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Sample records for pat applications propagation

  1. Good Modeling Practice for PAT Applications: Propagation of Input Uncertainty and Sensitivity Analysis

    DEFF Research Database (Denmark)

    Sin, Gürkan; Gernaey, Krist; Eliasson Lantz, Anna

    2009-01-01

    The uncertainty and sensitivity analysis are evaluated for their usefulness as part of the model-building within Process Analytical Technology applications. A mechanistic model describing a batch cultivation of Streptomyces coelicolor for antibiotic production was used as case study. The input...... compared to the large uncertainty observed in the antibiotic and off-gas CO2 predictions. The output uncertainty was observed to be lower during the exponential growth phase, while higher in the stationary and death phases - meaning the model describes some periods better than others. To understand which...... promising for helping to build reliable mechanistic models and to interpret the model outputs properly. These tools make part of good modeling practice, which can contribute to successful PAT applications for increased process understanding, operation and control purposes. © 2009 American Institute...

  2. Chemometrics-based process analytical technology (PAT) tools: applications and adaptation in pharmaceutical and biopharmaceutical industries.

    Science.gov (United States)

    Challa, Shruthi; Potumarthi, Ravichandra

    2013-01-01

    Process analytical technology (PAT) is used to monitor and control critical process parameters in raw materials and in-process products to maintain the critical quality attributes and build quality into the product. Process analytical technology can be successfully implemented in pharmaceutical and biopharmaceutical industries not only to impart quality into the products but also to prevent out-of-specifications and improve the productivity. PAT implementation eliminates the drawbacks of traditional methods which involves excessive sampling and facilitates rapid testing through direct sampling without any destruction of sample. However, to successfully adapt PAT tools into pharmaceutical and biopharmaceutical environment, thorough understanding of the process is needed along with mathematical and statistical tools to analyze large multidimensional spectral data generated by PAT tools. Chemometrics is a chemical discipline which incorporates both statistical and mathematical methods to obtain and analyze relevant information from PAT spectral tools. Applications of commonly used PAT tools in combination with appropriate chemometric method along with their advantages and working principle are discussed. Finally, systematic application of PAT tools in biopharmaceutical environment to control critical process parameters for achieving product quality is diagrammatically represented.

  3. THz spectroscopy: An emerging technology for pharmaceutical development and pharmaceutical Process Analytical Technology (PAT) applications

    Science.gov (United States)

    Wu, Huiquan; Khan, Mansoor

    2012-08-01

    As an emerging technology, THz spectroscopy has gained increasing attention in the pharmaceutical area during the last decade. This attention is due to the fact that (1) it provides a promising alternative approach for in-depth understanding of both intermolecular interaction among pharmaceutical molecules and pharmaceutical product quality attributes; (2) it provides a promising alternative approach for enhanced process understanding of certain pharmaceutical manufacturing processes; and (3) the FDA pharmaceutical quality initiatives, most noticeably, the Process Analytical Technology (PAT) initiative. In this work, the current status and progress made so far on using THz spectroscopy for pharmaceutical development and pharmaceutical PAT applications are reviewed. In the spirit of demonstrating the utility of first principles modeling approach for addressing model validation challenge and reducing unnecessary model validation "burden" for facilitating THz pharmaceutical PAT applications, two scientific case studies based on published THz spectroscopy measurement results are created and discussed. Furthermore, other technical challenges and opportunities associated with adapting THz spectroscopy as a pharmaceutical PAT tool are highlighted.

  4. Teacher's PAT?

    DEFF Research Database (Denmark)

    Vanhuysse, Pieter; Sulitzeanu-Kenan, Raanan

    2009-01-01

    This article aims to contribute to current theoretical debates about political power and agency relationships in education and other public sector settings. In a recent clarion call for a major redirection of political principal-agent theories (PAT), Terry Moe has argued that standard information...... asymmetries ought no longer to be regarded as the sole foundation of bureaucrat power. According to Moe, current theories largely overlook the direct electoral power of agents and their unions (EPA) in voting for their own bureaucratic principals. Therefore, they are biased systematically towards under...

  5. Overview of PAT process analysers applicable in monitoring of film coating unit operations for manufacturing of solid oral dosage forms.

    Science.gov (United States)

    Korasa, Klemen; Vrečer, Franc

    2018-01-01

    Over the last two decades, regulatory agencies have demanded better understanding of pharmaceutical products and processes by implementing new technological approaches, such as process analytical technology (PAT). Process analysers present a key PAT tool, which enables effective process monitoring, and thus improved process control of medicinal product manufacturing. Process analysers applicable in pharmaceutical coating unit operations are comprehensibly described in the present article. The review is focused on monitoring of solid oral dosage forms during film coating in two most commonly used coating systems, i.e. pan and fluid bed coaters. Brief theoretical background and critical overview of process analysers used for real-time or near real-time (in-, on-, at- line) monitoring of critical quality attributes of film coated dosage forms are presented. Besides well recognized spectroscopic methods (NIR and Raman spectroscopy), other techniques, which have made a significant breakthrough in recent years, are discussed (terahertz pulsed imaging (TPI), chord length distribution (CLD) analysis, and image analysis). Last part of the review is dedicated to novel techniques with high potential to become valuable PAT tools in the future (optical coherence tomography (OCT), acoustic emission (AE), microwave resonance (MR), and laser induced breakdown spectroscopy (LIBS)). Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Pump Application as Hydraulic Turbine – Pump as Turbine (PaT)

    OpenAIRE

    Rusovs, D

    2009-01-01

    The paper considers pump operation as hydraulic turbine with purpose to produce mechanical power from liquid flow. The Francis hydraulic turbine was selected for comparison with centrifugal pump in reverse operation. Turbine and centrifugal pump velocity triangles were considered with purpose to evaluate PaT efficiency. Shape of impeller blades for turbine and pumps was analysed. Specific speed calculation is carried out with purpose to obtain similarity in pump and turbine description. For ...

  7. Introducing uncertainty analysis of nucleation and crystal growth models in Process Analytical Technology (PAT) system design of crystallization processes

    DEFF Research Database (Denmark)

    Abdul Samad, Noor Asma Fazli Bin; Sin, Gürkan; Gernaey, Krist

    2013-01-01

    This paper presents the application of uncertainty and sensitivity analysis as part of a systematic modelbased process monitoring and control (PAT) system design framework for crystallization processes. For the uncertainty analysis, the Monte Carlo procedure is used to propagate input uncertainty...

  8. Implementing PAT with Standards

    Science.gov (United States)

    Chandramohan, Laakshmana Sabari; Doolla, Suryanarayana; Khaparde, S. A.

    2016-02-01

    Perform Achieve Trade (PAT) is a market-based incentive mechanism to promote energy efficiency. The purpose of this work is to address the challenges inherent to inconsistent representation of business processes, and interoperability issues in PAT like cap-and-trade mechanisms especially when scaled. Studies by various agencies have highlighted that as the mechanism evolves including more industrial sectors and industries in its ambit, implementation will become more challenging. This paper analyses the major needs of PAT (namely tracking, monitoring, auditing & verifying energy-saving reports, and providing technical support & guidance to stakeholders); and how the aforesaid reasons affect them. Though current technologies can handle these challenges to an extent, standardization activities for implementation have been scanty for PAT and this work attempts to evolve them. The inconsistent modification of business processes, rules, and procedures across stakeholders, and interoperability among heterogeneous systems are addressed. This paper proposes the adoption of specifically two standards into PAT, namely Business Process Model and Notation for maintaining consistency in business process modelling, and Common Information Model (IEC 61970, 61968, 62325 combined) for information exchange. Detailed architecture and organization of these adoptions are reported. The work can be used by PAT implementing agencies, stakeholders, and standardization bodies.

  9. ICAS-PAT: A Software for Design, Analysis and Validation of PAT Systems

    DEFF Research Database (Denmark)

    Singh, Ravendra; Gernaey, Krist; Gani, Rafiqul

    2010-01-01

    end product qualities. In an earlier article, Singh et al. [Singh, R., Gernaey, K. V., Gani, R. (2009). Model-based computer-aided framework for design of process monitoring and analysis systems. Computers & Chemical Engineering, 33, 22–42] proposed the use of a systematic model and data based...... methodology to design appropriate PAT systems. This methodology has now been implemented into a systematic computer-aided framework to develop a software (ICAS-PAT) for design, validation and analysis of PAT systems. Two supporting tools needed by ICAS-PAT have also been developed: a knowledge base...... (consisting of process knowledge as well as knowledge on measurement methods and tools) and a generic model library (consisting of process operational models). Through a tablet manufacturing process example, the application of ICAS-PAT is illustrated, highlighting as well, the main features of the software....

  10. Optical vortex beams: Generation, propagation and applications

    Science.gov (United States)

    Cheng, Wen

    An optical vortex (also known as a screw dislocation or phase singularity) is one type of optical singularity that has a spiral phase wave front around a singularity point where the phase is undefined. Optical vortex beams have a lot of applications in areas such as optical communications, LADAR (laser detection and ranging) system, optical tweezers, optical trapping and laser beam shaping. The concepts of optical vortex beams and methods of generation are briefly discussed. The properties of optical vortex beams propagating through atmospheric turbulence have been studied. A numerical modeling is developed and validated which has been applied to study the high order properties of optical vortex beams propagating though a turbulent atmosphere. The simulation results demonstrate the advantage that vectorial vortex beams may be more stable and maintain beam integrity better when they propagate through turbulent atmosphere. As one important application of optical vortex beams, the laser beam shaping is introduced and studied. We propose and demonstrate a method to generate a 2D flat-top beam profile using the second order full Poincare beams. Its applications in two-dimensional flat-top beam shaping with spatially variant polarization under low numerical aperture focusing have been studied both theoretically and experimentally. A novel compact flat-top beam shaper based on the proposed method has been designed, fabricated and tested. Experimental results show that high quality flat-top profile can be obtained with steep edge roll-off. The tolerance to different input beam sizes of the beam shaper is also verified in the experimental demonstration. The proposed and experimentally verified LC beam shaper has the potential to become a promising candidate for compact and low-cost flat-top beam shaping in areas such as laser processing/machining, lithography and medical treatment.

  11. Role of gibberellins in parthenocarpic fruit development induced by the genetic system pat-3/pat-4 in tomato.

    Science.gov (United States)

    Fos, Mariano; Proaño, Karina; Nuez, Fernando; García-Martínez, José L.

    2001-04-01

    The role of gibberellins (GAs) in the induction of parthenocarpic fruit-set and growth by the pat-3/pat-4 genetic system in tomato (Lycopersicon esculentum Mill.) was investigated using wild type (WT; Cuarenteno) and a near-isogenic line derived from the German line RP75/59 (the source of pat-3/pat-4 parthenocarpy). Unpollinated WT ovaries degenerated but GA3 application induced parthenocarpic fruit growth. On the contrary, parthenocarpic growth of pat-3/pat-4 fruits, which occurs in the absence of pollination and hormone treatment, was not affected by applied GA3. Unpollinated pat-3/pat-4 fruit growth was negated by paclobutrazol, an inhibitor of ent-kaurene oxidase, and this inhibitory effect was negated by GA3. The quantification of the main GAs of the early 13-hydroxylation pathway (GA1, GA8, GA19, GA20, GA29 and GA44) in unpollinated ovaries at 3 developmental stages (flower bud, FB; pre-anthesis, PR; and anthesis, AN), by gas chromatography-selected ion monitoring, showed that the concentration of most of them was higher in pat-3/pat-4 than in WT ovaries at PR and AN stages. The concentration of GA1, suggested previously to be the active GA in tomate, was 2-4 times higher. Unpollinated pat-3/pat-4 ovaries at FB, PR and AN stages also contained relatively high amounts (5-12 ng g-1) of GA3, a GA found at less than 0.5 ng g-1 in WT ovaries. It is concluded that the mutations pat-3/pat-4 may induce natural facultative parthenocarpy capacity in tomato by increasing the concentration of GA1 and GA3 in the ovaries before pollination.

  12. An Application of X-ray Fluorescence as Process Analytical Technology (PAT) to Monitor Particle Coating Processes.

    Science.gov (United States)

    Nakano, Yoshio; Katakuse, Yoshimitsu; Azechi, Yasutaka

    2018-03-30

    An attempt to apply X-ray Fluorescence (XRF) analysis to evaluate small particle coating process as a Process Analytical Technologies (PAT) was made. The XRF analysis was used to monitor coating level in small particle coating process with at-line manner. The small particle coating process usually consists of multiple coating processes. This study was conducted by a simple coating particles prepared by first coating of a model compound (DL-methionine) and second coating by talc on spherical microcrystalline cellulose cores. The particles with two layered coating are enough to demonstrate the small particle coating process. From the result by the small particle coating process, it was found that the XRF signal played different roles, resulting that XRF signals by first coating (layering) and second coating (mask coating) could demonstrate the extent with different mechanisms for the coating process. Furthermore, the particle coating of the different particle size has also been investigated to evaluate size effect of these coating processes. From these results, it was concluded that the XRF could be used as a PAT in monitoring particle coating processes and become powerful tool in pharmaceutical manufacturing.

  13. PAT tools for fermentation processes

    DEFF Research Database (Denmark)

    Gernaey, Krist

    The publication of the Process Analytical Technology (PAT) guidance has been one of the most important milestones for pharmaceutical production during the past ten years. The ideas outlined in the PAT guidance are also applied in other industries, for example the fermentation industry. Process...... knowledge is central in PAT projects. This presentation therefore gives a brief overview of a number of PAT tools for collecting process knowledge on fermentation processes: - On-line sensors, where for example spectroscopic measurements are increasingly applied - Mechanistic models, which can be used...

  14. PAT tools for fermentation processes

    DEFF Research Database (Denmark)

    Gernaey, Krist; Bolic, Andrijana; Svanholm, Bent

    2012-01-01

    The publication of the Process Analytical Technology (PAT) guidance has been one of the most important milestones for pharmaceutical production during the past ten years. The ideas outlined in the PAT guidance are also applied in other industries, for example the fermentation industry. Process...... knowledge is central in PAT projects. This manuscript therefore gives a brief overview of a number of PAT tools for collecting process knowledge on fermentation processes: on-line sensors, mechanistic models and small-scale equipment for high-throughput experimentation. The manuscript ends with a short...

  15. PAT portable appliance testing

    CERN Document Server

    2011-01-01

    The Electricity at Work Regulations 1989 require any electrical system to be constructed, maintained and used in such a manner as to prevent danger. This means that inspection and testing of systems, including portable appliances, is needed in order to determine if maintenance is required.This book explains in clear language what needs to be done and includes expert advice on legislation as well as actual testing. The book contains an appendix providing the electrical fundamentals needed by non-specialists and also has sample questions (with answers) for the C&G 2377 exam that anyone who conducts this work is required to take by law.It is an affordable and handy reference for electricians who administer PAT. It is also an ideal refesher and revision guide for the non-specialist, such as maintenance staff, caretakers and charity shop volunteers who carry out these tasks part-time, alongside their many other duties.Brian Scaddan, I Eng, MIET, is a consultant for and an Honorary Member of City & Guilds. ...

  16. Application of acoustic radiosity methods to noise propagation within buildings

    Science.gov (United States)

    Muehleisen, Ralph T.; Beamer, C. Walter

    2005-09-01

    The prediction of sound pressure levels in rooms from transmitted sound is a difficult problem. The sound energy in the source room incident on the common wall must be accurately predicted. In the receiving room, the propagation of sound from the planar wall source must also be accurately predicted. The radiosity method naturally computes the spatial distribution of sound energy incident on a wall and also naturally predicts the propagation of sound from a planar area source. In this paper, the application of the radiosity method to sound transmission problems is introduced and explained.

  17. Process analytical technology (PAT) tools for the cultivation step in biopharmaceutical production

    NARCIS (Netherlands)

    Streefland, M.; Martens, D.E.; Beuvery, E.C.; Wijffels, R.H.

    2013-01-01

    The process analytical technology (PAT) initiative is now 10 years old. This has resulted in the development of many tools and software packages dedicated to PAT application on pharmaceutical processes. However, most applications are restricted to small molecule drugs, mainly for the relatively

  18. Applications for a general purpose optical beam propagation code

    International Nuclear Information System (INIS)

    Munroe, J.L.; Wallace, N.W.

    1987-01-01

    Real world beam propagation and diffraction problems can rarely be solved by the analytical expressions commonly found in optics and lasers textbooks. These equations are typically valid only for paraxial geometries, for specific boundary conditions (e.g., infinite apertures), or for special assumptions (e.g., at focus). Numerical techniques must be used to solve the equations for the general case. LOTS, a public domain numerical beam propagation software package developed for this purpose, is a widely used and proven tool. The graphical presentation of results combined with a well designed command language make LOTS particularly user-friendly, and the recent implementation of LOTS on the IBM PC/XT family of desktop computes will make this capability available to a much larger group of users. This paper surveys several applications demonstrating the need for such a capability

  19. Adaptive two-regime method: Application to front propagation

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Martin, E-mail: martin.robinson@maths.ox.ac.uk; Erban, Radek, E-mail: erban@maths.ox.ac.uk [Mathematical Institute, University of Oxford, Andrew Wiles Building, Radcliffe Observatory Quarter, Woodstock Road, Oxford OX2 6GG (United Kingdom); Flegg, Mark, E-mail: mark.flegg@monash.edu [School of Mathematical Sciences, Faculty of Science, Monash University Wellington Road, Clayton, Victoria 3800 (Australia)

    2014-03-28

    The Adaptive Two-Regime Method (ATRM) is developed for hybrid (multiscale) stochastic simulation of reaction-diffusion problems. It efficiently couples detailed Brownian dynamics simulations with coarser lattice-based models. The ATRM is a generalization of the previously developed Two-Regime Method [Flegg et al., J. R. Soc., Interface 9, 859 (2012)] to multiscale problems which require a dynamic selection of regions where detailed Brownian dynamics simulation is used. Typical applications include a front propagation or spatio-temporal oscillations. In this paper, the ATRM is used for an in-depth study of front propagation in a stochastic reaction-diffusion system which has its mean-field model given in terms of the Fisher equation [R. Fisher, Ann. Eugen. 7, 355 (1937)]. It exhibits a travelling reaction front which is sensitive to stochastic fluctuations at the leading edge of the wavefront. Previous studies into stochastic effects on the Fisher wave propagation speed have focused on lattice-based models, but there has been limited progress using off-lattice (Brownian dynamics) models, which suffer due to their high computational cost, particularly at the high molecular numbers that are necessary to approach the Fisher mean-field model. By modelling only the wavefront itself with the off-lattice model, it is shown that the ATRM leads to the same Fisher wave results as purely off-lattice models, but at a fraction of the computational cost. The error analysis of the ATRM is also presented for a morphogen gradient model.

  20. Multivariate PAT solutions for biopharmaceutical cultivation: current progress and limitations

    NARCIS (Netherlands)

    Mercier, S.M.; Diepenbroek, B.; Wijffels, R.H.; Streefland, M.

    2014-01-01

    Increasingly elaborate and voluminous datasets are generated by the (bio)pharmaceutical industry and are a major challenge for application of PAT and QbD principles. Multivariate data analysis (MVDA) is required to delineate relevant process information from large multi-factorial and multi-collinear

  1. Introducing uncertainty analysis of nucleation and crystal growth models in Process Analytical Technology (PAT) system design of crystallization processes.

    Science.gov (United States)

    Samad, Noor Asma Fazli Abdul; Sin, Gürkan; Gernaey, Krist V; Gani, Rafiqul

    2013-11-01

    This paper presents the application of uncertainty and sensitivity analysis as part of a systematic model-based process monitoring and control (PAT) system design framework for crystallization processes. For the uncertainty analysis, the Monte Carlo procedure is used to propagate input uncertainty, while for sensitivity analysis, global methods including the standardized regression coefficients (SRC) and Morris screening are used to identify the most significant parameters. The potassium dihydrogen phosphate (KDP) crystallization process is used as a case study, both in open-loop and closed-loop operation. In the uncertainty analysis, the impact on the predicted output of uncertain parameters related to the nucleation and the crystal growth model has been investigated for both a one- and two-dimensional crystal size distribution (CSD). The open-loop results show that the input uncertainties lead to significant uncertainties on the CSD, with appearance of a secondary peak due to secondary nucleation for both cases. The sensitivity analysis indicated that the most important parameters affecting the CSDs are nucleation order and growth order constants. In the proposed PAT system design (closed-loop), the target CSD variability was successfully reduced compared to the open-loop case, also when considering uncertainty in nucleation and crystal growth model parameters. The latter forms a strong indication of the robustness of the proposed PAT system design in achieving the target CSD and encourages its transfer to full-scale implementation. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Implementations of back propagation algorithm in ecosystems applications

    Science.gov (United States)

    Ali, Khalda F.; Sulaiman, Riza; Elamir, Amir Mohamed

    2015-05-01

    Artificial Neural Networks (ANNs) have been applied to an increasing number of real world problems of considerable complexity. Their most important advantage is in solving problems which are too complex for conventional technologies, that do not have an algorithmic solutions or their algorithmic Solutions is too complex to be found. In general, because of their abstraction from the biological brain, ANNs are developed from concept that evolved in the late twentieth century neuro-physiological experiments on the cells of the human brain to overcome the perceived inadequacies with conventional ecological data analysis methods. ANNs have gained increasing attention in ecosystems applications, because of ANN's capacity to detect patterns in data through non-linear relationships, this characteristic confers them a superior predictive ability. In this research, ANNs is applied in an ecological system analysis. The neural networks use the well known Back Propagation (BP) Algorithm with the Delta Rule for adaptation of the system. The Back Propagation (BP) training Algorithm is an effective analytical method for adaptation of the ecosystems applications, the main reason because of their capacity to detect patterns in data through non-linear relationships. This characteristic confers them a superior predicting ability. The BP algorithm uses supervised learning, which means that we provide the algorithm with examples of the inputs and outputs we want the network to compute, and then the error is calculated. The idea of the back propagation algorithm is to reduce this error, until the ANNs learns the training data. The training begins with random weights, and the goal is to adjust them so that the error will be minimal. This research evaluated the use of artificial neural networks (ANNs) techniques in an ecological system analysis and modeling. The experimental results from this research demonstrate that an artificial neural network system can be trained to act as an expert

  3. Application of propagation calculations in air quality control

    International Nuclear Information System (INIS)

    Kuelske, S.

    1993-01-01

    This paper describes the development of a methodics of propagation calculation since the foundation of the 'Landesanstalt fuer Immissionsschutz' in 1963, and its practical use in air quality control. In this context, it deals with methods for calculating stack heights and the Gaussian propagation model adopted by the Technical Code on Clean Air, the propagation of flue gas emitted via cooling towers, the propagation of accidentally released substances, odours and automobile emissions, and with flow and propagation calculation for the proximity zone of buildings as well as for meteorological fields with space and time variations and topographically varied terrain. (orig.) [de

  4. Annex 2: performance audit tool PAT

    Energy Technology Data Exchange (ETDEWEB)

    Kaldorf, S.; Gruber, P.

    2000-10-15

    This annex to the report takes a look at experience gained with one of two expert systems used for error-detection and diagnosis in existing buildings. The Performance Audit Tool PAT is based on an expert system for the detection and diagnosis of under-performance. Its aim is to assist the system's operator. It was developed as a stand-alone system which periodically runs a remote detection and diagnosis check. The various types of under-performance that the system can detect are discussed. The first objective of this study was to present the structure of the tool and describe its application to two types of system: a central air-handling unit and individual zones. The second objective was to discuss experience gained with this type of tool.

  5. Velocities in a Centrifugal PAT Operation: Experiments and CFD Analyses

    Directory of Open Access Journals (Sweden)

    Mariana Simão

    2017-12-01

    Full Text Available Velocity profiles originated by a pump as turbine (PAT were measured using an ultrasonic doppler velocimetry (UDV. PAT behavior is influenced by the velocity data. The effect of the rotational speed and the associated flow velocity variations were investigated. This research focuses, particularly, on the velocity profiles achieved for different rotational speeds and discharge values along the impeller since that is where the available hydraulic power is transformed into the mechanical power. Comparisons were made between experimental test results and computational fluid dynamics (CFD simulations. The used CFD model was calibrated and validated using the same conditions as the experimental facility. The numerical simulations showed good approximation with the velocity measurements for different cross-sections along the PAT system. The application of this CFD numerical model and experimental tests contributed to better understanding the system behavior and to reach the best efficiency operating conditions. Improvements in the knowledge about the hydrodynamic flow behavior associated with the velocity triangles contribute to improvements in the PAT concept and operation.

  6. A GLIMPSE OF POSITIVE ACCOUNTING THEORY (PAT

    Directory of Open Access Journals (Sweden)

    Muhammad Rifky Santoso

    2017-11-01

    Full Text Available Positive accounting theory (PAT has been more developed than normative accounting theory in this era. The development of PAT research has discussed about what factors influenced management to report earnings. By using literature reviews, there are many researches in discussing the external factors to influence management to report earnings, such as bonuses, the debt equity ratio, political costs, and good governance. The other researches have discussed the association between earnings and stock prices. There are still few discussions about the selfmotivation of the directors or managers why choose a certain accounting method. The difference of environment, types of industry, and timing of financial statement reporting can be a further research. By using theories introduced by Popper, Kuhn, and Lakatos, PAT has elements in these three theories; however, PAT has not been categorized as science.

  7. Process analytical technology (PAT) for biopharmaceuticals

    DEFF Research Database (Denmark)

    Glassey, Jarka; Gernaey, Krist; Clemens, Christoph

    2011-01-01

    Process analytical technology (PAT), the regulatory initiative for building in quality to pharmaceutical manufacturing, has a great potential for improving biopharmaceutical production. The recommended analytical tools for building in quality, multivariate data analysis, mechanistic modeling, novel...

  8. THz Wave Propagation on Strip Lines: Devices, Properties, and Applications

    Directory of Open Access Journals (Sweden)

    Y. Kadoya

    2008-06-01

    Full Text Available We report the propagation characteristics of THz pulses on micro-strip-lines and coplanar strip-lines, in which low permittivity polymer materials are used as the dielectric layer or the substrate. As a result of the low attenuation and small dispersion in the devices, the spectral width up to 3 THz can be achieved even after the 1 mm propagation. Spectroscopic characterizations of liquid or powder specimens are demonstrated using the devices. We also show a possibility of realizing a very low attenuation using a quadrupole mode in three strip coplanar lines on the polymer substrate.

  9. PATs Operating in Water Networks under Unsteady Flow Conditions: Control Valve Manoeuvre and Overspeed Effect

    Directory of Open Access Journals (Sweden)

    Modesto Pérez-Sánchez

    2018-04-01

    Full Text Available The knowledge of transient conditions in water pressurized networks equipped with pump as turbines (PATs is of the utmost importance and necessary for the design and correct implementation of these new renewable solutions. This research characterizes the water hammer phenomenon in the design of PAT systems, emphasizing the transient events that can occur during a normal operation. This is based on project concerns towards a stable and efficient operation associated with the normal dynamic behaviour of flow control valve closure or by the induced overspeed effect. Basic concepts of mathematical modelling, characterization of control valve behaviour, damping effects in the wave propagation and runaway conditions of PATs are currently related to an inadequate design. The precise evaluation of basic operating rules depends upon the system and component type, as well as the required safety level during each operation.

  10. Microwave propagation and remote sensing atmospheric influences with models and applications

    CERN Document Server

    Karmakar, Pranab Kumar

    2011-01-01

    Because prevailing atmospheric/troposcopic conditions greatly influence radio wave propagation above 10 GHz, the unguided propagation of microwaves in the neutral atmosphere can directly impact many vital applications in science and engineering. These include transmission of intelligence, and radar and radiometric applications used to probe the atmosphere, among others. Where most books address either one or the other, Microwave Propagation and Remote Sensing: Atmospheric Influences with Models and Applications melds coverage of these two subjects to help readers develop solutions to the problems they present. This reference offers a brief, elementary account of microwave propagation through the atmosphere and discusses radiometric applications in the microwave band used to characterize and model atmospheric constituents, which is also known as remote sensing. Summarizing the latest research results in the field, as well as radiometric models and measurement methods, this book covers topics including: Free sp...

  11. Propagation and application of waves in the ionosphere.

    Science.gov (United States)

    Yeh, K. C.; Liu, C. H.

    1972-01-01

    This review deals with the propagation of waves, especially radio waves in the ionosphere. In the macroscopic electromagnetic theory, the mathematical structure of wave propagation problems depends entirely on the properties of the dielectric operator in a magnetically nonpermeable medium. These properties can be deduced from general discussions of symmetry and considerations of physical principles. When the medium is specifically the ionosphere, various physical phenomena may occur. Because of a large number of parameters, it is desirable to define a parameter space. A point in the parameter space corresponds to a specific plasma. The parameter space is subdivided into regions whose boundaries correspond to conditions of resonance and cutoff. As the point crosses these boundaries, the refractive index surface transforms continuously.

  12. Wave propagation in layered anisotropic media with application to composites

    CERN Document Server

    Nayfeh, AH

    1995-01-01

    Recent advances in the study of the dynamic behavior of layered materials in general, and laminated fibrous composites in particular, are presented in this book. The need to understand the microstructural behavior of such classes of materials has brought a new challenge to existing analytical tools. This book explores the fundamental question of how mechanical waves propagate and interact with layered anisotropic media. The chapters are organized in a logical sequence depending upon the complexity of the physical model and its mathematical treatment.

  13. Imaging by forward propagating the data: Theory and application

    KAUST Repository

    Zuberi, Akbar

    2013-02-27

    The forward (modelled) wavefield for conventional reverse time migration (RTM) is computed by extrapolating the wavefield from an estimated source wavelet. In the typical case of a smooth subsurface velocity, this wavefield lacks the components, including surface reflections, necessary to image multiples in the observed data. We, instead, introduce the concept of forward propagating the recorded data, including direct arrivals, as part of RTM. We analyse the influence of the main components of the data on the imaging process, which include direct arrivals, primaries and surface-related multiples. In our RTM methodology, this implies correlating the forward extrapolated recorded data wavefield with its reversely extrapolated version prior to applying the zero-lag cross-correlation imaging condition. The interaction of the data components with each other in the cross-correlation process will image primaries and multiples, as well as introduce cross-talk artefact terms. However, some of these artefacts are present in conventional RTM implementation and they tend to be relatively weak. In fact, for the surface seismic experiment, forward propagating the direct arrivals is almost equivalent to forward propagating a source and it tends to contribute the majority of the data imaging energy. In addition, primaries and multiples recorded in the data become multiples of one higher order. Forward propagating the recorded data to recreate the source will relieve us from the requirement of estimating the source function. It will also include near-surface information necessary to improve the image in areas with near-surface complexity. Data from a simple synthetic layered model, as well as the Marmousi model, are used to demonstrate some of these features. © 2013 European Association of Geoscientists & Engineers.

  14. Hindrances to bistable front propagation: application to Wolbachia invasion.

    Science.gov (United States)

    Nadin, Grégoire; Strugarek, Martin; Vauchelet, Nicolas

    2018-05-01

    We study the biological situation when an invading population propagates and replaces an existing population with different characteristics. For instance, this may occur in the presence of a vertically transmitted infection causing a cytoplasmic effect similar to the Allee effect (e.g. Wolbachia in Aedes mosquitoes): the invading dynamics we model is bistable. We aim at quantifying the propagules (what does it take for an invasion to start?) and the invasive power (how far can an invading front go, and what can stop it?). We rigorously show that a heterogeneous environment inducing a strong enough population gradient can stop an invading front, which will converge in this case to a stable front. We characterize the critical population jump, and also prove the existence of unstable fronts above the stable (blocking) fronts. Being above the maximal unstable front enables an invading front to clear the obstacle and propagate further. We are particularly interested in the case of artificial Wolbachia infection, used as a tool to fight arboviruses.

  15. Project Integration Architecture: Inter-Application Propagation of Information

    Science.gov (United States)

    Jones, William Henry

    2005-01-01

    A principal goal of the Project Integration Architecture (PIA) is to facilitate the meaningful inter-application transfer of application-value-added information. Such exchanging applications may be largely unrelated to each other except through their applicability to an overall project; however, the PIA effort recognizes as fundamental the need to make such applications cooperate despite wide disparaties either in the fidelity of the analyses carried out, or even the disciplines of the analysis. This paper discusses the approach and techniques applied and anticipated by the PIA project in treating this need.

  16. Antimatter/HiPAT Support Services

    Science.gov (United States)

    Lewis, Raymond A.

    2001-01-01

    Techniques were developed for trapping normal matter in the High Performance Antiproton Trap (HiPAT). Situations encountered included discharge phenomena, charge exchange and radial diffusion processes. It is important to identify these problems, since they will also limit the performance in trapping antimatter next year.

  17. Signal Propagation Delay as a Barrier to Control Applications in WAN

    DEFF Research Database (Denmark)

    Knudsen, Thomas Phillip; Patel, A.; Pedersen, Jens Myrup

    With the advent in WAN of delay sensitive technical applications, such as remote control, signal propagation delay becomes a major problem. The extent of the problem is analysed by lower bounding the delay in relation to different transmission media. Requirements for reliability and bandwidth are...... are considered. The consequences of this bounding for communication network planning and provisioning are discussed in relation to mitigating the effects of signal propagation delay as a barrier to the penetration of control applications into WAN......With the advent in WAN of delay sensitive technical applications, such as remote control, signal propagation delay becomes a major problem. The extent of the problem is analysed by lower bounding the delay in relation to different transmission media. Requirements for reliability and bandwidth...

  18. PAT-2 (Plutonium Air Transportable Model 2)

    International Nuclear Information System (INIS)

    Anderson, J.

    1981-01-01

    The PAT-2 (Plutonium Air Transportable Model 2) package is designed for the safe transport of plutonium and/or uranium in small quantities, especially as used in international safeguards activities, and especially as transported by air. The PAT-2 package is resistant to severe accidents, including that of a high-speed jet aircraft crash, and is designed to withstand such environments as extreme impact, crushing, puncturing and slashing loads, severe hydrocarbon-fueled fires, and deep underwater immersion, with no escape of contents. The accident environments may be imposed upon the package singly or seqentially. The package meets the requirements of 10 CFR 71 for Fissile Class I packages with a cargo of 15 grams of Pu-239, or other isotopic forms described herein, not to exceed 2 watts of thermal activity. Packaging, operational features, and contents of package, are discussed

  19. Correspondence between sound propagation in discrete and continuous random media with application to forest acoustics.

    Science.gov (United States)

    Ostashev, Vladimir E; Wilson, D Keith; Muhlestein, Michael B; Attenborough, Keith

    2018-02-01

    Although sound propagation in a forest is important in several applications, there are currently no rigorous yet computationally tractable prediction methods. Due to the complexity of sound scattering in a forest, it is natural to formulate the problem stochastically. In this paper, it is demonstrated that the equations for the statistical moments of the sound field propagating in a forest have the same form as those for sound propagation in a turbulent atmosphere if the scattering properties of the two media are expressed in terms of the differential scattering and total cross sections. Using the existing theories for sound propagation in a turbulent atmosphere, this analogy enables the derivation of several results for predicting forest acoustics. In particular, the second-moment parabolic equation is formulated for the spatial correlation function of the sound field propagating above an impedance ground in a forest with micrometeorology. Effective numerical techniques for solving this equation have been developed in atmospheric acoustics. In another example, formulas are obtained that describe the effect of a forest on the interference between the direct and ground-reflected waves. The formulated correspondence between wave propagation in discrete and continuous random media can also be used in other fields of physics.

  20. Light propagation through the eye: numerical considerations and applications to presbylasik surgery analysis

    OpenAIRE

    Espinosa Tomás, Julián; Pérez Rodríguez, Jorge; Mas Candela, David; Illueca Contri, Carlos; Sala Pomares, Esperanza; Ortiz Márquez, Dolores; Alió y Sanz, Jorge L.

    2006-01-01

    Trabajo presentado en el 3rd European Meeting in Physiological Optics, London, September 7-9, 2006. Transmittance evaluation of cornea. Transmittance evaluation of crystalline lens. Wave propagation (angular spectrum) up to the plane of interest. Applications to presbylasik surgery analysis.

  1. Pit-a-Pat: A Smart Electrocardiogram System for Detecting Arrhythmia.

    Science.gov (United States)

    Park, Juyoung; Lee, Kuyeon; Kang, Kyungtae

    2015-10-01

    Electrocardiogram (ECG) telemonitoring is one of the most promising applications of medical telemetry. However, previous approaches to ECG telemonitoring have largely relied on public databases of ECG results. In this article we propose a smart ECG system called Pit-a-Pat, which extracts features from ECG signals and detects arrhythmia. It is designed to run on an Android™ (Google, Mountain View, CA) device, without requiring modifications to other software. We implemented the Pit-a-Pat system using a commercial ECG device, and the experimental results demonstrate the effectiveness and accuracy of Pit-a-Pat for monitoring the ECG signal and analyzing the cardiac activity of a mobile patient. The proposed system allows monitoring of cardiac activity with automatic analysis, thereby providing a convenient, inexpensive, and ubiquitous adjunct to personal healthcare.

  2. Manipulations of Wavefront Propagation: Useful Methods and Applications for Interferometric Measurements and Scanning

    Directory of Open Access Journals (Sweden)

    Avi Karsenty

    2017-01-01

    Full Text Available Phase measurements obtained by high-coherence interferometry are restricted by the 2π ambiguity, to height differences smaller than λ/2. A further restriction in most interferometric systems is for focusing the system on the measured object. We present two methods that overcome these restrictions. In the first method, different segments of a measured wavefront are digitally propagated and focused locally after measurement. The divergent distances, by which the diverse segments of the wavefront are propagated in order to achieve a focused image, provide enough information so as to resolve the 2π ambiguity. The second method employs an interferogram obtained by a spectrum constituting a small number of wavelengths. The magnitude of the interferogram’s modulations is utilized to resolve the 2π ambiguity. Such methods of wavefront propagation enable several applications such as focusing and resolving the 2π ambiguity, as described in the article.

  3. PAT-1 safety analysis report addendum.

    Energy Technology Data Exchange (ETDEWEB)

    Weiner, Ruth F.; Schmale, David T.; Kalan, Robert J.; Akin, Lili A.; Miller, David Russell; Knorovsky, Gerald Albert; Yoshimura, Richard Hiroyuki; Lopez, Carlos; Harding, David Cameron; Jones, Perry L.; Morrow, Charles W.

    2010-09-01

    The Plutonium Air Transportable Package, Model PAT-1, is certified under Title 10, Code of Federal Regulations Part 71 by the U.S. Nuclear Regulatory Commission (NRC) per Certificate of Compliance (CoC) USA/0361B(U)F-96 (currently Revision 9). The purpose of this SAR Addendum is to incorporate plutonium (Pu) metal as a new payload for the PAT-1 package. The Pu metal is packed in an inner container (designated the T-Ampoule) that replaces the PC-1 inner container. The documentation and results from analysis contained in this addendum demonstrate that the replacement of the PC-1 and associated packaging material with the T-Ampoule and associated packaging with the addition of the plutonium metal content are not significant with respect to the design, operating characteristics, or safe performance of the containment system and prevention of criticality when the package is subjected to the tests specified in 10 CFR 71.71, 71.73 and 71.74.

  4. Efficient techniques for wave-based sound propagation in interactive applications

    Science.gov (United States)

    Mehra, Ravish

    Sound propagation techniques model the effect of the environment on sound waves and predict their behavior from point of emission at the source to the final point of arrival at the listener. Sound is a pressure wave produced by mechanical vibration of a surface that propagates through a medium such as air or water, and the problem of sound propagation can be formulated mathematically as a second-order partial differential equation called the wave equation. Accurate techniques based on solving the wave equation, also called the wave-based techniques, are too expensive computationally and memory-wise. Therefore, these techniques face many challenges in terms of their applicability in interactive applications including sound propagation in large environments, time-varying source and listener directivity, and high simulation cost for mid-frequencies. In this dissertation, we propose a set of efficient wave-based sound propagation techniques that solve these three challenges and enable the use of wave-based sound propagation in interactive applications. Firstly, we propose a novel equivalent source technique for interactive wave-based sound propagation in large scenes spanning hundreds of meters. It is based on the equivalent source theory used for solving radiation and scattering problems in acoustics and electromagnetics. Instead of using a volumetric or surface-based approach, this technique takes an object-centric approach to sound propagation. The proposed equivalent source technique generates realistic acoustic effects and takes orders of magnitude less runtime memory compared to prior wave-based techniques. Secondly, we present an efficient framework for handling time-varying source and listener directivity for interactive wave-based sound propagation. The source directivity is represented as a linear combination of elementary spherical harmonic sources. This spherical harmonic-based representation of source directivity can support analytical, data

  5. Understanding the Physical Optics Phenomena by Using a Digital Application for Light Propagation

    International Nuclear Information System (INIS)

    Sierra-Sosa, Daniel-Esteban; Angel-Toro, Luciano

    2011-01-01

    Understanding the light propagation on the basis of the Huygens-Fresnel principle stands for a fundamental factor for deeper comprehension of different physical optics related phenomena like diffraction, self-imaging, image formation, Fourier analysis and spatial filtering. This constitutes the physical approach of the Fourier optics whose principles and applications have been developed since the 1950's. Both for analytical and digital applications purposes, light propagation can be formulated in terms of the Fresnel Integral Transform. In this work, a digital optics application based on the implementation of the Discrete Fresnel Transform (DFT), and addressed to serve as a tool for applications in didactics of optics is presented. This tool allows, at a basic and intermediate learning level, exercising with the identification of basic phenomena, and observing changes associated with modifications of physical parameters. This is achieved by using a friendly graphic user interface (GUI). It also assists the user in the development of his capacity for abstracting and predicting the characteristics of more complicated phenomena. At an upper level of learning, the application could be used to favor a deeper comprehension of involved physics and models, and experimenting with new models and configurations. To achieve this, two characteristics of the didactic tool were taken into account when designing it. First, all physical operations, ranging from simple diffraction experiments to digital holography and interferometry, were developed on the basis of the more fundamental concept of light propagation. Second, the algorithm was conceived to be easily upgradable due its modular architecture based in MATLAB (registered) software environment. Typical results are presented and briefly discussed in connection with didactics of optics.

  6. Understanding the Physical Optics Phenomena by Using a Digital Application for Light Propagation

    Energy Technology Data Exchange (ETDEWEB)

    Sierra-Sosa, Daniel-Esteban; Angel-Toro, Luciano, E-mail: dsierras@eafit.edu.co, E-mail: langel@eafit.edu.co [Grupo de Optica Aplicada, Universidad EAFIT, 1 Medellin (Colombia)

    2011-01-01

    Understanding the light propagation on the basis of the Huygens-Fresnel principle stands for a fundamental factor for deeper comprehension of different physical optics related phenomena like diffraction, self-imaging, image formation, Fourier analysis and spatial filtering. This constitutes the physical approach of the Fourier optics whose principles and applications have been developed since the 1950's. Both for analytical and digital applications purposes, light propagation can be formulated in terms of the Fresnel Integral Transform. In this work, a digital optics application based on the implementation of the Discrete Fresnel Transform (DFT), and addressed to serve as a tool for applications in didactics of optics is presented. This tool allows, at a basic and intermediate learning level, exercising with the identification of basic phenomena, and observing changes associated with modifications of physical parameters. This is achieved by using a friendly graphic user interface (GUI). It also assists the user in the development of his capacity for abstracting and predicting the characteristics of more complicated phenomena. At an upper level of learning, the application could be used to favor a deeper comprehension of involved physics and models, and experimenting with new models and configurations. To achieve this, two characteristics of the didactic tool were taken into account when designing it. First, all physical operations, ranging from simple diffraction experiments to digital holography and interferometry, were developed on the basis of the more fundamental concept of light propagation. Second, the algorithm was conceived to be easily upgradable due its modular architecture based in MATLAB (registered) software environment. Typical results are presented and briefly discussed in connection with didactics of optics.

  7. Understanding the Physical Optics Phenomena by Using a Digital Application for Light Propagation

    Science.gov (United States)

    Sierra-Sosa, Daniel-Esteban; Ángel-Toro, Luciano

    2011-01-01

    Understanding the light propagation on the basis of the Huygens-Fresnel principle stands for a fundamental factor for deeper comprehension of different physical optics related phenomena like diffraction, self-imaging, image formation, Fourier analysis and spatial filtering. This constitutes the physical approach of the Fourier optics whose principles and applications have been developed since the 1950's. Both for analytical and digital applications purposes, light propagation can be formulated in terms of the Fresnel Integral Transform. In this work, a digital optics application based on the implementation of the Discrete Fresnel Transform (DFT), and addressed to serve as a tool for applications in didactics of optics is presented. This tool allows, at a basic and intermediate learning level, exercising with the identification of basic phenomena, and observing changes associated with modifications of physical parameters. This is achieved by using a friendly graphic user interface (GUI). It also assists the user in the development of his capacity for abstracting and predicting the characteristics of more complicated phenomena. At an upper level of learning, the application could be used to favor a deeper comprehension of involved physics and models, and experimenting with new models and configurations. To achieve this, two characteristics of the didactic tool were taken into account when designing it. First, all physical operations, ranging from simple diffraction experiments to digital holography and interferometry, were developed on the basis of the more fundamental concept of light propagation. Second, the algorithm was conceived to be easily upgradable due its modular architecture based in MATLAB® software environment. Typical results are presented and briefly discussed in connection with didactics of optics.

  8. Applicability assessment of plug weld to ITER vacuum vessel by crack propagation analysis

    International Nuclear Information System (INIS)

    Ohmori, Junji; Nakahira, Masataka; Takeda, Nobukazu; Shibanuma, Kiyoshi; Sago, Hiromi; Onozuka, Masanori

    2006-03-01

    In order to improve the fabricability of the vacuum vessel (VV) of International Thermonuclear Experimental Reactor (ITER), applicability of plug weld between VV outer shell and stiffening ribs/blanket support housings has been assessed using crack propagation analysis for the plug weld. The ITER VV is a double-wall structure of inner and outer shells with ribs and housings between the shells. For the fabrication of VV, ribs and housings are welded to outer shell after welding to inner shell. A lot of weld grooves should be adjusted for welding outer shell. The plug weld is that outer shells with slit at the weld region are set on ribs/housings then outer shells are welded to them by filling the slits with weld metal. The plug weld can allow larger tolerance of weld groove gap than ordinary butt weld. However, un-welded lengths parallel to outer sell surface remain in the plug weld region. It is necessary to evaluate the allowable un-welded length to apply the plug weld to ITER VV fabrication. For the assessment, the allowable un-welded lengths have been calculated by crack propagation analyses for load conditions, conservatively assuming the un-welded region is a crack. In the analyses, firstly allowable crack lengths are calculated from the stresses of the weld region. Then assuming initial crack length, crack propagation is calculated during operation period. Allowable initial crack lengths are determined on the condition that the propagated cracks should not exceed the allowable crack lengths. The analyses have been carried out for typical inboard straight region and inboard upper curved region with the maximum housing stress. The allowable initial cracks of ribs are estimated to be 8.8mm and 38mm for the rib and the housing, respectively, considering inspection error of 4.4mm. Plug weld between outer shell and ribs/housings could be applicable. (author)

  9. On advanced variational formulation of the method of lines and its application to the wave propagation problems

    CSIR Research Space (South Africa)

    Shatalov, M

    2012-09-01

    Full Text Available are transformed into systems of ordinary differential equations with initial conditions. This reduction is obtained by means of application of particular finite difference schemes to the spatial derivatives. Many of the wave propagation problems describing...

  10. The generalized Laguerre polynomials, the associated Bessel functions and application to propagation problems

    International Nuclear Information System (INIS)

    Dattoli, G.; Torre, A.; Mancho, A.M.

    2000-01-01

    The theory of generalized Bessel functions has found significant applications in the analysis of radiation phenomena, associated with charges moving in magnetic devices. In this paper we exploit the monomiality principle to discuss the theory of two-variable Laguerre polynomials and introduce the associated Laguerre-Bessel functions. We study their properties (addition and multiplication theorems, generating function, recurrence relations and so on) and discuss the link with the ordinary case. The usefulness of the obtained results to treat problems relevant to the paraxial propagation of electromagnetic waves is also discussed.

  11. Introductory Applications of Partial Differential Equations With Emphasis on Wave Propagation and Diffusion

    CERN Document Server

    Lamb, George L

    1995-01-01

    INTRODUCTORY APPLICATIONS OF PARTIAL DIFFERENTIAL EQUATIONS. With Emphasis on Wave Propagation and Diffusion. This is the ideal text for students and professionals who have some familiarity with partial differential equations, and who now wish to consolidate and expand their knowledge. Unlike most other texts on this topic, it interweaves prior knowledge of mathematics and physics, especially heat conduction and wave motion, into a presentation that demonstrates their interdependence. The result is a superb teaching text that reinforces the reader's understanding of both mathematics and physic

  12. Toward Higher QA: From Parametric Release of Sterile Parenteral Products to PAT for Other Pharmaceutical Dosage Forms.

    Science.gov (United States)

    Hock, Sia Chong; Constance, Neo Xue Rui; Wah, Chan Lai

    2012-01-01

    Pharmaceutical products are generally subjected to end-product batch testing as a means of quality control. Due to the inherent limitations of conventional batch testing, this is not the most ideal approach for determining the pharmaceutical quality of the finished dosage form. In the case of terminally sterilized parenteral products, the limitations of conventional batch testing have been successfully addressed with the application of parametric release (the release of a product based on control of process parameters instead of batch sterility testing at the end of the manufacturing process). Consequently, there has been an increasing interest in applying parametric release to other pharmaceutical dosage forms, beyond terminally sterilized parenteral products. For parametric release to be possible, manufacturers must be capable of designing quality into the product, monitoring the manufacturing processes, and controlling the quality of intermediates and finished products in real-time. Process analytical technology (PAT) has been thought to be capable of contributing to these prerequisites. It is believed that the appropriate use of PAT tools can eventually lead to the possibility of real-time release of other pharmaceutical dosage forms, by-passing the need for end-product batch testing. Hence, this literature review attempts to present the basic principles of PAT, introduce the various PAT tools that are currently available, present their recent applications to pharmaceutical processing, and explain the potential benefits that PAT can bring to conventional ways of processing and quality assurance of pharmaceutical products. Last but not least, current regulations governing the use of PAT and the manufacturing challenges associated with PAT implementation are also discussed. Pharmaceutical products are generally subjected to end-product batch testing as a means of quality control. Due to the inherent limitations of conventional batch testing, this is not the most

  13. Analysis of the quench propagation along Nb$_{3}$Sn Rutherford cables with the THELMA code. Part II: application to the quench longitudinal propagation

    CERN Document Server

    Manfreda, G.; Bajas, H.; Perez, J.C.

    2016-01-01

    To improve the technology of the new generation of accelerator magnets, prototypes are being manufactured and tested in several laboratories. In parallel, many numerical analyses are being carried out to predict the magnets behaviour and interpret the experimental results. This paper focuses on the quench propagation velocity, which is a crucial parameter as regards the energy dissipation along the magnet conductor. The THELMA code, originally developed for cable-in-conduit conductors for fusion magnets, has been used to study such quench propagation. To this purpose, new code modules have been added to describe the Rutherford cable geometry, the material non-linear thermal properties and to describe the thermal conduction problem in transient regime. THELMA can describe the Rutherford cable at the strand level, modelling both the electrical and thermal contact resistances between strands and enabling the analysis of the effects of local hot spots and quench heaters. This paper describes the model application...

  14. Comparison between different uncertainty propagation methods in multivariate analysis: An application in the bivariate case

    International Nuclear Information System (INIS)

    Mullor, R.; Sanchez, A.; Martorell, S.; Martinez-Alzamora, N.

    2011-01-01

    Safety related systems performance optimization is classically based on quantifying the effects that testing and maintenance activities have on reliability and cost (R+C). However, R+C quantification is often incomplete in the sense that important uncertainties may not be considered. An important number of studies have been published in the last decade in the field of R+C based optimization considering uncertainties. They have demonstrated that inclusion of uncertainties in the optimization brings the decision maker insights concerning how uncertain the R+C results are and how this uncertainty does matter as it can result in differences in the outcome of the decision making process. Several methods of uncertainty propagation based on the theory of tolerance regions have been proposed in the literature depending on the particular characteristics of the variables in the output and their relations. In this context, the objective of this paper focuses on the application of non-parametric and parametric methods to analyze uncertainty propagation, which will be implemented on a multi-objective optimization problem where reliability and cost act as decision criteria and maintenance intervals act as decision variables. Finally, a comparison of results of these applications and the conclusions obtained are presented.

  15. Illumination of interior spaces by bended hollow light guides: Application of the theoretical light propagation method

    Energy Technology Data Exchange (ETDEWEB)

    Darula, Stanislav; Kocifaj, Miroslav; Kittler, Richard [ICA, Slovak Academy of Sciences, Bratislava (Slovakia); Kundracik, Frantisek [Department of Experimental Physics, FMPI, Comenius University, Bratislava (Slovakia)

    2010-12-15

    To ensure comfort and healthy conditions in interior spaces the thermal, acoustics and daylight factors of the environment have to be considered in the building design. Due to effective energy performance in buildings the new technology and applications also in daylight engineering are sought such as tubular light guides. These allow the transport of natural light into the building core reducing energy consumption. A lot of installations with various geometrical and optical properties can be applied in real buildings. The simplest set of tubular light guide consists of a transparent cupola, direct tube with high reflected inner surface and a ceiling cover or diffuser redistributing light into the interior. Such vertical tubular guide is often used on flat roofs. When the roof construction is inclined a bend in the light guide system has to be installed. In this case the cupola is set on the sloped roof which collects sunlight and skylight from the seen part of the sky hemisphere as well as that reflected from the ground and opposite facades. In comparison with the vertical tube some additional light losses and distortions of the propagated light have to be expected in bended tubular light guides. Recently the theoretical model of light propagation was already published and its applications are presented in this study solving illuminance distributions on the ceiling cover interface and further illuminance distribution on the working plane in the interior. (author)

  16. Comparison between different uncertainty propagation methods in multivariate analysis: An application in the bivariate case

    Energy Technology Data Exchange (ETDEWEB)

    Mullor, R. [Dpto. Estadistica e Investigacion Operativa, Universidad Alicante (Spain); Sanchez, A., E-mail: aisanche@eio.upv.e [Dpto. Estadistica e Investigacion Operativa Aplicadas y Calidad, Universidad Politecnica Valencia, Camino de Vera s/n 46022 (Spain); Martorell, S. [Dpto. Ingenieria Quimica y Nuclear, Universidad Politecnica Valencia (Spain); Martinez-Alzamora, N. [Dpto. Estadistica e Investigacion Operativa Aplicadas y Calidad, Universidad Politecnica Valencia, Camino de Vera s/n 46022 (Spain)

    2011-06-15

    Safety related systems performance optimization is classically based on quantifying the effects that testing and maintenance activities have on reliability and cost (R+C). However, R+C quantification is often incomplete in the sense that important uncertainties may not be considered. An important number of studies have been published in the last decade in the field of R+C based optimization considering uncertainties. They have demonstrated that inclusion of uncertainties in the optimization brings the decision maker insights concerning how uncertain the R+C results are and how this uncertainty does matter as it can result in differences in the outcome of the decision making process. Several methods of uncertainty propagation based on the theory of tolerance regions have been proposed in the literature depending on the particular characteristics of the variables in the output and their relations. In this context, the objective of this paper focuses on the application of non-parametric and parametric methods to analyze uncertainty propagation, which will be implemented on a multi-objective optimization problem where reliability and cost act as decision criteria and maintenance intervals act as decision variables. Finally, a comparison of results of these applications and the conclusions obtained are presented.

  17. Part two: Error propagation

    International Nuclear Information System (INIS)

    Picard, R.R.

    1989-01-01

    Topics covered in this chapter include a discussion of exact results as related to nuclear materials management and accounting in nuclear facilities; propagation of error for a single measured value; propagation of error for several measured values; error propagation for materials balances; and an application of error propagation to an example of uranium hexafluoride conversion process

  18. Cryopreservation techniques and their application in vegetatively propagated crop plants in Finland

    Directory of Open Access Journals (Sweden)

    A. NUKARI

    2008-12-01

    Full Text Available Cryopreservation protocols have been introduced as techniques for germplasm preservation of vegetatively propagated horticultural and staple food crops. In Finland, cryopreservation has been studied since 1990’s, beginning with cryopreservation of forest tree breeding material and since 2004 on cryopreservation of genetic resources of horticultural plants and potato. Priority was given to cryopreservation of raspberry (Rubus ideaus L., strawberry (Fragaria x ananassa Duch. and potato (Solanum tuberosum L. and the possibility to use cryotherapy in eradication of raspberry bushy dwarf virus (RBDV from in vitro cultures were studied on raspberry. Modified droplet vitrification cryopreservation protocols were designed for raspberry and strawberry and cryotherapy combined with thermotherapy was proven to be a successful application to eliminate RBDV from infected raspberries. Cryotherapy method can be applied for a large scale elimination of viruses from plant germplasm and from candidate nuclear stock in a certified plant production scheme. Routine use of cryotechniques in germplasm preservation of vegetatively propagated horticultural plants was started. Besides for long term germplasm preservation, cryopreservation techniques can be applied also for maintenance of mother stocks in certified plant production schemes and in commercial plant production. Cryopreservation of potato shoot tips needs additional detailed research to obtain sufficient recovery and regrowth rates.;

  19. Parallel Reservoir Simulations with Sparse Grid Techniques and Applications to Wormhole Propagation

    KAUST Repository

    Wu, Yuanqing

    2015-09-08

    In this work, two topics of reservoir simulations are discussed. The first topic is the two-phase compositional flow simulation in hydrocarbon reservoir. The major obstacle that impedes the applicability of the simulation code is the long run time of the simulation procedure, and thus speeding up the simulation code is necessary. Two means are demonstrated to address the problem: parallelism in physical space and the application of sparse grids in parameter space. The parallel code can gain satisfactory scalability, and the sparse grids can remove the bottleneck of flash calculations. Instead of carrying out the flash calculation in each time step of the simulation, a sparse grid approximation of all possible results of the flash calculation is generated before the simulation. Then the constructed surrogate model is evaluated to approximate the flash calculation results during the simulation. The second topic is the wormhole propagation simulation in carbonate reservoir. In this work, different from the traditional simulation technique relying on the Darcy framework, we propose a new framework called Darcy-Brinkman-Forchheimer framework to simulate wormhole propagation. Furthermore, to process the large quantity of cells in the simulation grid and shorten the long simulation time of the traditional serial code, standard domain-based parallelism is employed, using the Hypre multigrid library. In addition to that, a new technique called “experimenting field approach” to set coefficients in the model equations is introduced. In the 2D dissolution experiments, different configurations of wormholes and a series of properties simulated by both frameworks are compared. We conclude that the numerical results of the DBF framework are more like wormholes and more stable than the Darcy framework, which is a demonstration of the advantages of the DBF framework. The scalability of the parallel code is also evaluated, and good scalability can be achieved. Finally, a mixed

  20. Structure of PatF from Prochloron didemni

    International Nuclear Information System (INIS)

    Bent, Andrew F.; Koehnke, Jesko; Houssen, Wael E.; Smith, Margaret C. M.; Jaspars, Marcel; Naismith, James H.

    2013-01-01

    The X-ray crystal structure of PatF from P. didemni was solved by the single-wavelength anomalous diffraction method to a resolution of 2.13 Å. Patellamides are macrocyclic peptides with potent biological effects and are a subset of the cyanobactins. Cyanobactins are natural products that are produced by a series of enzymatic transformations and a common modification is the addition of a prenyl group. Puzzlingly, the pathway for patellamides in Prochloron didemni contains a gene, patF, with homology to prenylases, but patellamides are not themselves prenylated. The structure of the protein PatF was cloned, expressed, purified and determined. Prenylase activity could not be demonstrated for the protein, and examination of the structure revealed changes in side-chain identity at the active site. It is suggested that these changes have inactivated the protein. Attempts to mutate these residues led to unfolded protein

  1. Source estimation for propagation processes on complex networks with an application to delays in public transportation systems

    NARCIS (Netherlands)

    Manitz, J. (Juliane); Harbering, J. (Jonas); M.E. Schmidt (Marie); T. Kneib (Thomas); A. Schöbel (Anita)

    2017-01-01

    textabstractThe correct identification of the source of a propagation process is crucial in many research fields. As a specific application, we consider source estimation of delays in public transportation networks. We propose two approaches: an effective distance median and a backtracking method.

  2. Numerical modelling of fire propagation: principles and applications at Electricite de France

    International Nuclear Information System (INIS)

    Rongere, F.X.; Gibault, J.

    1994-05-01

    Electricite de France, wishing to limit the accidental unavailability of its nuclear plants and to ensure their safety rigorously takes particular care to reduce the risk of fire. In this context, the Heat Transfer and Aerodynamics Branch of the Research and Development Division has been in charge of the design of numerical tools to simulate the fire propagation in buildings since 1985. Its program is articulated towards three axes which include : the development of the MAGIC software program, the characterization of the combustibles present in power plants, the development of methods for the use of the computer codes in the design of plants. This paper gives on overview of the activity in progress in this research fields. It illustrates also the applications performed and anticipated at Electricite de France of the numerical simulation in fire safety design. We discuss at the end of it the limitations and the development factors of these tool use. One of the later is the association of MAGIC software and the FIVE method. (authors). 15 refs., 10 figs., 2 tabs

  3. Application of radiation induced mutations in the improvement of vegetatively propagated crops

    International Nuclear Information System (INIS)

    Mohan Jain, S.

    2009-01-01

    Full text: The NOBEL PEACE PRIZE, 2005, award to the International Atomic Energy Agency (IAEA) is a recognition to the contributions of nuclear technique applications, in a tough face off with plant genetic engineering, in sustainable food production, improvement of nutrition balance, and food security. Nuclear technology is effective in generating genetic variability, selection of useful mutants and multiplication in large numbers. A wide range of mutants of various vegetatively propagated crops have been isolated (www.iaea.org). In vitro plant regeneration is very much genotypic dependent, type of explants; culture medium, plant growth regulators etc. Somatic embryogenesis is an ideal system for the selection and multiplication of mutants and also would save time to dissociate chimeras. The role of molecular tools has become very crucial in understanding the molecular basis of differentiation and genetic variability; gene identification, isolation, and transfer. The new gene discovery with reverse and forward genetics will open the way for developing functional genomic plant breeding. There is no opposition from the consumers to consume food products derived from mutants, unlike strong opposition to the consumption of genetically modified (GM) food. Moreover, bio-safety regulations are not applied to mutants, however, strictly adhere to GM food. Tomorrow's agriculture will be under tremendous pressure for feeding the world's population in the face of climatic changes, salt and drought stresses, and biotic stresses; and mutagenesis would be the answer

  4. Gaussian processes with built-in dimensionality reduction: Applications to high-dimensional uncertainty propagation

    International Nuclear Information System (INIS)

    Tripathy, Rohit; Bilionis, Ilias; Gonzalez, Marcial

    2016-01-01

    Uncertainty quantification (UQ) tasks, such as model calibration, uncertainty propagation, and optimization under uncertainty, typically require several thousand evaluations of the underlying computer codes. To cope with the cost of simulations, one replaces the real response surface with a cheap surrogate based, e.g., on polynomial chaos expansions, neural networks, support vector machines, or Gaussian processes (GP). However, the number of simulations required to learn a generic multivariate response grows exponentially as the input dimension increases. This curse of dimensionality can only be addressed, if the response exhibits some special structure that can be discovered and exploited. A wide range of physical responses exhibit a special structure known as an active subspace (AS). An AS is a linear manifold of the stochastic space characterized by maximal response variation. The idea is that one should first identify this low dimensional manifold, project the high-dimensional input onto it, and then link the projection to the output. If the dimensionality of the AS is low enough, then learning the link function is a much easier problem than the original problem of learning a high-dimensional function. The classic approach to discovering the AS requires gradient information, a fact that severely limits its applicability. Furthermore, and partly because of its reliance to gradients, it is not able to handle noisy observations. The latter is an essential trait if one wants to be able to propagate uncertainty through stochastic simulators, e.g., through molecular dynamics codes. In this work, we develop a probabilistic version of AS which is gradient-free and robust to observational noise. Our approach relies on a novel Gaussian process regression with built-in dimensionality reduction. In particular, the AS is represented as an orthogonal projection matrix that serves as yet another covariance function hyper-parameter to be estimated from the data. To train the

  5. Gaussian processes with built-in dimensionality reduction: Applications to high-dimensional uncertainty propagation

    Science.gov (United States)

    Tripathy, Rohit; Bilionis, Ilias; Gonzalez, Marcial

    2016-09-01

    Uncertainty quantification (UQ) tasks, such as model calibration, uncertainty propagation, and optimization under uncertainty, typically require several thousand evaluations of the underlying computer codes. To cope with the cost of simulations, one replaces the real response surface with a cheap surrogate based, e.g., on polynomial chaos expansions, neural networks, support vector machines, or Gaussian processes (GP). However, the number of simulations required to learn a generic multivariate response grows exponentially as the input dimension increases. This curse of dimensionality can only be addressed, if the response exhibits some special structure that can be discovered and exploited. A wide range of physical responses exhibit a special structure known as an active subspace (AS). An AS is a linear manifold of the stochastic space characterized by maximal response variation. The idea is that one should first identify this low dimensional manifold, project the high-dimensional input onto it, and then link the projection to the output. If the dimensionality of the AS is low enough, then learning the link function is a much easier problem than the original problem of learning a high-dimensional function. The classic approach to discovering the AS requires gradient information, a fact that severely limits its applicability. Furthermore, and partly because of its reliance to gradients, it is not able to handle noisy observations. The latter is an essential trait if one wants to be able to propagate uncertainty through stochastic simulators, e.g., through molecular dynamics codes. In this work, we develop a probabilistic version of AS which is gradient-free and robust to observational noise. Our approach relies on a novel Gaussian process regression with built-in dimensionality reduction. In particular, the AS is represented as an orthogonal projection matrix that serves as yet another covariance function hyper-parameter to be estimated from the data. To train the

  6. Gaussian processes with built-in dimensionality reduction: Applications to high-dimensional uncertainty propagation

    Energy Technology Data Exchange (ETDEWEB)

    Tripathy, Rohit, E-mail: rtripath@purdue.edu; Bilionis, Ilias, E-mail: ibilion@purdue.edu; Gonzalez, Marcial, E-mail: marcial-gonzalez@purdue.edu

    2016-09-15

    Uncertainty quantification (UQ) tasks, such as model calibration, uncertainty propagation, and optimization under uncertainty, typically require several thousand evaluations of the underlying computer codes. To cope with the cost of simulations, one replaces the real response surface with a cheap surrogate based, e.g., on polynomial chaos expansions, neural networks, support vector machines, or Gaussian processes (GP). However, the number of simulations required to learn a generic multivariate response grows exponentially as the input dimension increases. This curse of dimensionality can only be addressed, if the response exhibits some special structure that can be discovered and exploited. A wide range of physical responses exhibit a special structure known as an active subspace (AS). An AS is a linear manifold of the stochastic space characterized by maximal response variation. The idea is that one should first identify this low dimensional manifold, project the high-dimensional input onto it, and then link the projection to the output. If the dimensionality of the AS is low enough, then learning the link function is a much easier problem than the original problem of learning a high-dimensional function. The classic approach to discovering the AS requires gradient information, a fact that severely limits its applicability. Furthermore, and partly because of its reliance to gradients, it is not able to handle noisy observations. The latter is an essential trait if one wants to be able to propagate uncertainty through stochastic simulators, e.g., through molecular dynamics codes. In this work, we develop a probabilistic version of AS which is gradient-free and robust to observational noise. Our approach relies on a novel Gaussian process regression with built-in dimensionality reduction. In particular, the AS is represented as an orthogonal projection matrix that serves as yet another covariance function hyper-parameter to be estimated from the data. To train the

  7. Power Series Expansion of Propagator for Path Integral and Its Applications

    International Nuclear Information System (INIS)

    Ou Yuanjin; Liang Xianting

    2007-01-01

    In this paper we obtain a propagator of path integral for a harmonic oscillator and a driven harmonic oscillator by using the power series expansion. It is shown that our result for the harmonic oscillator is more exact than the previous one obtained with other approximation methods. By using the same method, we obtain a propagator of path integral for the driven harmonic oscillator, which does not have any exact expansion. The more exact propagators may improve the path integral results for these systems.

