system: comparison with the Andersen cascade impactor and next generation impactor.

    Science.gov (United States)

    Myrdal, Paul B; Mogalian, Erik; Mitchell, Jolyon; Nagel, Mark; Wright, Charlie; Kiser, Brent; Prell, Mark; Woessner, Mike; Stein, Stephen W

    2006-01-01

    Pharmaceutical aerosol size distribution analysis based on multi-stage inertial impaction is well accepted, though laborious. The TSI 3306 Impactor Inlet/3321 time-of-flight (TOF) Aerodynamic Particle Size Analyzer (APS) has been evaluated for its ease of use and potential for time savings during product development. However, instrument inlet modifications may be necessary for increased correlation with equivalent measurements obtained by inertial impaction following pharmacopeial methods. A heated inlet extension tube was located between the USP/Ph.Eur. throat and the Single-Stage Impactor (SSI) to promote evaporation of residual ethanol from aerosol droplets, generated from two formulations containing ethanol as semi-volatile solubilizer (8 and 20% w/w) for the active pharmaceutical ingredient. As temperature and extension length increased, the SSI-measured fine particle fraction (aerosol < 4.7 microm aerodynamic diameter) also increased, for the aerosols used in this study. These values correlated quite closely with equivalent measures made by multi-stage cascade impactor equipped with the same throat. Particle size distribution profiles measured with the APS for either formulation did not significantly change utilizing the heated extensions, suggesting that ethanol evaporation was largely complete at any condition by the time the aerosol entered the measurement zone of the TOF analyzer. The addition of a heated inlet extension may be useful to facilitate evaporation of residual semi-volatile species, especially when an agreement of APS-derived particle size mass distribution data from the SSI with multi-stage cascade impactors is desired. However, complete evaporation of the semi-volatile species may not be necessary for SSI-generated mass distribution to match conventionally used cascade impactors.

  5. Cas5d Protein Processes Pre-crRNA and Assembles into a Cascade-like Interference Complex in Subtype I-C/Dvulg CRISPR-Cas System

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Ki Hyun; Haitjema, Charles; Liu, Xueqi; Ding, Fran; Wang, Hongwei; DeLisa, Matthew P.; Ke, Ailong (Yale); (Cornell); (Tsinghua)

    2012-10-10

    Clustered regularly interspaced short palindromic repeats (CRISPRs), together with an operon of CRISPR-associated (Cas) proteins, form an RNA-based prokaryotic immune system against exogenous genetic elements. Cas5 family proteins are found in several type I CRISPR-Cas systems. Here, we report the molecular function of subtype I-C/Dvulg Cas5d from Bacillus halodurans. We show that Cas5d cleaves pre-crRNA into unit length by recognizing both the hairpin structure and the 3 single stranded sequence in the CRISPR repeat region. Cas5d structure reveals a ferredoxin domain-based architecture and a catalytic triad formed by Y46, K116, and H117 residues. We further show that after pre-crRNA processing, Cas5d assembles with crRNA, Csd1, and Csd2 proteins to form a multi-sub-unit interference complex similar to Escherichia coli Cascade (CRISPR-associated complex for antiviral defense) in architecture. Our results suggest that formation of a crRNA-presenting Cascade-like complex is likely a common theme among type I CRISPR subtypes.

  6. The HIV Care Cascade and sub-analysis of those linked to but not retained in care: the experience from a tertiary HIV referral service in Dublin Ireland.

    Science.gov (United States)

    McGettrick, P; Ghavami-Kia, B; Tinago, W; Macken, A; O'Halloran, J; Lambert, J S; Sheehan, G; Mallon, P W G

    2017-05-01

    The HIV Care Cascade model can be used to measure how clinical services align with United Nations' (UN) HIV treatment targets. Previous models have highlighted sequential losses at each step of the Cascade with a significant proportion being not retained in care (NRIC). We aimed to assess the feasibility of meeting the UN targets and assess factors associated with, and calculate the true proportion of those, NRIC. All people living with HIV who were linked to our service, one of three specialist HIV care providers in Dublin Ireland, from its establishment in 1993 to 1 December 2014, were included in the cohort and were categorized as linked to care, retained in care (RIC), on antiretroviral therapy (on ART), virally suppressed (HIV RNA <40copies/ml), and NRIC. An analysis of those NRIC was performed to categorize their current status through direct/indirect contact. Of 1000 patients linked to care, 78.7% (n = 787) were RIC, of whom 91.5% (n = 720) were on ART, with 89.9% (n = 644) virally suppressed. Those RIC were more likely older (p = 0.006) and non-IVDU (p < 0.001). Of 213 (21.3%) NRIC, 56 (26.3%) emigrated, 27 (12.7%) transferred care, 15 (7.0%) stopped attending but were contactable, 38 (17.8%) died, and 77 (36.1%) were lost to follow-up. After revision, 10.5% of the cohort was confirmed as NRIC, with 6 of 15 defined as "stopped attending" re-linked to care following direct contact. Our HIV Care Cascade model demonstrates that the true numbers of patients NRIC may be significantly lower than previously estimated and once RIC, treatment goals approaching the United Nations Programme on HIV and AIDS targets are possible with 91.5% on treatment and almost 90% of those on treatment virally suppressed. That 40% reengaged following direct contact suggests benefit through regular monitoring and direct contact based on the HIV Care Cascade model.

  7. Bankruptcy cascades in interbank markets.

    Directory of Open Access Journals (Sweden)

    Gabriele Tedeschi

    Full Text Available We study a credit network and, in particular, an interbank system with an agent-based model. To understand the relationship between business cycles and cascades of bankruptcies, we model a three-sector economy with goods, credit and interbank market. In the interbank market, the participating banks share the risk of bad debits, which may potentially spread a bank's liquidity problems through the network of banks. Our agent-based model sheds light on the correlation between bankruptcy cascades and the endogenous economic cycle of booms and recessions. It also demonstrates the serious trade-off between, on the one hand, reducing risks of individual banks by sharing them and, on the other hand, creating systemic risks through credit-related interlinkages of banks. As a result of our study, the dynamics underlying the meltdown of financial markets in 2008 becomes much better understandable.

  8. Bankruptcy cascades in interbank markets.

    Science.gov (United States)

    Tedeschi, Gabriele; Mazloumian, Amin; Gallegati, Mauro; Helbing, Dirk

    2012-01-01

    We study a credit network and, in particular, an interbank system with an agent-based model. To understand the relationship between business cycles and cascades of bankruptcies, we model a three-sector economy with goods, credit and interbank market. In the interbank market, the participating banks share the risk of bad debits, which may potentially spread a bank's liquidity problems through the network of banks. Our agent-based model sheds light on the correlation between bankruptcy cascades and the endogenous economic cycle of booms and recessions. It also demonstrates the serious trade-off between, on the one hand, reducing risks of individual banks by sharing them and, on the other hand, creating systemic risks through credit-related interlinkages of banks. As a result of our study, the dynamics underlying the meltdown of financial markets in 2008 becomes much better understandable.

  9. Biocatalysis: Chiral cascades

    Science.gov (United States)

    Wang, Jian-Bo; Reetz, Manfred T.

    2015-12-01

    Racemic or enantiomerically pure alcohols can be converted with high yield into enantiopure chiral amines in a one-pot redox-neutral cascade process by the clever combination of an alcohol dehydrogenase and an appropriate amine dehydrogenase.

  10. Conjugation of cascades

    International Nuclear Information System (INIS)

    San Martin, Jesus; Rodriguez-Perez, Daniel

    2009-01-01

    Presented in this work are some results relative to sequences found in the logistic equation bifurcation diagram, which is the unimodal quadratic map prototype. All of the different saddle-node bifurcation cascades, associated with every last appearance p-periodic orbit (p=3,4,5,...), can also be generated from the very Feigenbaum cascade. In this way it is evidenced the relationship between both cascades. The orbits of every saddle-node bifurcation cascade, mentioned above, are located in different chaotic bands, and this determines a sequence of orbits converging to every band-merging Misiurewicz point. In turn, these accumulation points form a sequence whose accumulation point is the Myrberg-Feigenbaum point. It is also proven that the first appearance orbits in the n-chaotic band converge to the same point as the last appearance orbits of the (n + 1)-chaotic band. The symbolic sequences of band-merging Misiurewicz points are computed for any window.

  11. Learning optimal embedded cascades.

    Science.gov (United States)

    Saberian, Mohammad Javad; Vasconcelos, Nuno

    2012-10-01

    The problem of automatic and optimal design of embedded object detector cascades is considered. Two main challenges are identified: optimization of the cascade configuration and optimization of individual cascade stages, so as to achieve the best tradeoff between classification accuracy and speed, under a detection rate constraint. Two novel boosting algorithms are proposed to address these problems. The first, RCBoost, formulates boosting as a constrained optimization problem which is solved with a barrier penalty method. The constraint is the target detection rate, which is met at all iterations of the boosting process. This enables the design of embedded cascades of known configuration without extensive cross validation or heuristics. The second, ECBoost, searches over cascade configurations to achieve the optimal tradeoff between classification risk and speed. The two algorithms are combined into an overall boosting procedure, RCECBoost, which optimizes both the cascade configuration and its stages under a detection rate constraint, in a fully automated manner. Extensive experiments in face, car, pedestrian, and panda detection show that the resulting detectors achieve an accuracy versus speed tradeoff superior to those of previous methods.

  12. Current Decoupling Control Strategy of Medium Voltage Cascaded Multilevel STATCOM

    Directory of Open Access Journals (Sweden)

    Zhao Xuehua

    2014-10-01

    Full Text Available As one of effective regulation methods, static synchronous compensator (STATCOM has been widespread used to regulate dynamic reactive power and solve dynamic voltage stability problems into power-grid. Through the analysis of mathematical model, cascaded STATCOM, which is constructed by several cascaded H-bridges, is a nonlinear, multivariable, strongly coupled system. It will make difficulties in the design and practical application of controller. In this paper, mathematical models of cascaded STATCOM in a -b- c and d-q coordinates are deduced. Based on the theory of internal model control and PI control strategy, the internal decoupling control algorithm is introduced to realize independent control of active current and reactive current. At the same time, decoupling control algorithms are designed and decoupling control models are given and simulated. From the combined circuit topology and control with multi-FPGA, the simulation and experimental platform of cascaded SVG, which use the control algorithms of double-loop control with the current inner loop and capacitor voltage outer loop. Both in a-b-c coordinates and d-q-0 coordinates, experiment and simulation results show that three-phase current of STATCOM has good tracking performance and control precision, which show the regulator design method and parameters setting are feasible and effective.

  13. A design of cascade control system and adaptive load compensator for battery/ultracapacitor hybrid energy storage-based direct current microgrid

    International Nuclear Information System (INIS)

    Pavković, Danijel; Lobrović, Mihael; Hrgetić, Mario; Komljenović, Ante

    2016-01-01

    Highlights: • Battery/ultracapacitor storage is considered for a direct-current microgrid. • Microgrid voltage cascade control system with load compensator is designed. • Current references are allocated so that ultracapacitor takes on transient loads. • Adaptive Kalman filter-based estimator is used for indirect load compensation. • Control strategy has been verified on a downscaled hardware-in-the-loop setup. - Abstract: A control system design based on an actively-controlled battery/ultracapacitor hybrid energy storage system suitable for direct current microgrid energy management purposes is presented in this paper. The proposed cascade control system arrangement is based on the superimposed proportional–integral voltage controller designed according to Damping Optimum criterion and a zero-pole canceling feed-forward load compensator aimed at voltage excursion suppression under variable load conditions. The superimposed controller commands the inner battery and ultracapacitor current control loops through a dynamic current reference distribution scheme, wherein the ultracapacitor takes on the highly-dynamic (transient) current demands, and the battery covers for steady-state loads. In order to avoid deep discharges of the ultracapacitor module, it is equipped with an auxiliary state-of-charge controller. Finally, for those applications where load is not measured, an adaptive Kalman filter-based load compensator is proposed and tested. The presented control strategy has been implemented on the low-cost industrial controller unit, and its effectiveness has been verified by means of simulations and experiments for the cases of abrupt load changes and quasi-stochastic load profiles using a downscaled battery/ultracapacitor hardware-in-the-loop experimental setup.

  14. Optimization of a cascade refrigeration system using refrigerant C3H8 in high temperature circuits (HTC) and a mixture of C2H6/CO2 in low temperature circuits (LTC)

    International Nuclear Information System (INIS)

    Nasruddin; Sholahudin, S.; Giannetti, N.; Arnas

    2016-01-01

    Highlights: • Multi-objective optimization is conducted in the cascade refrigeration system. • Combination of operating temperature and refrigerant performance has been studied. • Characteristic of C 3 H 8 and a mixture of C 2 H 6 /CO 2 have been investigated. • Determining of CO 2 fraction to optimize refrigeration system has been done. - Abstract: This paper discusses the multi-objectives optimization of a cascade refrigeration system using refrigerant C 3 H 8 in high temperature circuits (HTC) and a mixture of C 2 H 6 /CO 2 in low temperature circuits (LTC). The evaporator temperature, condenser temperature, C 2 H 6 /CO 2 mixture condensation temperature, cascade temperature differences, and the CO 2 mass fraction are chosen as the decision variables. Whereas cooling capacity, cold space temperature, and ambient temperature are taken as the constraints. The purpose of this research is to design a cascade refrigeration system whose optimum performance are defined in terms of economics and thermodynamics. Accordingly, there are two objective functions that should be simultaneously optimized including the total annual cost which consists of the capital and operational cost and the total exergy destruction of the system. To this aim, the optimum operating temperature of the system and CO 2 fraction should be determined so that the system has minimum exergy destruction and annual cost. Results show that, the optimum value of the decision variables for this system can be determined by trade-off between annual cost and exergy destruction.

  15. Cascade of links in complex networks

    International Nuclear Information System (INIS)

    Feng, Yeqian; Sun, Bihui; Zeng, An

    2017-01-01

    Cascading failure is an important process which has been widely used to model catastrophic events such as blackouts and financial crisis in real systems. However, so far most of the studies in the literature focus on the cascading process on nodes, leaving the possibility of link cascade overlooked. In many real cases, the catastrophic events are actually formed by the successive disappearance of links. Examples exist in the financial systems where the firms and banks (i.e. nodes) still exist but many financial trades (i.e. links) are gone during the crisis, and the air transportation systems where the airports (i.e. nodes) are still functional but many airlines (i.e. links) stop operating during bad weather. In this letter, we develop a link cascade model in complex networks. With this model, we find that both artificial and real networks tend to collapse even if a few links are initially attacked. However, the link cascading process can be effectively terminated by setting a few strong nodes in the network which do not respond to any link reduction. Finally, a simulated annealing algorithm is used to optimize the location of these strong nodes, which significantly improves the robustness of the networks against the link cascade. - Highlights: • We propose a link cascade model in complex networks. • Both artificial and real networks tend to collapse even if a few links are initially attacked. • The link cascading process can be effectively terminated by setting a few strong nodes. • A simulated annealing algorithm is used to optimize the location of these strong nodes.

  16. Cascade of links in complex networks

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Yeqian; Sun, Bihui [Department of Management Science, School of Government, Beijing Normal University, 100875 Beijing (China); Zeng, An, E-mail: anzeng@bnu.edu.cn [School of Systems Science, Beijing Normal University, 100875 Beijing (China)

    2017-01-30

    Cascading failure is an important process which has been widely used to model catastrophic events such as blackouts and financial crisis in real systems. However, so far most of the studies in the literature focus on the cascading process on nodes, leaving the possibility of link cascade overlooked. In many real cases, the catastrophic events are actually formed by the successive disappearance of links. Examples exist in the financial systems where the firms and banks (i.e. nodes) still exist but many financial trades (i.e. links) are gone during the crisis, and the air transportation systems where the airports (i.e. nodes) are still functional but many airlines (i.e. links) stop operating during bad weather. In this letter, we develop a link cascade model in complex networks. With this model, we find that both artificial and real networks tend to collapse even if a few links are initially attacked. However, the link cascading process can be effectively terminated by setting a few strong nodes in the network which do not respond to any link reduction. Finally, a simulated annealing algorithm is used to optimize the location of these strong nodes, which significantly improves the robustness of the networks against the link cascade. - Highlights: • We propose a link cascade model in complex networks. • Both artificial and real networks tend to collapse even if a few links are initially attacked. • The link cascading process can be effectively terminated by setting a few strong nodes. • A simulated annealing algorithm is used to optimize the location of these strong nodes.

  17. Cascade orificial resistive device

    Science.gov (United States)

    Bitsakis, Nicholas; Cassidy, James

    1994-07-01

    A cascade orificial resistive device for throttling fluid flow which minimizes acoustic noise and internal vibrations is described herein. The device has a hollow body defining a fluid passageway, a plurality of perforated plates mounted within the passageway, a fixed end ring adjacent one end of the perforated plates, and a threadable end ring adjacent an opposite end of the perforated plates to place the plates in compression. Each of the perforated plates is a single piece molded plate having an integral outer ring and an integrally formed center keying mechanism as well as a plurality of orifices. The keying mechanism formed on each plate is designed so that adjacent ones of the plates have their orifices misaligned. In this manner, a pressure drop across each plate is created and the fluid flow through the device is throttled. The device of the present invention has utility in a number of onboard marine vessel systems wherein reduced acoustic noise and internal vibrations are particularly desirable.

  18. Realization of a Cascaded Quantum System: Heralded Absorption of a Single Photon Qubit by a Single-Electron Charged Quantum Dot.

    Science.gov (United States)

    Delteil, Aymeric; Sun, Zhe; Fält, Stefan; Imamoğlu, Atac

    2017-04-28

    Photonic losses pose a major limitation for the implementation of a quantum state transfer between nodes of a quantum network. A measurement that heralds a successful transfer without revealing any information about the qubit may alleviate this limitation. Here, we demonstrate the heralded absorption of a single photonic qubit, generated by a single neutral quantum dot, by a single-electron charged quantum dot that is located 5 m away. The transfer of quantum information to the spin degree of freedom takes place upon the emission of a photon; for a properly chosen or prepared quantum dot, the detection of this photon yields no information about the qubit. We show that this process can be combined with local operations optically performed on the destination node by measuring classical correlations between the absorbed photon color and the final state of the electron spin. Our work suggests alternative avenues for the realization of quantum information protocols based on cascaded quantum systems.

  19. Thermal surveillance of Cascade Range volcanoes using ERTS-1 multispectral scanner, aircraft imaging systems, and ground-based data communication platforms

    Science.gov (United States)

    Friedman, J. D.; Frank, D. G.; Preble, D.; Painter, J. E.

    1973-01-01

    A combination of infrared images depicting areas of thermal emission and ground calibration points have proved to be particularly useful in plotting time-dependent changes in surface temperatures and radiance and in delimiting areas of predominantly convective heat flow to the earth's surface in the Cascade Range and on Surtsey Volcano, Iceland. In an integrated experiment group using ERTS-1 multispectral scanner (MSS) and aircraft infrared imaging systems in conjunction with multiple thermistor arrays, volcano surface temperatures are relayed daily to Washington via data communication platform (DCP) transmitters and ERTS-1. ERTS-1 MSS imagery has revealed curvilinear structures at Lassen, the full extent of which have not been previously mapped. Interestingly, the major surface thermal manifestations at Lassen are aligned along these structures, particularly in the Warner Valley.

  20. Neutron cross sections for defect production by high-energy displacement cascades in copper

    International Nuclear Information System (INIS)

    Heinisch, H.L.; Mann, F.M.

    1983-08-01

    Defect production cross sections for copper have been devised, based on computer simulations of displacement cascades. One thousand cascades ranging in energy from 200 eV to 200 keV were generated with the MARLOWE computer code. The cascades were subjected to a semi-empirical cascade quenching procedure and to short-term annealing with the ALSOME computer code. Functions were fitted to the numbers of defects produced as a function of primary knock-on atom (PKA) damage energy for the following defect types: 1) the total number of point defects after quenching and after short-term annealing, 2) the numbers of free interstitials and free vacancies after shortterm annealing, and 3) the numbers and sizes of vacancy and interstitial clusters after shortterm annealing. In addition, a function describing the number of distinct damage regions (lobes) per cascade was fitted to results of a graphical analysis of the cascade configurations. The defect production functions have been folded into PKA spectra using the NJOY nuclear data processing code system with ENDF/B-V nuclear data to yield neutron cross sections for defect production in copper. The free vacancy cross section displays much less variation with neutron energy than the cross sections for damage energy or total point defects

  1. Digital Systems Analysis

    Science.gov (United States)

    Martin, Vance S.

    2009-01-01

    There have been many attempts to understand how the Internet affects our modern world. There have also been numerous attempts to understand specific areas of the Internet. This article applies Immanuel Wallerstein's World Systems Analysis to our informationalist society. Understanding this world as divided among individual core, semi-periphery,…

  2. VENTILATION TECHNOLOGY SYSTEMS ANALYSIS

    Science.gov (United States)

    The report gives results of a project to develop a systems analysis of ventilation technology and provide a state-of-the-art assessment of ventilation and indoor air quality (IAQ) research needs. (NOTE: Ventilation technology is defined as the hardware necessary to bring outdoor ...

  3. Hadron cascades produced by electromagnetic cascades

    International Nuclear Information System (INIS)

    Nelson, W.R.; Jenkins, T.M.; Ranft, J.

    1986-12-01

    A method for calculating high energy hadron cascades induced by multi-GeV electron and photon beams is described. Using the EGS4 computer program, high energy photons in the EM shower are allowed to interact hadronically according to the vector meson dominance (VMD) model, facilitated by a Monte Carlo version of the dual multistring fragmentation model which is used in the hadron cascade code FLUKA. The results of this calculation compare very favorably with experimental data on hadron production in photon-proton collisions and on the hadron production by electron beams on targets (i.e., yields in secondary particle beam lines). Electron beam induced hadron star density contours are also presented and are compared with those produced by proton beams. This FLUKA-EGS4 coupling technique could find use in the design of secondary beams, in the determination high energy hadron source terms for shielding purposes, and in the estimation of induced radioactivity in targets, collimators and beam dumps

  4. Supporting Space Systems Design via Systems Dependency Analysis Methodology

    Science.gov (United States)

    Guariniello, Cesare

    The increasing size and complexity of space systems and space missions pose severe challenges to space systems engineers. When complex systems and Systems-of-Systems are involved, the behavior of the whole entity is not only due to that of the individual systems involved but also to the interactions and dependencies between the systems. Dependencies can be varied and complex, and designers usually do not perform analysis of the impact of dependencies at the level of complex systems, or this analysis involves excessive computational cost, or occurs at a later stage of the design process, after designers have already set detailed requirements, following a bottom-up approach. While classical systems engineering attempts to integrate the perspectives involved across the variety of engineering disciplines and the objectives of multiple stakeholders, there is still a need for more effective tools and methods capable to identify, analyze and quantify properties of the complex system as a whole and to model explicitly the effect of some of the features that characterize complex systems. This research describes the development and usage of Systems Operational Dependency Analysis and Systems Developmental Dependency Analysis, two methods based on parametric models of the behavior of complex systems, one in the operational domain and one in the developmental domain. The parameters of the developed models have intuitive meaning, are usable with subjective and quantitative data alike, and give direct insight into the causes of observed, and possibly emergent, behavior. The approach proposed in this dissertation combines models of one-to-one dependencies among systems and between systems and capabilities, to analyze and evaluate the impact of failures or delays on the outcome of the whole complex system. The analysis accounts for cascading effects, partial operational failures, multiple failures or delays, and partial developmental dependencies. The user of these methods can

  5. Actinide isotopic analysis systems

    International Nuclear Information System (INIS)

    Koenig, Z.M.; Ruhter, W.D.; Gunnink, R.

    1990-01-01

    This manual provides instructions and procedures for using the Lawrence Livermore National Laboratory's two-detector actinide isotope analysis system to measure plutonium samples with other possible actinides (including uranium, americium, and neptunium) by gamma-ray spectrometry. The computer program that controls the system and analyzes the gamma-ray spectral data is driven by a menu of one-, two-, or three-letter options chosen by the operator. Provided in this manual are descriptions of these options and their functions, plus detailed instructions (operator dialog) for choosing among the options. Also provided are general instructions for calibrating the actinide isotropic analysis system and for monitoring its performance. The inventory measurement of a sample's total plutonium and other actinides content is determined by two nondestructive measurements. One is a calorimetry measurement of the sample's heat or power output, and the other is a gamma-ray spectrometry measurement of its relative isotopic abundances. The isotopic measurements needed to interpret the observed calorimetric power measurement are the relative abundances of various plutonium and uranium isotopes and americium-241. The actinide analysis system carries out these measurements. 8 figs

  6. Network systems security analysis

    Science.gov (United States)

    Yilmaz, Ä.°smail

    2015-05-01

    Network Systems Security Analysis has utmost importance in today's world. Many companies, like banks which give priority to data management, test their own data security systems with "Penetration Tests" by time to time. In this context, companies must also test their own network/server systems and take precautions, as the data security draws attention. Based on this idea, the study cyber-attacks are researched throughoutly and Penetration Test technics are examined. With these information on, classification is made for the cyber-attacks and later network systems' security is tested systematically. After the testing period, all data is reported and filed for future reference. Consequently, it is found out that human beings are the weakest circle of the chain and simple mistakes may unintentionally cause huge problems. Thus, it is clear that some precautions must be taken to avoid such threats like updating the security software.

  7. MTBF evaluation for 2-out-of-3 redundant repairable systems with common cause and cascade failures considering fuzzy rates for failures and repair: a case study of a centrifugal water pumping system

    Science.gov (United States)

    Mortazavi, Seyed Mohammad; Mohamadi, Maryam; Jouzdani, Javid

    2017-08-01

    In many cases, redundant systems are beset by both independent and dependent failures. Ignoring dependent variables in MTBF evaluation of redundant systems hastens the occurrence of failure, causing it to take place before the expected time, hence decreasing safety and creating irreversible damages. Common cause failure (CCF) and cascading failure are two varieties of dependent failures, both leading to a considerable decrease in the MTBF of redundant systems. In this paper, the alpha-factor model and the capacity flow model are combined so as to incorporate CCF and cascading failure in the evaluation of MTBF of a 2-out-of-3 repairable redundant system. Then, using a transposed matrix, the MTBF function of the system is determined. Due to the fact that it is difficult to estimate the independent and dependent failure rates, industries are interested in considering uncertain failure rates. Therefore, fuzzy theory is used to incorporate uncertainty into the model presented in this study, and a nonlinear programming model is used to determine system's MTBF. Finally, in order to validate the proposed model, evaluation of MTBF of the redundant system of a centrifugal water pumping system is presented as a practical example.

  8. Interband Cascade Photovoltaic Cells

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Rui Q. [Univ. of Oklahoma, Norman, OK (United States); Santos, Michael B. [Univ. of Oklahoma, Norman, OK (United States); Johnson, Matthew B. [Univ. of Oklahoma, Norman, OK (United States)

    2014-09-24

    In this project, we are performing basic and applied research to systematically investigate our newly proposed interband cascade (IC) photovoltaic (PV) cells [1]. These cells follow from the great success of infrared IC lasers [2-3] that pioneered the use of quantum-engineered IC structures. This quantum-engineered approach will enable PV cells to efficiently convert infrared radiation from the sun or other heat source, to electricity. Such cells will have important applications for more efficient use of solar energy, waste-heat recovery, and power beaming in combination with mid-infrared lasers. The objectives of our investigations are to: achieve extensive understanding of the fundamental aspects of the proposed PV structures, develop the necessary knowledge for making such IC PV cells, and demonstrate prototype working PV cells. This research will focus on IC PV structures and their segments for utilizing infrared radiation with wavelengths from 2 to 5 μm, a range well suited for emission by heat sources (1,000-2,000 K) that are widely available from combustion systems. The long-term goal of this project is to push PV technology to longer wavelengths, allowing for relatively low-temperature thermal sources. Our investigations address material quality, electrical and optical properties, and their interplay for the different regions of an IC PV structure. The tasks involve: design, modeling and optimization of IC PV structures, molecular beam epitaxial growth of PV structures and relevant segments, material characterization, prototype device fabrication and testing. At the end of this program, we expect to generate new cutting-edge knowledge in the design and understanding of quantum-engineered semiconductor structures, and demonstrate the concepts for IC PV devices with high conversion efficiencies.

  9. Inverse design technique for cascades

    Science.gov (United States)

    Zannetti, L.; Pandolfi, M.

    1984-01-01

    A numerical technique to generate cascades is presented. The basic prescribed parameters are: inlet angle, exit pressure, and distribution of blade thickness and lift along a blade. Other sets of parameters are also discussed. The technique is based on the lambda scheme. The problem of stability of the computation as a function of the prescribed set of parameters and the treatment of boundary conditions is discussed. A one dimensional analysis to indicate a possible way for assuring stability for any two dimensional calculation is provided.

