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Sample records for field optimization procedure

  1. Optimization and field trial of nuclear medicine procedure for the detection of congenital hypothyroidism in a developing country

    International Nuclear Information System (INIS)

    Arnaldo Foradori, C.

    1987-08-01

    The optimization of the method for screening of neonatal hypothyroidism was done on the basis of local preparation of the necessary reagents like anti T4 rabbit antibody, radioactive tracer and goat antirabbit second antibody with the elimination of commercially available reagents kits. The blood sampling was performed using absorbing paper and T4 concentration was checked. The selection of T4 RIA was due to the robustness of the method and its easy reproducibility in comparison with TSH-RIA. In a group of 2000 newborns in Chile, three cases with neonatal hypothyroidism were found. One of them died within 72 hours because of multiple congenital defects while the two others with high TSH and low T4 are under current L-thyroxine treatment. The results obtained show the frequence of 3 cases of neonatal hypothyroidism out of 2000 newborns. This result is similar to results published in other Latin American countries, but higher than in Europe and USA. 14 refs, figs and tabs

  2. Efficient Reanalysis Procedures in Structural Topology Optimization

    DEFF Research Database (Denmark)

    Amir, Oded

    This thesis examines efficient solution procedures for the structural analysis problem within topology optimization. The research is motivated by the observation that when the nested approach to structural optimization is applied, most of the computational effort is invested in repeated solutions...... on approximate reanalysis. For cases where memory limitations require the utilization of iterative equation solvers, we suggest efficient procedures based on alternative termination criteria for such solvers. These approaches are tested on two- and three-dimensional topology optimization problems including...

  3. Procedure and methodology of Radiation Protection optimization

    International Nuclear Information System (INIS)

    Wang Hengde

    1995-01-01

    Optimization of Radiation Protection is one of the most important principles in the system of radiation protection. The paper introduces the basic principles of radiation protection optimization in general, and the procedure of implementing radiation protection optimization and methods of selecting the optimized radiation protection option in details, in accordance with ICRP 55. Finally, some economic concepts relating to estimation of costs are discussed briefly

  4. Optimization of well field management

    DEFF Research Database (Denmark)

    Hansen, Annette Kirstine

    Groundwater is a limited but important resource for fresh water supply. Differ- ent conflicting objectives are important when operating a well field. This study investigates how the management of a well field can be improved with respect to different objectives simultaneously. A framework...... for optimizing well field man- agement using multi-objective optimization is developed. The optimization uses the Strength Pareto Evolutionary Algorithm 2 (SPEA2) to find the Pareto front be- tween the conflicting objectives. The Pareto front is a set of non-inferior optimal points and provides an important tool...... for the decision-makers. The optimization framework is tested on two case studies. Both abstract around 20,000 cubic meter of water per day, but are otherwise rather different. The first case study concerns the management of Hardhof waterworks, Switzer- land, where artificial infiltration of river water...

  5. A convenient procedure for magnetic field homogeneity evaluation

    International Nuclear Information System (INIS)

    Teles, J; Garrido, C E; Tannus, A

    2004-01-01

    In many areas of research that utilize magnetic fields in their studies, it is important to obtain fields with a spatial distribution as homogeneous as possible. A procedure usually utilized to evaluate and to optimize field homogeneity is the expansion of the measured field in spherical harmonic components. In addition to the methods proposed in the literature, we present a more convenient procedure for evaluation of field homogeneity inside a spherical volume. The procedure uses the orthogonality property of the spherical harmonics to find the field variance. It is shown that the total field variance is equal to the sum of the individual variances of each field component in the spherical harmonic expansion. Besides the advantages of the linear behaviour of the individual variances, there is the fact that the field variance and standard deviation are the best parameters to achieve global homogeneity field information

  6. Aerial photogrammetry procedure optimized for micro uav

    Directory of Open Access Journals (Sweden)