  8. At-line process analytical technology (PAT) for more efficient scale up of biopharmaceutical microfiltration unit operations.

    Science.gov (United States)

    Watson, Douglas S; Kerchner, Kristi R; Gant, Sean S; Pedersen, Joseph W; Hamburger, James B; Ortigosa, Allison D; Potgieter, Thomas I

    2016-01-01

    Tangential flow microfiltration (MF) is a cost-effective and robust bioprocess separation technique, but successful full scale implementation is hindered by the empirical, trial-and-error nature of scale-up. We present an integrated approach leveraging at-line process analytical technology (PAT) and mass balance based modeling to de-risk MF scale-up. Chromatography-based PAT was employed to improve the consistency of an MF step that had been a bottleneck in the process used to manufacture a therapeutic protein. A 10-min reverse phase ultra high performance liquid chromatography (RP-UPLC) assay was developed to provide at-line monitoring of protein concentration. The method was successfully validated and method performance was comparable to previously validated methods. The PAT tool revealed areas of divergence from a mass balance-based model, highlighting specific opportunities for process improvement. Adjustment of appropriate process controls led to improved operability and significantly increased yield, providing a successful example of PAT deployment in the downstream purification of a therapeutic protein. The general approach presented here should be broadly applicable to reduce risk during scale-up of filtration processes and should be suitable for feed-forward and feed-back process control. © 2015 American Institute of Chemical Engineers.

  9. Parallel Reservoir Simulations with Sparse Grid Techniques and Applications to Wormhole Propagation

    KAUST Repository

    Wu, Yuanqing

    2015-01-01

    the traditional simulation technique relying on the Darcy framework, we propose a new framework called Darcy-Brinkman-Forchheimer framework to simulate wormhole propagation. Furthermore, to process the large quantity of cells in the simulation grid and shorten

  10. Application of propagation predictions to Earth/space telecommunications system design

    Science.gov (United States)

    1981-01-01

    The corresponding between a given propagation phenomenon and system performance is considered. Propagation data are related to system performance parameters, allowing the systems engineer to perform the analyses determining how well requirements are met by a given system design, and enabling the systems engineer to modify that design if necessary. The various ways of specifying performance criteria for different kinds of systems are discussed, and a general procedure for system design is presented and demonstrated.

  11. Marine Atmospheric Surface Layer and Its Application to Electromagnetic Wave Propagation

    Science.gov (United States)

    Wang, Q.

    2015-12-01

    An important application of the atmospheric surface layer research is to characterize the near surface vertical gradients in temperature and humidity in order to predict radar and radio communication conditions in the environment. In this presentation, we will give an overview of a new research initiative funded under the Office of Naval Research (ONR) Multi-University Research Initiative (MURI): the Coupled Air-Sea Processes and EM Ducting Research (CASPER). The objective is to fully characterize the marine atmospheric boundary layer (MABL) as an electromagnetic (EM) propagation environment with the emphasis of spatial and temporal heterogeneities and surface wave/swell effects, both of which contravene the underlying assumptions of Monin-Obukhov Similarity Theory (MOST) used in coupled environmental forecast models. Furthermore, coastal variability in the inversion atop the MABL presents a challenge to forecast models and also causes practical issues in EM prediction models. These issues are the target of investigation of CASPER. CASPER measurement component includes two major field campaigns: CASPER-East (2015 Duck, NC) and CASPER-West (2018 southern California). This presentation will show the extensive measurements to be made during the CASPER -East field campaign with the focus on the marine atmospheric surface layer measurements with two research vessels, two research aircraft, surface flux buoy, wave gliders, ocean gliders, tethered balloons, and rawinsondes. Unlike previous research on the marine surface layer with the focus on surface fluxes and surface flux parameterization, CASPER field campaigns also emphasize of the surface layer profiles and the validation of the surface layer flux-profile relationship originally derived over land surfaces. Results from CASPER pilot experiment and preliminary results from CASPER-East field campaign will be discussed.

  12. Nuclear data uncertainties propagation methods in Boltzmann/Bateman coupled problems: Application to reactivity in MTR

    International Nuclear Information System (INIS)

    Frosio, Thomas; Bonaccorsi, Thomas; Blaise, Patrick

    2016-01-01

    Highlights: • Hybrid methods are developed for uncertainty propagation. • These methods take into account the flux perturbation in the coupled problem. • We show that OAT and MC methods give coherent results, except for Pearson correlations. • Local sensitivity analysis is performed. - Abstract: A novel method has been developed to calculate sensitivity coefficients in coupled Boltzmann/Bateman problem for nuclear data (ND) uncertainties propagation on the reactivity. Different uncertainty propagation methodologies, such as One-At-a-Time (OAT) and hybrid Monte-Carlo/deterministic methods have been tested and are discussed on an actual example of ND uncertainty problem on a Material Testing Reactor (MTR) benchmark. Those methods, unlike total Monte Carlo (MC) sampling for uncertainty propagation and quantification (UQ), allow obtaining sensitivity coefficients, as well as Bravais–Pearson correlations values between Boltzmann and Bateman, during the depletion calculation for global neutronics parameters such as the effective multiplication coefficient. The methodologies are compared to a pure MC sampling method, usually considered as the “reference” method. It is shown that methodologies can seriously underestimate propagated variances, when Bravais–Pearson correlations on ND are not taken into account in the UQ process.

  13. Application of the Marsupial Paradigm to Tropical Cyclone Formation from Northwestward-Propagating Disturbances

    Science.gov (United States)

    Wang, Zhuo; Dunkerton, Timothy J.; Montgomery, Michael T.

    2012-01-01

    A wave-tracking algorithm is developed for northwestward-propagating waves that, on occasion, play a role in tropical cyclogenesis over the western oceans. To obtain the Lagrangian flow structure, the frame of reference is translated obliquely at the same propagation speed with the precursor disturbance. Trajectory analysis suggests that streamlines in the obliquely translated frame of reference can be used to approximate flow trajectories. The algorithm was applied to Super Typhoon Nakri (2008), Tropical Cyclone Erika (2009), and a few other examples. Diagnoses of meteorological analyses and satellite-derived moisture and precipitation fields show that the marsupial framework for tropical cyclogenesis in tropical easterly waves is relevant also for northwestward-propagating disturbances as are commonly observed in the tropical western Atlantic, the Gulf of Mexico, and the western North Pacific. Finally, it is suggested that analysis of the global model data and satellite observations in the marsupial framework can provide useful guidance on early tropical cyclone advisories.

  14. Complex-valued derivative propagation method with approximate Bohmian trajectories: Application to electronic nonadiabatic dynamics

    Science.gov (United States)

    Wang, Yu; Chou, Chia-Chun

    2018-05-01

    The coupled complex quantum Hamilton-Jacobi equations for electronic nonadiabatic transitions are approximately solved by propagating individual quantum trajectories in real space. Equations of motion are derived through use of the derivative propagation method for the complex actions and their spatial derivatives for wave packets moving on each of the coupled electronic potential surfaces. These equations for two surfaces are converted into the moving frame with the same grid point velocities. Excellent wave functions can be obtained by making use of the superposition principle even when nodes develop in wave packet scattering.

  15. Using PAT to accelerate the transition to continuous API manufacturing

    DEFF Research Database (Denmark)

    de Gouveia, Maria Francisca Dias Folque; Rahbek, Jesper P.; Mortensen, Asmus R.

    2017-01-01

    the following: speeding up the design of the continuous process and a better understanding of the manufacturing requirements to ensure optimal yield and avoid unreacted raw materials and by-products in the continuous reactor effluent. Graphical Abstract Using PAT to accelerate the transition to continuous API......Significant improvements can be realized by converting conventional batch processes into continuous ones. The main drivers include reduction of cost and waste, increased safety, and simpler scale-up and tech transfer activities. Re-designing the process layout offers the opportunity to incorporate...... a set of process analytical technologies (PAT) embraced in the Quality-by-Design (QbD) framework. These tools are used for process state estimation, providing enhanced understanding of the underlying variability in the process impacting quality and yield. This work describes a road map for identifying...

  16. Inline UV/Vis spectroscopy as PAT tool for hot-melt extrusion.

    Science.gov (United States)

    Wesholowski, Jens; Prill, Sebastian; Berghaus, Andreas; Thommes, Markus

    2018-01-11

    Hot-melt extrusion on co-rotating twin screw extruders is a focused technology for the production of pharmaceuticals in the context of Quality by Design. Since it is a continuous process, the potential for minimizing product quality fluctuation is enhanced. A typical application of hot-melt extrusion is the production of solid dispersions, where an active pharmaceutical ingredient (API) is distributed within a polymer matrix carrier. For this dosage form, the product quality is related amongst others to the drug content. This can be monitored on- or inline as critical quality attribute by a process analytical technology (PAT) in order to meet the specific requirements of Quality by Design. In this study, an inline UV/Vis spectrometer from ColVisTec was implemented in an early development twin screw extruder and the performance tested in accordance to the ICH Q2 guideline. Therefore, two API (carbamazepine and theophylline) and one polymer matrix (copovidone) were considered with the main focus on the quantification of the drug load. The obtained results revealed the suitability of the implemented PAT tool to quantify the drug load in a typical range for pharmaceutical applications. The effort for data evaluation was minimal due to univariate data analysis, and in combination with a measurement frequency of 1 Hz, the system is sufficient for real-time data acquisition.

  17. Dėl baltų *pat(is, *pat(nī pirminės reikšmės ir gramatinio statuso

    Directory of Open Access Journals (Sweden)

    Albertas Rosinas

    2011-11-01

    Full Text Available ON THE ORIGINAL MEANING AND THE GRAMMATICAL STATUS OF BALTIC *pat(is, *pat(nīSummaryOn the basis of the data from the Baltic and other Indo-European languages, the article rejects the common current view that Baltic *pat-root nouns, cf. Latv. pats ‘master, mister, husband’, pati ‘mistress, wife’, evolved from *pat-root pronouns with the meaning of ‘self’. The data from the Baltic languages lead to the conclusion that from Proto-Indo-European the Proto-Balts inherited the root noun of the consonantal declension *pat (pat (cf. I.-E. acc. sing. *potn̥> Baltic *patin and i-stem acc. sing. *avin passed to the i-stem declension, i. e. it was modified to *patis and began to be declined as an i-stem noun, although also retaining some C-stem forms; under the influence of the *patis model, *patnī gradually lost the suffix *-n- and became *patī (>Lith. patì, Latv. pati. The assumption that the Baltic nouns *patis, *patnī did not evolve from pronouns could be supported by the following: (a i-stem resp. C-stem pronominal paradigms are not characteristic of the Baltic pronominal systems; (b moreover, the Prussian language (like the German, Slavonic and Indo-Iranian languages never possessed *pat-root pronouns.In the East Baltic languages, pronouns with the meaning of ‘self’ evolved from the nouns *pat(is, *pat(nī in the process of pronominalization, which originally occurred in the sphere of the addressee and the non-participant person. In the process of pronominalization, *pat(is eventually acquired endings typical of pronouns, cf. dat. sing, pačiam <— pačiamu(i, ines. sing, patime and a newer form pačiame, dat. pl. patiems ← patiemus.The identifying particle pat in the collocative pronouns toks pat, tokia pat

  18. Brutal crack propagation in dynamic fracture: industrial application to the length of the crack arrest

    International Nuclear Information System (INIS)

    Dumouchel, P.E.

    2008-03-01

    This research thesis aims at understanding and analysing some mechanisms involved in the dynamic failure under various loadings which are notably present in industrial environment, and more particularly in some parts of EDF's plants where networks of micro-cracks may steadily grow: heterogeneous zones, defects under coating. The author presents a simplified model based on the de-bonding of a film to understand the mechanisms of a sudden failure under a quasi-static loading. He develops a similar model to explore the influence of a defect on crack propagation under a quasi-static loading, and then under a sudden loading. This model is then generalized to the case of several defects, and more particularly very small defects. Finally, the author gives a numerical interpretation of a sudden propagation under quasi-static loading

  19. Application of wire beam electrode technique to investigate initiation and propagation of rebar corrosion

    International Nuclear Information System (INIS)

    Shi, Wei; Dong, Ze Hua; Kong, De Jie; Guo, Xing Peng

    2013-01-01

    Multi-electrode technique named as wire beam electrode (WBE) was used to study pitting corrosion of rebar under concrete cover. When WBE embedded mortar sample was immersed in NaCl solution, uneven distributions of galvanic current and open circuit potential (OCP) on the WBE were observed due to the initiation of pitting corrosion. The following oxygen depletion in mortar facilitated the negative shift of the OCP and the smoothing of the current and potential distributions. Wetting–drying cycle experiments showed that corrosion products instead of oxygen in wet mortar specimen sustained the propagation of pitting corrosion due to Fe (III) taking part in cathodic depolarization during oxygen-deficient wet period, which was confirmed by micro-Raman spectroscopy. In addition, new pitting corrosion occurred mainly near the corrosion products, leading to preferentially horizontal propagation of rust layer on the WBE. A localized corrosion factor was further presented to quantify the localised corrosion based on galvanic current maps

  20. Application of wire beam electrode technique to investigate initiation and propagation of rebar corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Wei; Dong, Ze Hua, E-mail: zehua.dong@gmail.com; Kong, De Jie; Guo, Xing Peng

    2013-06-15

    Multi-electrode technique named as wire beam electrode (WBE) was used to study pitting corrosion of rebar under concrete cover. When WBE embedded mortar sample was immersed in NaCl solution, uneven distributions of galvanic current and open circuit potential (OCP) on the WBE were observed due to the initiation of pitting corrosion. The following oxygen depletion in mortar facilitated the negative shift of the OCP and the smoothing of the current and potential distributions. Wetting–drying cycle experiments showed that corrosion products instead of oxygen in wet mortar specimen sustained the propagation of pitting corrosion due to Fe (III) taking part in cathodic depolarization during oxygen-deficient wet period, which was confirmed by micro-Raman spectroscopy. In addition, new pitting corrosion occurred mainly near the corrosion products, leading to preferentially horizontal propagation of rust layer on the WBE. A localized corrosion factor was further presented to quantify the localised corrosion based on galvanic current maps.

  1. Development of fatigue crack propagation models for engineering applications at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Tomkins, B.

    1975-05-01

    The value of modelling the fatigue crack propagation process is discussed and current models are examined in the light of increasing knowledge of crack tip deformation. Elevated temperature fatigue is examined in detail as an area in which models could contribute significantly to engineering design. A model is developed which examines the role of time-dependent creep cavitation on the failure process in an interactive creep-fatigue situation. (auth)

  2. Process Analytical Technology (PAT): batch-to-batch reproducibility of fermentation processes by robust process operational design and control.

    Science.gov (United States)

    Gnoth, S; Jenzsch, M; Simutis, R; Lübbert, A

    2007-10-31

    The Process Analytical Technology (PAT) initiative of the FDA is a reaction on the increasing discrepancy between current possibilities in process supervision and control of pharmaceutical production processes and its current application in industrial manufacturing processes. With rigid approval practices based on standard operational procedures, adaptations of production reactors towards the state of the art were more or less inhibited for long years. Now PAT paves the way for continuous process and product improvements through improved process supervision based on knowledge-based data analysis, "Quality-by-Design"-concepts, and, finally, through feedback control. Examples of up-to-date implementations of this concept are presented. They are taken from one key group of processes in recombinant pharmaceutical protein manufacturing, the cultivations of genetically modified Escherichia coli bacteria.

  3. Development of Process Analytical Technology (PAT) methods for controlled release pellet coating.

    Science.gov (United States)

    Avalle, P; Pollitt, M J; Bradley, K; Cooper, B; Pearce, G; Djemai, A; Fitzpatrick, S

    2014-07-01

    This work focused on the control of the manufacturing process for a controlled release (CR) pellet product, within a Quality by Design (QbD) framework. The manufacturing process was Wurster coating: firstly layering active pharmaceutical ingredient (API) onto sugar pellet cores and secondly a controlled release (CR) coating. For each of these two steps, development of a Process Analytical Technology (PAT) method is discussed and also a novel application of automated microscopy as the reference method. Ultimately, PAT methods should link to product performance and the two key Critical Quality Attributes (CQAs) for this CR product are assay and release rate, linked to the API and CR coating steps respectively. In this work, the link between near infra-red (NIR) spectra and those attributes was explored by chemometrics over the course of the coating process in a pilot scale industrial environment. Correlations were built between the NIR spectra and coating weight (for API amount), CR coating thickness and dissolution performance. These correlations allow the coating process to be monitored at-line and so better control of the product performance in line with QbD requirements. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Wormholes propagation for fractured-vuggy formation: Laboratory tests, numerical simulation and field application

    Directory of Open Access Journals (Sweden)

    Fei Liu

    2017-12-01

    Full Text Available The propagation of wormhole is vital important for matrix acidizing and acid fracturing in carbonate reservoirs. While the formation of acid dissolved wormhole is derived from heterogeneous physical and chemical transportations and reactions. Alveolate dissolved pores, krast caves, and natural fissures are the major reservoir spaces for the Sinian dolomite formation in the Anyue gas field of the Sichuan Basin. There were four categories of formation, which are matrix dominated, inter-breccia dissolved pore dominated, dissolved pore and cave dominated, and fissure and cave dominated, based on the development intensity and connectedness of caves and fissures. The caves and fissures make the wormhole formation and propagation particularly complicated. Firstly, the 3-D topological structure of dissolved pores, vugs, fissures and throats inside cores is quantitatively scanned by CT imaging technology for its feature of vivid and damage-free. Secondly, 3-D patterns of wormhole are obtained with CT scanning after core flooding by acid. Additionally, the pore-throat network model is reconstructed with digital cores technology. Then, the size and ratio of pore and throat before and after core flooding by acid is analyzed and the absolute permeability of pore scale flow is numerically simulated to understand the fundamental influence of pores and vugs distribution and connectedness on wormhole propagation. Lastly, the wormhole pattern gained by CT scanning and simulating with two-scale model is compared. Meanwhile, the corrected two-scale model is utilized to simulate the wormhole propagation for matrix acidizing and acid fracturing of Sinian fractured-vuggy dolomite in Anyue gas field, Sichuan Basin. The optimized injection rate and volume were in agreement with the characteristic matrix acidizing operating curve, which indicates that the two-scale model was suitable for matrix acidizing optimization design of such formations. In addition, the simulated

  5. PAT: From Western solid dosage forms to Chinese materia medica preparations using NIR-CI.

    Science.gov (United States)

    Zhou, Luwei; Xu, Manfei; Wu, Zhisheng; Shi, Xinyuan; Qiao, Yanjiang

    2016-01-01

    Near-infrared chemical imaging (NIR-CI) is an emerging technology that combines traditional near-infrared spectroscopy with chemical imaging. Therefore, NIR-CI can extract spectral information from pharmaceutical products and simultaneously visualize the spatial distribution of chemical components. The rapid and non-destructive features of NIR-CI make it an attractive process analytical technology (PAT) for identifying and monitoring critical control parameters during the pharmaceutical manufacturing process. This review mainly focuses on the pharmaceutical applications of NIR-CI in each unit operation during the manufacturing processes, from the Western solid dosage forms to the Chinese materia medica preparations. Finally, future applications of chemical imaging in the pharmaceutical industry are discussed. Copyright © 2015 John Wiley & Sons, Ltd.

  6. PAT challenges routine techniques on defect spectroscopy in material science

    International Nuclear Information System (INIS)

    Badawi, E.A.

    2005-01-01

    Atomic or Point Defects are the most simple defects in solids. Due to the small size their direct observation by the routine techniques is not possible. A single type of defects (thermal defect) was observed in the quenching process. Using the Arrhenius method and threshold method we recommended the accurate both method of treatments. The calculated values for formation enthalpies and self-diffusion using positron lifetime and Doppler broadening in a good agreement in (A356.0) and (A413.1). Specifically it is show how PAT detect defect concentrations, (formation- migration) enthalpies and grain size for the material under investigation. Most of the these data are reported

  7. Plutonium air transportable package Model PAT-1. Safety analysis report

    International Nuclear Information System (INIS)

    1978-02-01

    The document is a Safety Analysis Report for the Plutonium Air Transportable Package, Model PAT-1, which was developed by Sandia Laboratories under contract to the Nuclear Regulatory Commission (NRC). The document describes the engineering tests and evaluations that the NRC staff used as a basis to determine that the package design meets the requirements specified in the NRC ''Qualification Criteria to Certify a Package for Air Transport of Plutonium'' (NUREG-0360). By virtue of its ability to meet the NRC Qualification Criteria, the package design is capable of safely withstanding severe aircraft accidents. The document also includes engineering drawings and specifications for the package. 92 figs, 29 tables

  8. Unpacking Pat Parker: Intersections and Revolutions in "Movement in Black".

    Science.gov (United States)

    Washburn, Amy

    2015-01-01

    This article explores Pat Parker's poem "Movement in Black." It examines the ways in which she emblematizes intersectionality and simultaneity as forms of revolution in struggles of self and society. It begins with a theoretical and historical apparatus to contextualize Parker as an artist and activist. Then it offers a literary analysis of the poem, focusing on themes of time and space, marginalization and movement, difference and power, visibility and invisibility, and history and memory. It argues that Parker uses autobiographical writing to fuse personal and political sites of resistance.

  9. Application of affinity propagation algorithm based on manifold distance for transformer PD pattern recognition

    Science.gov (United States)

    Wei, B. G.; Huo, K. X.; Yao, Z. F.; Lou, J.; Li, X. Y.

    2018-03-01

    It is one of the difficult problems encountered in the research of condition maintenance technology of transformers to recognize partial discharge (PD) pattern. According to the main physical characteristics of PD, three models of oil-paper insulation defects were set up in laboratory to study the PD of transformers, and phase resolved partial discharge (PRPD) was constructed. By using least square method, the grey-scale images of PRPD were constructed and features of each grey-scale image were 28 box dimensions and 28 information dimensions. Affinity propagation algorithm based on manifold distance (AP-MD) for transformers PD pattern recognition was established, and the data of box dimension and information dimension were clustered based on AP-MD. Study shows that clustering result of AP-MD is better than the results of affinity propagation (AP), k-means and fuzzy c-means algorithm (FCM). By choosing different k values of k-nearest neighbor, we find clustering accuracy of AP-MD falls when k value is larger or smaller, and the optimal k value depends on sample size.

  10. Beam propagation

    International Nuclear Information System (INIS)

    Hermansson, B.R.

    1989-01-01

    The main part of this thesis consists of 15 published papers, in which the numerical Beam Propagating Method (BPM) is investigated, verified and used in a number of applications. In the introduction a derivation of the nonlinear Schroedinger equation is presented to connect the beginning of the soliton papers with Maxwell's equations including a nonlinear polarization. This thesis focuses on the wide use of the BPM for numerical simulations of propagating light and particle beams through different types of structures such as waveguides, fibers, tapers, Y-junctions, laser arrays and crystalline solids. We verify the BPM in the above listed problems against other numerical methods for example the Finite-element Method, perturbation methods and Runge-Kutta integration. Further, the BPM is shown to be a simple and effective way to numerically set up the Green's function in matrix form for periodic structures. The Green's function matrix can then be diagonalized with matrix methods yielding the eigensolutions of the structure. The BPM inherent transverse periodicity can be untied, if desired, by for example including an absorptive refractive index at the computational window edges. The interaction of two first-order soliton pulses is strongly dependent on the phase relationship between the individual solitons. When optical phase shift keying is used in coherent one-carrier wavelength communication, the fiber attenuation will suppress or delay the nonlinear instability. (orig.)

  11. Thermal field theory in a layer: Applications of thermal field theory methods to the propagation of photons in a two-dimensional electron sheet

    International Nuclear Information System (INIS)

    Nieves, Jose F.

    2010-01-01

    We apply the thermal field theory methods to study the propagation of photons in a plasma layer, that is a plasma in which the electrons are confined to a two-dimensional plane sheet. We calculate the photon self-energy and determine the appropriate expression for the photon propagator in such a medium, from which the properties of the propagating modes are obtained. The formulas for the photon dispersion relations and polarization vectors are derived explicitly in some detail for some simple cases of the thermal distributions of the charged particle gas, and appropriate formulas that are applicable in more general situations are also given.

  12. Numerical simulations of wave propagation in long bars with application to Kolsky bar testing

    Energy Technology Data Exchange (ETDEWEB)

    Corona, Edmundo [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-11-01

    Material testing using the Kolsky bar, or split Hopkinson bar, technique has proven instrumental to conduct measurements of material behavior at strain rates in the order of 103 s-1. Test design and data reduction, however, remain empirical endeavors based on the experimentalist's experience. Issues such as wave propagation across discontinuities, the effect of the deformation of the bar surfaces in contact with the specimen, the effect of geometric features in tensile specimens (dog-bone shape), wave dispersion in the bars and other particulars are generally treated using simplified models. The work presented here was conducted in Q3 and Q4 of FY14. The objective was to demonstrate the feasibility of numerical simulations of Kolsky bar tests, which was done successfully.

  13. Application of perturbation theory methods to nuclear data uncertainty propagation using the collision probability method

    International Nuclear Information System (INIS)

    Sabouri, Pouya

    2013-01-01

    This thesis presents a comprehensive study of sensitivity/uncertainty analysis for reactor performance parameters (e.g. the k-effective) to the base nuclear data from which they are computed. The analysis starts at the fundamental step, the Evaluated Nuclear Data File and the uncertainties inherently associated with the data they contain, available in the form of variance/covariance matrices. We show that when a methodical and consistent computation of sensitivity is performed, conventional deterministic formalisms can be sufficient to propagate nuclear data uncertainties with the level of accuracy obtained by the most advanced tools, such as state-of-the-art Monte Carlo codes. By applying our developed methodology to three exercises proposed by the OECD (Uncertainty Analysis for Criticality Safety Assessment Benchmarks), we provide insights of the underlying physical phenomena associated with the used formalisms. (author)

  14. Analytical Uncertainty Propagation in Life Cycle Inventory and Impact Assessment: Application to an Automobile Front Panel

    DEFF Research Database (Denmark)

    Hong, Jinglan; Shaked, Shanna; Rosenbaum, Ralph K.

    2010-01-01

    to develop and apply to both inventory and impact assessment an explicit and transparent analytical approach to uncertainty. This approach applies Taylor series expansions to the uncertainty propagation of lognormally distributed parameters. Materials and methods We first apply the Taylor series expansion...... determine a range and a best estimate of a) the squared geometric standard deviation on the ratio of the two scenario scores, "A/B", and b) the degree of confidence in the prediction that the impact of scenario A is lower than B (i.e., the probability that A/B75%). For the aluminum panel, the electricity...... and aluminum primary production, as well as the light oil consumption, are the dominant contributors to the uncertainty. The developed approach for scenario comparisons, differentiating between common and independent parameters, leads to results similar to those of a Monte Carlo analysis; for all tested cases...

  15. Long Range Sound Propagation over Sea: Application to Wind Turbine Noise

    Energy Technology Data Exchange (ETDEWEB)

    Boue, Matieu

    2007-12-13

    The classical theory of spherical wave propagation is not valid at large distances from a sound source due to the influence of wind and temperature gradients that refract, i.e., bend the sound waves. This will in the downwind direction lead to a cylindrical type of wave spreading for large distances (> 1 km). Cylindrical spreading will give a smaller damping with distance as compared to spherical spreading (3 dB/distance doubling instead of 6 dB). But over areas with soft ground, i.e., grass land, the effect of ground reflections will increase the damping so that, if the effect of atmospheric damping is removed, a behavior close to a free field spherical spreading often is observed. This is the standard assumption used in most national recommendations for predicting outdoor sound propagation, e.g., noise from wind turbines. Over areas with hard surfaces, e.g., desserts or the sea, the effect of ground damping is small and therefore cylindrical propagation could be expected in the downwind direction. This observation backed by a limited number of measurements is the background for the Swedish recommendation, which suggests that cylindrical wave spreading should be assumed for distances larger than 200 m for sea based wind turbines. The purpose of this work was to develop measurement procedures for long range sound transmission and to apply this to investigate the occurrence of cylindrical wave spreading in the Baltic Sea. This work has been successfully finished and is described in this report. Another ambition was to develop models for long range sound transmission based on the parabolic equation. Here the work is not finished but must be continued in another project. Long term measurements were performed in the Kalmar strait, Sweden, located between the mainland and Oeland, during 2005 and 2006. Two different directive sound sources placed on a lighthouse in the middle of the strait produced low frequency tones at 80, 200 and 400 Hz. At the reception point on

  16. Application of the error propagation theory in estimates of static formation temperatures in geothermal and petroleum boreholes

    International Nuclear Information System (INIS)

    Verma, Surendra P.; Andaverde, Jorge; Santoyo, E.

    2006-01-01

    We used the error propagation theory to calculate uncertainties in static formation temperature estimates in geothermal and petroleum wells from three widely used methods (line-source or Horner method; spherical and radial heat flow method; and cylindrical heat source method). Although these methods commonly use an ordinary least-squares linear regression model considered in this study, we also evaluated two variants of a weighted least-squares linear regression model for the actual relationship between the bottom-hole temperature and the corresponding time functions. Equations based on the error propagation theory were derived for estimating uncertainties in the time function of each analytical method. These uncertainties in conjunction with those on bottom-hole temperatures were used to estimate individual weighting factors required for applying the two variants of the weighted least-squares regression model. Standard deviations and 95% confidence limits of intercept were calculated for both types of linear regressions. Applications showed that static formation temperatures computed with the spherical and radial heat flow method were generally greater (at the 95% confidence level) than those from the other two methods under study. When typical measurement errors of 0.25 h in time and 5 deg. C in bottom-hole temperature were assumed for the weighted least-squares model, the uncertainties in the estimated static formation temperatures were greater than those for the ordinary least-squares model. However, if these errors were smaller (about 1% in time and 0.5% in temperature measurements), the weighted least-squares linear regression model would generally provide smaller uncertainties for the estimated temperatures than the ordinary least-squares linear regression model. Therefore, the weighted model would be statistically correct and more appropriate for such applications. We also suggest that at least 30 precise and accurate BHT and time measurements along with

  17. Test of a sample container for shipment of small size plutonium samples with PAT-2

    International Nuclear Information System (INIS)

    Kuhn, E.; Aigner, H.; Deron, S.

    1981-11-01

    A light-weight container for the air transport of plutonium, to be designated PAT-2, has been developed in the USA and is presently undergoing licensing. The very limited effective space for bearing plutonium required the design of small size sample canisters to meet the needs of international safeguards for the shipment of plutonium samples. The applicability of a small canister for the sampling of small size powder and solution samples has been tested in an intralaboratory experiment. The results of the experiment, based on the concept of pre-weighed samples, show that the tested canister can successfully be used for the sampling of small size PuO 2 -powder samples of homogeneous source material, as well as for dried aliquands of plutonium nitrate solutions. (author)

  18. Light propagation and emission in scattering media. Application to imaging of complex media

    International Nuclear Information System (INIS)

    Pierrat, Romain

    2007-01-01

    In this manuscript, we raise different aspects of the propagation and emission of electromagnetic waves in a scattering medium. In the first part, we show that the Radiative Transfer Equation (rte) is a very good tool to study light propagation in a complex medium. Thanks to this formalism, we study the evolution of the spatial coherence of the beam inside the medium, which is seen as a signature of the different transport regimes of photons (single scattering, multiple scattering, diffusive regime). Next, we derive rigorously the diffusion approximation by using a modal approach of the rte. In particular, we obtain that the diffusion coefficient is independent of the level of absorption in the dynamic regime while it depends on absorption in the case of the steady-state regime. Finally, we study the temporal fluctuations of the scattered intensity and show that the use of the rte allows to go beyond the diffusive regime described by the diffusing-waves spectroscopy theory (dws). Comparisons between numerical computations and experiments are realized in reflexion to underline the fundamental role of the anisotropy of the scattering, which is not described by the standard theory. The second part is dedicated to the study of light emission in complex media. First, we study the amplification of scattered light in a gain system called random laser and show that it exists a laser threshold in the incoherent feedback regime. This threshold is quantified by using a modal approach of the rte. Thanks to this formalism, we highlight the limitations of the diffusion approximation in such a system. Next, we study the modification of the fluorescent decay rate of a single molecule embedded in a complex medium. We derive a model allowing the replacement of the scattering medium by an homogeneous equivalent medium taking into account the multiple scattering and the interactions between scatterers. This model is validated by comparison with the value of the decay rate of the

  19. Atmospheric pressure argon surface discharges propagated in long tubes: physical characterization and application to bio-decontamination

    International Nuclear Information System (INIS)

    Kovalova, Zuzana; Leroy, Magali; Jacobs, Carolyn; Kirkpatrick, Michael J; Odic, Emmanuel; Machala, Zdenko; Lopes, Filipa; Laux, Christophe O; DuBow, Michael S

    2015-01-01

    Pulsed corona discharges propagated in argon (or in argon with added water vapor) at atmospheric pressure on the interior surface of a 49 cm long quartz tube were investigated for the application of surface bio-decontamination. H 2 O molecule dissociation in the argon plasma generated reactive species (i.e. OH in ground and excited states) and UV emission, which both directly affected bacterial cells. In order to facilitate the evaluation of the contribution of UV radiation, a DNA damage repair defective bacterial strain, Escherichia coli DH-1, was used. Discharge characteristics, including propagation velocity and plasma temperature, were measured. Up to ∼5.5 and ∼5 log 10 reductions were observed for E. coli DH-1 bacteria (from 10 6 initial load) exposed 2 cm and 44 cm away from the charged electrode, respectively, for a 20 min plasma treatment. The factors contributing to the observed bactericidal effect include desiccation, reactive oxygen species (OH) plus H 2 O 2 accumulation in the liquid phase, and UV-B (and possibly VUV) emission in dry argon. The steady state temperature measured on the quartz tube wall did not exceeded 29 °C; the contribution of heating, along with that of H 2 O 2 accumulation, was estimated to be low. The effect of UV-B emission alone or in combination with the other stress factors of the plasma process was examined for different operating conditions. (paper)

  20. Application of distributed point source method (DPSM) to wave propagation in anisotropic media

    Science.gov (United States)

    Fooladi, Samaneh; Kundu, Tribikram

    2017-04-01

    Distributed Point Source Method (DPSM) was developed by Placko and Kundu1, as a technique for modeling electromagnetic and elastic wave propagation problems. DPSM has been used for modeling ultrasonic, electrostatic and electromagnetic fields scattered by defects and anomalies in a structure. The modeling of such scattered field helps to extract valuable information about the location and type of defects. Therefore, DPSM can be used as an effective tool for Non-Destructive Testing (NDT). Anisotropy adds to the complexity of the problem, both mathematically and computationally. Computation of the Green's function which is used as the fundamental solution in DPSM is considerably more challenging for anisotropic media, and it cannot be reduced to a closed-form solution as is done for isotropic materials. The purpose of this study is to investigate and implement DPSM for an anisotropic medium. While the mathematical formulation and the numerical algorithm will be considered for general anisotropic media, more emphasis will be placed on transversely isotropic materials in the numerical example presented in this paper. The unidirectional fiber-reinforced composites which are widely used in today's industry are good examples of transversely isotropic materials. Development of an effective and accurate NDT method based on these modeling results can be of paramount importance for in-service monitoring of damage in composite structures.

  1. Modeling elastic wave propagation in kidney stones with application to shock wave lithotripsy.

    Science.gov (United States)

    Cleveland, Robin O; Sapozhnikov, Oleg A

    2005-10-01

    A time-domain finite-difference solution to the equations of linear elasticity was used to model the propagation of lithotripsy waves in kidney stones. The model was used to determine the loading on the stone (principal stresses and strains and maximum shear stresses and strains) due to the impact of lithotripsy shock waves. The simulations show that the peak loading induced in kidney stones is generated by constructive interference from shear waves launched from the outer edge of the stone with other waves in the stone. Notably the shear wave induced loads were significantly larger than the loads generated by the classic Hopkinson or spall effect. For simulations where the diameter of the focal spot of the lithotripter was smaller than that of the stone the loading decreased by more than 50%. The constructive interference was also sensitive to shock rise time and it was found that the peak tensile stress reduced by 30% as rise time increased from 25 to 150 ns. These results demonstrate that shear waves likely play a critical role in stone comminution and that lithotripters with large focal widths and short rise times should be effective at generating high stresses inside kidney stones.

  2. Application of self-propagation high-temperature synthesis for immobilization of hard radioactive wastes in ceramet materials

    International Nuclear Information System (INIS)

    Ilyin, E.; Pashkeev, I.; Senin, A.; Gerasimova, N.

    2001-01-01

    The possibility of self-propagating high-temperature synthesis (SPHTS) application for an immobilization of solid high level wastes (HLW) in cermet materials is considered. The schemes of multilayer cermet blocks formation are offered. Such blocks consist of a ceramet core with immobilized HLW and a protective cover - ceramet without HLW. The influence of the base components form (pure Ti and Si, ferrotitanium and ferrosilicon), metallic components (Ni, Cu, Cr, Fe, ferrochromium) and nonmetallic components (SiO 2 , Al 2 O 3 , TiO 2 ) on burning rate and cover ceramet structure is investigated in compositions on a basis of Ti+B, Ti+Si, Ti+C systems. Model samples of multilayer cermet blocks are manufactured using of HLW simulators. (authors)

  3. Investigation on the ultrasonic propagation mechanism and its application on air-source heat pump defrosting

    International Nuclear Information System (INIS)

    Tan, Haihui; Xu, Guanghua; Tao, Tangfei; Zhang, Sicong; Luo, Ailing

    2016-01-01

    Highlights: • Optimal defrosting mode for finned-tube evaporator is S0 mode. • Stress excited by ultrasonic vibration is larger than ice adhesion stress 0.4 MPa. • Frequency matching can enhance the defrosting efficiency effectively. • Ultrasonic vibration can effectively suppressing the frost deposition. • Thermal comfort and heat transfer efficiency enhanced with ultrasonic vibration. - Abstract: Frosting deposited on the outdoor coil of air-source heat pump (ASHP) units deteriorates the operational performance and energy efficiency. Therefore, periodic defrosting is necessary. First, the dispersion curves for the propagation mechanism of an ultrasonic guided wave in the evaporator are determined through numerical calculation. In addition, the shear stress and vibration characteristics under ultrasonic excitation are analysed using finite element method (FEM). Finally, the vibration amplitude and defrosting performance of ultrasonic vibration is analysed. The numerical calculation results indicate that three guided wave modes exist in the evaporator, including both A0 and S0 modes of the Lamb wave and SH0 mode of the SH wave, with the optimal defrosting mode being S0 of the Lamb wave. The FEM results show that the vibrational shapes of S0 mode and longitudinal mode clearly exists in the fin and tube, the torsional and flexural modes also exist in the tube, and the FEM results are consistent with the numerical calculation results. The impedance analysis and laser vibrometer results indicate that the resonance frequency shifting, electro-acoustic converting efficiency and vibration energy decrease is due to increasing external load. The ultrasonic defrosting experimental results indicate that ultrasonic vibration can suppress frost deposit on the fin surface.

  4. UN_PAT: a software for calculating transient grounding potential

    Directory of Open Access Journals (Sweden)

    Johny Hernán Montaña

    2006-09-01

    Full Text Available This paper presents results from work done at the National University of Colombia and from a PhD thesis written there. This work was aimed at implementing software for analysing the transient behaviour of any configuration of grounding system buried in lineal, homogeneous and isotropic soil. The hybrid electromagnetic model (HEM was used because it presents high versatility and low computation time. The UN_PAT software was written in C++; it used free libraries with the aim of being free software so that it could be modified and improved in future work. The software results were validated with other software, with results from another analysis model and experimental results; some of these comparisons are given in this paper.

  5. Processing of baby food using pressure-assisted thermal sterilization (PATS) and comparison with thermal treatment

    Science.gov (United States)

    Wang, Yubin; Ismail, Marliya; Farid, Mohammed

    2017-10-01

    Currently baby food is sterilized using retort processing that gives an extended shelf life. However, this type of heat processing leads to reduction of organoleptic and nutrition value. Alternatively, the combination of pressure and heat could be used to achieve sterilization at reduced temperatures. This study investigates the potential of pressure-assisted thermal sterilization (PATS) technology for baby food sterilization. Here, baby food (apple puree), inoculated with Bacillus subtilis spores was treated using PATS at different operating temperatures, pressures and times and was compared with thermal only treatment. The results revealed that the decimal reduction time of B. subtilis in PATS treatment was lower than that of thermal only treatment. At a similar spore inactivation, the retention of ascorbic acid of PATS-treated sample was higher than that of thermally treated sample. The results indicated that PATS could be a potential technology for baby food processing while minimizing quality deterioration.

  6. The pat1 protein kinase controls transcription of the mating-type genes in fission yeast

    DEFF Research Database (Denmark)

    Nielsen, O; Egel, R; Nielsen, Olaf

    1990-01-01

    . This differentiation process is characterized by a transcriptional induction of the mating-type genes. Conjugation can also be induced in pat1-ts mutants by a shift to a semi-permissive temperature. The pat1 gene encodes a protein kinase, which also functions further downstream in the developmental pathway controlling...... of the mating-type genes in the zygote leads to complete loss of pat1 protein kinase activity causing entry into meiosis. Thus, pat1 can promote its own inactivation. We suggest a model according to which a stepwise inactivation of pat1 leads to sequential derepression of the processes of conjugation......The developmental programme of fission yeast brings about a transition from mitotic cell division to the dormant state of ascospores. In response to nitrogen starvation, two cells of opposite mating type conjugate to form a diploid zygote, which then undergoes meiosis and sporulation...

  7. MANGO PROPAGATION

    OpenAIRE

    ALBERTO CARLOS DE QUEIROZ PINTO; VICTOR GALÁN SAÚCO; SISIR KUMAR MITRA; FRANCISCO RICARDO FERREIRA

    2018-01-01

    ABSTRACT This Chapter has the objectives to search, through the review of the available literature, important informations on the evolution of mango propagation regarding theoretical and practical aspects from cellular base of sexual propagation, nursery structures and organizations, substrate compositions and uses, importance of rootstock and scion selections, also it will be described the preparation and transport of the grafts (stem and bud) as well as the main asexual propagation methods...

  8. Tsunami Generation and Propagation by 3D deformable Landslides and Application to Scenarios

    Science.gov (United States)

    McFall, Brian C.; Fritz, Hermann M.

    2014-05-01

    Tsunamis generated by landslides and volcano flank collapse account for some of the most catastrophic natural disasters recorded and can be particularly devastative in the near field region due to locally high wave amplitudes and runup. The events of 1958 Lituya Bay, 1963 Vajont reservoir, 1980 Spirit Lake, 2002 Stromboli and 2010 Haiti demonstrate the danger of tsunamis generated by landslides or volcano flank collapses. Unfortunately critical field data from these events is lacking. Source and runup scenarios based on real world events are physically modeled using generalized Froude similarity in the three dimensional NEES tsunami wave basin at Oregon State University. A novel pneumatic landslide tsunami generator (LTG) was deployed to simulate landslides with varying geometry and kinematics. The bathymetric and topographic scenarios tested with the LTG are the basin-wide propagation and runup, fjord, curved headland fjord and a conical island setting representing a landslide off an island or a volcano flank collapse. The LTG consists of a sliding box filled with 1,350 kg of landslide material which is accelerated by means of four pneumatic pistons down a 2H:1V slope. The landslide is launched from the sliding box and continues to accelerate by gravitational forces up to velocities of 5 m/s. The landslide Froude number at impact with the water is in the range 1

  9. The process of earthflow propagation: insights from an application of the SPH technique to a case history

    Science.gov (United States)

    Lollino, Piernicola; Giordan, Daniele; Allasia, Paolo; Pastor, Manuel

    2016-04-01

    An intense reactivation of a large earthflow (about 6 million m3 of soil debris) took place in Montaguto (Southern Apennines, Italy) between 2005 and 2006 as a consequence of the retrogression of a sliding process in the source area at the top of the slope. The earthflow run-out was approximately 2-2.5 km long, with the landslide mass thickness approximately ranging between 5 m and 30 m. Relevant damages were produced at the toe of the slope, since important infrastructures hereby located were covered by large volumes of landslide detritum. In the transition area, that is just downslope the source area, the landslide soil mass was channelized and transformed into a viscous soil flowing down through a natural depression channel, with an average displacement rate estimated to range between 3 and 7 m/day. In this work an application of the Smoothed Particle Hydrodynamics method has been carried out in order to simulate both the main features of the earthflow propagation, that is the direction and the thickness of the flowing mass, as well as to investigate some factors of the soil mechanical behavior that might have controlled the earthflow mobility. In particular, two different assumptions concerning the soil rheology, i.e. Bingham visco-plasticity and frictional-consolidating soil, the first complying more with the assumption of a flow-like behavior and the latter with a soil-like behavior of the landslide mass, have been made for comparison purposes. Based on the experiences gained from previous authors concerning the in-situ features of similar earthflow soil masses, these landslides are thought to behave more as a viscous fluid during the very first stages of propagation due to phase transition processes and, later on, to recover a soil-like behavior, therefore characterized by sliding mechanism, due to soil consolidation processes. Field evidences of consolidation processes have indeed been observed in situ in recent years based on pore water pressure monitoring

  10. 绚丽秀美,气势迫人 Pat Metheny/Brad Mehldau 《Metheny Mehldau》

    Institute of Scientific and Technical Information of China (English)

    马其发

    2007-01-01

    <正>爵士吉他高手Pat Metheny的作品通常"兵分两路",一是以Pat Metheny Group集体创作出碟,玩Crossover Jazz或Fusjon为主;另一是以Pat Metheny名义与一些乐坛名宿合作,玩Contemporary Jazz、Folk Jazz和

  11. Variational formulation of the method of lines and its application to the wave propagation problems

    CSIR Research Space (South Africa)

    Shatalov, M

    2011-07-01

    Full Text Available accuracy is ( )3 ,O h u t x???? ??? ? (for (1) the error has order ( )2 ,O h u t x??? ??? ? ). For the second order derivative: 18th International Congress on Sound and Vibration, Rio de Janeiro, Brazil, 10-14 July 2011 3... ? ??? ?? ??? ? and first derivative calculation with accuracy ( ) 2 2 2 ,u t xO h x ? ?? ?? ??? ? , gives us the same result as application of the finite difference scheme of accuracy ( ) 4 4 4 ,u t xO h x ? ?? ?? ??? ? to calculation of the second...

  12. Application of Interfacial Propagation and Kinking Crack Concept to ECC/Concrete Overlay Repair System

    Directory of Open Access Journals (Sweden)

    Yaw ChiaHwan

    2014-01-01

    Full Text Available Research on the application of ultraductile engineered cementitious composite (ECC as overlay in the repair of deteriorated concrete structures is performed in this paper. Also, interfacial crack kinking and trapping mechanism experimentally observed in ECC/concrete overlay repair system are described by comparison of toughness and energy release rate. The mechanism involves cycles of extension, kinking, and arrest of interfacial crack into the overlay. Experimental testing of overlay repair system reveals significant improvements in load carrying capacity and ductility over conventional concrete overlay. The commonly observed overlay system failure mode of delamination or spalling is eliminated when ECC is applied. These failure modes are suppressed when ECC is used as an ideal and durable candidate overlay repair material.

  13. Assessment of Recent Process Analytical Technology (PAT) Trends: A Multiauthor Review

    DEFF Research Database (Denmark)

    Simon, Levente L.; Pataki, Hajnalka; Marosi, György

    2015-01-01

    in industrial laboratories and in manufacture e.g. at GSK, AstraZeneca and Roche. Furthermore, the paper discusses the PAT paradigm from the regulatory science perspective. Given the multidisciplinary nature of PAT, such an endeavour would be almost impossible for a single author, so the concept...... of a multiauthor review was born. Each section of the multiauthor review has been written by a single expert or group of experts with the aim to report on its own research results. This paper also serves as a comprehensive source of information on PAT topics for the novice reader....

  14. MANGO PROPAGATION

    Directory of Open Access Journals (Sweden)

    ALBERTO CARLOS DE QUEIROZ PINTO

    2018-03-01

    Full Text Available ABSTRACT This Chapter has the objectives to search, through the review of the available literature, important informations on the evolution of mango propagation regarding theoretical and practical aspects from cellular base of sexual propagation, nursery structures and organizations, substrate compositions and uses, importance of rootstock and scion selections, also it will be described the preparation and transport of the grafts (stem and bud as well as the main asexual propagation methods their uses and practices. Finally, pattern and quality of graft mangos and their commercialization aspects will be discussed in this Chapter.

  15. The mechanics and physics of fracturing: application to thermal aspects of crack propagation and to fracking.

    Science.gov (United States)

    Cherepanov, Genady P

    2015-03-28

    By way of introduction, the general invariant integral (GI) based on the energy conservation law is presented, with mention of cosmic, gravitational, mass, elastic, thermal and electromagnetic energy of matter application to demonstrate the approach, including Coulomb's Law generalized for moving electric charges, Newton's Law generalized for coupled gravitational/cosmic field, the new Archimedes' Law accounting for gravitational and surface energy, and others. Then using this approach the temperature track behind a moving crack is found, and the coupling of elastic and thermal energies is set up in fracturing. For porous materials saturated with a fluid or gas, the notion of binary continuum is used to introduce the corresponding GIs. As applied to the horizontal drilling and fracturing of boreholes, the field of pressure and flow rate as well as the fluid output from both a horizontal borehole and a fracture are derived in the fluid extraction regime. The theory of fracking in shale gas reservoirs is suggested for three basic regimes of the drill mud permeation, with calculating the shape and volume of the local region of the multiply fractured rock in terms of the pressures of rock, drill mud and shale gas. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  16. A database of fragmentation cross section measurements applicable to cosmic ray propagation calculations

    International Nuclear Information System (INIS)

    Crawford, H.J.; Engelage, J.; Jones, F.C.

    1989-08-01

    A database of single particle inclusive fragment production cross section measurements has been established and is accessible over common computer networks. These measurements have been obtained from both published literature and direct communication with experimenters and include cross sections for nuclear beams on H, He, and heavier targets, and for H and He beams on nuclear targets, for energies >30 MeV/nucleon. These cross sections are directly applicable to calculations involving cosmic ray nuclear interactions with matter. The data base includes projectile, target, and fragment specifications, beam energy, cross section with uncertainty, literature reference, and comment code. It is continuously updated to assure accuracy and completeness. Also available are widely used semi-empirical formulations for calculating production cross sections and excitation functions. In this paper we discuss the database in detail and describe how it can be accessed. We compare the measurements with semi-empirical calculations and point out areas where improved calculations and further cross section measurements are required. 5 refs., 2 figs

  17. A viscoelastic model for the prediction of transcranial ultrasound propagation: application for the estimation of shear acoustic properties in the human skull

    Science.gov (United States)

    Pichardo, Samuel; Moreno-Hernández, Carlos; Drainville, Robert Andrew; Sin, Vivian; Curiel, Laura; Hynynen, Kullervo

    2017-09-01

    A better understanding of ultrasound transmission through the human skull is fundamental to develop optimal imaging and therapeutic applications. In this study, we present global attenuation values and functions that correlate apparent density calculated from computed tomography scans to shear speed of sound. For this purpose, we used a model for sound propagation based on the viscoelastic wave equation (VWE) assuming isotropic conditions. The model was validated using a series of measurements with plates of different plastic materials and angles of incidence of 0°, 15° and 50°. The optimal functions for transcranial ultrasound propagation were established using the VWE, scan measurements of transcranial propagation with an angle of incidence of 40° and a genetic optimization algorithm. Ten (10) locations over three (3) skulls were used for ultrasound frequencies of 270 kHz and 836 kHz. Results with plastic materials demonstrated that the viscoelastic modeling predicted both longitudinal and shear propagation with an average (±s.d.) error of 9(±7)% of the wavelength in the predicted delay and an error of 6.7(±5)% in the estimation of transmitted power. Using the new optimal functions of speed of sound and global attenuation for the human skull, the proposed model predicted the transcranial ultrasound transmission for a frequency of 270 kHz with an expected error in the predicted delay of 5(±2.7)% of the wavelength. The sound propagation model predicted accurately the sound propagation regardless of either shear or longitudinal sound transmission dominated. For 836 kHz, the model predicted accurately in average with an error in the predicted delay of 17(±16)% of the wavelength. Results indicated the importance of the specificity of the information at a voxel level to better understand ultrasound transmission through the skull. These results and new model will be very valuable tools for the future development of transcranial applications of

  18. [The Patient Rights Act (PatRG)--part 1: legislative procedure, treatment contract, contracting parties and their obligations to cooperate and inform].

    Science.gov (United States)

    Parzeller, Markus; Zedler, Barbara

    2013-01-01

    The article deals with the new regulations in the German Civil Code (BGB) which came into effect in Germany on 26 Feb 2013 as the Patient Rights Act (PatRG). In Part I, the legislative procedure, the treatment contract and the contracting parties (Section 630a Civil Code), the applicable regulations (Section 630b Civil Code) and the obligations to cooperate and inform (Section 630c Civil Code) are discussed and critically analysed.

  19. New PAT tools for assessing content uniformity, sampling error, and degree of crystallinity in pharmaceutical tablets

    DEFF Research Database (Denmark)

    Warnecke, Solveig

    of the pharmaceutical drug, both during development and throughout the production. The usage of PAT tools is encouraged by the regulatory authorities, and therefore the interest in new and improved PAT tools is increasing. The main purpose of introducing Quality by Design (QbD) and PAT in pharmaceutical production...... practice in traditional pharmaceutical industry. In this thesis, three spectroscopic PAT tools are investigated, near-infrared-, terahertz-, and fluorescence-spectroscopy. These techniques have been evaluated with chemometrics and theory of sampling. The first study focused on the critical but rather...... overlooked sampling uncertainty that exist in all analytical measurements. The sampling error was studied using an example involving near infrared transmission (NIT) spectroscopy to study content of uniformity of five batches of escitalopram tablets, produced at different active pharmaceutical ingredients...

  20. Propagation of error from parameter constraints in quantitative MRI: Example application of multiple spin echo T2 mapping.

    Science.gov (United States)

    Lankford, Christopher L; Does, Mark D

    2018-02-01

    Quantitative MRI may require correcting for nuisance parameters which can or must be constrained to independently measured or assumed values. The noise and/or bias in these constraints propagate to fitted parameters. For example, the case of refocusing pulse flip angle constraint in multiple spin echo T 2 mapping is explored. An analytical expression for the mean-squared error of a parameter of interest was derived as a function of the accuracy and precision of an independent estimate of a nuisance parameter. The expression was validated by simulations and then used to evaluate the effects of flip angle (θ) constraint on the accuracy and precision of T⁁2 for a variety of multi-echo T 2 mapping protocols. Constraining θ improved T⁁2 precision when the θ-map signal-to-noise ratio was greater than approximately one-half that of the first spin echo image. For many practical scenarios, constrained fitting was calculated to reduce not just the variance but the full mean-squared error of T⁁2, for bias in θ⁁≲6%. The analytical expression derived in this work can be applied to inform experimental design in quantitative MRI. The example application to T 2 mapping provided specific cases, depending on θ⁁ accuracy and precision, in which θ⁁ measurement and constraint would be beneficial to T⁁2 variance or mean-squared error. Magn Reson Med 79:673-682, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  1. From Wireless Sensor Networks to Wireless Body Area Networks: Formal Modeling and Verification on Security Using PAT

    Directory of Open Access Journals (Sweden)

    Tieming Chen

    2016-01-01

    Full Text Available Model checking has successfully been applied on verification of security protocols, but the modeling process is always tedious and proficient knowledge of formal method is also needed although the final verification could be automatic depending on specific tools. At the same time, due to the appearance of novel kind of networks, such as wireless sensor networks (WSN and wireless body area networks (WBAN, formal modeling and verification for these domain-specific systems are quite challenging. In this paper, a specific and novel formal modeling and verification method is proposed and implemented using an expandable tool called PAT to do WSN-specific security verification. At first, an abstract modeling data structure for CSP#, which is built in PAT, is developed to support the node mobility related specification for modeling location-based node activity. Then, the traditional Dolev-Yao model is redefined to facilitate modeling of location-specific attack behaviors on security mechanism. A throughout formal verification application on a location-based security protocol in WSN is described in detail to show the usability and effectiveness of the proposed methodology. Furthermore, also a novel location-based authentication security protocol in WBAN can be successfully modeled and verified directly using our method, which is, to the best of our knowledge, the first effort on employing model checking for automatic analysis of authentication protocol for WBAN.

  2. Enfermedad diarreica aguda por Escherichia coli patógenas en Colombia

    Science.gov (United States)

    Gómez-Duarte, Oscar G.

    2014-01-01

    Resumen Las cepas de E. coli patógenas intestinales son causas importantes de la enfermedad diarreica aguda (EDA) en niños menores de 5 años en América Latina, África y Asia y están asociadas a alta mortalidad en niños en las comunidades más pobres de África y el Sudeste Asiático. Estudios sobre el papel de las E. coli patógenas intestinales en la EDA infantil en Colombia y otros países de América Latina son limitados debido a la carencia de ensayos para detección de estos patógenos en los laboratorios clínicos de centros de salud. Estudios recientes han reportado la detección de E. coli patógenas intestinales en Colombia, siendo la E. coli enterotoxigénica la cepa más frecuentemente asociada a diarrea en niños menores de 5 años. Otros patógenos detectados en estos pacientes incluyen las E. coli enteroagregativa, enteropatógena, productora de toxina Shiga, y de adherencia difusa. Con base en estudios que reportan la presencia de E. coli productora de toxina Shiga y E. coli enteroagregativa en carnes y vegetales en supermercados, se cree que productos alimentarios contaminados contribuyen a la transmisión de estos patógenos y a la infección del huésped susceptible. Más estudios son necesarios para evaluar los mecanismos de transmisión, el impacto en la epidemiologia de la EDA, y las pautas de manejo y prevención de estos patógenos que afectan la población pediátrica en Colombia. PMID:25491457

  3. Application of Semi-analytical Satellite Theory orbit propagator to orbit determination for space object catalog maintenance

    Science.gov (United States)

    Setty, Srinivas J.; Cefola, Paul J.; Montenbruck, Oliver; Fiedler, Hauke

    2016-05-01

    Catalog maintenance for Space Situational Awareness (SSA) demands an accurate and computationally lean orbit propagation and orbit determination technique to cope with the ever increasing number of observed space objects. As an alternative to established numerical and analytical methods, we investigate the accuracy and computational load of the Draper Semi-analytical Satellite Theory (DSST). The standalone version of the DSST was enhanced with additional perturbation models to improve its recovery of short periodic motion. The accuracy of DSST is, for the first time, compared to a numerical propagator with fidelity force models for a comprehensive grid of low, medium, and high altitude orbits with varying eccentricity and different inclinations. Furthermore, the run-time of both propagators is compared as a function of propagation arc, output step size and gravity field order to assess its performance for a full range of relevant use cases. For use in orbit determination, a robust performance of DSST is demonstrated even in the case of sparse observations, which is most sensitive to mismodeled short periodic perturbations. Overall, DSST is shown to exhibit adequate accuracy at favorable computational speed for the full set of orbits that need to be considered in space surveillance. Along with the inherent benefits of a semi-analytical orbit representation, DSST provides an attractive alternative to the more common numerical orbit propagation techniques.

  4. On the Theory and Numerical Simulation of Cohesive Crack Propagation with Application to Fiber-Reinforced Composites

    Science.gov (United States)

    Rudraraju, Siva Shankar; Garikipati, Krishna; Waas, Anthony M.; Bednarcyk, Brett A.

    2013-01-01

    The phenomenon of crack propagation is among the predominant modes of failure in many natural and engineering structures, often leading to severe loss of structural integrity and catastrophic failure. Thus, the ability to understand and a priori simulate the evolution of this failure mode has been one of the cornerstones of applied mechanics and structural engineering and is broadly referred to as "fracture mechanics." The work reported herein focuses on extending this understanding, in the context of through-thickness crack propagation in cohesive materials, through the development of a continuum-level multiscale numerical framework, which represents cracks as displacement discontinuities across a surface of zero measure. This report presents the relevant theory, mathematical framework, numerical modeling, and experimental investigations of through-thickness crack propagation in fiber-reinforced composites using the Variational Multiscale Cohesive Method (VMCM) developed by the authors.

  5. Application of the Gaussian beam summation method to the study of the ultrasonic wave propagation in a turbulent medium; Application de la methode de sommation de faisceaux gaussiens a l`etude de la propagation ultrasonore en milieu turbulent

    Energy Technology Data Exchange (ETDEWEB)

    Fiorina, D

    1998-01-29

    Some systems for the control and the surveillance of fast reactors are based on the characteristics of the ultrasonic wave propagation. We present here the results of a numerical and experimental study of ultrasonic propagation in a thermal turbulent medium. A numerical model, based on the technique of superposition of discrete Fourier modes for representing isotropic and homogeneous turbulence and on the Gaussian beam summation method for calculating the acoustic field, has been implemented in order to study the propagation of a point source wave in a bidimensional turbulent medium. Our model is based on the following principle: the medium is represented by a great number of independent realizations of a turbulent field and for each of them we calculate the acoustic field in a deterministic way. Statistics over a great number of realizations enable us to access to the different quantities of the distorted acoustic field: variance of the time of flight fluctuations, scintillation index and intensity probability density function. In the case of small fluctuations, the results for these three quantities are in a good agreement with analytical solutions. When the level of the fluctuations grows, the model predicts correct evolutions. However, a great sensitivity to the location of a receiver in the vicinity of a caustic has been proved. Calculations in the temporal domain have also been performed. They give an illustration of the possible effects of the turbulence on an impulsion signal. An experimental device, fitted with thermocouples and acoustic transducers, has been used to study the ultrasonic propagation in turbulent water. The different measures permitted to characterize the turbulent field and to get aware of the effect of the turbulence on the acoustic propagation. The acoustical measures agree well with the analytical solution of Chernov and Rytov. They are show the importance of the knowledge of the real spectrum of the fluctuations and the limitations of

  6. Propagation of waves

    CERN Document Server

    David, P

    2013-01-01

    Propagation of Waves focuses on the wave propagation around the earth, which is influenced by its curvature, surface irregularities, and by passage through atmospheric layers that may be refracting, absorbing, or ionized. This book begins by outlining the behavior of waves in the various media and at their interfaces, which simplifies the basic phenomena, such as absorption, refraction, reflection, and interference. Applications to the case of the terrestrial sphere are also discussed as a natural generalization. Following the deliberation on the diffraction of the "ground? wave around the ear

  7. Review of complex networks application in hydroclimatic extremes with an implementation to characterize spatio-temporal drought propagation in continental USA

    Science.gov (United States)

    Konapala, Goutam; Mishra, Ashok

    2017-12-01

    The quantification of spatio-temporal hydroclimatic extreme events is a key variable in water resources planning, disaster mitigation, and preparing climate resilient society. However, quantification of these extreme events has always been a great challenge, which is further compounded by climate variability and change. Recently complex network theory was applied in earth science community to investigate spatial connections among hydrologic fluxes (e.g., rainfall and streamflow) in water cycle. However, there are limited applications of complex network theory for investigating hydroclimatic extreme events. This article attempts to provide an overview of complex networks and extreme events, event synchronization method, construction of networks, their statistical significance and the associated network evaluation metrics. For illustration purpose, we apply the complex network approach to study the spatio-temporal evolution of droughts in Continental USA (CONUS). A different drought threshold leads to a new drought event as well as different socio-economic implications. Therefore, it would be interesting to explore the role of thresholds on spatio-temporal evolution of drought through network analysis. In this study, long term (1900-2016) Palmer drought severity index (PDSI) was selected for spatio-temporal drought analysis using three network-based metrics (i.e., strength, direction and distance). The results indicate that the drought events propagate differently at different thresholds associated with initiation of drought events. The direction metrics indicated that onset of mild drought events usually propagate in a more spatially clustered and uniform approach compared to onsets of moderate droughts. The distance metric shows that the drought events propagate for longer distance in western part compared to eastern part of CONUS. We believe that the network-aided metrics utilized in this study can be an important tool in advancing our knowledge on drought

  8. The proton-coupled amino acid transporter hPAT1 is the main transporter involved in vigabatrin uptake in intestinal Caco-2 cells

    DEFF Research Database (Denmark)

    Nøhr, Martha Kampp; Hansen, Steen Honore'; Brodin, Birger

    2012-01-01

    transporter hPAT1. The aim of the project was to identify if transporters are involved in cellular uptake of vigabatrin in Caco-2 cells. Methods: The uptake rate of vigabatrin was measured in Caco-2 cells at pH 6.0 or 7.4 for 15 min after application of 0.1 – 25.0 mM vigabatrin. The inhibitory effect...... of selected amino acids and -derivatives on the apical vigabatrin uptake in Caco-2 cells was investigated. Vigabatrin samples were analyzed using liquid chromatography (LC) coupled to a mass selective detector (MSD). Results: The uptake rate of vigabatrin in Caco-2 cells was pH-dependent. The uptake...... of vigabatrin was saturable at pH 6.0 with a Michaelis constant, Km of 12.7 ± 3.7 mM and a maximal flux, Jmax of 3.7 ± 0.5 nmol•min-1•cm-2. The presences of hPAT1 ligands significantly inhibited the uptake of vigabatrin in Caco-2 cells at pH 6.0, whereas hPAT1 non-ligands did not. Discussion: The saturability...