  10. DART system analysis.

    Energy Technology Data Exchange (ETDEWEB)

    Boggs, Paul T.; Althsuler, Alan (Exagrid Engineering); Larzelere, Alex R. (Exagrid Engineering); Walsh, Edward J.; Clay, Ruuobert L.; Hardwick, Michael F. (Sandia National Laboratories, Livermore, CA)

    2005-08-01

    The Design-through-Analysis Realization Team (DART) is chartered with reducing the time Sandia analysts require to complete the engineering analysis process. The DART system analysis team studied the engineering analysis processes employed by analysts in Centers 9100 and 8700 at Sandia to identify opportunities for reducing overall design-through-analysis process time. The team created and implemented a rigorous analysis methodology based on a generic process flow model parameterized by information obtained from analysts. They also collected data from analysis department managers to quantify the problem type and complexity distribution throughout Sandia's analyst community. They then used this information to develop a community model, which enables a simple characterization of processes that span the analyst community. The results indicate that equal opportunity for reducing analysis process time is available both by reducing the ''once-through'' time required to complete a process step and by reducing the probability of backward iteration. In addition, reducing the rework fraction (i.e., improving the engineering efficiency of subsequent iterations) offers approximately 40% to 80% of the benefit of reducing the ''once-through'' time or iteration probability, depending upon the process step being considered. Further, the results indicate that geometry manipulation and meshing is the largest portion of an analyst's effort, especially for structural problems, and offers significant opportunity for overall time reduction. Iteration loops initiated late in the process are more costly than others because they increase ''inner loop'' iterations. Identifying and correcting problems as early as possible in the process offers significant opportunity for time savings.

  11. Multi-Objective Sustainable Operation of the Three Gorges Cascaded Hydropower System Using Multi-Swarm Comprehensive Learning Particle Swarm Optimization

    Directory of Open Access Journals (Sweden)

    Xiang Yu

    2016-06-01

    Full Text Available Optimal operation of hydropower reservoir systems often needs to optimize multiple conflicting objectives simultaneously. The conflicting objectives result in a Pareto front, which is a set of non-dominated solutions. Non-dominated solutions cannot outperform each other on all the objectives. An optimization framework based on the multi-swarm comprehensive learning particle swarm optimization algorithm is proposed to solve the multi-objective operation of hydropower reservoir systems. Through adopting search techniques such as decomposition, mutation and differential evolution, the algorithm tries to derive multiple non-dominated solutions reasonably distributed over the true Pareto front in one single run, thereby facilitating determining the final tradeoff. The long-term sustainable planning of the Three Gorges cascaded hydropower system consisting of the Three Gorges Dam and Gezhouba Dam located on the Yangtze River in China is studied. Two conflicting objectives, i.e., maximizing hydropower generation and minimizing deviation from the outflow lower target to realize the system’s economic, environmental and social benefits during the drought season, are optimized simultaneously. Experimental results demonstrate that the optimization framework helps to robustly derive multiple feasible non-dominated solutions with satisfactory convergence, diversity and extremity in one single run for the case studied.

  12. Active Stand-off Detection of Gas Leaks Using a Short Range Hard-target Backscatter Differential Optical Absorption System Based on a Quantum Cascade Laser Transmitter

    Directory of Open Access Journals (Sweden)

    Diaz Adrian

    2016-01-01

    Full Text Available Fugitive gas emissions from agricultural or industrial plants and gas pipelines are an important environmental concern as they can contribute to the global increase of greenhouse gas concentration. Moreover, they are also a security and safety concern because of possible risk of fire/explosion or toxicity. This study presents gas concentration measurements using a quantum cascade laser open path system (QCLOPS. The system retrieves the pathaveraged concentration of N2O and CH4 by collecting the backscattered light from a scattering target. The gas concentration measurements have a high temporal resolution (68 ms and are achieved at sufficient range (up to 40 m, ~ 130 feet with a detection limit of 2.6 ppm CH4 and 0.4 ppm for N2O. Given these characteristics, this system is promising for mobile/multidirectional remote detection and evaluation of gas leaks. The instrument is monostatic with a tunable QCL emitting at ~ 7.7 μm wavelength range. The backscattered radiation is collected by a Newtonian telescope and focused on an infrared light detector. Puffs of N2O and CH4 are released along the optical path to simulate a gas leak. The measured absorption spectrum is obtained using the thermal intra-pulse frequency chirped DFB QCL and is analyzed to obtain path averaged gas concentrations.

  13. Stability Analysis of a Helicopter with an External Slung Load System

    Directory of Open Access Journals (Sweden)

    Kary Thanapalan

    2016-01-01

    Full Text Available This paper describes the stability analysis of a helicopter with an underslung external load system. The Lyapunov second method is considered for the stability analysis. The system is considered as a cascade connection of uncertain nonlinear system. The stability analysis is conducted to ensure the stabilisation of the helicopter system and the positioning of the underslung load at hover condition. Stability analysis and numerical results proved that if desired condition for the stability is met, then it is possible to locate the load at the specified position or its neighbourhood.

  14. Cascading ocean basins: numerical simulations of the circulation and interbasin exchange in the Azov-Black-Marmara-Mediterranean Seas system

    Science.gov (United States)

    Stanev, Emil Vassilev; Grashorn, Sebastian; Zhang, Yinglong Joseph

    2017-08-01

    -Black Seas from the other side. The straits of Kerch and Dardanelles provide sufficient interbasin connectivity that prevents large phase lags of the sea levels in the neighboring basins. The two-layer flows in the three straits considered here show different dependencies upon the net transport, and the spatial variability of this dependence is also quite pronounced. We show that the blocking of the surface flow can occur at different net transports, thus casting doubt on a previous approach of using simple relationships to prescribe (steady) outflow and inflow. Specific attention is paid to the role of synoptic atmospheric forcing for the basin-wide circulation and redistribution of mass in the Black Sea. An important controlling process is the propagation of coastal waves. One major conclusion from this research is that modeling the individual basins separately could result in large inaccuracies because of the critical importance of the cascading character of these interconnected basins.

  15. Split energy cascade in turbulent thin fluid layers

    Science.gov (United States)

    Musacchio, Stefano; Boffetta, Guido

    2017-11-01

    We discuss the phenomenology of the split energy cascade in a three-dimensional thin fluid layer by means of high resolution numerical simulations of the Navier-Stokes equations. We observe the presence of both an inverse energy cascade at large scales, as predicted for two-dimensional turbulence, and a direct energy cascade at small scales, as in three-dimensional turbulence. The inverse energy cascade is associated with a direct cascade of enstrophy in the intermediate range of scales. Notably, we find that the inverse cascade of energy in this system is not a purely 2D phenomenon, as the coupling with the 3D velocity field is necessary to guarantee the constancy of fluxes.

  16. Analysis of the multiple roles of gld-1 in germline development: Interactions with the sex determination cascade and the glp-1 signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Francis, R.; Schedl, T. [Washington Univ. School of Medicine, St. Louis, MO (United States); Maine, E. [Syracuse Univ., NY (United States)

    1995-02-01

    The Caenorhabditis elegans gene gld-1 is essential for oocyte development; in gld-1 (null) hermaphrodites, a tumor forms where oogenesis would normally occur. We use genetic epistasis analysis to demonstrate that tumor formation is dependent on the sexual fate of the germline. When the germline sex determination pathway is set in the female mode (terminal fem/fog genes inactive), gld-1 (null) germ cells exit meiotic prophase and proliferate to form a tumor, but when the pathway is et in the male mode, they develop into sperm. We conclude that the gld-1 (null) phenotype is cell-type specific and that gld-1(+) acts at the end of the cascade to direct oogenesis. We also use cell ablation and epistasis analysis to examine the dependence of tumor formation on the glp-1 signaling pathway. Although glp-1 activity promotes tumor growth, it is not essential for tumor formation by gld-1 (null) germ cells. These data also reveal that gld-1(+) plays a nonessential (and sex nonspecific) role in regulating germ cell proliferation before their entry into meiosis. Thus gld-1(+) may negatively regulate proliferation at two distinct points in germ cell development: before entry into meiotic prophase in both sexes (nonessential premeiotic gld-1 function) and during meiotic prophase when the sex determination pathway is set in the female mode (essential meiotic gld-1 function). 46 refs., 9 figs., 4 tabs.

  17. Intranuclear cascade+percolation+evaporation model applied to the {sup 12}C+{sup 197}Au system at 1 GeV/nucleon

    Energy Technology Data Exchange (ETDEWEB)

    Volant, C.; Turzo, K.; Trautmann, W.; Auger, G.; Begemann-Blaich, M.-L.; Bittiger, R.; Borderie, B.; Botvina, A.S.; Bougault, R.; Bouriquet, B.; Charvet, J.-L.; Chbihi, A.; Dayras, R.; Dore, D.; Durand, D.; Frankland, J.D.; Galichet, E.; Gourio, D.; Guinet, D.; Hudan, S.; Imme, G.; Lautesse, Ph.; Lavaud, F.; Le Fevre, A.; Lopez, O.; Lukasik, J.; Lynen, U.; Mueller, W.F.J.; Nalpas, L.; Orth, H.; Plagnol, E.; Raciti, G.; Rosato, E.; Saija, A.; Schwarz, C.; Seidel, W.; Sfienti, C.; Steckmeyer, J.C.; Tamain, B.; Trzcinski, A.; Vient, E.; Vigilante, M.; Zwieglinski, B

    2004-04-05

    The nucleus-nucleus Liege intranuclear-cascade+percolation+evaporation model has been applied to the {sup 12}C+{sup 197}Au data measured by the INDRA-ALADIN collaboration at GSI. After the intranuclear cascade stage, the data are better reproduced when using the Statistical Multiframentation Model as afterburner. Further checks of the model are done on data from the EOS and KAOS collaborations.

  18. Atomic-Scale Simulations of Cascade Overlap and Damage Evolution in Silicon Carbide

    International Nuclear Information System (INIS)

    Gao, Fei; Weber, William J.

    2003-01-01

    In a previous computer simulation experiment, the accumulation of damage in SiC from the overlap of 10 keV Si displacement cascades at 200 K was investigated, and the damage states produced following each cascade were archived for further analysis. In the present study, interstitial clustering, system energy, and volume changes are investigated as the damage states evolve due to cascade overlap. An amorphous state is achieved at a damage energy density of 27.5 eV/atom (0.28 displacements per atom). At low dose levels, most defects are produced as isolated Frenkel pairs, with a small number of defect clusters involving only 4 to 6 atoms; however, after the overlap of 5 cascades (0.0125 displacements per atom), the size and number of interstitial clusters increases with increasing dose. The average energy per atom increases linearly with increasing short-range (or chemical) disorder. The volume change exhibits two regimes of linear dependence on system energy and increases more rapidly with dose than either the energy or the disorder, which indicate a significant contribution to swelling of isolated interstitials and anti-site defects. The saturation volume change for the cascade-amorphized state in these simulations is 8.2%, which is in reasonable agreement with the experimental value of 10.8% in neutron-irradiated SiC

  19. Gas separation performance of tapered cascade with membrane

    International Nuclear Information System (INIS)

    Ohno, Masayoshi; Morisue, Tetsuo; Ozaki, Osamu; Miyauchi, Terukatsu.

    1978-01-01

    Membrane gas separation cascades are analyzed at steady state. The method of calculating the flow rate and concentration profiles in the cascade are examined, using formulas expressing the various membrane separation cell characteristics. The method adopted is applicable to relatively high concentrations and separation factors. Considerations are further given on the steady state performance of four theoretical forms of cascade: (a) with common value of cut for all stages, (b) with symmetric separation cells, (c) with no mixing at the junction at each stage, and (d) ideal cascade. The analysis showed that, with membrane cells, the ideal cascade would have a pressure ratio varying from stage to stage. The symmetric separation cascade would provide a separation performance lower than the ideal cascade on account of the mixing at the junctions of streams possessing different concentrations, whereas the cut and separation factor of the no-mixing cascade requiring minimum membrane area exhibits zig-zag curves when plotted against stage number. Both these circumstances contribute to the lower separation performance obtained with these two forms as compared with the ideal cascade, and results in larger total membrane area; but these semi-ideal forms retain the advantage of easy practical treatment with their pressure ratio common to all stages. (auth.)

  20. 36 CFR 7.66 - North Cascades National Park.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false North Cascades National Park. 7.66 Section 7.66 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.66 North Cascades National Park. (a...

  1. Logical analysis of biological systems

    DEFF Research Database (Denmark)

    Mardare, Radu Iulian

    2005-01-01

    R. Mardare, Logical analysis of biological systems. Fundamenta Informaticae, N 64:271-285, 2005.......R. Mardare, Logical analysis of biological systems. Fundamenta Informaticae, N 64:271-285, 2005....

  2. Proposal and Evaluation of a Gas Engine and Gas Turbine Hybrid Cogeneration System in which Cascaded Heat is Highly Utilized

    Science.gov (United States)

    Pak, Pyong Sik

    A high efficiency cogeneration system (CGS) is proposed for utilizing high temperature exhaust gas (HTEG) from a gas engine (GE). In the proposed system, for making use of heat energy of HTEG, H2O turbine (HTb) is incorporated and steam produced by utilizing HTEG is used as working fluid of HTb. HTb exhaust gas is also utilized for increasing power output and for satisfying heat demand in the proposed system. Both of the thermodynamic characteristics of the proposed system and a gas engine CGS (GE-CGS) constructed by using the original GE are estimated. Energy saving characteristics and CO2 reduction effects of the proposed CGS and the GE-CGS are also investigated. It was estimated that the net generated power of the proposed CGS has been increasd 25.5% and net power generation efficiency 6.7%, compared with the the original GE-CGS. It was also shown that the proposed CGS could save 27.0% of energy comsumption and reduce 1137 t-CO2/y, 1.41 times larger than those of GE-CGS, when a case syudy was set and investigated. Improvements of performance by increasing turbine inlet temperature were also investigated.

  3. Design concept of a cryogenic distillation column cascade for a ITER scale fusion reactor

    International Nuclear Information System (INIS)

    Yamanishi, Toshihiko; Enoeda, Mikio; Okuno, Kenji

    1994-07-01

    A column cascade has been proposed for the fuel cycle of a ITER scale fusion reactor. The proposed cascade consists of three columns and has significant features: either top or bottom product is prior to the other for each column: it is avoided to withdraw side streams as products or feeds of down stream columns: and there is no recycle steam between the columns. In addition, the product purity of the cascade can be maintained against the changes of flow rates and compositions of feed streams just by adjusting the top and bottom flow rates. The control system has been designed for each column in the cascade. A key component in the prior product stream was selected, and the analysis method of this key component was proposed. The designed control system never brings instability as long as the concentration of the key component is measured with negligible time lag. The time lag for the measurement considerably affects the stability of the control system. A significant conclusion by the simulation in this work is that permissible time for the measurement is about 0.5 hour to obtain stable control. Hence, the analysis system using the gas chromatography is valid for control of the columns. (author)

  4. Is current disruption associated with an inverse cascade?

    Directory of Open Access Journals (Sweden)

    Z. Vörös

    2010-06-01

    Full Text Available Current disruption (CD and the related kinetic instabilities in the near-Earth magnetosphere represent physical mechanisms which can trigger multi-scale substorm activity including global reorganizations of the magnetosphere. Lui et al. (2008 proposed a CD scenario in which the kinetic scale linear modes grow and reach the typical dipolarization scales through an inverse cascade. The experimental verification of the inverse nonlinear cascade is based on wavelet analysis. In this paper the Hilbert-Huang transform is used which is suitable for nonlinear systems and allows to reconstruct the time-frequency representation of empirical decomposed modes in an adaptive manner. It was found that, in the Lui et al. (2008 event, the modes evolve globally from high-frequencies to low-frequencies. However, there are also local frequency evolution trends oriented towards high-frequencies, indicating that the underlying processes involve multi-scale physics and non-stationary fluctuations for which the simple inverse cascade scenario is not correct.

  5. Efficient collective influence maximization in cascading processes with first-order transitions

    Science.gov (United States)

    Pei, Sen; Teng, Xian; Shaman, Jeffrey; Morone, Flaviano; Makse, Hernán A.

    2017-01-01

    In many social and biological networks, the collective dynamics of the entire system can be shaped by a small set of influential units through a global cascading process, manifested by an abrupt first-order transition in dynamical behaviors. Despite its importance in applications, efficient identification of multiple influential spreaders in cascading processes still remains a challenging task for large-scale networks. Here we address this issue by exploring the collective influence in general threshold models of cascading process. Our analysis reveals that the importance of spreaders is fixed by the subcritical paths along which cascades propagate: the number of subcritical paths attached to each spreader determines its contribution to global cascades. The concept of subcritical path allows us to introduce a scalable algorithm for massively large-scale networks. Results in both synthetic random graphs and real networks show that the proposed method can achieve larger collective influence given the same number of seeds compared with other scalable heuristic approaches. PMID:28349988

  6. Topology and Control of Transformerless High Voltage Grid-connected PV System Based on Cascade Step-up Structure

    DEFF Research Database (Denmark)

    Yang, Zilong; Wang, Zhe; Zhang, Ying

    2017-01-01

    quality regulation. Its inherent excellent features makes it not only adapt to different geographical and environmental installing conditions, but also to improve converter efficiency and flexibility. This paper focuses on the analyses of system structure design, control principle and strategy......, and then comparing the performance of different PV plant structures, including central, multi-string and this novel series-connected structure. Additionally,, by properly choosing storage battery capacity in accordance with the demand of power grid and load, this structure is able to achieve short-term power grid...

  7. Advanced exergoeconomic analysis of the multistage mixed refrigerant systems

    International Nuclear Information System (INIS)

    Mehrpooya, Mehdi; Ansarinasab, Hojat

    2015-01-01

    Highlights: • Advanced exergoeconomic analysis is performed for mixed refrigerant systems. • Cost of investment is divided into avoidable/unavoidable and endogenous/exogenous. • Results show that interactions between the components is not considerable. - Abstract: Advanced exergoeconomic analysis is applied on three multi stage mixed refrigerant liquefaction processes. They are propane precooled mixed refrigerant, dual mixed refrigerant and mixed fluid cascade. Cost of investment and exergy destruction for the components with high inefficiencies are divided into avoidable/unavoidable and endogenous/exogenous parts. According to the avoidable exergy destruction cost in propane precooled mixed refrigerant process, C-2 compressor with 455.5 ($/h), in dual mixed refrigerant process, C-1 compressor with 510.8 ($/h) and in mixed fluid cascade process, C-2/1 compressor with 338.8 ($/h) should be considered first. A comparison between the conventional and advanced exergoeconomic analysis is done by three important parameters: Exergy efficiency, exergoeconomic factor and total costs. Results show that interactions between the process components are not considerable because cost of investment and exergy destruction in most of them are endogenous. Exergy destruction cost of the compressors is avoidable while heat exchangers and air coolers destruction cost are unavoidable. Investment cost of heat exchangers and air coolers are avoidable while compressor’s are unavoidable

  8. One-Pot Synthesis of Hyperoside by a Three-Enzyme Cascade Using a UDP-Galactose Regeneration System.

    Science.gov (United States)

    Pei, Jianjun; Chen, Anna; Zhao, Linguo; Cao, Fuliang; Ding, Gang; Xiao, Wei

    2017-07-26

    Hyperoside exhibits many biological properties and is more soluble in water than quercetin. A uridine 5'-diphosphate (UDP) galactose regeneration system and one-pot synthesis of hyperoside was described herein. Glycine max sucrose synthase (GmSUS) was coupled with Escherichia coli UDP-galactose 4-epimerase (GalE) to regenerate UDP-galactose from sucrose and UDP. Petunia hybrida glycosyltransferase (PhUGT) with high activity toward quercetin was used to synthesize hyperoside via the UDP-galactose regeneration system. The important factors for optimal synergistic catalysis were determined. Through the use of a fed-batch operation, the final titer of hyperoside increased to 2134 mg/L, with a corresponding molar conversion of 92% and maximum number of UDP-galactose regeneration cycles (RC max ) of 18.4 under optimal conditions. Therefore, the method described herein for the regeneration of UDP-galactose from UDP and sucrose can be widely used for the glycosylation of flavonoids and other bioactive substances.

  9. Antithyroid drug detection using an enzyme cascade blocking in a nanoparticle-based lab-on-a-chip system.

    Science.gov (United States)

    Kurbanoglu, Sevinc; Mayorga-Martinez, Carmen C; Medina-Sánchez, Mariana; Rivas, Lourdes; Ozkan, Sibel A; Merkoçi, Arben

    2015-05-15

    A methimazole (MT) biosensor based on a nanocomposite of magnetic nanoparticles (MNPs) functionalized with iridium oxide nanoparticles (IrOx NPs) and tyrosinase (Tyr) immobilized onto screen printed electrode (SPE) by using a permanent magnet is presented. This system is evaluated in batch mode via chelating copper at the active site of tyrosinase and in flow mode by thioquinone formation. The MT detection in flow mode is achieved using a hybrid polydimethylsiloxane/polyester amperometric lab-on-a-chip (LOC) microsystem with an integrated SPE. Both systems are very sensitive with low limit of detection (LOD): 0.006 μM and 0.004 μM for batch and flow modes, respectively. Nevertheless, the flow mode has advantages such as its reusability, automation, low sample volume (6 μL), and fast response (20 s). Optimization and validation parameters such as enzyme-substrate amount, flow rate, inhibition conditions, repeatability and reproducibility of the biosensor have been performed. The proposed methods have been applied in MT detection in spiked human serum and pharmaceutical dosage forms. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Computational systems analysis of dopamine metabolism.

    Directory of Open Access Journals (Sweden)

    Zhen Qi

    2008-06-01

    Full Text Available A prominent feature of Parkinson's disease (PD is the loss of dopamine in the striatum, and many therapeutic interventions for the disease are aimed at restoring dopamine signaling. Dopamine signaling includes the synthesis, storage, release, and recycling of dopamine in the presynaptic terminal and activation of pre- and post-synaptic receptors and various downstream signaling cascades. As an aid that might facilitate our understanding of dopamine dynamics in the pathogenesis and treatment in PD, we have begun to merge currently available information and expert knowledge regarding presynaptic dopamine homeostasis into a computational model, following the guidelines of biochemical systems theory. After subjecting our model to mathematical diagnosis and analysis, we made direct comparisons between model predictions and experimental observations and found that the model exhibited a high degree of predictive capacity with respect to genetic and pharmacological changes in gene expression or function. Our results suggest potential approaches to restoring the dopamine imbalance and the associated generation of oxidative stress. While the proposed model of dopamine metabolism is preliminary, future extensions and refinements may eventually serve as an in silico platform for prescreening potential therapeutics, identifying immediate side effects, screening for biomarkers, and assessing the impact of risk factors of the disease.

  11. Comparative analysis of the luminescence microscopy and cascade filtration methods for estimating bacterial abundance and biomass in the soil: Role of soil suspension dilution

    Science.gov (United States)

    Polyanskaya, L. M.; Pinchuk, I. P.; Stepanov, A. L.

    2017-10-01

    Bacterial abundance and biomass in cultivated soddy-podzolic soil have been studied by luminescence microscopy and cascade filtration. It is found that bacterial biomass determined by cascade filtration is higher than that counted by the direct method of luminescence on slides by one order of magnitude. This result is because the cascade filtration method for the estimation of bacterial biomass is capable to more accurately calculate bacterial abundance with consideration for bacteria from different size groups. This results in a larger bacterial biomass in soils. It should be noted that bacterial abundance calculated for the initial dilution (1: 100 to 1: 10000) decreases in 3, 10, and 20 times rather than in the expected 10, 100, and 1000 times, respectively. The obtained results are of great importance for the correction of concepts about fungal and bacterial biomass ratios in different soil types.

  12. Proteomics analysis of global regulatory cascades involved in clavulanic acid production and morphological development in Streptomyces clavuligerus.

    Science.gov (United States)

    Ferguson, Nicole L; Peña-Castillo, Lourdes; Moore, Marcus A; Bignell, Dawn R D; Tahlan, Kapil

    2016-04-01

    The genus Streptomyces comprises bacteria that undergo a complex developmental life cycle and produce many metabolites of importance to industry and medicine. Streptomyces clavuligerus produces the β-lactamase inhibitor clavulanic acid, which is used in combination with β-lactam antibiotics to treat certain β-lactam resistant bacterial infections. Many aspects of how clavulanic acid production is globally regulated in S. clavuligerus still remains unknown. We conducted comparative proteomics analysis using the wild type strain of S. clavuligerus and two mutants (ΔbldA and ΔbldG), which are defective in global regulators and vary in their ability to produce clavulanic acid. Approximately 33.5 % of the predicted S. clavuligerus proteome was detected and 192 known or putative regulatory proteins showed statistically differential expression levels in pairwise comparisons. Interestingly, the expression of many proteins whose corresponding genes contain TTA codons (predicted to require the bldA tRNA for translation) was unaffected in the bldA mutant.

  13. Efficient Production of Enantiopure d-Lysine from l-Lysine by a Two-Enzyme Cascade System

    Directory of Open Access Journals (Sweden)

    Xin Wang

    2016-10-01

    Full Text Available The microbial production of d-lysine has been of great interest as a medicinal raw material. Here, a two-step process for d-lysine production from l-lysine by the successive microbial racemization and asymmetric degradation with lysine racemase and decarboxylase was developed. The whole-cell activities of engineered Escherichia coli expressing racemases from the strains Proteus mirabilis (LYR and Lactobacillus paracasei (AAR were first investigated comparatively. When the strain BL21-LYR with higher racemization activity was employed, l-lysine was rapidly racemized to give dl-lysine, and the d-lysine yield was approximately 48% after 0.5 h. Next, l-lysine was selectively catabolized to generate cadaverine by lysine decarboxylase. The comparative analysis of the decarboxylation activities of resting whole cells, permeabilized cells, and crude enzyme revealed that the crude enzyme was the best biocatalyst for enantiopure d-lysine production. The reaction temperature, pH, metal ion additive, and pyridoxal 5′-phosphate content of this two-step production process were subsequently optimized. Under optimal conditions, 750.7 mmol/L d-lysine was finally obtained from 1710 mmol/L l-lysine after 1 h of racemization reaction and 0.5 h of decarboxylation reaction. d-lysine yield could reach 48.8% with enantiomeric excess (ee ≥ 99%.

  14. Piscivores, Trophic Cascades, and Lake Management

    Directory of Open Access Journals (Sweden)

    Ray W. Drenner

    2002-01-01

    Full Text Available The concept of cascading trophic interactions predicts that an increase in piscivore biomass in lakes will result in decreased planktivorous fish biomass, increased herbivorous zooplankton biomass, and decreased phytoplankton biomass. Though often accepted as a paradigm in the ecological literature and adopted by lake managers as a basis for lake management strategies, the trophic cascading interactions hypothesis has not received the unequivocal support (in the form of rigorous experimental testing that might be expected of a paradigm. Here we review field experiments and surveys, testing the hypothesis that effects of increasing piscivore biomass will cascade down through the food web yielding a decline in phytoplankton biomass. We found 39 studies in the scientific literature examining piscivore effects on phytoplankton biomass. Of the studies, 22 were confounded by supplemental manipulations (e.g., simultaneous reduction of nutrients or removal of planktivores and could not be used to assess piscivore effects. Of the 17 nonconfounded studies, most did not find piscivore effects on phytoplankton biomass and therefore did not support the trophic cascading interactions hypothesis. However, the trophic cascading interactions hypothesis also predicts that lake systems containing piscivores will have lower phytoplankton biomass for any given phosphorus concentration. Based on regression analyses of chlorophyll�total phosphorus relationships in the 17 nonconfounded piscivore studies, this aspect of the trophic cascading interactions hypothesis was supported. The slope of the chlorophyll vs. total phosphorus regression was lower in lakes with planktivores and piscivores compared with lakes containing only planktivores but no piscivores. We hypothesize that this slope can be used as an indicator of “functional piscivory” and that communities with extremes of functional piscivory (zero and very high represent classical 3- and 4-trophic level

  15. High-spatial-resolution localization algorithm based on cascade deconvolution in a distributed Sagnac interferometer invasion monitoring system.

    Science.gov (United States)

    Pi, Shaohua; Wang, Bingjie; Zhao, Jiang; Sun, Qi

    2016-10-10

    In the Sagnac fiber optic interferometer system, the phase difference signal can be illustrated as a convolution of the waveform of the invasion with its occurring-position-associated transfer function h(t); deconvolution is introduced to improve the spatial resolution of the localization. In general, to get a 26 m spatial resolution at a sampling rate of 4×106  s-1, the algorithm should mainly go through three steps after the preprocessing operations. First, the decimated phase difference signal is transformed from the time domain into the real cepstrum domain, where a probable region of invasion distance can be ascertained. Second, a narrower region of invasion distance is acquired by coarsely assuming and sweeping a transfer function h(t) within the probable region and examining where the restored invasion waveform x(t) gets its minimum standard deviation. Third, fine sweeping the narrow region point by point with the same criteria is used to get the final localization. Also, the original waveform of invasion can be restored for the first time as a by-product, which provides more accurate and pure characteristics for further processing, such as subsequent pattern recognition.

  16. Systems analysis of a security alarm system

    International Nuclear Information System (INIS)

    Schiff, A.

    1975-01-01

    When the Lawrence Livermore Laboratory found that its security alarm system was causing more false alarms and maintenance costs than LLL felt was tolerable, a systems analysis was undertaken to determine what should be done about the situation. This report contains an analysis of security alarm systems in general and ends with a review of the existing Security Alarm Control Console (SACC) and recommendations for its improvement, growth and change. (U.S.)