    T. Anai

    2014-06-01

    Full Text Available This paper proposes the automatic aerial photogrammetry procedure optimized for Micro UAV that has ability of autonomous flight. The most important goal of our proposed method is the reducing the processing cost for fully automatic reconstruction of DSM from a large amount of image obtained from Micro UAV. For this goal, we have developed automatic corresponding point generation procedure using feature point tracking algorithm considering position and attitude information, which obtained from onboard GPS-IMU integrated on Micro UAV. In addition, we have developed the automatic exterior orientation and registration procedure from the automatic generated corresponding points on each image and position and attitude information from Micro UAV. Moreover, in order to reconstruct precise DSM, we have developed the area base matching process which considering edge information. In this paper, we describe processing flow of our automatic aerial photogrammetry. Moreover, the accuracy assessment is also described. Furthermore, some application of automatic reconstruction of DSM will be desired.

  7. Procedural Optimization Models for Multiobjective Flexible JSSP

    Directory of Open Access Journals (Sweden)

    Elena Simona NICOARA

    2013-01-01

    Full Text Available The most challenging issues related to manufacturing efficiency occur if the jobs to be sched-uled are structurally different, if these jobs allow flexible routings on the equipments and mul-tiple objectives are required. This framework, called Multi-objective Flexible Job Shop Scheduling Problems (MOFJSSP, applicable to many real processes, has been less reported in the literature than the JSSP framework, which has been extensively formalized, modeled and analyzed from many perspectives. The MOFJSSP lie, as many other NP-hard problems, in a tedious place where the vast optimization theory meets the real world context. The paper brings to discussion the most optimization models suited to MOFJSSP and analyzes in detail the genetic algorithms and agent-based models as the most appropriate procedural models.

  8. A surrogate based multistage-multilevel optimization procedure for multidisciplinary design optimization

    NARCIS (Netherlands)

    Yao, W.; Chen, X.; Ouyang, Q.; Van Tooren, M.

    2011-01-01

    Optimization procedure is one of the key techniques to address the computational and organizational complexities of multidisciplinary design optimization (MDO). Motivated by the idea of synthetically exploiting the advantage of multiple existing optimization procedures and meanwhile complying with

  9. Optimization procedures in mammography: First results

    International Nuclear Information System (INIS)

    Espana Lopez, M. L.; Marcos de Paz, L.; Martin Rincon, C.; Jerez Sainz, I.; Lopez Franco, M. P.

    2001-01-01

    Optimization procedures in mammography using equipment with a unique target/filter combination can be carried out through such diverse factors as target optical density, technique factors for exposure, screen film combination or processing cycle, in order to obtain an image adequate for the diagnosis with an acceptable risk benefit balance. Diverse studies show an increase in the Standardised Detection Rate of invasive carcinomas with an increase in the optical density among others factors. In our hospital an optimisation process has been established, and as previous step, the target optical density has been increased up to 1,4 DO. The aim of this paper is to value the impact of optical density variation as much in the quality of image as in the entrance surface dose and the average dose to the glandular tissue, comparing them with the results obtained in a previous study. The study has been carried out in a sample of 106 patients, with an average age of 53,4 years, considering 212 clinical images corresponding to the two projections of a same breast with an average compressed thickness of 4,86 cm. An increase of 16,6% on the entrance surface dose and 18% on the average dose to the glandular tissue has been recorded. All the clinical images has been evaluated for the physician as adequate for diagnosis. (Author) 16 refs

  10. Lagrangian procedures for higher order field equations

    International Nuclear Information System (INIS)

    Bollini, C.G.

    1987-01-01

    A Lagrangian procedure for a pedagogical way is presented for the treatment of higher order field equations. The energy-momentum tensor and the conserved density current are built. In particular the case in which the derivatives appear only in the invariant D'Alembertian operator is discussed. Some examples are discussed. The fields are quantized and the corresponding Hamilonian which is shown not to be positive defructed. Rules are given to write the causal propagators. (author) [pt

  11. Lagrangian procedures for higher order field equations

    International Nuclear Information System (INIS)

    Bollini, C.G.; Giambiagi, J.J.