  9. Numerical modelling of fire propagation: principles and applications at Electricite de France; La simulation numerique d`incendie: principe et applications a Electricite de France

    Energy Technology Data Exchange (ETDEWEB)

    Rongere, F X; Gibault, J

    1994-05-01

    Electricite de France, wishing to limit the accidental unavailability of its nuclear plants and to ensure their safety rigorously takes particular care to reduce the risk of fire. In this context, the Heat Transfer and Aerodynamics Branch of the Research and Development Division has been in charge of the design of numerical tools to simulate the fire propagation in buildings since 1985. Its program is articulated towards three axes which include : the development of the MAGIC software program, the characterization of the combustibles present in power plants, the development of methods for the use of the computer codes in the design of plants. This paper gives on overview of the activity in progress in this research fields. It illustrates also the applications performed and anticipated at Electricite de France of the numerical simulation in fire safety design. We discuss at the end of it the limitations and the development factors of these tool use. One of the later is the association of MAGIC software and the FIVE method. (authors). 15 refs., 10 figs., 2 tabs.

  10. An application of nonlinear supratransmission to the propagation of binary signals in weakly damped, mechanical systems of coupled oscillators

    International Nuclear Information System (INIS)

    Macias-Diaz, J.E.; Puri, A.

    2007-01-01

    In the present Letter, we simulate the propagation of binary signals in semi-infinite, mechanical chains of coupled oscillators harmonically driven at the end, by making use of the recently discovered process of nonlinear supratransmission. Our numerical results-which are based on a brand-new computational technique with energy-invariant properties-show an efficient and reliable transmission of information

  11. Acoustic signal propagation and measurement in natural stream channels for application to surrogate bed load measurements: Halfmoon Creek, Colorado

    Science.gov (United States)

    Monitoring sediment-generated noise using submerged hydrophones is a surrogate method for measuring bed load transport in streams with the potential for improving estimates of bed load transport through widespread, inexpensive monitoring. Understanding acoustic signal propagation in natural stream e...

  12. Experimental investigation of the formation and propagation of plasma jets created by a power laser: application to laboratory astrophysics

    International Nuclear Information System (INIS)

    Loupias, B.

    2008-10-01

    Plasma jets are often observed in the polar regions of Young Stellar Objects (YSO). For a better understanding of the whole processes at the origin of their formation and evolution, this research thesis aims at demonstrating the feasibility of a plasma jet generation by a power laser, and at investigating its characteristics. After a detailed description of Young Stellar Objects jets and an overview of theoretical models, the author describes some experiments performed with gas guns, pulsed machines and power lasers. He describes means of generation of a jet by laser interaction via strong shock propagation. He reports experimental work, describing the target, laser operating conditions and the determination of jet parameters: speed, temperature, density. Then, he introduces results obtained for plasma jet propagation in vacuum, describes their evolution with respect to initial conditions (target type, laser operating conditions), and identifies optimal conditions for generating a jet similar to that in astrophysical conditions. He considers their propagation in ambient medium like for YSO jets in interstellar medium. Two distinct cases are investigated: collision of two successive shocks in a gaseous medium, and propagation of a plasma jet in a gas jet

  13. Uniqueness and existence result around lax-milgram lemma: application to electromagnetic waves propagation in tokamak plasmas

    International Nuclear Information System (INIS)

    Sebelin, E.; Peysson, Y.; Litaudon, X.; Moreau, D.

    1997-09-01

    In the context of complex Hilbert spaces is proved, around Lax-Milgram lemma, the existence and uniqueness of solutions associated to a class of stationary variational problems. This result is applied to the study of variational problems from the propagation equation of time-harmonic electromagnetic waves in confined tokamak plasmas. (author)

  14. Uniqueness and existence result around lax-milgram lemma: application to electromagnetic waves propagation in tokamak plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Sebelin, E.; Peysson, Y.; Litaudon, X.; Moreau, D. [Association Euratom-CEA, CEA Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee; Miellou, J.C. [Besancon Univ., 25 (France). Laboratoire d`Analyse Numerique; Lafitte, O. [CEA Limeil, 94 - Villeneuve-Saint-Georges (France)

    1997-09-01

    In the context of complex Hilbert spaces is proved, around Lax-Milgram lemma, the existence and uniqueness of solutions associated to a class of stationary variational problems. This result is applied to the study of variational problems from the propagation equation of time-harmonic electromagnetic waves in confined tokamak plasmas. (author) 21 refs.

  15. Application of the Gaussian beam summation method to the study of the ultrasonic wave propagation in a turbulent medium

    International Nuclear Information System (INIS)

    Fiorina, D.

    1998-01-01

    Some systems for the control and the surveillance of fast reactors are based on the characteristics of the ultrasonic wave propagation. We present here the results of a numerical and experimental study of ultrasonic propagation in a thermal turbulent medium. A numerical model, based on the technique of superposition of discrete Fourier modes for representing isotropic and homogeneous turbulence and on the Gaussian beam summation method for calculating the acoustic field, has been implemented in order to study the propagation of a point source wave in a bidimensional turbulent medium. Our model is based on the following principle: the medium is represented by a great number of independent realizations of a turbulent field and for each of them we calculate the acoustic field in a deterministic way. Statistics over a great number of realizations enable us to access to the different quantities of the distorted acoustic field: variance of the time of flight fluctuations, scintillation index and intensity probability density function. In the case of small fluctuations, the results for these three quantities are in a good agreement with analytical solutions. When the level of the fluctuations grows, the model predicts correct evolutions. However, a great sensitivity to the location of a receiver in the vicinity of a caustic has been proved. Calculations in the temporal domain have also been performed. They give an illustration of the possible effects of the turbulence on an impulsion signal. An experimental device, fitted with thermocouples and acoustic transducers, has been used to study the ultrasonic propagation in turbulent water. The different measures permitted to characterize the turbulent field and to get aware of the effect of the turbulence on the acoustic propagation. The acoustical measures agree well with the analytical solution of Chernov and Rytov. They are show the importance of the knowledge of the real spectrum of the fluctuations and the limitations of

  16. Assessment of family psychosocial functioning in survivors of pediatric cancer using the PAT2.0.

    Science.gov (United States)

    Gilleland, Jordan; Reed-Knight, Bonney; Brand, Sarah; Griffin, Anya; Wasilewski-Masker, Karen; Meacham, Lillian; Mertens, Ann

    2013-09-01

    This study aimed to examine clinical validity and utility of a screening measure for familial psychosocial risk, the Psychosocial Assessment Tool 2.0 (PAT2.0), among pediatric cancer survivors participating in long-term survivorship care. Caregivers (N=79) completed the PAT2.0 during their child's survivorship appointment. Caregivers also reported on family engagement in outpatient mental health treatment. Medical records were reviewed for treatment history and oncology provider initiated psychology consults. The internal consistency of the PAT2.0 total score in this survivorship sample was strong. Psychology was consulted by the oncology provider to see 53% of participant families, and families seen by psychology had significantly higher PAT2.0 total scores than families without psychology consults. PAT2.0 total scores and corresponding subscales were higher for patients, parents, and siblings enrolled in outpatient mental health services since treatment completion. Results were consistent with psychosocial risk categories presented within the Pediatric Psychosocial Preventative Health Model. Fifty-one percent of families presenting for survivorship care scored in the "universal" category, 34% scored in the "targeted" category, and 15% scored in the "clinical" category. Data indicate that the overall proportions of families experiencing "universal", "targeted", and "clinical" levels of familial distress may be constant from the time of diagnosis into survivorship care. Overall, the PAT2.0 demonstrated strong psychometric properties among survivors of pediatric cancer and shows promise as a psychosocial screening measure to facilitate more effective family support in survivorship care. Copyright © 2013 John Wiley & Sons, Ltd.

  17. The effects of PAT on the Savannah River ecosystem, particularly fisheries

    Energy Technology Data Exchange (ETDEWEB)

    Patrick, R.

    1994-03-01

    The main purpose of this study was to determine whether or not the pre-startup activities at K-Reactor, i.e., Power Ascension Testing (PAT), have caused damage because of temperature rises in the Savannah River. Therefore, the biological studies were mainly aimed at providing information as to changes that might cause the damage of the fish population, and to other important organisms in the ecosystem. To determine if deleterious effects had occurred, one had to review the past studies to determine the condition and diversity of aquatic life before these PAT studies started. Therefore old reports were reviewed and a current study made in 1992.

  18. Crystallization and preliminary X-ray diffraction analysis of PAT, an acetyltransferase from Sulfolobus solfataricus

    International Nuclear Information System (INIS)

    Cho, Ching-Chang; Luo, Ching-Wei; Hsu, Chun-Hua

    2008-01-01

    PAT, an acetyltransferase from the archaeon S. solfataricus that specifically acetylates the chromatin protein Alba, was expressed, purified and crystallized. PAT is an acetyltransferase from the archaeon Sulfolobus solfataricus that specifically acetylates the chromatin protein Alba. The enzyme was expressed, purified and subsequently crystallized using the sitting-drop vapour-diffusion technique. Native diffraction data were collected to 1.70 Å resolution on the BL13C1 beamline of NSRRC from a flash-frozen crystal at 100 K. The crystals belonged to space group P2 1 2 1 2 1 , with unit-cell parameters a = 44.30, b = 46.59, c = 68.39 Å

  19. Strategic framework for education and training in Quality by Design (QbD) and process analytical technology (PAT)

    DEFF Research Database (Denmark)

    de Matas, Marcel; De Beer, Thomas; Folestad, Staffan

    2016-01-01

    is not prescriptive and is not aimed at describing specific course content in detail. It should however be used as a point of reference for those institutions delivering pharmaceutical based educational courses, to ensure that the necessary skills, knowledge and experience for successful pharmaceutical development...... advanced science and technology coupled with the application of modern Quality by Design (QbD) principles. In order that Europe keeps pace with these changes and sustains its position as major player in the development and commercialization of medicines, it is essential that measures are put in place...... to maintain a highly skilled workforce. A number of challenges however exist to equipping academic, industrial and health agency staff with the requisite knowledge, skills and experience to develop the next generation of medicines. In this regard, the EUFEPS QbD and PAT Sciences Network has proposed...

  20. Project PAT (Pumps Working as Turbines)/IG (Induction Generators): a new concept for generation of electric power through micro scale hydroelectric power plants; Projeto BFT (Bombas Funcionado como Turbinas)/GI (Geradores de Inducao): um novo conceito para geracao de energia eletrica atraves de microcentrais hidreletricas

    Energy Technology Data Exchange (ETDEWEB)

    Viana, Augusto Nelson Carvalho [Universidade Federal de Itajuba (UNIFEI), Itajuba, MG (Brazil). Inst. de Recursos Naturais. Programa de Pos-graduacao em Engenharia da Energia; Medeiros, Daniel de Macedo; Ricardo, Mateus [Universidade Federal de Itajuba (UNIFEI), Itajuba, MG (Brazil). Inst. de Recursos Naturais], Emails: augusto@unifei.edu.br, macedo@unifei.edu.br, mathidr@yahoo.com.br

    2006-07-01

    The present work has as objective to present the main bases of 'PAT/IG Project', accomplished in Boa Esperanca Farm (Delfim Moreira - MG), by an accord between Itajuba's Federal University and Mines and Energy Ministry. In a moment that the look for sustainable development is the law in Brazil, low costs and environmental impact alternatives must be prioritized. By this way, the PAT/IG Project continuous the Viana's (1987) works, that developed all Brazilian theoretical bases for using Pumps Working as Turbine (PAT). Besides that, the application of induction motors operating as induction generators will be evaluated, as the velocity control system of the PAT/IG group will be developed. The existing Boa Esperanca Farm's micro power plant will be rebuild ed, to receive a new generating group formed for a PAT and a IG, that will be used as natural sized test workbench of Itajuba's Federal University. At the ending of the project, there will be enough subsidies to prove, in practice, the feasibility presented in laboratorial tests by PAT/IG groups as conventional turbines replacer in micro powerplants. (author)

  1. Project PAT (Pumps Working as Turbines)/IG (Induction Generators): a new concept for generation of electric power through micro scale hydroelectric power plants; Projeto BFT (Bombas Funcionado como Turbinas)/GI (Geradores de Inducao): um novo conceito para geracao de energia eletrica atraves de microcentrais hidreletricas

    Energy Technology Data Exchange (ETDEWEB)

    Viana, Augusto Nelson Carvalho [Universidade Federal de Itajuba (UNIFEI), Itajuba, MG (Brazil). Inst. de Recursos Naturais. Programa de Pos-graduacao em Engenharia da Energia; Medeiros, Daniel de Macedo; Ricardo, Mateus [Universidade Federal de Itajuba (UNIFEI), Itajuba, MG (Brazil). Inst. de Recursos Naturais], Emails: augusto@unifei.edu.br, macedo@unifei.edu.br, mathidr@yahoo.com.br

    2006-07-01

    The present work has as objective to present the main bases of 'PAT/IG Project', accomplished in Boa Esperanca Farm (Delfim Moreira - MG), by an accord between Itajuba's Federal University and Mines and Energy Ministry. In a moment that the look for sustainable development is the law in Brazil, low costs and environmental impact alternatives must be prioritized. By this way, the PAT/IG Project continuous the Viana's (1987) works, that developed all Brazilian theoretical bases for using Pumps Working as Turbine (PAT). Besides that, the application of induction motors operating as induction generators will be evaluated, as the velocity control system of the PAT/IG group will be developed. The existing Boa Esperanca Farm's micro power plant will be rebuild ed, to receive a new generating group formed for a PAT and a IG, that will be used as natural sized test workbench of Itajuba's Federal University. At the ending of the project, there will be enough subsidies to prove, in practice, the feasibility presented in laboratorial tests by PAT/IG groups as conventional turbines replacer in micro powerplants. (author)

  2. Transfer function of multimode fiber links using an electric field propagation model: Application to Radio over Fibre Systems.

    Science.gov (United States)

    Gasulla, I; Capmany, J

    2006-10-02

    We present a closed-form expression for the evaluation of the transfer function of a multimode fiber (MMF) link based on the electric field propagation model. After validating the result we investigate the potential for broadband transmission in regions far from baseband. We find that MMFs offer the potential for broadband ROF transmission in the microwave and millimetre wave regions in short and middle reach distances.

  3. Contribution to the determination of the double angular and energy differential neutron albedo. Application to the propagation in lacunar medium

    International Nuclear Information System (INIS)

    Litaize, O.

    2000-01-01

    The goal of this thesis is to study the neutron propagation by reflection from lacunar medium interfaces. The most efficient method to calculate this type of propagation is to use the concept of albedo. Actual version of NARCISSE code uses a simple formulation of angular differential albedos and so, can only treat single reflections. Multiple reflections treatment needs the knowledge of neutron spectrum after reflection. This energetic information is contained in double angular and energy differential albedos. The first step of this study consists to generate these albedos for various materials. Several methods have been tested and the Monte Carlo method was retained. A new estimator has been developed and validated in the Mote Carlo transport code TRIPOLI-4. It computes, during the simulation of the neutron history, the angular and energy reflection probability at each collision site. The second step consists to generate an interpolation scheme and albedo libraries for various materials. A new version of NARCISSE was developed to use these libraries and the interpolation module. Spectrum and dose rates comparisons were made between codes to validate these albedos. The neutron propagation by multiple reflections can be studied now, by using this new version of Narcisse. (author)

  4. Propagation of uncertainties through the oil spill model MEDSLIK-II: operational application to the Black Sea

    Science.gov (United States)

    Liubartseva, Svitlana; Coppini, Giovanni; Ciliberti, Stefania Angela; Lecci, Rita

    2017-04-01

    In operational oil spill modeling, MEDSLIK-II (De Dominicis et al., 2013) focuses on the reliability of the oil drift and fate predictions routinely fed by operational oceanographic and atmospheric forecasting chain. Uncertainty calculations enhance oil spill forecast efficiency, supplying probability maps to quantify the propagation of various uncertainties. Recently, we have developed the methodology that allows users to evaluate the variability of oil drift forecast caused by uncertain data on the initial oil spill conditions (Liubartseva et al., 2016). One of the key methodological aspects is a reasonable choice of a way of parameter perturbation. In case of starting oil spill location and time, these scalars might be treated as independent random parameters. If we want to perturb the underlying ocean currents and wind, we have to deal with deterministic vector parameters. To a first approximation, we suggest rolling forecasts as a set of perturbed ocean currents and wind. This approach does not need any extra hydrodynamic calculations, and it is quick enough to be performed in web-based applications. The capabilities of the proposed methodology are explored using the Black Sea Forecasting System (BSFS) recently implemented by Ciliberti et al. (2016) for the Copernicus Marine Environment Monitoring Service (http://marine.copernicus.eu/services-portfolio/access-to-products). BSFS horizontal resolution is 1/36° in zonal and 1/27° in meridional direction (ca. 3 km). Vertical domain discretization is represented by 31 unevenly spaced vertical levels. Atmospheric wind data are provided by the European Centre for Medium-Range Weather Forecasts (ECMWF) forecasts, at 1/8° (ca. 12.5 km) horizontal and 6-hour temporal resolution. A great variety of probability patterns controlled by different underlying flows is represented including the cyclonic Rim Current, flow bifurcations in anticyclonic eddies (e.g., Sevastopol and Batumi), northwestern shelf circulation, etc

  5. Low propagation loss in a one-port SAW resonator fabricated on single-crystal diamond for super-high-frequency applications.

    Science.gov (United States)

    Fujii, Satoshi; Odawara, Tatsuya; Yamada, Haruya; Omori, Tatsuya; Hashimoto, Ken-Ya; Torii, Hironori; Umezawa, Hitoshi; Shikata, Shinichi

    2013-05-01

    Diamond has the highest known SAW phase velocity, sufficient for applications in the gigahertz range. However, although numerous studies have demonstrated SAW devices on polycrystalline diamond thin films, all have had much larger propagation loss than single-crystal materials such as LiNbO3. Hence, in this study, we fabricated and characterized one-port SAW resonators on single-crystal diamond substrates synthesized using a high-pressure and high-temperature method to identify and minimize sources of propagation loss. A series of one-port resonators were fabricated with the interdigital transducer/ AlN/diamond structure and their characteristics were measured. The device with the best performance exhibited a resonance frequency f of 5.3 GHz, and the equivalent circuit model gave a quality factor Q of 5509. Thus, a large fQ product of approximately 2.9 × 10(13) was obtained, and the propagation loss was found to be only 0.006 dB/wavelength. These excellent properties are attributed mainly to the reduction of scattering loss in a substrate using a single-crystal diamond, which originated from the grain boundary of diamond and the surface roughness of the AlN thin film and the diamond substrate. These results show that single-crystal diamond SAW resonators have great potential for use in low-noise super-high-frequency oscillators.

  6. Mycobacterium chelonae y Mycobacterium abscessus: patógenos emergentes

    Directory of Open Access Journals (Sweden)

    Mónica M. Ortegón

    1996-09-01

    Full Text Available Mycobacterium chelonae es el nombre correcto para la micobacteria aislada en 1903 de los pulmones enfermos de una tortuga marina. En una especie distinta de Mycobacterium fo/tuitum, aislado de ranas en 1905, y de Mycobacterium abscessus, considerado actualmente como una subespecie de M chelonae. Estas tres especies son las únicas patógenas para el hombre dentro del grupo de micobacterias ambientales o atipicas, de crecimiento rápido, las cuales se caracterizan por formar colonias en cultivo en menos de siete días. Son agentes etiológicos de nódulos y abscesos cutáneos, localizados y diseminados, de lesiones postoperatorias, usualmente en la cicatriz quirúrgica, de lesiones pulmonares y de linfadenitis granulomatosa, de osteomielitis y de queratitis, entre otras. Las lesiones cutáneas y de los tejidos blandos son las más frecuentes y resultan generalmente de la inoculación traumática de esta micobacteria. Histopatológicamente, los nódulos y abscesos muestran un proceso inflamatorio, supurativo y granulomatoso, mixto, en el que en la cuarta parte de los casos pueden demostrarse conglomerados de bacilos ácido alcohol resistentes, que tienden a estar situados en una vacuola en el centro del absceso. En Colombia, se han descrito tres brotes de abscesos subcutáneos producidos por bacterias ambientales, secundarios a la aplicación de inyecciones contaminadas con el germen causal: en 1981, en Bucaramanga, luego de la aplicación de la vacuna contra la fiebre amarilla, en 50 personas, la mayoría niños; en 1989, en Medellin, por la inyección subcutánea de alergenos, en 13 personas; y, en 1993, en varias ciudades de la costa atlántica, luego de aplicaciones subcutáneas de xilocaína, como tratamiento bionergético, en 297 pacientes. Existen otros informes aislados de casos posttraumáticos.La enfermedad diseminada por micobacterias de rápido crecimiento, se presenta en pacientes inmunosuprimidos. En la biopsia, predominan los

  7. PAT1 (SLC36A1) shows nuclear localization and affect growth of smooth muscle cells from rats

    DEFF Research Database (Denmark)

    Jensen, Anne; Figueiredo-Larsen, Evan Manuel; Holm, René

    2014-01-01

    The proton-coupled amino acid transporter 1 (PAT1) is a transporter of amino acids in small intestinal enterocytes. PAT1 is, however, also capable of regulating cell growth and sensing the availability of amino acids in other cell types. The aim of the present study was to investigate the localiz...

  8. Designing Robust Process Analytical Technology (PAT) Systems for Crystallization Processes: A Potassium Dichromate Crystallization Case Study

    DEFF Research Database (Denmark)

    Abdul Samad, Noor Asma Fazli Bin; Sin, Gürkan

    2013-01-01

    The objective of this study is to test and validate a Process Analytical Technology (PAT) system design on a potassium dichromate crystallization process in the presence of input uncertainties using uncertainty and sensitivity analysis. To this end a systematic framework for managing uncertaintie...

  9. Mecanismos de defensa en las interacciones planta-patógeno

    DEFF Research Database (Denmark)

    Madriz-Ordeñana, Kenneth

    1998-01-01

    ésto. Las in- teracciones planta-patógeno pueden presentar varios tipos de asociaciones, que dependen en gran parte del contenido genético de cada organismo. La resistencia inducida es una forma de defensa activa que involucra la expresión diferencial de genes y cambios metabólicos que ocurren como...

  10. Teacher's PAT? Multiple-Role Principal-Agent Theory, Education Politics, and Bureaucrat Power

    Science.gov (United States)

    Vanhuysse, Pieter; Sulitzeanu-Kenan, Raanan

    2009-01-01

    This article aims to contribute to current debates about political power and agency relationships in education and other public sectors. In a recent clarion call for a major redirection of political principal-agent theories (PAT), Terry Moe has argued that standard information asymmetries ought no longer to be regarded as the sole foundation of…

  11. Patógenos introducidos al Perú en post larvas de Litopenaeus vannamei importadas

    Directory of Open Access Journals (Sweden)

    Mervin Guevara

    2012-11-01

    Full Text Available El comercio internacional de animales acuáticos es uno de los factores más importantes en la introducción involuntaria de patógenos a una región libre de estos. Los patógenos introducidos han sido causa de enormes pérdidas económicas en organismos bajo cultivo y daños ecológicos en poblaciones silvestres. En este trabajo, utilizando la técnica de la PCR se analizaron postlarvas de Litopenaeus vannamei importadas desde Ecuador para ser utilizada en los cultivos de langostinos en Tumbes. La finalidad fue detectar patógenos como el virus de la mancha blanca (WSV, virus de la cabeza amarilla (YHV, virus de la necrosis hipodérmica y hematopoyética infecciosa (IHHNV, Baculovirus penaei (BP, virus del síndrome de Taura (TSV y la bacteria de la hepatopancreatitis necrotizante (NHPB. Se analizaron 177 muestras de postlarvas en el año 2009 y 274 en el 2010. En el año 2009 se encontraron cuatro patógenos infecciosos en las postlarvas analizadas, siendo más frecuente el IHHNV (9,60%. En el año 2010 la frecuencia de aparición de postlarvas infectadas con IHHNV fue mayor (16,79%. Tanto en el 2009 como en el 2010 se encontraron postlarvas positivas a NHPB, BP y TSV

  12. Evaluation of the EndoPAT as a Tool to Assess Endothelial Function

    Directory of Open Access Journals (Sweden)

    M. Moerland

    2012-01-01

    Endothelial function was stable over a longer period of time in renally impaired patients (coefficient of variation 13%. Endothelial function in renally impaired and type 2 diabetic patients was not decreased compared to healthy volunteers (2.9±1.4 and 1.8±0.3, resp., versus 1.8±0.5, P>0.05. The EndoPAT did not detect an effect of robust interventions on endothelial function in healthy volunteers (glucose load: change from baseline 0.08±0.50, 95% confidence interval −0.44 to 0.60; smoking: change from baseline 0.49±0.92, 95% confidence interval −0.47 to 1.46. This suggests that at present the EndoPAT might not be suitable to assess (changes in endothelial function in early-phase clinical pharmacology studies. Endothelial function as measured by the EndoPAT could be physiologically different from endothelial function as measured by conventional techniques. This should be investigated carefully before the EndoPAT can be considered a useful tool in drug development or clinical practice.

  13. Investigating Trauma in Narrating World War I: A Psychoanalytical Reading of Pat Barker's "Regeneration"

    Science.gov (United States)

    Sadjadi, Bakhtiar; Esmkhani, Farnaz

    2016-01-01

    The present paper seeks to critically read Pat Barker's "Regeneration" in terms of Cathy Caruth's psychoanalytic study of trauma. This analysis attempts to trace the concepts of latency, post-traumatic stress disorders, traumatic memory, and trauma in Barker's novel in order to explore how trauma and history are interrelated in the…

  14. Design and Fabrication of Cryostat Interface and Electronics for High Performance Antimatter Trap (HI-PAT)

    Science.gov (United States)

    Smith, Gerald A.

    1999-01-01

    Included in Appendix I to this report is a complete set of design and assembly schematics for the high vacuum inner trap assembly, cryostat interfaces and electronic components for the MSFC HI-PAT. Also included in the final report are summaries of vacuum tests, and electronic tests performed upon completion of the assembly.

  15. Application of a Hybrid Method Combining Grey Model and Back Propagation Artificial Neural Networks to Forecast Hepatitis B in China

    Directory of Open Access Journals (Sweden)

    Ruijing Gan

    2015-01-01

    Full Text Available Accurate incidence forecasting of infectious disease provides potentially valuable insights in its own right. It is critical for early prevention and may contribute to health services management and syndrome surveillance. This study investigates the use of a hybrid algorithm combining grey model (GM and back propagation artificial neural networks (BP-ANN to forecast hepatitis B in China based on the yearly numbers of hepatitis B and to evaluate the method’s feasibility. The results showed that the proposal method has advantages over GM (1, 1 and GM (2, 1 in all the evaluation indexes.

  16. Application of a hybrid method combining grey model and back propagation artificial neural networks to forecast hepatitis B in china.

    Science.gov (United States)

    Gan, Ruijing; Chen, Xiaojun; Yan, Yu; Huang, Daizheng

    2015-01-01

    Accurate incidence forecasting of infectious disease provides potentially valuable insights in its own right. It is critical for early prevention and may contribute to health services management and syndrome surveillance. This study investigates the use of a hybrid algorithm combining grey model (GM) and back propagation artificial neural networks (BP-ANN) to forecast hepatitis B in China based on the yearly numbers of hepatitis B and to evaluate the method's feasibility. The results showed that the proposal method has advantages over GM (1, 1) and GM (2, 1) in all the evaluation indexes.

  17. Non linear shock wave propagation in heterogeneous fluids: a numerical approach beyond the parabolic approximation with application to sonic boom.

    Science.gov (United States)

    Dagrau, Franck; Coulouvrat, François; Marchiano, Régis; Héron, Nicolas

    2008-06-01

    Dassault Aviation as a civil aircraft manufacturer is studying the feasibility of a supersonic business jet with the target of an "acceptable" sonic boom at the ground level, and in particular in case of focusing. A sonic boom computational process has been performed, that takes into account meteorological effects and aircraft manoeuvres. Turn manoeuvres and aircraft acceleration create zones of convergence of rays (caustics) which are the place of sound amplification. Therefore two elements have to be evaluated: firstly the geometrical position of the caustics, and secondly the noise level in the neighbourhood of the caustics. The modelling of the sonic boom propagation is based essentially on the assumptions of geometrical acoustics. Ray tracing is obtained according to Fermat's principle as paths that minimise the propagation time between the source (the aircraft) and the receiver. Wave amplitude and time waveform result from the solution of the inviscid Burgers' equation written along each individual ray. The "age variable" measuring the cumulative nonlinear effects is linked to the ray tube area. Caustics are located as the place where the ray tube area vanishes. Since geometrical acoustics does not take into account diffraction effects, it breaks down in the neighbourhood of caustics where it would predict unphysical infinite pressure amplitude. The aim of this study is to describe an original method for computing the focused noise level. The approach involves three main steps that can be summarised as follows. The propagation equation is solved by a forward marching procedure split into three successive steps: linear propagation in a homogeneous medium, linear perturbation due to the weak heterogeneity of the medium, and non-linear effects. The first step is solved using an "exact" angular spectrum algorithm. Parabolic approximation is applied only for the weak perturbation due to the heterogeneities. Finally, non linear effects are performed by solving the

  18. Computation of Propagation Speed and Reflection of Axially Symmetric Waves in Composite Cylinders, with Application to Impedance Tube and Calibrator.

    Science.gov (United States)

    1982-08-25

    hoth real and complex; and () compute the propagation speed in the acoustic cal Ibr:ator. (continued on reverse) DD IARM3 1473 EDITION OF I NOVSSIS...FORMAT (3F15.0) 0131 GO TO 230 0132 690 CONTINUE 0133 END 50 *> SUBROUTINES SUBROUTINE: DET C C SUBROUTINE DET C DECEMBER, 1980 C EDITED BY TINA RUGGIERO...33 AISA =AKDA/BAMS 0008 02A=AKA**’-AKDA**2 0009 S2A=AKA**2-AKSA**2 0010 IF (RHM) 65P65P40 0011 40 AKFA-AKDA/COCD 0012 OF2A-AKA**2-AKFA**2 0013 IF (OF2A

  19. Strategic framework for education and training in Quality by Design (QbD) and process analytical technology (PAT).

    Science.gov (United States)

    de Matas, Marcel; De Beer, Thomas; Folestad, Staffan; Ketolainen, Jarkko; Lindén, Hans; Lopes, João Almeida; Oostra, Wim; Weimer, Marco; Öhrngren, Per; Rantanen, Jukka

    2016-07-30

    The regulatory and technical landscape of the pharmaceutical field is rapidly evolving from one focused predominantly on development of small molecules, using well established manufacturing technologies towards an environment in which biologicals and complex modalities are being developed using advanced science and technology coupled with the application of modern Quality by Design (QbD) principles. In order that Europe keeps pace with these changes and sustains its position as major player in the development and commercialization of medicines, it is essential that measures are put in place to maintain a highly skilled workforce. A number of challenges however exist to equipping academic, industrial and health agency staff with the requisite knowledge, skills and experience to develop the next generation of medicines. In this regard, the EUFEPS QbD and PAT Sciences Network has proposed a structured framework for education, training and continued professional development, which comprises a number of pillars covering the fundamental principles of modern pharmaceutical development including the underpinning aspects of science, engineering and technology innovation. The framework is not prescriptive and is not aimed at describing specific course content in detail. It should however be used as a point of reference for those institutions delivering pharmaceutical based educational courses, to ensure that the necessary skills, knowledge and experience for successful pharmaceutical development are maintained. A positive start has been made and a number of examples of formal higher education courses and short training programs containing elements of this framework have been described. The ultimate vision for this framework however, is to see widespread adoption and proliferation of this curriculum with it forming the backbone of QbD and PAT science based skills development. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Propagation of shock waves in elastic solids caused by cavitation microjet impact. II: Application in extracorporeal shock wave lithotripsy.

    Science.gov (United States)

    Zhong, P; Chuong, C J; Preminger, G M

    1993-07-01

    To better understand the mechanism of stone fragmentation during extracorporeal shock wave lithotripsy (ESWL), the model developed in Part I [P. Zhong and C.J. Chuong, J. Acoust. Soc. Am. 94, 19-28 (1993)] is applied to study cavitation microjet impingement and its resultant shock wave propagation in renal calculi. Impact pressure at the stone boundary and stress, strain at the propagating shock fronts in the stone were calculated for typical ESWL loading conditions. At the anterior surface of the stone, the jet induced compressive stress can vary from 0.82 approximately 4 times that of the water hammer pressure depending on the contact angles; whereas the jet-induced shear stress can achieve its maximum, with a magnitude of 30% approximately 54% of the water hammer pressure, near the detachment of the longitudinal (or P) wave in the solid. Comparison of model predictions with material failure strengths of renal calculi suggests that jet impact can lead to stone surface erosion by combined compressive and shear loadings at the jet impacting surface, and spalling failure by tensile forces at the distal surface of the stone. Comparing responses from four different stone types suggests that cystine is the most difficult stone to fragment in ESWL, as observed from clinical experience.

  1. Comparison of Different Approaches to Predict the Performance of Pumps As Turbines (PATs

    Directory of Open Access Journals (Sweden)

    Mauro Venturini

    2018-04-01

    Full Text Available This paper deals with the comparison of different methods which can be used for the prediction of the performance curves of pumps as turbines (PATs. The considered approaches are four, i.e., one physics-based simulation model (“white box” model, two “gray box” models, which integrate theory on turbomachines with specific data correlations, and one “black box” model. More in detail, the modeling approaches are: (1 a physics-based simulation model developed by the same authors, which includes the equations for estimating head, power, and efficiency and uses loss coefficients and specific parameters; (2 a model developed by Derakhshan and Nourbakhsh, which first predicts the best efficiency point of a PAT and then reconstructs their complete characteristic curves by means of two ad hoc equations; (3 the prediction model developed by Singh and Nestmann, which predicts the complete turbine characteristics based on pump shape and size; (4 an Evolutionary Polynomial Regression model, which represents a data-driven hybrid scheme which can be used for identifying the explicit mathematical relationship between PAT and pump curves. All approaches are applied to literature data, relying on both pump and PAT performance curves of head, power, and efficiency over the entire range of operation. The experimental data were provided by Derakhshan and Nourbakhsh for four different turbomachines, working in both pump and PAT mode with specific speed values in the range 1.53–5.82. This paper provides a quantitative assessment of the predictions made by means of the considered approaches and also analyzes consistency from a physical point of view. Advantages and drawbacks of each method are also analyzed and discussed.

  2. iPat: intelligent prediction and association tool for genomic research.

    Science.gov (United States)

    Chen, Chunpeng James; Zhang, Zhiwu

    2018-06-01

    The ultimate goal of genomic research is to effectively predict phenotypes from genotypes so that medical management can improve human health and molecular breeding can increase agricultural production. Genomic prediction or selection (GS) plays a complementary role to genome-wide association studies (GWAS), which is the primary method to identify genes underlying phenotypes. Unfortunately, most computing tools cannot perform data analyses for both GWAS and GS. Furthermore, the majority of these tools are executed through a command-line interface (CLI), which requires programming skills. Non-programmers struggle to use them efficiently because of the steep learning curves and zero tolerance for data formats and mistakes when inputting keywords and parameters. To address these problems, this study developed a software package, named the Intelligent Prediction and Association Tool (iPat), with a user-friendly graphical user interface. With iPat, GWAS or GS can be performed using a pointing device to simply drag and/or click on graphical elements to specify input data files, choose input parameters and select analytical models. Models available to users include those implemented in third party CLI packages such as GAPIT, PLINK, FarmCPU, BLINK, rrBLUP and BGLR. Users can choose any data format and conduct analyses with any of these packages. File conversions are automatically conducted for specified input data and selected packages. A GWAS-assisted genomic prediction method was implemented to perform genomic prediction using any GWAS method such as FarmCPU. iPat was written in Java for adaptation to multiple operating systems including Windows, Mac and Linux. The iPat executable file, user manual, tutorials and example datasets are freely available at http://zzlab.net/iPat. zhiwu.zhang@wsu.edu.

  3. Sound propagation in narrow tubes including effects of viscothermal and turbulent damping with application to charge air coolers

    Science.gov (United States)

    Knutsson, Magnus; Åbom, Mats

    2009-02-01

    Charge air coolers (CACs) are used on turbocharged internal combustion engines to enhance the overall gas-exchange performance. The cooling of the charged air results in higher density and thus volumetric efficiency. It is also important for petrol engines that the knock margin increases with reduced charge air temperature. A property that is still not very well investigated is the sound transmission through a CAC. The losses, due to viscous and thermal boundary layers as well as turbulence, in the narrow cooling tubes result in frequency dependent attenuation of the transmitted sound that is significant and dependent on the flow conditions. Normally, the cross-sections of the cooling tubes are neither circular nor rectangular, which is why no analytical solution accounting for a superimposed mean flow exists. The cross-dimensions of the connecting tanks, located on each side of the cooling tubes, are large compared to the diameters of the inlet and outlet ducts. Three-dimensional effects will therefore be important at frequencies significantly lower than the cut-on frequencies of the inlet/outlet ducts. In this study the two-dimensional finite element solution scheme for sound propagation in narrow tubes, including the effect of viscous and thermal boundary layers, originally derived by Astley and Cummings [Wave propagation in catalytic converters: Formulation of the problem and finite element scheme, Journal of Sound and Vibration 188 (5) (1995) 635-657] is used to extract two-ports to represent the cooling tubes. The approximate solutions for sound propagation, accounting for viscothermal and turbulent boundary layers derived by Dokumaci [Sound transmission in narrow pipes with superimposed uniform mean flow and acoustic modelling of automobile catalytic converters, Journal of Sound and Vibration 182 (5) (1995) 799-808] and Howe [The damping of sound by wall turbulent shear layers, Journal of the Acoustical Society of America 98 (3) (1995) 1723-1730], are

  4. Application of Self-Propagating High Temperature Synthesis to the Fabrication of Actinide Bearing Nitride and Other Ceramic Nuclear Fuels

    International Nuclear Information System (INIS)

    Moore, John J.; Reigel, Marissa M.; Donohoue, Collin D.

    2009-01-01

    The project uses an exothermic combustion synthesis reaction, termed self-propagating high-temperature synthesis (SHS), to produce high quality, reproducible nitride fuels and other ceramic type nuclear fuels (cercers and cermets, etc.) in conjunction with the fabrication of transmutation fuels. The major research objective of the project is determining the fundamental SHS processing parameters by first using manganese as a surrogate for americium to produce dense Zr-Mn-N ceramic compounds. These fundamental principles will then be transferred to the production of dense Zr-Am-N ceramic materials. A further research objective in the research program is generating fundamental SHS processing data to the synthesis of (i) Pu-Am-Zr-N and (ii) U-Pu-Am-N ceramic fuels. In this case, Ce will be used as the surrogate for Pu, Mn as the surrogate for Am, and depleted uranium as the surrogate for U. Once sufficient fundamental data has been determined for these surrogate systems, the information will be transferred to Idaho National Laboratory (INL) for synthesis of Zr-Am-N, Pu-Am-Zr-N and U-Pu-Am-N ceramic fuels. The high vapor pressures of americium (Am) and americium nitride (AmN) are cause for concern in producing nitride ceramic nuclear fuel that contains Am. Along with the problem of Am retention during the sintering phases of current processing methods, are additional concerns of producing a consistent product of desirable homogeneity, density and porosity. Similar difficulties have been experienced during the laboratory scale process development stage of producing metal alloys containing Am wherein compact powder sintering methods had to be abandoned. Therefore, there is an urgent need to develop a low-temperature or low-heat fuel fabrication process for the synthesis of Am-containing ceramic fuels. Self-propagating high temperature synthesis (SHS), also called combustion synthesis, offers such an alternative process for the synthesis of Am nitride fuels. Although SHS

  5. Method of moving frames to solve time-dependent Maxwell's equations on anisotropic curved surfaces: Applications to invisible cloak and ELF propagation

    Science.gov (United States)

    Chun, Sehun

    2017-07-01

    Applying the method of moving frames to Maxwell's equations yields two important advancements for scientific computing. The first is the use of upwind flux for anisotropic materials in Maxwell's equations, especially in the context of discontinuous Galerkin (DG) methods. Upwind flux has been available only to isotropic material, because of the difficulty of satisfying the Rankine-Hugoniot conditions in anisotropic media. The second is to solve numerically Maxwell's equations on curved surfaces without the metric tensor and composite meshes. For numerical validation, spectral convergences are displayed for both two-dimensional anisotropic media and isotropic spheres. In the first application, invisible two-dimensional metamaterial cloaks are simulated with a relatively coarse mesh by both the lossless Drude model and the piecewisely-parametered layered model. In the second application, extremely low frequency propagation on various surfaces such as spheres, irregular surfaces, and non-convex surfaces is demonstrated.

  6. Ratiometric highly sensitive luminescent nanothermometers working in the room temperature range. Applications to heat propagation in nanofluids

    Science.gov (United States)

    Brites, Carlos D. S.; Lima, Patrícia P.; Silva, Nuno J. O.; Millán, Angel; Amaral, Vitor S.; Palacio, Fernando; Carlos, Luís D.

    2013-07-01

    There is an increasing demand for accurate, non-invasive and self-reference temperature measurements as technology progresses into the nanoscale. This is particularly so in micro- and nanofluidics where the comprehension of heat transfer and thermal conductivity mechanisms can play a crucial role in areas as diverse as energy transfer and cell physiology. Here we present two luminescent ratiometric nanothermometers based on a magnetic core coated with an organosilica shell co-doped with Eu3+ and Tb3+ chelates. The design of the hybrid host and chelate ligands permits the working of the nanothermometers in a nanofluid at 293-320 K with an emission quantum yield of 0.38 +/- 0.04, a maximum relative sensitivity of 1.5% K-1 at 293 K and a spatio-temporal resolution (constrained by the experimental setup) of 64 × 10-6 m/150 × 10-3 s (to move out of 0.4 K - the temperature uncertainty). The heat propagation velocity in the nanofluid, (2.2 +/- 0.1) × 10-3 m s-1, was determined at 294 K using the nanothermometers' Eu3+/Tb3+ steady-state spectra. There is no precedent of such an experimental measurement in a thermographic nanofluid, where the propagation velocity is measured from the same nanoparticles used to measure the temperature.There is an increasing demand for accurate, non-invasive and self-reference temperature measurements as technology progresses into the nanoscale. This is particularly so in micro- and nanofluidics where the comprehension of heat transfer and thermal conductivity mechanisms can play a crucial role in areas as diverse as energy transfer and cell physiology. Here we present two luminescent ratiometric nanothermometers based on a magnetic core coated with an organosilica shell co-doped with Eu3+ and Tb3+ chelates. The design of the hybrid host and chelate ligands permits the working of the nanothermometers in a nanofluid at 293-320 K with an emission quantum yield of 0.38 +/- 0.04, a maximum relative sensitivity of 1.5% K-1 at 293 K and a spatio

  7. Propagation of epithermal neutrons in the empty mesh of the EDF3 reactor. Application of Zeus IV

    International Nuclear Information System (INIS)

    Brisbois, Jacques; Sonnet, Alain; Rafalovitch, Armand

    1969-10-01

    The authors report the verification of the Zeus 4 Monte Carlo code by applying it to an actual example of neutron propagation in a large enclosure, the empty mesh of the EDF3 reactor, supplied through the box holes (for the passage of heat transfer fluid ducts). This enclosure is represented by 105 parallelepipedic meshes in which are placed 4 plane and square sources of same cross section as the holes, and emitting inwards in cos θ. Source intensity is determined by flow rate measurements during tests in the air, interpreted by a Zeus-based calculation and channel power measurements during a 387 MW level operation. The presence of ducts is taken into account by applying a global attenuation coefficient to the sources. Calculation and experiment results agree very well in view of geometry complexity [fr

  8. Dictionary Learning on the Manifold of Square Root Densities and Application to Reconstruction of Diffusion Propagator Fields*

    Science.gov (United States)

    Sun, Jiaqi; Xie, Yuchen; Ye, Wenxing; Ho, Jeffrey; Entezari, Alireza; Blackband, Stephen J.

    2013-01-01

    In this paper, we present a novel dictionary learning framework for data lying on the manifold of square root densities and apply it to the reconstruction of diffusion propagator (DP) fields given a multi-shell diffusion MRI data set. Unlike most of the existing dictionary learning algorithms which rely on the assumption that the data points are vectors in some Euclidean space, our dictionary learning algorithm is designed to incorporate the intrinsic geometric structure of manifolds and performs better than traditional dictionary learning approaches when applied to data lying on the manifold of square root densities. Non-negativity as well as smoothness across the whole field of the reconstructed DPs is guaranteed in our approach. We demonstrate the advantage of our approach by comparing it with an existing dictionary based reconstruction method on synthetic and real multi-shell MRI data. PMID:24684004

  9. AISLAMIENTO Y CARACTERIZACIÓN MORFOLÓGICA DE Rosellinia pepo Pat. EN PLANTAS DE MACADAMIA ISOLATION AND MORPHOLOGICAL CHARACTERIZATION OF Rosellinia pepo Pat. IN MACADAMIA PLANTS

    Directory of Open Access Journals (Sweden)

    Carmen Eliana Realpe Ortiz

    2006-12-01

    Full Text Available El hongo Rosellinia pepo Pat., causante de la llaga estrellada, se considera uno de los principales problemas fitosanitarios de la macadamia por ocasionar la muerte de la planta en su etapa productiva. Debido a que no existe una metodología de aislamiento confiable que asegure la recuperación del hongo con un porcentaje mínimo de contaminación y los estudios relacionados con este patógeno son escasos se planteó una investigación con el fin de perfeccionar una metodología de aislamiento y realizar algunas caracterizaciones morfológicas de este patógeno. La nueva metodología permitió obtener aislamientos con un 91,26% de pureza del hongo. La tasa de crecimiento fue de 4,68 mm día-1. Las colonias son de color blanco y apariencia algodonosa en su inicio, pero a medida que envejece el micelio toma un color café o negro y su apariencia se torna quebradiza. La observación de micelio blanco en forma de estrella en el lado interior del medio sintético permite diferenciarlo de otras especies como R. bunodes. Las mediciones microscópicas de los hinchamientos piriformes presentaron en promedio 106,4mm de largo y 75,3mm de ancho. Este trabajo también permitió determinar el nivel de inóculo infectivo.The fungus Rosellinia pepo Pat, the causal agent of star gall, is considered to be a main phytosanitary problem to the Macademia tree by causing the death of the tree while in its productive stage. Because no reliable isolation method exists that assures recovery of the mushroom with a minimum percentage of contamination and studies of this pathogen are scarce. This study was conducted to perfect an isolation methodology and permit some morphological characterizations of this pathogen. The new methodology allowed isolations with 91,26% purity of mushroom to be obtained. The rate of growth was 4,68 mm day-1. The colonies were of white color and cottony appearance in the beginning, but as the micelio aged it assumed a brown or black color and a

  10. Uncertainty propagation by using spectral methods: A practical application to a two-dimensional turbulence fluid model

    Science.gov (United States)

    Riva, Fabio; Milanese, Lucio; Ricci, Paolo

    2017-10-01

    To reduce the computational cost of the uncertainty propagation analysis, which is used to study the impact of input parameter variations on the results of a simulation, a general and simple to apply methodology based on decomposing the solution to the model equations in terms of Chebyshev polynomials is discussed. This methodology, based on the work by Scheffel [Am. J. Comput. Math. 2, 173-193 (2012)], approximates the model equation solution with a semi-analytic expression that depends explicitly on time, spatial coordinates, and input parameters. By employing a weighted residual method, a set of nonlinear algebraic equations for the coefficients appearing in the Chebyshev decomposition is then obtained. The methodology is applied to a two-dimensional Braginskii model used to simulate plasma turbulence in basic plasma physics experiments and in the scrape-off layer of tokamaks, in order to study the impact on the simulation results of the input parameter that describes the parallel losses. The uncertainty that characterizes the time-averaged density gradient lengths, time-averaged densities, and fluctuation density level are evaluated. A reasonable estimate of the uncertainty of these distributions can be obtained with a single reduced-cost simulation.

  11. Nonlinear Propagation of Alfven Waves Driven by Observed Photospheric Motions: Application to the Coronal Heating and Spicule Formation

    Science.gov (United States)

    Matsumoto, Takuma; Shibata, Kazunari

    We have performed MHD simulations of Alfven wave propagation along an open ux tube in the solar atmosphere. In our numerical model, Alfven waves are generated by the photospheric granular motion. As the wave generator, we used a derived temporal spectrum of the photo-spheric granular motion from G-band movies of Hinode/SOT. It is shown that the total energy ux at the corona becomes larger and the transition region height becomes higher in the case when we use the observed spectrum rather than white/pink noise spectrum as the wave gener-ator. This difference can be explained by the Alfven wave resonance between the photosphere and the transition region. After performing Fourier analysis on our numerical results, we have found that the region between the photosphere and the transition region becomes an Alfven wave resonant cavity. We have conrmed that there are at least three resonant frequencies, 1, 3 and 5 mHz, in our numerical model. Alfven wave resonance is one of the most effective mechanisms to explain the dynamics of the spicules and the sufficient energy ux to heat the corona.

  12. PAT-2 (Plutonium Air-Transportable Model 2) safety analysis report

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, J.A.; Davis, E.J.; Duffey, T.A.; Dupree, S.A.; George, O.L. Jr.; Ortiz, Z.

    1981-07-01

    The PAT-2 package is designed for the safe transport of plutonium and/or uranium in small quantities. The PAT-2 package is resistant to severe accidents, including that of a high-speed jet aircraft crash, and is designed to withstand such environments as extreme impact, crushing, puncturing and slashing loads, severe hydrocarbon-fueled fires, and deep underwater immersion, with no escape of contents. The package meets the requirements of 10 CFR 71 for Fissile Class I packages with a cargo of 15 grams of Pu-239, or other isotopic forms described herein, not to exceed 2 watts of thermal activity. This SAR presents design and oprational information including evaluations and analyses, test results, operating procedures, maintenance, and quality assurance information.

  13. PAT-2 (Plutonium Air-Transportable Model 2) safety analysis report

    International Nuclear Information System (INIS)

    Andersen, J.A.; Davis, E.J.; Duffey, T.A.; Dupree, S.A.; George, O.L. Jr.; Ortiz, Z.

    1981-07-01

    The PAT-2 package is designed for the safe transport of plutonium and/or uranium in small quantities. The PAT-2 package is resistant to severe accidents, including that of a high-speed jet aircraft crash, and is designed to withstand such environments as extreme impact, crushing, puncturing and slashing loads, severe hydrocarbon-fueled fires, and deep underwater immersion, with no escape of contents. The package meets the requirements of 10 CFR 71 for Fissile Class I packages with a cargo of 15 grams of Pu-239, or other isotopic forms described herein, not to exceed 2 watts of thermal activity. This SAR presents design and oprational information including evaluations and analyses, test results, operating procedures, maintenance, and quality assurance information

  14. PAT and SEM study of porous silicon formed by anodization methods

    International Nuclear Information System (INIS)

    Liu Jian; Wei Long; Wang Huiyao; Ma Chuangxin; Wang Baoyi

    2000-01-01

    The porous silicon formed by anodization of crystal silicon was studied by positron annihilation technique (PAT) and scanning electron microscopy (SEM). The PAT experiments showed that the mean life and vacancy defects increased with the increasing anodization time. While the intensities of the longest lifetime, several ns-tens ns (ortho-positronium) dropped down. Small single-crystal Si spheres with mean radius of a few μm were observed by SEM after anodization. Pits with mean radius of a few μm from the divorcement of single-crystal spheres were also observed after further anodization. The increases of vacancy defects might be that the extension of structures of porous silicon towards inner layer with anodization time and caused more vacancy defects in inner layer. The SEM observation presented another possibility of the increase of density of vacancy defects in surface layer induced by the change of structures

  15. Quantifying Beetle-Mediated Effects on Gas Fluxes from Dung Pats

    Science.gov (United States)

    Penttilä, Atte; Slade, Eleanor M.; Simojoki, Asko; Riutta, Terhi; Minkkinen, Kari; Roslin, Tomas

    2013-01-01

    Agriculture is one of the largest contributors of the anthropogenic greenhouse gases (GHGs) responsible for global warming. Measurements of gas fluxes from dung pats suggest that dung is a source of GHGs, but whether these emissions are modified by arthropods has not been studied. A closed chamber system was used to measure the fluxes of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) from dung pats with and without dung beetles on a grass sward. The presence of dung beetles significantly affected the fluxes of GHGs from dung pats. Most importantly, fresh dung pats emitted higher amounts of CO2 and lower amounts of CH4 per day in the presence than absence of beetles. Emissions of N2O showed a distinct peak three weeks after the start of the experiment – a pattern detected only in the presence of beetles. When summed over the main grazing season (June–July), total emissions of CH4 proved significantly lower, and total emissions of N2O significantly higher in the presence than absence of beetles. While clearly conditional on the experimental conditions, the patterns observed here reveal a potential impact of dung beetles on gas fluxes realized at a small spatial scale, and thereby suggest that arthropods may have an overall effect on gas fluxes from agriculture. Dissecting the exact mechanisms behind these effects, mapping out the range of conditions under which they occur, and quantifying effect sizes under variable environmental conditions emerge as key priorities for further research. PMID:23940758

  16. Topology optimization of wave-propagation problems

    DEFF Research Database (Denmark)

    Jensen, Jakob Søndergaard; Sigmund, Ole

    2006-01-01

    Topology optimization is demonstrated as a useful tool for systematic design of wave-propagation problems. We illustrate the applicability of the method for optical, acoustic and elastic devices and structures.......Topology optimization is demonstrated as a useful tool for systematic design of wave-propagation problems. We illustrate the applicability of the method for optical, acoustic and elastic devices and structures....

  17. X-PAT: a multiplatform patient referral data management system for small healthcare institution requirements.

    Science.gov (United States)

    Masseroli, Marco; Marchente, Mario

    2008-07-01

    We present X-PAT, a platform-independent software prototype that is able to manage patient referral multimedia data in an intranet network scenario according to the specific control procedures of a healthcare institution. It is a self-developed storage framework based on a file system, implemented in eXtensible Markup Language (XML) and PHP Hypertext Preprocessor Language, and addressed to the requirements of limited-dimension healthcare entities (small hospitals, private medical centers, outpatient clinics, and laboratories). In X-PAT, healthcare data descriptions, stored in a novel Referral Base Management System (RBMS) according to Health Level 7 Clinical Document Architecture Release 2 (CDA R2) standard, can be easily applied to the specific data and organizational procedures of a particular healthcare working environment thanks also to the use of standard clinical terminology. Managed data, centralized on a server, are structured in the RBMS schema using a flexible patient record and CDA healthcare referral document structures based on XML technology. A novel search engine allows defining and performing queries on stored data, whose rapid execution is ensured by expandable RBMS indexing structures. Healthcare personnel can interface the X-PAT system, according to applied state-of-the-art privacy and security measures, through friendly and intuitive Web pages that facilitate user acceptance.

  18. El sistema ubicuitina/proteasoma en la interacción planta-patógeno

    Directory of Open Access Journals (Sweden)

    Mario Rocha-Sosa

    2013-01-01

    Full Text Available La ubicuitina (Ub es una proteína pequeña la cual es utilizada por los organismos eucariontes para marcar proteínas, en la mayoría de los casos para que éstas sean posteriormente degradadas. La ubicuitinación ocurre en tres pasos sucesivos los cuales requieren de la acción de una enzima activadora, una enzima conjugadora y una ligasa de Ub. Una vez ubicuitinada la proteína seguirá un destino diferente de acuerdo a la topología de la ubicuitinación. Muchas de las proteínas marcadas por ubicuitinación serán degradadas por un complejo proteínico de 2.5 Mda conocido como el proteasoma 26S. Las plantas emplean ampliamente este mecanismo de degradación regulada de proteínas para modular procesos de crecimiento y desarrollo o bien, para responder ante situaciones adversas como puede ser una baja disponibilidad de agua o el ataque por patógenos. Durante la evolución las plantas han desarrollado diversas estrategias para defenderse ante la agresión por patógenos, sin embargo, estos organismos han logrado implementar herramientas que les permiten contrarrestar los mecanismos de defensa de las plantas, entre otras formas, los patógenos han logrado manipular el sistema Ub/proteasoma para poder infectarlas eficientemente.

  19. Patērētāju attieksme pret zīmolu "IKEA"

    OpenAIRE

    Aleksejenko, Dana

    2014-01-01

    Tēma ir “Patērētāju attieksme pret zīmolu “IKEA””.Pētījuma mērķis ir noskaidrot Latvijas iedzīvotāju, “IKEA” zīmola patērētāju un mazumtirgotāju viedokli, attieksmi un vērtējumu par zīmolu “IKEA”.Radošā daļa ir pamatota ar teorētisko daļu par:zīmola jēdzienu, patērētāju uzvedību, mārketinga komunikāciju un uzņēmumu internetā. Apakašnodaļās ir aprakstīta zīmola identitāte un zīmola vērtība, korporatīvais zīmols un korporatīvā identitāte.Metodoloģija ir izstrādāta vairākās pakāpēs,katras pakāpe...

  20. Ion Storage Tests with the High Performance Antimatter Trap (HiPAT)

    Science.gov (United States)

    Martin, James J.; Lewis, Raymond A.; Chakrabarti, Suman; Pearson, Boise; Schafer, Charles (Technical Monitor)

    2002-01-01

    The NASA/Marshall Space Flight Centers (NASA/MSFC) Propulsion Research Center (PRC) is evaluating an antiproton storage system, referred to as the High Performance Antiproton Trap (HiPAT). This interest stems from the sheer energy represented by matter/antimatter annihilation process with has an energy density approximately 10 order of magnitude above that of chemical propellants. In other terms, one gram of antiprotons contains the equivalent energy of approximately 23 space shuttle external tanks or ET's (each ET contains roughly 740,000 kgs of fuel and oxidizer). This incredible source of stored energy, if harnessed, would be an enabling technology for deep space mission where both spacecraft weight and propulsion performance are key to satisfying aggressive mission requirements. The HiPAT hardware consists of a 4 Tesla superconductor system, an ultra high vacuum test section (vacuum approaching 10(exp -12) torr), and a high voltage confinement electrode system (up to 20 kvolts operation). The current laboratory layout is illustrated. The HiPAT designed objectives included storage of up to 1 trillion antiprotons with corresponding lifetimes approaching 18 days. To date, testing has centered on the storage of positive hydrogen ions produced in situ by a stream of high-energy electrons that passes through the trapping region. However, due to space charge issues and electron beam compression as it passes through the HiPAT central field, current ion production is limited to less then 50,000 ions. Ion lifetime was determined by counting particle populations at the end of various storage time intervals. Particle detection was accomplished by destructively expelling the ions against a micro-channel plate located just outside the traps magnetic field. The effect of radio frequency (RF) stabilization on the lifetime of trapped particles was also examined. This technique, referred to as a rotating wall, made use of a segmented electrode located near the center of the trap

  1. Expression of PAT and NPT II proteins during the developmental stages of a genetically modified pepper developed in Korea.

    Science.gov (United States)

    Kim, Hyo Jin; Lee, Si Myung; Kim, Jae Kwang; Ryu, Tae Hun; Suh, Seok Cheol; Cho, Hyun Suk

    2010-10-27

    Estimation of the protein levels introduced in a biotechnology-derived product is conducted as part of an overall safety assessment. An enzyme-linked immunosorbent assay (ELISA) was used to analyze phosphinothricin acetyltransferase (PAT) and neomycin phosphotransferase II (NPT II) protein expression in a genetically modified (GM) pepper plant developed in Korea. PAT and NPT II expression levels, based on both dry weight and fresh weight, were variable among different plant generations and plant sections from isolated genetically modified organism (GMO) fields at four developmental stages. PAT expression was highest in leaves at anthesis (11.44 μg/gdw and 2.17 μg/gfw) and lowest in roots (0.12 μg/gdw and 0.01 μg/gfw). NPT II expression was also highest in leaves at anthesis (17.31 μg/gdw and 3.41 μg/gfw) and lowest in red pepper (0.65 μg/gdw and 0.12 μg/gfw). In pollen, PAT expression was 0.59-0.62 μg/gdw, while NPT II was not detected. Both PAT and NPT II showed a general pattern of decreased expression with progression of the growing season. As expected, PAT and NPT II protein expression was not detectable in control pepper plants.

  2. Radio wave propagation and parabolic equation modeling

    CERN Document Server

    Apaydin, Gokhan

    2018-01-01

    A thorough understanding of electromagnetic wave propagation is fundamental to the development of sophisticated communication and detection technologies. The powerful numerical methods described in this book represent a major step forward in our ability to accurately model electromagnetic wave propagation in order to establish and maintain reliable communication links, to detect targets in radar systems, and to maintain robust mobile phone and broadcasting networks. The first new book on guided wave propagation modeling and simulation to appear in nearly two decades, Radio Wave Propagation and Parabolic Equation Modeling addresses the fundamentals of electromagnetic wave propagation generally, with a specific focus on radio wave propagation through various media. The authors explore an array of new applications, and detail various v rtual electromagnetic tools for solving several frequent electromagnetic propagation problems. All of the methods described are presented within the context of real-world scenari...

  3. Microorganismos patógenos y potencialmente patógenos en secreciones genitales de gestantes a término asociados a complicaciones posnatales

    Directory of Open Access Journals (Sweden)

    Tania Castellanos Medina

    2013-09-01

    Full Text Available Introducción: tanto las infecciones puerperales como las neonatales precoces reflejan probablemente los microorganismos que están presentes en la vagina en el período cercano al parto. Objetivo: establecer la relación entre los microorganismos identificados en las secreciones genitales de las gestantes a término y el desarrollo de sepsis neonatal y puerperal, así como vincular dichas complicaciones con los agentes diagnosticados. Métodos: se realizó un estudio longitudinal y prospectivo en los servicios de microbiología, obstetricia, perinatología y neonatología del Hospital General Docente "Dr. "Juan Bruno Zayas Alfonso", de Santiago de Cuba, desde julio de 2009 hasta marzo de 2010. Se identificaron microorganismos en 179 muestras cervicovaginales, las cuales fueron procesadas en el laboratorio de microbiología según las normas vigentes. Resultados: los microorganismos más identificados resultaron los géneros Mycoplasmas y Chlamydias (78,2 y 69,3%, respectivamente y fueron los que con mayor frecuencia se asociaron. Un porcentaje elevado de las gestantes (67,0 %, tenía más de un agente en sus secreciones genitales. Después del parto hubo un hallazgo mayor de infecciones en el producto de la concepción (21,8 % que en las puérperas (3,9% y la mayoría de estas complicaciones se relacionaron con la presencia de 2 o más microorganismos. Conclusiones: las asociaciones de microorganismos patógenos o potencialmente patógenos en las secreciones genitales de embarazadas a término, aumentan el riesgo de complicaciones posnatales.

  4. Identification of acoustic wave propagation in a duct line and its application to detection of impact source location based on signal processing

    International Nuclear Information System (INIS)

    Shin, Yong Woo; Kim, Min Soo; Lee, Sang Kwon

    2010-01-01

    For the detection of the impact location in a pipeline system, the correlation method has been the conventional method. For the application of the correlation method, the diameter of a duct should be small so that the acoustic wave inside the duct can propagate with nondispersive characteristics, in the form of, for example, a plane wave. This correlation method calculates the cross-correlation between acoustic waves measured at two acceleration sensors attached to a buried duct. It also gives information about the arrival time delay of an acoustic wave between two sensors. These arrival time delays are used for the estimation of the impact location. However, when the diameter of the duct is large, the acoustic waves inside the duct propagate with dispersive characteristics owing to the reflection of the acoustic wave off of the wall of the duct. This dispersive characteristic is related to the acoustic modes inside a duct. Therefore, the correlation method does not work correctly for the detection of the impact location. This paper proposes new methods of accurately measuring the arrival time delay between two sensors attached to duct line system. This method is based on the time-frequency analyses of the short time Fourier transform (STFT) and continuous wavelet transform (CWT). These methods can discriminate direct waves (non-dispersive waves) and reflective waves (dispersive waves) from the measured wave signals through the time-frequency analysis. The direct wave or the reflective wave is used to estimate the arrival time delay. This delay is used for the identification of the impact location. This systematic method can predict the impact location due to the impact forces of construction equipment with more accuracy than the correlation method

  5. Semiclassical propagation of Wigner functions.

    Science.gov (United States)

    Dittrich, T; Gómez, E A; Pachón, L A

    2010-06-07

    We present a comprehensive study of semiclassical phase-space propagation in the Wigner representation, emphasizing numerical applications, in particular as an initial-value representation. Two semiclassical approximation schemes are discussed. The propagator of the Wigner function based on van Vleck's approximation replaces the Liouville propagator by a quantum spot with an oscillatory pattern reflecting the interference between pairs of classical trajectories. Employing phase-space path integration instead, caustics in the quantum spot are resolved in terms of Airy functions. We apply both to two benchmark models of nonlinear molecular potentials, the Morse oscillator and the quartic double well, to test them in standard tasks such as computing autocorrelation functions and propagating coherent states. The performance of semiclassical Wigner propagation is very good even in the presence of marked quantum effects, e.g., in coherent tunneling and in propagating Schrodinger cat states, and of classical chaos in four-dimensional phase space. We suggest options for an effective numerical implementation of our method and for integrating it in Monte-Carlo-Metropolis algorithms suitable for high-dimensional systems.