  17. Assessment of 50%-Propagation-Delay for Cascaded PCB Non-Linear Interconnect Lines for the High-Rate Signal Integrity Analysis

    Directory of Open Access Journals (Sweden)

    T. Eudes

    2013-02-01

    Full Text Available This paper presents an enlarged study about the 50-% propagation-time assessment of cascaded transmission lines (TLs. First and foremost, the accurate modeling and measurement technique of signal integrity (SI for high-rate microelectronic interconnection is recalled. This model is based on the reduced transfer function extracted from the electromagnetic (EM behavior of the interconnect line RLCG-parameters. So, the transfer function established takes into account both the frequency dispersion effects and the different propagation modes. In addition, the transfer function includes also the load and source impedance effects. Then, the SI analysis is proposed for high-speed digital signals through the developed model. To validate the model understudy, a prototype of microstrip interconnection with w = 500 µm and length d = 33 mm was designed, simulated, fabricated and tested. Then, comparisons between the frequency and time domain results from the model and from measurements are performed. As expected, good agreement between the S-parameters form measurements and the model proposed is obtained from DC to 8 GHz. Furthermore, a de-embedding method enabling to cancel out the connectors and the probe effects are also presented. In addition, an innovative time-domain characterization is proposed in order to validate the concept with a 2.38 Gbit/s-input data signal. Afterwards, the 50-% propagation-time assessment problem is clearly exposed. Consequently an extracting theory of this propagation-time with first order RC-circuits is presented. Finally, to show the relevance of this calculation, propagation-time simulations and an application to signal integrity issues are offered.

  18. A virtual component method in numerical computation of cascades for isotope separation

    International Nuclear Information System (INIS)

    Zeng Shi; Cheng Lu

    2014-01-01

    The analysis, optimization, design and operation of cascades for isotope separation involve computations of cascades. In analytical analysis of cascades, using virtual components is a very useful analysis method. For complicated cases of cascades, numerical analysis has to be employed. However, bound up to the conventional idea that the concentration of a virtual component should be vanishingly small, virtual component is not yet applied to numerical computations. Here a method of introducing the method of using virtual components to numerical computations is elucidated, and its application to a few types of cascades is explained and tested by means of numerical experiments. The results show that the concentration of a virtual component is not restrained at all by the 'vanishingly small' idea. For the same requirements on cascades, the cascades obtained do not depend on the concentrations of virtual components. (authors)

  19. A durability analysis of the Cascad facility based on feedback obtained after 10 years of operation; Analyse de la durabilite de l'installation cascad a partir du retour d'experience de 10 ans d'exploitation

    Energy Technology Data Exchange (ETDEWEB)

    Samoel, R.; Canas, D.; Henry, H.; Battesti, P. [CEA Cadarache, Dept. d' Etudes des Combustibles (DEC/SCEC), 13 - Saint-Paul-lez-Durance (France)

    1999-07-01

    The CASCAD facility at the nuclear research centre in Cadarache is a dry storage facility for spent fuel that has been placed in a vault. Feedback on its design and performance after 10 years of operation was obtained in order to identify the factors limiting its life time. This assessment corresponds to a durability analysis based on a combination of dependability methods. This is a critical analysis identifying the risks involving failure of the components when they are subjected to internal and external disturbances (aging, technology obsolescence, etc.). The measures to be implemented to extend the life time of the facility are subsequently enumerated. A proposed synthesis or 'logic diagram' of the analysis is also presented. (authors)

  20. Systems analysis made simple computerbooks

    CERN Document Server

    Antill, Lyn

    1980-01-01

    Systems Analysis: Made Simple Computerbooks introduces the essential elements of information systems analysis and design and teaches basic technical skills required for the tasks involved. The book covers the aspects to the design of an information system; information systems and the organization, including the types of information processing activity and computer-based information systems; the role of the systems analyst; and the human activity system. The text also discusses information modeling, socio-technical design, man-machine interface, and the database design. Software specification

  1. On-stream analysis systems

    International Nuclear Information System (INIS)

    Howarth, W.J.; Watt, J.S.

    1982-01-01

    An outline of some commercially available on-stream analysis systems in given. Systems based on x-ray tube/crystal spectrometers, scintillation detectors, proportional detectors and solid-state detectors are discussed

  2. SCADA system analysis

    International Nuclear Information System (INIS)

    Tuneski, Atanasko; Zaev, Emil

    2000-01-01

    This paper reviews one SCADA (Supervisory Control And Data Acquisition) system and its components. The SCADA system is used to monitor and to control a plant or an equipment. Basically the SCADA system is composed of the following: Field Instrumentation, Remote Stations, Communications Stations, Central Monitoring Station. This paper gives the answer where to use the SCADA, description of all its components and functionality. Since the SCADA is usually used for automatic control of a plant or an equipment, a system which is controlled becomes more productive and easy to work with. (Author)

  3. Geothermal research, Oregon Cascades: Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Priest, G.R.; Black, G.L.

    1988-10-27

    Previous USDOE-funded geothermal studies have produced an extensive temperature gradient and heat flow data base for the State of Oregon. One of the important features identified as a result of these studies is a rapid transition from heat flow values on the order of 40 mW/m/sup 2/ in the Willamette Valley and Western Cascades to values of greater than or equal to100 mW/m/sup 2/ in the High Cascades and the eastern portion of the Western Cascades. These data indicate that the Cascade Range in Oregon has potential as a major geothermal province and stimulated much of the later work completed by government agencies and private industry. Additional data generated as a result of this grant and published in DOGAMI Open-File Report 0-86-2 further define the location and magnitude of this transition zone. In addition, abundant data collected from the vicinity of Breitenbush and Austin Hot Springs have permitted the formulation of relatively detailed models of these hydrothermal systems. These models are published in DOGAMI Open-File Report 0-88-5. Task 1.2 of the Deliverables section of Amendment M001 is fulfilled by DOGAMI publication GMS-48, Geologic map of the McKenzie Bridge quadrangle, Lane County, Oregon. This map was printed in October, 1988, and is part of the final submission to USDOE. 8 refs.

  4. Interband cascade lasers

    International Nuclear Information System (INIS)

    Vurgaftman, I; Meyer, J R; Canedy, C L; Kim, C S; Bewley, W W; Merritt, C D; Abell, J; Weih, R; Kamp, M; Kim, M; Höfling, S

    2015-01-01

    We review the current status of interband cascade lasers (ICLs) emitting in the midwave infrared (IR). The ICL may be considered the hybrid of a conventional diode laser that generates photons via electron–hole recombination, and an intersubband-based quantum cascade laser (QCL) that stacks multiple stages for enhanced current efficiency. Following a brief historical overview, we discuss theoretical aspects of the active region and core designs, growth by molecular beam epitaxy, and the processing of broad-area, narrow-ridge, and distributed feedback (DFB) devices. We then review the experimental performance of pulsed broad area ICLs, as well as the continuous-wave (cw) characteristics of narrow ridges having good beam quality and DFBs producing output in a single spectral mode. Because the threshold drive powers are far lower than those of QCLs throughout the λ = 3–6 µm spectral band, ICLs are increasingly viewed as the laser of choice for mid-IR laser spectroscopy applications that do not require high output power but need to be hand-portable and/or battery operated. Demonstrated ICL performance characteristics to date include threshold current densities as low as 106 A cm −2 at room temperature (RT), cw threshold drive powers as low as 29 mW at RT, maximum cw operating temperatures as high as 118 °C, maximum cw output powers exceeding 400 mW at RT, maximum cw wallplug efficiencies as high as 18% at RT, maximum cw single-mode output powers as high as 55 mW at RT, and single-mode output at λ = 5.2 µm with a cw drive power of only 138 mW at RT. (topical review)

  5. Interband cascade lasers

    Science.gov (United States)

    Vurgaftman, I.; Weih, R.; Kamp, M.; Meyer, J. R.; Canedy, C. L.; Kim, C. S.; Kim, M.; Bewley, W. W.; Merritt, C. D.; Abell, J.; Höfling, S.

    2015-04-01

    We review the current status of interband cascade lasers (ICLs) emitting in the midwave infrared (IR). The ICL may be considered the hybrid of a conventional diode laser that generates photons via electron-hole recombination, and an intersubband-based quantum cascade laser (QCL) that stacks multiple stages for enhanced current efficiency. Following a brief historical overview, we discuss theoretical aspects of the active region and core designs, growth by molecular beam epitaxy, and the processing of broad-area, narrow-ridge, and distributed feedback (DFB) devices. We then review the experimental performance of pulsed broad area ICLs, as well as the continuous-wave (cw) characteristics of narrow ridges having good beam quality and DFBs producing output in a single spectral mode. Because the threshold drive powers are far lower than those of QCLs throughout the λ = 3-6 µm spectral band, ICLs are increasingly viewed as the laser of choice for mid-IR laser spectroscopy applications that do not require high output power but need to be hand-portable and/or battery operated. Demonstrated ICL performance characteristics to date include threshold current densities as low as 106 A cm-2 at room temperature (RT), cw threshold drive powers as low as 29 mW at RT, maximum cw operating temperatures as high as 118 °C, maximum cw output powers exceeding 400 mW at RT, maximum cw wallplug efficiencies as high as 18% at RT, maximum cw single-mode output powers as high as 55 mW at RT, and single-mode output at λ = 5.2 µm with a cw drive power of only 138 mW at RT.

  6. Systems Engineering Analysis

    Directory of Open Access Journals (Sweden)

    Alexei Serna M.

    2013-07-01

    Full Text Available The challenges proposed by the development of the new computer systems demand new guidance related to engineer´s education, because they will solve these problems. In the XXI century, system engineers must be able to integrate a number of topics and knowledge disciplines that complement that traditionally has been known as Computer Systems Engineering. We have enough software development engineers, today we need professional engineers for software integration, leaders and system architects that make the most of the technological development for the benefit of society, leaders that integrate sciences to the solutions they build and propose. In this article the current situation of Computer Systems Engineering is analyzed and is presented a theory proposing the need for modifying the approach Universities have given to these careers, to achieve the education of leader engineers according to the needs of this century.

  7. Terahertz Quantum Cascade Laser Based 3D Imaging Project

    Data.gov (United States)

    National Aeronautics and Space Administration — LongWave Photonics proposes a terahertz quantum-cascade laser based swept-source optical coherence tomography (THz SS-OCT) system for single-sided, 3D,...

  8. Dynamic behavior and control of product enrichment in a centrifuge cascade

    International Nuclear Information System (INIS)

    Okamoto, Tsuyoshi; Suzuki, Atsuyuki; Nishimura, Hideo.

    1989-05-01

    It was agreed as a conclusion of the HEXAPARTITE project that a limited frequency unannounced access (LFUA) inspection should be carried out in a centrifuge type enrichment plant as a basic safeguards approach. It might be adopted at a large scale, future commercial enrichment plant, too. Application of the LFUA approach to such a plant, however, should be fully investigated because the plant will have not only a larger capability of enriching uranium 235 but also a more sensitive information to be protected from the commercial and non-proliferation viewpoint. As a part of a design study on the safeguards approach for a model commercial plant, a study of process simulation of the plant has been carried out. This report describes a result of the study. When a commercial uranium enrichment plant is constructed, a nuisance problem arises; What kind of products should be produced from the plant in order to match a wide range of nuclear fuel enrichment requirements for light-water power reactors. In this report, a reasonable solution to such a problem is investigated. At first, a transient analysis of start-up for a model centrifuge cascade is made by using the dynamic equations, which were so developed as to be able to accurately compute interstage flow rates and enrichment in a transient state. Then it is investigated how wide in its acceptable range the product enrichment can be controlled by regulating cascade characteristic parameters such as cascade cut, recycle flow rate and cascade feed flow rate, and as a result an information about the optimal regulating mode is brought out. As a result of this study, it has become clear that the specific requirements of a customer are almost fulfilled with only one type of unit cascade system if 10 % loss of cascade efficiency is allowed in the plant operation. (author)

  9. Chemical laser systems analysis

    Energy Technology Data Exchange (ETDEWEB)

    Doughty, J.R.

    1988-11-01

    This paper presents a means by which the chemical laser device weight can be minimized with respect to its performance and the device power minimized with respect to the target range. Chemical laser performance parameters such as the specific power and nozzle power flux are then used in conjunction with weight and propagation models to determine system effectiveness. A measure of merit is given by which systems can be contrasted. An illustrative example is included in which DF and Iodine laser systems are compared for an airborne scenario. 14 references.

  10. Energy Usage Analysis System

    Data.gov (United States)

    General Services Administration — The EUAS application is a web based system which serves Energy Center of Expertise, under the Office of Facilitates Management and Service Programs. EUAS is used for...

  11. Care Cascade for targeted tuberculosis testing and linkage to Care in Homeless Populations in the United States: a meta-analysis.

    Science.gov (United States)

    Parriott, Andrea; Malekinejad, Mohsen; Miller, Amanda P; Marks, Suzanne M; Horvath, Hacsi; Kahn, James G

    2018-04-12

    Homelessness increases the risk of tuberculosis (TB) disease and latent TB infection (LTBI), but persons experiencing homelessness often lack access to testing and treatment. We assessed the yield of TB testing and linkage to care for programs targeting homeless populations in the United States. We conducted a comprehensive search of peer-reviewed and grey literature, adapting Cochrane systematic review methods. Two reviewers independently assessed study eligibility and abstracted key data on the testing to care cascade: number of persons reached, recruited for testing, tested for LTBI, with valid test results, referred to follow-up care, and initiating care. We used random effects to calculate pooled proportions and 95% confidence intervals (CI) of persons retained in each step via inverse-variance weighted meta-analysis, and cumulative proportions as products of adjacent step proportions. We identified 23 studies published between 1986 and 2014, conducted in 12 states and 15 cities. Among studies using tuberculin skin tests (TST) we found that 93.7% (CI 72.4-100%) of persons reached were recruited, 97.9% (89.3-100%) of those recruited had tests placed, 85.5% (78.6-91.3%) of those with tests placed returned for reading, 99.9% (99.6-100%) of those with tests read had valid results, and 24.7% (21.0-28.5%) with valid results tested positive. All persons testing positive were referred to follow-up care, and 99.8% attended at least one session of follow-up care. Heterogeneity was high for most pooled proportions. For a hypothetical cohort of 1000 persons experiencing homelessness reached by a targeted testing program using TST, an estimated 917 were tested, 194 were positive, and all of these initiated follow-up care. Targeted TB testing of persons experiencing homelessness appears effective in detecting LTBI and connecting persons to care and potential treatment. Future evaluations should assess diagnostic use of interferon gamma release assays and completion of

  12. Two energy system analysis - cases

    DEFF Research Database (Denmark)

    Lund, Henrik; Antonoff, Jayson; Andersen, Anders N.

    2004-01-01

    The chapter presents tow cases of energy system analysis, illustrating the types of tools and methodologies presently being used for these studies in Denamrk and elsewhere.......The chapter presents tow cases of energy system analysis, illustrating the types of tools and methodologies presently being used for these studies in Denamrk and elsewhere....

  13. Cascading Failures as Continuous Phase-Space Transitions

    Science.gov (United States)

    Yang, Yang; Motter, Adilson E.

    2017-12-01

    In network systems, a local perturbation can amplify as it propagates, potentially leading to a large-scale cascading failure. Here we derive a continuous model to advance our understanding of cascading failures in power-grid networks. The model accounts for both the failure of transmission lines and the desynchronization of power generators and incorporates the transient dynamics between successive steps of the cascade. In this framework, we show that a cascade event is a phase-space transition from an equilibrium state with high energy to an equilibrium state with lower energy, which can be suitably described in a closed form using a global Hamiltonian-like function. From this function, we show that a perturbed system cannot always reach the equilibrium state predicted by quasi-steady-state cascade models, which would correspond to a reduced number of failures, and may instead undergo a larger cascade. We also show that, in the presence of two or more perturbations, the outcome depends strongly on the order and timing of the individual perturbations. These results offer new insights into the current understanding of cascading dynamics, with potential implications for control interventions.

  14. A thermal modelling of displacement cascades in uranium dioxide

    Science.gov (United States)

    Martin, G.; Garcia, P.; Sabathier, C.; Devynck, F.; Krack, M.; Maillard, S.

    2014-05-01

    The space and time dependent temperature distribution was studied in uranium dioxide during displacement cascades simulated by classical molecular dynamics (MD). The energy for each simulated radiation event ranged between 0.2 keV and 20 keV in cells at initial temperatures of 700 K or 1400 K. Spheres into which atomic velocities were rescaled (thermal spikes) have also been simulated by MD to simulate the thermal excitation induced by displacement cascades. Equipartition of energy was shown to occur in displacement cascades, half of the kinetic energy of the primary knock-on atom being converted after a few tenths of picoseconds into potential energy. The kinetic and potential parts of the system energy are however subjected to little variations during dedicated thermal spike simulations. This is probably due to the velocity rescaling process, which impacts a large number of atoms in this case and would drive the system away from a dynamical equilibrium. This result makes questionable MD simulations of thermal spikes carried out up to now (early 2014). The thermal history of cascades was compared to the heat equation solution of a punctual thermal excitation in UO2. The maximum volume brought to a temperature above the melting temperature during the simulated cascade events is well reproduced by this simple model. This volume eventually constitutes a relevant estimate of the volume affected by a displacement cascade in UO2. This definition of the cascade volume could also make sense in other materials, like iron.

  15. Multi-elemental analysis of atmospheric pollutants and determination of particle size using the PIXE method, a cascade impactor and a filter unit constructed in Mexico

    International Nuclear Information System (INIS)

    Aldape U, F.

    1989-01-01

    This work presents: 1) The methodology and the experimental conditions of the PIXE technique so that it is used as a better option inside the analytical methods in aerosols studies, 2) The development, tests and applications of a cascade impactor of the Batelle type built to determine particle size to use it jointly with the mentioned technique in the determination of the elements concentration according to its size.By this way is fulfilled with the first goal of this extensive project. (Author)

  16. Assessment of 50%-Propagation-Delay for Cascaded PCB Non-Linear Interconnect Lines for the High-Rate Signal Integrity Analysis

    OpenAIRE

    T. Eudes; B. Ravelo; R. Al-Hayek

    2013-01-01

    This paper presents an enlarged study about the 50-% propagation-time assessment of cascaded transmission lines (TLs). First and foremost, the accurate modeling and measurement technique of signal integrity (SI) for high-rate microelectronic interconnection is recalled. This model is based on the reduced transfer function extracted from the electromagnetic (EM) behavior of the interconnect line RLCG-parameters. So, the transfer function established takes into account both the frequency disper...

  17. Rietveld analysis system RIETAN (translation)

    International Nuclear Information System (INIS)

    Izumi, Fujio

    1991-09-01

    This is the manual of the RIETAN system (a Rietveld analysis program) which is originally written in Japanese by Fujio Izumi. The manual consists of two parts. Part I is a general description of the fundamental concepts and methods of the RIETAN system. Part II is the user's manual of the RIETAN which mainly describes in detail how to create user's data sets, procedures of Rietveld analysis and how to read the results of analysis. (author)

  18. Image coding design considerations for cascaded encoding-decoding cycles and image editing: analysis of JPEG 1, JPEG 2000, and JPEG XR / HD Photo

    Science.gov (United States)

    Sullivan, Gary J.; Sun, Shijun; Regunathan, Shankar; Schonberg, Daniel; Tu, Chengjie; Srinivasan, Sridhar

    2008-08-01

    This paper discusses cascaded multiple encoding/decoding cycles and their effect on image quality for lossy image coding designs. Cascaded multiple encoding/decoding is an important operating scenario in professional editing industries. In such scenarios, it is common for a single image to be edited by several people while the image is compressed between editors for transit and archival. In these cases, it is important that decoding followed by re-encoding introduce minimal (or no) distortion across generations. A significant number of potential sources of distortion introduction exist in a cascade of decoding and re-encoding, especially if such processes as conversion between RGB and YUV color representations, 4:2:0 resampling, etc., are considered (and operations like spatial shifting, resizing, and changes of the quantization process or coding format). This paper highlights various aspects of distortion introduced by decoding and re-encoding, and remarks on the impact of these issues in the context of three still-image coding designs: JPEG, JPEG 2000, and JPEG XR. JPEG XR is a draft standard under development in the JPEG committee based on Microsoft technology known as HD Photo. The paper focuses particularly on the JPEG XR technology, and suggests that the design of the draft JPEG XR standard has several quite good characteristics in regard to re-encoding robustness.

  19. Integrated system reliability analysis

    DEFF Research Database (Denmark)

    Gintautas, Tomas; Sørensen, John Dalsgaard

    Specific targets: 1) The report shall describe the state of the art of reliability and risk-based assessment of wind turbine components. 2) Development of methodology for reliability and risk-based assessment of the wind turbine at system level. 3) Describe quantitative and qualitative measures...... (indicators) that can be used to assess the reliability of innovations and new technologies....

  20. Data Systems Task Analysis.

    Science.gov (United States)

    1979-08-01

    QUALITY CCNTROL SUPERVISOR/NCOIC 369. PROGRAMMER 07?. PROGRAMMER ANALYST C7l, PROGRAMMING/ANALYSIS SUPERVISCR 󈨌. UALITY CONTROL PETTY OFFICER/CLERK...CLASSIFICATION OF THE FACILITY OR SITE THAT YOU ARE PRESENTLY WORKING IN? 01. CDPA (CENTRAL DESIGN PROGRAMMING ACTIVITY) 02. RASC (REGIONAL AUTOMATED...CARDS MANUALLY I)9. COORDINATE WITH CfFICES CF PFIMARY RESPONSIBILITY (OPR) ON NEW OR REVISED REPORTING REQUIREMENTS 115. DETERMINE ALTERNATE METHODS

  1. Systems analysis with an integrated medical analysis system (IMAS)

    Science.gov (United States)

    Koelsch, John; Mabry, Susan L.; Rodriquez, Samuel; Takemura, Paul

    1998-05-01

    This paper describes the integrated medical analysis system (IMAS) The evolving system consists of an integrated suite of models and tools providing quantitative and dynamic analysis from multiple physiological function models, clinical care patient input, medical device data, and integrated medical systems. The system is being developed for requirements definition, patient assessment, control theory, training, instrumentation testing and validation. Traditionally, human models and simulations are performed on small scale, isolated problems, usually consisting of detached mathematical models or measurements studies. These systems are not capable of portraying the interactive effects of such systems and certainly are not capable of integrating multiple external entities such as device data, patient data, etc. The human body in and of itself is a complex, integrated system. External monitors, treatments, and medical conditions interact at yet another level. Hence, a highly integrated, interactive simulation system with detailed subsystem models is required for effective quantitative analysis. The current prototype emphasizes cardiovascular, respiratory and thermoregulatory functions with integration of patient device data. Unique system integration of these components is achieved through four facilitators. These facilitators include a distributed interactive computing architecture, application of fluid and structural engineering principles to the models, real-time scientific visualization, and application of strong system integration principles. The IMAS forms a complex analytical tool with emphasis on integration and interaction at multiple levels between components. This unique level of integration and interaction facilitates quantitative analysis for multiple purposes and varying levels of fidelity. An overview of the project and preliminary findings are introduced.

  2. Inferring network structure from cascades

    Science.gov (United States)

    Ghonge, Sushrut; Vural, Dervis Can

    2017-07-01

    Many physical, biological, and social phenomena can be described by cascades taking place on a network. Often, the activity can be empirically observed, but not the underlying network of interactions. In this paper we offer three topological methods to infer the structure of any directed network given a set of cascade arrival times. Our formulas hold for a very general class of models where the activation probability of a node is a generic function of its degree and the number of its active neighbors. We report high success rates for synthetic and real networks, for several different cascade models.

  3. Arctic Climate Systems Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ivey, Mark D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Robinson, David G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Boslough, Mark B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Backus, George A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Peterson, Kara J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); van Bloemen Waanders, Bart G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Swiler, Laura Painton [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Desilets, Darin Maurice [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Reinert, Rhonda Karen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-03-01

    This study began with a challenge from program area managers at Sandia National Laboratories to technical staff in the energy, climate, and infrastructure security areas: apply a systems-level perspective to existing science and technology program areas in order to determine technology gaps, identify new technical capabilities at Sandia that could be applied to these areas, and identify opportunities for innovation. The Arctic was selected as one of these areas for systems level analyses, and this report documents the results. In this study, an emphasis was placed on the arctic atmosphere since Sandia has been active in atmospheric research in the Arctic since 1997. This study begins with a discussion of the challenges and benefits of analyzing the Arctic as a system. It goes on to discuss current and future needs of the defense, scientific, energy, and intelligence communities for more comprehensive data products related to the Arctic; assess the current state of atmospheric measurement resources available for the Arctic; and explain how the capabilities at Sandia National Laboratories can be used to address the identified technological, data, and modeling needs of the defense, scientific, energy, and intelligence communities for Arctic support.

  4. Risk Assessment of Cascading Outages: Methodologies and Challenges

    Energy Technology Data Exchange (ETDEWEB)

    Vaiman, Marianna; Bell, Keith; Chen, Yousu; Chowdhury, Badrul; Dobson, Ian; Hines, Paul; Papic, Milorad; Miller, Stephen; Zhang, Pei

    2012-05-31

    Abstract- This paper is a result of ongoing activity carried out by Understanding, Prediction, Mitigation and Restoration of Cascading Failures Task Force under IEEE Computer Analytical Methods Subcommittee (CAMS). The task force's previous papers are focused on general aspects of cascading outages such as understanding, prediction, prevention and restoration from cascading failures. This is the first of two new papers, which extend this previous work to summarize the state of the art in cascading failure risk analysis methodologies and modeling tools. This paper is intended to be a reference document to summarize the state of the art in the methodologies for performing risk assessment of cascading outages caused by some initiating event(s). A risk assessment should cover the entire potential chain of cascades starting with the initiating event(s) and ending with some final condition(s). However, this is a difficult task and heuristic approaches and approximations have been suggested. This paper discusses different approaches to this and suggests directions for future development of methodologies. The second paper summarizes the state of the art in modeling tools for risk assessment of cascading outages.

  5. Systems analysis-independent analysis and verification

    Energy Technology Data Exchange (ETDEWEB)

    Badin, J.S.; DiPietro, J.P. [Energetics, Inc., Columbia, MD (United States)

    1995-09-01

    The DOE Hydrogen Program is supporting research, development, and demonstration activities to overcome the barriers to the integration of hydrogen into the Nation`s energy infrastructure. Much work is required to gain acceptance of hydrogen energy system concepts and to develop them for implementation. A systems analysis database has been created that includes a formal documentation of technology characterization profiles and cost and performance information. Through a systematic and quantitative approach, system developers can understand and address important issues and thereby assure effective and timely commercial implementation. This project builds upon and expands the previously developed and tested pathway model and provides the basis for a consistent and objective analysis of all hydrogen energy concepts considered by the DOE Hydrogen Program Manager. This project can greatly accelerate the development of a system by minimizing the risk of costly design evolutions, and by stimulating discussions, feedback, and coordination of key players and allows them to assess the analysis, evaluate the trade-offs, and to address any emerging problem areas. Specific analytical studies will result in the validation of the competitive feasibility of the proposed system and identify system development needs. Systems that are investigated include hydrogen bromine electrolysis, municipal solid waste gasification, electro-farming (biomass gasifier and PEM fuel cell), wind/hydrogen hybrid system for remote sites, home electrolysis and alternate infrastructure options, renewable-based electrolysis to fuel PEM fuel cell vehicle fleet, and geothermal energy used to produce hydrogen. These systems are compared to conventional and benchmark technologies. Interim results and findings are presented. Independent analyses emphasize quality, integrity, objectivity, a long-term perspective, corporate memory, and the merging of technical, economic, operational, and programmatic expertise.

  6. Thermodynamic analysis of hydrocarbon refrigerants-based ethylene BOG re-liquefaction system

    Science.gov (United States)

    Beladjine, Boumedienne M.; Ouadha, Ahmed; Addad, Yacine

    2016-09-01

    The present study aims to make a thermodynamic analysis of an ethylene cascade re-liquefaction system that consists of the following two subsystems: a liquefaction cycle using ethylene as the working fluid and a refrigeration cycle operating with a hydrocarbon refrigerant. The hydrocarbon refrigerants considered are propane (R290), butane (R600), isobutane (R600a), and propylene (R1270). A computer program written in FORTRAN is developed to compute parameters for characteristic points of the cycles and the system's performance, which is determined and analyzed using numerical solutions for the refrigerant condensation temperature, temperature in tank, and temperature difference in the cascade condenser. Results show that R600a gives the best performance, followed by (in order) R600, R290, and R1270. Furthermore, it is found that an increase in tank temperature improves system performance but that an increase in refrigerant condensation temperature causes deterioration. In addition, it is found that running the system at a low temperature difference in the cascade condenser is advantageous.

  7. Design-theoretical study of cascade CO2 sub-critical mechanical compression/butane ejector cooling cycle

    KAUST Repository

    Petrenko, V.O.

    2011-11-01

    In this paper an innovative micro-trigeneration system composed of a cogeneration system and a cascade refrigeration cycle is proposed. The cogeneration system is a combined heat and power system for electricity generation and heat production. The cascade refrigeration cycle is the combination of a CO2 mechanical compression refrigerating machine (MCRM), powered by generated electricity, and an ejector cooling machine (ECM), driven by waste heat and using refrigerant R600. Effect of the cycle operating conditions on ejector and ejector cycle performances is studied. Optimal geometry of the ejector and performance characteristics of ECM are determined at wide range of the operating conditions. The paper also describes a theoretical analysis of the CO2 sub-critical cycle and shows the effect of the MCRM evaporating temperature on the cascade system performance. The obtained data provide necessary information to design a small-scale cascade system with cooling capacity of 10 kW for application in micro-trigeneration systems. © 2010 Elsevier Ltd and IIR. All rights reserved.

  8. Vulnerability and Cosusceptibility Determine the Size of Network Cascades

    Science.gov (United States)

    Yang, Yang; Nishikawa, Takashi; Motter, Adilson E.