    1986-01-01

    We present in a pedagogical way a Lagrangian procedure for the treatment of higher order field equations. We build the energy-momentum tensor and the conserved density current. In particular we discuss the case in which the derivatives appear only in the invariant D'Alembertian operator. We discuss some examples. We quantize the fields and construct the corresponding Hamiltonian which is shown not to be positive definite. We give the rules for the causal propagators. (Author) [pt

  12. A surrogate based multistage-multilevel optimization procedure for multidisciplinary design optimization

    OpenAIRE

    Yao, W.; Chen, X.; Ouyang, Q.; Van Tooren, M.

    2011-01-01

    Optimization procedure is one of the key techniques to address the computational and organizational complexities of multidisciplinary design optimization (MDO). Motivated by the idea of synthetically exploiting the advantage of multiple existing optimization procedures and meanwhile complying with the general process of satellite system design optimization in conceptual design phase, a multistage-multilevel MDO procedure is proposed in this paper by integrating multiple-discipline-feasible (M...

  13. Optimization of somatic embryogenesis procedure for commercial ...

    African Journals Online (AJOL)

    The first objective of this study was to assess and optimize somatic embryo production in a genetically diverse range of cacao genotypes. The primary and secondary somatic embryogenesis response of eight promising cacao clones and a positive control was evaluated using modified versions of standard protocols.

  14. Analysis and optimization of blood-testing procedures.

    NARCIS (Netherlands)

    Bar-Lev, S.K.; Boxma, O.J.; Perry, D.; Vastazos, L.P.

    2017-01-01

    This paper is devoted to the performance analysis and optimization of blood testing procedures. We present a queueing model of two queues in series, representing the two stages of a blood-testing procedure. Service (testing) in stage 1 is performed in batches, whereas it is done individually in

  15. A new approach of optimization procedure for superconducting integrated circuits

    International Nuclear Information System (INIS)

    Saitoh, K.; Soutome, Y.; Tarutani, Y.; Takagi, K.

    1999-01-01

    We have developed and tested a new circuit simulation procedure for superconducting integrated circuits which can be used to optimize circuit parameters. This method reveals a stable operation region in the circuit parameter space in connection with the global bias margin by means of a contour plot of the global bias margin versus the circuit parameters. An optimal set of parameters with margins larger than these of the initial values has been found in the stable region. (author)

  16. Controller tuning with evolutionary multiobjective optimization a holistic multiobjective optimization design procedure

    CERN Document Server

    Reynoso Meza, Gilberto; Sanchis Saez, Javier; Herrero Durá, Juan Manuel

    2017-01-01

    This book is devoted to Multiobjective Optimization Design (MOOD) procedures for controller tuning applications, by means of Evolutionary Multiobjective Optimization (EMO). It presents developments in tools, procedures and guidelines to facilitate this process, covering the three fundamental steps in the procedure: problem definition, optimization and decision-making. The book is divided into four parts. The first part, Fundamentals, focuses on the necessary theoretical background and provides specific tools for practitioners. The second part, Basics, examines a range of basic examples regarding the MOOD procedure for controller tuning, while the third part, Benchmarking, demonstrates how the MOOD procedure can be employed in several control engineering problems. The fourth part, Applications, is dedicated to implementing the MOOD procedure for controller tuning in real processes.

  17. Applied field test procedures on petroleum release sites

    International Nuclear Information System (INIS)

    Gilbert, G.; Nichols, L.