  6. A novel contra propagating ultrasonic flowmeter using glad buffer rods for high temperature measurement. Application to the oil and gas industries

    Energy Technology Data Exchange (ETDEWEB)

    Franca, Demartonne R. [Brasilia Univ., DF (Brazil). Dept. de Engenharia Eletrica; Cheng-Kuei Jen; Yuu Ono [National Research Council (NRC), Quebec (Canada). Industrial Materials Institute

    2005-07-01

    Ultrasonic techniques are attractive for process monitoring and control because they are non-intrusive, robust and inexpensive. Two common concerns limiting the high temperature performance of conventional ultrasonic systems for flow measurement are related to transducers and couplants. A suitable approach to overcoming this drawback is to insert a thermal isolating buffer rod with good ultrasonic performance (e.g., high signal-to-noise ratio). This requirement is important because, a priori, the noises generated in the buffer rod may bury the desired signals, so that no meaningful information is extracted. Besides protecting the ultrasonic transducers from overheating in applications such as high temperature flow measurements, buffer rods are also a solution for the couplant between the probe and tested sample, since their probing end can be directly wetted by fluids. Here, we propose clad buffer rods driven by shear transducers as the main building block of contra propagating ultrasonic flowmeters for high temperature application. It is demonstrated that the superior signal-to-noise ratio exhibit by clad buffer rods compared to the reported non-clad counterparts improve precision in transit-time measurement, leading to more accurate flow speed determination. In addition, it is shown that clad buffer rods generate specific ultrasonic signals for temperature calibration of flowmeters, allowing temperature variation while still measuring accurately the flow speed. These results are of interest for the oil and gas industries. (author)

  7. Propagation of dynamic measurement uncertainty

    International Nuclear Information System (INIS)

    Hessling, J P

    2011-01-01

    The time-dependent measurement uncertainty has been evaluated in a number of recent publications, starting from a known uncertain dynamic model. This could be defined as the 'downward' propagation of uncertainty from the model to the targeted measurement. The propagation of uncertainty 'upward' from the calibration experiment to a dynamic model traditionally belongs to system identification. The use of different representations (time, frequency, etc) is ubiquitous in dynamic measurement analyses. An expression of uncertainty in dynamic measurements is formulated for the first time in this paper independent of representation, joining upward as well as downward propagation. For applications in metrology, the high quality of the characterization may be prohibitive for any reasonably large and robust model to pass the whiteness test. This test is therefore relaxed by not directly requiring small systematic model errors in comparison to the randomness of the characterization. Instead, the systematic error of the dynamic model is propagated to the uncertainty of the measurand, analogously but differently to how stochastic contributions are propagated. The pass criterion of the model is thereby transferred from the identification to acceptance of the total accumulated uncertainty of the measurand. This increases the relevance of the test of the model as it relates to its final use rather than the quality of the calibration. The propagation of uncertainty hence includes the propagation of systematic model errors. For illustration, the 'upward' propagation of uncertainty is applied to determine if an appliance box is damaged in an earthquake experiment. In this case, relaxation of the whiteness test was required to reach a conclusive result

  8. Fracture mechanical modeling of brittle crack propagation and arrest of steel. 3. Application to duplex-type test; Kozai no zeisei kiretsu denpa teisi no rikigaku model. 3. Konseigata shiken eno tekiyo

    Energy Technology Data Exchange (ETDEWEB)

    Aihara, S.; Tsuchida, Y. [Nippon Steel Corp., Tokyo (Japan); Machida, S.; Yoshinari, H. [The University of Tokyo, Tokyo (Japan). Faculty of Engineering

    1996-12-31

    A proposal was made previously on a model of brittle crack propagation and arrest that considers the effect of crack opening suppression by using unbroken ligaments generated on steel plate surface and the effect that cracks precede in the central part of the plate thickness, based on a local limit stress theory for brittleness fracture. This paper discusses applicability of this model to a mixed type test, and elucidates causes for difference in the arrest tenacity of both types in a double tensile test of the standard size. The brittle crack propagation and arrest model based on the local limit stress theory was found applicable to a simulation of the mixed type test. Experimental crack propagation speed history and behavior of the arrest were reproduced nearly completely by using this model. When load stress is increased, the arrests in the mixed type test may be classified into arrests of both inside the steel plate and near the surface, cracks in the former position or arrest in the latter position, and rush of cracks into both positions. Furthermore, at higher stresses, the propagation speed drops once after cracks rushed into the test plate, but turns to a rise, leading to propagation and piercing. 8 refs., 15 figs., 3 tabs.

  9. Fracture mechanical modeling of brittle crack propagation and arrest of steel. 3. Application to duplex-type test; Kozai no zeisei kiretsu denpa teisi no rikigaku model. 3. Konseigata shiken eno tekiyo

    Energy Technology Data Exchange (ETDEWEB)

    Aihara, S; Tsuchida, Y [Nippon Steel Corp., Tokyo (Japan); Machida, S; Yoshinari, H [The University of Tokyo, Tokyo (Japan). Faculty of Engineering

    1997-12-31

    A proposal was made previously on a model of brittle crack propagation and arrest that considers the effect of crack opening suppression by using unbroken ligaments generated on steel plate surface and the effect that cracks precede in the central part of the plate thickness, based on a local limit stress theory for brittleness fracture. This paper discusses applicability of this model to a mixed type test, and elucidates causes for difference in the arrest tenacity of both types in a double tensile test of the standard size. The brittle crack propagation and arrest model based on the local limit stress theory was found applicable to a simulation of the mixed type test. Experimental crack propagation speed history and behavior of the arrest were reproduced nearly completely by using this model. When load stress is increased, the arrests in the mixed type test may be classified into arrests of both inside the steel plate and near the surface, cracks in the former position or arrest in the latter position, and rush of cracks into both positions. Furthermore, at higher stresses, the propagation speed drops once after cracks rushed into the test plate, but turns to a rise, leading to propagation and piercing. 8 refs., 15 figs., 3 tabs.

  10. A Performance Prediction Method for Pumps as Turbines (PAT Using a Computational Fluid Dynamics (CFD Modeling Approach

    Directory of Open Access Journals (Sweden)

    Emma Frosina

    2017-01-01

    Full Text Available Small and micro hydropower systems represent an attractive solution for generating electricity at low cost and with low environmental impact. The pump-as-turbine (PAT approach has promise in this application due to its low purchase and maintenance costs. In this paper, a new method to predict the inverse characteristic of industrial centrifugal pumps is presented. This method is based on results of simulations performed with commercial three-dimensional Computational Fluid Dynamics (CFD software. Model results have been first validated in pumping mode using data supplied by pump manufacturers. Then, the results have been compared to experimental data for a pump running in reverse. Experimentation has been performed on a dedicated test bench installed in the Department of Civil Construction and Environmental Engineering of the University of Naples Federico II. Three different pumps, with different specific speeds, have been analyzed. Using the model results, the inverse characteristic and the best efficiency point have been evaluated. Finally, results have been compared to prediction methods available in the literature.

  11. Multi-parameter flow cytometry as a process analytical technology (PAT) approach for the assessment of bacterial ghost production.

    Science.gov (United States)

    Langemann, Timo; Mayr, Ulrike Beate; Meitz, Andrea; Lubitz, Werner; Herwig, Christoph

    2016-01-01

    Flow cytometry (FCM) is a tool for the analysis of single-cell properties in a cell suspension. In this contribution, we present an improved FCM method for the assessment of E-lysis in Enterobacteriaceae. The result of the E-lysis process is empty bacterial envelopes-called bacterial ghosts (BGs)-that constitute potential products in the pharmaceutical field. BGs have reduced light scattering properties when compared with intact cells. In combination with viability information obtained from staining samples with the membrane potential-sensitive fluorescent dye bis-(1,3-dibutylarbituric acid) trimethine oxonol (DiBAC4(3)), the presented method allows to differentiate between populations of viable cells, dead cells, and BGs. Using a second fluorescent dye RH414 as a membrane marker, non-cellular background was excluded from the data which greatly improved the quality of the results. Using true volumetric absolute counting, the FCM data correlated well with cell count data obtained from colony-forming units (CFU) for viable populations. Applicability of the method to several Enterobacteriaceae (different Escherichia coli strains, Salmonella typhimurium, Shigella flexneri 2a) could be shown. The method was validated as a resilient process analytical technology (PAT) tool for the assessment of E-lysis and for particle counting during 20-l batch processes for the production of Escherichia coli Nissle 1917 BGs.

  12. Greenhouse gas emissions from dung pats vary with dung beetle species and with assemblage composition.

    Directory of Open Access Journals (Sweden)

    Irene Piccini

    Full Text Available Cattle farming is a major source of greenhouse gases (GHGs. Recent research suggests that GHG fluxes from dung pats could be affected by biotic interactions involving dung beetles. Whether and how these effects vary among beetle species and with assemblage composition is yet to be established. To examine the link between GHGs and different dung beetle species assemblages, we used a closed chamber system to measure fluxes of carbon dioxide (CO2, methane (CH4 and nitrous oxide (N2O from cattle dung pats. Targeting a total of four dung beetle species (a pat-dwelling species, a roller of dung balls, a large and a small tunnelling species, we ran six experimental treatments (four monospecific and two mixed and two controls (one with dung but without beetles, and one with neither dung nor beetles. In this setting, the overall presence of beetles significantly affected the gas fluxes, but different species contributed unequally to GHG emissions. When compared to the control with dung, we detected an overall reduction in the total cumulative CO2 flux from all treatments with beetles and a reduction in N2O flux from the treatments with the three most abundant dung beetle species. These reductions can be seen as beneficial ecosystem services. Nonetheless, we also observed a disservice provided by the large tunneler, Copris lunaris, which significantly increased the CH4 flux-an effect potentially traceable to the species' nesting strategy involving the construction of large brood balls. When fluxes were summed into CO2-equivalents across individual GHG compounds, dung with beetles proved to emit less GHGs than did beetle-free dung, with the mix of the three most abundant species providing the highest reduction (-32%. As the mix of multiple species proved the most effective in reducing CO2-equivalents, the conservation of diverse assemblages of dung beetles emerges as a priority in agro-pastoral ecosystems.

  13. Interactions between Upf1 and the decapping factors Edc3 and Pat1 in Saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Kylie D Swisher

    Full Text Available In Saccharomyces cerevisiae, mRNA transcripts with premature termination codons are targeted for deadenylation independent decapping and 5' to 3' decay in a quality control pathway termed nonsense-mediated decay (NMD. Critical factors in NMD include Upf1, Upf2, and Upf3, as well as the decapping enzyme, Dcp2/Dcp1. Loss of Upf2 or Upf3 leads to the accumulation of not only Upf1 and Dcp2 in P-bodies, but also of the decapping-activators Pat1, Dhh1, and Lsm1. An interaction between Upf1 and Dcp2 has been identified, which might recruit Dcp2 to the NMD decapping complex. To determine the nature and significance of the Dcp2-Upf1 interaction, we utilized the yeast two-hybrid assay to assess Upf1 interactions with various mRNA decapping factors. We find that although Dcp2 can interact with Upf1, this interaction is indirect and is largely dependent on the Edc3 protein, which interacts with the N-terminal domain of Upf1 at an overlapping, but not identical, site as Upf2. We also found that Pat1 has an independent two-hybrid interaction with the N-terminus of Upf1. Assessment of both reporter and endogenous NMD transcripts suggest that the decapping stimulators, including Edc3 and Pat1, as well as Edc1 and Edc2, are not essential for NMD under normal conditions. This work defines a larger decapping complex involved in NMD, but indicates that components of that complex are not required for general NMD and might either regulate a subset of NMD transcripts or be essential for proper NMD under different environmental conditions.

  14. Cobre antimicrobiano contra patógenos intrahospitalarios en Perú

    Directory of Open Access Journals (Sweden)

    Edwin Neciosup

    2015-01-01

    Full Text Available Introducción: Las infecciones intrahospitalarias (IIH constituyen un problema de salud pública que generan grandes gastos por parte de los gobiernos, debido a que los patógenos causantes de IIH presentan resistencia a fármacos y generan una mayor permanencia de los pacientes, pues la infraestructura hospitalaria constituye un reservorio favorable para los patógenos. Las superficies de cobre surgen como opción sanitaria y efectiva para controlar el crecimiento y propagación de estos patógenos. Objetivos: Evaluar la actividad bactericida de las superficies de cobre contra los principales bacterias patógenas causantes de IIH (Escherichia coli, Pseudomonas aeruginosa y Staphylococcus aureus. Diseño: Estudio experimental con muestreo no probabilístico. Lugar: Hospital Regional Docente las Mercedes (HRDLM y Hospital Provincial Docente Belén (HPDB, Lambayeque, Perú. Materiales: Nueve cepas bacterianas, 3 de E. coli , 3 de P. aeruginosa y 3 de S. aureus; superficies metálicas (1 cm² de cobre y acero inoxidable (control . Intervenciones: Las 9 cepas bacterianas fueron proporcionadas por los hospitales HRDLM (4 cepas y HPDB (5 cepas. Los análisis de ANOVA y de Tukey fueron aplicados para evaluar la actividad bactericida de las superficies de cobre y acero inoxidable contra las 9 cepas causantes de IIH, usando los programas estadísticos Minitab y Sigmaplot, respectivamente. Principales medidas de resultados: Diferencias en el crecimiento bacteriano sobre superficies de cobre o acero inoxidable, con respecto al tiempo de exposición. Resultados: Las 9 cepas -3 de P. aeruginosa, 3 de E. coli y 3 de S. aureus - expuestas a superficies de cobre fueron eliminadas en 10, 15 y 60 minutos, respectivamente. La carga bacteriana de las células expuestas en superficies de acero inoxidable permaneció constante y viable por periodos mayores a 60 minutos. Además, las superficies de cobre eliminaron más rápido a las bacterias Gram negativas (P

  15. NeuPAT: an intranet database supporting translational research in neuroblastic tumors.

    Science.gov (United States)

    Villamón, Eva; Piqueras, Marta; Meseguer, Javier; Blanquer, Ignacio; Berbegall, Ana P; Tadeo, Irene; Hernández, Vicente; Navarro, Samuel; Noguera, Rosa

    2013-03-01

    Translational research in oncology is directed mainly towards establishing a better risk stratification and searching for appropriate therapeutic targets. This research generates a tremendous amount of complex clinical and biological data needing speedy and effective management. The authors describe the design, implementation and early experiences of a computer-aided system for the integration and management of data for neuroblastoma patients. NeuPAT facilitates clinical and translational research, minimizes the workload in consolidating the information, reduces errors and increases correlation of data through extensive coding. This design can also be applied to other tumor types. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. The Killer Will Remain Free: On Pat Parker and the Poetics of Madness.

    Science.gov (United States)

    Ali, Kazim

    2015-01-01

    Poet and scholar Kazim Ali reads Pat Parker's Movement in Black intimately, one poet to another, uncovering the shadow-fact of the lives of most people of color: not only the anger that is somehow sublimated into every part of our lives but also the issue that carrying this feeling around has on our mental health itself-that "anger" and "madness" might have sources in one another. Ali concludes that Parker offers a brutal and clear-eyed and ultimately hopeful assessment of the conditions that were faced at the time, and even now, by communities of color.

  17. Process synthesis for natural products from plants based on PAT methodology

    DEFF Research Database (Denmark)

    Malwade, Chandrakant Ramkrishna; Qu, Haiyan; Rong, Ben-Guang

    2017-01-01

    (QbD) approach, has been included at various steps to obtain molecular level information of process streams and thereby, support the rational decision making. The formulated methodology has been used to isolate and purify artemisinin, an antimalarial drug, from dried leaves of the plant Artemisia...... generates different process flowsheet alternatives consisting of multiple separation techniques. Decision making is supported by heuristics as well as basic process information already available from previous studies. In addition, process analytical technology (PAT) framework, a part of Quality by Design...

  18. Wave propagation in electromagnetic media

    International Nuclear Information System (INIS)

    Davis, J.L.

    1990-01-01

    This book is concerned with wave propagation in reacting media, specifically in electromagnetic materials. An account is presented of the mathematical methods of wave phenomena in electromagnetic materials. The author presents the theory of time-varying electromagnetic fields, which involves a discussion of Faraday's laws, Maxwell's equations and their application to electromagnetic wave propagation under a variety of conditions. The author gives a discussion of magnetohydrodynamics and plasma physics. Chapters are included on quantum mechanics and the theory of relativity. The mathematical foundation of electromagnetic waves vis a vis partial differential equations is discussed

  19. Propagation testing multi-cell batteries.

    Energy Technology Data Exchange (ETDEWEB)

    Orendorff, Christopher J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lamb, Joshua [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Steele, Leigh Anna Marie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Spangler, Scott Wilmer [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-10-01

    Propagation of single point or single cell failures in multi-cell batteries is a significant concern as batteries increase in scale for a variety of civilian and military applications. This report describes the procedure for testing failure propagation along with some representative test results to highlight the potential outcomes for different battery types and designs.

  20. Vegetative Propagation and the Genetic Improvement of North American Hardwoods

    Science.gov (United States)

    R. E. Farmer

    1973-01-01

    Progress and problems in vegetative propagation of important North American hardwoods are reviewed with emphasis on rooting cuttings and the application of propagation techniques in breeding research. Some problems in rooting physiology are discussed.

  1. Combining two open source tools for neural computation (BioPatRec and Netlab) improves movement classification for prosthetic control.

    Science.gov (United States)

    Prahm, Cosima; Eckstein, Korbinian; Ortiz-Catalan, Max; Dorffner, Georg; Kaniusas, Eugenijus; Aszmann, Oskar C

    2016-08-31

    Controlling a myoelectric prosthesis for upper limbs is increasingly challenging for the user as more electrodes and joints become available. Motion classification based on pattern recognition with a multi-electrode array allows multiple joints to be controlled simultaneously. Previous pattern recognition studies are difficult to compare, because individual research groups use their own data sets. To resolve this shortcoming and to facilitate comparisons, open access data sets were analysed using components of BioPatRec and Netlab pattern recognition models. Performances of the artificial neural networks, linear models, and training program components were compared. Evaluation took place within the BioPatRec environment, a Matlab-based open source platform that provides feature extraction, processing and motion classification algorithms for prosthetic control. The algorithms were applied to myoelectric signals for individual and simultaneous classification of movements, with the aim of finding the best performing algorithm and network model. Evaluation criteria included classification accuracy and training time. Results in both the linear and the artificial neural network models demonstrated that Netlab's implementation using scaled conjugate training algorithm reached significantly higher accuracies than BioPatRec. It is concluded that the best movement classification performance would be achieved through integrating Netlab training algorithms in the BioPatRec environment so that future prosthesis training can be shortened and control made more reliable. Netlab was therefore included into the newest release of BioPatRec (v4.0).

  2. Modeling for the SAFRR Tsunami Scenario-generation, propagation, inundation, and currents in ports and harbors: Chapter D in The SAFRR (Science Application for Risk Reduction) Tsunami Scenario

    Science.gov (United States)

    ,

    2013-01-01

    This U.S. Geological Survey (USGS) Open-File report presents a compilation of tsunami modeling studies for the Science Application for Risk Reduction (SAFRR) tsunami scenario. These modeling studies are based on an earthquake source specified by the SAFRR tsunami source working group (Kirby and others, 2013). The modeling studies in this report are organized into three groups. The first group relates to tsunami generation. The effects that source discretization and horizontal displacement have on tsunami initial conditions are examined in section 1 (Whitmore and others). In section 2 (Ryan and others), dynamic earthquake rupture models are explored in modeling tsunami generation. These models calculate slip distribution and vertical displacement of the seafloor as a result of realistic fault friction, physical properties of rocks surrounding the fault, and dynamic stresses resolved on the fault. The second group of papers relates to tsunami propagation and inundation modeling. Section 3 (Thio) presents a modeling study for the entire California coast that includes runup and inundation modeling where there is significant exposure and estimates of maximum velocity and momentum flux at the shoreline. In section 4 (Borrero and others), modeling of tsunami propagation and high-resolution inundation of critical locations in southern California is performed using the National Oceanic and Atmospheric Administration’s (NOAA) Method of Splitting Tsunami (MOST) model and NOAA’s Community Model Interface for Tsunamis (ComMIT) modeling tool. Adjustments to the inundation line owing to fine-scale structures such as levees are described in section 5 (Wilson). The third group of papers relates to modeling of hydrodynamics in ports and harbors. Section 6 (Nicolsky and Suleimani) presents results of the model used at the Alaska Earthquake Information Center for the Ports of Los Angeles and Long Beach, as well as synthetic time series of the modeled tsunami for other selected

  3. Propagation of Satelite Rainfall Products uncertainties in hydrological applications : Examples in West-Africa in the framework of the Megha-Tropiques Satellite Mission

    Science.gov (United States)

    Casse, C.; Gosset, M.; Peugeot, C.; Boone, A.; Pedinotti, V.

    2013-12-01

    The use of satellite based rainfall in research or operational Hydrological application is becoming more and more frequent. This is specially true in the Tropics where ground based gauge (or radar) network are generally scarce and often degrading. Member of the GPM constellation, the new French-Indian satellite Mission Megha-Tropiques (MT) dedicated to the water and energy budget in the tropical atmosphere contributes to a better monitoring of rainfall in the inter-tropical zone. As part of this mission, research is developed on the use of MT rainfall products for hydrological research or operational application such as flood monitoring. A key issue for such applications is how to account for rainfall products biases and uncertainties, and how to propagate them in the end user models ? Another important question is how to choose the best space-time resolution for the rainfall forcing, given that both model performances and rain-product uncertainties are resolution dependent. This talk will present on going investigations and perspectives on this subject, with examples from the Megha_tropiques Ground validation sites in West Africa. The CNRM model Surfex-ISBA/TRIP has been set up to simulate the hydrological behavior of the Niger River. This modeling set up is being used to study the predictability of Niger Floods events in the city of Niamey and the performances of satellite rainfall products as forcing for such predictions. One of the interesting feature of the Niger outflow in Niamey is its double peak : a first peak attributed to 'local' rainfall falling in small to medium size basins situated in the region of Niamey, and a second peak linked to the rainfall falling in the upper par of the river, and slowly propagating through the river towards Niamey. The performances of rainfall products are found to differ between the wetter/upper part of the basin, and the local/sahelian areas. Both academic tests with artificially biased or 'perturbed' rainfield and actual

  4. Propagation of SLF/ELF electromagnetic waves

    CERN Document Server

    Pan, Weiyan

    2014-01-01

    This book deals with the SLF/ELF wave propagation, an important branch of electromagnetic theory. The SLF/ELF wave propagation theory is well applied in earthquake electromagnetic radiation, submarine communication, thunderstorm detection, and geophysical prospecting and diagnostics. The propagation of SLF/ELF electromagnetic waves is introduced in various media like the earth-ionospheric waveguide, ionospheric plasma, sea water, earth, and the boundary between two different media or the stratified media. Applications in the earthquake electromagnetic radiation and the submarine communications are also addressed. This book is intended for scientists and engineers in the fields of radio propagation and EM theory and applications. Prof. Pan is a professor at China Research Institute of Radiowave Propagation in Qingdao (China). Dr. Li is a professor at Zhejiang University in Hangzhou (China).

  5. Real-time determination of critical quality attributes using near-infrared spectroscopy: a contribution for Process Analytical Technology (PAT).

    Science.gov (United States)

    Rosas, Juan G; Blanco, Marcel; González, Josep M; Alcalà, Manel

    2012-08-15

    Process Analytical Technology (PAT) is playing a central role in current regulations on pharmaceutical production processes. Proper understanding of all operations and variables connecting the raw materials to end products is one of the keys to ensuring quality of the products and continuous improvement in their production. Near infrared spectroscopy (NIRS) has been successfully used to develop faster and non-invasive quantitative methods for real-time predicting critical quality attributes (CQA) of pharmaceutical granulates (API content, pH, moisture, flowability, angle of repose and particle size). NIR spectra have been acquired from the bin blender after granulation process in a non-classified area without the need of sample withdrawal. The methodology used for data acquisition, calibration modelling and method application in this context is relatively inexpensive and can be easily implemented by most pharmaceutical laboratories. For this purpose, Partial Least-Squares (PLS) algorithm was used to calculate multivariate calibration models, that provided acceptable Root Mean Square Error of Predictions (RMSEP) values (RMSEP(API)=1.0 mg/g; RMSEP(pH)=0.1; RMSEP(Moisture)=0.1%; RMSEP(Flowability)=0.6 g/s; RMSEP(Angle of repose)=1.7° and RMSEP(Particle size)=2.5%) that allowed the application for routine analyses of production batches. The proposed method affords quality assessment of end products and the determination of important parameters with a view to understanding production processes used by the pharmaceutical industry. As shown here, the NIRS technique is a highly suitable tool for Process Analytical Technologies. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Constrained bidirectional propagation and stroke segmentation

    Energy Technology Data Exchange (ETDEWEB)

    Mori, S; Gillespie, W; Suen, C Y

    1983-03-01

    A new method for decomposing a complex figure into its constituent strokes is described. This method, based on constrained bidirectional propagation, is suitable for parallel processing. Examples of its application to the segmentation of Chinese characters are presented. 9 references.

  7. Green synthesis and antimicrobial activity of silver nanoparticles using wild medicinal mushroom Ganoderma applanatum (Pers.) Pat. from Similipal Biosphere Reserve, Odisha, India.

    Science.gov (United States)

    Mohanta, Yugal Kishore; Singdevsachan, Sameer Kumar; Parida, Umesh Kumar; Panda, Sujogya Kumar; Mohanta, Tapan Kumar; Bae, Hanhong

    2016-08-01

    In the present study, green synthesis and cost effective approach of silver nanoparticles using wild medicinal mushroom Ganoderma applanatum (Pers.) Pat. from Similipal Biosphere Reserve, Odisha, India is reported. The biosynthesised AgNPs were characterised using UV-visible spectroscopy, particle analyser and scanning electron microscopy studies. It was found by dynamic light scattering analysis, that the average size and charges of the AgNPs were 133.0 ± 0.361 nm and -6.01 ± 5.30 mV, respectively. Moreover, the Fourier transform infrared study was also conducted to identify the biomolecules or functional groups responsible for the reduction of Ag and stabilisation of the AgNPs. The potential biomedical application with reference to antimicrobial activity of the synthesised AgNPs was investigated against some pathogenic microorganisms viz. Escherichia coli, Bacillus subtilis, Staphylococcus epidermidis, Vibrio cholerae, Staphylococcus aureus and Shigella flexneri.

  8. ACTS Propagation Measurements in Maryland and Virginia

    Science.gov (United States)

    Dissanayake, Asoka; Lin, Kuan-Ting

    1996-01-01

    Rapid growth in new satellite services incorporating very small aperture terminals (VSAT) and ultra small aperture terminals (USAT) is expected in the coming years. Small size terminals allow for widespread use of satellite services in small business and domestic applications. Due to congestion of lower frequency bands such as C and Ku, most of these services will use Ka-band (2/20 GHz) frequencies. Propagation impairments produced by the troposphere is a limiting factor for the effective use of the 20/30 GHz band and the use of smaller Earth terminals makes it difficult to provide sufficient link margins for propagation related outages. In this context, reliable prediction of propagation impairments for low margin systems becomes important. Due to the complexity of propagation phenomena propagation modeling is mainly attempted on an empirical basis. As such, the availability of reliable measured data that extend to probability levels well in excess of the traditional limit of 1 percent is of great importance in the development, validation, and refinement of propagation models. The beacon payload on the Advanced Communications Technology Satellite (ACTS) together with the propagation measurement terminals developed under the NASA ACTS propagation program provide an excellent opportunity to collect such data on a long-term basis. This paper presents the results of ACTS propagation measurements conducted in the Washington, DC metropolitan area by COMSAT Laboratories.

  9. Staphylococcus aureus, evolución de un viejo patógeno

    Directory of Open Access Journals (Sweden)

    Ileana Álvarez Lam

    2012-12-01

    Full Text Available El Staphylococcus aureus está considerado uno de los microorganismos más importantes en la práctica médica diaria. Es capaz de provocar una amplia gama de enfermedades, ya sea por acción directa o mediante la acción de sus toxinas. El tratamiento de estas infecciones se ha convertido en algo extraordinariamente complejo en la época actual como consecuencia de la aparición en la comunidad de cepas de S. aureus, resistentes a la meticillina, que provocan infecciones en pacientes sin factores de riesgo, fundamentalmente niños y adolescentes. En este artículo se hace una revisión, que va desde los cambios en la epidemiología de este patógeno, hasta las implicaciones que para el tratamiento médico presupone este fenómeno.

  10. Proceedings of the Twentieth NASA Propagation Experimenters Meeting (NAPEX XX) and the Advanced Communications Technology Satellite (ACTS) Propagation Studies Miniworkshop

    Science.gov (United States)

    Golshan, Nassar (Editor)

    1996-01-01

    The NASA Propagation Experimenters (NAPEX) Meeting and associated Advanced Communications Technology Satellite (ACTS) Propagation Studies Miniworkshop convene yearly to discuss studies supported by the NASA Propagation Program. Representatives from the satellite communications (satcom)industry, academia, and government with an interest in space-ground radio wave propagation have peer discussion of work in progress, disseminate propagation results, and interact with the satcom industry. NAPEX XX, in Fairbanks, Alaska, June 4-5, 1996, had three sessions: (1) "ACTS Propagation Study: Background, Objectives, and Outcomes," covered results from thirteen station-years of Ka-band experiments; (2) "Propagation Studies for Mobile and Personal Satellite Applications," provided the latest developments in measurement, modeling, and dissemination of propagation phenomena of interest to the mobile, personal, and aeronautical satcom industry; and (3)"Propagation Research Topics," covered a range of topics including space/ground optical propagation experiments, propagation databases, the NASA Propagation Web Site, and revision plans for the NASA propagation effects handbooks. The ACTS Miniworkshop, June 6, 1996, covered ACTS status, engineering support for ACTS propagation terminals, and the ACTS Propagation Data Center. A plenary session made specific recommendations for the future direction of the program.

  11. Intestinal drug transport via the proton-coupled amino acid transporter PAT1 (SLC36A1) is inhibited by Gly-X(aa) dipeptides

    DEFF Research Database (Denmark)

    Frølund, Sidsel; Langthaler, Louise; Kall, Morten A

    2012-01-01

    -Sar as substrates of the amino acid transporter PAT1. The aim of the present study is to investigate if other Gly-containing dipeptides interact with PAT1, and whether they can inhibit PAT1 mediated drug absorption, in vitro and in vivo. The in vitro methods included two-electrode voltage clamp measurements on h...... of different dipeptides. The in vivo part consisted of a pharmacokinetic study in rats following oral administration of gaboxadol and preadministration of 200 mg/kg dipeptide. The results showed that in hPAT1 expressing oocytes Gly-Tyr, Gly-Pro, and Gly-Phe inhibited currents induced by drug substances......, the present study identifies selected dipeptides as inhibitors of PAT1 mediated drug absorption in various in vitro models....

  12. The study of electromagnetic wave propagation in photonic crystals via planewave based transfer (scattering) matrix method with active gain material applications

    Science.gov (United States)

    Li, Ming

    material expressed by electric field dependent dielectric constant. Next, the concepts of spectrum interpolation (Chapter 3), higher-order incident (Chapter 4) and perfectly matched layer (Chapter 5) are introduced and applied to TMM, with detailed simulation for 1D, 2D, and 3D photonic crystal examples. Curvilinear coordinate transform is applied to the Maxwell's Equations to study waveguide bend (Chapter 6). By finding the phase difference along propagation direction at various XY plane locations, the behaviors of electromagnetic wave propagation (such as light bending, focusing etc) can be studied (Chapter 7), which can be applied to diffractive optics for new devices design. Numerical simulation tools for lasing devices are usually based on rate equations which are not accurate above the threshold and for small scale lasing cavities (such as nano-scale cavities). Recently, we extend the TMM package function to include the capacity of dealing active gain materials. Both lasing (above threshold) and spontaneous emission (below threshold) can be studied in the frame work of our Gain-TMM algorithm. Chapter 8 will illustrate the algorithm in detail and show the simulation results for 3D photonic crystal lasing devices. Then, microwave experiments (mainly resonant cavity embedded at layer-by-layer woodpile structures) are performed at Chapter 9 as an efficient practical way to study photonic crystal devices. The size of photonic crystal under microwave region is at the order of centimeter which makes the fabrication easier to realize. At the same time due to the scaling property, the result of microwave experiments can be applied directly to optical or infrared frequency regions. The systematic TMM simulations for various resonant cavities are performed and consistent results are obtained when compared with microwave experiments. Besides scaling the experimental results to much smaller wavelength, designing potential photonic crystal devices for application at microwave is

  13. Evaluación de patógenos en clones de lulo (Solanum quitoense Lam.

    Directory of Open Access Journals (Sweden)

    Consuelo Montes Rojas

    2010-04-01

    Full Text Available En el noroccidente de Popayán, Colombia, se evaluó la presencia de plagas causadas por patógenos en 42 clones de lulo (Solanum quitoense Lam.. Los clones fueron plantados en bolsas plásticas, donde se desarrollaron por 3 semanas antes de ser trasplantados al campo. Se utilizó un diseño de bloques completos al azar con cuatro repeticiones, la parcela útil estuvo conformada por 6 plantas, las cuales se sembraron a ‘tresbolillo’ a 2.5 m entre surcos y 2 m entre plantas. Para determinar el efecto de las plagas en el cultivo, se calculó el porcentaje de incidencia y severidad del ataque. La incidencia se evaluó como porcentaje de plantas afectadas, y la severidad como porcentaje de tejido afectado por el patógeno. Las enfermedades más limitantes para los 42 clones fueron: gota (Phytophthora infestans que provocó una mortalidad de plantas superior a 40%; fusarium (Fusarium oxysporum que se presentó en 12 de los clones evaluados; antracnosis (Colletotrichum sp. que afectó 21 clones, los cuales se clasificaron entre tolerantes y medianamente tolerantes; y mancha clorótica (Cladosporium sp. que afectó 21 clones, clasificados como susceptibles. Los clones PL19, PL24, PL11, PL35 fueron medianamente tolerantes. Se seleccionaron por supervivencia los clones: JY E1 (52.2%, PH E 1 (45.8%, VM E2 (45.8%; por supervivencia y por tolerancia a Fusarium oxysporum los clones PL35, PL11, PL24, PL8, PL19, 120052, 120043, ORE1, AGE1. Los clones SER 7, SER 15, SER 9, SEC 31, SEC 27 presentaron alta mortalidad pero se seleccionaron por ser medianamente tolerantes a gota, tolerantes a antracnosis y medianamente resistentes a nematodos, con buen vigor y producción.

  14. The Importance of Role Modeling in Mentoring Women: Lessons from Pat Summitt Legacy

    Directory of Open Access Journals (Sweden)

    Picariello Manuela

    2016-10-01

    Full Text Available The role of mentoring for women in sports industry has gathered attention among researchers in the past years (Bower, 2009; Bower, & Hums 2009, 2014; Weaver, & Chelladurai, 1999, 2002. Since few women are in leadership positions (Acosta, & Carpenter, 2014, cross-gender mentoring relationships are more likely to happen (Hopkins et al., 2008. However, according to Kram (1985, cross-gender mentoring relationships are more complex in terms of individual development and quality of the developmental relationship. In particular, role modeling function is limited (Kram, 1985. Therefore, the purpose of this study was to examine the functions of the same gender mentoring relationships looking at coach Pat Summitt, the winningest coach in NCAA Division I basketball history and a woman in leadership position (Becker & Wrisberg, 2008. Due to the exploratory nature of the study and the huge impact of Pat Summitt on sport (Janssen, & Dale, 2002, De Marco, & Mccullick, 1997, a single case study design to analyze her relationships from the staff and players’ perspectives was utilized as the method for data collection. This study collected data published on American news sites located using Internet search engines Google News (http://www.google.com for 7 days. The dataset included content published through national and regional online news media, radio, television and entertainment websites and blogs. Texts were qualitatively reviewed with a content analysis and coded (Patton, 2002. This study identified career and psychosocial functions that were important in developing an effective mentoring relationships. In particular, the psychosocial functions of “role modeling” was identified as the most important for the relationship. In fact a female mentor as a role model can be perceived as a woman that has successfully overcome discriminatory barriers to career advancement.

  15. CFD Modelling of a Pump as Turbine (PAT with Rounded Leading Edge Impellers for Micro Hydro Systems

    Directory of Open Access Journals (Sweden)

    Ismail Mohd Azlan

    2017-01-01

    Full Text Available A Pump as Turbine (PAT is one of micro hydro system components that is used to substitute a commercially available turbine due to its wide availability and low acquisition cost. However, PAT have high hydraulic losses due to differences in pump-turbine operation and hydraulic design. The fluid flowing inside the PAT is subjected to hydraulic losses due to the longer flow passage and unmatched fluid flow within the wall boundaries. This paper presents the effect of rounding the impeller leading edges of the pump on turbine performance. A CFD model of a PAT was designed to simulate virtual performance for the analysis. The aim of this study is to observe the internal hydraulic performance resulting from the changes in the performance characteristics. Highest efficiency was recorded at 17.0 l/s, an increase of 0.18%. The simulation results reveal that there is an improvement in hydraulic performance at overflow operation. The velocity vector visualization shows that there is a reduction in wake and consequently less flow separation along impeller flow passages. However, adjusting the sensitive impeller inlet geometry will also alter the velocity inlet vector and consequently change the velocity triangles for the turbo machinery system.

  16. The contact-temperature ignition (CTI) criteria for propagating chemical reactions including the effect of moisture and application to Hanford waste

    International Nuclear Information System (INIS)

    Cash, R.J.

    1995-01-01

    To assure the continued absence of uncontrolled condensed-phase chemical reactions in connection with the Hanford waste materials, efforts have been underway including both theoretical and experimental investigations to clarify the requirements for such reactions. This document defines the differences and requirements for homogeneous runaway and propagating chemical reactions incuding a discussion of general contact-temperature ignition (CTI) condition for propagating reactions that include the effect of moisture. The CTI condition implies that the contact temperature or interface temperature between reacted and unreacted materials must exceed the ignition temperature and is compared to experimental data including both synthetic ferrocyanide and surrogate organic materials. In all cases, the occurrences of ignition accompanied by self-propagating reactions are consistent with the theoretical anticipations of the CTI condition

  17. Corrosion Effects on the Fatigue Crack Propagation of Giga-Grade Steel and its Heat Affected Zone in pH Buffer Solutions for Automotive Application

    Science.gov (United States)

    Lee, H. S.

    2018-03-01

    Corrosion fatigue crack propagation test was conducted of giga-grade steel and its heat affected zone in pH buffer solutions, and the results were compared with model predictions. Pure corrosion effect on fatigue crack propagation, particularly, in corrosive environment was evaluated by means of the modified Forman equation. As shown in results, the average corrosion rate determined from the ratio of pure corrosion induced crack length to entire crack length under a cycle load were 0.11 and 0.37 for base metal and heat affected zone, respectively, with load ratio of 0.5, frequency of 0.5 and pH 10.0 environment. These results demonstrate new interpretation methodology for corrosion fatigue crack propagation enabling the pure corrosion effects on the behavior to be determined.

  18. Headspace solid-phase microextraction (HS-SPME) combined with GC-MS as a process analytical technology (PAT) tool for monitoring the cultivation of C. tetani.

    Science.gov (United States)

    Ghader, Masoud; Shokoufi, Nader; Es-Haghi, Ali; Kargosha, Kazem

    2018-04-15

    Vaccine production is a biological process in which variation in time and output is inevitable. Thus, the application of Process Analytical Technologies (PAT) will be important in this regard. Headspace solid - phase microextraction (HS-SPME) coupled with GC-MS can be used as a PAT for process monitoring. This method is suitable to chemical profiling of volatile organic compounds (VOCs) emitted from microorganisms. Tetanus is a lethal disease caused by Clostridium tetani (C. tetani) bacterium and vaccination is an ultimate way to prevent this disease. In this paper, SPME fiber was used for the investigation of VOCs emerging from C. tetani during cultivation. Different types of VOCs such as sulfur-containing compounds were identified and some of them were selected as biomarkers for bioreactor monitoring during vaccine production. In the second step, the portable dynamic air sampling (PDAS) device was used as an interface for sampling VOCs by SPME fibers. The sampling procedure was optimized by face-centered central composite design (FC-CCD). The optimized sampling time and inlet gas flow rates were 10 min and 2 m L s -1 , respectively. PDAS was mounted in exhausted gas line of bioreactor and 42 samples of VOCs were prepared by SPME fibers in 7 days during incubation. Simultaneously, pH and optical density (OD) were evaluated to cultivation process which showed good correlations with the identified VOCs (>80%). This method could be used for VOCs sampling from off-gas of a bioreactor to monitoring of the cultivation process. Copyright © 2018. Published by Elsevier B.V.

  19. Modelling the gluon propagator

    Energy Technology Data Exchange (ETDEWEB)

    Leinweber, D.B.; Parrinello, C.; Skullerud, J.I.; Williams, A.G

    1999-03-01

    Scaling of the Landau gauge gluon propagator calculated at {beta} = 6.0 and at {beta} = 6.2 is demonstrated. A variety of functional forms for the gluon propagator calculated on a large (32{sup 3} x 64) lattice at {beta} = 6.0 are investigated.

  20. Sound propagation in cities

    NARCIS (Netherlands)

    Salomons, E.; Polinder, H.; Lohman, W.; Zhou, H.; Borst, H.

    2009-01-01

    A new engineering model for sound propagation in cities is presented. The model is based on numerical and experimental studies of sound propagation between street canyons. Multiple reflections in the source canyon and the receiver canyon are taken into account in an efficient way, while weak

  1. Network propagation in the cytoscape cyberinfrastructure.

    Science.gov (United States)

    Carlin, Daniel E; Demchak, Barry; Pratt, Dexter; Sage, Eric; Ideker, Trey

    2017-10-01

    Network propagation is an important and widely used algorithm in systems biology, with applications in protein function prediction, disease gene prioritization, and patient stratification. However, up to this point it has required significant expertise to run. Here we extend the popular network analysis program Cytoscape to perform network propagation as an integrated function. Such integration greatly increases the access to network propagation by putting it in the hands of biologists and linking it to the many other types of network analysis and visualization available through Cytoscape. We demonstrate the power and utility of the algorithm by identifying mutations conferring resistance to Vemurafenib.

  2. Network propagation in the cytoscape cyberinfrastructure.

    Directory of Open Access Journals (Sweden)

    Daniel E Carlin

    2017-10-01

    Full Text Available Network propagation is an important and widely used algorithm in systems biology, with applications in protein function prediction, disease gene prioritization, and patient stratification. However, up to this point it has required significant expertise to run. Here we extend the popular network analysis program Cytoscape to perform network propagation as an integrated function. Such integration greatly increases the access to network propagation by putting it in the hands of biologists and linking it to the many other types of network analysis and visualization available through Cytoscape. We demonstrate the power and utility of the algorithm by identifying mutations conferring resistance to Vemurafenib.

  3. Evaluación de patógenos en clones de lulo (Solanum quitoense Lam.

    Directory of Open Access Journals (Sweden)

    Montes Rojas Consuelo

    2010-06-01

    Full Text Available

    En el noroccidente de Popayán, Colombia, se evaluó la presencia de plagas causadas por patógenos en 42 clones de lulo (Solanum quitoense Lam.. Los clones fueron plantados en bolsas plásticas, donde se desarrollaron por 3 semanas antes de ser trasplantados al campo. Se utilizó un diseño de bloques completos al azar con cuatro repeticiones, la parcela útil estuvo conformada por 6 plantas, las cuales se sembraron a 'tresbolillo' a 2.5 m entre surcos y 2 m entre plantas. Para determinar el efecto de las plagas en el cultivo, se calculó el porcentaje de incidencia y severidad del ataque. La incidencia se evaluó como porcentaje de plantas afectadas, y la severidad como porcentaje de tejido afectado por el patógeno. Las enfermedades más limitantes para los 42 clones fueron: gota (Phytophthora infestans que provocó una mortalidad de plantas superior a 40%; fusarium (Fusarium oxysporum que se presentó en 12 de los clones evaluados; antracnosis (Colletotrichum sp. que afectó 21 clones, los cuales se clasificaron entre tolerantes y medianamente tolerantes; y mancha clorótica (Cladosporium sp. que afectó 21 clones, clasificados como susceptibles. Los clones PL19, PL24, PL11, PL35 fueron medianamente tolerantes. Se seleccionaron por supervivencia los clones: JY E1 (52.2%, PH E 1 (45.8%, VM E2 (45.8%; por supervivencia y por tolerancia a Fusarium oxysporum los clones PL35, PL11, PL24, PL8, PL19, 120052, 120043, ORE1, AGE1. Los clones SER 7, SER 15, SER 9, SEC 31, SEC 27 presentaron alta mortalidad pero se seleccionaron por ser medianamente tolerantes a gota, tolerantes a antracnosis y medianamente resistentes a nematodos, con buen vigor y producción.

  4. Numerical simulation methods for wave propagation through optical waveguides

    International Nuclear Information System (INIS)

    Sharma, A.

    1993-01-01

    The simulation of the field propagation through waveguides requires numerical solutions of the Helmholtz equation. For this purpose a method based on the principle of orthogonal collocation was recently developed. The method is also applicable to nonlinear pulse propagation through optical fibers. Some of the salient features of this method and its application to both linear and nonlinear wave propagation through optical waveguides are discussed in this report. 51 refs, 8 figs, 2 tabs

  5. Experimental study of hot electrons propagation and energy deposition in solid or laser-shock compressed targets: applications to fast igniter

    International Nuclear Information System (INIS)

    Pisani, F.

    2000-02-01

    In the fast igniter scheme, a recent approach proposed for the inertial confinement fusion, the idea is to dissociate the fuel ignition phase from its compression. The ignition phase would be then achieved by means of an external energy source: a fast electron beam generated by the interaction with an ultra-intense laser. The main goal of this work is to study the mechanisms of the hot electron energy transfer to the compressed fuel. We intent in particular to study the role of the electric and collisional effects involved in the hot electron propagation in a medium with properties similar to the compressed fuel. We carried out two experiments, one at the Vulcan laser facility (England) and the second one at the new LULI 100 TW laser (France). During the first experiment, we obtained the first results on the hot electron propagation in a dense and hot plasma. The innovating aspect of this work was in particular the use of the laser-shock technique to generate high pressures, allowing the strongly correlated and degenerated plasma to be created. The role of the electric and magnetic effects due to the space charge associated with the fast electron beam has been investigated in the second experiment. Here we studied the propagation in materials with different electrical characteristics: an insulator and a conductor. The analysis of the results showed that only by taking into account simultaneously the two propagation mechanisms (collisions and electric effects) a correct treatment of the energy deposition is possible. We also showed the importance of taking into account the induced modifications due to the electrons beam crossing the target, especially the induced heating. (author)

  6. Modelling of waves propagation on irregular surfaces using ray tracing and GTD approaches: Application to head waves simulation in TOFD inspections for NDT

    International Nuclear Information System (INIS)

    Ferrand, Adrien; Darmon, Michel; Chatillon, Sylvain; Deschamps, Marc

    2014-01-01

    The Time of Flight Diffraction (TOFD) technique is a classical ultrasonic method used in ultrasonic non-destructive evaluation, which allows a precise positioning and a quantitative size evaluation of cracks in the inspected material. Among the typical phenomena arising in the current TOFD inspection, the so-called 'head wave' is the first contribution reaching the receiver. The head wave propagation on a planar interface is well known and identified as a critical refraction taking place on the material surface. On irregular surfaces, it has been shown that the head wave results from the melting of surface and bulk waves mechanisms and that surface irregularities are responsible for numerous diffractions of the incident head wave. To simulate such behaviour, a model has been developed using a ray tracing technique based on time of flight minimization (generalized Fermat's principle). It enables the calculation of the ray path and the corresponding time of flight of all waves propagating in the material, including the head wave. To obtain a complete propagation model for these waves (both trajectory and amplitude), the integration of Geometrical Theory of Diffraction (GTD) models is currently performed by coupling them with the ray-based approach discussed above.

  7. Modelling of waves propagation on irregular surfaces using ray tracing and GTD approaches: Application to head waves simulation in TOFD inspections for NDT

    Science.gov (United States)

    Ferrand, Adrien; Darmon, Michel; Chatillon, Sylvain; Deschamps, Marc

    2014-04-01

    The Time of Flight Diffraction (TOFD) technique is a classical ultrasonic method used in ultrasonic non-destructive evaluation, which allows a precise positioning and a quantitative size evaluation of cracks in the inspected material. Among the typical phenomena arising in the current TOFD inspection, the so-called "head wave" is the first contribution reaching the receiver. The head wave propagation on a planar interface is well known and identified as a critical refraction taking place on the material surface. On irregular surfaces, it has been shown that the head wave results from the melting of surface and bulk waves mechanisms and that surface irregularities are responsible for numerous diffractions of the incident head wave. To simulate such behaviour, a model has been developed using a ray tracing technique based on time of flight minimization (generalized Fermat's principle). It enables the calculation of the ray path and the corresponding time of flight of all waves propagating in the material, including the head wave. To obtain a complete propagation model for these waves (both trajectory and amplitude), the integration of Geometrical Theory of Diffraction (GTD) models is currently performed by coupling them with the ray-based approach discussed above.

  8. Photon activated therapy (PAT) using monochromatic synchrotron X-rays and iron oxide nanoparticles in a mouse tumor model: feasibility study of PAT for the treatment of superficial malignancy.

    Science.gov (United States)

    Choi, Gi-Hwan; Seo, Seung-Jun; Kim, Ki-Hong; Kim, Hong-Tae; Park, Sung-Hwan; Lim, Jae-Hong; Kim, Jong-Ki

    2012-10-31

    X-rays are known to interact with metallic nanoparticles, producing photoelectric species as radiosensitizing effects, and have been exploited in vivo mainly with gold nanoparticles. The purpose of this study was to investigate the potential of sensitizing effect of iron oxide nanoparticles for photon activated therapy. X-rays photon activated therapy (PAT) was studied by treating CT26 tumor cells and CT26 tumor-bearing mice loaded with 13-nm diameter FeO NP, and irradiating them at 7.1 keV near the Fe K-edge using synchrotron x-rays radiation. Survival of cells was determined by MTT assay, and tumor regression assay was performed for in vivo model experiment. The results of PAT treated groups were compared with x-rays alone control groups. A more significant reduction in viability and damage was observed in the FeO NP-treated irradiated cells, compared to the radiation alone group (p X-rays. Since 7.1 keV X-rays is attenuated very sharply in the tissue, FeO NP-PAT may have promise as a potent treatment option for superficial malignancies in the skin, like chest wall recurrence of breast cancer.

  9. Database for propagation models

    Science.gov (United States)

    Kantak, Anil V.

    1991-07-01

    A propagation researcher or a systems engineer who intends to use the results of a propagation experiment is generally faced with various database tasks such as the selection of the computer software, the hardware, and the writing of the programs to pass the data through the models of interest. This task is repeated every time a new experiment is conducted or the same experiment is carried out at a different location generating different data. Thus the users of this data have to spend a considerable portion of their time learning how to implement the computer hardware and the software towards the desired end. This situation may be facilitated considerably if an easily accessible propagation database is created that has all the accepted (standardized) propagation phenomena models approved by the propagation research community. Also, the handling of data will become easier for the user. Such a database construction can only stimulate the growth of the propagation research it if is available to all the researchers, so that the results of the experiment conducted by one researcher can be examined independently by another, without different hardware and software being used. The database may be made flexible so that the researchers need not be confined only to the contents of the database. Another way in which the database may help the researchers is by the fact that they will not have to document the software and hardware tools used in their research since the propagation research community will know the database already. The following sections show a possible database construction, as well as properties of the database for the propagation research.

  10. Inline monitoring and a PAT strategy for pharmaceutical hot melt extrusion.

    Science.gov (United States)

    Wahl, Patrick R; Treffer, Daniel; Mohr, Stefan; Roblegg, Eva; Koscher, Gerold; Khinast, Johannes G

    2013-10-15

    Implementation of continuous manufacturing in the pharmaceutical industry requires tight process control. This study focuses on a PAT strategy for hot melt extrusion of vegetable calcium stearate (CaSt) as matrix carrier and paracetamol as active pharmaceutical ingredient (API). The extrusion was monitored using in-line near-infrared (NIR) spectroscopy. A NIR probe was located in the section between the extrusion screws and the die, using a novel design of the die channel. A chemometric model was developed based on premixes at defined concentrations and was implemented in SIPAT for real time API concentration monitoring. Subsequently, step experiments were performed for different API concentrations, screw speeds and screw designs. The predicted API concentration was in good agreement with the pre-set concentrations. The transition from one API plateau to another was a smooth curve due to the mixing behaviour of the extruder. The accuracy of the model was confirmed via offline HPLC analysis. The screw design was determined as the main influential factor on content uniformity (CU). Additionally the influence of multiple feeders had a significant impact on CU. The results demonstrate that in-line NIR measurements is a powerful tool for process development (e.g., mixing characterization), monitoring and further control strategies. Copyright © 2013. Published by Elsevier B.V.

  11. PAT Design Strategy for Energy Recovery in Water Distribution Networks by Electrical Regulation

    Directory of Open Access Journals (Sweden)

    Helena M. Ramos

    2013-01-01

    Full Text Available In the management of water distribution networks, large energy savings can be yielded by exploiting the head drop due to the network pressure control strategy, i.e., for leak reductions. Hydropower in small streams is already exploited, but technical solutions combining efficiency and economic convenience are still required. In water distribution networks, an additional design problem comes out from the necessity of ensuring a required head drop under variable operating conditions, i.e., head and discharge variations. Both a hydraulic regulation (HR—via a series-parallel hydraulic circuit- and an electrical regulation (ER—via inverter- are feasible solutions. A design procedure for the selection of a production device in a series-parallel hydraulic circuit has been recently proposed. The procedure, named VOS (Variable Operating Strategy, is based on the overall plant efficiency criteria and is applied to a water distribution network where a PAT (pump as a turbine is used in order to produce energy. In the present paper the VOS design procedure has been extended to the electrical regulation and a comparison between HR and ER efficiency and flexibility within a water distribution network is shown: HR was found more flexible than ER and more efficient. Finally a preliminary economic study has been carried out in order to show the viability of both systems, and a shorter payback period of the electromechanical equipment was found for HR mode.

  12. Investigating Trauma in Narrating World War I: A Psychoanalytical Reading of Pat Barker’s Regeneration

    Directory of Open Access Journals (Sweden)

    Bakhtiar Sadjadi

    2016-12-01

    Full Text Available The present paper seeks to critically read Pat Barker’s Regeneration in terms of Cathy Caruth’s psychoanalytic study of trauma. This analysis attempts to trace the concepts of latency, post-traumatic stress disorders, traumatic memory, and trauma in Barker’s novel in order to explore how trauma and history are interrelated in the narrative of past history and, particularly, in the history of World War I. The present paper also demonstrates how Barker’s novel Regeneration acts as the narrative of trauma that vocalizes the silenced history of shell-shocked soldiers of World War I to represent British society, the history that has been concealed due to social and individual factors. The study thus investigates the dissociative disorders which are experienced by traumatized survivors of World War I as the aftermath of traumatic experiences of wartime. In addition, it argues how time moves for the traumatized victim and how the notion of latency in terms of Caruth’s theory is traceable in Barker’s novel. In Regeneration, the traumatized survivors are haunted with traumatic memory of past history; furthermore, past history constantly disrupts their present and the victims are in continuous shift from present time to past time. Time thus loses its linearity in the narrative of traumatized survivors. Keywords: Latency, post-traumatic stress disorders, traumatic memory, trauma

  13. Network and user interface for PAT DOME virtual motion environment system

    Science.gov (United States)

    Worthington, J. W.; Duncan, K. M.; Crosier, W. G.

    1993-01-01

    The Device for Orientation and Motion Environments Preflight Adaptation Trainer (DOME PAT) provides astronauts a virtual microgravity sensory environment designed to help alleviate tye symptoms of space motion sickness (SMS). The system consists of four microcomputers networked to provide real time control, and an image generator (IG) driving a wide angle video display inside a dome structure. The spherical display demands distortion correction. The system is currently being modified with a new graphical user interface (GUI) and a new Silicon Graphics IG. This paper will concentrate on the new GUI and the networking scheme. The new GUI eliminates proprietary graphics hardware and software, and instead makes use of standard and low cost PC video (CGA) and off the shelf software (Microsoft's Quick C). Mouse selection for user input is supported. The new Silicon Graphics IG requires an Ethernet interface. The microcomputer known as the Real Time Controller (RTC), which has overall control of the system and is written in Ada, was modified to use the free public domain NCSA Telnet software for Ethernet communications with the Silicon Graphics IG. The RTC also maintains the original ARCNET communications through Novell Netware IPX with the rest of the system. The Telnet TCP/IP protocol was first used for real-time communication, but because of buffering problems the Telnet datagram (UDP) protocol needed to be implemented. Since the Telnet modules are written in C, the Adap pragma 'Interface' was used to interface with the network calls.

  14. Extratos vegetais no controle de patógenos em sementes de Pterogyne nitens Tul

    Directory of Open Access Journals (Sweden)

    José George Ferreira Medeiros

    Full Text Available A demanda por sementes florestais para reflorestamento e outras finalidades poderá se constituir em um meio de disseminação de patógenos, que podem comprometer a qualidade fisiológica das sementes. Assim, objetivou-se avaliar o efeito de extratos naturais de melão-de-são-caetano (Momordica charantia e alamanda (Allamanda blanchetti sobre a micoflora e a fisiologia de sementes de Pterogyne nitens. Os seguintes tratamentos fitossanitários foram avaliados: testemunha (sementes não tratadas; fungicida Captan® (240 g/100 kg, e extratos de melão-de-são-caetano e alamanda nas concentrações de 10, 100, 500 e 1000 ppm. No teste de germinação, avaliaram-se a porcentagem de germinação, a primeira contagem e o índice de velocidade de germinação (IVG. Os extratos vegetais de melão-de-são-caetano e alamanda reduziram a incidência de fungos e aumentaram o percentual de germinação das sementes de P. nitens.

  15. Strategic funding priorities in the pharmaceutical sciences allied to Quality by Design (QbD) and Process Analytical Technology (PAT)

    DEFF Research Database (Denmark)

    Aksu, Buket; De Beer, Thomas; Folestad, Staffan

    2012-01-01

    however have the potential to provide considerable challenges to the establishment of cost effective and robust supply chains. To guarantee product quality and surety of supply for essential medicines it is necessary that manufacturing science keeps pace with advances in pharmaceutical R......Substantial changes in Pharmaceutical R&D strategy are required to address existing issues of low productivity, imminent patent expirations and pressures on pricing. Moves towards personalized healthcare and increasing diversity in the nature of portfolios including the rise of biopharmaceuticals......&D. In this position paper, the EUFEPS QbD and PAT Sciences network make recommendations that European industry, academia and health agencies focus attention on delivering step changes in science and technology in a number of key themes. These subject areas, all underpinned by the sciences allied to QbD and PAT...

  16. Transport of amino acids and GABA analogues via the human proton-coupled amino acid transporter, hPAT1

    DEFF Research Database (Denmark)

    Larsen, Mie; Larsen, Birger Brodin; Frølund, Bente

    2008-01-01

    The objective of this study was to investigate transepithelial amino acid transport as a function of Caco-2 cell culture time. Furthermore, the objective was to investigate apical uptake characteristics of hPAT1-mediated transport under various experimental conditions. Apical amino acid uptake......, which has been shown to function as a carboxylic acid bioisostere for substrates of the GABA receptor and transport systems....

  17. Dike Propagation Near Drifts

    International Nuclear Information System (INIS)

    2002-01-01

    The purpose of this Analysis and Model Report (AMR) supporting the Site Recommendation/License Application (SR/LA) for the Yucca Mountain Project is the development of elementary analyses of the interactions of a hypothetical dike with a repository drift (i.e., tunnel) and with the drift contents at the potential Yucca Mountain repository. This effort is intended to support the analysis of disruptive events for Total System Performance Assessment (TSPA). This AMR supports the Process Model Report (PMR) on disruptive events (CRWMS M and O 2000a). This purpose is documented in the development plan (DP) ''Coordinate Modeling of Dike Propagation Near Drifts Consequences for TSPA-SR/LA'' (CRWMS M and O 2000b). Evaluation of that Development Plan and the work to be conducted to prepare Interim Change Notice (ICN) 1 of this report, which now includes the design option of ''Open'' drifts, indicated that no revision to that DP was needed. These analyses are intended to provide reasonable bounds for a number of expected effects: (1) Temperature changes to the waste package from exposure to magma; (2) The gas flow available to degrade waste containers during the intrusion; (3) Movement of the waste package as it is displaced by the gas, pyroclasts and magma from the intruding dike (the number of packages damaged); (4) Movement of the backfill (Backfill is treated here as a design option); (5) The nature of the mechanics of the dike/drift interaction. These analyses serve two objectives: to provide preliminary analyses needed to support evaluation of the consequences of an intrusive event and to provide a basis for addressing some of the concerns of the Nuclear Regulatory Commission (NRC) expressed in the Igneous Activity Issue Resolution Status Report

  18. Propagation Characteristics of International Space Station Wireless Local Area Network

    Science.gov (United States)

    Sham, Catherine C.; Hwn, Shian U.; Loh, Yin-Chung

    2005-01-01

    This paper describes the application of the Uniform Geometrical Theory of Diffraction (UTD) for Space Station Wireless Local Area Networks (WLANs) indoor propagation characteristics analysis. The verification results indicate good correlation between UTD computed and measured signal strength. It is observed that the propagation characteristics are quite different in the Space Station modules as compared with those in the typical indoor WLANs environment, such as an office building. The existing indoor propagation models are not readily applicable to the Space Station module environment. The Space Station modules can be regarded as oversized imperfect waveguides. Two distinct propagation regions separated by a breakpoint exist. The propagation exhibits the guided wave characteristics. The propagation loss in the Space Station, thus, is much smaller than that in the typical office building. The path loss model developed in this paper is applicable for Space Station WLAN RF coverage and link performance analysis.

  19. Eliminación de patógenos en biosólidos por estabilización alcalina

    Directory of Open Access Journals (Sweden)

    Silva Leal Jorge Antonio

    2009-09-01

    Full Text Available La Planta de Tratamiento de Aguas Residuales de Cañaveralejo –PTAR-C de Cali– Colombia, produce alrededor de 100 t/día de biosólidos que, aunque no tienen restricción por metales pesados, son clase B por el nivel de microorganismos patógenos y parásitos. En un diseño completamente al azar, conformado por seis tratamientos con su respectivo duplicado, se evaluó la estabilización alcalina con dosis del 9% peso a peso de cal viva e hidratada, aplicada a pilas de 0.5 t de biosólidos húmedos (66.5% y secos a temperatura ambiente (25 - 31°C durante 72 h (humedad 50.1%. Con la estabilización alcalina el pH aumentó a valores superiores a 12 unidades durante el tiempo suficiente para garantizar la reducción de patógenos y parásitos, alcanzando un material clase A; sin embargo, el biosólido seco facilitó la formación de grumos que dificultaron las labores de homogenización del sustrato con los alcalinizantes, factor indeseable para la eficiente reducción de patógenos.

  20. Mr. Pat McDonald, Director of "Key Business Technologies", Department of Trade and Industry, United Kingdom

    CERN Multimedia

    Maximilien Brice

    2002-01-01

    Photos 01,02: Mr Pat McDonald, Director of "Key Business Technologies", Department of Trade and Industry, UK (third from left, front) in front of the ATLAS End-Cap Toroid vacuum vessel in the ATLAS assembly hall with, from left to right, Fred Wickens, Chris Jones, Peter Fletcher, Ray Browne, Neil Geddes, Jim Fleming, Anne Trefethen, Jim Wilson, Edwin Towndrow, Sharon Bonfield, Guy Rickett, Ken Smith, Peter Jenni. Photo 03: Mr Pat McDonald, Director of "Key Business Technologies", Department of Trade and Industry, UK (fifth from left) visiting ATLAS assembly hall with, from left to right, Jim Wilson, Peter Jenni, Ken Smith, Edwin Towndrow, Ray Brown, Chris Jones, Neil Geddes, Sharon Bonfield, Anne Trefethen, Jim Fleming, Fred Wickens. Photo 04: Mr Pat McDonald, Director of "Key Business Technologies", Department of Trade and Industry, UK (fourth from right) in front of the ATLAS Barrel Toroid coil casing in the ATLAS assembly hall with, from left to right, Peter Jenni, Jim Wilson, Guy Rickett, Anne Trefethen, ...

  1. Eliminación de patógenos en biosólidos por estabilización alcalina

    Directory of Open Access Journals (Sweden)

    Patricia Torres Lozada

    2009-07-01

    Full Text Available La Planta de Tratamiento de Aguas Residuales de Cañaveralejo -PTAR-C de Cali- Colombia, produce alrededor de 100 t/día de biosólidos que, aunque no tienen restricción por metales pesados, son clase B por el nivel de microorganismos patógenos y parásitos. En un diseño completamente al azar, conformado por seis tratamientos con su respectivo duplicado, se evaluó la estabilización alcalina con dosis del 9% peso a peso de cal viva e hidratada, aplicada a pilas de 0.5 t de biosólidos húmedos (66.5% y secos a temperatura ambiente (25 - 31°C durante 72 h (humedad 50.1%. Con la estabilización alcalina el pH aumentó a valores superiores a 12 unidades durante el tiempo suficiente para garantizar la reducción de patógenos y parásitos, alcanzando un material clase A; sin embargo, el biosólido seco facilitó la formación de grumos que dificultaron las labores de homogenización del sustrato con los alcalinizantes, factor indeseable para la eficiente reducción de patógenos.