    2017-01-01

    In a network, a local disturbance can propagate and eventually cause a substantial part of the system to fail in cascade events that are easy to conceptualize but extraordinarily difficult to predict. Here, we develop a statistical framework that can predict cascade size distributions by incorporating two ingredients only: the vulnerability of individual components and the cosusceptibility of groups of components (i.e., their tendency to fail together). Using cascades in power grids as a representative example, we show that correlations between component failures define structured and often surprisingly large groups of cosusceptible components. Aside from their implications for blackout studies, these results provide insights and a new modeling framework for understanding cascades in financial systems, food webs, and complex networks in general.

  9. Ultrarelativistic cascades and strangeness production

    International Nuclear Information System (INIS)

    Kahana, D.E.; Kahana, S.H.

    1998-01-01

    A two-phase cascade code, LUCIFER II, developed for the treatment of ultra high energy-ion-ion collisions is applied to the production of strangeness at SPS energies √(s)=17-20. This simulation is able to simultaneously describe both hard processes such as Drell-Yan and slower, soft processes such as the production of light mesons by separating the dynamics into two steps, a fast cascade involving only the nucleons in the original colliding relativistic ions followed, after an appropriate delay, by a normal multiscattering of the resulting excited baryons and mesons produced virtually in the first step. No energy loss can take place in the short time interval over which the first cascade takes place. The chief result is a reconciliation of the important Drell-Yan measurements with the apparent success of standard cascades to describe the nucleon stopping and meson production in heavy-ion experiments at the CERN SPS. (orig.)

  10. Ultrarelativistic cascades and strangeness production

    Energy Technology Data Exchange (ETDEWEB)

    Kahana, D.E. [State Univ. of New York, Stony Brook, NY (United States). Physics Dept.; Kahana, S.H. [Brookhaven National Lab., Upton, NY (United States). Physics Dept.

    1998-02-01

    A two phase cascade, LUCIFER II, developed for the treatment of ultra high energy Ion-Ion collisions is applied to the production of strangeness at SPS energies. This simulation is able to simultaneously describe both hard processes such as Drell-Yan and slower, soft processes such as the production of light mesons by separating the dynamics into two steps, a fast cascade involving only the nucleons in the original colliding relativistic ions followed, after an appropriate delay, by a normal multiscattering of the resulting excited baryons and mesons produced virtually in the first step. No energy loss can take place in the short time interval over which the first cascade takes place. The chief result is a reconciliation of the important Drell-Yan measurements with the apparent success of standard cascades to describe the nucleon stopping and meson production in heavy ion experiments at the CERN SPS.

  11. Ultrarelativistic cascades and strangeness production

    International Nuclear Information System (INIS)

    Kahana, D.E.; Kahana, S.H.

    1998-02-01

    A two phase cascade, LUCIFER II, developed for the treatment of ultra high energy Ion-Ion collisions is applied to the production of strangeness at SPS energies. This simulation is able to simultaneously describe both hard processes such as Drell-Yan and slower, soft processes such as the production of light mesons by separating the dynamics into two steps, a fast cascade involving only the nucleons in the original colliding relativistic ions followed, after an appropriate delay, by a normal multiscattering of the resulting excited baryons and mesons produced virtually in the first step. No energy loss can take place in the short time interval over which the first cascade takes place. The chief result is a reconciliation of the important Drell-Yan measurements with the apparent success of standard cascades to describe the nucleon stopping and meson production in heavy ion experiments at the CERN SPS

  12. SUBSURFACE VISUAL ALARM SYSTEM ANALYSIS

    International Nuclear Information System (INIS)

    D.W. Markman

    2001-01-01

    The ''Subsurface Fire Hazard Analysis'' (CRWMS M andO 1998, page 61), and the document, ''Title III Evaluation Report for the Surface and Subsurface Communication System'', (CRWMS M andO 1999a, pages 21 and 23), both indicate the installed communication system is adequate to support Exploratory Studies Facility (ESF) activities with the exception of the mine phone system for emergency notification purposes. They recommend the installation of a visual alarm system to supplement the page/party phone system The purpose of this analysis is to identify data communication highway design approaches, and provide justification for the selected or recommended alternatives for the data communication of the subsurface visual alarm system. This analysis is being prepared to document a basis for the design selection of the data communication method. This analysis will briefly describe existing data or voice communication or monitoring systems within the ESF, and look at how these may be revised or adapted to support the needed data highway of the subsurface visual alarm. system. The existing PLC communication system installed in subsurface is providing data communication for alcove No.5 ventilation fans, south portal ventilation fans, bulkhead doors and generator monitoring system. It is given that the data communication of the subsurface visual alarm system will be a digital based system. It is also given that it is most feasible to take advantage of existing systems and equipment and not consider an entirely new data communication system design and installation. The scope and primary objectives of this analysis are to: (1) Briefly review and describe existing available data communication highways or systems within the ESF. (2) Examine technical characteristics of an existing system to disqualify a design alternative is paramount in minimizing the number of and depth of a system review. (3) Apply general engineering design practices or criteria such as relative cost, and degree

  13. Stochastic background of atmospheric cascades

    International Nuclear Information System (INIS)

    Wilk, G.; Wlodarczyk, Z.

    1993-01-01

    Fluctuations in the atmospheric cascades developing during the propagation of very high energy cosmic rays through the atmosphere are investigated using stochastic branching model of pure birth process with immigration. In particular, we show that the multiplicity distributions of secondaries emerging from gamma families are much narrower than those resulting from hadronic families. We argue that the strong intermittent like behaviour found recently in atmospheric families results from the fluctuations in the cascades themselves and are insensitive to the details of elementary interactions

  14. PLACE OF PRODUCTION COSTS SYSTEM ANALYSIS IN SYSTEM ANALYSIS

    Directory of Open Access Journals (Sweden)

    Mariia CHEREDNYCHENKO

    2016-12-01

    Full Text Available Current economic conditions require the development and implementation of an adequate system of production costs, which would ensure a steady profit growth and production volumes in a highly competitive, constantly increasing input prices and tariffs. This management system must be based on an integrated production costs system analysis (PCSA, which would provide all operating costs management subsystems necessary information to design and make better management decisions. It provides a systematic analysis of more opportunities in knowledge, creating conditions of integrity mechanism knowledge object consisting of elements that show intersystem connections, each of which has its own defined and limited objectives, relationship with the environment.

  15. Demonstration of two-user, 10-Gbits/s optical code-division multiple-access system implemented by using cascaded longperiod fiber gratings formed in dispersion-compensating fiber with inner-cladding structure

    DEFF Research Database (Denmark)

    Kim, Sun-Jong; Eom, T.J.; Kim, T.Y.

    2005-01-01

    A two-user, 10-Gbits/s optical code-division multiple-access system implemented by using cascaded long-period fiber gratings formed in a dispersion-compensating fiber (DCF) is demonstrated. Our results show that the sensitivity of cladding modes to the refractive index change on the cladding...... surface is greatly reduced by utilizing the inner-cladding mode of the DCF. Two pairs of encoder/decoder are constructed and the performance is evaluated by measuring bit error rate (BER). With an interferer, a BER of 1.5 X 10(-12) is measured at a received optical power of -6 dBm....

  16. Demonstration of two-user, 10-Gbits/s optical code-division multiple-access system implemented by using cascaded long-period fiber gratings formed in dispersion-compensating fiber with inner-cladding structure

    Science.gov (United States)

    Kim, Sun-Jong; Eom, Tae-Jung; Kim, Tae-Young; Lee, Byeong Ha; Park, Chang-Soo

    2005-09-01

    A two-user, 10-Gbits/s optical code-division multiple-access system implemented by using cascaded long-period fiber gratings formed in a dispersion-compensating fiber (DCF) is demonstrated. Our results show that the sensitivity of cladding modes to the refractive index change on the cladding surface is greatly reduced by utilizing the inner-cladding mode of the DCF. Two pairs of encoder/decoder are constructed and the performance is evaluated by measuring bit error rate (BER). With an interferer, a BER of 1.5×10-12 is measured at a received optical power of -6 dBm.

  17. Cascade Apartments: Deep Energy Multifamily Retrofit

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, A. [Washington State Univ. Energy Program, Olympia, WA (United States); Mattheis, L. [Washington State Univ. Energy Program, Olympia, WA (United States); Kunkle, R. [Washington State Univ. Energy Program, Olympia, WA (United States); Howard, L. [Washington State Univ. Energy Program, Olympia, WA (United States); Lubliner, M. [Washington State Univ. Energy Program, Olympia, WA (United States)

    2014-02-01

    In December of 2009-10, King County Housing Authority (KCHA) implemented energy retrofit improvements in the Cascade multifamily community, located in Kent, Washington (marine climate.)This research effort involved significant coordination from stakeholders KCHA, WA State Department of Commerce, utility Puget Sound Energy, and Cascade tenants. This report focuses on the following three primary BA research questions: 1. What are the modeled energy savings using DOE low income weatherization approved TREAT software? 2. How did the modeled energy savings compare with measured energy savings from aggregate utility billing analysis? 3. What is the Savings to Investment Ratio (SIR) of the retrofit package after considering utility window incentives and KCHA capitol improvement funding.

  18. Cascade Apartments: Deep Energy Multifamily Retrofit

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, A. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Mattheis, L. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Kunkle, R. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Howard, L. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lubliner, M. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2014-02-01

    In December of 2009-10, King County Housing Authority (KCHA) implemented energy retrofit improvements in the Cascade multifamily community, located in Kent, Washington (marine climate.)This research effort involved significant coordination from stakeholders KCHA, WA State Department of Commerce, utility Puget Sound Energy, and Cascade tenants. This report focuses on the following three primary BA research questions : 1. What are the modeled energy savings using DOE low income weatherization approved TREAT software? 2. How did the modeled energy savings compare with measured energy savings from aggregate utility billing analysis? 3. What is the Savings to Investment Ratio (SIR) of the retrofit package after considering utility window incentives and KCHA capitol improvement funding.

  19. Computer codes for simulating atomic-displacement cascades in solids subject to irradiation

    International Nuclear Information System (INIS)

    Asaoka, Takumi; Taji, Yukichi; Tsutsui, Tsuneo; Nakagawa, Masayuki; Nishida, Takahiko

    1979-03-01

    In order to study atomic displacement cascades originating from primary knock-on atoms in solids subject to incident radiation, the simulation code CASCADE/CLUSTER is adapted for use on FACOM/230-75 computer system. In addition, the code is modified so as to plot the defect patterns in crystalline solids. As other simulation code of the cascade process, MARLOWE is also available for use on the FACOM system. To deal with the thermal annealing of point defects produced in the cascade process, the code DAIQUIRI developed originally for body-centered cubic crystals is modified to be applicable also for face-centered cubic lattices. By combining CASCADE/CLUSTER and DAIQUIRI, we then prepared a computer code system CASCSRB to deal with heavy irradiation or saturation damage state of solids at normal temperature. Furthermore, a code system for the simulation of heavy irradiations CASCMARL is available, in which MARLOWE code is substituted for CASCADE in the CASCSRB system. (author)

  20. Computerized ECT data analysis system

    International Nuclear Information System (INIS)

    Miyake, Y.; Fukui, S.; Iwahashi, Y.; Matsumoto, M.; Koyama, K.

    1988-01-01

    For the analytical method of the eddy current testing (ECT) of steam generator tubes in nuclear power plants, the authors have developed the computerized ECT data analysis system using a large-scale computer with a high-resolution color graphic display. This system can store acquired ECT data up to 15 steam generators, and ECT data can be analyzed immediately on the monitor in dialogue communication with a computer. Analyzed results of ECT data are stored and registered in the data base. This system enables an analyst to perform sorting and collecting of data under various conditions and obtain the results automatically, and also to make a plan of tube repair works. This system has completed the test run, and has been used for data analysis at the annual inspection of domestic plants. This paper describes an outline, features and examples of the computerized eddy current data analysis system for steam generator tubes in PWR nuclear power plants

  1. Biexciton cascade emission in multilayered organic nanofibers

    Science.gov (United States)

    Evaristo de Sousa, Leonardo; Ferreira da Cunha, Wiliam; Antônio da Silva Filho, Demétrio; de Oliveira Neto, Pedro Henrique

    2018-04-01

    The optical performance of multilayered organic nanofibers results from the dynamics of excited states in the system. Here, we show that the presence of biexcitons is crucial to correctly describe such dynamics. This may be the case even if the intensity of the light source is not high. The cascade emission mediated by biexcitons is mainly responsible for the behavior of the photoluminescence profile in the initial steps after light absorption. By using a combination of Kinetic Monte Carlo model and Genetic Algorithm, we simulate Time-Resolved Photoluminescence measurements of multilayered nanofibers. These simulations are compared with experimental results, thus revealing that the usual singlet exciton recombination is insufficient to reproduce the complete physical picture. Our results also include predictions for the behavior of the biexciton signal. These findings are observed to be valid for a wide temperature range, showing the importance of the biexciton cascade emission in several regimes for organic nanofibers in general.

  2. Cascaded impedance networks for NPC inverter

    DEFF Research Database (Denmark)

    Li, Ding; Gao, Feng; Loh, Poh Chiang

    2010-01-01

    Multilevel inverters are getting more and more attracted because they have better output waveform quality and lower semiconductor voltage stress. The Z-source NPC is a kind of single stage multilevel inverter which has the ability of voltage boost. But the boost capability is relatively low when...... they are subject to the renewable sources. To date, three distinct types of impedance networks can be summarized for implementing a hybrid source impedance network, which can in principle be combined and cascaded before connected to a NPC inverter by proposed two ways. The resulting cascaded impedance network NPC...... would have a higher output voltage gain. It is anticipated that it would help the formed inverters find applications in photovoltaic and other renewable systems, where a high voltage gain is usually requested. Experimental testing has already been conducted and verifies the theory....

  3. Cascadable spatial-soliton logic gates.

    Science.gov (United States)

    Blair, S; Wagner, K

    2000-11-10

    The three-terminal spatial-soliton angular-deflection geometry provides the characteristics of an inverting logic gate with gain, and phase-insensitive implementations can be realized by a number of specific nonlinear interactions between orthogonally polarized waves. In particular, numerical simulations of spatial-soliton dragging and collision are used to calculate the transfer functions of inverter and multiple configurations of two-input nor gates and to address their cascadability. These transfer functions converge in cascaded operation and suggest that fan-out greater than 2 with a large noise margin is attainable in a system with standardized signal levels. These results are obtained with the material properties of fused silica and are representative of low-loss Kerr media.

  4. Bounded Target Cascading in Hierarchical Design Optimization

    Directory of Open Access Journals (Sweden)

    Xiaoling Zhang

    2014-06-01

    Full Text Available For large scale systems, as a hierarchical multilevel decomposed design optimization method, analytical target cascading coordinates the inconsistency between the assigned targets and response in each level by a weighted-sum formulation. To avoid the problems associated with the weighting coefficients, single objective functions in the hierarchical design optimization are formulated by a bounded target cascading method in this paper. In the BTC method, a single objective optimization problem is formulated in the system level, and two kinds of coordination constraints are added: one is bound constraint for the design points based on the response from each subsystem level and the other is linear equality constraint for the common variables based on their sensitivities with respect to each subsystem. In each subsystem level, the deviation with target for design point is minimized in the objective function, and the common variables are constrained by target bounds. Therefore, in the BTC method, the targets are coordinated based on the optimization iteration information in the hierarchical design problem and the performance of the subsystems, and BTC method will converge to the global optimum efficiently. Finally, comparisons of the results from BTC method and the weighted-sum analytical target cascading method are presented and discussed.

  5. From HIV infection to therapeutic response: a population-based longitudinal HIV cascade-of-care study in KwaZulu-Natal, South Africa.

    Science.gov (United States)

    Haber, Noah; Tanser, Frank; Bor, Jacob; Naidu, Kevindra; Mutevedzi, Tinofa; Herbst, Kobus; Porter, Kholoud; Pillay, Deenan; Bärnighausen, Till

    2017-05-01

    Standard approaches to estimation of losses in the HIV cascade of care are typically cross-sectional and do not include the population stages before linkage to clinical care. We used indiviual-level longitudinal cascade data, transition by transition, including population stages, both to identify the health-system losses in the cascade and to show the differences in inference between standard methods and the longitudinal approach. We used non-parametric survival analysis to estimate a longitudinal HIV care cascade for a large population of people with HIV residing in rural KwaZulu-Natal, South Africa. We linked data from a longitudinal population health surveillance (which is maintained by the Africa Health Research Institute) with patient records from the local public-sector HIV treatment programme (contained in an electronic clinical HIV treatment and care database, ARTemis). We followed up all people who had been newly detected as having HIV between Jan 1, 2006, and Dec 31, 2011, across six cascade stages: three population stages (first positive HIV test, HIV status knowledge, and linkage to care) and three clinical stages (eligibility for antiretroviral therapy [ART], initiation of ART, and therapeutic response). We compared our estimates to cross-sectional cascades in the same population. We estimated the cumulative incidence of reaching a particular cascade stage at a specific time with Kaplan-Meier survival analysis. Our population consisted of 5205 individuals with HIV who were followed up for 24 031 person-years. We recorded 598 deaths. 4539 individuals gained knowledge of their positive HIV status, 2818 were linked to care, 2151 became eligible for ART, 1839 began ART, and 1456 had successful responses to therapy. We used Kaplan-Meier survival analysis to adjust for censorship due to the end of data collection, and found that 8 years after testing positive in the population health surveillance, 16% had died. Among living patients, 82% knew their HIV

  6. An automated activation analysis system

    International Nuclear Information System (INIS)

    Minor, M.M.; Hensley, W.K.; Denton, M.M.; Garcia, S.R.

    1982-01-01

    An automated delayed neutron counting and instrumental neutron activation analysis system has been developed at Los Alamos National Laboratory's Omega West Reactor (OWR) to analyze samples for uranium and 31 additional elements with a maximum throughput of 400 samples per day. The system and its mode of operation for a large reconnaissance survey will be described. (author)

  7. Automated activation-analysis system

    International Nuclear Information System (INIS)

    Minor, M.M.; Hensley, W.K.; Denton, M.M.; Garcia, S.R.

    1981-01-01

    An automated delayed neutron counting and instrumental neutron activation analysis system has been developed at Los Alamos National Laboratory's Omega West Reactor (OWR) to analyze samples for uranium and 31 additional elements with a maximum throughput of 400 samples per day. The system and its mode of operation for a large reconnaissance survey are described

  8. Static Analysis for Systems Biology

    DEFF Research Database (Denmark)

    Nielson, Flemming; Nielson, Hanne Riis; Rosa, D. Schuch da

    2004-01-01

    This paper shows how static analysis techniques can help understanding biological systems. Based on a simple example we illustrate the outcome of performing three different analyses extracting information of increasing precision. We conclude by reporting on the potential impact and exploitation o...... of these techniques in systems biology....

  9. Basic characteristics of a low uranium enrichment cascade by centrifugation, (2)

    International Nuclear Information System (INIS)

    Kai, Tsunetoshi

    1975-01-01

    The theory for a cascade of centrifuges described in the preceding report of the same general title is further developed. First, equations describing the distributions of the flow and the mole concentration are derived from the material balance relations for a square cascade. Corresponding equations are next obtained to cover a squared-off cascade consisting of a series of square cascades. A computer program is outlined which makes it possible to obtain the shape of the most efficient squared-off cascade. The efficiency of the current form of squared-off centrifuge cascade with reflux pipes is found to be lower than obtainable with gaseous diffusion. The efficiency can be improved by the adoption of a tapered squared-off cascade with centrifuges provided with eccentric cuts to take the place of reflux pipes. The dynamic characteristics are also discussed. Analysis of the start-up behavior reveals that the equilibrium time of the centrifuge cascade is much shorter than for a coresponding gaseous diffusion cascade, and that the mole concentration of the product rapidly rises to attain steady state condition. It is also found that even when the feed flow rate fluctuates, the mole concentration of the product is relatively stable. The effect of a centrifuge failure in the cascade is examined. The optimum mole concentration for the waste effluent discarded from the cascade is calculated from the viewpoint of cost. (auth.)

  10. Noise and vibration analysis system

    International Nuclear Information System (INIS)

    Johnsen, J.R.; Williams, R.L.

    1985-01-01

    The analysis of noise and vibration data from an operating nuclear plant can provide valuable information that can identify and characterize abnormal conditions. Existing plant monitoring equipment, such as loose parts monitoring systems (LPMS) and neutron flux detectors, may be capable of gathering noise data, but may lack the analytical capability to extract useful meanings hidden in the noise. By analyzing neutron noise signals, the structural motion and integrity of core components can be assessed. Computer analysis makes trending of frequency spectra within a fuel cycle and from one cycle to another a practical means of core internals monitoring. The Babcock and Wilcox Noise and Vibration Analysis System (NVAS) is a powerful, compact system that can automatically perform complex data analysis. The system can acquire, process, and store data, then produce report-quality plots of the important parameter. Software to perform neutron noise analysis and loose parts analysis operates on the same hardware package. Since the system is compact, inexpensive, and easy to operate, it allows utilities to perform more frequency analyses without incurring high costs and provides immediate results

  11. The ALICE analysis train system

    CERN Document Server

    Zimmermann, Markus

    2015-01-01

    In the ALICE experiment hundreds of users are analyzing big datasets on a Grid system. High throughput and short turn-around times are achieved by a centralized system called the LEGO trains. This system combines analysis from different users in so-called analysis trains which are then executed within the same Grid jobs thereby reducing the number of times the data needs to be read from the storage systems. The centralized trains improve the performance, the usability for users and the bookkeeping in comparison to single user analysis. The train system builds upon the already existing ALICE tools, i.e. the analysis framework as well as the Grid submission and monitoring infrastructure. The entry point to the train system is a web interface which is used to configure the analysis and the desired datasets as well as to test and submit the train. Several measures have been implemented to reduce the time a train needs to finish and to increase the CPU efficiency.

  12. Cascade of circulations in fluid turbulence.

    Science.gov (United States)

    Eyink, Gregory L

    2006-12-01

    Kelvin's theorem on conservation of circulations is an essential ingredient of Taylor's theory of turbulent energy dissipation by the process of vortex-line stretching. In previous work, we have proposed a nonlinear mechanism for the breakdown of Kelvin's theorem in ideal turbulence at infinite Reynolds number. We develop here a detailed physical theory of this cascade of circulations. Our analysis is based upon an effective equation for large-scale coarse-grained velocity, which contains a turbulent-induced vortex force that can violate Kelvin's theorem. We show that singularities of sufficient strength, which are observed to exist in turbulent flow, can lead to nonvanishing dissipation of circulation for an arbitrarily small coarse-graining length in the effective equations. This result is an analog for circulation of Onsager's theorem on energy dissipation for singular Euler solutions. The physical mechanism of the breakdown of Kelvin's theorem is diffusion of lines of large-scale vorticity out of the advected loop. This phenomenon can be viewed as a classical analog of the Josephson-Anderson phase-slip phenomenon in superfluids due to quantized vortex lines. We show that the circulation cascade is local in scale and use this locality to develop concrete expressions for the turbulent vortex force by a multiscale gradient expansion. We discuss implications for Taylor's theory of turbulent dissipation and we point out some related cascade phenomena, in particular for magnetic flux in magnetohydrodynamic turbulence.

  13. Signal transduction in a covalent post-assembly modification cascade

    Science.gov (United States)

    Pilgrim, Ben S.; Roberts, Derrick A.; Lohr, Thorsten G.; Ronson, Tanya K.; Nitschke, Jonathan R.

    2017-12-01

    Natural reaction cascades control the movement of biomolecules between cellular compartments. Inspired by these systems, we report a synthetic reaction cascade employing post-assembly modification reactions to direct the partitioning of supramolecular complexes between phases. The system is composed of a self-assembled tetrazine-edged FeII8L12 cube and a maleimide-functionalized FeII4L6 tetrahedron. Norbornadiene (NBD) functions as the stimulus that triggers the cascade, beginning with the inverse-electron-demand Diels-Alder reaction of NBD with the tetrazine moieties of the cube. This reaction generates cyclopentadiene as a transient by-product, acting as a relay signal that subsequently undergoes a Diels-Alder reaction with the maleimide-functionalized tetrahedron. Cyclooctyne can selectively inhibit the cascade by outcompeting NBD as the initial trigger. Initiating the cascade with 2-octadecyl NBD leads to selective alkylation of the tetrahedron upon cascade completion. The increased lipophilicity of the C18-tagged tetrahedron drives this complex into a non-polar phase, allowing its isolation from the initially inseparable mixture of complexes.

  14. Time structure of cascade showers

    International Nuclear Information System (INIS)

    Nakatsuka, Takao

    1984-01-01

    Interesting results have been reported on the time structure of the electromagnetic components of air showers which have been obtained by using recent fast electronic circuit technology. However, these analyses and explanations seem not very persuasive. One of the reasons is that there is not satisfactory theoretical calculation yet to explain the delay of electromagnetic components in cascade processes which are the object of direct observation. Therefore, Monte Carlo calculation was attempted for examining the relationship between the altitude at which high energy γ-ray is generated up in the air and the time structure of cascade showers at the level of observation. The investigation of a dominant factor over the delay of electromagnetic components indicated that the delay due to the multiple scattering of electrons was essential. The author used the analytical solution found by himself of C. N. Yang's equation for the study on the delay due to multiple scattering. The results were as follows: The average delay time and the spread of distribution of electromagnetic cascades were approximately in linear relationship with the mass of a material having passed in a thin uniform medium; the rise time of arrival time distribution for electromagnetic cascade showers was very steep under the condition that they were generated up in the air and observed on the ground; the subpeaks delayed by tens of ns in arrival time may sometimes appear due to the perturbation in electromagnetic cascade processes. (Wakatsuki, Y.)

  15. Distribution system modeling and analysis

    CERN Document Server

    Kersting, William H

    2001-01-01

    For decades, distribution engineers did not have the sophisticated tools developed for analyzing transmission systems-often they had only their instincts. Things have changed, and we now have computer programs that allow engineers to simulate, analyze, and optimize distribution systems. Powerful as these programs are, however, without a real understanding of the operating characteristics of a distribution system, engineers using the programs can easily make serious errors in their designs and operating procedures. Distribution System Modeling and Analysis helps prevent those errors. It gives readers a basic understanding of the modeling and operating characteristics of the major components of a distribution system. One by one, the author develops and analyzes each component as a stand-alone element, then puts them all together to analyze a distribution system comprising the various shunt and series devices for power-flow and short-circuit studies. He includes the derivation of all models and includes many num...

  16. Requirements analysis and system design

    CERN Document Server

    Maciaszek, Leszek A

    2007-01-01

    An examination of the methods and techniques used in the analysis and design phases of Information System development. Emphasis is placed upon the application of object technology in enterprise information systems (EIS) with UML being used throughout. Through its excellent balance of practical explanation and theoretical insight the book manages to avoid unnecessary, complicating details without sacrificing rigor. Examples of real-world scenarios are used throughout, giving the reader an understanding of what really goes on within the field of Software Engineering.

  17. Molecular dynamics simulation of displacement cascades in iron-alpha

    International Nuclear Information System (INIS)

    Vascon, R.

    1997-01-01

    Radiation damage by neutrons or ions in bcc iron has been investigated by molecular dynamics simulations using an embedded atom type many-body potential (EAM). Displacement cascades with energies of 1 to 30 keV were generated in the microcanonical system where the number of atoms (up to 1.5 million) is chosen high enough to compensate the fact that the dissipation of energy is not taken into account in our model. The defect number at the end of cascade lifetime was found to be 60 percent of the NRT standard value. This tendency is in good agreement with experimental data. However, compared with other simulations in iron, we found significant differences in the defect production and distribution. The comparison with results obtained form simulations of cascades in other metals, leads on the one hand to a higher value of the defect number in bcc iron than in fcc metals like copper or nickel, and on the other hand to a ratio, between the number of replacements and the number of defects, lower in iron ( 100). We observed the transient melting of the core of the cascade during simulations. We showed that a higher value of the initial iron crystal temperature, as the mass difference between the components of an artificial binary alloy Fe-X(X=Al,Sb,Au,U) both produce a 'cascade effect': a decrease of the number of defects and an increase of the number of replacements. We also showed up the quasi-channeling of some atoms in high energy cascades. They are at the origin of sub-cascades formation; as a result they induce an opposite effect to the 'cascade effect'. (author)

  18. Automated activation-analysis system

    International Nuclear Information System (INIS)

    Minor, M.M.; Garcia, S.R.; Denton, M.M.

    1982-01-01

    An automated delayed neutron counting and instrumental neutron activation analysis system has been developed at Los Alamos National Laboratory's Omega West Reactor (OWR) to analyze samples for uranium and 31 additional elements with a maximum throughput of 400 samples per day

  19. New directions for systems analysis

    NARCIS (Netherlands)

    Stamper, R.K.; Felipe, J.

    2000-01-01

    Information systems analysis and design is stagnant. It exists largely as an adjunct to software engineering to facilitate the application of computers. Its fundamental ideas, which have scarcely advanced since the 1950s, are based a paradigm that makes us think with a technical bias. This paper

  20. Cascade plant control by timer method

    International Nuclear Information System (INIS)

    Kiguchi, Takashi; Inoue, Kotaro; Kawai, Toshio; Senoo, Makoto.