    1995-01-01

    The effective remediation of petroleum contaminated soils and ground water is a significant issue for Williams Pipe Line Co. (Williams): costing $6.8 million in 1994. It is in the best interest, then, for Williams to adopt approaches and apply technologies that will be both cost-effective and comply with regulations. Williams has found the use of soil vapor extraction (SVE) and air sparging (AS) field test procedures at the onset of a petroleum release investigation/remediation accomplish these goals. This paper focuses on the application of AS/SVE as the preferred technology to a specific type of remediation: refined petroleum products. In situ field tests are used prior to designing a full-scale remedial system to first validate or disprove initial assumptions on applicability of the technology. During the field test, remedial system design parameters are also collected to tailor the design and operation of a full-scale system to site specific conditions: minimizing cost and optimizing effectiveness. In situ field tests should be designed and operated to simulate as close as possible the operation of a full-scale remedial system. The procedures of an in situ field test will be presented. The results of numerous field tests and the associated costs will also be evaluated and compared to full-scale remedial systems and total project costs to demonstrate overall effectiveness. There are many advantages of As/SVE technologies over conventional fluid extraction or SVE systems alone. However, the primary advantage is the ability to simultaneously reduce volatile and biodegradable compound concentrations in the phreatic, capillary fringe, and unsaturated zones

  18. Abdominoplasty for Ladd's procedure: optimizing access and esthetics

    African Journals Online (AJOL)

    Abdominoplasty for Ladd's procedure: optimizing access and esthetics. Rachel Aliotta, Neilendu Kundu, Anthony Stallion, Christi Cavaliere. Abstract. Rotational anomalies occur when there is an abnormal arrest of rotation in the embryonic gut during development. The characteristic population affected is considered to be ...

  19. An optimization procedure for borehole emplacement in fractured media

    International Nuclear Information System (INIS)

    Billaux, D.; Guerin, F.

    1998-01-01

    Specifying the position and orientation of the 'next borehole(s)' in a fractured medium, from prior incomplete knowledge of the fracture field and depending on the objectives assigned to this new borehole(s), is a crucial point in the iterative process of site characterization. The work described here explicitly includes site knowledge and specific objectives in a tractable procedure that checks possible borehole characteristics, and rates all trial boreholes according to their compliance with objectives. The procedure is based on the following ideas : Firstly, the optimization problem is strongly constrained, since feasible borehole head locations and borehole dips are generally limited. Secondly, a borehole is an 'access point' to the fracture network. Finally, when performing a flow or tracer test, the information obtained through the monitoring system will be best if this system detects the largest possible share of the flow induced by the test, and if it cuts the most 'interesting' flow paths. The optimization is carried out in four steps. 1) All possible borehole configurations are defined and stored. Typically, several hundred possible boreholes are created. Existing boreholes are also specified. 2) Stochastic fracture networks reproducing known site characteristics are generated. 3) A purely geometrical rating of all boreholes is used to select the 'geometrically best' boreholes or groups of boreholes. 4) Among the boreholes selected by the geometrical rating, the best one(s) is chosen by simulating the experiment for which it will be used and checking flowrates through possible boreholes. This method is applied to study the emplacement of a set of five monitoring boreholes prior to the sinking of a shaft for a planned underground laboratory in a granite massif in France (Vienne site). Twelve geometrical parameters are considered for each possible borehole. A detailed statistical study helps decide on the shape of a minimization function. This is then used

  20. Improving the efficiency of aerodynamic shape optimization procedures

    Science.gov (United States)

    Burgreen, Greg W.; Baysal, Oktay; Eleshaky, Mohamed E.

    1992-01-01

    The computational efficiency of an aerodynamic shape optimization procedure which is based on discrete sensitivity analysis is increased through the implementation of two improvements. The first improvement involves replacing a grid point-based approach for surface representation with a Bezier-Bernstein polynomial parameterization of the surface. Explicit analytical expressions for the grid sensitivity terms are developed for both approaches. The second improvement proposes the use of Newton's method in lieu of an alternating direction implicit (ADI) methodology to calculate the highly converged flow solutions which are required to compute the sensitivity coefficients. The modified design procedure is demonstrated by optimizing the shape of an internal-external nozzle configuration. A substantial factor of 8 decrease in computational time for the optimization process was achieved by implementing both of the design improvements.