  2. Petroleum and Oil Fuel Lines (Apra Harbor through Antonio B. Won Pat Intl Airport to Tanguisson Power Plant), Guam, 2016, US EPA Region 9

    Data.gov (United States)

    U.S. Environmental Protection Agency — This is a line feature dataset showing the track of petroleum and oil fuel lines that transport hazardous fluids from Apra Harbor through the Antonio B. Won Pat...

  3. Amino acid derivatives are substrates or non-transported inhibitors of the amino acid transporter PAT2 (slc36a2).

    Science.gov (United States)

    Edwards, Noel; Anderson, Catriona M H; Gatfield, Kelly M; Jevons, Mark P; Ganapathy, Vadivel; Thwaites, David T

    2011-01-01

    The H(+)-coupled amino acid transporter PAT2 (SLC36A2) transports the amino acids proline, glycine, alanine and hydroxyproline. A physiological role played by PAT2 in amino acid reabsorption in the renal proximal tubule is demonstrated by mutations in SLC36A2 that lead to an iminoglycinuric phenotype (imino acid and glycine uria) in humans. A number of proline, GABA and tryptophan derivatives were examined to determine if they function either as transported substrates or non-transported inhibitors of PAT2. The compounds were investigated following heterologous expression of rat PAT2 in Xenopus laevis oocytes. PAT2 function was characterised by: radiotracer uptake and competition (cis-inhibition) studies; radiotracer efflux and trans-stimulation; and measurement of substrate-induced positive inward current by two-electrode voltage-clamp. In general, the proline derivatives appeared to be transported substrates and the relative ability to induce current flow was closely related to the inhibitory effects on PAT2-mediated l-[(3)H]proline uptake. In contrast, certain heterocyclic GABA derivatives (e.g. l-pipecolic acid) were translocated only slowly. Finally, the tryptophan derivatives inhibited PAT2 function but did not undergo transport. l-Proline uptake was inhibited by 5-hydroxy-l-tryptophan (IC(50) 1.6±0.4mM), α-methyl-d,l-tryptophan (3.5±1.5mM), l-tryptophan, 1-methyl-l-tryptophan and indole-3-propionic acid. Although neither 5-hydroxy-l-tryptophan nor α-methyl-d,l-tryptophan were able to elicit inward current in PAT2-expressing oocytes both reduced the current evoked by l-proline. 5-Hydroxy-l-tryptophan and α-methyl-d,l-tryptophan were unable to trans-stimulate l-proline efflux from PAT2-expressing oocytes, confirming that the two compounds act as non-transported blockers of PAT2. These two tryptophan derivatives should prove valuable experimental tools in future investigations of the physiological roles of PAT2. Copyright © 2010 Elsevier B.V. All rights

  4. Estudio geoeléctrico en el valle alto del Rio Patía

    Directory of Open Access Journals (Sweden)

    Pérez Cerón Rosalbina

    1995-10-01

    Full Text Available

    The resistivity survey carried out at the upper valley of the Patía River, provided good information to define the sedimentary sequence of the area. A general sequence from top to base is described as follows: recent deposits with resistivity values between 20 and 400 Ohrn-m, fine to medium grain, sandstones with resistivity values between 20 and 70 Ohrn-m, fine grain sandstones and silstones with resistivity values between 8 and 20 Ohrn-rn, and clayli basement, with resistivity less than 20 Ohm-m. There are two kinds of aquifers; free, related to sands and gravels from alluvial fans and terraces (resistivity values between 70 and 400 Ohrn-m and thickness between 25 and 75, semi-confined related to tertiary sandstones (resistivities values between 20 and 30 Ohm-m, thickness between 35 and 150 m. The water quality of the upper aquifers is good enough with small amounts of salt content. Saline water is found at the lower aquifer.

    The resistivity method was useful to locate geological discontinuities; some of them found with surface expression associated with lineaments and faults. Some of these geological features have been mapped in previous geological works on the area. In general the interpretation based on the resistivity results shows a block tectonics environment affecting cretaceous and tertiary rocks and probably the quaternary deposit.

    La prospección eléctrica en el valle alto del Rio Patía, permitió definir una secuencia típica constituida de techo a base por

  5. Wave Propagation in Bimodular Geomaterials

    Science.gov (United States)

    Kuznetsova, Maria; Pasternak, Elena; Dyskin, Arcady; Pelinovsky, Efim

    2016-04-01

    Observations and laboratory experiments show that fragmented or layered geomaterials have the mechanical response dependent on the sign of the load. The most adequate model accounting for this effect is the theory of bimodular (bilinear) elasticity - a hyperelastic model with different elastic moduli for tension and compression. For most of geo- and structural materials (cohesionless soils, rocks, concrete, etc.) the difference between elastic moduli is such that their modulus in compression is considerably higher than that in tension. This feature has a profound effect on oscillations [1]; however, its effect on wave propagation has not been comprehensively investigated. It is believed that incorporation of bilinear elastic constitutive equations within theory of wave dynamics will bring a deeper insight to the study of mechanical behaviour of many geomaterials. The aim of this paper is to construct a mathematical model and develop analytical methods and numerical algorithms for analysing wave propagation in bimodular materials. Geophysical and exploration applications and applications in structural engineering are envisaged. The FEM modelling of wave propagation in a 1D semi-infinite bimodular material has been performed with the use of Marlow potential [2]. In the case of the initial load expressed by a harmonic pulse loading strong dependence on the pulse sign is observed: when tension is applied before compression, the phenomenon of disappearance of negative (compressive) strains takes place. References 1. Dyskin, A., Pasternak, E., & Pelinovsky, E. (2012). Periodic motions and resonances of impact oscillators. Journal of Sound and Vibration, 331(12), 2856-2873. 2. Marlow, R. S. (2008). A Second-Invariant Extension of the Marlow Model: Representing Tension and Compression Data Exactly. In ABAQUS Users' Conference.

  6. Project Integration Architecture: A Practical Demonstration of Information Propagation

    Science.gov (United States)

    Jones, William Henry

    2005-01-01

    One of the goals of the Project Integration Architecture (PIA) effort is to provide the ability to propagate information between disparate applications. With this ability, applications may then be formed into an application graph constituting a super-application. Such a super-application would then provide all of the analysis appropriate to a given technical system. This paper reports on a small demonstration of this concept in which a Computer Aided Design (CAD) application was connected to an inlet analysis code and geometry information automatically propagated from one to the other. The majority of the work reported involved not the technology of information propagation, but rather the conversion of propagated information into a form usable by the receiving application.

  7. Application of Fourier-wavelet regularized deconvolution for improving image quality of free space propagation x-ray phase contrast imaging.

    Science.gov (United States)

    Zhou, Zhongxing; Gao, Feng; Zhao, Huijuan; Zhang, Lixin

    2012-11-21

    New x-ray phase contrast imaging techniques without using synchrotron radiation confront a common problem from the negative effects of finite source size and limited spatial resolution. These negative effects swamp the fine phase contrast fringes and make them almost undetectable. In order to alleviate this problem, deconvolution procedures should be applied to the blurred x-ray phase contrast images. In this study, three different deconvolution techniques, including Wiener filtering, Tikhonov regularization and Fourier-wavelet regularized deconvolution (ForWaRD), were applied to the simulated and experimental free space propagation x-ray phase contrast images of simple geometric phantoms. These algorithms were evaluated in terms of phase contrast improvement and signal-to-noise ratio. The results demonstrate that the ForWaRD algorithm is most appropriate for phase contrast image restoration among above-mentioned methods; it can effectively restore the lost information of phase contrast fringes while reduce the amplified noise during Fourier regularization.

  8. Pengkajian Penerapan Teknik Budidaya Rhizophora mucronata dengan Stek Hipokotil (Study on Propagation Technique Application of Rhizophora mucronata Using Hypocotyl Cutting System

    Directory of Open Access Journals (Sweden)

    Neni Mulyani

    2007-01-01

    Full Text Available Research on the vegetative propagation of Rhizophora mucronata using hypocotyl cutting sistem was carried out at Faculty of Forestry, Bogor Agricultural University. Histological analysis of adventitous shoot was done at Biotechnology and Tree Breeding Laboratory, SEAMEO-BIOTROP. Three types of hypocotyl cutting (complete hypocotyl, top part of cut-hypocotyl and bottom part of cut-hypocotyl were induced using 6-BAP hormones at 0 and 500 ppm. Adventitous shoot of bottom part of cut-hypocotyl appeared 140 days after planting. Shoot from complete hypocotyl and top part of cut-hypocotyl grew earlier than adventitous shoot from bottom part of cut-hypocotyl. Hystologycal analysis of adventitous shoot showed the existance of primary meristem, stipule and leaf primordia. The growth of complete hipocotyl was higher than both of top part of cut-hypocotyl and bottom part of cut-hypocotyl. There was no effect of hormone induction on the shoot growth of them.

  9. Application of Gaussian beam ray-equivalent model and back-propagation artificial neural network in laser diode fast axis collimator assembly.

    Science.gov (United States)

    Yu, Hao; Rossi, Giammarco; Braglia, Andrea; Perrone, Guido

    2016-08-10

    The paper presents the development of a tool based on a back-propagation artificial neural network to assist in the accurate positioning of the lenses used to collimate the beam from semiconductor laser diodes along the so-called fast axis. After training using a Gaussian beam ray-equivalent model, the network is capable of indicating the tilt, decenter, and defocus of such lenses from the measured field distribution, so the operator can determine the errors with respect to the actual lens position and optimize the diode assembly procedure. An experimental validation using a typical configuration exploited in multi-emitter diode module assembly and fast axis collimating lenses with different focal lengths and numerical apertures is reported.

  10. Propagation environments [Chapter 4

    Science.gov (United States)

    Douglass F. Jacobs; Thomas D. Landis; Tara Luna

    2009-01-01

    An understanding of all factors influencing plant growth in a nursery environment is needed for the successful growth and production of high-quality container plants. Propagation structures modify the atmospheric conditions of temperature, light, and relative humidity. Native plant nurseries are different from typical horticultural nurseries because plants must be...

  11. Uncertainty Propagation in OMFIT

    Science.gov (United States)

    Smith, Sterling; Meneghini, Orso; Sung, Choongki

    2017-10-01

    A rigorous comparison of power balance fluxes and turbulent model fluxes requires the propagation of uncertainties in the kinetic profiles and their derivatives. Making extensive use of the python uncertainties package, the OMFIT framework has been used to propagate covariant uncertainties to provide an uncertainty in the power balance calculation from the ONETWO code, as well as through the turbulent fluxes calculated by the TGLF code. The covariant uncertainties arise from fitting 1D (constant on flux surface) density and temperature profiles and associated random errors with parameterized functions such as a modified tanh. The power balance and model fluxes can then be compared with quantification of the uncertainties. No effort is made at propagating systematic errors. A case study will be shown for the effects of resonant magnetic perturbations on the kinetic profiles and fluxes at the top of the pedestal. A separate attempt at modeling the random errors with Monte Carlo sampling will be compared to the method of propagating the fitting function parameter covariant uncertainties. Work supported by US DOE under DE-FC02-04ER54698, DE-FG2-95ER-54309, DE-SC 0012656.

  12. The Weinberg propagators

    International Nuclear Information System (INIS)

    Dvoeglazov, V.V.

    1997-01-01

    An analog of the j = 1/2 Feynman-Dyson propagator is presented in the framework of the j = 1 Weinberg's theory. The basis for this construction is the concept of the Weinberg field as a system of four field functions differing by parity and by dual transformations. (orig.)

  13. UWB Propagation through Walls

    Czech Academy of Sciences Publication Activity Database

    Schejbal, V.; Bezoušek, P.; Čermák, D.; NĚMEC, Z.; Fišer, Ondřej; Hájek, M.

    2006-01-01

    Roč. 15, č. 1 (2006), s. 17-24 ISSN 1210-2512 R&D Projects: GA MPO(CZ) FT-TA2/030 Institutional research plan: CEZ:AV0Z30420517 Keywords : Ultra wide band * UWB antennas * UWB propagation * multipath effects Subject RIV: JB - Sensors, Measurment, Regulation

  14. Tropical Cyclone Propagation

    National Research Council Canada - National Science Library

    Gray, William

    1994-01-01

    This paper discusses the question of tropical cyclone propagation or why the average tropical cyclone moves 1-2 m/s faster and usually 10-20 deg to the left of its surrounding (or 5-7 deg radius) deep layer (850-300 mb) steering current...

  15. Quality by design (QbD), Process Analytical Technology (PAT), and design of experiment applied to the development of multifunctional sunscreens.

    Science.gov (United States)

    Peres, Daniela D'Almeida; Ariede, Maira Bueno; Candido, Thalita Marcilio; de Almeida, Tania Santos; Lourenço, Felipe Rebello; Consiglieri, Vladi Olga; Kaneko, Telma Mary; Velasco, Maria Valéria Robles; Baby, André Rolim

    2017-02-01

    Multifunctional formulations are of great importance to ensure better skin protection from harm caused by ultraviolet radiation (UV). Despite the advantages of Quality by Design and Process Analytical Technology approaches to the development and optimization of new products, we found in the literature only a few studies concerning their applications in cosmetic product industry. Thus, in this research work, we applied the QbD and PAT approaches to the development of multifunctional sunscreens containing bemotrizinol, ethylhexyl triazone, and ferulic acid. In addition, UV transmittance method was applied to assess qualitative and quantitative critical quality attributes of sunscreens using chemometrics analyses. Linear discriminant analysis allowed classifying unknown formulations, which is useful for investigation of counterfeit and adulteration. Simultaneous quantification of ethylhexyl triazone, bemotrizinol, and ferulic acid presented at the formulations was performed using PLS regression. This design allowed us to verify the compounds in isolation and in combination and to prove that the antioxidant action of ferulic acid as well as the sunscreen actions, since the presence of this component increased 90% of antioxidant activity in vitro.

  16. Raman spectroscopy as a PAT for pharmaceutical blending: Advantages and disadvantages.

    Science.gov (United States)

    Riolo, Daniela; Piazza, Alessandro; Cottini, Ciro; Serafini, Margherita; Lutero, Emilio; Cuoghi, Erika; Gasparini, Lorena; Botturi, Debora; Marino, Iari Gabriel; Aliatis, Irene; Bersani, Danilo; Lottici, Pier Paolo

    2018-02-05

    Raman spectroscopy has been positively evaluated as a tool for the in-line and real-time monitoring of powder blending processes and it has been proved to be effective in the determination of the endpoint of the mixing, showing its potential role as process analytical technology (PAT). The aim of this study is to show advantages and disadvantages of Raman spectroscopy with respect to the most traditional HPLC analysis. The spectroscopic results, obtained directly on raw powders, sampled from a two-axis blender in real case conditions, were compared with the chromatographic data obtained on the same samples. The formulation blend used for the experiment consists of active pharmaceutical ingredient (API, concentrations 6.0% and 0.5%), lactose and magnesium stearate (as excipients). The first step of the monitoring process was selecting the appropriate wavenumber region where the Raman signal of API is maximal and interference from the spectral features of excipients is minimal. Blend profiles were created by plotting the area ratios of the Raman peak of API (A API ) at 1598cm -1 and the Raman bands of excipients (A EXC ), in the spectral range between 1560 and 1630cm -1 , as a function of mixing time: the API content can be considered homogeneous when the time-dependent dispersion of the area ratio is minimized. In order to achieve a representative sampling with Raman spectroscopy, each sample was mapped in a motorized XY stage by a defocused laser beam of a micro-Raman apparatus. Good correlation between the two techniques has been found only for the composition at 6.0% (w/w). However, standard deviation analysis, applied to both HPLC and Raman data, showed that Raman results are more substantial than HPLC ones, since Raman spectroscopy enables generating data rich blend profiles. In addition, the relative standard deviation calculated from a single map (30 points) turned out to be representative of the degree of homogeneity for that blend time. Copyright © 2017

  17. Efectos del agua ozonizada sobre microorganismos patógenos y alterantes de frutas y hortalizas

    Directory of Open Access Journals (Sweden)

    Laura Frisón

    2013-01-01

    Full Text Available La demanda de productos mínimamente procesados es creciente. Su inocuidad es un tema que preocupa tanto a procesadores, como a agencias de regulación y a consumidores. Las industrias han tenido que buscar métodos más eficaces para evitar el deterioro por microorganismos y mejorar la vida útil. Se considera que una sanitización es segura si el sanitizante logra reducir 5 log (99,999 % eficiencia la concentración de bacterias y 4 log (99,99 % eficiencia la concentración de mohos. Se estudió el efecto del agua ozonizada sobre bacterias patógenas como Bacillus cereus, Pseudomonas sp., Escherichia coli, Sthaphylococcus aureus y Salmonella sp. y sobre hongos fitopatógenos, micotoxigénicos y alterantes de frutas y hortalizas como Aspergillus niger, Penicillium digitatum, Alternaria alternata y Cladosporium cladosporioides.Se realizaron ensayos in vitro mediante el Test de Suspensión a 2 concentraciones de ozono en agua y 4 tiempos de exposición. Se logró determinar el siguiente orden descendente de resistencia en bacterias: B. cereus, Pseudomonas sp., E. coli, S. aureus y Salmonella sp. Se logró determinar el siguiente orden descendente de resistencia en mohos: A. niger, P. digitatum, A. alternata y C. cladosporioides. Se realizaron ensayos sobre hojas de lechuga, que contenían inoculadas las bacterias en estudio, con agua ozonizada ([2 ppm], por 5 minutos y sobre naranjas enteras, que contenían inoculadas conidios de los mohos en estudio, con agua ozonizada ([3 ppm], por 15 minutos. En ninguno de los ensayos se logró reducir más de 3 log la concentración de microorganismos. Teniendo en cuenta que las altas concentraciones de microorganismos inoculados en los ensayos (10E6 - 10E7 células/mL para bacterias y 10E5 - 10E6 conidios/mL para mohos no se encuentran normalmente en estos alimentos frescos, se puede inferir que el ozono podría utilizarse como sanitizante.

  18. Efectos del agua ozonizada sobre microorganismos patógenos y alterantes de frutas y hortalizas

    Directory of Open Access Journals (Sweden)

    Laura Frisón

    2013-06-01

    Full Text Available La demanda de productos mínimamente procesados es creciente. Su inocuidad es un tema que preocupa tanto a procesadores, como a agencias de regulación y a consumidores. Las industrias han tenido que buscar métodos más eficaces para evitar el deterioro por microorganismos y mejorar la vida útil. Se considera que una sanitización es segura si el sanitizante logra reducir 5 log (99,999 % eficiencia la concentración de bacterias y 4 log (99,99 % eficiencia la concentración de mohos. Se estudió el efecto del agua ozonizada sobre bacterias patógenas como Bacillus cereus, Pseudomonas sp., Escherichia coli, Sthaphylococcus aureus y Salmonella sp. y sobre hongos fitopatógenos, micotoxigénicos y alterantes de frutas y hortalizas como Aspergillus niger, Penicillium digitatum, Alternaria alternata y Cladosporium cladosporioides. Se realizaron ensayos in vitro mediante el Test de Suspensión a 2 concentraciones de ozono en agua y 4 tiempos de exposición. Se logró determinar el siguiente orden descendente de resistencia en bacterias: B. cereus, Pseudomonas sp., E. coli, S. aureus y Salmonella sp. Se logró determinar el siguiente orden descendente de resistencia en mohos:A. niger, P. digitatum, A. alternata y C. cladosporioides. Se realizaron ensayos sobre hojas de lechuga, que contenían inoculadas las bacterias en estudio, con agua ozonizada ([2 ppm], por 5 minutos y sobre naranjas enteras, que contenían inoculadas conidios de los mohos en estudio, con agua ozonizada ([3 ppm], por 15 minutos. En ninguno de los ensayos se logró reducir más de 3 log la concentración de microorganismos. Teniendo en cuenta que las altas concentraciones de microorganismos inoculados en los ensayos (106 - 107 células/mL para bacterias y 105 - 106 conidios/mL para mohos no se encuentran normalmente en estos alimentos frescos, se puede inferir que el ozono podría utilizarse como sanitizante.

  19. Review of the High Performance Antiproton Trap (HiPAT) Experiment at the Marshall Space Flight Center

    Science.gov (United States)

    Pearson, J. B.; Sims, Herb; Martin, James; Chakrabarti, Suman; Lewis, Raymond; Fant, Wallace

    2003-01-01

    The significant energy density of matter-antimatter annihilation is attractive to the designers of future space propulsion systems, with the potential to offer a highly compact source of power. Many propulsion concepts exist that could take advantage of matter-antimatter reactions, and current antiproton production rates are sufficient to support basic proof-of-principle evaluation of technology associated with antimatter- derived propulsion. One enabling technology for such experiments is portable storage of low energy antiprotons, allowing antiprotons to be trapped, stored, and transported for use at an experimental facility. To address this need, the Marshall Space Flight Center's Propulsion Research Center is developing a storage system referred to as the High Performance Antiproton Trap (HiPAT) with a design goal of containing 10(exp 12) particles for up to 18 days. The HiPAT makes use of an electromagnetic system (Penning- Malmberg design) consisting of a 4 Telsa superconductor, high voltage electrode structure, radio frequency (RF) network, and ultra high vacuum system. To evaluate the system normal matter sources (both electron guns and ion sources) are used to generate charged particles. The electron beams ionize gas within the trapping region producing ions in situ, whereas the ion sources produce the particles external to the trapping region and required dynamic capture. A wide range of experiments has been performed examining factors such as ion storage lifetimes, effect of RF energy on storage lifetime, and ability to routinely perform dynamic ion capture. Current efforts have been focused on improving the FW rotating wall system to permit longer storage times and non-destructive diagnostics of stored ions. Typical particle detection is performed by extracting trapped ions from HiPAT and destructively colliding them with a micro-channel plate detector (providing number and energy information). This improved RF system has been used to detect various

  20. Photon Propagation through Linearly Active Dimers

    Directory of Open Access Journals (Sweden)

    José Delfino Huerta Morales

    2017-06-01

    Full Text Available We provide an analytic propagator for non-Hermitian dimers showing linear gain or losses in the quantum regime. In particular, we focus on experimentally feasible realizations of the PT -symmetric dimer and provide their mean photon number and second order two-point correlation. We study the propagation of vacuum, single photon spatially-separable, and two-photon spatially-entangled states. We show that each configuration produces a particular signature that might signal their possible uses as photon switches, semi-classical intensity-tunable sources, or spatially entangled sources to mention a few possible applications.

  1. Propagator of stochastic electrodynamics

    International Nuclear Information System (INIS)

    Cavalleri, G.

    1981-01-01

    The ''elementary propagator'' for the position of a free charged particle subject to the zero-point electromagnetic field with Lorentz-invariant spectral density proportionalω 3 is obtained. The nonstationary process for the position is solved by the stationary process for the acceleration. The dispersion of the position elementary propagator is compared with that of quantum electrodynamics. Finally, the evolution of the probability density is obtained starting from an initial distribution confined in a small volume and with a Gaussian distribution in the velocities. The resulting probability density for the position turns out to be equal, to within radiative corrections, to psipsi* where psi is the Kennard wave packet. If the radiative corrections are retained, the present result is new since the corresponding expression in quantum electrodynamics has not yet been found. Besides preceding quantum electrodynamics for this problem, no renormalization is required in stochastic electrodynamics

  2. Preventing Unofficial Information Propagation

    Science.gov (United States)

    Le, Zhengyi; Ouyang, Yi; Xu, Yurong; Ford, James; Makedon, Fillia

    Digital copies are susceptible to theft and vulnerable to leakage, copying, or manipulation. When someone (or some group), who has stolen, leaked, copied, or manipulated digital documents propagates the documents over the Internet and/or distributes those through physical distribution channels many challenges arise which document holders must overcome in order to mitigate the impact to their privacy or business. This paper focuses on the propagation problem of digital credentials, which may contain sensitive information about a credential holder. Existing work such as access control policies and the Platform for Privacy Preferences (P3P) assumes that qualified or certified credential viewers are honest and reliable. The proposed approach in this paper uses short-lived credentials based on reverse forward secure signatures to remove this assumption and mitigate the damage caused by a dishonest or honest but compromised viewer.

  3. Rapid localized deactivation of self-assembled monolayers by propagation-controlled laser-induced plasma and its application to self-patterning of electronics and biosensors

    Science.gov (United States)

    Kim, Jongsu; Kwon, Seung-Gab; Back, Seunghyun; Kang, Bongchul

    2018-03-01

    We present a novel laser-induced surface treatment process to rapidly control the spatial wettabilities of various functional solutions with submicron to micron resolutions. Ultrathin hydrophobic self-assembled monolayers (SAMs) that little absorb typical laser lights due to short penetration depth were selectively deactivated by instantaneous interaction with laser-induced metallic plasmas. The spatial region of the deactivated SAM, which corresponds to process resolution, is adjustable by controlling the spatial propagation of the plasma. This method leads to the parallel formation of hydrophilic functional solutions on glass substrates with a minimum resolution on the submicron scale. To show its feasibility in device engineering fields, this method was applied to the cost-effective fabrication of electronics and biosensors. Rapid self-patterning of electronic and biological functional solutions (silver nanoparticle solution and streptavidin protein solution) was successfully realized by selective deactivation of two different SAMs (tridecafluoro-1,1,2,2-tetrahydrooctyltrichlorosilane (FOTS) for electronics and the hetero-hybrid SAM (octadecyltrichlorosilane (OTS)/2-[methoxy(polyethyleneoxy)propyl] trichlorosilane (PEG)) for biosensors). As a result, this method can be exploited for the rapid and low-cost fabrication of various thin film devices such as electronics, biosensors, energy, displays, and photonics.

  4. Safety evaluation of the phosphinothricin acetyltransferase proteins encoded by the pat and bar sequences that confer tolerance to glufosinate-ammonium herbicide in transgenic plants.

    Science.gov (United States)

    Hérouet, Corinne; Esdaile, David J; Mallyon, Bryan A; Debruyne, Eric; Schulz, Arno; Currier, Thomas; Hendrickx, Koen; van der Klis, Robert-Jan; Rouan, Dominique

    2005-03-01

    Transgenic plant varieties, which are tolerant to glufosinate-ammonium, were developed. The herbicide tolerance is based upon the presence of either the bar or the pat gene, which encode for two homologous phosphinothricin acetyltransferases (PAT), in the plant genome. Based on both a review of published literature and experimental studies, the safety assessment reviews the first step of a two-step-approach for the evaluation of the safety of the proteins expressed in plants. It can be used to support the safety of food or feed products derived from any crop that contains and expresses these PAT proteins. The safety evaluation supports the conclusion that the genes and the donor microorganisms (Streptomyces) are innocuous. The PAT enzymes are highly specific and do not possess the characteristics associated with food toxins or allergens, i.e., they have no sequence homology with any known allergens or toxins, they have no N-glycosylation sites, they are rapidly degraded in gastric and intestinal fluids, and they are devoid of adverse effects in mice after intravenous administration at a high dose level. In conclusion, there is a reasonable certainty of no harm resulting from the inclusion of the PAT proteins in human food or in animal feed.

  5. New Application of Bioelectrical Impedance Analysis by the Back Propagation Artificial Neural Network Mathematically Predictive Model of Tissue Composition in the Lower Limbs of Elderly People

    Directory of Open Access Journals (Sweden)

    Tsang-Pai Liu

    2012-03-01

    Conclusion: In summary, the greater predictive accuracy and precision made the application of BIA with the BP–ANN mathematical model more feasible for the clinical measurement of FM and FFM in the lower limbs of elderly people.

  6. Experimental study of hot electrons propagation and energy deposition in solid or laser-shock compressed targets: applications to fast igniter; Etude experimentale de la propagation et du depot d'energie d'electrons rapides dans une cible solide ou comprimee par choc laser: application a l'allumeur rapide

    Energy Technology Data Exchange (ETDEWEB)

    Pisani, F

    2000-02-15

    In the fast igniter scheme, a recent approach proposed for the inertial confinement fusion, the idea is to dissociate the fuel ignition phase from its compression. The ignition phase would be then achieved by means of an external energy source: a fast electron beam generated by the interaction with an ultra-intense laser. The main goal of this work is to study the mechanisms of the hot electron energy transfer to the compressed fuel. We intent in particular to study the role of the electric and collisional effects involved in the hot electron propagation in a medium with properties similar to the compressed fuel. We carried out two experiments, one at the Vulcan laser facility (England) and the second one at the new LULI 100 TW laser (France). During the first experiment, we obtained the first results on the hot electron propagation in a dense and hot plasma. The innovating aspect of this work was in particular the use of the laser-shock technique to generate high pressures, allowing the strongly correlated and degenerated plasma to be created. The role of the electric and magnetic effects due to the space charge associated with the fast electron beam has been investigated in the second experiment. Here we studied the propagation in materials with different electrical characteristics: an insulator and a conductor. The analysis of the results showed that only by taking into account simultaneously the two propagation mechanisms (collisions and electric effects) a correct treatment of the energy deposition is possible. We also showed the importance of taking into account the induced modifications due to the electrons beam crossing the target, especially the induced heating. (author)

  7. A two-dimensional hybrid method for modeling seismic waves propagation in laterally-varying anisotropic media and its application to central Tibet

    Science.gov (United States)

    Zhao, L.; Wen, L.

    2009-12-01

    The shear wave splitting measurements provide important information on mantle flow, deformation and mineralogy. They are now routinely made using the method developed by Silver and Chan (1994). More and more dense regional observations also begin to reveal sharp spatial variations of seismic anisotropy which could not be explained by simplified horizontal homogeneous anisotropic structures. To better constrain the mantle anisotropy beneath those regions, we developed a two-dimensional hybrid method for simulating seismic wave propagation in laterally-varying anisotropic media [Zhao et al., 2008]. In this presentation, we apply the method to study anisotropic structures beneath central Tibet by waveform modeling the teleseismic SKS phases recorded in the International Deep Profiling of Tibet and the Himalayas project (INDEPTH) III. Using data from two events that were selected such that the stations and sources can be approximated as a two-dimensional profile, we derived an optimal model for the anisotropic structures of the upper mantle beneath the study region: a 50-70 km thick anisotropic layer with a fast direction trending N95°E beneath the Qiangtang block, a 150 km thick and 60 km wide anisotropic segment with an axis trending N95°E beneath the northernmost Lhasa block, and a ~30 km wide transition zone in between within which the fast direction trends N45°E and the depth extent of anisotropy decreases northward sharply. Synthetic waveform modeling further suggests that an anisotropic model with a horizontal symmetry axis can explain the observations better than that with a dipping symmetry, and a low velocity zone possibly underlies or mixes with the anisotropic structures in the northern portion of the region. The optimal model yields synthetic seismograms that are in good agreement with the observations in both amplitudes and relative arrival times of SKS phases. Synthetic tests also indicate that different elastic constants, source parameters and depth

  8. Contribution to the determination of the double angular and energy differential neutron albedo. Application to the propagation in lacunar medium; Contribution a la determination de l'albedo doublement differentiel en angle et en energie des neutrons. Application a la propagation dans les milieux lacunaires

    Energy Technology Data Exchange (ETDEWEB)

    Litaize, O

    2000-07-01

    The goal of this thesis is to study the neutron propagation by reflection from lacunar medium interfaces. The most efficient method to calculate this type of propagation is to use the concept of albedo. Actual version of NARCISSE code uses a simple formulation of angular differential albedos and so, can only treat single reflections. Multiple reflections treatment needs the knowledge of neutron spectrum after reflection. This energetic information is contained in double angular and energy differential albedos. The first step of this study consists to generate these albedos for various materials. Several methods have been tested and the Monte Carlo method was retained. A new estimator has been developed and validated in the Mote Carlo transport code TRIPOLI-4. It computes, during the simulation of the neutron history, the angular and energy reflection probability at each collision site. The second step consists to generate an interpolation scheme and albedo libraries for various materials. A new version of NARCISSE was developed to use these libraries and the interpolation module. Spectrum and dose rates comparisons were made between codes to validate these albedos. The neutron propagation by multiple reflections can be studied now, by using this new version of Narcisse. (author)

  9. Contribution to the determination of the double angular and energy differential neutron albedo. Application to the propagation in lacunar medium; Contribution a la determination de l'albedo doublement differentiel en angle et en energie des neutrons. Application a la propagation dans les milieux lacunaires

    Energy Technology Data Exchange (ETDEWEB)

    Litaize, O

    2000-07-01

    The goal of this thesis is to study the neutron propagation by reflection from lacunar medium interfaces. The most efficient method to calculate this type of propagation is to use the concept of albedo. Actual version of NARCISSE code uses a simple formulation of angular differential albedos and so, can only treat single reflections. Multiple reflections treatment needs the knowledge of neutron spectrum after reflection. This energetic information is contained in double angular and energy differential albedos. The first step of this study consists to generate these albedos for various materials. Several methods have been tested and the Monte Carlo method was retained. A new estimator has been developed and validated in the Mote Carlo transport code TRIPOLI-4. It computes, during the simulation of the neutron history, the angular and energy reflection probability at each collision site. The second step consists to generate an interpolation scheme and albedo libraries for various materials. A new version of NARCISSE was developed to use these libraries and the interpolation module. Spectrum and dose rates comparisons were made between codes to validate these albedos. The neutron propagation by multiple reflections can be studied now, by using this new version of Narcisse. (author)

  10. Thermal propagation and stability in superconducting films

    International Nuclear Information System (INIS)

    Gray, K.E.; Kampwirth, R.T.; Zasadzinski, J.F.; Ducharme, S.P.

    1983-01-01

    Thermal propagation and stable hot spots (normal domains) are studied in various high Tsub(c) superconducting films (Nb 3 Sn, Nb, NbN and Nb 3 Ge). A new energy balance is shown to give reasonable quantitative agreement of the dependence of the propagation velocity on the length of short normal domains. The steady state (zero velocity) measurements indicate the existence of two distinct situations for films on high thermal conductivity (sapphire) substrates. For low power per unit area the film and substrate have the same temperature, and the thermal properties of the substrate dominate. However, for higher power densities in short hot spots, the coupling is relatively weak and the thermal properties of the film alone are important. Here a connection is made between the critical current stability of superconducting films and a critical hot spot size for thermal propagation. As a result efficient heat removal is shown to dominate the stabilisation of superconducting films. The strong and weak coupling situations also lead to modifications of the models for propagation velocities on sapphire substrates. Self-healing of hot spots and other phenomena in superconducting film are explained. The potential use of the thermal propagation model in applications of superconductors, especially switches is discussed. (author)

  11. Nonlinear operators and their propagators

    International Nuclear Information System (INIS)

    Schwartz, C.

    1997-01-01

    Mathematical physicists are familiar with a large set of tools designed for dealing with linear operators, which are so common in both the classical and quantum theories; but many of those tools are useless with nonlinear equations of motion. In this work a general algebra and calculus is developed for working with nonlinear operators: The basic new tool being the open-quotes slash product,close quotes defined by A(1+εB) =A+εA/B+O(ε 2 ). For a generic time development equation, the propagator is constructed and then there follows the formal version of time dependent perturbation theory, in remarkable similarity to the linear situation. A nonperturbative approximation scheme capable of producing high accuracy computations, previously developed for linear operators, is shown to be applicable as well in the nonlinear domain. A number of auxiliary mathematical properties and examples are given. copyright 1997 American Institute of Physics

  12. Mass-spectrometry analysis of histone post-translational modifications in pathology tissue using the PAT-H-MS approach

    Directory of Open Access Journals (Sweden)

    Roberta Noberini

    2016-06-01

    Full Text Available Aberrant histone post-translational modifications (hPTMs have been implicated with various pathologies, including cancer, and may represent useful epigenetic biomarkers. The data described here provide a mass spectrometry-based quantitative analysis of hPTMs from formalin-fixed paraffin-embedded (FFPE tissues, from which histones were extracted through the recently developed PAT-H-MS method. First, we analyzed FFPE samples from mouse spleen and liver or human breast cancer up to six years old, together with their corresponding fresh frozen tissue. We then combined the PAT-H-MS approach with a histone-focused version of the super-SILAC strategy-using a mix of histones from four breast cancer cell lines as a spike-in standard- to accurately quantify hPTMs from breast cancer specimens belonging to different subtypes. The data, which are associated with a recent publication (Pathology tissue-quantitative mass spectrometry analysis to profile histone post-translational modification patterns in patient samples (Noberini, 2015 [1], are deposited at the ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifier http://www.ebi.ac.uk/pride/archive/projects/PXD002669.

  13. Human induced discharge diversion in a tropical delta and its environmental implications: The Patía River, Colombia

    Science.gov (United States)

    Restrepo, Juan D.; Kettner, Albert

    2012-03-01

    SummaryThe Patía River, the number one in terms of sediment yield ˜1500 t km-2 yr-1 draining the western South America, has the most extensive and well developed delta on the Pacific coast, measuring 1700 km2. During the Holocene, nature forced the Patía delta to the south; however, a major water diversion, starting in 1972, diverted the Patía flow to the Sanguianga River, the latter, a small stream draining internal lakes from the Pacific lowlands. This human induced discharge diversion shifted the active delta plain back to the north and changed the northern estuarine system into an active delta plain. Overall, major environmental consequences of this discharge diversion in terms of morphological changes along the delta coast and distributary channels, are evidenced by: (1) coastal retreat along the abandoned delta lobe; 63% of the southern shoreline is retreating at maximum rates of 7 m yr-1, with a corresponding coastal land loss of 106 m yr-1; (2) transgressive barrier islands with exposed peat soils in the surf zone; (3) abandonment of former active distributaries in the southern delta plain with associated closing of inlets and formation of ebb tidal deltas; (4) breaching events on barrier islands; and (5) distributary channel accretion in the northern delta plain by morphological processes such as sedimentation (also in crevasses), overbank flow, increasing width of levees, interdistributary channel fill, and colonization of pioneer mangrove. The Sanguianga Mangrove National Park (SMNP), the largest mangrove reserve in Colombia, measuring 800 km2, lies in this former estuary, where major hydrologic and sedimentation changes are occurring. Observed environmental changes in the SMNP, include (1) seaward advance of the sub-aqueous delta front at the Sanquianga inlet evidenced by an increase in tidal flat area from 5.4 Mm2 in 1986 to 14 Mm2 in 2001; (2) freshening conditions in the Sanguianga distributary channel, a hydrologic change that has shifted the

  14. Wave propagation in elastic solids

    CERN Document Server

    Achenbach, Jan

    1984-01-01

    The propagation of mechanical disturbances in solids is of interest in many branches of the physical scienses and engineering. This book aims to present an account of the theory of wave propagation in elastic solids. The material is arranged to present an exposition of the basic concepts of mechanical wave propagation within a one-dimensional setting and a discussion of formal aspects of elastodynamic theory in three dimensions, followed by chapters expounding on typical wave propagation phenomena, such as radiation, reflection, refraction, propagation in waveguides, and diffraction. The treat

  15. Temporal scaling in information propagation

    Science.gov (United States)

    Huang, Junming; Li, Chao; Wang, Wen-Qiang; Shen, Hua-Wei; Li, Guojie; Cheng, Xue-Qi

    2014-06-01

    For the study of information propagation, one fundamental problem is uncovering universal laws governing the dynamics of information propagation. This problem, from the microscopic perspective, is formulated as estimating the propagation probability that a piece of information propagates from one individual to another. Such a propagation probability generally depends on two major classes of factors: the intrinsic attractiveness of information and the interactions between individuals. Despite the fact that the temporal effect of attractiveness is widely studied, temporal laws underlying individual interactions remain unclear, causing inaccurate prediction of information propagation on evolving social networks. In this report, we empirically study the dynamics of information propagation, using the dataset from a population-scale social media website. We discover a temporal scaling in information propagation: the probability a message propagates between two individuals decays with the length of time latency since their latest interaction, obeying a power-law rule. Leveraging the scaling law, we further propose a temporal model to estimate future propagation probabilities between individuals, reducing the error rate of information propagation prediction from 6.7% to 2.6% and improving viral marketing with 9.7% incremental customers.

  16. Prediction of tides using back-propagation neural networks

    Digital Repository Service at National Institute of Oceanography (India)

    Mandal, S.

    Prediction of tides is very much essential for human activities and to reduce the construction cost in marine environment. This paper presents an application of the artificial neural network with back-propagation procedures for accurate prediction...

  17. Mark report satellite tags (mrPATs) to detail large-scale horizontal movements of deep water species: First results for the Greenland shark (Somniosus microcephalus)

    Science.gov (United States)

    Hussey, Nigel E.; Orr, Jack; Fisk, Aaron T.; Hedges, Kevin J.; Ferguson, Steven H.; Barkley, Amanda N.

    2018-04-01

    The deep-sea is increasingly viewed as a lucrative environment for the growth of resource extraction industries. To date, our ability to study deep-sea species lags behind that of those inhabiting the photic zone limiting scientific data available for management. In particular, knowledge of horizontal movements is restricted to two locations; capture and recapture, with no temporal information on absolute animal locations between endpoints. To elucidate the horizontal movements of a large deep-sea fish, a novel tagging approach was adopted using the smallest available prototype satellite tag - the mark-report pop-up archival tag (mrPAT). Five Greenland sharks (Somniosus microcephalus) were equipped with multiple mrPATs as well as a standard archival satellite tag (miniPAT) that were programmed to release in sequence at 8-10 day intervals. The performance of the mrPATs was quantified. The tagging approach provided multiple locations per individual and revealed a previously unknown directed migration of Greenland sharks from the Canadian high Arctic to Northwest Greenland. All tags reported locations, however, the accuracy and time from expected release were variable among tags (average time to an accurate location from expected release = 30.8 h, range: 4.9-227.6 h). Average mrPAT drift rate estimated from best quality messages (LQ1,2,3) was 0.37 ± 0.09 m/s indicating tags were on average 41.1 ± 63.4 km (range: 6.5-303.1 km) from the location of the animal when they transmitted. mrPATs provided daily temperature values that were highly correlated among tags and with the miniPAT (70.8% of tag pairs were significant). In contrast, daily tilt sensor data were variable among tags on the same animal (12.5% of tag pairs were significant). Tracking large-scale movements of deep-sea fish has historically been limited by the remote environment they inhabit. The current study provides a new approach to document reliable coarse scale horizontal movements to understand

  18. Técnicas moleculares para la detección e identificación de patógenos en alimentos: ventajas y limitaciones

    OpenAIRE

    Palomino-Camargo, Carolina; González-Muñoz, Yuniesky

    2014-01-01

    Las enfermedades transmitidas por alimentos, ocasionadas por microorganismos patógenos, constituyen un grave problema de salud pública a nivel mundial. Los métodos microbiológicos utilizados comúnmente en la detección de estos patógenos, de origen alimentario, son laboriosos y consume mucho tiempo. Esta situación, aunada a la demanda por resultados inmediatos y a los avances tecnológicos, ha conducido al desarrollo de una amplia gama de métodos rápidos en las últimas décadas. En base a esto, ...

  19. Bolt beam propagation analysis

    Science.gov (United States)

    Shokair, I. R.

    BOLT (Beam on Laser Technology) is a rocket experiment to demonstrate electron beam propagation on a laser ionized plasma channel across the geomagnetic field in the ion focused regime (IFR). The beam parameters for BOLT are: beam current I(sub b) = 100 Amps, beam energy of 1--1.5 MeV (gamma =3-4), and a Gaussian beam and channel of radii r(sub b) = r(sub c) = 1.5 cm. The N+1 ionization scheme is used to ionize atomic oxygen in the upper atmosphere. This scheme utilizes 130 nm light plus three IR lasers to excite and then ionize atomic oxygen. The limiting factor for the channel strength is the energy of the 130 nm laser, which is assumed to be 1.6 mJ for BOLT. At a fixed laser energy and altitude (fixing the density of atomic oxygen), the range can be varied by adjusting the laser tuning, resulting in a neutralization fraction axial profile of the form: f(z) = f(sub 0) e(exp minus z)/R, where R is the range. In this paper we consider the propagation of the BOLT beam and calculate the range of the electron beam taking into account the fact that the erosion rates (magnetic and inductive) vary with beam length as the beam and channel dynamically respond to sausage and hose instabilities.

  20. Direct numerical simulation of two-phases turbulent combustion: application to study of propagation and structure of flames; Simulation numerique directe de la combustion turbulente diphasique: application a l'etude de la propagation et de la structure des flammes

    Energy Technology Data Exchange (ETDEWEB)

    Canneviere, K.

    2003-12-15

    This work is devoted to the study of the propagation and the structure of two-phases turbulent flames. To this end, Direct Numerical Simulations (DNS) are used. First, numerical systems for two-phases flow simulations is presented along with a specific chemical model. Then, a study of laminar spray flames is carried out. An analytical study related to the dynamics of evaporation of droplets is first proposed where the influence on the equivalence ratio of the ratio between the heating delay of the droplet and the evaporation delay is detailed. The simulation of a propagating flame through a cloud of droplets is carried out and a pulsating behavior is highlighted. A study of these flames according to the topology of liquid fuel enabled us to characterize a double flame structure composed of a premixed flame and a diffusion flame. Our last study is devoted to spray turbulent flames. Two-phase combustion of turbulent jets has been simulated. By varying the spray injection parameters (density, equivalence ratio), a database has been generated. This database allowed us to describe local and global flame regimes appearing in the combustion of sprays. They have been categorized in four main structures: open and closed external regime, group combustion and mixed combustion. Eventually, a combustion diagram has been developed. It involves the spray vaporization time, the mean inter-space between droplets or group of droplets and eventually the injected equivalence ratio. (author)

  1. Tuning the interaction between propagating and localized surface plasmons for surface enhanced Raman scattering in water for biomedical and environmental applications

    Energy Technology Data Exchange (ETDEWEB)

    Shioi, Masahiko, E-mail: shioi.masahiko@jp.panasonic.com [Device Solutions Center, Panasonic Corporation, 3-4, Hikaridai, Seika-cho, Soraku-gun, Kyoto 619-0237 (Japan); Department of Electric and Electronic Engineering, Graduate School of Engineering, Kobe University, Rokkodai, Nada, Kobe 657-8501 (Japan); Jans, Hilde [Interuniversity Microelectronics Center VZW., Kapeldreef 75, 3001 Leuven (Belgium); Lodewijks, Kristof [Interuniversity Microelectronics Center VZW., Kapeldreef 75, 3001 Leuven (Belgium); Department of Electrical Engineering, Katholieke Universiteit Leuven, Celestijnenlaan 200 D, B-3001 Leuven (Belgium); Van Dorpe, Pol; Lagae, Liesbet [Interuniversity Microelectronics Center VZW., Kapeldreef 75, 3001 Leuven (Belgium); Department of Physics, Katholieke Universiteit Leuven, Celestijnenlaan 200 D, B-3001 Leuven (Belgium); Kawamura, Tatsuro [Device Solutions Center, Panasonic Corporation, 3-4, Hikaridai, Seika-cho, Soraku-gun, Kyoto 619-0237 (Japan)

    2014-06-16

    With a view to biomedical and environmental applications, we investigate the plasmonic properties of a rectangular gold nanodisk array in water to boost surface enhanced Raman scattering (SERS) effects. To control the resonance wavelengths of the surface plasmon polariton and the localized surface plasmon, their dependence on the array period and diameter in water is studied in detail using a finite difference time domain method. A good agreement is obtained between calculated resonant wavelengths and those of gold nanodisk arrays fabricated using electron beam lithography. For the optimized structure, a SERS enhancement factor of 7.8 × 10{sup 7} is achieved in water experimentally.

  2. Dāvināšana kā patērēšanas kultūras iezīme. Parfimērijas iegādes ietekmējošie faktori

    OpenAIRE

    Liepiņa, Krista

    2016-01-01

    Bakalaura darba “Dāvināšana kā patērēšanas kultūras iezīme. Parfimērijas iegādes ietekmējošie faktori” mērķis ir izpētīt, kas ir patērēšana un kas ietekmē patērētāju uzvedību ikdienā, kā arī svētku laikā, lēmuma pieņemšanas procesā, izvēloties preces dāvināšanas mērķim, nevis personīgai lietošanai. Darba teorētiskajā daļā apskatītas tādu jēdzienu teorētiskie aspekti kā patērēšana un patērniecība, patērēšanas kultūra, patērētāju uzvedība, patērētāju identitāte, kā arī tiek apskatīta dāvanu dāv...

  3. Impacto do Programa Água para Todos (PAT sobre a morbi-mortalidade por diarreia em crianças do Estado da Bahia, Brasil Impacto del Programa Agua para Todos (PAT sobre la morbimortalidad por diarrea en niños del Estado de Bahía, Brasil Impact of the Water for All Program (PAT on childhood morbidity and mortality from diarrhea in the Bahia State, Brazil

    Directory of Open Access Journals (Sweden)

    Davide Rasella

    2013-01-01

    Full Text Available O objetivo do presente estudo foi avaliar o impacto do Programa Água para Todos (PAT, implantado no Estado da Bahia, Brasil, por ampliar a cobertura do saneamento básico em áreas de maior vulnerabilidade. Foram selecionados 224 municípios com informações vitais adequadas. Foi utilizado um desenho de estudo antes-e-depois controlado, efetuando uma análise de regressão multivariada para dados em painel com resposta binomial negativa a efeitos fixos do ano 2005 até 2008. A cobertura do PAT, como variável contínua, esteve associada negativamente (p El objetivo del presente estudio fue evaluar el impacto del Programa Agua para Todos (PAT, implantado en el Estado de Bahía, Brasil, para ampliar la cobertura del saneamiento básico en áreas de mayor vulnerabilidad. Fueron seleccionados 224 municipios con información vital adecuada. Se utilizó un diseño de estudio antes-después controlado, efectuando un análisis de regresión multivariada para los datos en panel con respuesta binomial negativa, a efectos fijos del año 2005 hasta el 2008. La cobertura del PAT, como variable continua, estuvo asociada negativamente (p This study aimed to evaluate the impact of the Water for All Program (PAT, launched in Bahia State, Brazil, with the objective of expanding coverage of the water supply and sanitation in areas with high vulnerability to waterborne diseases. A total of 224 municipalities (counties with adequate vital statistics were selected. A controlled before-and-after study design was used, performing analyses with multivariate negative binomial regression with fixed effects, from 2005 to 2008. PAT coverage - as a continuous variable - was negatively associated (p < 0.01 with the under-five mortality rate. Municipalities with coverage ≥ 10% showed a reduction of 39% (p < 0.05 in mortality from diarrhea, under-five mortality of 14% (p < 0.01, and hospitalizations from diarrhea of 6% (p < 0.05 when compared to municipalities without PAT

  4. NASA Lunar Base Wireless System Propagation Analysis

    Science.gov (United States)

    Hwu, Shian U.; Upanavage, Matthew; Sham, Catherine C.

    2007-01-01

    There have been many radio wave propagation studies using both experimental and theoretical techniques over the recent years. However, most of studies have been in support of commercial cellular phone wireless applications. The signal frequencies are mostly at the commercial cellular and Personal Communications Service bands. The antenna configurations are mostly one on a high tower and one near the ground to simulate communications between a cellular base station and a mobile unit. There are great interests in wireless communication and sensor systems for NASA lunar missions because of the emerging importance of establishing permanent lunar human exploration bases. Because of the specific lunar terrain geometries and RF frequencies of interest to the NASA missions, much of the published literature for the commercial cellular and PCS bands of 900 and 1800 MHz may not be directly applicable to the lunar base wireless system and environment. There are various communication and sensor configurations required to support all elements of a lunar base. For example, the communications between astronauts, between astronauts and the lunar vehicles, between lunar vehicles and satellites on the lunar orbits. There are also various wireless sensor systems among scientific, experimental sensors and data collection ground stations. This presentation illustrates the propagation analysis of the lunar wireless communication and sensor systems taking into account the three dimensional terrain multipath effects. It is observed that the propagation characteristics are significantly affected by the presence of the lunar terrain. The obtained results indicate the lunar surface material, terrain geometry and antenna location are the important factors affecting the propagation characteristics of the lunar wireless systems. The path loss can be much more severe than the free space propagation and is greatly affected by the antenna height, surface material and operating frequency. The

  5. Propagators and path integrals

    Energy Technology Data Exchange (ETDEWEB)

    Holten, J.W. van

    1995-08-22

    Path-integral expressions for one-particle propagators in scalar and fermionic field theories are derived, for arbitrary mass. This establishes a direct connection between field theory and specific classical point-particle models. The role of world-line reparametrization invariance of the classical action and the implementation of the corresponding BRST-symmetry in the quantum theory are discussed. The presence of classical world-line supersymmetry is shown to lead to an unwanted doubling of states for massive spin-1/2 particles. The origin of this phenomenon is traced to a `hidden` topological fermionic excitation. A different formulation of the pseudo-classical mechanics using a bosonic representation of {gamma}{sub 5} is shown to remove these extra states at the expense of losing manifest supersymmetry. (orig.).

  6. Curvilinear crack layer propagation

    Science.gov (United States)

    Chudnovsky, Alexander; Chaoui, Kamel; Moet, Abdelsamie

    1987-01-01

    An account is given of an experiment designed to allow observation of the effect of damage orientation on the direction of crack growth in the case of crack layer propagation, using polystyrene as the model material. The direction of crack advance under a given loading condition is noted to be determined by a competition between the tendency of the crack to maintain its current direction and the tendency to follow the orientation of the crazes at its tip. The orientation of the crazes is, on the other hand, determined by the stress field due to the interaction of the crack, the crazes, and the hole. The changes in craze rotation relative to the crack define the active zone rotation.

  7. Atomistics of crack propagation

    International Nuclear Information System (INIS)

    Sieradzki, K.; Dienes, G.J.; Paskin, A.; Massoumzadeh, B.

    1988-01-01

    The molecular dynamic technique is used to investigate static and dynamic aspects of crack extension. The material chosen for this study was the 2D triangular solid with atoms interacting via the Johnson potential. The 2D Johnson solid was chosen for this study since a sharp crack in this material remains stable against dislocation emission up to the critical Griffith load. This behavior allows for a meaningful comparison between the simulation results and continuum energy theorems for crack extension by appropriately defining an effective modulus which accounts for sample size effects and the non-linear elastic behavior of the Johnson solid. Simulation results are presented for the stress fields of moving cracks and these dynamic results are discussed in terms of the dynamic crack propagation theories, of Mott, Eshelby, and Freund

  8. Broadband unidirectional ultrasound propagation

    Science.gov (United States)

    Sinha, Dipen N.; Pantea, Cristian

    2017-12-12

    A passive, linear arrangement of a sonic crystal-based apparatus and method including a 1D sonic crystal, a nonlinear medium, and an acoustic low-pass filter, for permitting unidirectional broadband ultrasound propagation as a collimated beam for underwater, air or other fluid communication, are described. The signal to be transmitted is first used to modulate a high-frequency ultrasonic carrier wave which is directed into the sonic crystal side of the apparatus. The apparatus processes the modulated signal, whereby the original low-frequency signal exits the apparatus as a collimated beam on the side of the apparatus opposite the sonic crystal. The sonic crystal provides a bandpass acoustic filter through which the modulated high-frequency ultrasonic signal passes, and the nonlinear medium demodulates the modulated signal and recovers the low-frequency sound beam. The low-pass filter removes remaining high-frequency components, and contributes to the unidirectional property of the apparatus.

  9. Propagation into an unstable state

    International Nuclear Information System (INIS)

    Dee, G.

    1985-01-01

    We describe propagating front solutions of the equations of motion of pattern-forming systems. We make a number of conjectures concerning the properties of such fronts in connection with pattern selection in these systems. We describe a calculation which can be used to calculate the velocity and state selected by certain types of propagating fronts. We investigate the propagating front solutions of the amplitude equation which provides a valid dynamical description of many pattern-forming systems near onset

  10. Bacillus cereus un patógeno importante en el control microbiológico de los alimentos / Bacillus cereus an important pathogen the microbiological control of food

    Directory of Open Access Journals (Sweden)

    Jennifer Sánchez

    2016-05-01

    Full Text Available Resumen Bacillus cereus es una bacteria genéticamente diversa que se encuentra comúnmente en el ambiente. Contamina los alimentos afectando la salud humana, al ingerir el microorganismo y/o sus toxinas, la emética o las enterotoxinas. En Colombia son escasos los reportes de intoxicación por B. cereus y se estima que hay un gran subregistro. Por lo anterior, se recomienda aumentar la vigilancia de este patógeno y realizar estudios sobre aspectos relevantes que permitan aplicar medidas de control para disminuir las intoxicaciones por B. cereus. El objetivo de esta revisión bibliográfica es presentar información actualizada sobre B. cereus, que incluye aspectos de su biología, taxonomía, toxinas, alimentos que contamina y metodologías para detectar, prevenir y controlar este microorganismo. La información presentada es de utilidad para el público en general, especialmente personas vinculadas al sector de alimentos, inocuidad alimentaria y control de procesos. / Abstract Bacillus cereus is a genetically diverse bacterium commonly found in the environment. It contaminates food, thus affecting human health upon ingestion of the microorganism and/or its toxins, the emetic or enterotoxins. In Colombia, reports of intoxication by B. cereus are scarce and under-registration is presumed. Because of this, it is recommended to increase surveillance of this pathogen and to develop studies on relevant aspects that allow the application of control measures to reduce intoxications by B. cereus. The aim of this review is to present current information on B. cereus, including aspects of its biology, taxonomy, toxins, food that it contaminates and methodologies for the detection, prevention and control of this microorganism. This information is useful for the general public, especially people involved with the food sector, food safety and process control.

  11. Anotaciones sobre el Clima de los Bosques de Guandal del Delta del Río Patía

    Directory of Open Access Journals (Sweden)

    Del Valle Arango Jorge Ignacio

    1994-09-01

    Full Text Available Este ensayo intenta describir el clima del litoral Pacifico sur colombiano de una manera más precisa y empleando un cúmulo mayor de registros que en otros trabajos anteriores. Con esta base se realiza una clasificación bioclimática para los bosques de guandal del delta del río Patía. En cuanto a la lluvia se hace énfasis no sólo en los promedios mensuales y anuales sino en su oscilación y desviaciones estándar con el fin de evidenciar lo variable de tan importante factor climático. Finalmente se elaboran isoyetas para la región las cuales consideramos consistentes con la información disponible.

  12. Feynman propagator in curved space-time

    International Nuclear Information System (INIS)

    Candelas, P.; Raine, D.J.

    1977-01-01

    The Wick rotation is generalized in a covariant manner so as to apply to curved manifolds in a way that is independent of the analytic properties of the manifold. This enables us to show that various methods for defining a Feynman propagator to be found in the literature are equivalent where they are applicable. We are also able to discuss the relation between certain regularization methods that have been employed

  13. Prevenção da transmissão de patógenos por manipuladores de alimentos

    Directory of Open Access Journals (Sweden)

    Mirza de Souza Conceição

    2015-03-01

    Full Text Available O objetivo desta pesquisa foi investigar as formas de prevenção da transmissão de patógeno por manipuladores de alimentos. Este trabalho utilizou uma abordagem qualitativa, mediante uma pesquisa bibliográfica, utilizando dados secundários oriundos de publicações e resultados de pesquisas específicas sobre o assunto realizando uma síntese explicativa sobre a prevenção da transmissão de patógenos por manipuladores de alimentos. As doenças transmitidas por alimentos é uma preocupação de saúde pública a nível mundial. E dentre agentes mais frequentes causadores de DTA’s estão os microrganismos de origem bacteriana como, a Salmonella spp, Escherichia coli, Staphylococcus aureus, Shigella spp, Bacillus cereus e Clostridium perfringens e destacam-se os alimentos de origem animal. Cabe destacar que a maioria dos manipuladores de alimentos necessita de maiores informações relacionadas à qualidade higiênica sanitária durante a fabricação dos produtos, e uma das maneiras de fornecer alimentos seguros é a realização de programas de educação continuada para esses profissionais. Conclui-se que o treinamento dos manipuladores de alimentos ainda é a melhor forma de contribuir para que estas pessoas se conscientizem sobre a sua responsabilidade e tenham cuidado no processamento do alimento.

  14. A Process Analytical Technology (PAT) approach to control a new API manufacturing process: development, validation and implementation.

    Science.gov (United States)

    Schaefer, Cédric; Clicq, David; Lecomte, Clémence; Merschaert, Alain; Norrant, Edith; Fotiadu, Frédéric

    2014-03-01

    Pharmaceutical companies are progressively adopting and introducing Process Analytical Technology (PAT) and Quality-by-Design (QbD) concepts promoted by the regulatory agencies, aiming the building of the quality directly into the product by combining thorough scientific understanding and quality risk management. An analytical method based on near infrared (NIR) spectroscopy was developed as a PAT tool to control on-line an API (active pharmaceutical ingredient) manufacturing crystallization step during which the API and residual solvent contents need to be precisely determined to reach the predefined seeding point. An original methodology based on the QbD principles was designed to conduct the development and validation of the NIR method and to ensure that it is fitted for its intended use. On this basis, Partial least squares (PLS) models were developed and optimized using chemometrics methods. The method was fully validated according to the ICH Q2(R1) guideline and using the accuracy profile approach. The dosing ranges were evaluated to 9.0-12.0% w/w for the API and 0.18-1.50% w/w for the residual methanol. As by nature the variability of the sampling method and the reference method are included in the variability obtained for the NIR method during the validation phase, a real-time process monitoring exercise was performed to prove its fit for purpose. The implementation of this in-process control (IPC) method on the industrial plant from the launch of the new API synthesis process will enable automatic control of the final crystallization step in order to ensure a predefined quality level of the API. In addition, several valuable benefits are expected including reduction of the process time, suppression of a rather difficult sampling and tedious off-line analyses. © 2013 Published by Elsevier B.V.

  15. Short-term effects of a dung pat on N2 fixation and total N uptake in a perennial ryegrass/white clover mixture

    DEFF Research Database (Denmark)

    Jørgensen, F.V.; Jensen, E.S.

    1997-01-01

    The short-term effects of a simulated cattle dung pat on N-2 fixation and total uptake of N in a perennial ryegrass/white clover mixture was studied in a container experiment using sheep faeces mixed with water to a DM content of 13%. We used a new N-15 cross-labelling technique to determine...

  16. Dual RNA Processing Roles of Pat1b via Cytoplasmic Lsm1-7 and Nuclear Lsm2-8 Complexes

    Directory of Open Access Journals (Sweden)

    Caroline Vindry

    2017-08-01

    Full Text Available Pat1 RNA-binding proteins, enriched in processing bodies (P bodies, are key players in cytoplasmic 5′ to 3′ mRNA decay, activating decapping of mRNA in complex with the Lsm1-7 heptamer. Using co-immunoprecipitation and immunofluorescence approaches coupled with RNAi, we provide evidence for a nuclear complex of Pat1b with the Lsm2-8 heptamer, which binds to the spliceosomal U6 small nuclear RNA (snRNA. Furthermore, we establish the set of interactions connecting Pat1b/Lsm2-8/U6 snRNA/SART3 and additional U4/U6.U5 tri-small nuclear ribonucleoprotein particle (tri-snRNP components in Cajal bodies, the site of snRNP biogenesis. RNA sequencing following Pat1b depletion revealed the preferential upregulation of mRNAs normally found in P bodies and enriched in 3′ UTR AU-rich elements. Changes in >180 alternative splicing events were also observed, characterized by skipping of regulated exons with weak donor sites. Our data demonstrate the dual role of a decapping enhancer in pre-mRNA processing as well as in mRNA decay via distinct nuclear and cytoplasmic Lsm complexes.

  17. Wave Propagation in Jointed Geologic Media

    Energy Technology Data Exchange (ETDEWEB)

    Antoun, T

    2009-12-17

    Predictive modeling capabilities for wave propagation in a jointed geologic media remain a modern day scientific frontier. In part this is due to a lack of comprehensive understanding of the complex physical processes associated with the transient response of geologic material, and in part it is due to numerical challenges that prohibit accurate representation of the heterogeneities that influence the material response. Constitutive models whose properties are determined from laboratory experiments on intact samples have been shown to over-predict the free field environment in large scale field experiments. Current methodologies for deriving in situ properties from laboratory measured properties are based on empirical equations derived for static geomechanical applications involving loads of lower intensity and much longer durations than those encountered in applications of interest involving wave propagation. These methodologies are not validated for dynamic applications, and they do not account for anisotropic behavior stemming from direcitonal effects associated with the orientation of joint sets in realistic geologies. Recent advances in modeling capabilities coupled with modern high performance computing platforms enable physics-based simulations of jointed geologic media with unprecedented details, offering a prospect for significant advances in the state of the art. This report provides a brief overview of these modern computational approaches, discusses their advantages and limitations, and attempts to formulate an integrated framework leading to the development of predictive modeling capabilities for wave propagation in jointed and fractured geologic materials.

  18. Application of hepatitis B core particles produced by human primary hepatocellular carcinoma (PLC/342) propagated in nude mice to the determination of anti-HBc by passive hemagglutination.

    Science.gov (United States)

    Miyamoto, K; Itoh, Y; Tsuda, F; Matsui, T; Tanaka, T; Miyamoto, H; Naitoh, S; Imai, M; Usuda, S; Nakamura, T

    1986-05-22

    Human primary hepatocellular carcinoma (PLC/342), carried by nude mice, produces hepatitis B core particles as well as hepatitis B surface antigen particles. Core particles purified form PLC/342 tumors displayed epitopes of hepatitis B core antigen (HBcAg) but not epitopes of hepatitis B e antigen (HBeAg) on their surface, unlike core particles prepared from Dane particles, derived from plasma of asymptomatic carriers, that expressed epitopes of both HBcAg and HBeAg. Core particles obtained from PLC/342 tumors were applied to the determination of antibody to HBcAg (anti-HBc) by passive hemagglutination. The assay detected anti-HBc not only in individuals with persistent infection with hepatitis B virus and in those who had recovered from transient infection, but also in patients with acute type B hepatitis, indicating that it can detect anti-HBc of either IgG or IgM class. A liberal availability of core particles from tumors carried by nude mice, taken together with an easy applicability of the method, would make the passive hemagglutination for anti-HBc a valuable tool in clinical and epidemiological studies, especially in places where sophisticated methods are not feasible.

  19. The parabolic equation method for outdoor sound propagation

    DEFF Research Database (Denmark)

    Arranz, Marta Galindo

    The parabolic equation method is a versatile tool for outdoor sound propagation. The present study has focused on the Cranck-Nicolson type Parabolic Equation method (CNPE). Three different applications of the CNPE method have been investigated. The first two applications study variations of the g......The parabolic equation method is a versatile tool for outdoor sound propagation. The present study has focused on the Cranck-Nicolson type Parabolic Equation method (CNPE). Three different applications of the CNPE method have been investigated. The first two applications study variations...