    1970-01-01

    The present invention relates to a method of controlling uranium flow rate through a cascaded centrifuge plant for the purpose of enriching uranium 235. Such a cascade includes multiple gas separation stage each of which consists of a plurality of centrifuges. The product gas usually includes a large amount of He gas, and a cold trap is used to eliminate the He from UF 6 . The cold trap is operated periodically in such a way that the mixed gas of He and UF 6 is cooled to solidify only UF 6 and then warmed to obtain UF 6 by gasification. In order to operate the plant continuously, parallel multiple cold traps are operated alternatively. The operating conditions in such a complex cascade system are difficult to alter by conventional control methods. The present invention provides a rapid method of controlling the system when a certain percentage of the centrifuges in one stage malfunction. The control system consists of timers which are provided one for each cold trap to control the operational period of the trap. For example, if 20% of the centrifuges in a particular stage malfunction, the timer period of the cold traps attached to the normally operating centrifuge within the stage is maintained, and the period of all the other centrifuges are changed to 10/8 times that of the initial value. In this way the flow volume through all centrifuges except that in the particular stage is reduced to 80% of the initial value and the operation of the system can be continued with reduced efficiency. (Masui, R.)

  1. Method and apparatus for rapid adjustment of process gas inventory in gaseous diffusion cascades

    International Nuclear Information System (INIS)

    Dyer, R.H.; Fowler, A.H.; Vanstrum, P.R.

    1977-01-01

    The invention relates to an improved method and system for making relatively large and rapid adjustments in the process gas inventory of an electrically powered gaseous diffusion cascade in order to accommodate scheduled changes in the electrical power available for cascade operation. In the preferred form of the invention, the cascade is readied for a decrease in electrical input by simultaneously withdrawing substreams of the cascade B stream into respective process-gas-freezing and storage zones while decreasing the datum-pressure inputs to the positioning systems for the cascade control valves in proportion to the weight of process gas so removed. Consequently, the control valve positions are substantially unchanged by the reduction in invention, and there is minimal disturbance of the cascade isotopic gradient. The cascade is readied for restoration of the power cut by simultaneously evaporating the solids in the freezing zones to regenerate the process gas substreams and introducing them to the cascade A stream while increasing the aforementioned datum pressure inputs in proportion to the weight of process gas so returned. In the preferred form of the system for accomplishing these operations, heat exchangers are provided for freezing, storing, and evaporating the various substreams. Preferably, the heat exchangers are connected to use existing cascade auxiliary systems as a heat sink. A common control is employed to adjust and coordinate the necessary process gas transfers and datum pressure adjustments

  2. The Cascade of Non-Stationarity

    Science.gov (United States)

    Belmont, P.; Kumarasamy, K.; Kelly, S. A.; Schaffrath, K. R.; Beach, T. J.

    2014-12-01

    Landscapes and channel networks are dynamic systems, often characterized by immense variability in time and space. Systematic shifts in hydrologic, geomorphic, or ecologic drivers can cause a cascade of changes within the system, which may fundamentally alter the way the system itself functions. Due to variability in resilience and resisting forces throughout the landscape, this cascade of changes may manifest in different ways within any given system. Humans may also exert considerable influence, often amplifying or damping system response. We illustrate the cascading effects of non-stationary hydrology and geomorphology in the Minnesota River Basin (MRB), a 44,000 km2 natural laboratory in which pervasive landscape disturbance has been triggered by several well-documented events. Rapid base-level lowering 13,400 YBP along the mainstem Minnesota River created a wave of incision, which continues to propagate up tributary channel networks. Temperature and precipitation have changed significantly in the MRB over the past century with rising temperatures, shifting precipitation patterns and an increase in heavy rainfall events. Streamflow has changed drastically and variably throughout the basin with 5% exceedance flows increasing 60-100% in recent decades, as increases in precipitation have been amplified by land management and artificial drainage. Increases in channel width and depth have occurred variably in the mainstem Minnesota River, the actively incising lower (knick zone) reaches of tributaries, and the low gradient, passively meandering reaches above the knick zones. Altered hydrologic regimes and channel morphologies, combined with increased sedimentation and nutrient loading have adversely affected aquatic biota via disruption of life cycles and habitat degradation. Existing landscape, water quality, and flood risk models are poorly equipped to deal with the cascading effects of non-stationarity and therefore may grossly over- or under

  3. Prognostic Analysis System and Methods of Operation

    Science.gov (United States)

    MacKey, Ryan M. E. (Inventor); Sneddon, Robert (Inventor)

    2014-01-01

    A prognostic analysis system and methods of operating the system are provided. In particular, a prognostic analysis system for the analysis of physical system health applicable to mechanical, electrical, chemical and optical systems and methods of operating the system are described herein.

  4. Multiplicity distributions in QCD cascades

    International Nuclear Information System (INIS)

    Gustafson, G.

    1992-03-01

    Multiplicity distributions for hadrons and for jets are studied in QCD parton cascades. The colour dipole formalism is used and earlier results in the double log approximation are generalized to include terms which are suppressed by colour factors or factors of ln s. The result is a set of coupled differential equations, together with appropriate boundary conditions

  5. Azobenzene-functionalized cascade molecules

    DEFF Research Database (Denmark)

    Archut, A.; Vogtle, F.; De Cola, L.

    1998-01-01

    Cascade molecules bearing up to 32 azobenzene groups in the periphery have been prepared from poly(propylene imine) dendrimers and N-hydroxysuccinimide esters. The dendritic azobenzene species show similar isomerization properties as the corresponding azobenzene monomers. The all-E azobenzene...

  6. CASCADE: Introducing AI into CBT.

    Science.gov (United States)

    Hendley, R. J.; Jurascheck, N.

    1992-01-01

    Discusses changes in training requirements of commerce and industry in the United Kingdom and describes a project, CASCADE, that was developed to investigate and implement the introduction of artificial intelligence (AI) techniques into computer-based training (CBT). An overview of pilot projects in higher education settings is provided. (eight…

  7. Atom localization with double-cascade configuration

    Science.gov (United States)

    Gordeev, Maksim Yu; Efremova, Ekaterina A.; Rozhdestvensky, Yuri V.

    2016-03-01

    We investigate the one-dimensional (1D) and two-dimensional (2D) atom localization of a four-level system in a double-cascade configuration. We demonstrate the possibility of 1D localization in the field of a standing wave, 2D localization in the field of two standing waves and 2D localization only in the field of running waves by using different configurations of driven waves on transitions. In addition, for each configuration we reached a high-precision atom localization in one of the states at scales much smaller than the wavelength of the incident optical radiation.

  8. Multiheterodyne spectroscopy using interband cascade lasers

    Science.gov (United States)

    Sterczewski, Lukasz A.; Westberg, Jonas; Patrick, Charles Link; Kim, Chul Soo; Kim, Mijin; Canedy, Chadwick L.; Bewley, William W.; Merritt, Charles D.; Vurgaftman, Igor; Meyer, Jerry R.; Wysocki, Gerard

    2018-01-01

    While midinfrared radiation can be used to identify and quantify numerous chemical species, contemporary broadband midinfrared spectroscopic systems are often hindered by large footprints, moving parts, and high power consumption. In this work, we demonstrate multiheterodyne spectroscopy (MHS) using interband cascade lasers, which combines broadband spectral coverage with high spectral resolution and energy-efficient operation. The lasers generate up to 30 mW of continuous-wave optical power while consuming portable and high-resolution solid-state spectroscopic chemical sensors operating in the midinfrared.

  9. Atom localization with double-cascade configuration

    International Nuclear Information System (INIS)

    Gordeev, Maksim Yu; Rozhdestvensky, Yuri V; Efremova, Ekaterina A

    2016-01-01

    We investigate the one-dimensional (1D) and two-dimensional (2D) atom localization of a four-level system in a double-cascade configuration. We demonstrate the possibility of 1D localization in the field of a standing wave, 2D localization in the field of two standing waves and 2D localization only in the field of running waves by using different configurations of driven waves on transitions. In addition, for each configuration we reached a high-precision atom localization in one of the states at scales much smaller than the wavelength of the incident optical radiation. (paper)

  10. Long-term scheduling of large cascade hydropower stations in Jinsha River, China

    International Nuclear Information System (INIS)

    Wang, Chao; Zhou, Jianzhong; Lu, Peng; Yuan, Liu

    2015-01-01

    Highlights: • Proposing a Gaussian group selection strategy to overcome premature convergence. • Multi-population ant are developed to enhance the search ability. • Proposing a circulatory solution correction to handle constraints. • Numerical and real hydropower system simulation are used to verify its performance. • Compensation analysis has been done to large hydropower stations in Jinsha River. - Abstract: The Jinsha River is the third longest river in the world. It consists of four large hydropower stations with total installed capacity 42,960 MW lying on the upper stretches of the Yangtze River, which is the longest river in the word. Due to the great potential of large cascade hydropower stations on power generation, long-term scheduling of large cascade hydropower stations (LSLCHS) plays an important role in electrical power system. As more and more concentrations focused on the optimal operation of large cascade hydropower stations, the LSLCHS has been taken into a multi-dimensional, non-convex and non-linear optimization problem due to its complicated hydraulic connection relationships and varieties of complex constraints with considering its power generation, shipping and ecological characteristics. In order to solve this problem, a multi-population ant colony optimization for continuous domain (MACO R ) is proposed in this paper. A Gaussian group selection strategy is applied to overcome premature convergence and ants with different characteristics are employed to enhance search ability, and circulatory solution correction strategy is presented to handle outflow, water level and output constraints. Furthermore, the efficiency and stability of MACO R are verified by its more desirable results in comparison to other latest works in numerical simulation, and it can be a viable alternative for solving those complicated optimal problems. With the applications in hydropower operation, LSLCHS can obtain more power generation benefit than other

  11. A Human Body Analysis System

    Directory of Open Access Journals (Sweden)

    Girondel Vincent

    2006-01-01

    Full Text Available This paper describes a system for human body analysis (segmentation, tracking, face/hands localisation, posture recognition from a single view that is fast and completely automatic. The system first extracts low-level data and uses part of the data for high-level interpretation. It can detect and track several persons even if they merge or are completely occluded by another person from the camera's point of view. For the high-level interpretation step, static posture recognition is performed using a belief theory-based classifier. The belief theory is considered here as a new approach for performing posture recognition and classification using imprecise and/or conflicting data. Four different static postures are considered: standing, sitting, squatting, and lying. The aim of this paper is to give a global view and an evaluation of the performances of the entire system and to describe in detail each of its processing steps, whereas our previous publications focused on a single part of the system. The efficiency and the limits of the system have been highlighted on a database of more than fifty video sequences where a dozen different individuals appear. This system allows real-time processing and aims at monitoring elderly people in video surveillance applications or at the mixing of real and virtual worlds in ambient intelligence systems.

  12. Numerical Analysis on Effects of Positioning and Height of the Contoured Endwall on the Three-Dimensional Flow in an Annular Turbine Nozzle Guide Vane Cascade

    International Nuclear Information System (INIS)

    Lee, Wu Sang; Kim, Dae Hyun; Min, Jae Hong; Chung Jin Taek

    2007-01-01

    Endwall losses contribute significantly to the overall losses in modern turbomachinery, especially when aerodynamic airfoil load and pressure ratio are increased. Hence, reducing the extend and intensity of the secondary flow structures helps to enhance overall efficiency. From the large range of viable approaches, a promising combination positioning and height of endwall contouring was chosen. The objective of this study is to document the three-dimensional flow in a turbine cascade in terms of streamwise vorticity, total pressure loss distribution and static pressure distribution on the endwall and blade surface and to propose an appropriate positioning and height of the endwall contouring which show best secondary, overall loss reduction among the simulated endwall. The flow through the gas turbine were numerically analyzed using three dimensional Navier-Stroke equations with a commercial CFD code ANSYS CFX-10. The result shows that the overall loss is reduced near the flat endwall rather than contoured endwall, and the case of contoured endwall installed at 30% from leading edge with height of 25% for span showed best performance

  13. Cascaded Bragg scattering in fiber optics.

    Science.gov (United States)

    Xu, Y Q; Erkintalo, M; Genty, G; Murdoch, S G

    2013-01-15

    We report on a theoretical and experimental study of cascaded Bragg scattering in fiber optics. We show that the usual energy-momentum conservation of Bragg scattering can be considerably relaxed via cascade-induced phase-matching. Experimentally we demonstrate frequency translation over six- and 11-fold cascades, in excellent agreement with derived phase-matching conditions.

  14. Multicomponent isotope separation in matched abundance ratio cascades composed of stages with large separation factors

    International Nuclear Information System (INIS)

    Von Halle, E.

    1987-06-01

    The concept of the matched abundance ratio cascade and the system of equations for performing multicomponent productivity calculations upon them has proven extremely useful for analyzing the behavior of gaseous diffusion plants in which the stage separation factors are very nearly equal to unity. Recent interest in the gas centrifuge process, in which the separation factor of a single centrifuge can be relatively large, makes desirable the extension of the theory of the matched abundance ratio cascade to cascades composed of stages with large separation factors. Equations permit the calculation of the productivity for simple cascades composed of stages with large separation factors. The concentration gradient of each of the isotopic species present can be calculated and the cascade description can be determined. An illustrative example dealing with the separation of the isotopes of tungsten in a cascade composed of gas centrifuges is included

  15. A Power System Network Splitting Strategy Based on Contingency Analysis

    Directory of Open Access Journals (Sweden)

    Nur Zawani Saharuddin

    2018-02-01

    Full Text Available This paper proposes a network splitting strategy following critical line outages based on N-1 contingency analysis. Network splitting is the best option for certain critical outages when the tendency of severe cascading failures is very high. Network splitting is executed by splitting the power system network into feasible set of islands. Thus, it is essential to identify the optimal splitting solution (in terms of minimal power flow disruption that satisfies certain constraints. This paper determines the optimal splitting solution for each of the critical line outage using discrete evolutionary programming (DEP optimization technique assisted by heuristic initialization approach. Heuristic initialization provides the best initial cutsets which will guide the optimization technique to find the optimal splitting solution. Generation–load balance and transmission line overloading analysis are carried out in each island to ensure the steady state stability is achieved. Load shedding scheme is initiated if the power balance criterion is violated in any island to sustain the generation–load balance. The proposed technique is validated on the IEEE 118 bus system. Results show that the proposed approach produces an optimal splitting solution with lower power flow disruption during network splitting execution.

  16. Wavefront measurement of single-mode quantum cascade laser beam for seed application in laser-produced plasma extreme ultraviolet system.

    Science.gov (United States)

    Nowak, Krzysztof M; Ohta, Takeshi; Suganuma, Takashi; Yokotsuka, Toshio; Fujimoto, Junichi; Mizoguchi, Hakaru

    2012-12-01

    Quantum cascade laser (QCL) is a very attractive seed source for a multikilowatt pulsed CO2 lasers applied for driving extreme ultraviolet emitting plasmas. In this Letter, we investigate output beam properties of a QCL designed to address P18 and P20 lines of 10.6 micron band of CO2 molecule. In particular, output beam quality and stability are investigated for the first time. A well-defined linear polarization and a single-mode operation enabled a use of phase retrieval method for full description of QCL output beam. A direct, multi-image numerical phase retrieval technique was developed and successfully applied to the measured intensity patterns of a QCL beam. Very good agreement between the measured and reconstructed beam profiles was observed at distances ranging from QCL aperture to infinity, proving a good understanding of the beam propagation. The results also confirm a high spatial coherence and high stability of the beam parameters, the features expected from an excellent seed source.

  17. Effect of field quantization on Rabi oscillation of equidistant cascade ...

    Indian Academy of Sciences (India)

    We have exactly solved a model of equidistant cascade four-level system interacting with a single-mode radiation field both semiclassically and quantum mechanically by exploiting its similarity with Jaynes-Cummings model. For the classical field, it is shown that the Rabi oscillation of the system initially in the first level ...

  18. Comment on “Short-term combined economic emission scheduling of hydrothermal power systems with cascaded reservoirs using differential evolution” by K.K. Mandal and N. Chakaborty [Energy Convers. Manage. 50 (2009) 97–104

    International Nuclear Information System (INIS)

    Ahmadi, Abdollah; Nezhad, Ali Esmaeel

    2015-01-01

    This paper discusses the short-term combined economic emission scheduling of hydrothermal power systems with cascaded reservoirs [Energy Convers Manage. 50 (2009) 97–104], while differential evolution algorithm has been employed to solve the optimization problem. However, this problem is subjected to several constraints like the generation limitations of generating units. The solutions reported in the original paper do not satisfy the constraint on the initial and final reservoir storage volumes of hydro units as well as the constraint on the generated power by such units, which should be positive at any time of the scheduling period. Thus, this paper intends to prove this issue and solve the problem using Normal Boundary Intersection (NBI) method, in order to propose the correct solutions satisfying all the constraints of the short-term hydrothermal scheduling problem

  19. Systems analysis department annual progress report 1986

    International Nuclear Information System (INIS)

    Grohnheit, P.E.; Larsen, H.; Vestergaard, N.K.

    1987-02-01

    The report describes the work of the Systems Analysis Department at Risoe National Laboratory during 1986. The activities may be classified as energy systems analysis and risk and reliability analysis. The report includes a list of staff members. (author)

  20. Film analysis systems and applications

    Energy Technology Data Exchange (ETDEWEB)

    Yonekura, Y.; Brill, A.B.

    1981-01-01

    The different components that can be used in modern film analysis systems are reviewed. TV camera and charge-coupled device sensors coupled to computers provide low cost systems for applications such as those described. The autoradiography (ARG) method provides an important tool for medical research and is especially useful for the development of new radiopharmaceutical compounds. Biodistribution information is needed for estimation of radiation dose, and for interpretation of the significance of observed patterns. The need for such precise information is heightened when one seeks to elucidate physiological principles/factors in normal and experimental models of disease. The poor spatial resolution achieved with current PET-imaging systems limits the information on radioreceptor mapping, neutrotransmitter, and neuroleptic drug distribution that can be achieved from patient studies. The artful use of ARG in carefully-controlled animal studies will be required to provide the additional information needed to fully understand results obtained with this new important research tool. (ERB)

  1. Film analysis systems and applications

    International Nuclear Information System (INIS)

    Yonekura, Y.; Brill, A.B.

    1981-01-01

    The different components that can be used in modern film analysis systems are reviewed. TV camera and charge-coupled device sensors coupled to computers provide low cost systems for applications such as those described. The autoradiography (ARG) method provides an important tool for medical research and is especially useful for the development of new radiopharmaceutical compounds. Biodistribution information is needed for estimation of radiation dose, and for interpretation of the significance of observed patterns. The need for such precise information is heightened when one seeks to elucidate physiological principles/factors in normal and experimental models of disease. The poor spatial resolution achieved with current PET-imaging systems limits the information on radioreceptor mapping, neutrotransmitter, and neuroleptic drug distribution that can be achieved from patient studies. The artful use of ARG in carefully-controlled animal studies will be required to provide the additional information needed to fully understand results obtained with this new important research tool

  2. Calibration of PIXE-SP system of elementary analysis

    International Nuclear Information System (INIS)

    Tabacniks, M.H.

    1983-04-01

    The set-up and calibration of the PIXE-SP System of Elementary Analysis located at the Institute of Physics of the University of Sao Paulo is described. The PIXE-SP, that operates with 8 MeV alpha beam, has been calibrated for elements with Z >= 11, by means of homemade evaporated standard targets of Al, Si, Bacl 2 , K 2 CrO 4 , Ti, Cr, Mn, Fe, Cu, Ge, Ag, Sn, and Au. Those targets are thin, homogeneous, and have been calbrated on a microbalance within an average precision of 6%. The overall precision of the PIXE-SP System is estimated in 10% for elements with 16 2 thick, irradiated with a 10 μC electric charge, shows a minimum of about 0,1 ng (approximated 4 ppm) for Mn. The PIXE-SP System has also been intercalibrated with the PIXE located at University of Gent, Belgium, by means of 12 atmospheric aerosol targets collected on two Batelle Cascade Impactors. The analyzed masses of elements with 16 [pt

  3. Automation for System Safety Analysis

    Science.gov (United States)

    Malin, Jane T.; Fleming, Land; Throop, David; Thronesbery, Carroll; Flores, Joshua; Bennett, Ted; Wennberg, Paul

    2009-01-01

    This presentation describes work to integrate a set of tools to support early model-based analysis of failures and hazards due to system-software interactions. The tools perform and assist analysts in the following tasks: 1) extract model parts from text for architecture and safety/hazard models; 2) combine the parts with library information to develop the models for visualization and analysis; 3) perform graph analysis and simulation to identify and evaluate possible paths from hazard sources to vulnerable entities and functions, in nominal and anomalous system-software configurations and scenarios; and 4) identify resulting candidate scenarios for software integration testing. There has been significant technical progress in model extraction from Orion program text sources, architecture model derivation (components and connections) and documentation of extraction sources. Models have been derived from Internal Interface Requirements Documents (IIRDs) and FMEA documents. Linguistic text processing is used to extract model parts and relationships, and the Aerospace Ontology also aids automated model development from the extracted information. Visualizations of these models assist analysts in requirements overview and in checking consistency and completeness.

  4. Symmetries and stochastic symmetry breaking in multifractal geophysics: analysis and simulation with the help of the Lévy-Clifford algebra of cascade generators..

    Science.gov (United States)

    Schertzer, D. J. M.; Tchiguirinskaia, I.

    2016-12-01

    Multifractal fields, whose definition is rather independent of their domain dimension, have opened a new approach of geophysics enabling to explore its spatial extension that is of prime importance as underlined by the expression "spatial chaos". However multifractals have been until recently restricted to be scalar valued, i.e. to one-dimensional codomains. This has prevented to deal with the key question of complex component interactions and their non trivial symmetries. We first emphasize that the Lie algebra of stochastic generators of cascade processes enables us to generalize multifractals to arbitrarily large codomains, e.g. flows of vector fields on large dimensional manifolds. In particular, we have recently investigated the neat example of stable Levy generators on Clifford algebra that have a number of seductive properties, e.g. universal statistical and robust algebra properties, both defining the basic symmetries of the corresponding fields (Schertzer and Tchiguirinskaia, 2015). These properties provide a convenient multifractal framework to study both the symmetries of the fields and how they stochastically break the symmetries of the underlying equations due to boundary conditions, large scale rotations and forcings. These developments should help us to answer to challenging questions such as the climatology of (exo-) planets based on first principles (Pierrehumbert, 2013), to fully address the question of the limitations of quasi- geostrophic turbulence (Schertzer et al., 2012) and to explore the peculiar phenomenology of turbulent dynamics of the atmosphere or oceans that is neither two- or three-dimensional. Pierrehumbert, R.T., 2013. Strange news from other stars. Nature Geoscience, 6(2), pp.8183. Schertzer, D. et al., 2012. Quasi-geostrophic turbulence and generalized scale invariance, a theoretical reply. Atmos. Chem. Phys., 12, pp.327336. Schertzer, D. & Tchiguirinskaia, I., 2015. Multifractal vector fields and stochastic Clifford algebra

  5. Deciphering complex dynamics of water counteraction around secondary structural elements of allosteric protein complex: Case study of SAP-SLAM system in signal transduction cascade

    Science.gov (United States)

    Samanta, Sudipta; Mukherjee, Sanchita

    2018-01-01

    The first hydration shell of a protein exhibits heterogeneous behavior owing to several attributes, majorly local polarity and structural flexibility as revealed by solvation dynamics of secondary structural elements. We attempt to recognize the change in complex water counteraction generated due to substantial alteration in flexibility during protein complex formation. The investigation is carried out with the signaling lymphocytic activation molecule (SLAM) family of receptors, expressed by an array of immune cells, and interacting with SLAM-associated protein (SAP), composed of one SH2 domain. All atom molecular dynamics simulations are employed to the aqueous solutions of free SAP and SLAM-peptide bound SAP. We observed that water dynamics around different secondary structural elements became highly affected as well as nicely correlated with the SLAM-peptide induced change in structural rigidity obtained by thermodynamic quantification. A few instances of contradictory dynamic features of water to the change in structural flexibility are explained by means of occluded polar residues by the peptide. For βD, EFloop, and BGloop, both structural flexibility and solvent accessibility of the residues confirm the obvious contribution. Most importantly, we have quantified enhanced restriction in water dynamics around the second Fyn-binding site of the SAP due to SAP-SLAM complexation, even prior to the presence of Fyn. This observation leads to a novel argument that SLAM induced more restricted water molecules could offer more water entropic contribution during the subsequent Fyn binding and provide enhanced stability to the SAP-Fyn complex in the signaling cascade. Finally, SLAM induced water counteraction around the second binding site of the SAP sheds light on the allosteric property of the SAP, which becomes an integral part of the underlying signal transduction mechanism.

  6. Deciphering complex dynamics of water counteraction around secondary structural elements of allosteric protein complex: Case study of SAP-SLAM system in signal transduction cascade.

    Science.gov (United States)

    Samanta, Sudipta; Mukherjee, Sanchita

    2018-01-28

    The first hydration shell of a protein exhibits heterogeneous behavior owing to several attributes, majorly local polarity and structural flexibility as revealed by solvation dynamics of secondary structural elements. We attempt to recognize the change in complex water counteraction generated due to substantial alteration in flexibility during protein complex formation. The investigation is carried out with the signaling lymphocytic activation molecule (SLAM) family of receptors, expressed by an array of immune cells, and interacting with SLAM-associated protein (SAP), composed of one SH2 domain. All atom molecular dynamics simulations are employed to the aqueous solutions of free SAP and SLAM-peptide bound SAP. We observed that water dynamics around different secondary structural elements became highly affected as well as nicely correlated with the SLAM-peptide induced change in structural rigidity obtained by thermodynamic quantification. A few instances of contradictory dynamic features of water to the change in structural flexibility are explained by means of occluded polar residues by the peptide. For βD, EFloop, and BGloop, both structural flexibility and solvent accessibility of the residues confirm the obvious contribution. Most importantly, we have quantified enhanced restriction in water dynamics around the second Fyn-binding site of the SAP due to SAP-SLAM complexation, even prior to the presence of Fyn. This observation leads to a novel argument that SLAM induced more restricted water molecules could offer more water entropic contribution during the subsequent Fyn binding and provide enhanced stability to the SAP-Fyn complex in the signaling cascade. Finally, SLAM induced water counteraction around the second binding site of the SAP sheds light on the allosteric property of the SAP, which becomes an integral part of the underlying signal transduction mechanism.

  7. On the trajectories of CRL...LR...R orbits, their period-doubling cascades and saddle-node bifurcation cascades

    International Nuclear Information System (INIS)

    Cerrada, Lucia; San Martin, Jesus

    2011-01-01

    In this Letter, it is shown that from a two region partition of the phase space of a one-dimensional dynamical system, a p-region partition can be obtained for the CRL...LR...R orbits. That is, permutations associated with symbolic sequences are obtained. As a consequence, the trajectory in phase space is directly deduced from permutation. From this permutation other permutations associated with period-doubling and saddle-node bifurcation cascades are derived, as well as other composite permutations. - Research highlights: → Symbolic sequences are the usual topological approach to dynamical systems. → Permutations bear more physical information than symbolic sequences. → Period-doubling cascade permutations associated with original sequences are obtained. → Saddle-node cascade permutations associated with original sequences are obtained. → Composite permutations are derived.

  8. Atom-atom collision cascades localization

    International Nuclear Information System (INIS)

    Kirsanov, V.V.

    1980-01-01

    The presence of an impurity and thermal vibration influence on the atom-atom collision cascade development is analysed by the computer simulation method (the modificated dynamic model). It is discovered that the relatively low energetic cascades are localized with the temperature increase of an irradiated crystal. On the basis of the given effect the mechanism of splitting of the high energetic cascades into subcascades is proposed. It accounts for two factors: the primary knocked atom energy and the irradiated crystal temperature. Introduction of an impurity also localizes the cascades independently from the impurity atom mass. The cascades localization leads to intensification of the process of annealing in the cascades and reduction of the post-cascade vacancy cluster sizes. (author)

  9. The ATLAS distributed analysis system

    International Nuclear Information System (INIS)

    Legger, F

    2014-01-01

    In the LHC operations era, analysis of the multi-petabyte ATLAS data sample by globally distributed physicists is a challenging task. To attain the required scale the ATLAS Computing Model was designed around the concept of Grid computing, realized in the Worldwide LHC Computing Grid (WLCG), the largest distributed computational resource existing in the sciences. The ATLAS experiment currently stores over 140 PB of data and runs about 140,000 concurrent jobs continuously at WLCG sites. During the first run of the LHC, the ATLAS Distributed Analysis (DA) service has operated stably and scaled as planned. More than 1600 users submitted jobs in 2012, with 2 million or more analysis jobs per week, peaking at about a million jobs per day. The system dynamically distributes popular data to expedite processing and maximally utilize resources. The reliability of the DA service is high and steadily improving; Grid sites are continually validated against a set of standard tests, and a dedicated team of expert shifters provides user support and communicates user problems to the sites. Both the user support techniques and the direct feedback of users have been effective in improving the success rate and user experience when utilizing the distributed computing environment. In this contribution a description of the main components, activities and achievements of ATLAS distributed analysis is given. Several future improvements being undertaken will be described.

  10. The ATLAS distributed analysis system

    Science.gov (United States)

    Legger, F.; Atlas Collaboration

    2014-06-01

    In the LHC operations era, analysis of the multi-petabyte ATLAS data sample by globally distributed physicists is a challenging task. To attain the required scale the ATLAS Computing Model was designed around the concept of Grid computing, realized in the Worldwide LHC Computing Grid (WLCG), the largest distributed computational resource existing in the sciences. The ATLAS experiment currently stores over 140 PB of data and runs about 140,000 concurrent jobs continuously at WLCG sites. During the first run of the LHC, the ATLAS Distributed Analysis (DA) service has operated stably and scaled as planned. More than 1600 users submitted jobs in 2012, with 2 million or more analysis jobs per week, peaking at about a million jobs per day. The system dynamically distributes popular data to expedite processing and maximally utilize resources. The reliability of the DA service is high and steadily improving; Grid sites are continually validated against a set of standard tests, and a dedicated team of expert shifters provides user support and communicates user problems to the sites. Both the user support techniques and the direct feedback of users have been effective in improving the success rate and user experience when utilizing the distributed computing environment. In this contribution a description of the main components, activities and achievements of ATLAS distributed analysis is given. Several future improvements being undertaken will be described.