  1. Optimization Models for Petroleum Field Exploitation

    Energy Technology Data Exchange (ETDEWEB)

    Jonsbraaten, Tore Wiig

    1998-12-31

    This thesis presents and discusses various models for optimal development of a petroleum field. The objective of these optimization models is to maximize, under many uncertain parameters, the project`s expected net present value. First, an overview of petroleum field optimization is given from the point of view of operations research. Reservoir equations for a simple reservoir system are derived and discretized and included in optimization models. Linear programming models for optimizing production decisions are discussed and extended to mixed integer programming models where decisions concerning platform, wells and production strategy are optimized. Then, optimal development decisions under uncertain oil prices are discussed. The uncertain oil price is estimated by a finite set of price scenarios with associated probabilities. The problem is one of stochastic mixed integer programming, and the solution approach is to use a scenario and policy aggregation technique developed by Rockafellar and Wets although this technique was developed for continuous variables. Stochastic optimization problems with focus on problems with decision dependent information discoveries are also discussed. A class of ``manageable`` problems is identified and an implicit enumeration algorithm for finding optimal decision policy is proposed. Problems involving uncertain reservoir properties but with a known initial probability distribution over possible reservoir realizations are discussed. Finally, a section on Nash-equilibrium and bargaining in an oil reservoir management game discusses the pool problem arising when two lease owners have access to the same underlying oil reservoir. Because the oil tends to migrate, both lease owners have incentive to drain oil from the competitors part of the reservoir. The discussion is based on a numerical example. 107 refs., 31 figs., 14 tabs.

  2. The mean field theory in EM procedures for blind Markov random field image restoration.

    Science.gov (United States)

    Zhang, J

    1993-01-01

    A Markov random field (MRF) model-based EM (expectation-maximization) procedure for simultaneously estimating the degradation model and restoring the image is described. The MRF is a coupled one which provides continuity (inside regions of smooth gray tones) and discontinuity (at region boundaries) constraints for the restoration problem which is, in general, ill posed. The computational difficulty associated with the EM procedure for MRFs is resolved by using the mean field theory from statistical mechanics. An orthonormal blur decomposition is used to reduce the chances of undesirable locally optimal estimates. Experimental results on synthetic and real-world images show that this approach provides good blur estimates and restored images. The restored images are comparable to those obtained by a Wiener filter in mean-square error, but are most visually pleasing.

  3. Optimization of 3D Field Design

    Science.gov (United States)

    Logan, Nikolas; Zhu, Caoxiang

    2017-10-01

    Recent progress in 3D tokamak modeling is now leveraged to create a conceptual design of new external 3D field coils for the DIII-D tokamak. Using the IPEC dominant mode as a target spectrum, the Finding Optimized Coils Using Space-curves (FOCUS) code optimizes the currents and 3D geometry of multiple coils to maximize the total set's resonant coupling. The optimized coils are individually distorted in space, creating toroidal ``arrays'' containing a variety of shapes that often wrap around a significant poloidal extent of the machine. The generalized perturbed equilibrium code (GPEC) is used to determine optimally efficient spectra for driving total, core, and edge neoclassical toroidal viscosity (NTV) torque and these too provide targets for the optimization of 3D coil designs. These conceptual designs represent a fundamentally new approach to 3D coil design for tokamaks targeting desired plasma physics phenomena. Optimized coil sets based on plasma response theory will be relevant to designs for future reactors or on any active machine. External coils, in particular, must be optimized for reliable and efficient fusion reactor designs. Work supported by the US Department of Energy under DE-AC02-09CH11466.

  4. Penumbra modifier for optimal electron field combination

    International Nuclear Information System (INIS)

    El-Sherbini, N.; Hejazy, M.; Khalil, W.