  20. Propagating annular modes

    Science.gov (United States)

    Sheshadri, A.; Plumb, R. A.

    2017-12-01

    The leading "annular mode", defined as the dominant EOF of surface pressure or of zonal mean zonal wind variability, appears as a dipolar structure straddling the mean midlatitude jet and thus seems to describe north-south wobbling of the jet latitude. However, extratropical zonal wind anomalies frequently tend to migrate poleward. This behavior can be described by the first two EOFs, the first (AM1) being the dipolar structure, and the second (AM2) having a tripolar structure centered on the mean jet. Taken in isolation, AM1 thus describes a north-south wobbling of the jet position, while AM2 describes a strengthening and narrowing of the jet. However, despite the fact that they are spatially orthogonal, and their corresponding time series temporally orthogonal, AM1 and AM2 are not independent, but show significant lag-correlations which reveal the propagation. The EOFs are not modes of the underlying dynamical system governing the zonal flow evolution. The true modes can be estimated using principal oscillation pattern (POP) analysis. In the troposphere, the leading POPs manifest themselves as a pair of complex conjugate structures with conjugate eigenvalues thus, in reality, constituting a single, complex, mode that describes propagating anomalies. Even though the principal components associated with the two leading EOFs decay at different rates, each decays faster than the true mode. These facts have implications for eddy feedback and the susceptibility of the mode to external perturbations. If one interprets the annular modes as the modes of the system, then simple theory predicts that the response to steady forcing will usually be dominated by AM1 (with the longest time scale). However, such arguments should really be applied to the true modes. Experiments with a simplified GCM show that climate response to perturbations do not necessarily have AM1 structures. Implications of these results for stratosphere-troposphere interactions are explored. The POP

  1. Efficient Geometric Sound Propagation Using Visibility Culling

    Science.gov (United States)

    Chandak, Anish

    2011-07-01

    Simulating propagation of sound can improve the sense of realism in interactive applications such as video games and can lead to better designs in engineering applications such as architectural acoustics. In this thesis, we present geometric sound propagation techniques which are faster than prior methods and map well to upcoming parallel multi-core CPUs. We model specular reflections by using the image-source method and model finite-edge diffraction by using the well-known Biot-Tolstoy-Medwin (BTM) model. We accelerate the computation of specular reflections by applying novel visibility algorithms, FastV and AD-Frustum, which compute visibility from a point. We accelerate finite-edge diffraction modeling by applying a novel visibility algorithm which computes visibility from a region. Our visibility algorithms are based on frustum tracing and exploit recent advances in fast ray-hierarchy intersections, data-parallel computations, and scalable, multi-core algorithms. The AD-Frustum algorithm adapts its computation to the scene complexity and allows small errors in computing specular reflection paths for higher computational efficiency. FastV and our visibility algorithm from a region are general, object-space, conservative visibility algorithms that together significantly reduce the number of image sources compared to other techniques while preserving the same accuracy. Our geometric propagation algorithms are an order of magnitude faster than prior approaches for modeling specular reflections and two to ten times faster for modeling finite-edge diffraction. Our algorithms are interactive, scale almost linearly on multi-core CPUs, and can handle large, complex, and dynamic scenes. We also compare the accuracy of our sound propagation algorithms with other methods. Once sound propagation is performed, it is desirable to listen to the propagated sound in interactive and engineering applications. We can generate smooth, artifact-free output audio signals by applying

  2. Propagation of Ion Acoustic Perturbations

    DEFF Research Database (Denmark)

    Pécseli, Hans

    1975-01-01

    Equations describing the propagation of ion acoustic perturbations are considered, using the assumption that the electrons are Boltzman distributed and isothermal at all times. Quasi-neutrality is also considered.......Equations describing the propagation of ion acoustic perturbations are considered, using the assumption that the electrons are Boltzman distributed and isothermal at all times. Quasi-neutrality is also considered....

  3. Propagation Engineering in Wireless Communications

    CERN Document Server

    Ghasemi, Abdollah; Ghasemi, Farshid

    2012-01-01

    Wireless communications has seen explosive growth in recent decades, in a realm that is both broad and rapidly expanding to include satellite services, navigational aids, remote sensing, telemetering, audio and video broadcasting, high-speed data communications, mobile radio systems and much more. Propagation Engineering in Wireless Communications deals with the basic principles of radiowaves propagation for frequency bands used in radio-communications, offering descriptions of new achievements and newly developed propagation models. The book bridges the gap between theoretical calculations and approaches, and applied procedures needed for advanced radio links design. The primary objective of this two-volume set is to demonstrate the fundamentals, and to introduce propagation phenomena and mechanisms that engineers are likely to encounter in the design and evaluation of radio links of a given type and operating frequency. Volume one covers basic principles, along with tropospheric and ionospheric propagation,...

  4. Transionospheric propagation predictions

    Science.gov (United States)

    Klobucher, J. A.; Basu, S.; Basu, S.; Bernhardt, P. A.; Davies, K.; Donatelli, D. E.; Fremouw, E. J.; Goodman, J. M.; Hartmann, G. K.; Leitinger, R.

    1979-01-01

    The current status and future prospects of the capability to make transionospheric propagation predictions are addressed, highlighting the effects of the ionized media, which dominate for frequencies below 1 to 3 GHz, depending upon the state of the ionosphere and the elevation angle through the Earth-space path. The primary concerns are the predictions of time delay of signal modulation (group path delay) and of radio wave scintillation. Progress in these areas is strongly tied to knowledge of variable structures in the ionosphere ranging from the large scale (thousands of kilometers in horizontal extent) to the fine scale (kilometer size). Ionospheric variability and the relative importance of various mechanisms responsible for the time histories observed in total electron content (TEC), proportional to signal group delay, and in irregularity formation are discussed in terms of capability to make both short and long term predictions. The data base upon which predictions are made is examined for its adequacy, and the prospects for prediction improvements by more theoretical studies as well as by increasing the available statistical data base are examined.

  5. Dressing the nucleon propagator

    International Nuclear Information System (INIS)

    Fishman, S.; Gersten, A.

    1976-01-01

    The nucleon propagator in the ''nested bubbles'' approximation is analyzed. The approximation is built from the minimal set of diagrams which is needed to maintain the unitarity condition under two-pion production threshold in the two-nucleon Bethe--Salpeter equation. Recursive formulas for subsets of ''nested bubbles'' diagrams calculated in the framework of the pseudoscalar interaction are obtained by the use of dispersion relations. We prove that the sum of all the ''nested bubbles'' diverges. Moreover, the successive iterations are plagued with ghost poles. We prove that the first approximation--which is the so-called chain approximation--has ghost poles for any nonvanishing coupling constant. In an earlier paper we have shown that ghost poles lead to ghost cuts. These cuts are present in the ''nested bubbles.'' Ghost elimination procedures are discussed. Modifications of the ''nested bubbles'' approximation are introduced in order to obtain convergence and in order to eliminate the ghost poles and ghost cuts. In a similar way as in the Lee model, cutoff functions are introduced in order to eliminate the ghost poles. The necessary and sufficient conditions for the absence of ghost poles are formulated and analyzed. The spectral functions of the modified ''nested bubbles'' are analyzed and computed. Finally, we present a theorem, similar in its form to Levinson's theorem in scattering theory, which enables one to compute in a simple way the number of ghost poles

  6. A simple three dimensional wide-angle beam propagation method

    Science.gov (United States)

    Ma, Changbao; van Keuren, Edward

    2006-05-01

    The development of three dimensional (3-D) waveguide structures for chip scale planar lightwave circuits (PLCs) is hampered by the lack of effective 3-D wide-angle (WA) beam propagation methods (BPMs). We present a simple 3-D wide-angle beam propagation method (WA-BPM) using Hoekstra’s scheme along with a new 3-D wave equation splitting method. The applicability, accuracy and effectiveness of our method are demonstrated by applying it to simulations of wide-angle beam propagation and comparing them with analytical solutions.

  7. Design Against Propagating Shear Failure in Pipelines

    Science.gov (United States)

    Leis, B. N.; Gray, J. Malcolm

    Propagating shear failure can occur in gas and certain hazardous liquid transmission pipelines, potentially leading to a large long-burning fire and/or widespread pollution, depending on the transported product. Such consequences require that the design of the pipeline and specification of the steel effectively preclude the chance of propagating shear failure. Because the phenomenology of such failures is complex, design against such occurrences historically has relied on full-scale demonstration experiments coupled with empirically calibrated analytical models. However, as economic drivers have pushed toward larger diameter higher pressure pipelines made of tough higher-strength grades, the design basis to ensure arrest has been severely compromised. Accordingly, for applications where the design basis becomes less certain, as has occurred increasing as steel grade and toughness has increased, it has become necessary to place greater reliance on the use and role of full-scale testing.

  8. M2 qualify laser beam propagation

    International Nuclear Information System (INIS)

    Abdelhalim, Bencheikh; Mohamed, Bouafia

    2010-01-01

    One of the most important properties of a laser resonator is the highly collimated or spatially coherent nature of the laser output beam. Laser beam diameter and quality factor M 2 are significant parameters in a wide range of laser applications. This is because the spatial beam quality determines how closely the beam can be focused or how well the beam propagates over long distances without significant dispersion. In the present paper we have used three different methods to qualify the spatial structure of a laser beam propagating in free space, the results are obtained and discussed, and we have found that the Wigner distribution function is a powerful tool which allows a global characterization of any kind of beam

  9. Topology optimization of vibration and wave propagation problems

    DEFF Research Database (Denmark)

    Jensen, Jakob Søndergaard

    2007-01-01

    The method of topology optimization is a versatile method to determine optimal material layouts in mechanical structures. The method relies on, in principle, unlimited design freedom that can be used to design materials, structures and devices with significantly improved performance and sometimes...... novel functionality. This paper addresses basic issues in simulation and topology design of vibration and wave propagation problems. Steady-state and transient wave propagation problems are addressed and application examples for both cases are presented....

  10. Laser beam propagation generation and propagation of customized light

    CERN Document Server

    Forbes, Andrew

    2014-01-01

    ""The text is easy to read and is accompanied by beautiful illustrations. It is an excellent book for anyone working in laser beam propagation and an asset for any library.""-Optics & Photonics News, July 2014

  11. Computer modeling of inelastic wave propagation in porous rock

    International Nuclear Information System (INIS)

    Cheney, J.A.; Schatz, J.F.; Snell, C.

    1979-01-01

    Computer modeling of wave propagation in porous rock has several important applications. Among them are prediction of fragmentation and permeability changes to be caused by chemical explosions used for in situ resource recovery, and the understanding of nuclear explosion effects such as seismic wave generation, containment, and site hardness. Of interest in all these applications are the distance from the source to which inelastic effects persist and the amount of porosity change within the inelastic region. In order to study phenomena related to these applications, the Cam Clay family of models developed at Cambridge University was used to develop a similar model that is applicable to wave propagation in porous rock. That model was incorporated into a finite-difference wave propagation computer code SOC. 10 figures, 1 table

  12. Applications, benefits and challenges of flow chemistry

    DEFF Research Database (Denmark)

    Mitic, Aleksandar; Heintz, Søren; Ringborg, Rolf Hoffmeyer

    2013-01-01

    , environmental and manufacturing perspective. A potential solution to resolve these issues is to use flow chemistry in such processes, preferably with applications of micro-and mini-sized equipment. In addition, Process Analytical Technology (PAT) may be implemented in a very efficient way in such equipment due...

  13. Efficacy and Safety of Tranexamic Acid in Prehospital Traumatic Hemorrhagic Shock: Outcomes of the Cal-PAT Study

    Directory of Open Access Journals (Sweden)

    Michael M. Neeki

    2017-04-01

    Full Text Available Introduction: The California Prehospital Antifibrinolytic Therapy (Cal-PAT study seeks to assess the safety and impact on patient mortality of tranexamic acid (TXA administration in cases of trauma-induced hemorrhagic shock. The current study further aimed to assess the feasibility of prehospital TXA administration by paramedics within the framework of North American emergency medicine standards and protocols. Methods: This is an ongoing multi-centered, prospective, observational cohort study with a retrospective chart-review comparison. Trauma patients identified in the prehospital setting with signs of hemorrhagic shock by first responders were administered one gram of TXA followed by an optional second one-gram dose upon arrival to the hospital, if the patient still met inclusion criteria. Patients administered TXA make up the prehospital intervention group. Control group patients met the same inclusion criteria as TXA candidates and were matched with the prehospital intervention patients based on mechanism of injury, injury severity score, and age. The primary outcomes were mortality, measured at 24 hours, 48 hours, and 28 days. Secondary outcomes measured included the total blood products transfused and any known adverse events associated with TXA administration. Results: We included 128 patients in the prehospital intervention group and 125 in the control group. Although not statistically significant, the prehospital intervention group trended toward a lower 24-hour mortality rate (3.9% vs 7.2% for intervention and control, respectively, p=0.25, 48-hour mortality rate (6.3% vs 7.2% for intervention and control, respectively, p=0.76, and 28-day mortality rate (6.3% vs 10.4% for intervention and control, respectively, p=0.23. There was no significant difference observed in known adverse events associated with TXA administration in the prehospital intervention group and control group. A reduction in total blood product usage was observed

  14. RIMAP demonstration project. Pat. 1: Risk based life management of piping system in power plant Heilbronn

    International Nuclear Information System (INIS)

    Bareiss, J.; Puck, P.; Matschecko, B.; Jovanovic, A.; Balos, D.; Perunicic

    2003-01-01

    In the framework of EU project RIMAP [1] a new European Guideline for optimized risk based maintenance and inspection planning of industrial plants (RBLM - Risk Based Life Management) is being developed. The RIMAP project consists of the three clustered projects: development (RTD), demonstration (DEMO) and thematic network (TN). Current work and future, planned work in RIMAP demonstration project on applications of the RIMAP methodology in power plants are presented briefly in the first part of the paper. Also presented in the paper are the results of a preliminary analysis of piping system in power plant Heilbronn using the concept of risk-based monitoring as part of overall concept of risk-based life management. Shortly the following issues are discussed in the paper: identification of critical components, application of a multilevel risk analysis (..from ''screening'' to ''detailed analysis''), determination of PoF - Probability of Failure, determination of COF - Consequence of Failure and optimation of inspection and maintenance plan. (orig.)

  15. Study on the electromagnetic waves propagation characteristics in partially ionized plasma slabs

    Directory of Open Access Journals (Sweden)

    Zhi-Bin Wang

    2016-05-01

    Full Text Available Propagation characteristics of electromagnetic (EM waves in partially ionized plasma slabs are studied in this paper. Such features are significant to applications in plasma antennas, blackout of re-entry flying vehicles, wave energy injection to plasmas, and etc. We in this paper developed a theoretical model of EM wave propagation perpendicular to a plasma slab with a one-dimensional density inhomogeneity along propagation direction to investigate essential characteristics of EM wave propagation in nonuniform plasmas. Particularly, the EM wave propagation in sub-wavelength plasma slabs, where the geometric optics approximation fails, is studied and in comparison with thicker slabs where the geometric optics approximation applies. The influences of both plasma and collisional frequencies, as well as the width of the plasma slab, on the EM wave propagation characteristics are discussed. The results can help the further understanding of propagation behaviours of EM waves in nonuniform plasma, and applications of the interactions between EM waves and plasmas.

  16. Visual attitude propagation for small satellites

    Science.gov (United States)

    Rawashdeh, Samir A.

    As electronics become smaller and more capable, it has become possible to conduct meaningful and sophisticated satellite missions in a small form factor. However, the capability of small satellites and the range of possible applications are limited by the capabilities of several technologies, including attitude determination and control systems. This dissertation evaluates the use of image-based visual attitude propagation as a compliment or alternative to other attitude determination technologies that are suitable for miniature satellites. The concept lies in using miniature cameras to track image features across frames and extracting the underlying rotation. The problem of visual attitude propagation as a small satellite attitude determination system is addressed from several aspects: related work, algorithm design, hardware and performance evaluation, possible applications, and on-orbit experimentation. These areas of consideration reflect the organization of this dissertation. A "stellar gyroscope" is developed, which is a visual star-based attitude propagator that uses relative motion of stars in an imager's field of view to infer the attitude changes. The device generates spacecraft relative attitude estimates in three degrees of freedom. Algorithms to perform the star detection, correspondence, and attitude propagation are presented. The Random Sample Consensus (RANSAC) approach is applied to the correspondence problem to successfully pair stars across frames while mitigating falsepositive and false-negative star detections. This approach provides tolerance to the noise levels expected in using miniature optics and no baffling, and the noise caused by radiation dose on orbit. The hardware design and algorithms are validated using test images of the night sky. The application of the stellar gyroscope as part of a CubeSat attitude determination and control system is described. The stellar gyroscope is used to augment a MEMS gyroscope attitude propagation

  17. Methodologies of Uncertainty Propagation Calculation

    International Nuclear Information System (INIS)

    Chojnacki, Eric

    2002-01-01

    After recalling the theoretical principle and the practical difficulties of the methodologies of uncertainty propagation calculation, the author discussed how to propagate input uncertainties. He said there were two kinds of input uncertainty: - variability: uncertainty due to heterogeneity, - lack of knowledge: uncertainty due to ignorance. It was therefore necessary to use two different propagation methods. He demonstrated this in a simple example which he generalised, treating the variability uncertainty by the probability theory and the lack of knowledge uncertainty by the fuzzy theory. He cautioned, however, against the systematic use of probability theory which may lead to unjustifiable and illegitimate precise answers. Mr Chojnacki's conclusions were that the importance of distinguishing variability and lack of knowledge increased as the problem was getting more and more complex in terms of number of parameters or time steps, and that it was necessary to develop uncertainty propagation methodologies combining probability theory and fuzzy theory

  18. Propagation engineering in wireless communications

    CERN Document Server

    Ghasemi, Abdollah; Ghasemi, Farshid

    2016-01-01

    This book covers the basic principles for understanding radio wave propagation for common frequency bands used in radio-communications. This includes achievements and developments in propagation models for wireless communication. This book is intended to bridge the gap between the theoretical calculations and approaches to the applied procedures needed for radio links design in a proper manner. The authors emphasize propagation engineering by giving fundamental information and explain the use of basic principles together with technical achievements. This new edition includes additional information on radio wave propagation in guided media and technical issues for fiber optics cable networks with several examples and problems. This book also includes a solution manual - with 90 solved examples distributed throughout the chapters - and 158 problems including practical values and assumptions.

  19. Wave propagation in electromagnetic media

    CERN Document Server

    Davis, Julian L

    1990-01-01

    This is the second work of a set of two volumes on the phenomena of wave propagation in nonreacting and reacting media. The first, entitled Wave Propagation in Solids and Fluids (published by Springer-Verlag in 1988), deals with wave phenomena in nonreacting media (solids and fluids). This book is concerned with wave propagation in reacting media-specifically, in electro­ magnetic materials. Since these volumes were designed to be relatively self­ contained, we have taken the liberty of adapting some of the pertinent material, especially in the theory of hyperbolic partial differential equations (concerned with electromagnetic wave propagation), variational methods, and Hamilton-Jacobi theory, to the phenomena of electromagnetic waves. The purpose of this volume is similar to that of the first, except that here we are dealing with electromagnetic waves. We attempt to present a clear and systematic account of the mathematical methods of wave phenomena in electromagnetic materials that will be readily accessi...

  20. Massive propagators in instanton fields

    International Nuclear Information System (INIS)

    Brown, L.S.; Lee, C.

    1978-01-01

    Green's functions for massive spinor and vector particles propagating in a self-dual but otherwise arbitrary non-Abelian gauge field are shown to be completely determined by the corresponding Green's functions of massive scalar particles

  1. Laser Beam Propagation Through Inhomogeneous Media with Shock-Like Profiles: Modeling and Computing

    Science.gov (United States)

    Adamovsky, Grigory; Ida, Nathan

    1997-01-01

    Wave propagation in inhomogeneous media has been studied for such diverse applications as propagation of radiowaves in atmosphere, light propagation through thin films and in inhomogeneous waveguides, flow visualization, and others. In recent years an increased interest has been developed in wave propagation through shocks in supersonic flows. Results of experiments conducted in the past few years has shown such interesting phenomena as a laser beam splitting and spreading. The paper describes a model constructed to propagate a laser beam through shock-like inhomogeneous media. Numerical techniques are presented to compute the beam through such media. The results of computation are presented, discussed, and compared with experimental data.

  2. The effectiveness of CPI model to improve positive attitude toward science (PATS) for pre-service physics teacher

    Science.gov (United States)

    Sunarti, T.; Wasis; Madlazim; Suyidno; Prahani, B. K.

    2018-03-01

    In the previous research, learning material based Construction, Production, and Implementation (CPI) model has been developed to improve scientific literacy and positive attitude toward science for pre-service physics teacher. CPI model has 4 phases, included: 1) Motivation; 2) Construction (Cycle I); 3) Production (Cycle II); and 4) Evaluation. This research is aimed to analyze the effectiveness of CPI model towards the improvement Positive Attitude toward Science (PATS) for pre-service physics teacher. This research used one group pre-test and post-test design on 160 pre-service physics teacher divided into 4 groups at Lambung Mangkurat University and Surabaya State University (Indonesia), academic year 2016/2017. Data collection was conducted through questioner, observation, and interview. Positive attitude toward science for pre-service physics teacher measurement were conducted through Positive Attitude toward Science Evaluation Sheet (PATSES). The data analysis technique was done by using Wilcoxon test and n-gain. The results showed that there was a significant increase in positive attitude toward science for pre-service physics teacher at α = 5%, with n-gain average of high category. Thus, the CPI model is effective for improving positive attitude toward science for pre-service physics teacher.

  3. [Status of diagnosis and treatment devices of acupuncture based on SooPAT and bibliometrics in China].

    Science.gov (United States)

    Bai, Lin; Ren, Yulan; Guo, Taipin; Chen, Lin; Zhou, Yumei; Feng, Shuwei; Li, Ji; Liang, Fanrong

    2016-11-12

    To perform a bibliometrics analysis on patent literature regarding diagnosis and treatment devices of acupuncture in China, aiming to provide references for the development of diagnosis and treatment devices of acupuncture. Based on SooPAT, a patent database, the patent literature regarding diagnosis and treatment devices of acupuncture in China was collected. With bibliometrics methods, the annual distribution of type, quantity, classification and content of diagnosis and treatment devices of acupuncture were analyzed. The number of acupuncture diagnosis and treatment devices reached its peak in 2012 and 2013 in China. The A61N in patent and utility model patent were the most, which were mainly related to electrotherapy, magnetic therapy, radioactive therapy and ultrasound therapy, etc. The main content was acupuncture treatment devices and meridian treatment devices. The 24-01 in design patent was the most, involving fixation devices used by doctors, hospitals and laboratories, etc. Currently the majority of diagnosis and treatment devices of acupuncture is therapeutic apparatus, while the acupuncture diagnosis devices are needed.

  4. Morfologia de Plântulas e Controle de Patógenos em Sementes de Cordia trichotoma

    Directory of Open Access Journals (Sweden)

    Álvaro Luis Pasquetti Berghetti

    Full Text Available O presente trabalho tem como objetivo descrever morfologicamente o desenvolvimento das plântulas de Cordia trichotoma, determinar a influência dos tratamentos de semente e do substrato na redução da incidência de patógenos, assim como avaliar o potencial germinativo das sementes. O teste de sanidade foi realizado em esquema bifatorial 2 × 4 (dois tipos de beneficiamento e quatro tratamentos de sementes. O teste de germinação representou um esquema trifatorial 2 × 4 × 3 (dois beneficiamentos, quatro tratamentos de sementes e três substratos. O início da germinação ocorreu no 18° dia após a instalação do teste. A germinação das sementes é do tipo epígea, com plântula fanerocotiledonar. O percentual germinativo das sementes é superior quando é retirado todo o perianto, independentemente do substrato utilizado e do tratamento. O tratamento com Captan® reduziu a incidência de fungos dos gêneros Alternaria spp., Trichoderma spp., Rhizopus spp.

  5. A PAT approach for the on-line monitoring of pharmaceutical co-crystals formation with near infrared spectroscopy.

    Science.gov (United States)

    Sarraguça, Mafalda C; Ribeiro, Paulo R S; Santos, Adenilson O; Silva, Marta C D; Lopes, João A

    2014-08-25

    Cocrystals represent a class of crystalline solids consisting of two or more molecular species usually held together by non-covalent bonds. Pharmaceutical cocrystals can alter the physicochemical properties of the active pharmaceutical ingredient to improve solubility, dissolution rate, particle properties and stability. This work presents a process analytical technology (PAT) approach to monitor on-line the cocrystallization of furosemide and adenine by solvent evaporation using near infrared spectroscopy (NIRS). Furosemide and adenine were added to a small volume of methanol in a beaker and stirred on an orbital stirring table during 8h at room temperature. The on-line monitoring was performed with a FT-NIR spectrometer fitted with a reflectance fiber optic probe. Monitoring was performed with the probe tip placed 1cm above the cocrystallization medium to avoid interference with the cocrystallization process. Cocrystals were vacuum dried to remove residual solvent and characterized off-line by NIRS, MIRS, DSC and XRPD. Results demonstrate that it was possible to follow the main cocrystallization events on-line. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Two Interlocked Triads in Pat Kinevane’s Recent Plays: Self-Soul-Conscousness and Birth-Death-Rebirth

    Directory of Open Access Journals (Sweden)

    Nicoleta Stanca

    2017-05-01

    Full Text Available Everyting conceivable, all that has ever been imagined, can be included in our minds and souls. As psyche means “breath”, “soul” and “mind”, it points to the relevance of psychology as a study of mental, emotional and spiritual processes involved in our identity make-up. One of the main organizers of our self and psychological experiences is our relationhip with death: our fear of abandonement and of being alone when conceiving our own death, the fear of the loss of the others, leading to the fear of attachment and emotional death. Pat Kinevane, a contemporary Irish playright, deals, in his 2005 play, Forgotten, with the idea of family and social abandonment of old people in nursing homes. The interconnected stories of Dora, Eucharia, Flor and Gustus, the characters in the play, aged 80-100 years old, living in separate retirement and care facilities around Ireland, reveal these fears. Mental illness in the current explosion of anxiety is also crucial to our identity. Another play by Kinevane, Silent (2010, ends with the word silent, which indicates the insanity, invisibility and ultimately the death of the protagonist, Tino McGoldring, a homeless man tormented by the suicide of his brother. His self after the loss of his brother, wife, family, job, mind is constructed in relation to the past and the imaginary world of the Italian-American icon of the film industry of the 1920s, Rudolph Valentino.

  7. Quantum Graphical Models and Belief Propagation

    International Nuclear Information System (INIS)

    Leifer, M.S.; Poulin, D.

    2008-01-01

    Belief Propagation algorithms acting on Graphical Models of classical probability distributions, such as Markov Networks, Factor Graphs and Bayesian Networks, are amongst the most powerful known methods for deriving probabilistic inferences amongst large numbers of random variables. This paper presents a generalization of these concepts and methods to the quantum case, based on the idea that quantum theory can be thought of as a noncommutative, operator-valued, generalization of classical probability theory. Some novel characterizations of quantum conditional independence are derived, and definitions of Quantum n-Bifactor Networks, Markov Networks, Factor Graphs and Bayesian Networks are proposed. The structure of Quantum Markov Networks is investigated and some partial characterization results are obtained, along the lines of the Hammersley-Clifford theorem. A Quantum Belief Propagation algorithm is presented and is shown to converge on 1-Bifactor Networks and Markov Networks when the underlying graph is a tree. The use of Quantum Belief Propagation as a heuristic algorithm in cases where it is not known to converge is discussed. Applications to decoding quantum error correcting codes and to the simulation of many-body quantum systems are described

  8. Pulsed positive corona streamer propagation and branching

    International Nuclear Information System (INIS)

    Veldhuizen, E.M. van; Rutgers, W.R.

    2002-01-01

    The propagation and branching of pulsed positive corona streamers in a short gap is observed with high resolution in space and time. The appearance of the pre-breakdown phenomena can be controlled by the electrode configuration, the gas composition and the impedance of the pulsed power circuit. In a point-wire gap the positive corona shows much more branching than in the parallel plane gap with a protrusion. In air, the branching is more pronounced than in argon. The pulsed power circuit appears to operate in two modes, either as an inductive circuit creating a lower number of thick streamers or as a resistive circuit giving a higher number of thin streamers. A possible cause for branching is electrostatic repulsion of two parts of the streamer head. The electric field at the streamer head is limited, the maximum values found are ∼170 kV cm -1 in air and ∼100 kV cm -1 in argon. At these maximum field strengths, the electrons have 5-10 eV energy, so the ionization is dominated by two-step processes. Differences between argon and ambient air in the field strength at which streamers propagate are ascribed to the difference in de-excitation processes in noble and molecular gases. The fact that the pulsed power circuit can control the streamer structure is important for applications, but this effect must also be taken into account in fundamental studies of streamer propagation and branching. (author)

  9. Pulsed positive corona streamer propagation and branching

    Energy Technology Data Exchange (ETDEWEB)

    Veldhuizen, E.M. van [Department of Physics, Technische Universiteit Eindhoven, Eindhoven (Netherlands)]. E-mail: e.m.v.veldhuizen@tue.nl; Rutgers, W.R. [Department of Physics, Technische Universiteit Eindhoven, Eindhoven (Netherlands)

    2002-09-07

    The propagation and branching of pulsed positive corona streamers in a short gap is observed with high resolution in space and time. The appearance of the pre-breakdown phenomena can be controlled by the electrode configuration, the gas composition and the impedance of the pulsed power circuit. In a point-wire gap the positive corona shows much more branching than in the parallel plane gap with a protrusion. In air, the branching is more pronounced than in argon. The pulsed power circuit appears to operate in two modes, either as an inductive circuit creating a lower number of thick streamers or as a resistive circuit giving a higher number of thin streamers. A possible cause for branching is electrostatic repulsion of two parts of the streamer head. The electric field at the streamer head is limited, the maximum values found are {approx}170 kV cm{sup -1} in air and {approx}100 kV cm{sup -1} in argon. At these maximum field strengths, the electrons have 5-10 eV energy, so the ionization is dominated by two-step processes. Differences between argon and ambient air in the field strength at which streamers propagate are ascribed to the difference in de-excitation processes in noble and molecular gases. The fact that the pulsed power circuit can control the streamer structure is important for applications, but this effect must also be taken into account in fundamental studies of streamer propagation and branching. (author)

  10. Crack propagation on spherical pressure vessels

    International Nuclear Information System (INIS)

    Lebey, J.; Roche, R.

    1975-01-01

    The risk presented by a crack on a pressure vessel built with a ductile steel cannot be well evaluated by simple application of the rules of Linear Elastic Fracture Mechanics, which only apply to brittle materials. Tests were carried out on spherical vessels of three different scales built with the same steel. Cracks of different length were machined through the vessel wall. From the results obtained, crack initiation stress (beginning of stable propagation) and instable propagation stress may be plotted against the lengths of these cracks. For small and medium size, subject to ductile fracture, the resulting curves are identical, and may be used for ductile fracture prediction. Brittle rupture was observed on larger vessels and crack propagation occurred at lower stress level. Preceedings curves are not usable for fracture analysis. Ultimate pressure can be computed with a good accuracy by using equivalent energy toughness, Ksub(1cd), characteristic of the metal plates. Satisfactory measurements have been obtained on thin samples. The risks of brittle fracture may then judged by comparing Ksub(1cd) with the calculated K 1 value, in which corrections for vessel shape are taken into account. It is thus possible to establish the bursting pressure of cracked spherical vessels, with the help of two rules, one for brittle fracture, the other for ductile instability. A practical method is proposed on the basis of the work reported here

  11. Wave propagation in nanostructures nonlocal continuum mechanics formulations

    CERN Document Server

    Gopalakrishnan, Srinivasan

    2013-01-01

    Wave Propagation in Nanostructures describes the fundamental and advanced concepts of waves propagating in structures that have dimensions of the order of nanometers. The book is fundamentally based on non-local elasticity theory, which includes scale effects in the continuum model. The book predominantly addresses wave behavior in carbon nanotubes and graphene structures, although the methods of analysis provided in this text are equally applicable to other nanostructures. The book takes the reader from the fundamentals of wave propagation in nanotubes to more advanced topics such as rotating nanotubes, coupled nanotubes, and nanotubes with magnetic field and surface effects. The first few chapters cover the basics of wave propagation, different modeling schemes for nanostructures and introduce non-local elasticity theories, which form the building blocks for understanding the material provided in later chapters. A number of interesting examples are provided to illustrate the important features of wave behav...

  12. FATIGUE CRACK PROPAGATION THROUGH AUSTEMPERED DUCTILE IRON MICROSTRUCTURE

    Directory of Open Access Journals (Sweden)

    Lukáš Bubenko

    2010-10-01

    Full Text Available Austempered ductile iron (ADI has a wide range of application, particularly for castings used in automotive and earth moving machinery industries. These components are usually subjected to variable dynamic loading that may promote initiation and propagation of fatigue cracks up to final fracture. Thus, it is important to determine the fatigue crack propagation behavior of ADI. Since fatigue crack growth rate (da/dN vs. stress intensity factor K data describe fatigue crack propagation resistance and fatigue durability of structural materials, da/dN vs. Ka curves of ADI 1050 are reported here. The threshold amplitude of stress intensity factor Kath is also determined. Finally, the influence of stress intensity factor amplitude to the character of fatigue crack propagation through the ADI microstructure is described.

  13. Hydrodynamic model of hydrogen-flame propagation in reactor vessels

    International Nuclear Information System (INIS)

    Baer, M.R.; Ratzel, A.C.

    1982-01-01

    A hydrodynamic model for hydrogen flame propagation in reactor geometries is presented. This model is consistent with the theory of slow combustion in which the gasdynamic field equations are treated in the limit of small Mach numbers. To the lowest order, pressure is spatially uniform. The flame is treated as a density and entropy discontinuity which propagates at prescribed burning velocities, corresponding to laminar or turbulent flames. Radiation cooling of the burned combustion gases and possible preheating of the unburned gases during propagation of the flame is included using a molecular gas-band thermal radiation model. Application of this model has been developed for 1-D variable area flame propagation. Multidimensional effects induced by hydrodynamics and buoyancy are introduced as a correction to the burn velocity (which reflects a modification of planar flame surface to a distorted surface) using experimentally measured pressure-rise time data for hydrogen/air deflagrations in cylindrical vessels

  14. The utilization of induction generators working with PATs (pumps working as turbines) in electric energy generation; A utilizacao de geradores de inducao acionados por BFTs (bombas funcionando como turbinas) na geracao de energia eletrica

    Energy Technology Data Exchange (ETDEWEB)

    Viana, Augusto Nelson Carvalho; Rezek, Angelo Jose Junqueira; Medeiros, Daniel de Macedo [Universidade Federal de Itajuba (UNIFEI), MG (Brazil). Programa de Pos-graduacao em Engenharia da Energia], e-mail: augusto@unifei.edu.br, e-mail: rezek@iee.efei.br, e-mail: macedo@unifei.edu.br

    2004-07-01

    The utilization of the Pumps working as Turbines (PATs) in micro hydro-energy resources to replace the conventional turbines as Pelton, Francis and Propeller have been used in countries as USA, Germany and France. In the mean time, in Brazil this practice and the utilization of induction generators working with PATs is still in the scope of the laboratory experiments. This work, based on experimental results carried on in Laboratory of Hydromechanics for Small Hydro Power Plants (Laboratorio Hidromecanico para Pequenas Centrais Hidroeletricas - LHPCH - UNIFEI), (VIANA, 1987), (VIANA e NOGUEIRA, 1990), propose the utilization of asynchronous generator groups operating with PATs. To show the investment cost decrease in micro hydro power plants (MHPs), is showed the Boa Esperanca MPH example, in which is presented a comparison between the synchronous generator group cost working with a Michell-Banki turbine and a asynchronous generator group operating with a PAT. (author)

  15. Laser beam propagation through random media

    CERN Document Server

    Andrews, Larry C

    2005-01-01

    Since publication of the first edition of this text in 1998, there have been several new, important developments in the theory of beam wave propagation through a random medium, which have been incorporated into this second edition. Also new to this edition are models for the scintillation index under moderate-to-strong irradiance fluctuations; models for aperture averaging based on ABCD ray matrices; beam wander and its effects on scintillation; theory of partial coherence of the source; models of rough targets for ladar applications; phase fluctuations; analysis of other beam shapes; plus exp

  16. Group symmetries and information propagation

    International Nuclear Information System (INIS)

    Draayer, J.P.

    1980-01-01

    Spectroscopy concerns itself with the ways in which the Hamiltonian and other interesting operators defined in few-particle spaces are determined or determine properties of many-particle systems. But the action of the central limit theorem (CLT) filters the transmission of information between source and observed so whether propagating forward from a few-particle defining space, as is usual in theoretical studies, or projecting backward to it from measured things, each is only sensitive to averaged properties of the other. Our concern is with the propagation of spectroscopic information in the presence of good symmetries when filtering action of the CLT is effective. Specifically, we propose to address the question, What propagates and how. We begin with some examples, using both scalar and isospin geometries to illustrate simple propagation. Examples of matrix propagation are studied; contact with standard tensor algebra is established and an algorithm put forward for the expansion of any operator in terms of another set, complete or not; shell-model results for 20 Ne using a realistic interaction and two trace-equivalent forms are presented; and some further challenges are mentioned

  17. Propagation of an ultra intense laser pulse in an under dense plasma: production of quasi monoenergetic electron beams and development of applications; Propagation d'une impulsion laser ultra-intense dans un plasma sous-dense: generation de faisceaux d'electrons quasi monoenergetiques et developpement d'applications

    Energy Technology Data Exchange (ETDEWEB)

    Glinec, Y

    2006-09-15

    This experimental study concerns the generation of electron beams with original properties. These electrons beams originate from the interaction of an ultra-intense and short laser pulse with a gas jet. Previously, these electron beams had a large divergence and a broad spectrum. A major improvement in this field was achieved when an electron beam with low divergence (10 mrad) and a peaked spectrum (170 MeV) was observed during this thesis, using a new single shot electron spectrometer. A parametric study of the interaction allowed to observe the evolution of the electron beam. Experiments have been carried out to deepen the characterization of the electron beam. The observation of transition radiation generated by the electrons at an interface shows that the electron beam interacts with the laser pulse during the acceleration. Radial oscillations of the electron beam around the laser axis, named betatron oscillations, were also observed on the electron spectra. Such a quasi-monoenergetic spectrum is essential for many applications. In order to justify the interest of this electron beam, several applications are presented: a sub-milli-metric gamma-ray radiography of dense objects, a dose profile of the electron beam comparable to present capabilities of photon sources for radiotherapy, a very short temporal profile useful for water radiolysis and the generation of a bright X-ray source with low divergence. (author)

  18. Propagation of an ultra intense laser pulse in an under dense plasma: production of quasi monoenergetic electron beams and development of applications; Propagation d'une impulsion laser ultra-intense dans un plasma sous-dense: generation de faisceaux d'electrons quasi monoenergetiques et developpement d'applications

    Energy Technology Data Exchange (ETDEWEB)

    Glinec, Y

    2006-09-15

    This experimental study concerns the generation of electron beams with original properties. These electrons beams originate from the interaction of an ultra-intense and short laser pulse with a gas jet. Previously, these electron beams had a large divergence and a broad spectrum. A major improvement in this field was achieved when an electron beam with low divergence (10 mrad) and a peaked spectrum (170 MeV) was observed during this thesis, using a new single shot electron spectrometer. A parametric study of the interaction allowed to observe the evolution of the electron beam. Experiments have been carried out to deepen the characterization of the electron beam. The observation of transition radiation generated by the electrons at an interface shows that the electron beam interacts with the laser pulse during the acceleration. Radial oscillations of the electron beam around the laser axis, named betatron oscillations, were also observed on the electron spectra. Such a quasi-monoenergetic spectrum is essential for many applications. In order to justify the interest of this electron beam, several applications are presented: a sub-milli-metric gamma-ray radiography of dense objects, a dose profile of the electron beam comparable to present capabilities of photon sources for radiotherapy, a very short temporal profile useful for water radiolysis and the generation of a bright X-ray source with low divergence. (author)

  19. Genética de la resistencia de la papa (Solanum tuberosum a patógenos. Estado de arte

    Directory of Open Access Journals (Sweden)

    Mosquera Teresa

    2008-04-01

    Full Text Available

    Este artículo presenta una revisión de la resistencia en papa a patógenos, en cuanto a genes mapeados y clonados, y loci de rasgos cuantitativos (QTL mapeados, en la que se resaltan las relaciones entre resistencia cuantitativa y cualitativa en el caso P. infestans. El conocimiento logrado ha permitido generar un mapa funcional sobre el cual se localizan QTL para resistencia a patógenos. Se han mapeado 20 genes R de resistencia a virus, hongos, nematodos y oomicetos, utilizando marcadores moleculares. La mayoría de estos genes R fueron introducidos de especies silvestres. Catorce de ellos se encuentran en hot spots para resistencia y confieren resistencia a varios patógenos. A la fecha se han identificado cinco clusters de resistencia. La resistencia monogénica envuelve dos procesos básicos: percepción del ataque del patógeno, seguida de una respuesta para limitar la enfermedad. La percepción implica receptores específicos para cepas patogénicas, que son decodificadas por genes de resistencia. En una planta se encuentra un gran repertorio de genes de resistencia R, ubicados en diferentes sitios del genoma. Estos genes expresan diferentes proteínas que pueden ser agrupadas en varias familias. La mayoría de proteínas R contienen repeticiones en grupos, ricas en leucina (LRR. Se plantea la colocalización de genes R y QTL en diferentes cromosomas. Una hipótesis señala que los QTL son variantes alélicas con efecto menos extremo que los genes R y una segunda hipótesis plantea que los QTL de resistencia mapean en regiones del genoma que contienen genes de función conocida involucrados en la respuesta general al ataque de patógenos.

  20. High Throughput Multispectral Image Processing with Applications in Food Science.

    Directory of Open Access Journals (Sweden)

    Panagiotis Tsakanikas

    Full Text Available Recently, machine vision is gaining attention in food science as well as in food industry concerning food quality assessment and monitoring. Into the framework of implementation of Process Analytical Technology (PAT in the food industry, image processing can be used not only in estimation and even prediction of food quality but also in detection of adulteration. Towards these applications on food science, we present here a novel methodology for automated image analysis of several kinds of food products e.g. meat, vanilla crème and table olives, so as to increase objectivity, data reproducibility, low cost information extraction and faster quality assessment, without human intervention. Image processing's outcome will be propagated to the downstream analysis. The developed multispectral image processing method is based on unsupervised machine learning approach (Gaussian Mixture Models and a novel unsupervised scheme of spectral band selection for segmentation process optimization. Through the evaluation we prove its efficiency and robustness against the currently available semi-manual software, showing that the developed method is a high throughput approach appropriate for massive data extraction from food samples.

  1. High Throughput Multispectral Image Processing with Applications in Food Science.

    Science.gov (United States)

    Tsakanikas, Panagiotis; Pavlidis, Dimitris; Nychas, George-John

    2015-01-01

    Recently, machine vision is gaining attention in food science as well as in food industry concerning food quality assessment and monitoring. Into the framework of implementation of Process Analytical Technology (PAT) in the food industry, image processing can be used not only in estimation and even prediction of food quality but also in detection of adulteration. Towards these applications on food science, we present here a novel methodology for automated image analysis of several kinds of food products e.g. meat, vanilla crème and table olives, so as to increase objectivity, data reproducibility, low cost information extraction and faster quality assessment, without human intervention. Image processing's outcome will be propagated to the downstream analysis. The developed multispectral image processing method is based on unsupervised machine learning approach (Gaussian Mixture Models) and a novel unsupervised scheme of spectral band selection for segmentation process optimization. Through the evaluation we prove its efficiency and robustness against the currently available semi-manual software, showing that the developed method is a high throughput approach appropriate for massive data extraction from food samples.

  2. Signal propagation along the axon.

    Science.gov (United States)

    Rama, Sylvain; Zbili, Mickaël; Debanne, Dominique

    2018-03-08

    Axons link distant brain regions and are usually considered as simple transmission cables in which reliable propagation occurs once an action potential has been generated. Safe propagation of action potentials relies on specific ion channel expression at strategic points of the axon such as nodes of Ranvier or axonal branch points. However, while action potentials are generally considered as the quantum of neuronal information, their signaling is not entirely digital. In fact, both their shape and their conduction speed have been shown to be modulated by activity, leading to regulations of synaptic latency and synaptic strength. We report here newly identified mechanisms of (1) safe spike propagation along the axon, (2) compartmentalization of action potential shape in the axon, (3) analog modulation of spike-evoked synaptic transmission and (4) alteration in conduction time after persistent regulation of axon morphology in central neurons. We discuss the contribution of these regulations in information processing. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Ação de herbicidas sobre mecanismos de defesa das plantas aos patógenos

    Directory of Open Access Journals (Sweden)

    Rizzardi Mauro Antônio

    2003-01-01

    Full Text Available As plantas necessitam defender-se continuamente do ataque de agentes biológicos e de estresses do ambiente. A imobilidade e a falta de sistema imunológico, como ocorre em animais, fizeram com que as plantas desenvolvessem mecanismos de defesa, em que cada célula possui tanto capacidade de defesa induzida quanto pré-formada. No entanto, esses mecanismos podem ser influenciados pelo uso de herbicidas. A presente revisão objetivou apresentar os efeitos de herbicidas em mecanismos de defesa das plantas contra patógenos, bem como analisar as possíveis conseqüências desse conhecimento no manejo de plantas daninhas e de culturas. Alguns herbicidas influenciam a severidade de doenças, induzindo ou inibindo a síntese de fitoalexinas. Herbicidas do grupo químico difeniléteres geram espécies reativas de oxigênio, as quais mediam a ativação de genes de defesa responsáveis pela síntese de fitoalexinas e também por reação de hipersensibilidade. O uso de subdoses de glyphosate ocasiona efeito contrário, diminuindo a produção de fitoalexinas e aumentando a severidade de doenças. A constatação desses efeitos requer a adoção de estratégias de manejo que minimizem seus impactos negativos ou que se beneficiem desses efeitos, como pode ocorrer quando do uso de bioherbicidas.

  4. Simulation of sound waves using the Lattice Boltzmann Method for fluid flow: Benchmark cases for outdoor sound propagation

    NARCIS (Netherlands)

    Salomons, E.M.; Lohman, W.J.A.; Zhou, H.

    2016-01-01

    Propagation of sound waves in air can be considered as a special case of fluid dynamics. Consequently, the lattice Boltzmann method (LBM) for fluid flow can be used for simulating sound propagation. In this article application of the LBM to sound propagation is illustrated for various cases:

  5. Wave equations for pulse propagation

    International Nuclear Information System (INIS)

    Shore, B.W.

    1987-01-01

    Theoretical discussions of the propagation of pulses of laser radiation through atomic or molecular vapor rely on a number of traditional approximations for idealizing the radiation and the molecules, and for quantifying their mutual interaction by various equations of propagation (for the radiation) and excitation (for the molecules). In treating short-pulse phenomena it is essential to consider coherent excitation phenomena of the sort that is manifest in Rabi oscillations of atomic or molecular populations. Such processes are not adequately treated by rate equations for excitation nor by rate equations for radiation. As part of a more comprehensive treatment of the coupled equations that describe propagation of short pulses, this memo presents background discussion of the equations that describe the field. This memo discusses the origin, in Maxwell's equations, of the wave equation used in the description of pulse propagation. It notes the separation into lamellar and solenoidal (or longitudinal and transverse) and positive and negative frequency parts. It mentions the possibility of separating the polarization field into linear and nonlinear parts, in order to define a susceptibility or index of refraction and, from these, a phase and group velocity. The memo discusses various ways of characterizing the polarization characteristics of plane waves, that is, of parameterizing a transverse unit vector, such as the Jones vector, the Stokes vector, and the Poincare sphere. It discusses the connection between macroscopically defined quantities, such as the intensity or, more generally, the Stokes parameters, and microscopic field amplitudes. The material presented here is a portion of a more extensive treatment of propagation to be presented separately. The equations presented here have been described in various books and articles. They are collected here as a summary and review of theory needed when treating pulse propagation

  6. Vegetative propagation of Bambusa vulgaris

    Directory of Open Access Journals (Sweden)

    Rafael Malfitano Braga

    2017-06-01

    Full Text Available Bamboo is an important source of raw material of multiple uses. The development of simple techniques for its propagation is a practical way to enable its implementation in ownership of low technology. The present work had the objective of evaluating artisanal propagation methods for Bambusa vulgaris. Two types of propagules were tested, with buds budded or not, and three relative positions to the removal of vegetative material on the culm. The best propagule was with only one node, extracted from the lower thirds of the stem, presenting 72% of rooting. This result demonstrates its potential for seedling production of this species under low tech.

  7. Nonequilibrium theory of flame propagation

    International Nuclear Information System (INIS)

    Merzhanov, A.G.

    1995-01-01

    The nonequilibrium theory of flame propagation is considered as applied to the following three processes of wave propagation: the combustion waves of the second kind, the combustion waves with broad reaction zones, and the combustion waves with chemical stages. Kinetic and combustion wave parameters are presented for different in composition mixtures of boron and transition metals, such as Zr, Hf, Ti, Nb, Ta, Mo, as well as for the Ta-N, Zr-C-H, Nb-B-O systems to illustrate specific features of the above-mentioned processes [ru

  8. Neutrino propagation in a fluctuating sun

    International Nuclear Information System (INIS)

    Burgess, C.P.; Michaud, D.

    1997-01-01

    We adapt to neutrino physics a general formulation for particle propagation in fluctuating media, initially developed for applications to electromagnetism and neutron optics. In leading approximation this formalism leads to the usual MSW effective Hamiltonian governing neutrino propagation through a medium. Next-to-leading contributions describe deviations from this description, which arise due to neutrino interactions with fluctuations in the medium. We compute these corrections for two types of fluctuations: (i) microscopic thermal fluctuations and (ii) macroscopic fluctuations in the medium s density. While the first of these reproduces standard estimates, which are negligible for applications to solar neutrinos, we find that the second can be quite large, since it grows in size with the correlation length of the fluctuation. We consider two models in some detail. For fluctuations whose correlations extend only over a local region in space of length l, appreciable effects for MSW oscillations arise if (δn/n) 2 l approx-gt 100m or so. Alternatively, a crude model of helioseismic p-waves gives appreciable effects only when (δn/n)approx-gt 1%. In general the dominant effect is to diminish the quality of the resonance, making the suppression of the 7 Be neutrinos a good experimental probe of fluctuations deep within the sun. Fluctuations can also provide a new mechanism for reducing the solar neutrino flux, giving an energy-independent suppression factor of 1/2 away from the resonant region, even for small vacuum mixing angles. copyright 1997 Academic Press, Inc

  9. Morse oscillator propagator in the high temperature limit II: Quantum dynamics and spectroscopy

    Science.gov (United States)

    Toutounji, Mohamad

    2018-04-01

    This paper is a continuation of Paper I (Toutounji, 2017) of which motivation was testing the applicability of Morse oscillator propagator whose analytical form was derived by Duru (1983). This is because the Morse oscillator propagator was reported (Duru, 1983) in a triple-integral form of a functional of modified Bessel function of the first kind, which considerably limits its applicability. For this reason, I was prompted to find a regime under which Morse oscillator propagator may be simplified and hence be expressed in a closed-form. This was well accomplished in Paper I. Because Morse oscillator is of central importance and widely used in modelling vibrations, its propagator applicability will be extended to applications in quantum dynamics and spectroscopy as will be reported in this paper using the off-diagonal propagator of Morse oscillator whose analytical form is derived.

  10. Propagation and wavefront ambiguity of linear nondiffracting beams

    Science.gov (United States)

    Grunwald, R.; Bock, M.

    2014-02-01

    Ultrashort-pulsed Bessel and Airy beams in free space are often interpreted as "linear light bullets". Usually, interconnected intensity profiles are considered a "propagation" along arbitrary pathways which can even follow curved trajectories. A more detailed analysis, however, shows that this picture gives an adequate description only in situations which do not require to consider the transport of optical signals or causality. To also cover these special cases, a generalization of the terms "beam" and "propagation" is necessary. The problem becomes clearer by representing the angular spectra of the propagating wave fields by rays or Poynting vectors. It is known that quasi-nondiffracting beams can be described as caustics of ray bundles. Their decomposition into Poynting vectors by Shack-Hartmann sensors indicates that, in the frame of their classical definition, the corresponding local wavefronts are ambiguous and concepts based on energy density are not appropriate to describe the propagation completely. For this reason, quantitative parameters like the beam propagation factor have to be treated with caution as well. For applications like communication or optical computing, alternative descriptions are required. A heuristic approach based on vector field based information transport and Fourier analysis is proposed here. Continuity and discontinuity of far field distributions in space and time are discussed. Quantum aspects of propagation are briefly addressed.

  11. Pressure wave propagation in the discharge piping with water pool

    International Nuclear Information System (INIS)

    Bang, Young S.; Seul, Kwang W.; Kim, In Goo

    2004-01-01

    Pressure wave propagation in the discharge piping with a sparger submerged in a water pool, following the opening of a safety relief valve, is analyzed. To predict the pressure transient behavior, a RELAP5/MOD3 code is used. The applicability of the RELAP5 code and the adequacy of the present modeling scheme are confirmed by simulating the applicable experiment on a water hammer with voiding. As a base case, the modeling scheme was used to calculate the wave propagation inside a vertical pipe with sparger holes and submerged within a water pool. In addition, the effects on wave propagation of geometric factors, such as the loss coefficient, the pipe configuration, and the subdivision of sparger pipe, are investigated. The effects of inflow conditions, such as water slug inflow and the slow opening of a safety relief valve are also examined

  12. Propagation modeling in a manufacturing environment

    Energy Technology Data Exchange (ETDEWEB)

    Birdwell, J.D.; Horn, R.D.; Rader, M.S. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Electrical Engineering; Shourbaji, A.A. [Oak Ridge Centers for Mfg. Technology, TN (United States)

    1995-12-31

    Wireless sensors which utilize low power spread spectrum data transmission have significant potential in industrial environments due to low cabling and installation costs. In addition, this technology imposes fewer constraints upon placement due to cable routing, allowing sensors to be installed in areas with poor access. Limitations are imposed on sensor and receiver placement by electromagnetic propagation effects in the industrial environment, including multipath and the presence of absorbing media. This paper explores the electromagnetic analysis of potential wireless sensor applications using commercially available finite element software. In addition, since the applications environment is often at least partially specified in electronic form using computer-aided drafting software, the importation of information from this software is discussed. Both three-dimensional and two-dimensional examples are presented which demonstrate the utility and limitations of the method.

  13. Physics of Earthquake Rupture Propagation

    Science.gov (United States)

    Xu, Shiqing; Fukuyama, Eiichi; Sagy, Amir; Doan, Mai-Linh

    2018-05-01

    A comprehensive understanding of earthquake rupture propagation requires the study of not only the sudden release of elastic strain energy during co-seismic slip, but also of other processes that operate at a variety of spatiotemporal scales. For example, the accumulation of the elastic strain energy usually takes decades to hundreds of years, and rupture propagation and termination modify the bulk properties of the surrounding medium that can influence the behavior of future earthquakes. To share recent findings in the multiscale investigation of earthquake rupture propagation, we held a session entitled "Physics of Earthquake Rupture Propagation" during the 2016 American Geophysical Union (AGU) Fall Meeting in San Francisco. The session included 46 poster and 32 oral presentations, reporting observations of natural earthquakes, numerical and experimental simulations of earthquake ruptures, and studies of earthquake fault friction. These presentations and discussions during and after the session suggested a need to document more formally the research findings, particularly new observations and views different from conventional ones, complexities in fault zone properties and loading conditions, the diversity of fault slip modes and their interactions, the evaluation of observational and model uncertainties, and comparison between empirical and physics-based models. Therefore, we organize this Special Issue (SI) of Tectonophysics under the same title as our AGU session, hoping to inspire future investigations. Eighteen articles (marked with "this issue") are included in this SI and grouped into the following six categories.

  14. Invisibility cloaking without superluminal propagation

    Energy Technology Data Exchange (ETDEWEB)

    Perczel, Janos; Leonhardt, Ulf [School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews KY16 9SS (United Kingdom); Tyc, Tomas, E-mail: jp394@st-andrews.ac.uk, E-mail: tomtyc@physics.muni.cz, E-mail: ulf@st-andrews.ac.uk [Faculty of Science, Kotlarska 2 and Faculty of Informatics, Botanicka 68a, Masaryk University, 61137 Brno (Czech Republic)

    2011-08-15

    Conventional cloaking based on Euclidean transformation optics requires that the speed of light should tend to infinity on the inner surface of the cloak. Non-Euclidean cloaking still needs media with superluminal propagation. Here we show by giving an example that this is no longer necessary.

  15. Propagating Class and Method Combination

    DEFF Research Database (Denmark)

    Ernst, Erik

    1999-01-01

    number of implicit combinations. For example, it is possible to specify separate aspects of a family of classes, and then combine several aspects into a full-fledged class family. The combination expressions would explicitly combine whole-family aspects, and by propagation implicitly combine the aspects...

  16. Interactive Sound Propagation using Precomputation and Statistical Approximations

    Science.gov (United States)

    Antani, Lakulish

    Acoustic phenomena such as early reflections, diffraction, and reverberation have been shown to improve the user experience in interactive virtual environments and video games. These effects arise due to repeated interactions between sound waves and objects in the environment. In interactive applications, these effects must be simulated within a prescribed time budget. We present two complementary approaches for computing such acoustic effects in real time, with plausible variation in the sound field throughout the scene. The first approach, Precomputed Acoustic Radiance Transfer, precomputes a matrix that accounts for multiple acoustic interactions between all scene objects. The matrix is used at run time to provide sound propagation effects that vary smoothly as sources and listeners move. The second approach couples two techniques---Ambient Reverberance, and Aural Proxies---to provide approximate sound propagation effects in real time, based on only the portion of the environment immediately visible to the listener. These approaches lie at different ends of a space of interactive sound propagation techniques for modeling sound propagation effects in interactive applications. The first approach emphasizes accuracy by modeling acoustic interactions between all parts of the scene; the second approach emphasizes efficiency by only taking the local environment of the listener into account. These methods have been used to efficiently generate acoustic walkthroughs of architectural models. They have also been integrated into a modern game engine, and can enable realistic, interactive sound propagation on commodity desktop PCs.

  17. Maximum nondiffracting propagation distance of aperture-truncated Airy beams

    Science.gov (United States)

    Chu, Xingchun; Zhao, Shanghong; Fang, Yingwu

    2018-05-01

    Airy beams have called attention of many researchers due to their non-diffracting, self-healing and transverse accelerating properties. A key issue in research of Airy beams and its applications is how to evaluate their nondiffracting propagation distance. In this paper, the critical transverse extent of physically realizable Airy beams is analyzed under the local spatial frequency methodology. The maximum nondiffracting propagation distance of aperture-truncated Airy beams is formulated and analyzed based on their local spatial frequency. The validity of the formula is verified by comparing the maximum nondiffracting propagation distance of an aperture-truncated ideal Airy beam, aperture-truncated exponentially decaying Airy beam and exponentially decaying Airy beam. Results show that the formula can be used to evaluate accurately the maximum nondiffracting propagation distance of an aperture-truncated ideal Airy beam. Therefore, it can guide us to select appropriate parameters to generate Airy beams with long nondiffracting propagation distance that have potential application in the fields of laser weapons or optical communications.

  18. Drone-borne GPR design: Propagation issues

    Science.gov (United States)

    Chandra, Madhu; Tanzi, Tullio Joseph

    2018-01-01

    In this paper, we shall address the electromagnetic wave propagation issues that are critical to determining the feasibility of a drone-borne ground-penetrating radar sensor for humanitarian applications, particularly in the context of disaster management. Frequency- and polarization-dependent scattering, attenuation and dispersion of radar signals penetrating into the sub-surface region will determine the applicability of a drone-mounted radar sensor capable of registering radar echoes for observing and monitoring sub-surface features. The functionality of the radar will thus be assessed depending on key radar parameters that include the central radar frequency, the modulation depth, and the mode of radar operation (pulsed FM, FM-CW), the antenna type, the available power-budget. In the analysis to be presented, the radar equation, together with the aforementioned propagation effects, will be used to simulate the signal strength of radar echoes under different conditions arising from the chosen key-radar parameters and the assumed physical properties of the sub-surface earth medium. The analysis to be presented will indicate whether or not the drone-borne ground-penetrating radar is a feasible system and if it could be constructed with the technologies available today. Taking into account the strict constraints involved to design drone applications for Public Protection and Disaster Relief (PPDR), the ideas developed hereafter are both prospective and exploratory. The objective is to see if a solution can be found in the near future. xml:lang="fr" Dans l'analyse présentée, l'équation radar, ainsi que les effets de propagation susmentionnés, serviront à simuler la puissance du signal des échos radar sous différentes conditions découlant des paramètres clés choisis et les propriétés physiques du milieu sous la surface. L'étude a pour objectif de démontrer si le système est réalisable et s'il peut être construit avec les technologies disponibles

  19. 50 CFR 21.30 - Raptor propagation permits.

    Science.gov (United States)

    2010-10-01

    ... (CONTINUED) TAKING, POSSESSION, TRANSPORTATION, SALE, PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF... take, possess, transport, import, purchase, barter, or offer to sell, purchase, or barter any raptor... of the applicant's experience with raptor propagation or handling raptors; (4) A description of each...

  20. Propagation of waves in a multicomponent plasma having charged ...

    Indian Academy of Sciences (India)

    Propagation of waves in a multicomponent plasma having charged dust particles has been investigated by various authors in recent times as the presence of charged dust grains give rise to a new kind of modes called dust modes and it has wide applications in magneto- sphere and space plasma [1–3]. In fact, Rao et al [4] ...

  1. Propagation of field disturbances in Yang-Mills theory

    International Nuclear Information System (INIS)

    De Lorenci, Vitorio A.; Li Shiyuan

    2008-01-01

    The propagation of field disturbances is examined in the context of the effective Yang-Mills Lagrangian, which is intended to be applied to QCD systems. It is shown that birefringence phenomena can occur in such systems provided some restrictive conditions, as causality, are fulfilled. Possible applications to phenomenology are addressed.

  2. PIV tracer behavior on propagating shock fronts

    International Nuclear Information System (INIS)

    Glazyrin, Fyodor N; Mursenkova, Irina V; Znamenskaya, Irina A

    2016-01-01

    The present work was aimed at the quantitative particle image velocimetry (PIV) measurement of a velocity field near the front of a propagating shock wave and the study of the dynamics of liquid tracers crossing the shock front. For this goal, a shock tube with a rectangular cross-section (48  ×  24 mm) was used. The flat shock wave with Mach numbers M  =  1.4–2.0 propagating inside the tube channel was studied as well as an expanding shock wave propagating outside the channel with M  =  1.2–1.8 at its main axis. The PIV imaging of the shock fronts was carried out with an aerosol of dioctyl sebacate (DEHS) as tracer particles. The pressures of the gas in front of the shock waves studied ranged from 0.013 Mpa to 0.1 MPa in the series of experiments. The processed PIV data, compared to the 1D normal shock theory, yielded consistent values of wake velocity immediately behind the plain shock wave. Special attention was paid to the blurring of the velocity jump on the shock front due to the inertial particle lag and peculiarities of the PIV technique. A numerical algorithm was developed for analysis and correction of the PIV data on the shock fronts, based on equations of particle-flow interaction. By application of this algorithm, the effective particle diameter of the DEHS aerosol tracers was estimated as 1.03  ±  0.12 μm. A number of different formulations for particle drag were tested with this algorithm, with varying success. The results show consistency with previously reported experimental data obtained for cases of stationary shock waves. (paper)

  3. Numerical Algorithms for Precise and Efficient Orbit Propagation and Positioning

    Science.gov (United States)

    Bradley, Ben K.

    Motivated by the growing space catalog and the demands for precise orbit determination with shorter latency for science and reconnaissance missions, this research improves the computational performance of orbit propagation through more efficient and precise numerical integration and frame transformation implementations. Propagation of satellite orbits is required for astrodynamics applications including mission design, orbit determination in support of operations and payload data analysis, and conjunction assessment. Each of these applications has somewhat different requirements in terms of accuracy, precision, latency, and computational load. This dissertation develops procedures to achieve various levels of accuracy while minimizing computational cost for diverse orbit determination applications. This is done by addressing two aspects of orbit determination: (1) numerical integration used for orbit propagation and (2) precise frame transformations necessary for force model evaluation and station coordinate rotations. This dissertation describes a recently developed method for numerical integration, dubbed Bandlimited Collocation Implicit Runge-Kutta (BLC-IRK), and compare its efficiency in propagating orbits to existing techniques commonly used in astrodynamics. The BLC-IRK scheme uses generalized Gaussian quadratures for bandlimited functions. It requires significantly fewer force function evaluations than explicit Runge-Kutta schemes and approaches the efficiency of the 8th-order Gauss-Jackson multistep method. Converting between the Geocentric Celestial Reference System (GCRS) and International Terrestrial Reference System (ITRS) is necessary for many applications in astrodynamics, such as orbit propagation, orbit determination, and analyzing geoscience data from satellite missions. This dissertation provides simplifications to the Celestial Intermediate Origin (CIO) transformation scheme and Earth orientation parameter (EOP) storage for use in positioning and

  4. On-line near infrared spectroscopy as a Process Analytical Technology (PAT) tool to control an industrial seeded API crystallization.