  11. Stability analysis of nonlinear systems

    CERN Document Server

    Lakshmikantham, Vangipuram; Martynyuk, Anatoly A

    2015-01-01

    The book investigates stability theory in terms of two different measure, exhibiting the advantage of employing families of Lyapunov functions and treats the theory of a variety of inequalities, clearly bringing out the underlying theme. It also demonstrates manifestations of the general Lyapunov method, showing how this technique can be adapted to various apparently diverse nonlinear problems. Furthermore it discusses the application of theoretical results to several different models chosen from real world phenomena, furnishing data that is particularly relevant for practitioners. Stability Analysis of Nonlinear Systems is an invaluable single-sourse reference for industrial and applied mathematicians, statisticians, engineers, researchers in the applied sciences, and graduate students studying differential equations.

  12. MOLECULAR DYNAMICS SIMULATIONS OF DISPLACEMENT CASCADES IN MOLYBDENUM

    International Nuclear Information System (INIS)

    Smith, Richard Whiting

    2003-01-01

    Molecular dynamics calculations have been employed to simulate displacement cascades in neutron irradiated Mo. A total of 90 simulations were conducted for PKA energies between 1 and 40 keV and temperatures from 298 to 923K. The results suggest very little effect of temperature on final defect count and configuration, but do display a temperature effect on peak defect generation prior to cascade collapse. Cascade efficiency, relative to the NRT model, is computed to lie between 1/4 and 1/3 in agreement with simulations performed on previous systems. There is a tendency for both interstitials and vacancies to cluster together following cascade collapse producing vacancy rich regions surrounded by interstitials. Although coming to rest in close proximity, the point defects comprising the clusters generally do not lie within the nearest neighbor positions of one another, except for the formation of dumbbell di-interstitials. Cascades produced at higher PKA energies (20 or 40 keV) exhibit the formation of subcascades

  13. The Utrecht 850 kV cascade generator I. Beam deflection and energy control

    NARCIS (Netherlands)

    Braams, C.M.; Smith, P.B.

    The beam deflection magnet and energy control system of the Utrecht cascade generator are described. The uniform-field magnet has entrance and exit slits located outside the magnetic held. Since the cascade generator produces a vertical beam, the most convenient choice for the angle of deflection

  14. A topological investigation of phase transitions of cascading failures in power grids

    NARCIS (Netherlands)

    Koç, Y.; Warnier, M.; Mieghem, P. van; Kooij, R.E.; Brazier, F.M.T.

    2014-01-01

    Cascading failures are one of the main reasons for blackouts in electric power transmission grids. The economic cost of such failures is in the order of tens of billion dollars annually. The loading level of power system is a key aspect to determine the amount of the damage caused by cascading

  15. Outage Analysis of Asymmetric RF-FSO Systems

    KAUST Repository

    Ansari, Imran Shafique

    2017-03-20

    In this work, the outage performance analysis of a dual-hop transmission system composed of asymmetric radio frequency (RF) channels cascaded with free-space optical (FSO) links is presented. The RF links are modeled by the Rayleigh fading distribution and the FSO links are modeled by Malaga (M) turbulence distribution. The FSO links account for pointing errors and both types of detection techniques (i.e. heterodyne detection as well as intensity modulation/direct detection (IM/DD)). Transmit diversity is applied at the source, selection combining is applied at the destination, and the relay is equipped with single RF receive antenna and single aperture for relaying the information over FSO links. With this model, a new exact closed-form expression is derived for the outage probability of the end-to- end signal-to-noise ratio of such communication systems in terms of the Meijer\\'s G function under fixed amplify-and-forward relay scheme. All new analytical results are verified via computer-based Monte-Carlo simulations and are illustrated by some selected numerical results.

  16. Bearing-Only Formation Control for Cascade Multirobots

    Directory of Open Access Journals (Sweden)

    Qing Han

    2016-01-01

    Full Text Available A new formation control method is proposed, which is used to queue multirobots in a single-direction cascade structure. In the cascade formation, each robot is a follower for the previous robot and a leader for the next robot, and the robots in the middle act as both leader and follower. The follower robot can only observe the bearing information of the leader robot. The observability of the cascade leader-follower formation is studied, which shows that the bearing-only observation meets the observability conditions required for the nonlinear system. Based on the bearing-only observations, the unscented Kalman filter (UKF is employed for the state estimation of the leader and the follower robots at all levels, which enables the real-time movement control of the follower robots via the input-output feedback control. Simulation results demonstrate that the proposed approach can efficiently control the formation of multirobots as desired.

  17. Cascade: a review of heat transport and plant design issues

    International Nuclear Information System (INIS)

    Murray, K.A.; McDowell, M.W.

    1984-01-01

    A conceptual heat transfer loop for Cascade, a centrifugal-action solid-breeder reaction chamber, has been investigated and results are presented. The Cascade concept, a double-cone-shaped reaction chamber, rotates along its horizontal axis. Solid Li 2 O or other lithium-ceramic granules are injected tangentially through each end of the chamber. The granules cascade axially from the smaller radii at the ends to the larger radius at the center, where they are ejected into a stationary granule catcher. Heat and tritium are then removed from the granules and the granules are reinjected into the chamber. A 50% dense Li 2 O granule throughput of 2.8 m 3 /s is transferred from the reaction chamber to the steam generators via continuous bucket elevators. The granules then fall by gravity through 4 vertical steam generators. The entire transport system is maintained at the same vacuum conditions present inside the reaction chamber

  18. The ATLAS Distributed Analysis System

    CERN Document Server

    Legger, F; The ATLAS collaboration; Pacheco Pages, A; Stradling, A

    2013-01-01

    In the LHC operations era, analysis of the multi-petabyte ATLAS data sample by globally distributed physicists is a challenging task. To attain the required scale the ATLAS Computing Model was designed around the concept of grid computing, realized in the Worldwide LHC Computing Grid (WLCG), the largest distributed computational resource existing in the sciences. The ATLAS experiment currently stores over 140 PB of data and runs about 140,000 concurrent jobs continuously at WLCG sites. During the first run of the LHC, the ATLAS Distributed Analysis (DA) service has operated stably and scaled as planned. More than 1600 users submitted jobs in 2012, with 2 million or more analysis jobs per week, peaking at about a million jobs per day. The system dynamically distributes popular data to expedite processing and maximally utilize resources. The reliability of the DA service is high but steadily improving; grid sites are continually validated against a set of standard tests, and a dedicated team of expert shifters ...

  19. The ATLAS Distributed Analysis System

    CERN Document Server

    Legger, F; The ATLAS collaboration

    2014-01-01

    In the LHC operations era, analysis of the multi-petabyte ATLAS data sample by globally distributed physicists is a challenging task. To attain the required scale the ATLAS Computing Model was designed around the concept of grid computing, realized in the Worldwide LHC Computing Grid (WLCG), the largest distributed computational resource existing in the sciences. The ATLAS experiment currently stores over 140 PB of data and runs about 140,000 concurrent jobs continuously at WLCG sites. During the first run of the LHC, the ATLAS Distributed Analysis (DA) service has operated stably and scaled as planned. More than 1600 users submitted jobs in 2012, with 2 million or more analysis jobs per week, peaking at about a million jobs per day. The system dynamically distributes popular data to expedite processing and maximally utilize resources. The reliability of the DA service is high but steadily improving; grid sites are continually validated against a set of standard tests, and a dedicated team of expert shifters ...

  20. Optical Remote Sensing for Fence-Line Monitoring using Open-Path Quantum Cascade Laser (QCL) mono-static system for multiple target compounds in the Mid IR 7-13um (Fingerprint) region.

    Science.gov (United States)

    Zemek, P. G.

    2017-12-01

    Quantum Cascade Lasers (QCLs) are quickly replacing Tunable Diode Lasers (TDL) for multi-target species identification and quantification in both extractive and open-path (OP) Optical Remote Sensing (ORS) fence-line instrumentation. As was seen with TDL incorporation and pricing drops as the adoption by the telecommunications industry and its current scaling has improved robustness and pricing, the QCL is also, albiet more slowly, becoming a mature market. There are several advantages of QCLs over conventional TDLs such as improved brightness and beam density, high resolution, as well as the incorporation of external etalons or internal gratings to scan over wide spectral areas. QCLs typically operate in the Mid infra-red (MIR) as opposed to the Near-Infrared (NIR) region used with TDL. The MidIR is a target rich absorption band area where compounds have high absorbtivity coefficients resulting in better detection limits as compared to TDL instruments. The use of novel chemometrics and more sensitive non-cryo-cooled detectors has allowed some of the first QCL open-path instruments in both active and passive operation. Data and field studies of one of the newest QCL OP systems is presented that allows one system to measure multiple target compounds. Multiple QCL spectral regions may be stitched together to increase the capability of QCLs over TDL OP systems. A comparison of several ORS type systems will be presented.

  1. A system analysis of a suboptimal surgical experience

    Directory of Open Access Journals (Sweden)

    Richards Michael

    2009-01-01

    Full Text Available Abstract Background System analyses of incidents that occur in the process of health care delivery are rare. A case study of a series of incidents that one of the authors experienced after routine urologic surgery is presented. We interpret the sequence of events as a case of cascading incidents that resulted in outcomes that were suboptimal, although fortunately not fatal. Methods A system dynamics approach was employed to develop illustrative models (flow diagrams of the dynamics of the patient's interaction with surgery and emergency departments. The flow diagrams were constructed based upon the experience of the patient, chart review, discussion with the involved physicians as well as several physician colleagues, comparison of our diagrams with those developed by the hospital of interest for internal planning purposes, and an iterative process with one of the co-authors who is a system dynamics expert. A dynamic hypothesis was developed using insights gained by building the flow diagrams. Results The incidents originated in design flaws and many small innocuous system changes that have occurred incrementally over time, which by themselves may have no consequence but in conjunction with some system randomness can have serious consequences. In the patient's case, the incidents that occurred in preoperative assessment and surgery originated in communication and procedural failures. System delays, communication failures, and capacity issues contributed largely to the subsequent incidents. Some of these issues were controllable by the physicians and staff of the institution, whereas others were less controllable. To the system's credit, some of the more controllable issues were addressed, but systemic problems like overcrowding are unlikely to be addressed in the near future. Conclusion This is first instance that we are aware of in the literature where a system dynamics approach has been used to analyze a patient safety experience. The

  2. 'RECASS'. Radioecological analysis support system

    International Nuclear Information System (INIS)

    Shershakov, V.

    1998-01-01

    The RECASS is developed as a computer system designed for radiation monitoring and decision-making support in a nuclear emergency. The RECASS system has excellent capabilities for collecting, storing, and presenting data from the radiological situation of contaminated areas. It is well designed for modeling radionuclide migration in the environmental media and for assessing countermeasures in terms of doses received by population groups as a result of radioactive contamination. For RECASS to be used as a basis for solving the problems of radioecological analysis, it is essential that mapping facilities are provided and that scaling capabilities allow data to be presented with the necessary degree of detail and accuracy. Because of the on-line links with the operating network of radiological monitoring, RECASS is capable of collecting meteorological and radiological data from across the country and storing this information in its databases. The availability of data from the network of radiological monitoring makes it possible to develop RECASS as a real-time emergency response system. (R.P.)

  3. Experimental study on cascaded attitude angle control of a multi-rotor unmanned aerial vehicle with the simple internal model control method

    Energy Technology Data Exchange (ETDEWEB)

    Song, Jun Beom [Dept. of Aviation Maintenance, Dongwon Institute of Science and Technology, Yangsan (Korea, Republic of); Byun, Young Seop; Jeong, Jin Seok; Kim, Jeong; Kang, Beom Soo [Dept. of Aerospace Engineering, Pusan National University, Busan (Korea, Republic of)

    2016-11-15

    This paper proposes a cascaded control structure and a method of practical application for attitude control of a multi-rotor Unmanned aerial vehicle (UAV). The cascade control, which has tighter control capability than a single-loop control, is rarely used in attitude control of a multi-rotor UAV due to the input-output relation, which is no longer simply a set-point to Euler angle response transfer function of a single-loop PID control, but there are multiply measured signals and interactive control loops that increase the complexity of evaluation in conventional way of design. However, it is proposed in this research a method that can optimize a cascade control with a primary and secondary loops and a PID controller for each loop. An investigation of currently available PID-tuning methods lead to selection of the Simple internal model control (SIMC) method, which is based on the Internal model control (IMC) and direct-synthesis method. Through the analysis and experiments, this research proposes a systematic procedure to implement a cascaded attitude controller, which includes the flight test, system identification and SIMC-based PID-tuning. The proposed method was validated successfully from multiple applications where the application to roll axis lead to a PID-PID cascade control, but the application to yaw axis lead to that of PID-PI.

  4. Experimental study on cascaded attitude angle control of a multi-rotor unmanned aerial vehicle with the simple internal model control method

    International Nuclear Information System (INIS)

    Song, Jun Beom; Byun, Young Seop; Jeong, Jin Seok; Kim, Jeong; Kang, Beom Soo

    2016-01-01

    This paper proposes a cascaded control structure and a method of practical application for attitude control of a multi-rotor Unmanned aerial vehicle (UAV). The cascade control, which has tighter control capability than a single-loop control, is rarely used in attitude control of a multi-rotor UAV due to the input-output relation, which is no longer simply a set-point to Euler angle response transfer function of a single-loop PID control, but there are multiply measured signals and interactive control loops that increase the complexity of evaluation in conventional way of design. However, it is proposed in this research a method that can optimize a cascade control with a primary and secondary loops and a PID controller for each loop. An investigation of currently available PID-tuning methods lead to selection of the Simple internal model control (SIMC) method, which is based on the Internal model control (IMC) and direct-synthesis method. Through the analysis and experiments, this research proposes a systematic procedure to implement a cascaded attitude controller, which includes the flight test, system identification and SIMC-based PID-tuning. The proposed method was validated successfully from multiple applications where the application to roll axis lead to a PID-PID cascade control, but the application to yaw axis lead to that of PID-PI

  5. Strategic information is everyone's business: perspectives from an international stakeholder meeting to enhance strategic information data along the HIV Cascade for people who inject drugs.

    Science.gov (United States)

    Pierce, Richard D; Hegle, Jennifer; Sabin, Keith; Agustian, Edo; Johnston, Lisa G; Mills, Stephen; Todd, Catherine S

    2015-10-16

    People who inject drugs (PWID) are at increased HIV transmission risk because of unsafe injecting practices and a host of other individual, network, and structural factors. Thus, PWID have a great need for services within the Cascade of HIV prevention, diagnosis, care, and treatment (HIV Cascade). Yet the systems that monitor their progress through the Cascade are often lacking. Subsequently, fewer reliable data are available to guide programs targeting this key population (KP). Programmatic data, which are helpful in tracking PWID through the Cascade, also are limited because not all countries have harm reduction programming from which to estimate Cascade indicators. Also, due to stigma and the illegal nature of drug use, PWID may not disclose their drug use behavior or HIV status when accessing services. Consequently, PWID appear to have low HIV testing rates and, for those living with HIV, lower access to health services and lower viral suppression rates than do other KP groups. This commentary, based on outcomes from an international stakeholder meeting, identifies data gaps and proposes solutions to strengthen strategic information (SI), the systematic collection, analysis, and dissemination of information, to optimize HIV prevention, care, and treatment programming for PWID.

  6. Intensity correlations and anticorrelations in a three-level cascade ...

    Indian Academy of Sciences (India)

    2016-11-02

    Nov 2, 2016 ... absorption spectra and the corresponding intensity– intensity correlation function (using the convention of refs [8–12]) for the probe transition. 2. Formulation. We model the atom as a three-level system in cascade configuration. The atomic level scheme is shown in figure 1. The top level |3〉 (energy E3) ...

  7. Dynamic signaling cascades: reversible covalent reaction-coupled molecular switches.

    Science.gov (United States)

    Ren, Yulong; You, Lei

    2015-11-11

    The research of systems chemistry exploring complex mixtures of interacting synthetic molecules has been burgeoning recently. Herein we demonstrate for the first time the coupling of molecular switches with a dynamic covalent reaction (DCR) and the modulation of created chemical cascades with a variety of inputs, thus closely mimicking a biological signaling system. A novel Michael type DCR of 10-methylacridinium perchlorate and monothiols exhibiting excellent regioselectivity and tunable affinity was discovered. A delicate balance between the unique reactivity of the reactant and the stability of the adduct leads to the generation of a strong acid in a thermodynamically controlled system. The dynamic cascade was next created via coupling of the DCR and a protonation-induced configurational switch (E/Z isomerization) through a proton relay. Detailed examination of the interdependence of the equilibrium enabled us to rationally optimize the cascade and also shed light on the possible intermediate of the switching process. Furthermore, relative independence of the coupled reactions was verified by the identification of stimuli that are able to facilitate one reaction but suppress the other. To further enhance systematic complexity, a second DCR of electrophilic aldehydes and thiols was employed for the reversible inhibition of the binary system, thus achieving the interplay of multiple equilibria. Finally, a fluorescence switch was turned on through coupling with the DCR, showcasing the versatility of our strategy. The results described herein should pave the way for the exploitation of multifunctional dynamic covalent cascades.

  8. Effect of field quantization on Rabi oscillation of equidistant cascade ...

    Indian Academy of Sciences (India)

    unitary gates relevant for the quantum computation [41,42]. However, these treat- ments are not ... veloped a dressed atom approach of calculating the probabilities with all possible initial conditions especially in the ..... the Rabi oscillation for the equidistant cascade [44] and also for lambda and vee three-level systems [46].

  9. Economic impacts of bio-refinery and resource cascading systems: An applied general equilibrium analysis for Poland

    NARCIS (Netherlands)

    Ignaciuk, A.; Sanders, J.P.M.

    2007-01-01

    Due to more stringent energy and climate policies, it is expected that many traditional chemicals will be replaced by their biomass-based substitutes, bio-chemicals. These innovations, however, can influence land allocation since the demand for land dedicated to specific crops might increase.

  10. Analysis of the efficiency of a hybrid foil tunnel heating system

    Science.gov (United States)

    Kurpaska, Sławomir; Pedryc, Norbert

    2017-10-01

    The paper analyzes the efficiency of the hybrid system used to heat the foil tunnel. The tested system was built on the basis of heat gain in a cascade manner. The first step is to heat the water in the storage tank using the solar collectors. The second stage is the use of a heat pump (HP) in order to heat the diaphragm exchangers. The lower HP heat source is a cascade first stage buffer. In the storage tank, diaphragm exchangers used for solar collectors and heat pumps are installed. The research was carried out at a research station located in the University of Agriculture in Cracow. The aim was to perform an analysis of the efficiency of a hybrid system for the heating of a foil tunnel in the months from May to September. The efficiency of the entire hybrid system was calculated as the relation of the effect obtained in reference to the electrical power used to drive the heat pump components (compressor drive, circulation pump), circulation pumps and fans installed in the diaphragm heaters. The resulting effect was the amount of heat supplied to the interior of the object as a result of the internal air being forced through the diaphragm exchangers.

  11. Analysis of the efficiency of a hybrid foil tunnel heating system

    Directory of Open Access Journals (Sweden)

    Kurpaska Sławomir

    2017-01-01

    Full Text Available The paper analyzes the efficiency of the hybrid system used to heat the foil tunnel. The tested system was built on the basis of heat gain in a cascade manner. The first step is to heat the water in the storage tank using the solar collectors. The second stage is the use of a heat pump (HP in order to heat the diaphragm exchangers. The lower HP heat source is a cascade first stage buffer. In the storage tank, diaphragm exchangers used for solar collectors and heat pumps are installed. The research was carried out at a research station located in the University of Agriculture in Cracow. The aim was to perform an analysis of the efficiency of a hybrid system for the heating of a foil tunnel in the months from May to September. The efficiency of the entire hybrid system was calculated as the relation of the effect obtained in reference to the electrical power used to drive the heat pump components (compressor drive, circulation pump, circulation pumps and fans installed in the diaphragm heaters. The resulting effect was the amount of heat supplied to the interior of the object as a result of the internal air being forced through the diaphragm exchangers.

  12. System for the analysis of plant chromosomes

    International Nuclear Information System (INIS)

    Medina Martin, D.; Peraza Gonzalez, L.H.

    1996-01-01

    The paper describes a computer system for the automation workers of recognition analysis and interpretation of plant chromosomes. This system permit to carry out the analysis in a more comfortable and faster way, using the image processing techniques

  13. Substitution dynamical systems spectral analysis

    CERN Document Server

    Queffélec, Martine

    2010-01-01

    This volume mainly deals with the dynamics of finitely valued sequences, and more specifically, of sequences generated by substitutions and automata. Those sequences demonstrate fairly simple combinatorical and arithmetical properties and naturally appear in various domains. As the title suggests, the aim of the initial version of this book was the spectral study of the associated dynamical systems: the first chapters consisted in a detailed introduction to the mathematical notions involved, and the description of the spectral invariants followed in the closing chapters. This approach, combined with new material added to the new edition, results in a nearly self-contained book on the subject. New tools - which have also proven helpful in other contexts - had to be developed for this study. Moreover, its findings can be concretely applied, the method providing an algorithm to exhibit the spectral measures and the spectral multiplicity, as is demonstrated in several examples. Beyond this advanced analysis, many...

  14. Wavelets as a tool for power system dynamic events analysis – State-of-the-art and future applications

    Directory of Open Access Journals (Sweden)

    Samir Avdaković

    2015-05-01

    Full Text Available Power system is constantly exposed to disturbances of varying intensity and cascading propagation of disturbance that can lead to partial or total power system blackout. Some of the consequences are network topology changes, outage of generator units or occurrence of low-frequency electromechanical oscillations (LFEO. One of the techniques for signal analysis and processing used in the past 20 years for power system disturbance analysis, and helped in better understanding of power system dynamic, is Wavelet Transform (WT. This work reviews WT applications for power system dynamic behavior analysis. With research made on vast literature it can be concluded that WT technique has different applications in disturbances identification and localization, LFEO identification and analysis, and assessment of active power imbalance.

  15. High-yield continuous production of nicotinic acid via nitrile hydratase–amidase cascade reactions using cascade CSMRs

    Czech Academy of Sciences Publication Activity Database

    Cantarella, L.; Gallifuoco, A.; Malandra, A.; Martínková, Ludmila; Spera, A.; Cantarella, M.

    2011-01-01

    Roč. 48, 4-5 (2011), 345-350 ISSN 0141-0229 R&D Projects: GA MŠk OC09046 Institutional research plan: CEZ:AV0Z50200510 Keywords : Nitrile hydratase-amidase cascade system * 3-Cyanopyridine bioconversion * Nicotinic acid Subject RIV: EE - Microbiology, Virology Impact factor: 2.367, year: 2011

  16. Successful Treatment Of Homozygous Familial Hypercholesterolemia Using Cascade Filtration Plasmapheresis

    Directory of Open Access Journals (Sweden)

    Fatih Kardas

    2012-12-01

    Full Text Available OBJECTIVE: The aim of our study is to discuss the efficacy of low-density lipoprotein-cholesterol (LDL-C apheresis procedure using the cascade filtration system for pediatric patients with homozygous familial hypercholesterolemia (FH, and to clarify the adverse effects and difficulties. METHODS: LDL apheresis using the cascade filtration system was performed in 3 pediatric patients with homozygous FH. In total, 120 apheresis sessions were performed for all patients. RESULTS: Cascade filtration therapy significantly reduced the mean LDL-C values from 418 ± 62 mg/dl to 145 ± 43 mg/dl (p<0.05. We determined an acute mean reduction in the plasma levels of total cholesterol (57.9%, LDL cholesterol (70.8%, and high-density lipoprotein (HDL cholesterol (40.7%. Treatments were well tolerated. The most frequent clinical adverse effects were hypotension in 3 sessions (2.5%, chills/feeling cold (1.7% in 2 sessions, and nausea and vomiting in 3 sessions (2.5%. CONCLUSION: Our experience with three patients using the cascade filtration system were, good clinical outcomes, laboratory findings, safety of usage, minor adverse effects and technical problems.

  17. Interband Cascade Laser Photon Noise

    Science.gov (United States)

    2009-09-01

    separated by an injection region composed of digitally graded Indium Arsenide (InAs)/ Aluminum Indium Antimonide (Al(In)Sb) multi-QWs. The active region...consists of coupled InAs, Gallium Indium Antimonide (GaInSb) and Gallium Antimonide (GaSb) QWs separated by Aluminum Antimonide (AlSb) barriers. Under... Antimonide AlInSb Aluminum Indium Antimonide cw constant wave DC direct current GaSb Gallium Antimonide IC Interband cascade InAs Indium Arsenide InSb

  18. Availability Cascades & the Sharing Economy

    DEFF Research Database (Denmark)

    Netter, Sarah

    2014-01-01

    attention. This conceptual paper attempts to explain the emergent focus on the sharing economy and associated business and consumption models by applying cascade theory. Risks associated with this behavior will be especially examined with regard to the sustainability claim of collaborative consumption....... With academics, practitioners, and civil society alike having a shared history in being rather fast in accepting new concepts that will not only provide business opportunities but also a good conscience, this study proposes a critical study of the implications of collaborative consumption, before engaging...

  19. Disaster Mythology and Availability Cascades

    Directory of Open Access Journals (Sweden)

    Lisa Grow Sun

    2013-04-01

    Full Text Available Sociological research conducted in the aftermath of natural disasters has uncovered a number of “disaster myths” – widely shared misconceptions about typical post-disaster human behavior. This paper discusses the possibility that perpetuation of disaster mythology reflects an “availability cascade,” defined in prior scholarship as a “self-reinforcing process of collective belief formation by which an expressed perception triggers a chain reaction that gives the perception increasing plausibility through its rising availability in public discourse.” (Kuran and Sunstein 1999. Framing the spread of disaster mythology as an availability cascade suggests that certain tools may be useful in halting the myths’ continued perpetuation. These tools include changing the legal and social incentives of so-called “availability entrepreneurs” – those principally responsible for beginning and perpetuating the cascade, as well as insulating decision-makers from political pressures generated by the availability cascade. This paper evaluates the potential effectiveness of these and other solutions for countering disaster mythology. Las investigaciones sociológicas realizadas tras los desastres naturales han hecho evidentes una serie de “mitos del desastre”, conceptos erróneos ampliamente compartidos sobre el comportamiento humano típico tras un desastre. Este artículo analiza la posibilidad de que la perpetuación de los mitos del desastre refleje una “cascada de disponibilidad”, definida en estudios anteriores como un “proceso de auto-refuerzo de la formación de una creencia colectiva, a través del que una percepción expresada produce una reacción en cadena que hace que la percepción sea cada vez más verosímil, a través de una mayor presencia en el discurso público” (Kuran y Sunstein 1999. Enmarcar la propagación de los mitos del desastre como una cascada de disponibilidad sugiere que ciertas herramientas pueden ser

  20. Adaptive Kernel Canonical Correlation Analysis Algorithms for Nonparametric Identification of Wiener and Hammerstein Systems

    Directory of Open Access Journals (Sweden)

    Ignacio Santamaría

    2008-04-01

    Full Text Available This paper treats the identification of nonlinear systems that consist of a cascade of a linear channel and a nonlinearity, such as the well-known Wiener and Hammerstein systems. In particular, we follow a supervised identification approach that simultaneously identifies both parts of the nonlinear system. Given the correct restrictions on the identification problem, we show how kernel canonical correlation analysis (KCCA emerges as the logical solution to this problem. We then extend the proposed identification algorithm to an adaptive version allowing to deal with time-varying systems. In order to avoid overfitting problems, we discuss and compare three possible regularization techniques for both the batch and the adaptive versions of the proposed algorithm. Simulations are included to demonstrate the effectiveness of the presented algorithm.

  1. Ion-implantation dense cascade data

    International Nuclear Information System (INIS)

    Winterbon, K.B.

    1983-04-01

    A tabulation is given of data useful in estimating various aspects of ion-implantation cascades in the nuclear stopping regime, particularly with respect to nonlinearity of the cascade at high energy densities. The tabulation is restricted to self-ion implantation. Besides power-cross-section cascade dimensions, various material properties are included. Scaling of derived quantities with input data is noted, so one is not limited to the values assumed by the author

  2. Two sustainable energy system analysis models

    DEFF Research Database (Denmark)

    Lund, Henrik; Goran Krajacic, Neven Duic; da Graca Carvalho, Maria

    2005-01-01

    This paper presents a comparative study of two energy system analysis models both designed with the purpose of analysing electricity systems with a substantial share of fluctuating renewable energy.......This paper presents a comparative study of two energy system analysis models both designed with the purpose of analysing electricity systems with a substantial share of fluctuating renewable energy....

  3. Tank waste remediation system mission analysis report

    International Nuclear Information System (INIS)

    Acree, C.D.