    Science.gov (United States)

    Schaefer, C; Lecomte, C; Clicq, D; Merschaert, A; Norrant, E; Fotiadu, F

    2013-09-01

    The final step of an active pharmaceutical ingredient (API) manufacturing synthesis process consists of a crystallization during which the API and residual solvent contents have to be quantified precisely in order to reach a predefined seeding point. A feasibility study was conducted to demonstrate the suitability of on-line NIR spectroscopy to control this step in line with new version of the European Medicines Agency (EMA) guideline [1]. A quantitative method was developed at laboratory scale using statistical design of experiments (DOE) and multivariate data analysis such as principal component analysis (PCA) and partial least squares (PLS) regression. NIR models were built to quantify the API in the range of 9-12% (w/w) and to quantify the residual methanol in the range of 0-3% (w/w). To improve the predictive ability of the models, the development procedure encompassed: outliers elimination, optimum model rank definition, spectral range and spectral pre-treatment selection. Conventional criteria such as, number of PLS factors, R(2), root mean square errors of calibration, cross-validation and prediction (RMSEC, RMSECV, RMSEP) enabled the selection of three model candidates. These models were tested in the industrial pilot plant during three technical campaigns. Results of the most suitable models were evaluated against to the chromatographic reference methods. Maximum relative bias of 2.88% was obtained about API target content. Absolute bias of 0.01 and 0.02% (w/w) respectively were achieved at methanol content levels of 0.10 and 0.13% (w/w). The repeatability was assessed as sufficient for the on-line monitoring of the 2 analytes. The present feasibility study confirmed the possibility to use on-line NIR spectroscopy as a PAT tool to monitor in real-time both the API and the residual methanol contents, in order to control the seeding of an API crystallization at industrial scale. Furthermore, the successful scale-up of the method proved its capability to be

  5. Gérmenes patógenos aislados en niños con infecciones respiratorias a repetición

    Directory of Open Access Journals (Sweden)

    Yoenny Peña García

    2015-01-01

    Full Text Available Las infecciones respiratorias agudas son la causa más frecuente de morbilidad y de elevada mortalidad en el mundo, particularmente en los países en desarrollo. Se realizó un estudio descriptivo de corte transversal, para caracterizar a los niños con infecciones respiratorias a repetición, según los gérmenes patógenos aislados, en el círculo infantil “Flores de la Vida” del municipio de Puerto Padre, en el período de abril a mayo de 2014. Se trabajó con los niños de los salones de segundo, tercero y cuarto año de vida, distribuidos según edad y sexo, a los que se les identificaron los gérmenes patógenos aislados en exudados nasofaríngeos. La información se obtuvo del departamento de microbiología del Centro Municipal de Higiene y Epidemiología. Se obtuvieron los siguientes resultados: el grupo de edad más frecuente fue el de dos años, que representó el 45 % de la muestra y se correspondió con la media de la edad. El 62,5 % de la muestra de estudio correspondió al sexo masculino. Los gérmenes patógenos aislados con mayor frecuencia fueron: el Streptococcus pneumoneae, para un 83,9 %, el Streptococcus B hemolítico, para un 7,1 % y el Haemophillus inflienzae para un 5,4 %

  6. Estudio comparativo entre aislados clínicos y no clínicos de S. cerevisiae y su papel como patógeno emergente.

    OpenAIRE

    Llanos Frutos, Rosa de

    2007-01-01

    RESUMEN La levadura Saccharomyces cerevisiae es la especie más utilizada desde un punto de vista biotecnológico. En la industria agroalimentaria interviene en la elaboración de pan y bebidas alcohólicas como el vino y la cerveza, además se emplea como suplemento dietético y como agente probiótico bajo el nombre de S. cerevisiae var. boulardii. A pesar de sus propiedades beneficiosas, S. cerevisiae se considera actualmente una levadura patógena oportunista emergente de baja virulencia, capa...

  7. Etnicidad, actores y territorio : luchas de los afrodescendientes de Patía y el Valle del Chota por el acceso a tierra y agua, 1990-2010

    OpenAIRE

    Angulo Balanta, Diana Patricia

    2013-01-01

    Esta investigación trata de entender, desde el paradigma de la identidad, las transformaciones en los procesos organizativos y construcción identitarias de las poblaciones afrodescendientes del Patía y El Valle del Chota. Este análisis aborda la incursión de este grupo social en el campo político, para establecer ante el Estado y la sociedad reivindicaciones de carácter redistributivo y de reconocimiento, a partir de la construcción de significados. Lo anterior implica determinar los factores...

  8. El colapso ambiental en el río Patía, Colombia: variaciones morfológicas y alteraciones en los ecosistemas de manglar

    Directory of Open Access Journals (Sweden)

    Adriana S Parra

    2014-03-01

    Full Text Available El delta del Patía ha experimentado grandes variaciones morfológicas en las últimas cuatro décadas debido a presiones antrópicas. El transvase del río Patía al río Sanquianga, debido a la construcción del canal Naranjo en 1973, y la posterior formación del brazo Patianga, han derivado en complejas problemáticas ambientales que se evidencian en la reactivación del lóbulo norte del delta y el abandono de la anterior desembocadura en el lóbulo sur. En este artículo se analizan las principales alteraciones que se presentan en el delta del Patía como producto del desvío del río y las consecuentes variaciones en el aporte fluvial y de sedimentos. Estas alteraciones se reflejan en: (1 cambios drásticos en la línea de costa, con tasas de erosión de hasta 70 m año-1; (2 dulcificación de los estuarios del lóbulo norte del delta, cambio hidrológico que ha ocasionando la migración de la zona alta estuarina (salinidad <1 15 km aguas abajo; y (3 alteraciones en la cobertura vegetal del Parque Nacional Natural Sanquianga, con incrementos en la vegetación de agua dulce de hasta 42%, y disminución en la cobertura de manglar de hasta 31% en un período de 15 años. Las condiciones actuales del delta del Patía son ejemplo de la importancia de las actividades humanas como agentes de cambio dentro de la evolución de los sistemas deltaicos, y revelan la necesidad de profundizar el estudio de este delta para establecer estrategias adecuadas de manejo y conservación.

  9. Alternativas tecnológicas aplicables al desarrollo y conservación de productos cárnicos cocidos (patés) durante el almacenamiento refrigerado

    OpenAIRE

    Terrasa, Ana María

    2012-01-01

    Teniendo en cuenta la relación existente entre nutrición y salud así como la demanda creciente de los consumidores de productos más saludables, en este trabajo de Tesis se han diseñado productos a base de hígado de pollo (patés o pastas de hígado) en los cuales se realizaron modificaciones de la fase grasa tanto cualitativas como cuantitativas. En ese sentido, en productos procesados elaborados con carne o vísceras, una de las estrategias utilizadas para la obtención de productos más saludabl...

  10. Técnicas moleculares para la detección e identificación de patógenos en alimentos: ventajas y limitaciones

    Directory of Open Access Journals (Sweden)

    Carolina Palomino-Camargo

    2014-09-01

    Full Text Available Las enfermedades transmitidas por alimentos, ocasionadas por microorganismos patógenos, constituyen un grave problema de salud pública a nivel mundial. Los métodos microbiológicos utilizados comúnmente en la detección de estos patógenos, de origen alimentario, son laboriosos y consume mucho tiempo. Esta situación, aunada a la demanda por resultados inmediatos y a los avances tecnológicos, ha conducido al desarrollo de una amplia gama de métodos rápidos en las últimas décadas. En base a esto, la presente revisión describe las ventajas y limitaciones de los principales métodos moleculares utilizados en la detección e identificación de microorganismos patógenos transmitidos por alimentos. Para ello, se consideró la actualidad de la información consultada, el análisis objetivo de la temática y su alcance. La literatura reciente reporta un número significativo de técnicas moleculares, alternativas, sensibles y selectivas para la detección, enumeración e identificación de microorganismos patógenos en alimentos, siendo la reacción en cadena de la polimerasa (PCR la plataforma más popular, mientras que la secuenciación de alto rendimiento se perfila como una técnica de gran aplicabilidad a futuro. Sin embargo, aun con todas las ventajas que ofrecen estas novedosas metodologías, no se deben pasar por alto sus limitaciones. Así, por ejemplo, los métodos moleculares no constituyen protocolos estandarizados, lo que dificulta su utilización en algunos casos. Por esta razón se debe trabajar arduamente para superar tales limitaciones y mejorar la aplicación de estas técnicas en matrices tan complejas como los sistemas alimenticios.

  11. Uncertainty Propagation in Monte Carlo Depletion Analysis

    International Nuclear Information System (INIS)

    Shim, Hyung Jin; Kim, Yeong-il; Park, Ho Jin; Joo, Han Gyu; Kim, Chang Hyo

    2008-01-01

    A new formulation aimed at quantifying uncertainties of Monte Carlo (MC) tallies such as k eff and the microscopic reaction rates of nuclides and nuclide number densities in MC depletion analysis and examining their propagation behaviour as a function of depletion time step (DTS) is presented. It is shown that the variance of a given MC tally used as a measure of its uncertainty in this formulation arises from four sources; the statistical uncertainty of the MC tally, uncertainties of microscopic cross sections and nuclide number densities, and the cross correlations between them and the contribution of the latter three sources can be determined by computing the correlation coefficients between the uncertain variables. It is also shown that the variance of any given nuclide number density at the end of each DTS stems from uncertainties of the nuclide number densities (NND) and microscopic reaction rates (MRR) of nuclides at the beginning of each DTS and they are determined by computing correlation coefficients between these two uncertain variables. To test the viability of the formulation, we conducted MC depletion analysis for two sample depletion problems involving a simplified 7x7 fuel assembly (FA) and a 17x17 PWR FA, determined number densities of uranium and plutonium isotopes and their variances as well as k ∞ and its variance as a function of DTS, and demonstrated the applicability of the new formulation for uncertainty propagation analysis that need be followed in MC depletion computations. (authors)

  12. A general approach to error propagation

    International Nuclear Information System (INIS)

    Sanborn, J.B.

    1987-01-01

    A computational approach to error propagation is explained. It is shown that the application of the first-order Taylor theory to a fairly general expression representing an inventory or inventory-difference quantity leads naturally to a data structure that is useful for structuring error-propagation calculations. This data structure incorporates six types of data entities: (1) the objects in the material balance, (2) numerical parameters that describe these objects, (3) groups or sets of objects, (4) the terms which make up the material-balance equation, (5) the errors or sources of variance and (6) the functions or subroutines that represent Taylor partial derivatives. A simple algorithm based on this data structure can be defined using formulas that are sums of squares of sums. The data structures and algorithms described above have been implemented as computer software in FORTRAN for IBM PC-type machines. A free-form data-entry format allows users to separate data as they wish into separate files and enter data using a text editor. The program has been applied to the computation of limits of error for inventory differences (LEIDs) within the DOE complex. 1 ref., 3 figs

  13. Simulation of ultrasound propagation in bone

    Science.gov (United States)

    Kaufman, Jonathan J.; Luo, Gangming; Siffert, Robert S.

    2004-10-01

    Ultrasound has been proposed as a means to noninvasively assess bone and, particularly, bone strength and fracture risk, as for example in osteoporosis. Because strength is a function of both mineral density and architecture, ultrasound has the potential to provide more accurate measurement of bone integrity than, for example, with x-ray absorptiometric methods. Although some of this potential has already been realized-a number of clinical devices are presently available-there is still much that is unknown regarding the interaction of ultrasound with bone. Because of the inherent complexity of the propagation medium, few analytic solutions exist with practical application. For this reason, ultrasound simulation techniques have been developed and applied to a number of different problems of interest in ultrasonic bone assessment. Both 2D and 3D simulation results will be presented, including the effects of architecture and density on the received waveform, propagation effects of both cortical and trabecular bone, and the relative contributions of scattering and absorption to attenuation in trabecular bone. The results of these simulation studies should lead to improved understanding and ultimately to more effective clinical devices for ultrasound bone assessment. [This work was supported by The Carroll and Milton Petrie Foundation and by SBIR Grant No. 1R43RR16750 from the National Center for Research Resources of the NIH.

  14. VEGETATIVE PROPAGATION OF Schizolobium amazonicum BY cutting

    Directory of Open Access Journals (Sweden)

    Poliana Coqueiro Dias

    2015-09-01

    Full Text Available The aim of this study was to develop a methodology for the vegetative propagation of paricá (Schizolobium amazonicum through cutting, evaluating the effect of IBA (0, 8000, 16000 and 32,000 mg.L-1 on rooting of apical and intermediate stakes. The base of the cuttings were dipped in IBA solution for 10 seconds and then were staked in polyethylene tubes of 110 cm³, filled with organic substrate (Bioplant®. The irrigation of the seedlings was carried out by means of a nebulization system with a uniform flow rate of 7 L.h-1. After 40 days, were evaluated: percentage of survival, rooting percentage, percentage of roots observed at the lower end of the plastic tube, average number of roots, length of roots, presence of calluses, vigor and root dry matter. The results for the characteristics evaluated, with emphasis on survival, showed the highest averages were obtained at intermediate stakes, regardless of the dose of IBA. The highest rooting percentage, root number, length and dry mass of roots, in both types of cuttings was obtained with the highest dose tested of AIB (32,000 mg.L-1. Based on these results, it is concluded that the technique of cutting associated with application of plant growth regulators can be used for vegetative propagation of S. amazonicum.

  15. The nature of the S-linear algebra: For an S-propagator

    OpenAIRE

    Strati, Francesco

    2012-01-01

    This paper is intended to analyse an S-linear algebra’s application so as to build an S-propagator's concept. In particular we shall study a semi -deterministic propagator via superposition (it is intended the Carfì ́s notion of superposition).

  16. The optics of gyrotropic crystals in the field of two counter-propagating ultrasound waves

    International Nuclear Information System (INIS)

    Gevorgyan, A H; Harutyunyan, E M; Hovhannisyan, M A; Matinyan, G K

    2014-01-01

    We consider oblique light propagation through a layer of a gyrotropic crystal in the field of two counter-propagating ultrasound waves. The problem is solved by Ambartsumyan's layer addition modified method. The results of the reflection spectra for different values of the problem parameters are presented. The possibilities of such system applications are discussed.

  17. Propagation loss model comparisons on selected scenarios from the Weston memorial workshop

    NARCIS (Netherlands)

    Sertlek, H.O.; Ainslie, M.A.

    2013-01-01

    The accurate and stable calculation of underwater acoustic propagation is needed for applications such as sonar performance prediction, noise mapping and acoustic communication. In this work, some widely used acoustic propagation models, based on different methods such as normal mode, ray tracing,

  18. The propagator of stochastic electrodynamics

    Science.gov (United States)

    Cavalleri, G.

    1981-01-01

    The "elementary propagator" for the position of a free charged particle subject to the zero-point electromagnetic field with Lorentz-invariant spectral density ~ω3 is obtained. The nonstationary process for the position is solved by the stationary process for the acceleration. The dispersion of the position elementary propagator is compared with that of quantum electrodynamics. Finally, the evolution of the probability density is obtained starting from an initial distribution confined in a small volume and with a Gaussian distribution in the velocities. The resulting probability density for the position turns out to be equal, to within radiative corrections, to ψψ* where ψ is the Kennard wave packet. If the radiative corrections are retained, the present result is new since the corresponding expression in quantum electrodynamics has not yet been found. Besides preceding quantum electrodynamics for this problem, no renormalization is required in stochastic electrodynamics.

  19. Interprocedural Analysis with Lazy Propagation

    DEFF Research Database (Denmark)

    Jensen, Simon Holm; Møller, Anders; Thiemann, Peter

    2010-01-01

    We propose lazy propagation as a technique for flow- and context-sensitive interprocedural analysis of programs with objects and first-class functions where transfer functions may not be distributive. The technique is described formally as a systematic modification of a variant of the monotone fr...... framework and its theoretical properties are shown. It is implemented in a type analysis tool for JavaScript where it results in a significant improvement in performance....

  20. Crack propagation in dynamic thermoelasticity

    International Nuclear Information System (INIS)

    Bui, H.D.

    1980-01-01

    We study the singular thermoelastic fields near the crack tip, in the linear strain assumption. The equations are coupled and non linear. The asymptotic expansions of the displacement and the temperature are given for the first and the second order. It is shown that the temperature is singular when the crack propagates. However, this field does not change the dominant singularity of the mechanical field which is the same as that obtained in the theory of isothermal elasticity [fr

  1. Information Propagation on Permissionless Blockchains

    OpenAIRE

    Ersoy, Oguzhan; Ren, Zhijie; Erkin, Zekeriya; Lagendijk, Reginald L.

    2017-01-01

    Blockchain technology, as a decentralized and non-hierarchical platform, has the potential to replace centralized systems. Yet, there are several challenges inherent in the blockchain structure. One of the deficiencies of the existing blockchains is a convenient information propagation technique enhancing incentive-compatibility and bandwidth efficiency. The transition from a centralized system into distributed one brings along game theoretical concerns. Especially for the permissionless bloc...

  2. Quantum noise and superluminal propagation

    International Nuclear Information System (INIS)

    Segev, Bilha; Milonni, Peter W.; Babb, James F.; Chiao, Raymond Y.

    2000-01-01

    Causal ''superluminal'' effects have recently been observed and discussed in various contexts. The question arises whether such effects could be observed with extremely weak pulses, and what would prevent the observation of an ''optical tachyon.'' Aharonov, Reznik, and Stern (ARS) [Phys. Rev. Lett. 81, 2190 (1998)] have argued that quantum noise will preclude the observation of a superluminal group velocity when the pulse consists of one or a few photons. In this paper we reconsider this question both in a general framework and in the specific example, suggested by Chiao, Kozhekin, and Kurizki (CKK) [Phys. Rev. 77, 1254 (1996)], of off-resonant, short-pulse propagation in an optical amplifier. We derive in the case of the amplifier a signal-to-noise ratio that is consistent with the general ARS conclusions when we impose their criteria for distinguishing between superluminal propagation and propagation at the speed c. However, results consistent with the semiclassical arguments of CKK are obtained if weaker criteria are imposed, in which case the signal can exceed the noise without being ''exponentially large.'' We show that the quantum fluctuations of the field considered by ARS are closely related to superfluorescence noise. More generally, we consider the implications of unitarity for superluminal propagation and quantum noise and study, in addition to the complete and truncated wave packets considered by ARS, the residual wave packet formed by their difference. This leads to the conclusion that the noise is mostly luminal and delayed with respect to the superluminal signal. In the limit of a very weak incident signal pulse, the superluminal signal will be dominated by the noise part, and the signal-to-noise ratio will therefore be very small. (c) 2000 The American Physical Society

  3. Propagation functions in pseudoparticle fields

    International Nuclear Information System (INIS)

    Brown, L.S.; Carlitz, R.D.; Creamer, D.B.; Lee, C.

    1978-01-01

    The Green's functions for massless spinor and vector particles propagating in a self-dual but otherwise arbitrary non-Abelian gauge field are shown to be completely determined by the corrresponding Green's functions of scalar particles. Simple, explicit algebraic expressions are constructed for the scalar Green's functions of isospin-1/2 and isospin-1 particles in the self-dual field of a configuration of n pseudoparticles described by 5n arbitrary parameters

  4. Propagation calculation for reactor cases

    Energy Technology Data Exchange (ETDEWEB)

    Yang Yanhua [School of Power and Energy Engineering, Shanghai Jiao Tong Univ., Shanghai (China); Moriyama, K.; Maruyama, Y.; Nakamura, H.; Hashimoto, K. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2000-11-01

    The propagation of steam explosion for real reactor geometry and conditions are investigated by using the computer code JASMINE-pro. The ex-vessel steam explosion is considered, which is described as follow: during the accident of reactor core meltdown, the molten core melts a hole at the bottom of reactor vessel and causes the higher temperature core fuel being leaked into the water pool below reactor vessel. During the melt-water mixing interaction process, the high temperature melt evaporates the cool water at an extreme high rate and might induce a steam explosion. A steam explosion could experience first the premixing phase and then the propagation explosion phase. For a propagation calculation, we should know the information about the initial fragmentation time, the total melt mass, premixing region size, initial void fraction and distribution of the melt volume fraction, and so on. All the initial conditions used in this calculation are based on analyses from some simple assumptions and the observation from the experiments. The results show that the most important parameter for the initial condition of this phase is the total mass and its initial distribution. This gives the requirement for a premixing calculation. On the other hand, for higher melt volume fraction case, the fragmentation is strong so that the local pressure can exceed over the EOS maximum pressure of the code, which lead to the incorrect calculation or divergence of the calculation. (Suetake, M.)

  5. Propagating separable equalities in an MDD store

    DEFF Research Database (Denmark)

    Hadzic, Tarik; Hooker, John N.; Tiedemann, Peter

    2008-01-01

    We present a propagator that achieves MDD consistency for a separable equality over an MDD (multivalued decision diagram) store in pseudo-polynomial time. We integrate the propagator into a constraint solver based on an MDD store introduced in [1]. Our experiments show that the new propagator pro...... provides substantial computational advantage over propagation of two inequality constraints, and that the advantage increases when the maximum width of the MDD store increases....

  6. Sociālo tīklu un platformas "Facebook" ietekme uz patērētāja pirkuma lēmuma pieņemšanas procesu.

    OpenAIRE

    Ķiksis, Kristiāns

    2017-01-01

    Bakalaura darba tēma ir “Sociālo tīklu un platformas “Facebook” ietekme uz patērētāja pirkuma lēmuma pieņemšanas procesu”. Veiktā darba mērķis ir izskaidrot, kāpēc, kad un kā sociālie mediji ir ietekmējuši patērētāju lēmumu pieņemšanas procesu. Teorētiskā daļa sastāv no 4 sadaļām- patērētāju uzvedība, sociālie mediji, sociālo mediju ietekme uz patērētājiem, kā arī platformas “Facebook” iespējas. Darbs ietver 4 nodaļas. Bakalaura darba teorētiskajā daļā apkopoti materiāli par patērētāju uzvedī...

  7. Ultrasonic propagation velocity in magnetic and magnetorheological fluids due to an external magnetic field

    International Nuclear Information System (INIS)

    Bramantya, M A; Sawada, T; Motozawa, M

    2010-01-01

    Ultrasonic propagation velocity in a magnetic fluid (MF) and magnetorheological fluid (MRF) changes with the application of an external magnetic field. The formation of clustering structures inside the MF and MRF clearly has an influence on the ultrasonic propagation velocity. Therefore, we propose a qualitative analysis of these structures by measuring properties of ultrasonic propagation. Since MF and MRF are opaque, non-contact inspection using the ultrasonic technique can be very useful for analyzing the inner structures of MF and MRF. In this study, we measured ultrasonic propagation velocity in a hydrocarbon-based MF and MRF precisely. Based on these results, the clustering structures of these fluids are analyzed experimentally in terms of elapsed time dependence and the effect of external magnetic field strength. The results reveal hysteresis and anisotropy in the ultrasonic propagation velocity. We also discuss differences of ultrasonic propagation velocity between MF and MRF.

  8. Fire Propagation Tracing Model in the Explicit Treatment of Events of Fire PSA

    International Nuclear Information System (INIS)

    Lim, Ho Gon; Han, Sang Hoon; Yang, Jun Eon

    2010-01-01

    The fire propagation model in a fire PSA has not been considered analytically instead a simplified analyst's intuition was used to consider the fire propagation path. A fire propagation equation is developed to trace all the propagation paths in the fire area in which a zone is defined to identify various fire ignition sources. An initiation of fire is assumed to take place in a zone. Then, the propagation is modeled with a Boolean equation. Since the explicit fire PSA modeling requires an exclusive event set to sum up the..., exclusive event sets are derived from the fire propagation equation. As an example, we show the exclusive set for a 2x3 rectangular fire zone. Also, the applicability the developed fire equation is discussed when the number of zone increases including the limitation of the explicit fire PSA modeling method

  9. Fast Heat Pulse Propagation by Turbulence Spreading

    DEFF Research Database (Denmark)

    Naulin, Volker; Juul Rasmussen, Jens; Mantica, Paola

    2009-01-01

    The propagation of a cold pulse initiated by edge cooling in JET is compared to propagation of the heat wave originating from a modulation of the heating source roughly at mid radius. It is found that the propagation of the cold pulse is by far faster than what could be predicted on the basis of ...

  10. Semiclassical scalar propagators in curved backgrounds: Formalism and ambiguities

    International Nuclear Information System (INIS)

    Grain, J.; Barrau, A.

    2007-01-01

    The phenomenology of quantum systems in curved space-times is among the most fascinating fields of physics, allowing--often at the gedankenexperiment level--constraints on tentative theories of quantum gravity. Determining the dynamics of fields in curved backgrounds remains, however, a complicated task because of the highly intricate partial differential equations involved, especially when the space metric exhibits no symmetry. In this article, we provide--in a pedagogical way--a general formalism to determine this dynamics at the semiclassical order. To this purpose, a generic expression for the semiclassical propagator is computed and the equation of motion for the probability four-current is derived. Those results underline a direct analogy between the computation of the propagator in general relativistic quantum mechanics and the computation of the propagator for stationary systems in nonrelativistic quantum mechanics. A possible application of this formalism to curvature-induced quantum interferences is also discussed

  11. Prepulse effect on intense femtosecond laser pulse propagation in gas

    International Nuclear Information System (INIS)

    Giulietti, Antonio; Tomassini, Paolo; Galimberti, Marco; Giulietti, Danilo; Gizzi, Leonida A.; Koester, Petra; Labate, Luca; Ceccotti, Tiberio; D'Oliveira, Pascal; Auguste, Thierry; Monot, Pascal; Martin, Philippe

    2006-01-01

    The propagation of an ultrashort laser pulse can be affected by the light reaching the medium before the pulse. This can cause a serious drawback to possible applications. The propagation in He of an intense 60-fs pulse delivered by a Ti:sapphire laser in the chirped pulse amplification (CPA) mode has been investigated in conditions of interest for laser-plasma acceleration of electrons. The effects of both nanosecond amplified spontaneous emission and picosecond pedestals have been clearly identified. There is evidence that such effects are basically of refractive nature and that they are not detrimental for the propagation of a CPA pulse focused to moderately relativistic intensity. The observations are fully consistent with numerical simulations and can contribute to the search of a stable regime for laser acceleration

  12. Beam propagation through a gaseous reactor: classical transport

    International Nuclear Information System (INIS)

    Yu, S.S.; Buchanan, H.L.; Lee, E.P.; Chambers, F.W.

    1979-01-01

    The present calculations are applicable to any beam geometry with cylindrical symmetry, including the converging beam geometry (large entrance port with radius > or approx. = 10 cm), as well as the pencil-shaped beam (small porthole with radius approx. mm). The small porthole is clearly advantageous from the reactor vessel design point of view. While the physics of the latter mode of propagation may be more complex, analyses up to this point have not revealed any detrimental instability effects that will inhibit propagation. In fact, the large perpendicular velocity v/sub perpendicular/ that the pinched mode can accommodate provides a mechanism for the quenching of filamentary instability. Furthermore, this mode of propagation can withstand more ion scattering and is not subject to the upper bound on pressure (p < 10 torr) which is imposed on the converging beam mode

  13. Electromagnetic wave propagation in relativistic magnetized plasmas

    International Nuclear Information System (INIS)

    Weiss, I.

    1985-01-01

    An improved mathematical technique and a new code for deriving the conductivity tensor for collisionless plasmas have been developed. The method is applicable to a very general case, including both hot (relativistic) and cold magnetized plasmas, with only isotropic equilibrium distributions being considered here. The usual derivation starts from the relativistic Vlasov equation and leads to an integration over an infinite sum of Bessel functions which has to be done numerically. In the new solution the integration is carried out over a product of two Bessel functions only. This reduces the computing time very significantly. An added advantage over existing codes is our capability to perform the computations for waves propagating obliquely to the magnetic field. Both improvements greatly facilitate investigations of properties of the plasma under conditions hitherto unexplored

  14. Propagating wave correlations in complex systems

    International Nuclear Information System (INIS)

    Creagh, Stephen C; Gradoni, Gabriele; Hartmann, Timo; Tanner, Gregor

    2017-01-01

    We describe a novel approach for computing wave correlation functions inside finite spatial domains driven by complex and statistical sources. By exploiting semiclassical approximations, we provide explicit algorithms to calculate the local mean of these correlation functions in terms of the underlying classical dynamics. By defining appropriate ensemble averages, we show that fluctuations about the mean can be characterised in terms of classical correlations. We give in particular an explicit expression relating fluctuations of diagonal contributions to those of the full wave correlation function. The methods have a wide range of applications both in quantum mechanics and for classical wave problems such as in vibro-acoustics and electromagnetism. We apply the methods here to simple quantum systems, so-called quantum maps, which model the behaviour of generic problems on Poincaré sections. Although low-dimensional, these models exhibit a chaotic classical limit and share common characteristics with wave propagation in complex structures. (paper)

  15. Data Stream Clustering With Affinity Propagation

    KAUST Repository

    Zhang, Xiangliang; Furtlehner, Cyril; Germain-Renaud, Cecile; Sebag, Michele

    2014-01-01

    Data stream clustering provides insights into the underlying patterns of data flows. This paper focuses on selecting the best representatives from clusters of streaming data. There are two main challenges: how to cluster with the best representatives and how to handle the evolving patterns that are important characteristics of streaming data with dynamic distributions. We employ the Affinity Propagation (AP) algorithm presented in 2007 by Frey and Dueck for the first challenge, as it offers good guarantees of clustering optimality for selecting exemplars. The second challenging problem is solved by change detection. The presented StrAP algorithm combines AP with a statistical change point detection test; the clustering model is rebuilt whenever the test detects a change in the underlying data distribution. Besides the validation on two benchmark data sets, the presented algorithm is validated on a real-world application, monitoring the data flow of jobs submitted to the EGEE grid.

  16. Data Stream Clustering With Affinity Propagation

    KAUST Repository

    Zhang, Xiangliang

    2014-07-09

    Data stream clustering provides insights into the underlying patterns of data flows. This paper focuses on selecting the best representatives from clusters of streaming data. There are two main challenges: how to cluster with the best representatives and how to handle the evolving patterns that are important characteristics of streaming data with dynamic distributions. We employ the Affinity Propagation (AP) algorithm presented in 2007 by Frey and Dueck for the first challenge, as it offers good guarantees of clustering optimality for selecting exemplars. The second challenging problem is solved by change detection. The presented StrAP algorithm combines AP with a statistical change point detection test; the clustering model is rebuilt whenever the test detects a change in the underlying data distribution. Besides the validation on two benchmark data sets, the presented algorithm is validated on a real-world application, monitoring the data flow of jobs submitted to the EGEE grid.

  17. Large amplitude parallel propagating electromagnetic oscillitons

    International Nuclear Information System (INIS)

    Cattaert, Tom; Verheest, Frank

    2005-01-01

    Earlier systematic nonlinear treatments of parallel propagating electromagnetic waves have been given within a fluid dynamic approach, in a frame where the nonlinear structures are stationary and various constraining first integrals can be obtained. This has lead to the concept of oscillitons that has found application in various space plasmas. The present paper differs in three main aspects from the previous studies: first, the invariants are derived in the plasma frame, as customary in the Sagdeev method, thus retaining in Maxwell's equations all possible effects. Second, a single differential equation is obtained for the parallel fluid velocity, in a form reminiscent of the Sagdeev integrals, hence allowing a fully nonlinear discussion of the oscilliton properties, at such amplitudes as the underlying Mach number restrictions allow. Third, the transition to weakly nonlinear whistler oscillitons is done in an analytical rather than a numerical fashion

  18. Controlling wave propagation through nonlinear engineered granular systems

    Science.gov (United States)

    Leonard, Andrea

    We study the fundamental dynamic behavior of a special class of ordered granular systems in order to design new, structured materials with unique physical properties. The dynamic properties of granular systems are dictated by the nonlinear, Hertzian, potential in compression and zero tensile strength resulting from the discrete material structure. Engineering the underlying particle arrangement of granular systems allows for unique dynamic properties, not observed in natural, disordered granular media. While extensive studies on 1D granular crystals have suggested their usefulness for a variety of engineering applications, considerably less attention has been given to higher-dimensional systems. The extension of these studies in higher dimensions could enable the discovery of richer physical phenomena not possible in 1D, such as spatial redirection and anisotropic energy trapping. We present experiments, numerical simulation (based on a discrete particle model), and in some cases theoretical predictions for several engineered granular systems, studying the effects of particle arrangement on the highly nonlinear transient wave propagation to develop means for controlling the wave propagation pathways. The first component of this thesis studies the stress wave propagation resulting from a localized impulsive loading for three different 2D particle lattice structures: square, centered square, and hexagonal granular crystals. By varying the lattice structure, we observe a wide range of properties for the propagating stress waves: quasi-1D solitary wave propagation, fully 2D wave propagation with tunable wave front shapes, and 2D pulsed wave propagation. Additionally the effects of weak disorder, inevitably present in real granular systems, are investigated. The second half of this thesis studies the solitary wave propagation through 2D and 3D ordered networks of granular chains, reducing the effective density compared to granular crystals by selectively placing wave

  19. Reklāmas ietekme uz patērētāju izvēles veikšanā

    OpenAIRE

    Asejevs, Aleksandrs

    2012-01-01

    Bakalaura darba tēma izvēlēta „Reklāmas ietekme uz patērētāju izvēles veikšanā”. Pastiprinoties konkurencei valstu iekšzemes tirgū, uzņēmumi savas preces un pakalpojumus virza globālajā tirgū. Starptautiskajā mārketingā reklāma tiek izmantota kā viens no mārketinga komunikācijas līdzekļiem, ar kura palīdzību uzņēmumi patērētajiem virzītu savas preces un pakalpojumus. Darba mērķis: balstoties uz veiktās aptaujas rezultātiem, izstrādāt priekšlikumus reklāmas pilnveidošanai Latvijā. Lai...

  20. Quality-by-Design (QbD): An integrated process analytical technology (PAT) approach for a dynamic pharmaceutical co-precipitation process characterization and process design space development.

    Science.gov (United States)

    Wu, Huiquan; White, Maury; Khan, Mansoor A

    2011-02-28

    The aim of this work was to develop an integrated process analytical technology (PAT) approach for a dynamic pharmaceutical co-precipitation process characterization and design space development. A dynamic co-precipitation process by gradually introducing water to the ternary system of naproxen-Eudragit L100-alcohol was monitored at real-time in situ via Lasentec FBRM and PVM. 3D map of count-time-chord length revealed three distinguishable process stages: incubation, transition, and steady-state. The effects of high risk process variables (slurry temperature, stirring rate, and water addition rate) on both derived co-precipitation process rates and final chord-length-distribution were evaluated systematically using a 3(3) full factorial design. Critical process variables were identified via ANOVA for both transition and steady state. General linear models (GLM) were then used for parameter estimation for each critical variable. Clear trends about effects of each critical variable during transition and steady state were found by GLM and were interpreted using fundamental process principles and Nyvlt's transfer model. Neural network models were able to link process variables with response variables at transition and steady state with R(2) of 0.88-0.98. PVM images evidenced nucleation and crystal growth. Contour plots illustrated design space via critical process variables' ranges. It demonstrated the utility of integrated PAT approach for QbD development. Published by Elsevier B.V.

  1. Implementation of an advanced hybrid MPC-PID control system using PAT tools into a direct compaction continuous pharmaceutical tablet manufacturing pilot plant.

    Science.gov (United States)

    Singh, Ravendra; Sahay, Abhishek; Karry, Krizia M; Muzzio, Fernando; Ierapetritou, Marianthi; Ramachandran, Rohit

    2014-10-01

    It is desirable for a pharmaceutical final dosage form to be manufactured through a quality by design (QbD)-based approach rather than a quality by testing (QbT) approach. An automatic feedback control system coupled with PAT tools that is part of the QbD paradigm shift, has the potential to ensure that the pre-defined end product quality attributes are met in a time and cost efficient manner. In this work, an advanced hybrid MPC-PID control architecture coupled with real time inline/online monitoring tools and principal components analysis (PCA) based additional supervisory control layer has been proposed for a continuous direct compaction tablet manufacturing process. The advantages of both MPC and PID have been utilized in a hybrid scheme. The control hardware and software integration and implementation of the control system has been demonstrated using feeders and blending unit operation of a continuous tablet manufacturing pilot plant and an NIR based PAT tool. The advanced hybrid MPC-PID control scheme leads to enhanced control loop performance of the critical quality attributes in comparison to a regulatory (e.g. PID) control scheme indicating its potential to improve pharmaceutical product quality. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Semiclassical propagator of the Wigner function.

    Science.gov (United States)

    Dittrich, Thomas; Viviescas, Carlos; Sandoval, Luis

    2006-02-24

    Propagation of the Wigner function is studied on two levels of semiclassical propagation: one based on the Van Vleck propagator, the other on phase-space path integration. Leading quantum corrections to the classical Liouville propagator take the form of a time-dependent quantum spot. Its oscillatory structure depends on whether the underlying classical flow is elliptic or hyperbolic. It can be interpreted as the result of interference of a pair of classical trajectories, indicating how quantum coherences are to be propagated semiclassically in phase space. The phase-space path-integral approach allows for a finer resolution of the quantum spot in terms of Airy functions.

  3. The propagator of quantum gravity in minisuperspace

    International Nuclear Information System (INIS)

    Louko, J.

    1985-04-01

    We study the quantum gravitational propagation amplitude between two spacelike three-surfaces in minisuperspaces where the supermomentum constraints are identically satisfied. We derive a well-defined path integral formula for the propagator and show that the propagator is an inverse of the canonical Hamiltonian operator. In an exactly solvable deSitter minisuperspace model the propagator is found to obey semi-classically correct boundary conditions. We discuss the implications for the full theory and suggest an approach to unravelling the physical meaning of the propagator. (orig.)

  4. Tropospheric radiowave propagation beyond the horizon

    CERN Document Server

    Du Castel, François

    1966-01-01

    Tropospheric Radiowave Propagation Beyond the Horizon deals with developments concerning the tropospheric propagation of ultra-short radio waves beyond the horizon, with emphasis on the relationship between the theoretical and the experimental. Topics covered include the general conditions of propagation in the troposphere; general characteristics of propagation beyond the horizon; and attenuation in propagation. This volume is comprised of six chapters and begins with a brief historical look at the various stages that have brought the technique of transhorizon links to its state of developmen

  5. Light propagation in linear optical media

    CERN Document Server

    Gillen, Glen D; Guha, Shekhar

    2013-01-01

    Light Propagation in Linear Optical Media describes light propagation in linear media by expanding on diffraction theories beyond what is available in classic optics books. In one volume, this book combines the treatment of light propagation through various media, interfaces, and apertures using scalar and vector diffraction theories. After covering the fundamentals of light and physical optics, the authors discuss light traveling within an anisotropic crystal and present mathematical models for light propagation across planar boundaries between different media. They describe the propagation o

  6. Propagation phenomena in real world networks

    CERN Document Server

    Fay, Damien; Gabryś, Bogdan

    2015-01-01

    Propagation, which looks at spreading in complex networks, can be seen from many viewpoints; it is undesirable, or desirable, controllable, the mechanisms generating that propagation can be the topic of interest, but in the end all depends on the setting. This book covers leading research on a wide spectrum of propagation phenomenon and the techniques currently used in its modelling, prediction, analysis and control. Fourteen papers range over topics including epidemic models, models for trust inference, coverage strategies for networks, vehicle flow propagation, bio-inspired routing algorithms, P2P botnet attacks and defences, fault propagation in gene-cellular networks, malware propagation for mobile networks, information propagation in crisis situations, financial contagion in interbank networks, and finally how to maximize the spread of influence in social networks. The compendium will be of interest to researchers, those working in social networking, communications and finance and is aimed at providin...

  7. Multispecimen fatigue crack propagation testing

    International Nuclear Information System (INIS)

    Ermi, A.M.; Bauer, R.E.; Chin, B.A.; Straalsund, J.L.

    1981-01-01

    Chains of miniature center-cracked-tension specimens were tested on a conventional testing machine and on a prototypic in-reactor fatigue machine as part of the fusion reactor materials alloy development program. Annealed and 20 percent cold-worked 316 stainless steel specimens were cycled under various conditions of temperature, frequency, stress ratio and chain length. Crack growth rates determined from multispecimen visual measurements and from an electrical potential technique were consistent with those obtained by conventional test methods. Results demonstrate that multispecimen chain testing is a valid method of obtaining fatigue crack propagation information for alloy development. 8 refs

  8. Radio Propagation into Modern Buildings

    DEFF Research Database (Denmark)

    Rodriguez Larrad, Ignacio; Nguyen, Huan Cong; Jørgensen, Niels T.K.

    2014-01-01

    Energy-efficient buildings are gaining momentum in order to comply with the new energy regulations. Especially in northern cold countries, thick reinforced walls and energy-efficient windows composed of several layers of glass plus metal coating are becoming the de facto elements in modern building...... constructions. These materials are used in favor of achieving a proper level of thermal isolation, but it has been noticed that they can impact heavily on radio signal propagation. This paper presents a measurement-based analysis of the outdoor-to-indoor attenuation experienced in several modern constructions...

  9. Fast imaging of streamer propagation

    International Nuclear Information System (INIS)

    Veldhuizen, E.M. van; Baede, A.H.F.M.; Hayashi, D.; Rutgers, W.R.

    2001-01-01

    Recently measurement methods are becoming available to study the corona discharge in more detail. One of the most promising methods is laser-induced fluorescence to determine radical density. Recent improvements in CCD cameras makes it now possible to improve measurements of the discharge structure to a resolution of 1 ns in time and 10 μm in space. This paper shows the first results of the spontaneous emission of a point-to-plane corona discharge in air using such a camera. It clearly indicates that the 2-D approach for streamer propagation under these conditions is insufficient

  10. Fast imaging of streamer propagation

    Energy Technology Data Exchange (ETDEWEB)

    Veldhuizen, E.M. van; Baede, A.H.F.M.; Hayashi, D.; Rutgers, W.R. [Eindhoven Univ. of Technology (Netherlands). Dept. of Applied Physics

    2001-07-01

    Recently measurement methods are becoming available to study the corona discharge in more detail. One of the most promising methods is laser-induced fluorescence to determine radical density. Recent improvements in CCD cameras makes it now possible to improve measurements of the discharge structure to a resolution of 1 ns in time and 10 {mu}m in space. This paper shows the first results of the spontaneous emission of a point-to-plane corona discharge in air using such a camera. It clearly indicates that the 2-D approach for streamer propagation under these conditions is insufficient.

  11. Modification Propagation in Complex Networks

    Science.gov (United States)

    Mouronte, Mary Luz; Vargas, María Luisa; Moyano, Luis Gregorio; Algarra, Francisco Javier García; Del Pozo, Luis Salvador

    To keep up with rapidly changing conditions, business systems and their associated networks are growing increasingly intricate as never before. By doing this, network management and operation costs not only rise, but are difficult even to measure. This fact must be regarded as a major constraint to system optimization initiatives, as well as a setback to derived economic benefits. In this work we introduce a simple model in order to estimate the relative cost associated to modification propagation in complex architectures. Our model can be used to anticipate costs caused by network evolution, as well as for planning and evaluating future architecture development while providing benefit optimization.

  12. Probabilistic aspects of fatigue crack propagation data for zirconium-2.5 % niobium

    International Nuclear Information System (INIS)

    Wilkins, B.J.S.; Reich, A.R.

    1976-11-01

    Fatigue crack propagation data for Zr-2.5 % Nb pressure tube material at 20 and 400 deg C are presented. The practical application of these data in terms of error analysis and extrapolation errors is discussed. (author)

  13. Studies of nonlinear femtosecond pulse propagation in bulk materials

    Science.gov (United States)

    Eaton, Hilary Kaye

    2000-10-01

    Femtosecond pulse lasers are finding widespread application in a variety of fields including medical research, optical switching and communications, plasma formation, high harmonic generation, and wavepacket formation and control. As the number of applications for femtosecond pulses increases, so does the need to fully understand the linear and nonlinear processes involved in propagating these pulses through materials under various conditions. Recent advances in pulse measurement techniques, such as frequency-resolved optical gating (FROG), allow measurement of the full electric field of the pulse and have made detailed investigations of short- pulse propagation effects feasible. In this thesis, I present detailed experimental studies of my work involving nonlinear propagation of femtosecond pulses in bulk media. Studies of plane-wave propagation in fused silica extend the SHG form of FROG from a simple pulse diagnostic to a useful method of interrogating the nonlinear response of a material. Studies of nonlinear propagation are also performed in a regime where temporal pulse splitting occurs. Experimental results are compared with a three- dimensional nonlinear Schrödinger equation. This comparison fuels the development of a more complete model for pulse splitting. Experiments are also performed at peak input powers above those at which pulse splitting is observed. At these higher intensities, a broadband continuum is generated. This work presents a detailed study of continuum behavior and power loss as well as the first near-field spatial- spectral measurements of the generated continuum light. Nonlinear plane-wave propagation of short pulses in liquids is also investigated, and a non-instantaneous nonlinearity with a surprisingly short response time of 10 fs is observed in methanol. Experiments in water confirm that this effect in methanol is indeed real. Possible explanations for the observed effect are discussed and several are experimentally rejected. This

  14. Supramolecular core-shell nanoparticles for photoconductive device applications

    Science.gov (United States)

    Cheng, Chih-Chia; Chen, Jem-Kun; Shieh, Yeong-Tarng; Lee, Duu-Jong

    2016-08-01

    We report a breakthrough discovery involving supramolecular-based strategies to construct novel core-shell heterojunction nanoparticles with hydrophilic adenine-functionalized polythiophene (PAT) as the core and hydrophobic phenyl-C61-butyric acid methyl ester (PCBM) as the shell, which enables the conception of new functional supramolecular assemblies for constructing functional nanomaterials for applications in optoelectronic devices. The generated nanoparticles exhibit uniform spherical shape, well-controlled tuning of particle size with narrow size distributions, and excellent electrochemical stability in solution and the solid state owing to highly efficient energy transfer from PAT to PCBM. When the PAT/PCBM nanoparticles were fabricated into a photoconducting layer in an electronic device, the resulting device showed excellent electric conduction characteristics, including an electrically-tunable voltage-controlled switch, and high short-circuit current and open-circuit voltage. These observations demonstrate how the self-assembly of PAT/PCBM into specific nanostructures may help to promote efficient charge generation and transport processes, suggesting potential for a wide variety of applications as a promising candidate material for bulk heterojunction polymer devices.

  15. Genetic conservation and paddlefish propagation

    Science.gov (United States)

    Sloss, Brian L.; Klumb, Robert A.; Heist, Edward J.

    2009-01-01

    The conservation of genetic diversity of our natural resources is overwhelmingly one of the central foci of 21st century management practices. Three recommendations related to the conservation of paddlefish Polyodon spathula genetic diversity are to (1) identify genetic diversity at both nuclear and mitochondrial DNA loci using a suggested list of 20 sampling locations, (2) use genetic diversity estimates to develop genetic management units, and (3) identify broodstock sources to minimize effects of supplemental stocking on the genetic integrity of native paddlefish populations. We review previous genetic work on paddlefish and described key principles and concepts associated with maintaining genetic diversity within and among paddlefish populations and also present a genetic case study of current paddlefish propagation at the U.S. Fish and Wildlife Service Gavins Point National Fish Hatchery. This study confirmed that three potential sources of broodfish were genetically indistinguishable at the loci examined, allowing the management agencies cooperating on this program flexibility in sampling gametes. This study also showed significant bias in the hatchery occurred in terms of male reproductive contribution, which resulted in a shift in the genetic diversity of progeny compared to the broodfish. This shift was shown to result from differential male contributions, partially attributed to the mode of egg fertilization. Genetic insights enable implementation of a paddlefish propagation program within an adaptive management strategy that conserves inherent genetic diversity while achieving demographic goals.

  16. Quantum propagation across cosmological singularities

    Science.gov (United States)

    Gielen, Steffen; Turok, Neil

    2017-05-01

    The initial singularity is the most troubling feature of the standard cosmology, which quantum effects are hoped to resolve. In this paper, we study quantum cosmology with conformal (Weyl) invariant matter. We show that it is natural to extend the scale factor to negative values, allowing a large, collapsing universe to evolve across a quantum "bounce" into an expanding universe like ours. We compute the Feynman propagator for Friedmann-Robertson-Walker backgrounds exactly, identifying curious pathologies in the case of curved (open or closed) universes. We then include anisotropies, fixing the operator ordering of the quantum Hamiltonian by imposing covariance under field redefinitions and again finding exact solutions. We show how complex classical solutions allow one to circumvent the singularity while maintaining the validity of the semiclassical approximation. The simplest isotropic universes sit on a critical boundary, beyond which there is qualitatively different behavior, with potential for instability. Additional scalars improve the theory's stability. Finally, we study the semiclassical propagation of inhomogeneous perturbations about the flat, isotropic case, at linear and nonlinear order, showing that, at least at this level, there is no particle production across the bounce. These results form the basis for a promising new approach to quantum cosmology and the resolution of the big bang singularity.

  17. Simplified propagation of standard uncertainties

    International Nuclear Information System (INIS)

    Shull, A.H.

    1997-01-01

    An essential part of any measurement control program is adequate knowledge of the uncertainties of the measurement system standards. Only with an estimate of the standards'' uncertainties can one determine if the standard is adequate for its intended use or can one calculate the total uncertainty of the measurement process. Purchased standards usually have estimates of uncertainty on their certificates. However, when standards are prepared and characterized by a laboratory, variance propagation is required to estimate the uncertainty of the standard. Traditional variance propagation typically involves tedious use of partial derivatives, unfriendly software and the availability of statistical expertise. As a result, the uncertainty of prepared standards is often not determined or determined incorrectly. For situations meeting stated assumptions, easier shortcut methods of estimation are now available which eliminate the need for partial derivatives and require only a spreadsheet or calculator. A system of simplifying the calculations by dividing into subgroups of absolute and relative uncertainties is utilized. These methods also incorporate the International Standards Organization (ISO) concepts for combining systematic and random uncertainties as published in their Guide to the Expression of Measurement Uncertainty. Details of the simplified methods and examples of their use are included in the paper

  18. Uncertainty propagation in nuclear forensics

    International Nuclear Information System (INIS)

    Pommé, S.; Jerome, S.M.; Venchiarutti, C.

    2014-01-01

    Uncertainty propagation formulae are presented for age dating in support of nuclear forensics. The age of radioactive material in this context refers to the time elapsed since a particular radionuclide was chemically separated from its decay product(s). The decay of the parent radionuclide and ingrowth of the daughter nuclide are governed by statistical decay laws. Mathematical equations allow calculation of the age of specific nuclear material through the atom ratio between parent and daughter nuclides, or through the activity ratio provided that the daughter nuclide is also unstable. The derivation of the uncertainty formulae of the age may present some difficulty to the user community and so the exact solutions, some approximations, a graphical representation and their interpretation are presented in this work. Typical nuclides of interest are actinides in the context of non-proliferation commitments. The uncertainty analysis is applied to a set of important parent–daughter pairs and the need for more precise half-life data is examined. - Highlights: • Uncertainty propagation formulae for age dating with nuclear chronometers. • Applied to parent–daughter pairs used in nuclear forensics. • Investigated need for better half-life data

  19. Representation and propagation of imprecise and uncertain knowledge: applied to risk assessments related by polluted sites and soils; Representation et propagation de connaissances imprecises et incertaines: application a l'evaluation des risques lies aux sites et aux sols pollues

    Energy Technology Data Exchange (ETDEWEB)

    Baudrit, C

    2005-10-15

    Currently, decisions pertaining to the management of potentially polluted sites very often rely on the evaluation of risks for man and the environment. This evaluation is carried out with the help of models which simulate the transfer of pollutants from a source to a vulnerable target, for different scenarios of exposure. The selection of parameter values of these models is based as much as possible on the data collected at the time of on-site investigations (phase of diagnosis). However, due to time and financial constraints, information regarding model parameters is often incomplete and imprecise. This leads to uncertainty that needs to be accounted for the decision-making process. Uncertainty regarding model parameters may have essentially two origins. It may arise from randomness due to natural variability resulting from heterogeneity of population or the fluctuations of a quantity in time. Or it may be caused by impreciseness due to a lack of information resulting, for example, from systematic measurement errors or expert opinions. In risk assessment, no distinction is traditionally made between these two types of uncertainty, both being represented by means of a single probability distribution. So, uncertainty in risk assessment models is generally addressed within a purely probabilistic framework. This approach comes down to assuming that knowledge regarding model parameters is always of random nature (variability). Such knowledge is represented by single probability distributions typically propagated through the risk model using the Monte-Carlo technique. Even if this approach is well-known, the difficulty is to avoid an arbitrary choice of the shape of probability distributions assigned to model parameters. Indeed in the context of risk assessment related to pollutant exposure, knowledge of some parameters is often imprecise or incomplete. The use of single probability distribution to represent this type of knowledge becomes subjective and partly arbitrary

  20. Theoretical and Experimental Study on Vibration Propagation in PMMA Components in Ultrasonic Bonding Process

    Directory of Open Access Journals (Sweden)

    Yibo Sun

    2017-03-01

    Full Text Available Ultrasonic bonding has an increasing application in the micro assembly of polymeric micro-electro mechanical systems (MEMS with high requirements for fusion precision. In the ultrasonic bonding process, the propagation of ultrasonic vibration in polymer components is related to the interfacial fusion, which can be used as a monitoring parameter to control ultrasonic energy. To study the vibration propagation in viscoelastic polymer components, finite element analysis on the bonding of poly methyl methacrylate (PMMA micro connector to substrate for microfluidic system is carried out. Curves of propagated vibration amplitude corresponding to interfacial temperatures are obtained. The ultrasonic vibration propagated in PMMA components are measured through experiments. The theoretical and experimental results are contrasted to analyze the change mechanism of vibration propagation related to temperature. Based on the ultrasonic bonding process controlled by the feedback of vibration propagation, interfacial fusions at different vibration propagation states are obtained through experiments. Interfacial fusion behavior is contrasted to the propagated vibration amplitude in theoretical and experimental studies. The relation between vibration propagation and fusion degree is established with the proper parameter range for the obtained high quality bonding.

  1. Adaptive laser link reconfiguration using constraint propagation

    Science.gov (United States)

    Crone, M. S.; Julich, P. M.; Cook, L. M.

    1993-01-01

    This paper describes Harris AI research performed on the Adaptive Link Reconfiguration (ALR) study for Rome Lab, and focuses on the application of constraint propagation to the problem of link reconfiguration for the proposed space based Strategic Defense System (SDS) Brilliant Pebbles (BP) communications system. According to the concept of operations at the time of the study, laser communications will exist between BP's and to ground entry points. Long-term links typical of RF transmission will not exist. This study addressed an initial implementation of BP's based on the Global Protection Against Limited Strikes (GPALS) SDI mission. The number of satellites and rings studied was representative of this problem. An orbital dynamics program was used to generate line-of-site data for the modeled architecture. This was input into a discrete event simulation implemented in the Harris developed COnstraint Propagation Expert System (COPES) Shell, developed initially on the Rome Lab BM/C3 study. Using a model of the network and several heuristics, the COPES shell was used to develop the Heuristic Adaptive Link Ordering (HALO) Algorithm to rank and order potential laser links according to probability of communication. A reduced set of links based on this ranking would then be used by a routing algorithm to select the next hop. This paper includes an overview of Constraint Propagation as an Artificial Intelligence technique and its embodiment in the COPES shell. It describes the design and implementation of both the simulation of the GPALS BP network and the HALO algorithm in COPES. This is described using a 59 Data Flow Diagram, State Transition Diagrams, and Structured English PDL. It describes a laser communications model and the heuristics involved in rank-ordering the potential communication links. The generation of simulation data is described along with its interface via COPES to the Harris developed View Net graphical tool for visual analysis of communications

  2. Eliminación de patógenos en biosólidos por estabilización alcalina Eliminating pathogens in biosolids by alkaline stabilization

    Directory of Open Access Journals (Sweden)

    Patricia Torres Lozada

    2009-07-01

    Full Text Available La Planta de Tratamiento de Aguas Residuales de Cañaveralejo -PTAR-C de Cali- Colombia, produce alrededor de 100 t/día de biosólidos que, aunque no tienen restricción por metales pesados, son clase B por el nivel de microorganismos patógenos y parásitos. En un diseño completamente al azar, conformado por seis tratamientos con su respectivo duplicado, se evaluó la estabilización alcalina con dosis del 9% peso a peso de cal viva e hidratada, aplicada a pilas de 0.5 t de biosólidos húmedos (66.5% y secos a temperatura ambiente (25 - 31°C durante 72 h (humedad 50.1%. Con la estabilización alcalina el pH aumentó a valores superiores a 12 unidades durante el tiempo suficiente para garantizar la reducción de patógenos y parásitos, alcanzando un material clase A; sin embargo, el biosólido seco facilitó la formación de grumos que dificultaron las labores de homogenización del sustrato con los alcalinizantes, factor indeseable para la eficiente reducción de patógenos.The Cañaveralejo wastewater treatment plant (PTAR-C based in Cali-Colombia, produces almost 100 t-day-1 of biosolids. Although do not have heavy metals restrictions, it is class B for high contents of pathogens microorganisms and parasites. The alkali stabilization was done with a 9% of dose (w/w of quicklime and hydrated lime applied to different 0.5 ton piles of wet biosolids (66.5% humidity and dry biosolids an environmental temperature (25-31°C for 72 hours (50.1% humidity. The experiment had a completely randomized design and it was composed by 6 treatments with their respective duplicated. With the alkali stabilization, the pH increments above 12 units during enough time to assure pathogens and parasites reduction in order to achieve a class A material level. On the other hand, the dry biosolids facilitate the conditions for lumps formation that reduce the homogenization of the substrate with the alkali material, which it is and undesirable factor for pathogen

  3. Structure-property investigations on a laser beam welded dissimilar joint of aluminium AA6056 and titanium Ti6Al4V for aeronautical applications. Part II: resistance to fatigue crack propagation and fracture

    Energy Technology Data Exchange (ETDEWEB)

    Horstmann, M.; Ventzke, V.; Petrovski, B.; Kocak, M. [GKSS Research Centre Geesthacht, Institute of Materials Research, Materials Mechanics, Geesthacht (Germany); Kocik, R.; Tempus, G. [AIRBUS Deutschland GmbH, Metal Technology, Bremen (Germany); Vaidya, W.V.

    2009-10-15

    Investigations were continued on the dissimilar laser beam welds of AA6056 and Ti6Al4V, fabricated by inserting Ti-sheet into the profiled Al-sheet and melting AA6056 alone. By using microstructure, hardness and strength as the criteria, sites exhibiting non-uniform microstructure and localized plastic deformation due to strength mismatch were investigated in two orientations: crack parallel to the weld and crack perpendicular to the weld for fatigue crack propagation and fracture toughness at room temperature. Effect of temper of AA6056 on these properties was studied for two conditions; welding in T4 followed by post weld heat treatment T6, and welding in T6 and naturally aged for a defined period. The orientation ''crack parallel to the weld'' was investigated in 3 locations on the side of AA6056: the interface and the two changeovers on the Al-side. Firstly, between the fusion zone and the heat affected zone (3 mm from the interface) and secondly, between (primary) heat affected zone and towards the base material (7 mm from the interface). Although brittle intermetallic TiAl{sub 3} had been formed at the interface, uncontrolled separation or debonding at the interface was not observed. Insofar the bond quality of the weld was good. However, the ranking of interface was the lowest since fatigue crack propagation was relatively faster than that in the fusion zone and heat affected zone, and fracture toughness was low. Therefore, unstable fatigue crack propagation is observed when the crack propagates perpendicular to the weld from AA6056 towards Ti6Al4V. The results have shown that the dissimilar joints exhibit improved performance when laser beam welded in the T6 condition. (Abstract Copyright [2009], Wiley Periodicals, Inc.) [German] Teil II: Widerstand gegen Ermuedungsrissausbreitung und Bruch Die Untersuchungen an der laserstrahlgeschweissten Mischverbindung aus AA6056 und Ti6Al4V wurden fortgesetzt. Fuer die Ermuedungsrissausbreitungs

  4. Propagation engineering in radio links design

    CERN Document Server

    Ghasemi, Abdollah; Ghasemi, Farshid

    2013-01-01

    Propagation Engineering in Radio Link Design covers the basic principles of radiowaves propagation in a practical manner.  This fundamental understanding enables the readers to design radio links efficiently. This book elaborates on new achievements as well as recently developed propagation models.  This is in addition to a comprehensive overview of fundamentals of propagation in various scenarios. It examines theoretical calculations, approaches and applied procedures needed for radio links design. The authors study and analysis of the main propagation phenomena and its mechanisms based on the recommendations of International Telecommunications Union, (ITU). The book has been organized in 9 chapters and examines the role of antennas and passive reflectors in radio services, propagation mechanisms related to radar, satellite, short distance, broadcasting and trans-horizon radio links, with two chapters devoted to radio noise and main  parameters of radio link design. The book presents some 278 illustration...

  5. Some properties of light propagation in relativity

    International Nuclear Information System (INIS)

    Bazanski, Stanislaw L.

    1998-01-01

    An outline of a formalism is proposed that describes relativistic effects associated with the propagation of light rays which after being initially split start to reconverge and intersect each other again. Beside a general geometric description that uses the approach of geometric optics, it has been shown how to compute both the difference of the proper times of arrivals of the two light beams to a measuring apparatus, as well as the frequency shifts of each of the beams taken separately. The formalism used here is applicable to both the special and the general theory of relativity, and it can be used equally well either when the light split is produced by a man-made optical device or when it is caused by the gravity field itself. The geometric description used in the formalism is independent of the physical origin of the frequency shift; of whether it is a Doppler, gravitational or cosmological frequency shift effect. Two simple examples of the application of the formalism have been worked out, which illustrate its results for families of inertial and noninertial observers respectively. Furthermore, a short description of a continuous version of the formalism has been presented in the last section of the article

  6. Numerical Investigation of Fracture Propagation in Geomaterials

    Science.gov (United States)

    Newell, P.; Borowski, E.; Major, J. R.; Eichhubl, P.

    2015-12-01

    Fracture in geomaterials is a critical behavior that affects the long-term structural response of geosystems. The processes involving fracture initiation and growth in rocks often span broad time scales and size scales, contributing to the complexity of these problems. To better understand fracture behavior, the authors propose an initial investigation comparing the fracture testing techniques of notched three-point bending (N3PB), short rod (SR), and double torsion (DT) on geomaterials using computational analysis. Linear softening cohesive fracture modeling (LCFM) was applied using ABAQUS to computationally simulate the three experimental set-ups. By applying material properties obtained experimentally, these simulations are intended to predict single-trace fracture growth. The advantages and limitations of the three testing techniques were considered for application to subcritical fracture propagation taking into account the accuracy of constraints, load applications, and modes of fracture. This work is supported as part of the Geomechanics of CO2 Reservoir Seals, a DOE-NETL funded under Award Number DE-FOA-0001037. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  7. Acoustic energy propagation around railways

    Science.gov (United States)

    Cizkova, Petra

    2017-09-01

    The article deals with the issues of acoustic energy propagation around railways. The research subject was noise emission spreading into the surroundings during the passage of trains over a directly travelled steel bridge construction. Noise emissions were measured using direct measurements in the field. The measurements were performed in two measurement profiles. The noise exposures A LAE measured near the steel bridge construction were compared against the noise exposures A LAE captured on an open track. From the difference of these data, the noise level of the steel bridge structure was determined. Part of the research was to evaluate the effect of the reconstruction of the railway track superstructure on the acoustic situation in the given section of the railway track. The article describes the methodology of measurements, including the processing and evaluation of measured data. The article points out the noise levels of the steel bridge construction and assesses changes in the acoustic situation after the reconstruction.

  8. Pulse Propagation on close conductors

    CERN Document Server

    Dieckmann, A

    2001-01-01

    The propagation and reflection of arbitrarily shaped pulses on non-dispersive parallel conductors of finite length with user defined cross section is simulated employing the discretized telegraph equation. The geometry of the system of conductors and the presence of dielectric material determine the capacities and inductances that enter the calculation. The values of these parameters are found using an iterative Laplace equation solving procedure and confirmed for certain calculable geometries including the line charge inside a box. The evolving pulses and the resulting crosstalk can be plotted at any instant and - in the Mathematica notebook version of this report - be looked at in an animation. As an example a differential pair of microstrips as used in the ATLAS vertex detector is analysed.

  9. IBEX - annular beam propagation experiment

    International Nuclear Information System (INIS)

    Mazarakis, M.G.; Miller, R.B.; Shope, S.L.; Poukey, J.W.; Ramirez, J.J.; Ekdahl, C.A.; Adler, R.J.

    1983-01-01

    IBEX is a 4-MV, 100-kA, 20-ns cylindrical isolated Blumlein accelerator. In the experiments reported here, the accelerator is fitted with a specially designed foilless diode which is completely immersed in a uniform magnetic field. Several diode geometries have been studied as a function of magnetic field strength. The beam propagates a distance of 50 cm (approx. 10 cyclotron wavelengths) in vacuum before either striking a beam stop or being extracted through a thin foil. The extracted beam was successfully transported 60 cm downstream into a drift pipe filled either with 80 or 640 torr air. The main objectives of this experiment were to establish the proper parameters for the most quiescent 4 MV, 20 to 40 kA annular beam, and to compare the results with available theory and numerical code simulations

  10. Front propagation in flipping processes

    International Nuclear Information System (INIS)

    Antal, T; Ben-Avraham, D; Ben-Naim, E; Krapivsky, P L

    2008-01-01

    We study a directed flipping process that underlies the performance of the random edge simplex algorithm. In this stochastic process, which takes place on a one-dimensional lattice whose sites may be either occupied or vacant, occupied sites become vacant at a constant rate and simultaneously cause all sites to the right to change their state. This random process exhibits rich phenomenology. First, there is a front, defined by the position of the leftmost occupied site, that propagates at a nontrivial velocity. Second, the front involves a depletion zone with an excess of vacant sites. The total excess Δ k increases logarithmically, Δ k ≅ ln k, with the distance k from the front. Third, the front exhibits ageing-young fronts are vigorous but old fronts are sluggish. We investigate these phenomena using a quasi-static approximation, direct solutions of small systems and numerical simulations

  11. Rapid Vegetative Propagation Method for Carob

    OpenAIRE

    Hamide GUBBUK; Esma GUNES; Tomas AYALA-SILVA; Sezai ERCISLI

    2011-01-01

    Most of fruit species are propagated by vegetative methods such as budding, grafting, cutting, suckering, layering etc. to avoid heterozygocity. Carob trees (Ceratonia siliqua L.) are of highly economical value and are among the most difficult to propagate fruit species. In the study, air-layering propagation method was investigated first time to compare wild and cultivated (�Sisam�) carob types. In the experiment, one year old carob limbs were air-layered on coco peat medium by wrapping with...