    1998-01-01

    The Tank Waste Remediation System Mission Analysis Report identifies the initial states of the system and the desired final states of the system. The Mission Analysis Report identifies target measures of success appropriate to program-level accomplishments. It also identifies program-level requirements and major system boundaries and interfaces

  4. Bifurcation Analysis and Chaos Control in a Discrete Epidemic System

    Directory of Open Access Journals (Sweden)

    Wei Tan

    2015-01-01

    Full Text Available The dynamics of discrete SI epidemic model, which has been obtained by the forward Euler scheme, is investigated in detail. By using the center manifold theorem and bifurcation theorem in the interior R+2, the specific conditions for the existence of flip bifurcation and Neimark-Sacker bifurcation have been derived. Numerical simulation not only presents our theoretical analysis but also exhibits rich and complex dynamical behavior existing in the case of the windows of period-1, period-3, period-5, period-6, period-7, period-9, period-11, period-15, period-19, period-23, period-34, period-42, and period-53 orbits. Meanwhile, there appears the cascade of period-doubling 2, 4, 8 bifurcation and chaos sets from the fixed point. These results show the discrete model has more richer dynamics compared with the continuous model. The computations of the largest Lyapunov exponents more than 0 confirm the chaotic behaviors of the system x→x+δ[rN(1-N/K-βxy/N-(μ+mx], y→y+δ[βxy/N-(μ+dy]. Specifically, the chaotic orbits at an unstable fixed point are stabilized by using the feedback control method.

  5. A non-conventional isotope separation cascade without any mixing: net cascade

    International Nuclear Information System (INIS)

    Zeng Shi; Jiang Dongjun; Ying Zhengen

    2012-01-01

    A component has different concentrations in the incoming flows at a confluent point in all existing isotope separations cascades for multi-component isotope separation and mixing is inevitable, which results in deterioration of separation performance of the separation cascade. However, realization of no-mixing at a confluent point is impossible with a conventional cascade. A non-conventional isotope separation cascade, net cascade, is found to be able to realize no mixings for all components at confluent points, and its concept is further developed here. No-mixing is fulfilled by requiring symmetrical separation of two specified key components at every stage, and the procedure of realizing no-mixing is presented in detail. Some properties of net cascade are investigated preliminarily, and the results demonstrated the no-mixing property is indeed realized. Net cascade is the only separation cascade that so far possesses the no-mixing property. (authors)

  6. Integration of a complex regulatory cascade involving the SirA/BarA and Csr global regulatory systems that controls expression of the Salmonella SPI-1 and SPI-2 virulence regulons through HilD.

    Science.gov (United States)

    Martínez, Luary C; Yakhnin, Helen; Camacho, Martha I; Georgellis, Dimitris; Babitzke, Paul; Puente, José L; Bustamante, Víctor H

    2011-06-01

    Salmonella pathogenicity islands 1 and 2 (SPI-1 and SPI-2) play key roles in the pathogenesis of Salmonella enterica. Previously, we showed that when Salmonella grows in Luria-Bertani medium, HilD, encoded in SPI-1, first induces the expression of hilA, located in SPI-1, and subsequently of the ssrAB operon, located in SPI-2. These genes code for HilA and the SsrA/B two-component system, the positive regulators of the SPI-1 and SPI-2 regulons respectively. In this study, we demonstrate that CsrA, a global regulatory RNA binding protein, post-transcriptionally regulates hilD expression by directly binding near the Shine-Dalgarno and translation initiation codon sequences of the hilD mRNA, preventing its translation and leading to its accelerated turnover. Negative regulation is counteracted by the global SirA/BarA two-component system, which directly activates the expression of CsrB and CsrC, two non-coding regulatory RNAs that sequester CsrA, thereby preventing it from binding to its target mRNAs. Our results illustrate the integration of global and specific regulators into a multifactorial regulatory cascade controlling the expression of virulence genes acquired by horizontal transfer events. © 2011 Blackwell Publishing Ltd.

  7. Lifespans of Cascade Arc volcanoes

    Science.gov (United States)

    Calvert, A. T.

    2015-12-01

    Compiled argon ages reveal inception, eruptive episodes, ages, and durations of Cascade stratovolcanoes and their ancestral predecessors. Geologic mapping and geochronology show that most Cascade volcanoes grew episodically on multiple scales with periods of elevated behavior lasting hundreds of years to ca. 100 kyr. Notable examples include the paleomag-constrained, few-hundred-year-long building of the entire 15-20 km3 Shastina edifice at Mt. Shasta, the 100 kyr-long episode that produced half of Mt. Rainier's output, and the 30 kyr-long episode responsible for all of South and Middle Sister. Despite significant differences in timing and rates of construction, total durations of active and ancestral volcanoes at discrete central-vent locations are similar. Glacier Peak, Mt. Rainier, Mt. Adams, Mt. Hood, and Mt. Mazama all have inception ages of 400-600 ka. Mt. St. Helens, Mt. Jefferson, Newberry Volcano, Mt. Shasta and Lassen Domefield have more recent inception ages of 200-300 ka. Only the Sisters cluster and Mt. Baker have established eruptive histories spanning less than 50 kyr. Ancestral volcanoes centered 5-20 km from active stratocones appear to have similar total durations (200-600 kyr), but are less well exposed and dated. The underlying mechanisms governing volcano lifecycles are cryptic, presumably involving tectonic and plumbing changes and perhaps circulation cycles in the mantle wedge, but are remarkably consistent along the arc.

  8. Modeling and Vulnerability Analysis of Cyber-Physical Power Systems Considering Network Topology and Power Flow Properties

    Directory of Open Access Journals (Sweden)

    Jia Guo

    2017-01-01

    Full Text Available Conventional power systems are developing into cyber-physical power systems (CPPS with wide applications of communication, computer and control technologies. However, multiple practical cases show that the failure of cyber layers is a major factor leading to blackouts. Therefore, it is necessary to discuss the cascading failure process considering cyber layer failures and analyze the vulnerability of CPPS. In this paper, a CPPS model, which consists of cyber layer, physical layer and cyber-physical interface, is presented using complex network theory. Considering power flow properties, the impacts of cyber node failures on the cascading failure propagation process are studied. Moreover, two vulnerability indices are established from the perspective of both network structure and power flow properties. A vulnerability analysis method is proposed, and the CPPS performance before and after cascading failures is analyzed by the proposed method to calculate vulnerability indices. In the case study, three typical scenarios are analyzed to illustrate the method, and vulnerabilities under different interface strategies and attack strategies are compared. Two thresholds are proposed to value the CPPS vulnerability roughly. The results show that CPPS is more vulnerable under malicious attacks and cyber nodes with high indices are vulnerable points which should be reinforced.

  9. Emergence of a turbulent cascade in a quantum gas

    Science.gov (United States)

    Navon, Nir; Gaunt, Alexander L.; Smith, Robert P.; Hadzibabic, Zoran

    2016-11-01

    A central concept in the modern understanding of turbulence is the existence of cascades of excitations from large to small length scales, or vice versa. This concept was introduced in 1941 by Kolmogorov and Obukhov, and such cascades have since been observed in various systems, including interplanetary plasmas, supernovae, ocean waves and financial markets. Despite much progress, a quantitative understanding of turbulence remains a challenge, owing to the interplay between many length scales that makes theoretical simulations of realistic experimental conditions difficult. Here we observe the emergence of a turbulent cascade in a weakly interacting homogeneous Bose gas—a quantum fluid that can be theoretically described on all relevant length scales. We prepare a Bose-Einstein condensate in an optical box, drive it out of equilibrium with an oscillating force that pumps energy into the system at the largest length scale, study its nonlinear response to the periodic drive, and observe a gradual development of a cascade characterized by an isotropic power-law distribution in momentum space. We numerically model our experiments using the Gross-Pitaevskii equation and find excellent agreement with the measurements. Our experiments establish the uniform Bose gas as a promising new medium for investigating many aspects of turbulence, including the interplay between vortex and wave turbulence, and the relative importance of quantum and classical effects.

  10. Plasma data analysis using statistical analysis system

    International Nuclear Information System (INIS)

    Yoshida, Z.; Iwata, Y.; Fukuda, Y.; Inoue, N.

    1987-01-01

    Multivariate factor analysis has been applied to a plasma data base of REPUTE-1. The characteristics of the reverse field pinch plasma in REPUTE-1 are shown to be explained by four independent parameters which are described in the report. The well known scaling laws F/sub chi/ proportional to I/sub p/, T/sub e/ proportional to I/sub p/, and tau/sub E/ proportional to N/sub e/ are also confirmed. 4 refs., 8 figs., 1 tab

  11. Systems Analysis and Design: Know Your Audience

    Science.gov (United States)

    Reinicke, Bryan A.

    2012-01-01

    Systems analysis and design (SAD) classes are required in both Information Systems and Accounting programs, but these audiences have very different needs for these skills. This article will review the requirements for SAD within each of these disciplines and compare and contrast the different requirements for teaching systems analysis and design…

  12. Safety analysis of reactor's cooling system

    International Nuclear Information System (INIS)

    1999-01-01

    Results of the analysis of reactor's RBMK-1500 coolant system during normal operation mode, hydrodynamic testing and in the case of earthquake are presented. Analysis was performed using RELAP5 code. Calculations showed the most vulnerable place in the reactor's coolant system. It was found that in the case of earthquake the horizontal support system of drum separator could be damaged

  13. Centrifugal separator cascade connected in zigzag manner

    International Nuclear Information System (INIS)

    Kai, Tsunetoshi; Inoue, Yoshiya; Oya, Akio; Nagakura, Masaaki.

    1974-01-01

    Object: To effectively accommodate centrifugal separators of the entire cascade within the available space in a plant by freely selecting perpendicular direction of connection of the centrifugal separator. Structure: Centrifugal separators are connected in zigzag fashion by using a single header for each stage so that in a rectangular shape the entire cascade is arranged. (Kamimura, M.)

  14. Cascade Harvest’ red raspberry

    Science.gov (United States)

    Cascade Harvest’ is a new floricane fruiting raspberry cultivar (Rubus idaeus L.) jointly released by Washington State University (WSU), Oregon State University (OSU) and the U.S. Department of Agriculture (USDA). ‘Cascade Harvest’ produces a high yield of large, firm fruit suited to machine harves...

  15. Tripartite correlations over two octaves from cascaded harmonic generation

    Science.gov (United States)

    Olsen, M. K.

    2018-03-01

    We analyse the output quantum tripartite correlations from an intracavity nonlinear optical system which uses cascaded nonlinearities to produce both second and fourth harmonic outputs from an input field at the fundamental frequency. Using fully quantum equations of motion, we investigate two parameter regimes and show that the system produces tripartite inseparability, entanglement and EPR steering, with the detection of these depending on the correlations being considered.

  16. Two energy system analysis - tools

    DEFF Research Database (Denmark)

    Lund, Henrik; Andersen, Anders N.; Antonoff, Jayson

    2004-01-01

    The chapter illustrates some of the different types of problems that must be solved when analysing energy systems.......The chapter illustrates some of the different types of problems that must be solved when analysing energy systems....

  17. Stochastic Reachability Analysis of Hybrid Systems

    CERN Document Server

    Bujorianu, Luminita Manuela

    2012-01-01

    Stochastic reachability analysis (SRA) is a method of analyzing the behavior of control systems which mix discrete and continuous dynamics. For probabilistic discrete systems it has been shown to be a practical verification method but for stochastic hybrid systems it can be rather more. As a verification technique SRA can assess the safety and performance of, for example, autonomous systems, robot and aircraft path planning and multi-agent coordination but it can also be used for the adaptive control of such systems. Stochastic Reachability Analysis of Hybrid Systems is a self-contained and accessible introduction to this novel topic in the analysis and development of stochastic hybrid systems. Beginning with the relevant aspects of Markov models and introducing stochastic hybrid systems, the book then moves on to coverage of reachability analysis for stochastic hybrid systems. Following this build up, the core of the text first formally defines the concept of reachability in the stochastic framework and then...

  18. Availability Cascades & the Sharing Economy

    DEFF Research Database (Denmark)

    Netter, Sarah

    2014-01-01

    In search of a new concept that will provide answers to as to how modern societies should not only make sense but also resolve the social and environmental problems linked with our modes of production and consumption, collaborative consumption and the sharing economy are increasingly attracting...... attention. This conceptual paper attempts to explain the emergent focus on the sharing economy and associated business and consumption models by applying cascade theory. Risks associated with this behavior will be especially examined with regard to the sustainability claim of collaborative consumption....... With academics, practitioners, and civil society alike having a shared history in being rather fast in accepting new concepts that will not only provide business opportunities but also a good conscience, this study proposes a critical study of the implications of collaborative consumption, before engaging...

  19. Time-dependent intranuclear cascade model

    International Nuclear Information System (INIS)

    Barashenkov, V.S.; Kostenko, B.F.; Zadorogny, A.M.

    1980-01-01

    An intranuclear cascade model with explicit consideration of the time coordinate in the Monte Carlo simulation of the development of a cascade particle shower has been considered. Calculations have been performed using a diffuse nuclear boundary without any step approximation of the density distribution. Changes in the properties of the target nucleus during the cascade development have been taken into account. The results of these calculations have been compared with experiment and with the data which had been obtained by means of a time-independent cascade model. The consideration of time improved agreement between experiment and theory particularly for high-energy shower particles; however, for low-energy cascade particles (with grey and black tracks in photoemulsion) a discrepancy remains at T >= 10 GeV. (orig.)

  20. Cascade Error Projection: An Efficient Hardware Learning Algorithm

    Science.gov (United States)

    Duong, T. A.

    1995-01-01

    A new learning algorithm termed cascade error projection (CEP) is presented. CEP is an adaption of a constructive architecture from cascade correlation and the dynamical stepsize of A/D conversion from the cascade back propagation algorithm.

  1. Experimental study of flow through compressor Cascade

    Directory of Open Access Journals (Sweden)

    Satyam Panchal

    2017-09-01

    Full Text Available The objective of this research work is to study the behaviour of flow at the inlet, within the blade passage and at the exit of a compressor cascade. For this purpose, a cascade with six numbers of aerofoil blades was designed and constructed. The cascade was fitted on the cascade test tunnel. Out of six blades two were instrumented for measuring the pressure distribution on the pressure and suction surface. The blades had a parabolic camber line, with a maximum camber position at 40% of the chord from the leading edge of the blade. The profile of the blade was C4, height of the blade was 160 mm, chord length was 80 mm, camber angle was 45° and stagger angle was 30°. Similarly, the length of the cascade was 300 mm, span was 160 mm, pitch was 60 mm, the actual chord of the cascade was 80 mm, the axial chord of the cascade was 70 mm, the stagger angle of the cascade was 30° and the pitch-chord ratio was 0.75. The data was taken and analyzed at −500% of the axial chord before the cascade, −25% of the axial chord before the leading edge, 25%, 50%, 75% and 150% of the axial chord from the leading edge of the blade. The readings were taken from the cascade wall to the mid span position along the pitch wise direction. The angle of incidence was also changed during the experiment and varied from i=−50°, −30°, −10° to 5°.

  2. Risk and safety analysis of nuclear systems

    National Research Council Canada - National Science Library

    Lee, John C; McCormick, Norman J

    2011-01-01

    ...), and failure modes of systems. All of this material is general enough that it could be used in non-nuclear applications, although there is an emphasis placed on the analysis of nuclear systems...

  3. Importance analysis for reconfigurable systems

    International Nuclear Information System (INIS)

    Si, Shubin; Levitin, Gregory; Dui, Hongyan; Sun, Shudong

    2014-01-01

    Importance measures are used in reliability engineering to rank the system components according to their contributions to proper functioning of the entire system and to find the most effective ways of reliability enhancement. Traditionally, the importance measures do not consider the possible change of system structure with the improvement of specific component reliability. However, if a component's reliability changes, the optimal system structure/configuration may also change and the importance of the corresponding component will depend on the chosen structure. When the most promising component reliability improvement is determined, the component importance should be taken into account with respect to the possible structure changes. This paper studies the component reliability importance indices with respect to the changes of the optimal component sequencing. This importance measure indicates the critical components in providing the system reliability enhancement by both enhancing the component's reliability and reconfiguring the system. Examples of linear consecutive-k-out-of-n: F and G systems are considered to demonstrate the change of the component Birnbaum importance with the optimal system reconfiguration. The results show that the change of the importance index corresponds to the change of the system optimal configuration and the importance index can change not monotonically with the variation of the component reliability

  4. On first cycle slip time of phase-locked loops in cascade

    Science.gov (United States)

    Yuen, J. H.

    1974-01-01

    Precise measurement and spacecraft tracking are obtained by using phase-locked loops in cascade in two-way communications links. Statistics on cycle slip time are of vital importance in system planning and design. This paper presents: (1) results of a computer simulation study of the mean time to first cycle slip of cascade phase-locked loops preceded by bandpass limiters, and (2) the determination of probability distributions of cycle slip. Numerical results are obtained for a typical coherent communication system.

  5. EBT data acquisition and analysis system

    International Nuclear Information System (INIS)

    Burris, R.D.; Greenwood, D.E.; Stanton, J.S.; Geoffroy, K.A.

    1980-10-01

    This document describes the design and implementation of a data acquisition and analysis system for the EBT fusion experiment. The system includes data acquisition on five computers, automatic transmission of that data to a large, central data base, and a powerful data retrieval system. The system is flexible and easy to use, and it provides a fully documented record of the experiments

  6. Systems Analysis and Education Research Literature Review.

    Science.gov (United States)

    Geisinger, Robert W.

    Systems approaches, developed in World War II for military and business operations, have been applied increasingly to educational affairs. Educational systems analysis has received widespread usage in finance and accounting, and has also been successfully applied to information systems, instructional systems development, school design and…

  7. Boolean Models of Biological Processes Explain Cascade-Like Behavior

    Science.gov (United States)

    Chen, Hao; Wang, Guanyu; Simha, Rahul; Du, Chenghang; Zeng, Chen

    2016-01-01

    Biological networks play a key role in determining biological function and therefore, an understanding of their structure and dynamics is of central interest in systems biology. In Boolean models of such networks, the status of each molecule is either “on” or “off” and along with the molecules interact with each other, their individual status changes from “on” to “off” or vice-versa and the system of molecules in the network collectively go through a sequence of changes in state. This sequence of changes is termed a biological process. In this paper, we examine the common perception that events in biomolecular networks occur sequentially, in a cascade-like manner, and ask whether this is likely to be an inherent property. In further investigations of the budding and fission yeast cell-cycle, we identify two generic dynamical rules. A Boolean system that complies with these rules will automatically have a certain robustness. By considering the biological requirements in robustness and designability, we show that those Boolean dynamical systems, compared to an arbitrary dynamical system, statistically present the characteristics of cascadeness and sequentiality, as observed in the budding and fission yeast cell- cycle. These results suggest that cascade-like behavior might be an intrinsic property of biological processes. PMID:26821940

  8. Robustness of scale-free networks with various parameters against cascading failures

    Science.gov (United States)

    Yang, Zhirou; Liu, Jing

    2018-02-01

    Many crucial real-world networks could be modeled as scale-free networks, which play an important role in the human society. Once these functional network systems suffer from cascading failures, they may lead to the malfunction of the rest part of networks. In recent years, the researches on cascading failures of scale-free networks have drawn great attention, and many studies focused on modeling the cascading phenomena and studying how to improve the robustness of networks against failures. However, the scale-free networks used in most existing studies are with fixed network parameters including scaling exponent and assortativity, which is segmentary for depicting the functionality of networked systems comprehensively. Therefore, in this paper, a series of generated scale-free networks with a certain range of parameters is adopted to evaluate the robustness against cascading failures. In addition, to make an accurate description of the ability of scale-free networks against cascading failures, we propose a link-based robustness index. The results show that influenced by the network structure, the enlargement of assortativity makes the networks weaker to resist node-based cascading failures, yet the impact on promoting link-based robustness is not clear enough. With higher scaling exponents, the tolerance of scale-free networks against link-based cascading failures decreases, however, it does not show obvious relation to node-based robustness.

  9. Coupled analysis of floating production systems

    Energy Technology Data Exchange (ETDEWEB)

    Garrett, D.L. [Stress Engineering Services, Houston, TX (United States)

    2005-05-01

    Fully coupled global analysis of Floating Production Systems, including the vessel, the mooring system and the riser system is described. Design of the system can be a daunting task, involving more than 1000 load cases for global analysis. The primary driver for the mooring system and for the riser system is motion of the vessel. Vessel motions are driven by environmental forces, but are restrained by forces from the mooring and riser systems. Numerical models and procedures that provide accurate and efficient global modeling of the Floating Production System are presented. Both Time Domain and Frequency Domain procedures are included. The accuracy and efficiency of the procedures are illustrated in an example: a large semi with 16 mooring lines and 20 risers. The procedures provide the accuracy and efficiency for use of fully coupled analysis in design of Floating Production Systems from concept selection to final design, installation and operation. (Author)

  10. Smart geo-energy village development by using cascade direct use of geothermal energy in Bonjol, West Sumatera

    Science.gov (United States)

    Prasetya, Novrisal; Erwinsyah Umra Lubis, Defry; Raharjo, Dharmawan; Miryani Saptadji, Nenny; Pratama, Heru Berian

    2017-12-01

    West Sumatera is a province which has a huge geothermal potential - approximately 6% of Indonesia’s total geothermal potential which equals to 1,656 MWe. One of the significant reserves located in Bonjol subdistrict which accounts for more than 50 MWe. The energy from geothermal manifestation in Bonjol can be utilized prior to indirect development. Manifestation at the rate 3 kg/s and 87 °C will flow to cascading system consisting several applications, arranged in order from high to low temperature to efficiently use the excessive energy. The direct use application selected is based on the best potential commodities as well as temperature constraint of heat source. The objective of this paper is to perform a conceptual design for the first cascade direct use of geothermal energy in Indonesia to establish Bonjol Smart Geo-Energy Village which will be transformed as the center of agricultural, stockbreeding, tourism as well as cultural site. A comprehenssive research was performed through remote survey area, evaluation featured product, analysis of heat loss and heat exchange in cascade system. From potential commodities, the three applications selected are cocoa drying and egg hatching incubation machine as well as new tourism site called Terapi Panas Bumi. The optimum temperature for cocoa drying is 62°C with the moisture content 7% which consumes 78 kW for one tones cocoa dried. Whereas, egg incubation system consists of two chamber with the same temperature 40°C for each room and relative humidity 55% and 70%. For the last stage, Terapi Panas Bumi works in temperature 40°C. Based on the result technical and economical aspect, it exhibits cascade direct use of geothermal energy is very recommended to develop.

  11. P-I snake venom metalloproteinase is able to activate the complement system by direct cleavage of central components of the cascade.

    Directory of Open Access Journals (Sweden)

    Giselle Pidde-Queiroz

    Full Text Available BACKGROUND: Snake Venom Metalloproteinases (SVMPs are amongst the key enzymes that contribute to the high toxicity of snake venom. We have recently shown that snake venoms from the Bothrops genus activate the Complement system (C by promoting direct cleavage of C-components and generating anaphylatoxins, thereby contributing to the pathology and spread of the venom. The aim of the present study was to isolate and characterize the C-activating protease from Bothrops pirajai venom. RESULTS: Using two gel-filtration chromatography steps, a metalloproteinase of 23 kDa that activates Complement was isolated from Bothrops pirajai venom. The mass spectrometric identification of this protein, named here as C-SVMP, revealed peptides that matched sequences from the P-I class of SVMPs. C-SVMP activated the alternative, classical and lectin C-pathways by cleaving the α-chain of C3, C4 and C5, thereby generating anaphylatoxins C3a, C4a and C5a. In vivo, C-SVMP induced consumption of murine complement components, most likely by activation of the pathways and/or by direct cleavage of C3, leading to a reduction of serum lytic activity. CONCLUSION: We show here that a P-I metalloproteinase from Bothrops pirajai snake venom activated the Complement system by direct cleavage of the central C-components, i.e., C3, C4 and C5, thereby generating biologically active fragments, such as anaphylatoxins, and by cleaving the C1-Inhibitor, which may affect Complement activation control. These results suggest that direct complement activation by SVMPs may play a role in the progression of symptoms that follow envenomation.

  12. P-I Snake Venom Metalloproteinase Is Able to Activate the Complement System by Direct Cleavage of Central Components of the Cascade

    Science.gov (United States)

    Pidde-Queiroz, Giselle; Magnoli, Fábio Carlos; Portaro, Fernanda C. V.; Serrano, Solange M. T.; Lopes, Aline Soriano; Paes Leme, Adriana Franco; van den Berg, Carmen W.; Tambourgi, Denise V.

    2013-01-01

    Background Snake Venom Metalloproteinases (SVMPs) are amongst the key enzymes that contribute to the high toxicity of snake venom. We have recently shown that snake venoms from the Bothrops genus activate the Complement system (C) by promoting direct cleavage of C-components and generating anaphylatoxins, thereby contributing to the pathology and spread of the venom. The aim of the present study was to isolate and characterize the C-activating protease from Bothrops pirajai venom. Results Using two gel-filtration chromatography steps, a metalloproteinase of 23 kDa that activates Complement was isolated from Bothrops pirajai venom. The mass spectrometric identification of this protein, named here as C-SVMP, revealed peptides that matched sequences from the P-I class of SVMPs. C-SVMP activated the alternative, classical and lectin C-pathways by cleaving the α-chain of C3, C4 and C5, thereby generating anaphylatoxins C3a, C4a and C5a. In vivo, C-SVMP induced consumption of murine complement components, most likely by activation of the pathways and/or by direct cleavage of C3, leading to a reduction of serum lytic activity. Conclusion We show here that a P-I metalloproteinase from Bothrops pirajai snake venom activated the Complement system by direct cleavage of the central C-components, i.e., C3, C4 and C5, thereby generating biologically active fragments, such as anaphylatoxins, and by cleaving the C1-Inhibitor, which may affect Complement activation control. These results suggest that direct complement activation by SVMPs may play a role in the progression of symptoms that follow envenomation. PMID:24205428

  13. Cascaded Amplitude Modulations in Sound Texture Perception

    Directory of Open Access Journals (Sweden)

    Richard McWalter

    2017-09-01

    Full Text Available Sound textures, such as crackling fire or chirping crickets, represent a broad class of sounds defined by their homogeneous temporal structure. It has been suggested that the perception of texture is mediated by time-averaged summary statistics measured from early auditory representations. In this study, we investigated the perception of sound textures that contain rhythmic structure, specifically second-order amplitude modulations that arise from the interaction of different modulation rates, previously described as “beating” in the envelope-frequency domain. We developed an auditory texture model that utilizes a cascade of modulation filterbanks that capture the structure of simple rhythmic patterns. The model was examined in a series of psychophysical listening experiments using synthetic sound textures—stimuli generated using time-averaged statistics measured from real-world textures. In a texture identification task, our results indicated that second-order amplitude modulation sensitivity enhanced recognition. Next, we examined the contribution of the second-order modulation analysis in a preference task, where the proposed auditory texture model was preferred over a range of model deviants that lacked second-order modulation rate sensitivity. Lastly, the discriminability of textures that included second-order amplitude modulations appeared to be perceived using a time-averaging process. Overall, our results demonstrate that the inclusion of second-order modulation analysis generates improvements in the perceived quality of synthetic textures compared to the first-order modulation analysis considered in previous approaches.

  14. Transcriptome Analysis of Porcine PBMCs Reveals the Immune Cascade Response and Gene Ontology Terms Related to Cell Death and Fibrosis in the Progression of Liver Failure

    Directory of Open Access Journals (Sweden)

    YiMin Zhang

    2018-01-01

    Full Text Available Background. The key gene sets involved in the progression of acute liver failure (ALF, which has a high mortality rate, remain unclear. This study aims to gain a deeper understanding of the transcriptional response of peripheral blood mononuclear cells (PBMCs following ALF. Methods. ALF was induced by D-galactosamine (D-gal in a porcine model. PBMCs were separated at time zero (baseline group, 36 h (failure group, and 60 h (dying group after D-gal injection. Transcriptional profiling was performed using RNA sequencing and analysed using DAVID bioinformatics resources. Results. Compared with the baseline group, 816 and 1,845 differentially expressed genes (DEGs were identified in the failure and dying groups, respectively. A total of five and two gene ontology (GO term clusters were enriched in 107 GO terms in the failure group and 154 GO terms in the dying group. These GO clusters were primarily immune-related, including genes regulating the inflammasome complex and toll-like receptor signalling pathways. Specifically, GO terms related to cell death, including apoptosis, pyroptosis, and autophagy, and those related to fibrosis, coagulation dysfunction, and hepatic encephalopathy were enriched. Seven Kyoto Encyclopedia of Genes and Genomes (KEGG pathways, cytokine-cytokine receptor interaction, hematopoietic cell lineage, lysosome, rheumatoid arthritis, malaria, and phagosome and pertussis pathways were mapped for DEGs in the failure group. All of these seven KEGG pathways were involved in the 19 KEGG pathways mapped in the dying group. Conclusion. We found that the dramatic PBMC transcriptome changes triggered by ALF progression was predominantly related to immune responses. The enriched GO terms related to cell death, fibrosis, and so on, as indicated by PBMC transcriptome analysis, seem to be useful in elucidating potential key gene sets in the progression of ALF. A better understanding of these gene sets might be of preventive or

  15. Observation and analysis of cosmic electromagnetic cascades detected in lead photoemulsion chamber of the Brazil-Japan cooperation, exposed in Monte Chacaltaya, Bolivia (altitude 5200m, air pressure 550 gr.cm-2)

    International Nuclear Information System (INIS)

    Bastos, C.A.

    1971-04-01

    The cosmic gamma radiations in the photoemulsion chamber for Brazil-Japan Cooperation are studied. These radiations reproduces the electromagnetic component of extensive air showers at the begining of its development through the atmosphere. The gamma radiations, which is 0 Π meson decay products emitted in nuclear interaction, are detected by electromagnetic cascades which are developed when they reach the photoemulsion chamber. Cosmic gamma radiations is a set of parallel electromagnetic cascades proceeding from nuclear interactions. The information about high energy nuclear interactions making possible to study the structure of extensive air showers at the beginning of its development and multiple meson production are obtained. (M.C.K.) [pt

  16. Collision cascades in Zr3Fe

    International Nuclear Information System (INIS)

    Howe, L.M.; Rainville, M.H.; Phillips, D.; Plattner, H.H.; Bonnett, J.D.

    1994-11-01

    The objective of the present research is to understand better the processes that control irradiation-induced phase changes and solute segregation in zirconium alloys. Previously, it was found that 0.5 - 1.5 MeV 40 Ar ion irradiations resulted in the conversion of the crystalline Zr 3 Fe orthorhombic phase to the amorphous state. In the present investigation, 15 - 1500 keV 209 Bi ion irradiations (10 11 - 10 14 ions cm -2 ) were performed to provide more detailed information on collision cascades in Zr 3 Fe. Consecutive ion bombardments with 1.5, 1.0 and 0.5 MeV 209 Bi ions showed that complete amorphization occurred from 35 K to at least 600 K. Low fluence (10 11 - 101 12 ions cm -2 ) irradiations performed at 35 - 40 K with 15 - 350 keV 209 Bi ions provided information on the nature of the damage produced within individual damage cascades. At high values for the average deposited-energy density θυ in the cascade, which correspond to low-energy heavy-ion implants (e.g., 15-30 keV in Zr 3 Fe), the visible damage produced in a cascade consisted of single damaged region. With decreasing values of θυ (i.e., increasing ion implant energies), there was an increasing tendency for multiple damaged regions (subcascades) to form within a main cascade. The visible damaged regions appeared to be amorphous. It was also found that as the Bi ion energy increased (θυ decreased), the fraction of the theoretical collision-cascade volume that was occupied by the visible damage regions within a cascade decreased rapidly. The crystalline-to-amorphous transformation appeared to be the result of direct amorphization within the collision cascades and a critical defect concentration being reached in the cascade overlap regions, thus producing additional amorphous regions. (author). 30 refs., 2 tabs., 3 figs

  17. Distributed dual-parameter optical fiber sensor based on cascaded microfiber Fabry-Pérot interferometers

    Science.gov (United States)

    Xiang, Yang; Luo, Yiyang; Zhang, Wei; Liu, Deming; Sun, Qizhen

    2017-04-01

    We propose and demonstrate a distributed fiber sensor based on cascaded microfiber Fabry-Perot interferometers (MFPI) for simultaneous refractive index (SRI) and temperature measurement. By employing MFPI which is fabricated by taper-drawing the center of a uniform fiber Bragg grating (FBG) on standard fiber into a section of microfiber, dual parameters including SRI and temperature can be detected through demodulating the reflection spectrum of the MFPI. Further, wavelength-division-multiplexing (WDM) is applied to realize distributed dual-parameter fiber sensor by using cascaded MFPIs with different Bragg wavelengths. A prototype sensor system with 5 cascaded MFPIs is constructed to experimentally demonstrate the sensing performance.

  18. Segregation of the anodic microbial communities in a microbial fuel cell cascade

    Directory of Open Access Journals (Sweden)

    Douglas eHodgson

    2016-05-01

    Full Text Available Metabolic interactions within microbial communities are essential for the efficient degradation of complex organic compounds, and underpin natural phenomena driven by microorganisms, such as the recycling of carbon-, nitrogen-, and sulphur-containing molecules. These metabolic interactions ultimately determine the function, activity and stability of the community, and therefore their understanding would be essential to steer processes where microbial communities are involved. This is exploited in the design of microbial fuel cells (MFCs, bioelectrochemical devices that convert the chemical energy present in substrates into electrical energy through the metabolic activity of microorganisms, either single species or communities. In this work, we analysed the evolution of the microbial community structure in a cascade of microbial fuel cells (MFCs inoculated with an anaerobic microbial community and continuously fed with a complex medium. The analysis of the composition of the anodic communities revealed the establishment of different communities in the anodes of the hydraulically connected MFCs, with a decrease in the abundance of fermentative taxa and a concurrent increase in respiratory taxa along the cascade. The analysis of the metabolites in the anodic suspension showed a metabolic shift between the first and last MFC, confirming the segregation of the anodic communities. Those results suggest a metabolic interaction mechanism between the predominant fermentative bacteria at the first stages of the cascade and the anaerobic respiratory electrogenic population in the latter stages, which is reflected in the observed increase in power output. We show that our experimental system represents an ideal platform for optimization of processes where the degradation of complex substrates is involved, as well as a potential tool for the study of metabolic interactions in complex microbial communities.

  19. Systems Analysis Department annual progress report 1998

    DEFF Research Database (Denmark)

    1999-01-01

    The report describes the work of the Systems Analysis Department at Risø National Laboratory during 1998. The department undertakes research within Energy Systems Analysis, Integrated Energy, Environment and Development Planning - UNEP Centre, IndustrialSafety and Reliability, Man/Machine Interac....../Machine Interaction, and Technology Scenarios. The report includes lists of publications, lectures, committees and staff members....

  20. Systems Analysis Department annual progress report 1999

    DEFF Research Database (Denmark)

    2000-01-01

    This report describes the work of the Systems Analysis Department at Risø National Laboratory during 1999. The department is undertaking research within Energy Systems Analysis, Energy, Environment and Development Planning - UNEP Centre, Safety,Realiability and Human Factors, and Technology...

  1. Systems Analysis department. Annual progress report 1997

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, Hans; Olsson, Charlotte; Petersen, Kurt E.

    1998-03-01

    The report describes the work of the Systems Analysis Department at Risoe National Laboratory during 1997. The department is undertaking research within Energy systems Analysis, Integrated Energy, Environment and Development Planning - UNEP Centre, Industrial Safety and Reliability and Man/Machine Interaction. The report includes lists of publications lectures, committees and staff members. (au) 110 refs.

  2. Systems Analysis Department. Annual Report 2000

    Energy Technology Data Exchange (ETDEWEB)

    Duijm, N.J.; Jensen, E.; Larsen, H.; Olsson, C.

    2001-05-01

    This report describes the work of the Systems Analysis Department at Risoe National Laboratory during 2000. The department is undertaking research within Energy Systems Analysis, Energy, Environment and Development Planning - UNEP Centre, Safety, Reliability and Human Factors, and Technology Scenarios. The report includes summary statistics and lists of publications, committees and staff members. (au)

  3. Systems Analysis Department annual progress report 1998

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, Hans; Olsson, Charlotte; Loevborg, Leif [eds.

    1999-03-01

    The report describes the work of the Systems Analysis Department at Risoe National Laboratory during 1998. The department undertakes research within Energy Systems Analysis, Integrated Energy, Environment and Development Planning - UNEP Centre, Industrial Safety and Reliability, Man/Machine Interaction and Technology Scenarios. The report includes lists of publications, lectures, committees and staff members. (au) 111 refs.

  4. System Analysis Department. Annual Report 2002

    Energy Technology Data Exchange (ETDEWEB)

    Duijm, N.J.; Jensen, E.; Larsen, H.; Skipper, S. (eds.)

    2002-04-01

    This report describes the work of the Systems Analysis Department at Risoe National Laboratory during 2001. The department is undertaking research within Energy Systems Analysis, Energy, Environment and Development Planning - UNEP Centre, Safety, Reliability and Human Factors, and Technology Scenarios. The report includes summary statistics and lists of publications, committees and staff members. (au)

  5. Analysis and comparison of transportation security systems

    International Nuclear Information System (INIS)

    Rinne, R.L.

    1976-05-01

    The role of modeling in the analysis of transportation security systems is described. Various modeling approaches are outlined. The conflict model developed in Sandia Laboratories' Transportation Mode Analysis for the NRC Special Safeguards Study is used to demonstrate the capability of models to determine system sensitivities and compare alternatives

  6. Reliability analysis of flood defence systems

    NARCIS (Netherlands)

    Steenbergen, H.M.G.M.; Lassing, B.L.; Vrouwenvelder, A.C.W.M.; Waarts, P.H.

    2004-01-01

    In recent years an advanced program for the reliability analysis of flood defence systems has been under development. This paper describes the global data requirements for the application and the setup of the models. The analysis generates the probability of system failure and the contribution of

  7. Systems Analysis Department. Annual Report 2001

    Energy Technology Data Exchange (ETDEWEB)

    Duijm, N.J.; Jensen, E.; Larsen, H.; Skipper, S. (eds.)

    2002-04-01

    This report describes the work of the Systems Analysis Department at Risoe National Laboratory during 2001. The department is undertaking research within Energy Systems Analysis, Energy, Environment and Development Planning - UNEP Centre, Safety, Reliability and Human Factors, and Technology Scenarios. The report includes summary statistics and lists of publications, committees and staff members. (au)

  8. Types and concept analysis for legacy systems

    NARCIS (Netherlands)

    T. Kuipers (Tobias); L.M.F. Moonen (Leon)

    2000-01-01

    textabstractWe combine type inference and concept analysis in order to gain insight into legacy software systems. Type inference for Cobol yields the types for variables and program parameters. These types are used to perform mathematical concept analysis on legacy systems. We have developed

  9. Systems Analysis Department annual report 2002

    DEFF Research Database (Denmark)

    2003-01-01

    This report describes the work of the Systems Analysis Department at Risø National Laboratory during 2002. The department is undertaking research within Energy Systems Analysis, Energy, Environment and Development Planning – UNEP Centre, Safety,Reliability and Human Factors, and Technology Scenar...

  10. Systems Analysis Department annual report 2000

    DEFF Research Database (Denmark)

    2001-01-01

    This report describes the work of the Systems Analysis Department at Risø National Laboratory during 2000. The department is undertaking research within Energy Systems Analysis, Energy, Environment and Development Planning - UNEP Centre, Safety,Reliability and Human Factors, and Technology Scenar...

  11. Systems Analysis Department annual report 2001

    DEFF Research Database (Denmark)

    2002-01-01

    This report describes the work of the Systems Analysis Department at Risø National Laboratory during 2001. The department is undertaking research within Energy Systems Analysis, Energy, Environment and Development Planning - UNEP Centre, Safety,Reliability and Human Factors, and Technology Scenar...

  12. Systems Analysis Department. Annual Progress Report 1999

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, Hans; Olsson, Charlotte; Loevborg, Leif [eds.

    2000-03-01

    This report describes the work of the Systems Analysis Department at Risoe National Laboratory during 1999. The department is undertaking research within Energy Systems Analysis, Energy, Environment and Development Planning-UNEP Centre, Safety, Reliability and Human Factors, and Technology Scenarios. The report includes summary statistics and lists of publications, committees and staff members. (au)

  13. Systems Analysis Department. Annual Report 2003

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, H.; Olsson, C. (eds.)

    2004-04-01

    This report describes the work of the Systems Analysis Department at Risoe National Laboratory during 2003. The department is undertaking research within Energy Systems Analysis, Energy, Environment and Development Planning UNEP Centre, Safety, Reliability and Human Factors, and Technology Scenarios. The report includes summary statistics and list of staff members. (au)

  14. Dynamic analysis of nuclear safeguards systems

    International Nuclear Information System (INIS)

    Wilson, J.R.; Rasmuson, D.M.; Tingey, F.H.

    1978-01-01

    The assessment of the safeguards/adversary system poses a unique challenge as evolving technology affects the capabilities of both. The method discussed meets this challenge using a flexible analysis which can be updated by system personnel. The automatically constructed event tree provides a rapid overview analysis for initial assessment, evaluation of changes, cost/benefit study and inspection and audit

  15. Continuous Emission Monitoring of Tetrafluoromethane Using Quantum Cascade Lasers

    Directory of Open Access Journals (Sweden)

    Peter Geiser

    2016-04-01

    Full Text Available Recent developments in quantum cascade lasers have enabled the development of new sensors for in-situ applications that have so far only been possible with extractive systems. In this work, a sensor is presented using a unique Wavelength Modulation Spectroscopy approach to measure tetrafluoromethane, a strong greenhouse gas. The sensor was characterized in a laboratory environment indicating a long-term detection limit of 20 ppb·m and a short-term value of well below 10 ppb·m. To demonstrate the feasibility of the sensor in a real-world environment, it was installed at an Alcoa aluminum smelter. A co-located Fourier Transform Infrared Spectrometer allowed direct comparison measurements of both systems. General agreement between the two methods was observed, leading to the conclusion that the developed in-situ quantum cascade laser based sensor has the potential to continuously measure tetrafluoromethane at aluminum smelters.

  16. Reachability Analysis of Probabilistic Systems

    DEFF Research Database (Denmark)

    D'Argenio, P. R.; Jeanett, B.; Jensen, Henrik Ejersbo

    2001-01-01

    than the original model, and may safely refute or accept the required property. Otherwise, the abstraction is refined and the process repeated. As the numerical analysis involved in settling the validity of the property is more costly than the refinement process, the method profits from applying...... such numerical analysis on smaller state spaces. The method is significantly enhanced by a number of novel strategies: a strategy for reducing the size of the numerical problems to be analyzed by identification of so-called {essential states}, and heuristic strategies for guiding the refinement process....

  17. Cascade Baryon Spectrum from Lattice QCD

    International Nuclear Information System (INIS)

    Mathur, Nilmani; Bulava, John; Edwards, Robert; Engelson, Eric; Joo, Balint; Lichtl, Adam; Lin, Huey-Wen; Morningstar, Colin; Richards, David; Wallace, Stephen

    2008-01-01

    A comprehensive study of the cascade baryon spectrum using lattice QCD affords the prospect of predicting the masses of states not yet discovered experimentally, and determining the spin and parity of those states for which the quantum numbers are not yet known. The study of the cascades, containing two strange quarks, is particularly attractive for lattice QCD in that the chiral effects are reduced compared to states composed only of u/d quarks, and the states are typically narrow. We report preliminary results for the cascade spectrum obtained by using anisotropic Nf = 2 Wilson lattices with temporal lattice spacing 5.56 GeV?1.

  18. Optimization of the hydrofoil cascade and validation with quasi-analytical solution for hydraulic machinery

    Energy Technology Data Exchange (ETDEWEB)

    Frunza, T; Susan-Resiga, R [Department of Hydraulic Machinery, ' Politehnica' University of Timisoara Bv. Mihai Viteazu 1, RO-300222, Timisoara (Romania); Muntean, S; Bernad, S, E-mail: tfrunza@yahoo.co [Centre of Advanced Research in Engineering Sciences, Romanian Academy - Timisoara Branch, Bv. Mihai Viteazu 24, RO-300223, Timisoara (Romania)

    2010-08-15

    The paper presents the authors ongoing efforts to develop a robust and efficient numerical methodology, and the associated expert software, for analysis, design and optimization of hydrofoil cascades. We developed, so far, a Finite Element solver with streamfunction formulation for incompressible, inviscid and irrotational cascade flow, using a modern software infrastructure, and efficient implementation. Two test cases will be presented to evaluate the accuracy of our CASCADExpert code. In the first case, our code is tested for a thin hydrofoil cascade designed with the quasi-analytical approach. Second, the blade loading and thickness distributions obtain with our code from a given hydrofoil shape are used in an inverse design method. As a result, an optimized hydrofoil cascade is obtained. The pressure distribution on the original and optimized hydrofoil cascades is compared. We have applied the method in order to optimize the turbine and pump hydrofoil cascades, respectively. Consequently, a new method is developed in order to generate the optimized hydrofoil cascade geometry for hydraulic machinery.

  19. On Bayesian System Reliability Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Soerensen Ringi, M.

    1995-05-01

    The view taken in this thesis is that reliability, the probability that a system will perform a required function for a stated period of time, depends on a person`s state of knowledge. Reliability changes as this state of knowledge changes, i.e. when new relevant information becomes available. Most existing models for system reliability prediction are developed in a classical framework of probability theory and they overlook some information that is always present. Probability is just an analytical tool to handle uncertainty, based on judgement and subjective opinions. It is argued that the Bayesian approach gives a much more comprehensive understanding of the foundations of probability than the so called frequentistic school. A new model for system reliability prediction is given in two papers. The model encloses the fact that component failures are dependent because of a shared operational environment. The suggested model also naturally permits learning from failure data of similar components in non identical environments. 85 refs.

  20. On Bayesian System Reliability Analysis

    International Nuclear Information System (INIS)

    Soerensen Ringi, M.

    1995-01-01

    The view taken in this thesis is that reliability, the probability that a system will perform a required function for a stated period of time, depends on a person's state of knowledge. Reliability changes as this state of knowledge changes, i.e. when new relevant information becomes available. Most existing models for system reliability prediction are developed in a classical framework of probability theory and they overlook some information that is always present. Probability is just an analytical tool to handle uncertainty, based on judgement and subjective opinions. It is argued that the Bayesian approach gives a much more comprehensive understanding of the foundations of probability than the so called frequentistic school. A new model for system reliability prediction is given in two papers. The model encloses the fact that component failures are dependent because of a shared operational environment. The suggested model also naturally permits learning from failure data of similar components in non identical environments. 85 refs

  1. Power system reliability analysis using fault trees

    International Nuclear Information System (INIS)

    Volkanovski, A.; Cepin, M.; Mavko, B.

    2006-01-01

    The power system reliability analysis method is developed from the aspect of reliable delivery of electrical energy to customers. The method is developed based on the fault tree analysis, which is widely applied in the Probabilistic Safety Assessment (PSA). The method is adapted for the power system reliability analysis. The method is developed in a way that only the basic reliability parameters of the analysed power system are necessary as an input for the calculation of reliability indices of the system. The modeling and analysis was performed on an example power system consisting of eight substations. The results include the level of reliability of current power system configuration, the combinations of component failures resulting in a failed power delivery to loads, and the importance factors for components and subsystems. (author)

  2. Fundamentals and applications of systems reliability analysis

    International Nuclear Information System (INIS)

    Boesebeck, K.; Heuser, F.W.; Kotthoff, K.

    1976-01-01

    The lecture gives a survey on the application of methods of reliability analysis to assess the safety of nuclear power plants. Possible statements of reliability analysis in connection with specifications of the atomic licensing procedure are especially dealt with. Existing specifications of safety criteria are additionally discussed with the help of reliability analysis by the example of the reliability analysis of a reactor protection system. Beyond the limited application to single safety systems, the significance of reliability analysis for a closed risk concept is explained in the last part of the lecture. (orig./LH) [de

  3. Systems Engineering Analysis for Office Space Management

    Science.gov (United States)

    2017-09-01

    behavioral decision research CAE component acquisition executive CFL core function lead CFSP Core Function Support Plan DA decision analysis DAE...are more effective than less personnel. C. REQUIREMENTS ANALYSIS The systems engineering method applied to LAAFB is based on Kossiakoff’s (2011...program’s commitments support them. The systems engineering method was applied with an emphasis on requirements analysis to develop clear objectives for an

  4. Multichannel photonic mixing based on cascade carrier suppression

    Science.gov (United States)

    Xu, Fangxing

    2015-10-01

    Designed a multi-channel photonic mixing system based on cascade carrier suppression, which can achieve frequency conversions simultaneously for multi-channels, effectively inhibit the generation of third-order intermodulation, and significantly reduce the insertion loss in the conversion process. Meanwhile, a simulation with the software Optisystem has been done, indicating excellent frequency-conversion characteristics and good scalability of this scheme, that shows the microwave photonic frequency conversion can be a potential application for microwave signal parallel processing.

  5. Digital Speed Cascade Control, using Scilab / Xcos Environment

    Directory of Open Access Journals (Sweden)

    Petru Chioncel

    2016-10-01

    Full Text Available This paper presents an application of digital cascade control implemented in Scilab / Xcos environment, using a P type regulator for the position adjustment circuit, a PI controller for the speed circuit adjustment; the current respectively moments control circuits are rendered by elements of PT1 type. On this basis the program is done in Scilab and the related signal block diagram implemented in Xcos; through simulation, the step response of the system is analyzed for different sampling times.

  6. Dynamic Contingency Analysis Tool

    Energy Technology Data Exchange (ETDEWEB)

    2016-01-14

    The Dynamic Contingency Analysis Tool (DCAT) is an open-platform and publicly available methodology to help develop applications that aim to improve the capabilities of power system planning engineers to assess the impact and likelihood of extreme contingencies and potential cascading events across their systems and interconnections. Outputs from the DCAT will help find mitigation solutions to reduce the risk of cascading outages in technically sound and effective ways. The current prototype DCAT implementation has been developed as a Python code that accesses the simulation functions of the Siemens PSS/E planning tool (PSS/E). It has the following features: It uses a hybrid dynamic and steady-state approach to simulating the cascading outage sequences that includes fast dynamic and slower steady-state events. It integrates dynamic models with protection scheme models for generation, transmission, and load. It models special protection systems (SPSs)/remedial action schemes (RASs) and automatic and manual corrective actions. Overall, the DCAT attempts to bridge multiple gaps in cascading-outage analysis in a single, unique prototype tool capable of automatically simulating and analyzing cascading sequences in real systems using multiprocessor computers.While the DCAT has been implemented using PSS/E in Phase I of the study, other commercial software packages with similar capabilities can be used within the DCAT framework.

  7. Aspects of the QCD cascade

    International Nuclear Information System (INIS)

    Olsson, Magnus.

    1993-02-01

    A model is proposed for the production of transverse jets from diffractively excited protons. We propose that transverse jets can be obtained from gluonic bremsstrahlung in a way similar to the emission in DIS. Qualitative agreement is obtained between the model and the uncorrected data published by the UA8 collaboration. Perturbative QCD in the MLLA approximation is applied to multiple jet production in e + e - -annihilation. We propose modified evolution equations for deriving the jet cross sections, defined in the 'k t ' or 'Durham' algorithm. The mean number of jets as a function of the jet resolution is studied, and analytical predictions are compared to the results of MC simulations. We also study a set of differential-difference equations for multiplicity distributions in e + e - -annihilations, supplemented with appropriate boundary conditions. These equations take into account nonsingular terms in the GLAP splitting functions as well as kinematical constraints related to recoil effects. The presence of retarded terms imply that the cascade develops more slowly and reduces the fluctuations. The solutions agree well with MC simulations and experimental data. (authors)

  8. MHD stability analysis of helical system plasmas

    International Nuclear Information System (INIS)

    Nakamura, Yuji

    2000-01-01

    Several topics of the MHD stability studies in helical system plasmas are reviewed with respect to the linear and ideal modes mainly. Difference of the method of the MHD stability analysis in helical system plasmas from that in tokamak plasmas is emphasized. Lack of the cyclic (symmetric) coordinate makes an analysis more difficult. Recent topic about TAE modes in a helical system is also described briefly. (author)

  9. The Subject Analysis of Payment Systems Characteristics

    OpenAIRE

    Korobeynikova Olga Mikhaylovna

    2015-01-01

    The article deals with the analysis of payment systems aimed at identifying the categorical terminological apparatus, proving their specific features and revealing the impact of payment systems on the state of money turnover. On the basis of the subject analysis, the author formulates the definitions of a payment system (characterized by increasing speed of effecting payments, by the reduction of costs, by high degree of payments convenience for subjects of transactions, by security of paymen...

  10. Seismic analysis of nuclear piping system

    International Nuclear Information System (INIS)

    Shrivastava, S.K.; Pillai, K.R.V.; Nandakumar, S.

    1975-01-01

    To illustrate seismic analysis of nuclear power plant piping, a simple piping system running between two floors of the reactor building is assumed. Reactor building floor response is derived from time-history method. El Centre earthquake (1940) accelerogram is used for time-history analysis. The piping system is analysed as multimass lumped system. Behaviour of the pipe during the said earthquake is discussed. (author)

  11. A new cascade NN based method to short-term load forecast in deregulated electricity market

    International Nuclear Information System (INIS)

    Kouhi, Sajjad; Keynia, Farshid

    2013-01-01

    Highlights: • We are proposed a new hybrid cascaded NN based method and WT to short-term load forecast in deregulated electricity market. • An efficient preprocessor consist of normalization and shuffling of signals is presented. • In order to select the best inputs, a two-stage feature selection is presented. • A new cascaded structure consist of three cascaded NNs is used as forecaster. - Abstract: Short-term load forecasting (STLF) is a major discussion in efficient operation of power systems. The electricity load is a nonlinear signal with time dependent behavior. The area of electricity load forecasting has still essential need for more accurate and stable load forecast algorithm. To improve the accuracy of prediction, a new hybrid forecast strategy based on cascaded neural network is proposed for STLF. This method is consists of wavelet transform, an intelligent two-stage feature selection, and cascaded neural network. The feature selection is used to remove the irrelevant and redundant inputs. The forecast engine is composed of three cascaded neural network (CNN) structure. This cascaded structure can be efficiently extract input/output mapping function of the nonlinear electricity load data. Adjustable parameters of the intelligent feature selection and CNN is fine-tuned by a kind of cross-validation technique. The proposed STLF is tested on PJM and New York electricity markets. It is concluded from the result, the proposed algorithm is a robust forecast method

  12. Analysis of streaming media systems

    NARCIS (Netherlands)

    Lu, Y.

    2010-01-01

    Multimedia services have been popping up at tremendous speed in recent years. A large number of these multimedia streaming systems are introduced to the consumer market. Internet Service Providers, Telecommunications Operators, Service/Content Providers, and end users are interested in the

  13. Distribution system analysis and automation

    CERN Document Server

    Gers, Juan

    2013-01-01

    A comprehensive guide to techniques that allow engineers to simulate, analyse and optimise power distribution systems which combined with automation, underpin the emerging concept of the "smart grid". This book is supported by theoretical concepts with real-world applications and MATLAB exercises.

  14. Integrated logistic support analysis system

    International Nuclear Information System (INIS)

    Carnicero Iniguez, E.J.; Garcia de la Sen, R.

    1993-01-01

    Integrating logic support into a system results in a large volume of information having to be managed which can only be achieved with the help of computer applications. Both past experience and growing needs in such tasks have led Emperesarios Agrupados to undertake an ambitious development project which is described in this paper. (author)

  15. Safety analysis for complex systems

    Science.gov (United States)

    Onesty, J. P.; Peercy, R. L., Jr.

    1981-01-01

    Operational risk assessment considers hardware, environment, and human factors. Technique starts with division of postulated mission into segments which are further subdivided into separate operational steps. Consequences of steps, nonoccurrence, premature operation, out-of-sequence operation, and inadvertent execution are examined at subevent, event, and phase levels. Hazards are identified and treated individually. Analysis is well suited to application in energy and transportation fields.

  16. Real-Time Observation of Target Search by the CRISPR Surveillance Complex Cascade

    Directory of Open Access Journals (Sweden)

    Chaoyou Xue

    2017-12-01

    Full Text Available CRISPR-Cas systems defend bacteria and archaea against infection by bacteriophage and other threats. The central component of these systems are surveillance complexes that use guide RNAs to bind specific regions of foreign nucleic acids, marking them for destruction. Surveillance complexes must locate targets rapidly to ensure timely immune response, but the mechanism of this search process remains unclear. Here, we used single-molecule FRET to visualize how the type I-E surveillance complex Cascade searches DNA in real time. Cascade rapidly and randomly samples DNA through nonspecific electrostatic contacts, pausing at short PAM recognition sites that may be adjacent to the target. We identify Cascade motifs that are essential for either nonspecific sampling or positioning and readout of the PAM. Our findings provide a comprehensive structural and kinetic model for the Cascade target-search mechanism, revealing how CRISPR surveillance complexes can rapidly search large amounts of genetic material en route to target recognition.

  17. Real time film analysis system MASIS

    International Nuclear Information System (INIS)

    Ajvazyan, V.V.; Badalyan, S.G.; Zalyalov, R.Z.; Klimenko, S.V.

    1990-01-01

    The problems of data organization in the MASIS automated film analysis system are covered. Some elements of the software of the MASIS system are considered: data handling programs providing processing of experimental information, and a program of auxiliary procedures intended for automation of some technological functions of the system. 13 refs.; 1 fig

  18. Receiver System Analysis and Optimization

    Science.gov (United States)

    2013-01-01

    for several devices from the IBM SiGe 8HP process design kit (the manufacturing process used for the MDREX project): bipolar transistor ( BJT ), spiral...of the project. Most significantly, a transistor -level simulation algorithm compatible with the system level simulation algorithm was developed. This... transistor -level simulation program simultaneously and synchronizing them at time intervals. Since the new capability allows the simulation of the entire

  19. Cascade theory in isotopic separation processes

    International Nuclear Information System (INIS)

    Agostini, J.P.

    1994-06-01

    Three main areas are developed within the scope of this work: - the first one is devoted to fundamentals: separative power, value function, ideal cascade and square cascade. Applications to two main cases are carried out, namely: Study of binary isotopic mix, Study of processes with a small enrichment coefficient. - The second one is devoted to cascade coupling -high-flux coupling (more widely used and better known) as well as low-flux coupling are presented and compared to one another. - The third one is an outlook on problems linked to cascade transients. Those problem are somewhat intricate and their interest lies mainly into two areas: economics where the start-up time may have a large influence on the interests paid during the construction and start-up period, military productions where the start-up time has a direct bearing on the production schedule. (author). 50 figs. 3 annexes. 12 refs. 6 tabs

  20. MAP kinase cascades in Arabidopsis innate immunity

    DEFF Research Database (Denmark)

    Rasmussen, Magnus Wohlfahrt; Roux, Milena Edna; Petersen, Morten

    2012-01-01

    Plant mitogen-activated protein kinase (MAPK) cascades generally transduce extracellular stimuli into cellular responses. These stimuli include the perception of pathogen-associated molecular patterns (PAMPs) by host transmembrane pattern recognition receptors which trigger MAPK-dependent innate ...