  12. Aspects of HF radio propagation

    Directory of Open Access Journals (Sweden)

    Stephane Saillant

    2009-06-01

    Full Text Available

    radio systems. From the point of view Working Group 2 of the COST 296 Action, interest lies with effects associated

    with propagation via the ionosphere of signals within the HF band. Several aspects are covered in this paper:

    a The directions of arrival and times of flight of signals received over a path oriented along the trough have

    been examined and several types of propagation effects identified. Of particular note, combining the HF observations

    with satellite measurements has identified the presence of irregularities within the floor of the trough that

    result in propagation displaced from the great circle direction. An understanding of the propagation effects that

    result in deviations of the signal path from the great circle direction are of particular relevance to the operation

    of HF radiolocation systems.

    b Inclusion of the results from the above mentioned measurements into a propagation model of the northerly

    ionosphere (i.e. those regions of the ionosphere located poleward of, and including, the mid-latitude trough

    and the use of this model to predict the coverage expected from transmitters where the signals impinge on the

    northerly ionosphere

  13. Perfiles de resistencia a antibióticos y metales pesados en Pseudomonas aeruginosa potencialmente patógenas aisladas de agua de uso agrícola

    Directory of Open Access Journals (Sweden)

    Oscar G. Gutiérrez Cárdenas

    2017-01-01

    Full Text Available El 70% de l agua a nivel mundial se destina principalmente para las actividades agrícolas. Sin embargo, debido al crecimiento descontrolado de los asentamientos urbanos se ha acentuado la escasez y contaminación de los cuerpos de agua superficiales, de tal forma que cada vez este líquido de buena calidad es más escaso para la agricultura. Uno de los pri n cipa les contaminantes son las bacterias potencialmente patógenas resistentes a los antibiót i cos. Pseudomonas aeruginosa es una bacteria que se encuentra normalmente en el agua y suelo, es patógeno de animales y plantas. Esta bacteria se ha considerado un fenóm eno de resistencia debido a la diversidad de mecanismos que posee, por lo cual representa un rie s go potencial para la p o blación. Método : Se colectaron muestras de agua de uso agrícola, a partir de las cuales se aislaron e identificaron a nivel bioquímico y molecular P. aeruginosa . En estas bacterias se determinó la distribución de 6 genes de virulencia por PCR. Mediante ensayos de difusión en disco y m i crodilución se analizó la resistencia a 20 antibióticos. Además mediante ensayos de microd i lución se dete rminó la resistencia a metales pesados. Resultados : Se identificaron a nivel bioquímico y molecular 46 aislados de P. aeruginosa, éstas son potencialmente patógenas ya que en ellas se detectó la presencia de los genes de virule n cia algD y toxA (100%, las B (97.8%, plcH (95.6%, plcN (91.3% y exoS (89.1%. Dichas bacterias presentaron altos índices de resistencia a ampicilina, ceftriaxona, cloranfen i col, cefalotina, cefotaxima, nitrofurantoína, kanamicina , estreptomicina y tetraciclina. De igual forma fue ron muy susceptibles a ceftazidima, gentamicina, imipenem, ticarcilina, a z treonam, levofloxacina, netilmicina y carbenicilina. Todas las bacterias fueron multirresiste n tes ya que toleraron entre 8 y 11 antibióticos. De acuerdo a los patrones de resistencia obse r vados, las bacterias se

  14. Escherichia coli O157:H7- patógeno alimentar emergente / Escherichia coli O157:H7 - emerging food pathogen

    Directory of Open Access Journals (Sweden)

    Cheila Minéia Daniel de Paula

    2014-11-01

    Full Text Available Segundo a Organização Mundial da Saúde, cerca de 2,2 milhões de pessoas morrem anualmente em função de doenças hídricas ou alimentares, a maioria dos quais são crianças. Estas doenças são causadas por patógenos já conhecidos, emergentes ou reemergentes, principalmente bactérias. A globalização tem contribuído na disseminação de patógenos de origem alimentar, aumentando o desafio relacionado à identificação da origem desses agentes e à elaboração de regulamentação e fiscalização adequadas. O cenário das Doenças Transmitidas por Alimentos (DTA muda constantemente e a prevalência de determinada doença varia de época para época, assim como os agentes etiológicos destas. Dentre os principais patógenos emergentes em nível mundial, E. coli O157:H7 tem ganhado grande destaque nos últimos 20 anos, devido à severidade de seus surtos. Até pouco tempo, o Brasil era considerado livre desse patógeno, porém a bibliografia científica e registros epidemiológicos demonstram o contrário. Em vista disso, o presente artigo objetiva realizar uma revisão integrativa da literatura, enfocando as características, os métodos de isolamento e detecção e os dados epidemiológicos da E. coli O157:H7 no Brasil e no mundo. =============================================== According to the World Health Organization, about 2.2 million people, most of whom are children, die each year due to water and foodborne illnesses. These illnesses are caused by known, emerging, or reemerging pathogens, mainly bacteria. Globalization has contributed to the spread of foodborne pathogens, increasing the challenge of identifying the origin of these agents and of developing appropriate regulation and monitoring. The scenario of Foodborne Illnesses (FI constantly changes and the prevalence of a particular illnesses as well as its etiological agents, vary from season to season. Among the major emerging pathogens at a global level, E. coli O157:H7

  15. 125I-BH-8-MeO-N-PAT, a new ligand for studying 5-HT1A receptors in the central nervous system

    International Nuclear Information System (INIS)

    Ponchant, M.; Beaucourt, J.P.; Vanhove, A.

    1988-01-01

    Specific radioactive ligands are needed for studying the pharmacological properties and the regional distribution of the different classes of 5-HT 1 receptors within the central nervous system. We describe here the synthesis and some characteristics of the first iodinated specific ligand of 5-HT 1A receptors. Like its parent compound, the agonist 8-hydroxy-2-(di-n-propylamino)tetralin or 8-OH-DPAT, [ 125 I]-BH-8-MeO-N-PAT, exhibits a high affinity and excellent selectivity for 5-HT 1A sites. Its high specific radioactivity makes this ligand a useful tool for studying 5-HT 1A receptors in membranes and sections of the rat brain [fr

  16. A theory for the propagation of changes to confinement

    Energy Technology Data Exchange (ETDEWEB)

    Christiansen, J P [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking

    1994-07-01

    A drift kinetic fluid model has been developed. It shows that diamagnetic drifts do not contribute to transport of plasma and energy (no entropy generation). Application of the model to a simplified description of plasma turbulence shows that disturbances, such as heat-cold pulses, L to H transitions, all can propagate with the fluid advective drift velocity irrespective of the nature of these disturbances. 6 refs.

  17. A theory for the propagation of changes to confinement

    International Nuclear Information System (INIS)

    Christiansen, J.P.

    1994-01-01

    A drift kinetic fluid model has been developed. It shows that diamagnetic drifts do not contribute to transport of plasma and energy (no entropy generation). Application of the model to a simplified description of plasma turbulence shows that disturbances, such as heat-cold pulses, L to H transitions, all can propagate with the fluid advective drift velocity irrespective of the nature of these disturbances. 6 refs

  18. Statistics of optical vortex wander on propagation through atmospheric turbulence.

    Science.gov (United States)

    Gu, Yalong

    2013-04-01

    The transverse position of an optical vortex on propagation through atmospheric turbulence is studied. The probability density of the optical vortex position on a transverse plane in the atmosphere is formulated in weak turbulence by using the Born approximation. With these formulas, the effect of aperture averaging on topological charge detection is investigated. These results provide quantitative guidelines for the design of an optimal detector of topological charge, which has potential application in optical vortex communication systems.

  19. Wave propagation in fluids models and numerical techniques

    CERN Document Server

    Guinot, Vincent

    2012-01-01

    This second edition with four additional chapters presents the physical principles and solution techniques for transient propagation in fluid mechanics and hydraulics. The application domains vary including contaminant transport with or without sorption, the motion of immiscible hydrocarbons in aquifers, pipe transients, open channel and shallow water flow, and compressible gas dynamics. The mathematical formulation is covered from the angle of conservation laws, with an emphasis on multidimensional problems and discontinuous flows, such as steep fronts and shock waves. Finite

  20. Neural network construction via back-propagation

    International Nuclear Information System (INIS)

    Burwick, T.T.

    1994-06-01

    A method is presented that combines back-propagation with multi-layer neural network construction. Back-propagation is used not only to adjust the weights but also the signal functions. Going from one network to an equivalent one that has additional linear units, the non-linearity of these units and thus their effective presence is then introduced via back-propagation (weight-splitting). The back-propagated error causes the network to include new units in order to minimize the error function. We also show how this formalism allows to escape local minima

  1. Terrestrial propagation of long electromagnetic waves

    CERN Document Server

    Galejs, Janis; Fock, V A

    2013-01-01

    Terrestrial Propagation of Long Electromagnetic Waves deals with the propagation of long electromagnetic waves confined principally to the shell between the earth and the ionosphere, known as the terrestrial waveguide. The discussion is limited to steady-state solutions in a waveguide that is uniform in the direction of propagation. Wave propagation is characterized almost exclusively by mode theory. The mathematics are developed only for sources at the ground surface or within the waveguide, including artificial sources as well as lightning discharges. This volume is comprised of nine chapte

  2. Fatigue crack propagation behavior under creep conditions

    International Nuclear Information System (INIS)

    Ohji, Kiyotsugu; Kubo, Shiro

    1991-01-01

    The crack propagation behavior of the SUS 304 stainless steel under creep-fatigue conditions was reviewed. Cracks propagated either in purely time-dependent mode or in purely cycle-dependent mode, depending on loading conditions. The time-dependent crack propagation rate was correlated with modified J-integral J * and the cycle-dependent crack propagation rate was correlated with J-integral range ΔJ f . Threshold was observed in the cycle-dependent crack propagation, and below this threshold the time-dependent crack propagation appeared. The crack propagation rates were uniquely characterized by taking the effective values of J * and ΔJ f , when crack closure was observed. Change in crack propagation mode occurred reversibly and was predicted by the competitive damage model. The threshold disappeared and the cycle-dependent crack propagation continued in a subthreshold region under variable amplitude conditions, where the threshold was interposed between the maximum and minimum ΔJ f . (orig.)

  3. Propagation of cortical spreading depression into the hippocampus: The role of the entorhinal cortex.

    Science.gov (United States)

    Martens-Mantai, Tanja; Speckmann, Erwin-Josef; Gorji, Ali

    2014-07-22

    Propagation of cortical spreading depression (CSD) to the subcortical structures could be the underlying mechanism of some neurological deficits in migraine with aura. The entorhinal cortex (EC) as a gray matter bridge between the neocortex and subcortical regions plays an important role in this propagation. In vitro combined neocortex-hippocampus brain slices were used to study the propagation pattern of CSD between the neocortex and the hippocampus. The effects of different compounds as well as tetanic electrical stimulations in the EC on propagation of CSD to the hippocampus were investigated. Repetitive induction of CSD by KCl injection in the somatosensory cortex enhanced the probability of CSD entrance to the hippocampus via EC. Local application of AMPA receptor blocker CNQX and cannabinoid receptor agonist WIN 55212-2 in EC facilitated the propagation of CSD to the hippocampus, whereas application of NMDA receptor blocker APV and GABA A receptor blocker bicuculline in this region reduced the probability of CSD penetration to the hippocampus. Application of tetanic stimulation in EC also facilitated the propagation of CSD entrance to the hippocampus. Our data suggest the importance of synaptic plasticity of EC in filtering the propagation of CSD into subcortical structures and possibly the occurrence of concomitant neurological deficits. Synapse, 2014. © 2014 Wiley Periodicals, Inc. © 2014 Wiley Periodicals, Inc.

  4. An integrated process analytical technology (PAT) approach to monitoring the effect of supercooling on lyophilization product and process parameters of model monoclonal antibody formulations.

    Science.gov (United States)

    Awotwe Otoo, David; Agarabi, Cyrus; Khan, Mansoor A

    2014-07-01

    The aim of the present study was to apply an integrated process analytical technology (PAT) approach to control and monitor the effect of the degree of supercooling on critical process and product parameters of a lyophilization cycle. Two concentrations of a mAb formulation were used as models for lyophilization. ControLyo™ technology was applied to control the onset of ice nucleation, whereas tunable diode laser absorption spectroscopy (TDLAS) was utilized as a noninvasive tool for the inline monitoring of the water vapor concentration and vapor flow velocity in the spool during primary drying. The instantaneous measurements were then used to determine the effect of the degree of supercooling on critical process and product parameters. Controlled nucleation resulted in uniform nucleation at lower degrees of supercooling for both formulations, higher sublimation rates, lower mass transfer resistance, lower product temperatures at the sublimation interface, and shorter primary drying times compared with the conventional shelf-ramped freezing. Controlled nucleation also resulted in lyophilized cakes with more elegant and porous structure with no visible collapse or shrinkage, lower specific surface area, and shorter reconstitution times compared with the uncontrolled nucleation. Uncontrolled nucleation however resulted in lyophilized cakes with relatively lower residual moisture contents compared with controlled nucleation. TDLAS proved to be an efficient tool to determine the endpoint of primary drying. There was good agreement between data obtained from TDLAS-based measurements and SMART™ technology. ControLyo™ technology and TDLAS showed great potential as PAT tools to achieve enhanced process monitoring and control during lyophilization cycles. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  5. Avaliação da estabilidade e da qualidade do patê de presunto, adicionado de globina bovina e de caseinato de sódio, como agente emulsionante Stability and quality of ham paté added of bovine globin and sodium caseinate as emulsifiers

    Directory of Open Access Journals (Sweden)

    Janaína Guernica Silva

    2003-04-01

    Full Text Available Este trabalho foi conduzido para avaliar o efeito da incorporação das globinas bovina extraída pelo método da acetona acidificada (GT e pelo da carboximetilcelulose (GCMC e do caseinato de sódio (CA sobre a composição química e as qualidades microbiológica e sensorial do patê de presunto. Foi, ainda, avaliada a estabilidade do produto durante os 45 dias de estocagem sob refrigeração, por meio das determinações de pH e do grau de oxidação lipídica. De acordo com os resultados obtidos, pôde-se verificar que a adição dessas proteínas elevou o teor protéico das amostras analisadas. Além disso, observou-se que apenas a GT provocou uma queda do pH e uma elevação de substâncias reativas ao ácido 2-tiobarbitúrico (thiobarbiuric acid reactive substances - TBARS. Com relação à qualidade microbiológica dos produtos, não foram observadas alterações após a incorporação das proteínas e, pela análise sensorial, foram identificadas diferenças significativas entre as duas formulações de patê avaliadas (PCA e PGCMC.This study evaluated the effect of the use of bovine globin extracted by acidified acetone method (GT, bovine globin extracted by carboxymethyl cellulose method (GCMC and sodium caseinate (CA on the chemical composition and on microbiological and sensorial qualities of the ham paté. Also, the stability of this meat product was studied during the storage for 45 days under refrigeration, on the pH and on the lipid oxidation measurements. An increase of the protein contents was observed in all samples. Moreover, only the incorporation of GT produced a significant decrease of pH and an increasing of thiobarbiuric acid reactive substances (TBARS values during storage. No microbial effects were observed while some significant differences were observed between PCA and PGCMC added patés.

  6. Interplay of hot electrons from localized and propagating plasmons.

    Science.gov (United States)

    Hoang, Chung V; Hayashi, Koki; Ito, Yasuo; Gorai, Naoki; Allison, Giles; Shi, Xu; Sun, Quan; Cheng, Zhenzhou; Ueno, Kosei; Goda, Keisuke; Misawa, Hiroaki

    2017-10-03

    Plasmon-induced hot-electron generation has recently received considerable interest and has been studied to develop novel applications in optoelectronics, photovoltaics and green chemistry. Such hot electrons are typically generated from either localized plasmons in metal nanoparticles or propagating plasmons in patterned metal nanostructures. Here we simultaneously generate these heterogeneous plasmon-induced hot electrons and exploit their cooperative interplay in a single metal-semiconductor device to demonstrate, as an example, wavelength-controlled polarity-switchable photoconductivity. Specifically, the dual-plasmon device produces a net photocurrent whose polarity is determined by the balance in population and directionality between the hot electrons from localized and propagating plasmons. The current responsivity and polarity-switching wavelength of the device can be varied over the entire visible spectrum by tailoring the hot-electron interplay in various ways. This phenomenon may provide flexibility to manipulate the electrical output from light-matter interaction and offer opportunities for biosensors, long-distance communications, and photoconversion applications.Plasmon-induced hot electrons have potential applications spanning photodetection and photocatalysis. Here, Hoang et al. study the interplay between hot electrons generated by localized and propagating plasmons, and demonstrate wavelength-controlled polarity-switchable photoconductivity.

  7. Propagation and dispersion of shock waves in magnetoelastic materials

    Science.gov (United States)

    Crum, R. S.; Domann, J. P.; Carman, G. P.; Gupta, V.

    2017-12-01

    Previous studies examining the response of magnetoelastic materials to shock waves have predominantly focused on applications involving pulsed power generation, with limited attention given to the actual wave propagation characteristics. This study provides detailed magnetic and mechanical measurements of magnetoelastic shock wave propagation and dispersion. Laser generated rarefacted shock waves exceeding 3 GPa with rise times of 10 ns were introduced to samples of the magnetoelastic material Galfenol. The resulting mechanical measurements reveal the evolution of the shock into a compressive acoustic front with lateral release waves. Importantly, the wave continues to disperse even after it has decayed into an acoustic wave, due in large part to magnetoelastic coupling. The magnetic data reveal predominantly shear wave mediated magnetoelastic coupling, and were also used to noninvasively measure the wave speed. The external magnetic field controlled a 30% increase in wave propagation speed, attributed to a 70% increase in average stiffness. Finally, magnetic signals propagating along the sample over 20× faster than the mechanical wave were measured, indicating these materials can act as passive antennas that transmit information in response to mechanical stimuli.

  8. Regeneration de Pat Barker (1991 : la gestion des maux/mots de la Grande Guerre par l’institution psychiatrique

    Directory of Open Access Journals (Sweden)

    Isabelle Gérardin

    2011-04-01

    Full Text Available Cet article se propose d’étudier une œuvre publiée en 1991 par la romancière anglaise Pat Barker : Regeneration. Ce roman, qui a pour toile de fond la Grande Guerre, ne dépeint ni combats ni scènes de la vie des tranchées. Barker préfère représenter toute la dimension agonistique de ce conflit mondial à travers la question de la prise en charge des traumatismes de guerre des soldats par l’institution psychiatrique. Ces traumatismes, ayant diverses manifestations psychosomatiques, témoignent d’une forte tension entre une profonde aversion de l’individu pour l’extrême violence des affrontements et un appel à se conformer à une certaine culture de guerre collective fondée sur un idéal fort de virilité martiale et patriotique. Face à ces traumatismes, ainsi que Pat Barker le met en lumière, la psychiatrie de guerre se révèle souvent fort ambiguë. En effet, l’institution psychiatrique œuvre en continuité avec l’institution militaire, désirant imposer un contrôle sur les âmes autant que sur les corps. Regeneration nous invite donc à lire combien les maux/mots de la Grande Guerre ont eu grand peine à se faire entendre.This article deals with a novel, entitled Regeneration, published in 1991 by the English female author Pat Barker. This novel, although set against the backdrop of World War One, depicts neither battles nor scenes of everyday life in the trenches. Instead, the agonistic dimension of this world conflict is tackled by Pat Barker through the prism of the way the psychiatric institution dealt with war traumas endured by soldiers, traumas of the body and of the mind. These traumas, causing a variety of psychosomatic symptoms, reveal a powerful tension between a deep individual aversion to the extreme violence of combat and an appeal to conform to some collective culture of war rooted in a strong ideal of soldierly and patriotic manliness. Wartime psychiatry, as Barker highlights, often turns out to

  9. CaMKII-MEDIATED PHOSPHORYLATION OF THE BOMBYX MORI LIPID STORAGE DROPLET PROTEIN-1 (BmLsd1), AN INSECT PAT FAMILY PROTEIN, IS ESSENTIAL FOR SILKMOTH SEX PHEROMONE BIOSYNTHESIS

    Science.gov (United States)

    The structurally-related members of the PAT family of proteins, which are so name based on similarity amongst perilipin, adipophilin/adipocyte differentiation-related protein (ADRP), and tail-interacting protein of 47 kilodaltons (TIP47), are cytoplasmic lipid droplet (LD)-associated proteins charac...

  10. Hormone signaling linked to silkmoth sex pheromone biosynthesis involves Ca2+/calmodulin-dependent protein kinase II-mediated phosphorylation of the insect PAT family protein Bombyx mori lipid storage droplet protein-1(BmLsd)

    Science.gov (United States)

    The structurally-related members of the PAT family of proteins, which are so name based on similarity amongst perilipin, adipophilin/adipocyte differentiation-related protein (ADRP), and tail-interacting protein of 47 kilodaltons (TIP47), are cytoplasmic lipid droplet (LD)-associated proteins charac...

  11. Changes of seasonally dry forest in the Colombian Patía Valley during the early and middle Holocene and the development of a dry climatic record for the northernmost Andes

    NARCIS (Netherlands)

    González-Carranza, Z.; Berrío, J.C.; Hooghiemstra, H.; Duivenvoorden, J.F.; Behling, H.

    2008-01-01

    A 450 cm long sediment core was collected from a swamp in the dry forest ecosystem of the Patía Valley in Colombia (02°02′ N, 77° W at 750 m elevation). This core (Potrerillo-2) was analysed using pollen, lithostratigraphy and radiocarbon dates and was correlated with an already existing dataset

  12. Simultaneous enrichment of cysteine-containing peptides and phosphopeptides using a cysteine-specific phosphonate adaptable tag (CysPAT) in combination with titanium dioxide (TiO2) chromatography

    DEFF Research Database (Denmark)

    Huang, Honggang; Pedersen, Martin Haar; Ibañez-Vea, Maria

    2016-01-01

    to selectively label cysteine-containing peptides (Cys peptides) followed by their enrichment with titanium dioxide (TiO2) and subsequent mass spectrometric analysis. The CysPAT strategy was developed using a synthetic peptide, a standard protein and subsequently the strategy was applied to protein lysates from...

  13. In Vitro Mass Propagation of Cymbopogon citratus Stapf., a Medicinal Gramineae.

    Science.gov (United States)

    Quiala, Elisa; Barbón, Raúl; Capote, Alina; Pérez, Naivy; Jiménez, Elio

    2016-01-01

    Cymbopogon citratus (D.C.) Stapf. is a medicinal plant source of lemon grass oils with multiple uses in the pharmaceutical and food industry. Conventional propagation in semisolid culture medium has become a fast tool for mass propagation of lemon grass, but the production cost must be lower. A solution could be the application of in vitro propagation methods based on liquid culture advantages and automation. This chapter provides two efficient protocols for in vitro propagation via organogenesis and somatic embryogenesis of this medicinal plant. Firstly, we report the production of shoots using a temporary immersion system (TIS). Secondly, a protocol for somatic embryogenesis using semisolid culture for callus formation and multiplication, and liquid culture in a rotatory shaker and conventional bioreactors for the maintenance of embryogenic culture, is described. Well-developed plants can be achieved from both protocols. Here we provide a fast and efficient technology for mass propagation of this medicinal plant taking the advantage of liquid culture and automation.

  14. Simulation and Prediction of Weather Radar Clutter Using a Wave Propagator on High Resolution NWP Data

    DEFF Research Database (Denmark)

    Benzon, Hans-Henrik; Bovith, Thomas

    2008-01-01

    for prediction of this type of weather radar clutter is presented. The method uses a wave propagator to identify areas of potential non-standard propagation. The wave propagator uses a three dimensional refractivity field derived from the geophysical parameters: temperature, humidity, and pressure obtained from......Weather radars are essential sensors for observation of precipitation in the troposphere and play a major part in weather forecasting and hydrological modelling. Clutter caused by non-standard wave propagation is a common problem in weather radar applications, and in this paper a method...... a high-resolution Numerical Weather Prediction (NWP) model. The wave propagator is based on the parabolic equation approximation to the electromagnetic wave equation. The parabolic equation is solved using the well-known Fourier split-step method. Finally, the radar clutter prediction technique is used...

  15. In-medium covariant propagator of baryons under a strong magnetic field: Effect of the intrinsic magnetic moments

    Energy Technology Data Exchange (ETDEWEB)

    Aguirre, R.M.; Paoli, A.L. de [Universidad Nacional de La Plata, and IFLP, Departamento de Fisica, Facultad de Ciencias Exactas, La Plata (Argentina)

    2016-11-15

    We obtain the covariant propagator at finite temperature for interacting baryons immersed in a strong magnetic field. The effect of the intrinsic magnetic moments on the Green function are fully taken into account. We make an expansion in terms of eigenfunctions of a Dirac field, which leads us to a compact form of its propagator. We present some simple applications of these propagators, where the statistical averages of nuclear currents and energy density are evaluated. (orig.)

  16. Propagated failure analysis for non-repairable systems considering both global and selective effects

    International Nuclear Information System (INIS)

    Wang Chaonan; Xing Liudong; Levitin, Gregory

    2012-01-01

    This paper proposes an algorithm for the reliability analysis of non-repairable binary systems subject to competing failure propagation and failure isolation events with both global and selective failure effects. A propagated failure that originates from a system component causes extensive damage to the rest of the system. Global effect happens when the propagated failure causes the entire system to fail; whereas selective effect happens when the propagated failure causes only failure of a subset of system components. In both cases, the failure propagation that originates from some system components (referred to as dependent components) can be isolated because of functional dependence between the dependent components and a component that prevents the failure propagation (trigger components) when the failure of the trigger component happens before the occurrence of the propagated failure. Most existing studies focus on the analysis of propagated failures with global effect. However, in many cases, propagated failures affect only a subset of system components not the entire system. Existing approaches for analyzing propagated failures with selective effect are limited to series-parallel systems. This paper proposes a combinatorial method for the propagated failure analysis considering both global and selective effects as well as the competition with the failure isolation in the time domain. The proposed method is not limited to series-parallel systems and has no limitation on the type of time-to-failure distributions for the system components. The method is verified using the Markov-based method. An example of computer memory systems is analyzed to demonstrate the application of the proposed method.

  17. Content Propagation in Online Social Networks

    NARCIS (Netherlands)

    Blenn, N.

    2014-01-01

    This thesis presents methods and techniques to analyze content propagation within online social networks (OSNs) using a graph theoretical approach. Important factors and different techniques to analyze and describe content propagation, starting from the smallest entity in a network, representing a

  18. Propagation of microwaves in pulsar magnetospheres

    Energy Technology Data Exchange (ETDEWEB)

    Bodo, G; Ferrari, A [Turin Univ. (Italy). Ist. di Fisica Generale; Consiglio Nazionale delle Ricerche, Turin (Italy). Lab. di Cosmo-Geofisica); Massaglia, S [Turin Univ. (Italy). Ist. di Fisica Generale; Cambridge Univ. (UK). Inst. of Astronomy)

    1981-12-01

    We discuss the dispersion relation of linearly-polarized waves, propagating along a strong background magnetic field embedded in an electron-positron plasma. The results are then applied to the study of the propagation conditions of coherent curvature radio radiation inside neutron stars magnetospheres, as produced by electric discharges following current pulsar models.

  19. Wave propagation in thermoelastic saturated porous medium

    Indian Academy of Sciences (India)

    the existence and propagation of four waves in the medium. Three of the waves are ... predicted infinite speed for propagation of ther- mal signals. Lord and ..... saturated reservoir rock (North-sea Sandstone) is chosen for the numerical model ...

  20. In vitro propagation of Irvingia gabonensis

    African Journals Online (AJOL)

    GREGO

    2007-04-16

    Apr 16, 2007 ... Full-grown plantlets were obtained and work is in progress on mass propagation. ... subsequent mass propagation to produce seedlings for farmers, and to improve food security and ... Shooting and rooting were observed, and full grown plantlets were obtained. ¼ MS +0.2 mg KIN. +0.1 mg NAA. Rooting ...

  1. Uncertainty Propagation in an Ecosystem Nutrient Budget.

    Science.gov (United States)

    New aspects and advancements in classical uncertainty propagation methods were used to develop a nutrient budget with associated error for a northern Gulf of Mexico coastal embayment. Uncertainty was calculated for budget terms by propagating the standard error and degrees of fr...

  2. Canada Basin Acoustic Propagation Experiment (CANAPE)

    Science.gov (United States)

    2015-09-30

    acoustic communications, acoustic navigation, or acoustic remote sensing of the ocean interior . RELATED PROJECTS The 2015 CANAPE pilot study was a...1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Canada Basin Acoustic Propagation Experiment (CANAPE...ocean structure. Changes in sea ice and the water column affect both acoustic propagation and ambient noise. This implies that what was learned

  3. Diagnostics for the ATA beam propagation experiments

    International Nuclear Information System (INIS)

    Fessenden, T.J.; Atchison, W.L.; Barletta, W.A.

    1981-11-01

    This report contains a discussion of the diagnostics required for the beam propagation experiment to be done with the ATA accelerator. Included are a list of the diagnostics needed; a description of the ATA experimental environment; the status of beam diagnostics available at Livermore including recent developments, and a prioritized list of accelerator and propagation diagnostics under consideration or in various stages of development

  4. Unirradiated cladding rip-propagation tests

    International Nuclear Information System (INIS)

    Hu, W.L.; Hunter, C.W.

    1981-04-01

    The size of cladding rips which develop when a fuel pin fails can affect the subassembly cooling and determine how rapidly fuel escapes from the pin. The object of the Cladding Rip Propagation Test (CRPT) was to quantify the failure development of cladding so that a more realistic fuel pin failure modeling may be performed. The test results for unirradiated 20% CS 316 stainless steel cladding show significantly different rip propagation behavior at different temperatures. At room temperature, the rip growth is stable as the rip extension increases monotonically with the applied deformation. At 500 0 C, the rip propagation becomes unstable after a short period of stable rip propagation. The rapid propagation rate is approximately 200 m/s, and the critical rip length is 9 mm. At test temperatures above 850 0 C, the cladding exhibits very high failure resistances, and failure occurs by multiple cracking at high cladding deformation. 13 figures

  5. In vitro propagation of jojoba.

    Science.gov (United States)

    Llorente, Berta E; Apóstolo, Nancy M

    2013-01-01

    Jojoba (Simmondsia chinensis (Link) Schn.) is a nontraditional crop in arid and semi-arid areas. Vegetative propagation can be achieved by layering, grafting, or rooting semi-hardwood cuttings, but the highest number of possible propagules is limited by the size of the plants and time of the year. Micropropagation is highly recommended strategy for obtaining jojoba elite clones. For culture initiation, single-node explants are cultivated on Murashige and Skoog medium (MS) supplemented with Gamborg's vitamins (B5), 11.1 μM BA (N(6)-benzyl-adenine), 0.5 μM IBA (indole-3-butyric acid), and 1.4 μM GA(3) (gibberellic acid). Internodal and apical cuttings proliferate on MS medium containing B5 vitamins and 4.4 μM BA. Rooting is achieved on MS medium (half strength mineral salt) amended with B5 vitamins and 14.7 μM IBA during 7 days and transferred to develop in auxin-free rooting medium. Plantlets are acclimatized using a graduated humidity regime on soil: peat: perlite (5:1:1) substrate. This micropagation protocol produces large numbers of uniform plants from selected genotypes of jojoba.

  6. Biomass plug development and propagation in porous media.

    Science.gov (United States)

    Stewart, T L; Fogler, H S

    2001-02-05

    Exopolymer-producing bacteria can be used to modify soil profiles for enhanced oil recovery or bioremediation. Understanding the mechanisms associated with biomass plug development and propagation is needed for successful application of this technology. These mechanisms were determined from packed-bed and micromodel experiments that simulate plugging in porous media. Leuconostoc mesenteroides was used, because production of dextran, a water-insoluble exopolymer, can be controlled by using different carbon sources. As dextran was produced, the pressure drop across the porous media increased and began to oscillate. Three pressure phases were identified under exopolymer-producing conditions: the exopolymer-induction phase, the plugging phase, and the plug-propagation phase. The exopolymer-induction phase extended from the time that exopolymer-producing conditions were induced until there was a measurable increase in pressure drop across the porous media. The plugging phase extended from the first increase in pressure drop until a maximum pressure drop was reached. Changes in pressure drop in these two phases were directly related to biomass distribution. Specifically, flow channels within the porous media filled with biomass creating a plugged region where convective flow occurred only in water channels within the biofilm. These water channels were more restrictive to flow causing the pressure drop to increase. At a maximum pressure drop across the porous media, the biomass yielded much like a Bingham plastic, and a flow channel was formed. This behavior marked the onset of the plug-propagation phase which was characterized by sequential development and breakthrough of biomass plugs. This development and breakthrough propagated the biomass plug in the direction of nutrient flow. The dominant mechanism associated with all three phases of plugging in porous media was exopolymer production; yield stress is an additional mechanism in the plug-propagation phase. Copyright

  7. Wave propagation on a plasma media

    International Nuclear Information System (INIS)

    Torres-Silva, H.; Villarroel-Gonzalez, C.; Reggiani, N.; Sakanaka, P.H.

    1995-01-01

    Chiral-media and ferrite media have been studied over the last decade for many applications. Chiral-media have been examined as coating for reducing radar cross section, for antennas and arrays, for antenna radomes in waveguides and for microstrip substrate. Here, we examine a chiral-plasma medium, where the plasma part of the composite medium is non-reciprocal due to the external magnetic field, to find the general dispersion relation giving the ω against K behavior, vector phasor Helmholtz based equations are derived. We determine the modal eigenvalue properties in the chiral-plasma medium, which is doubly anisotropic. For the case of waves which propagate parallel to the magnetic field is a cold magnetized chiro-plasma. We compare our results with the typical results obtained for a cold plasma. Also we obtain the chiral-Faraday rotation which can be compared with the typical Faraday rotation for a pair of right-and left-handed circularly polarized waves. (author). 5 refs., 2 figs

  8. Mathematical problems in wave propagation theory

    CERN Document Server

    1970-01-01

    The papers comprising this collection are directly or indirectly related to an important branch of mathematical physics - the mathematical theory of wave propagation and diffraction. The paper by V. M. Babich is concerned with the application of the parabolic-equation method (of Academician V. A. Fok and M. A, Leontovich) to the problem of the asymptotic behavior of eigenfunc­ tions concentrated in a neighborhood of a closed geodesie in a Riemannian space. The techniques used in this paper have been föund useful in solving certain problems in the theory of open resonators. The topic of G. P. Astrakhantsev's paper is similar to that of the paper by V. M. Babich. Here also the parabolic-equation method is used to find the asymptotic solution of the elasticity equations which describes Love waves concentrated in a neighborhood of some surface ray. The paper of T. F. Pankratova is concerned with finding the asymptotic behavior of th~ eigenfunc­ tions of the Laplace operator from the exact solution for the surf...

  9. Learning topic models by belief propagation.

    Science.gov (United States)

    Zeng, Jia; Cheung, William K; Liu, Jiming

    2013-05-01

    Latent Dirichlet allocation (LDA) is an important hierarchical Bayesian model for probabilistic topic modeling, which attracts worldwide interest and touches on many important applications in text mining, computer vision and computational biology. This paper represents the collapsed LDA as a factor graph, which enables the classic loopy belief propagation (BP) algorithm for approximate inference and parameter estimation. Although two commonly used approximate inference methods, such as variational Bayes (VB) and collapsed Gibbs sampling (GS), have gained great success in learning LDA, the proposed BP is competitive in both speed and accuracy, as validated by encouraging experimental results on four large-scale document datasets. Furthermore, the BP algorithm has the potential to become a generic scheme for learning variants of LDA-based topic models in the collapsed space. To this end, we show how to learn two typical variants of LDA-based topic models, such as author-topic models (ATM) and relational topic models (RTM), using BP based on the factor graph representations.

  10. Synchronization with propagation - The functional differential equations

    Science.gov (United States)

    Rǎsvan, Vladimir

    2016-06-01

    The structure represented by one or several oscillators couple to a one-dimensional transmission environment (e.g. a vibrating string in the mechanical case or a lossless transmission line in the electrical case) turned to be attractive for the research in the field of complex structures and/or complex behavior. This is due to the fact that such a structure represents some generalization of various interconnection modes with lumped parameters for the oscillators. On the other hand the lossless and distortionless propagation along transmission lines has generated several research in electrical, thermal, hydro and control engineering leading to the association of some functional differential equations to the basic initial boundary value problems. The present research is performed at the crossroad of the aforementioned directions. We shall associate to the starting models some functional differential equations - in most cases of neutral type - and make use of the general theorems for existence and stability of forced oscillations for functional differential equations. The challenges introduced by the analyzed problems for the general theory are emphasized, together with the implication of the results for various applications.

  11. Nonlinear magnetoacoustic wave propagation with chemical reactions

    Science.gov (United States)

    Margulies, Timothy Scott

    2002-11-01

    The magnetoacoustic problem with an application to sound wave propagation through electrically conducting fluids such as the ocean in the Earth's magnetic field, liquid metals, or plasmas has been addressed taking into account several simultaneous chemical reactions. Using continuum balance equations for the total mass, linear momentum, energy; as well as Maxwell's electrodynamic equations, a nonlinear beam equation has been developed to generalize the Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation for a fluid with linear viscosity but nonlinear and diffraction effects. Thermodynamic parameters are used and not tailored to only an adiabatic fluid case. The chemical kinetic equations build on a relaxing media approach presented, for example, by K. Naugolnukh and L. Ostrovsky [Nonlinear Wave Processes in Acoustics (Cambridge Univ. Press, Cambridge, 1998)] for a linearized single reaction and thermodynamic pressure equation of state. Approximations for large and small relaxation times and for magnetohydrodynamic parameters [Korsunskii, Sov. Phys. Acoust. 36 (1990)] are examined. Additionally, Cattaneo's equation for heat conduction and its generalization for a memory process rather than a Fourier's law are taken into account. It was introduced for the heat flux depends on the temperature gradient at an earlier time to generate heat pulses of finite speed.

  12. A finite element beam propagation method for simulation of liquid crystal devices.

    Science.gov (United States)

    Vanbrabant, Pieter J M; Beeckman, Jeroen; Neyts, Kristiaan; James, Richard; Fernandez, F Anibal

    2009-06-22

    An efficient full-vectorial finite element beam propagation method is presented that uses higher order vector elements to calculate the wide angle propagation of an optical field through inhomogeneous, anisotropic optical materials such as liquid crystals. The full dielectric permittivity tensor is considered in solving Maxwell's equations. The wide applicability of the method is illustrated with different examples: the propagation of a laser beam in a uniaxial medium, the tunability of a directional coupler based on liquid crystals and the near-field diffraction of a plane wave in a structure containing micrometer scale variations in the transverse refractive index, similar to the pixels of a spatial light modulator.

  13. Self-Propagating Reactive Fronts in Compacts of Multilayered Particles

    International Nuclear Information System (INIS)

    Sraj, I.; Vohra, M.; Alawieh, L.; Weihs, T.P.; Knio, O.M.

    2013-01-01

    Reactive multilayered foils in the form of thin films have gained interest in various applications such as joining, welding, and ignition. Typically, thin film multilayers support self-propagating reaction fronts with speeds ranging from 1 to 20 m/s. In some applications, however, reaction fronts with much smaller velocities are required. This recently motivated Fritz et al. (2011) to fabricate compacts of regular sized/shaped multilayered particles and demonstrate self-sustained reaction fronts having much smaller velocities than thin films with similar layering. In this work, we develop a simplified numerical model to simulate the self-propagation of reactive fronts in an idealized compact, comprising identical Ni/Al multilayered particles in thermal contact. The evolution of the reaction in the compact is simulated using a two-dimensional transient model, based on a reduced description of mixing, heat release, and thermal transport. Computed results reveal that an advancing reaction front can be substantially delayed as it crosses from one particle to a neighboring particle, which results in a reduced mean propagation velocity. A quantitative analysis is thus conducted on the dependence of these phenomena on the contact area between the particles, the thermal contact resistance, and the arrangement of the multilayered particles.

  14. Soot Formation in Freely-Propagating Laminar Premixed Flames

    Science.gov (United States)

    Lin, K.-C.; Hassan, M. I.; Faeth, G. M.

    1997-01-01

    Soot formation within hydrocarbon-fueled flames is an important unresolved problem of combustion science. Thus, the present study is considering soot formation in freely-propagating laminar premixed flames, exploiting the microgravity environment to simplify measurements at the high-pressure conditions of interest for many practical applications. The findings of the investigation are relevant to reducing emissions of soot and continuum radiation from combustion processes, to improving terrestrial and spacecraft fire safety, and to developing methods of computational combustion, among others. Laminar premixed flames are attractive for studying soot formation because they are simple one-dimensional flows that are computationally tractable for detailed numerical simulations. Nevertheless, studying soot-containing burner-stabilized laminar premixed flames is problematical: spatial resolution and residence times are limited at the pressures of interest for practical applications, flame structure is sensitive to minor burner construction details so that experimental reproducibility is not very good, consistent burner behavior over the lengthy test programs needed to measure soot formation properties is hard to achieve, and burners have poor durability. Fortunately, many of these problems are mitigated for soot-containing, freely-propagating laminar premixed flames. The present investigation seeks to extend work in this laboratory for various soot processes in flames by observing soot formation in freely-propagating laminar premixed flames. Measurements are being made at both Normal Gravity (NG) and MicroGravity (MG), using a short-drop free-fall facility to provide MG conditions.

  15. Self-Propagating Reactive Fronts in Compacts of Multilayered Particles

    Directory of Open Access Journals (Sweden)

    Ihab Sraj

    2013-01-01

    Full Text Available Reactive multilayered foils in the form of thin films have gained interest in various applications such as joining, welding, and ignition. Typically, thin film multilayers support self-propagating reaction fronts with speeds ranging from 1 to 20 m/s. In some applications, however, reaction fronts with much smaller velocities are required. This recently motivated Fritz et al. (2011 to fabricate compacts of regular sized/shaped multilayered particles and demonstrate self-sustained reaction fronts having much smaller velocities than thin films with similar layering. In this work, we develop a simplified numerical model to simulate the self-propagation of reactive fronts in an idealized compact, comprising identical Ni/Al multilayered particles in thermal contact. The evolution of the reaction in the compact is simulated using a two-dimensional transient model, based on a reduced description of mixing, heat release, and thermal transport. Computed results reveal that an advancing reaction front can be substantially delayed as it crosses from one particle to a neighboring particle, which results in a reduced mean propagation velocity. A quantitative analysis is thus conducted on the dependence of these phenomena on the contact area between the particles, the thermal contact resistance, and the arrangement of the multilayered particles.

  16. Ocorrência de patógenos em cultivos de melancia e abóbora no sertão da Paraíba

    Directory of Open Access Journals (Sweden)

    M. G. F. O. Soares

    2016-01-01

    Full Text Available Por constituírem uma importante fonte de alimento, plantações de melancia e abóbora são comumente cultivadas no sertão paraibano, porém pouco se sabe sobre a ocorrência de patógenos causadores de doenças, os quais limitam a sua produtividade e renda aos produtores. Visando obter informações sobre a ocorrência dos patógenos virais e fúngicos em cultivos de abóbora e melancia situados em municípios produtores no sertão da Paraíba, amostras coletadas com sintomas de mosaico e deformação foliar, típicos de doenças virais foram analisadas pela técnica sorológica “enzime linked immuno sorbentassay” (Elisa indireto para Papaya ring spot virus, type watermelon (PRSV-W, Watermelon mosaic virus (WMV, Zucchini yellow mosaic virus (ZYMV e Cucumber mosaic virus (CMV. O teste de dupla difusão em Agar foi utilizado para verificar a presença de Squash mosaic virus (SqMV. Em contrapartida, amostras coletadas com sintomas de doenças fúngicas foram analisadas pelo isolamento do patógeno e visualização de suas características morfológicas em microscópio óptico. Em abóbora, houve prevalência dos vírus ZYMV e PRSV-W em infecções simples e mistas, e maior incidência dos fungos Cladosporium spp., e Alternaria spp. Em melancia detectou-se infecção simples e mistas das espécies PRSV-W, WMV e ZYMV, e maior freqüência de Fusarium spp. e Alternaria spp.. Não foram detectados os vírus CMV e SqMV. Os resultados obtidos revelam a ocorrência de vários patógenos fúngicos e viróticos em cultivos de abóbora e melancia situados no sertão da Paraíba e ressaltam a importância da utilização de estratégias de manejo que reduzem os danos ocasionados por esses patógenos.Occurrence of pathogens in watermelon and pumpkin crops in the State of ParaibaAbstract: By constitute an important food source, watermelon and pumpkin plantations are commonly grown on Paraíba backlands, but little is known about the occurrence of disease

  17. Propagation of hypergeometric Gaussian beams in strongly nonlocal nonlinear media

    Science.gov (United States)

    Tang, Bin; Bian, Lirong; Zhou, Xin; Chen, Kai

    2018-01-01

    Optical vortex beams have attracted lots of interest due to its potential application in image processing, optical trapping and optical communications, etc. In this work, we theoretically and numerically investigated the propagation properties of hypergeometric Gaussian (HyGG) beams in strongly nonlocal nonlinear media. Based on the Snyder-Mitchell model, analytical expressions for propagation of the HyGG beams in strongly nonlocal nonlinear media were obtained. The influence of input power and optical parameters on the evolutions of the beam width and radius of curvature is illustrated, respectively. The results show that the beam width and radius of curvature of the HyGG beams remain invariant, like a soliton when the input power is equal to the critical power. Otherwise, it varies periodically like a breather, which is the result of competition between the beam diffraction and nonlinearity of the medium.

  18. Propagation and storing of light in optically modified atomic media

    International Nuclear Information System (INIS)

    Zaremba, Jaroslaw

    2010-01-01

    Coherent interactions of laser light with atomic ensembles allow one to modify dispersive properties of a medium and lead to new optical phenomena. Studies of the controlled light propagation and storing in such media have recently become a dynamically developing field of research motivated both by the fundamental character of the processes and by potential applications. This article briefly reviews basic theoretical approach to the dynamics of the propagation of laser pulses in optically modified media. The method and the physical processes are discussed that allow one to slow down the group velocity of laser pulse to zero (stopping of light), to transfer the state of a light pulse to atomic coherences and to restore the pulse. The interpretation of these phenomena in the formalism of dark-state polaritons is presented. Examples of possible coherent manipulations on a stored light are also discussed.

  19. Propagation and storing of light in optically modified atomic media

    Energy Technology Data Exchange (ETDEWEB)

    Zaremba, Jaroslaw, E-mail: zaremba@fizyka.iomk.p [Institute of Physics Nicolaus Copernicus University ul. Grudziadzka 5/7 87 100 Torun (Poland)

    2010-03-01

    Coherent interactions of laser light with atomic ensembles allow one to modify dispersive properties of a medium and lead to new optical phenomena. Studies of the controlled light propagation and storing in such media have recently become a dynamically developing field of research motivated both by the fundamental character of the processes and by potential applications. This article briefly reviews basic theoretical approach to the dynamics of the propagation of laser pulses in optically modified media. The method and the physical processes are discussed that allow one to slow down the group velocity of laser pulse to zero (stopping of light), to transfer the state of a light pulse to atomic coherences and to restore the pulse. The interpretation of these phenomena in the formalism of dark-state polaritons is presented. Examples of possible coherent manipulations on a stored light are also discussed.

  20. Multiplexed Holograms by Surface Plasmon Propagation and Polarized Scattering.

    Science.gov (United States)

    Chen, Ji; Li, Tao; Wang, Shuming; Zhu, Shining

    2017-08-09

    Thanks to the superiority in controlling the optical wave fronts, plasmonic nanostructures have led to various striking applications, among which metasurface holograms have been well developed and endowed with strong multiplexing capability. Here, we report a new design of multiplexed plasmonic hologram, which allows for reconstruction of multiple holographic images in free space by scatterings of surface plasmon polariton (SPP) waves in different propagation directions. Besides, the scattered polarization states can be further modulated by arranging the orientations of nanoscatterers. By incorporation of the SPP propagation and polarized scattering, a 4-fold hologram with low crosstalk is successfully demonstrated, which breaks the limitation of only two orthogonal states in conventional polarization multiplexers. Moreover, our design using the near-field SPP as reference wave holds the advantage for compact integration. This holographic approach is expected to inspire new photonic designs with enhanced information capacity and integratability.

  1. Excitation of coherent propagating spin waves by pure spin currents.

    Science.gov (United States)

    Demidov, Vladislav E; Urazhdin, Sergei; Liu, Ronghua; Divinskiy, Boris; Telegin, Andrey; Demokritov, Sergej O

    2016-01-28

    Utilization of pure spin currents not accompanied by the flow of electrical charge provides unprecedented opportunities for the emerging technologies based on the electron's spin degree of freedom, such as spintronics and magnonics. It was recently shown that pure spin currents can be used to excite coherent magnetization dynamics in magnetic nanostructures. However, because of the intrinsic nonlinear self-localization effects, magnetic auto-oscillations in the demonstrated devices were spatially confined, preventing their applications as sources of propagating spin waves in magnonic circuits using these waves as signal carriers. Here, we experimentally demonstrate efficient excitation and directional propagation of coherent spin waves generated by pure spin current. We show that this can be achieved by using the nonlocal spin injection mechanism, which enables flexible design of magnetic nanosystems and allows one to efficiently control their dynamic characteristics.

  2. Quasi-Airy beams along tunable propagation trajectories and directions.

    Science.gov (United States)

    Qian, Yixian; Zhang, Site

    2016-05-02

    We present a theoretical and experimental exhibit that accelerates quasi-Airy beams propagating along arbitrarily appointed parabolic trajectories and directions in free space. We also demonstrate that such quasi-Airy beams can be generated by a tunable phase pattern, where two disturbance factors are introduced. The topological structures of quasi-Airy beams are readily manipulated with tunable phase patterns. Quasi-Airy beams still possess the characteristics of non-diffraction, self-healing to some extent, although they are not the solutions for paraxial wave equation. The experiments show the results are consistent with theoretical predictions. It is believed that the property of propagation along arbitrarily desired parabolic trajectories will provide a broad application in trapping atom and living cell manipulation.

  3. Ultrashort pulse-propagation effects in a semiconductor optical amplifier: Microscopic theory and experiment

    DEFF Research Database (Denmark)

    Hughes, S.; Borri, P.; Knorr, A.

    2001-01-01

    We present microscopic modeling and experimental measurements of femtosecond-pulse interactions in a semiconductor optical amplifier. Two novel nonlinear propagation effects are demonstrated: pulse breakup in the gain regime and pulse compression in the transparency regime. These propagation phen...... phenomena highlight the microscopic origin and important role of adiabatic following in semiconductor optical amplifiers. Fundamental light-matter interactions are discussed in detail and possible applications are highlighted....

  4. PROPAGATION OF NEW BLACKBERRY CULTIVARS FOR PRODUCING CERTIFIED PROPAGATION MATERIAL

    Directory of Open Access Journals (Sweden)

    Valentina Isac

    2014-12-01

    Full Text Available The purpose of this research was to study the behaviour of two new Romanian thorn blackberry cultivars DAR 24 and DAR 8 in process of micropropagation, compared with Darrow cultivar usually commercially micropropagated in our laboratory. Due to several drawbacks of the conventional propagation of Rubus, the efficiency of micropropagation was tested in order to obtain high quality planting material and to introduce rapidly these new cultivars in a certification program. Thorn blackberry cultivars DAR 8 and DAR 24 with resistance to winter colds was successfully micropropagated. Blackberry plants were found without virus infection after biological and ELISA tests. Axillary buds from the branches in full growth were used as the initial explants. After four weeks of growth, aseptic cultures was established on MS basal mineral salts, LS vitamins with 0.3 mg/l BAP, 0.1mg/l GA3 and 0.001mg/l NAA. The rate of successfully established cultures was on average 65.11%. Good proliferation of the regenerated shoots was obtained on the same medium composition used for initiation phase, whereas medium MS with mineral salts reduced to ½ and LS vitamins with 0.1 mg/l IBA and 0.1 mg/l GA3 was used in the rooting phase. Dar 24 and Dar 8 cultivars responded by good rates of micropropagation on medium culture B as compared to control Darrow cultivar, even if the obtained shoots length was lower than on medium A. The statistical analysis reveled that the highest MR (20.66 plantlets/explant was obtained for Dar 24. In this case the length of shoots was 1.92 cm. The highest rooting percentages (over 85% were obtained with shoots multiplied on medium B. High quality of rooted plants induced a high percentage of acclimatization of cultivar Dar 8, 86.36% under mist system in green house whereas the percentage of acclimatization of cultivar Dar 24 was lower, 51.85%.

  5. The accuracy of dynamic attitude propagation

    Science.gov (United States)

    Harvie, E.; Chu, D.; Woodard, M.

    1990-01-01

    Propagating attitude by integrating Euler's equation for rigid body motion has long been suggested for the Earth Radiation Budget Satellite (ERBS) but until now has not been implemented. Because of limited Sun visibility, propagation is necessary for yaw determination. With the deterioration of the gyros, dynamic propagation has become more attractive. Angular rates are derived from integrating Euler's equation with a stepsize of 1 second, using torques computed from telemetered control system data. The environmental torque model was quite basic. It included gravity gradient and unshadowed aerodynamic torques. Knowledge of control torques is critical to the accuracy of dynamic modeling. Due to their coarseness and sparsity, control actuator telemetry were smoothed before integration. The dynamic model was incorporated into existing ERBS attitude determination software. Modeled rates were then used for attitude propagation in the standard ERBS fine-attitude algorithm. In spite of the simplicity of the approach, the dynamically propagated attitude matched the attitude propagated with good gyros well for roll and yaw but diverged up to 3 degrees for pitch because of the very low resolution in pitch momentum wheel telemetry. When control anomalies significantly perturb the nominal attitude, the effect of telemetry granularity is reduced and the dynamically propagated attitudes are accurate on all three axes.

  6. Failure propagation tests and analysis at PNC

    International Nuclear Information System (INIS)

    Tanabe, H.; Miyake, O.; Daigo, Y.; Sato, M.

    1984-01-01

    Failure propagation tests have been conducted using the Large Leak Sodium Water Reaction Test Rig (SWAT-1) and the Steam Generator Safety Test Facility (SWAT-3) at PNC in order to establish the safety design of the LMFBR prototype Monju steam generators. Test objectives are to provide data for selecting a design basis leak (DBL), data on the time history of failure propagations, data on the mechanism of the failures, and data on re-use of tubes in the steam generators that have suffered leaks. Eighteen fundamental tests have been performed in an intermediate leak region using the SWAT-1 test rig, and ten failure propagation tests have been conducted in the region from a small leak to a large leak using the SWAT-3 test facility. From the test results it was concluded that a dominant mechanism was tube wastage, and it took more than one minute until each failure propagation occurred. Also, the total leak rate in full sequence simulation tests including a water dump was far less than that of one double-ended-guillotine (DEG) failure. Using such experimental data, a computer code, LEAP (Leak Enlargement and Propagation), has been developed for the purpose of estimating the possible maximum leak rate due to failure propagation. This paper describes the results of the failure propagation tests and the model structure and validation studies of the LEAP code. (author)

  7. Pole solutions for flame front propagation

    CERN Document Server

    Kupervasser, Oleg

    2015-01-01

    This book deals with solving mathematically the unsteady flame propagation equations. New original mathematical methods for solving complex non-linear equations and investigating their properties are presented. Pole solutions for flame front propagation are developed. Premixed flames and filtration combustion have remarkable properties: the complex nonlinear integro-differential equations for these problems have exact analytical solutions described by the motion of poles in a complex plane. Instead of complex equations, a finite set of ordinary differential equations is applied. These solutions help to investigate analytically and numerically properties of the flame front propagation equations.

  8. Inward propagating chemical waves in Taylor vortices.

    Science.gov (United States)

    Thompson, Barnaby W; Novak, Jan; Wilson, Mark C T; Britton, Melanie M; Taylor, Annette F

    2010-04-01

    Advection-reaction-diffusion (ARD) waves in the Belousov-Zhabotinsky reaction in steady Taylor-Couette vortices have been visualized using magnetic-resonance imaging and simulated using an adapted Oregonator model. We show how propagating wave behavior depends on the ratio of advective, chemical and diffusive time scales. In simulations, inward propagating spiral flamelets are observed at high Damköhler number (Da). At low Da, the reaction distributes itself over several vortices and then propagates inwards as contracting ring pulses--also observed experimentally.

  9. Propagation considerations in land mobile satellite transmission

    Science.gov (United States)

    Vogel, W. J.; Smith, E. K.

    1985-01-01

    It appears likely that the Land Mobile Satellite Services (LMSS) will be authorized by the FCC for operation in the 800 to 900 MHz (UHF) and possibly near 1500 MHz (L-band). Propagation problems are clearly an important factor in the effectiveness of this service, but useful measurements are few, and produced contradictory interpretations. A first order overview of existing measurements is presented with particular attention to the first two NASA balloon to mobile vehicle propagation experiments. Some physical insight into the interpretation of propagation effects in LMSS transmissions is provided.

  10. Crack Propagation by Finite Element Method

    Directory of Open Access Journals (Sweden)

    Luiz Carlos H. Ricardo

    2018-01-01

    Full Text Available Crack propagation simulation began with the development of the finite element method; the analyses were conducted to obtain a basic understanding of the crack growth. Today structural and materials engineers develop structures and materials properties using this technique. The aim of this paper is to verify the effect of different crack propagation rates in determination of crack opening and closing stress of an ASTM specimen under a standard suspension spectrum loading from FDandE SAE Keyhole Specimen Test Load Histories by finite element analysis. To understand the crack propagation processes under variable amplitude loading, retardation effects are observed

  11. A Survey of Symplectic and Collocation Integration Methods for Orbit Propagation

    Science.gov (United States)

    Jones, Brandon A.; Anderson, Rodney L.

    2012-01-01

    Demands on numerical integration algorithms for astrodynamics applications continue to increase. Common methods, like explicit Runge-Kutta, meet the orbit propagation needs of most scenarios, but more specialized scenarios require new techniques to meet both computational efficiency and accuracy needs. This paper provides an extensive survey on the application of symplectic and collocation methods to astrodynamics. Both of these methods benefit from relatively recent theoretical developments, which improve their applicability to artificial satellite orbit propagation. This paper also details their implementation, with several tests demonstrating their advantages and disadvantages.

  12. Wave propagation of spectral energy content in a granular chain

    NARCIS (Netherlands)

    Shrivastava, Rohit Kumar; Luding, Stefan

    2017-01-01

    A mechanical wave is propagation of vibration with transfer of energy and momentum. Understanding the spectral energy characteristics of a propagating wave through disordered granular media can assist in understanding the overall properties of wave propagation through inhomogeneous materials like

  13. Modelling of Fracture Initiation, Propagation and Creep of a KBS-3V and KBS-3H Repository in Sparsely Fractured Rock with Application to the Design at Forsmark Candidate Site

    International Nuclear Information System (INIS)

    Backers, Tobias; Stephansson, Ove

    2008-01-01

    influences the stability of the KBS-3 repository. With an acting swelling pressure no additional fracturing may be expected due to the ice load. If the swelling pressure is reduced for whatever reason, only the KBS-3H concept with the deposition hole axis parallel SH remained stable. Neighbouring excavations at spacing of 6m, as is currently planned by SKB, do not influence each other and therefore do not introduce additional risk for fracturing. It is concluded that the KBS-3H concept with the deposition hole axis parallel SH is the most favourable concept assuming rock properties and stress state according to SDM 1.2 at Forsmark. The impact of the stress changes due to excavation, swelling pressure and temperature are predicted to be minimal on this layout. Repository deposition holes at a depth of -450m are most favourable. In case of KBS-3 concept with deposition holes in a rock mass with discrete fracture network DFN according to SDM 1.2 at Forsmark the following conclusions are drawn: (i) In some regions of the fractured rock mass the original fracture network is not much affected by the excavation of the deposition holes, in other regions the fractures are significantly propagated and sometimes also leading to a connection between neighbouring deposition holes. (j) Due to presence of the pre-existing fractures, the initiation of new fractures in the vicinity of the deposition holes is reduced. (k) For some configurations of deposition holes and DFN, pre-existing fractures are propagating due to the increased stress field around the excavations that leads to interconnected fractures linking up neighbouring deposition holes. These connected fractures may act as potential pathways for fluid flow and transport, not only between the deposition holes, but also between deposition holes and the deposition tunnel. Time-dependent fracture growth is of minor importance at relevant in-situ stresses, swelling pressures and temperature conditions. The fracturing in case of the KBS

  14. Coupled seismic and electromagnetic wave propagation

    NARCIS (Netherlands)

    Schakel, M.D.

    2011-01-01

    Coupled seismic and electromagnetic wave propagation is studied theoretically and experimentally. This coupling arises because of the electrochemical double layer, which exists along the solid-grain/fluid-electrolyte boundaries of porous media. Within the double layer, charge is redistributed,

  15. A solid state lightning propagation speed sensor

    Science.gov (United States)

    Mach, Douglas M.; Rust, W. David

    1989-01-01

    A device to measure the propagation speeds of cloud-to-ground lightning has been developed. The lightning propagation speed (LPS) device consists of eight solid state silicon photodetectors mounted behind precision horizontal slits in the focal plane of a 50-mm lens on a 35-mm camera. Although the LPS device produces results similar to those obtained from a streaking camera, the LPS device has the advantages of smaller size, lower cost, mobile use, and easier data collection and analysis. The maximum accuracy for the LPS is 0.2 microsec, compared with about 0.8 microsecs for the streaking camera. It is found that the return stroke propagation speed for triggered lightning is different than that for natural lightning if measurements are taken over channel segments less than 500 m. It is suggested that there are no significant differences between the propagation speeds of positive and negative flashes. Also, differences between natural and triggered dart leaders are discussed.

  16. Universal self-similarity of propagating populations.

    Science.gov (United States)

    Eliazar, Iddo; Klafter, Joseph

    2010-07-01

    This paper explores the universal self-similarity of propagating populations. The following general propagation model is considered: particles are randomly emitted from the origin of a d-dimensional Euclidean space and propagate randomly and independently of each other in space; all particles share a statistically common--yet arbitrary--motion pattern; each particle has its own random propagation parameters--emission epoch, motion frequency, and motion amplitude. The universally self-similar statistics of the particles' displacements and first passage times (FPTs) are analyzed: statistics which are invariant with respect to the details of the displacement and FPT measurements and with respect to the particles' underlying motion pattern. Analysis concludes that the universally self-similar statistics are governed by Poisson processes with power-law intensities and by the Fréchet and Weibull extreme-value laws.

  17. Universal self-similarity of propagating populations

    Science.gov (United States)

    Eliazar, Iddo; Klafter, Joseph

    2010-07-01

    This paper explores the universal self-similarity of propagating populations. The following general propagation model is considered: particles are randomly emitted from the origin of a d -dimensional Euclidean space and propagate randomly and independently of each other in space; all particles share a statistically common—yet arbitrary—motion pattern; each particle has its own random propagation parameters—emission epoch, motion frequency, and motion amplitude. The universally self-similar statistics of the particles’ displacements and first passage times (FPTs) are analyzed: statistics which are invariant with respect to the details of the displacement and FPT measurements and with respect to the particles’ underlying motion pattern. Analysis concludes that the universally self-similar statistics are governed by Poisson processes with power-law intensities and by the Fréchet and Weibull extreme-value laws.

  18. Propagating semantic information in biochemical network models

    Directory of Open Access Journals (Sweden)

    Schulz Marvin

    2012-01-01

    Full Text Available Abstract Background To enable automatic searches, alignments, and model combination, the elements of systems biology models need to be compared and matched across models. Elements can be identified by machine-readable biological annotations, but assigning such annotations and matching non-annotated elements is tedious work and calls for automation. Results A new method called "semantic propagation" allows the comparison of model elements based not only on their own annotations, but also on annotations of surrounding elements in the network. One may either propagate feature vectors, describing the annotations of individual elements, or quantitative similarities between elements from different models. Based on semantic propagation, we align partially annotated models and find annotations for non-annotated model elements. Conclusions Semantic propagation and model alignment are included in the open-source library semanticSBML, available on sourceforge. Online services for model alignment and for annotation prediction can be used at http://www.semanticsbml.org.

  19. In vitro propagation of Paphiopedilum orchids.

    Science.gov (United States)

    Zeng, Songjun; Huang, Weichang; Wu, Kunlin; Zhang, Jianxia; da Silva, Jaime A Teixeira; Duan, Jun

    2016-01-01

    Paphiopedilum is one of the most popular and rare orchid genera. Members of the genus are sold and exhibited as pot plants and cut flowers. Wild populations of Paphiopedilum are under the threat of extinction due to over-collection and loss of suitable habitats. A reduction in their commercial value through large-scale propagation in vitro is an option to reduce pressure from illegal collection, to attempt to meet commercial needs and to re-establish threatened species back into the wild. Although they are commercially propagated via asymbiotic seed germination, Paphiopedilum are considered to be difficult to propagate in vitro, especially by plant regeneration from tissue culture. This review aims to cover the most important aspects and to provide an up-to-date research progress on in vitro propagation of Paphiopedilum and to emphasize the importance of further improving tissue culture protocols for ex vitro-derived explants.

  20. The ghost propagator in Coulomb gauge

    International Nuclear Information System (INIS)

    Watson, P.; Reinhardt, H.

    2011-01-01

    We present results for a numerical study of the ghost propagator in Coulomb gauge whereby lattice results for the spatial gluon propagator are used as input to solving the ghost Dyson-Schwinger equation. We show that in order to solve completely, the ghost equation must be supplemented by a boundary condition (the value of the inverse ghost propagator dressing function at zero momentum) which determines if the solution is critical (zero value for the boundary condition) or subcritical (finite value). The various solutions exhibit a characteristic behavior where all curves follow the same (critical) solution when going from high to low momenta until 'forced' to freeze out in the infrared to the value of the boundary condition. The boundary condition can be interpreted in terms of the Gribov gauge-fixing ambiguity; we also demonstrate that this is not connected to the renormalization. Further, the connection to the temporal gluon propagator and the infrared slavery picture of confinement is discussed.