    2008-01-01

    Treatment with megavoltage electron beam is ideal for irradiating shallow seated tumors because of their limited range in tissues. However, the treatment of extended areas with electrons requires the use of two or more adjacent fields. Variations may arise at the junction of the fields. These dose variations come from the presence of large bulges in the low value isodose curves created by electron beam divergence and lateral scattering in tissues. Overlapping of these bulges, creates a high dose region at depths. While constriction of the isodose curves near the surface may produce a Long-term follow-up study critically on the fields separation. To overcome this problem, several authors have proposed techniques for matching electron beam edge in such a way as to make the overlap region as uniform as possible. The simplest approach to the problem is to optimize the skin gap between the two adjacent electron field edges. The increased lateral scatter of low-energy electrons and the machine specific characteristics of an electron beam penumbra make the determination of an optimized skin gap somewhat complicated. Optimization is achieved by a complete set of trial and error measurements. The main limitation to the usefulness of the optimized skin gap technique is the strong sensitivity of the dose distribution in the field junction region to small deviation in field separation or in the angulation of the incident electron beams, making it strongly dependent on positioning. The present study is done at electron beam energies of 6, 8, and 15 MeV. The method depends on the abutment of different field areas using beam edge modifier (Penumbra Generator) made of cerrobend. The objectives of this study are to present a systematic study of the modified electron field for better under standing of the behavior and physical characteristics of the penumbra generator, and to investigate the feasibility of using this technique for large electron fields. Also to obtain a quantitative

  5. Optimization of procedure for calibration with radiometer/photometer

    International Nuclear Information System (INIS)

    Detilly, Isabelle

    2009-01-01

    A test procedure for the radiometer/photometer calibrations mark International Light at the Laboratorio de Fotometria y Tecnologia Laser (LAFTA) de la Escuela de Ingenieria Electrica de la Universidad de Costa Rica is established. Two photometric banks are used as experimental set and two calibrations were performed of the International Light. A basic procedure established in the laboratory, is used for calibration from measurements of illuminance and luminous intensity. Some dependent variations of photometric banks used in the calibration process, the programming of the radiometer/photometer and the applied methodology showed the results. The procedure for calibration with radiometer/photometer can be improved by optimizing the programming process of the measurement instrument and possible errors can be minimized by using the recommended procedure. (author) [es

  6. Optimization by GRASP greedy randomized adaptive search procedures

    CERN Document Server

    Resende, Mauricio G C

    2016-01-01

    This is the first book to cover GRASP (Greedy Randomized Adaptive Search Procedures), a metaheuristic that has enjoyed wide success in practice with a broad range of applications to real-world combinatorial optimization problems. The state-of-the-art coverage and carefully crafted pedagogical style lends this book highly accessible as an introductory text not only to GRASP, but also to combinatorial optimization, greedy algorithms, local search, and path-relinking, as well as to heuristics and metaheuristics, in general. The focus is on algorithmic and computational aspects of applied optimization with GRASP with emphasis given to the end-user, providing sufficient information on the broad spectrum of advances in applied optimization with GRASP. For the more advanced reader, chapters on hybridization with path-relinking and parallel and continuous GRASP present these topics in a clear and concise fashion. Additionally, the book offers a very complete annotated bibliography of GRASP and combinatorial optimizat...

  7. Time Optimal Synchronization Procedure and Associated Feedback Loops

    CERN Document Server

    Angoletta, Maria Elena; CERN. Geneva. ATS Department

    2016-01-01

    A procedure to increase the speed of currently used synchronization loops in a synchrotron by an order of magnitude is presented. Beams dynamics constraint imposes an upper limit on excursions in stable phase angle, and the procedure presented exploits this limit to arrive in the synchronized state from an arbitrary initial state in the fastest possible way. Detailed corrector design for beam phase loop, differential frequency loop and final synchronization loop is also presented. Finally, an overview of the synchronization methods currently deployed in some other CERN’s machines is provided, together with a brief comparison with the newly proposed time-optimal algorithm.

  8. Optimal field splitting for large intensity-modulated fields

    International Nuclear Information System (INIS)

    Kamath, Srijit; Sahni, Sartaj; Ranka, Sanjay; Li, Jonathan; Palta, Jatinder

    2004-01-01

    The multileaf travel range limitations on some linear accelerators require the splitting of a large intensity-modulated field into two or more adjacent abutting intensity-modulated subfields. The abutting subfields are then delivered as separate treatment fields. This workaround not only increases the treatment delivery time but it also increases the total monitor units (MU) delivered to the patient for a given prescribed dose. It is imperative that the cumulative intensity map of the subfields is exactly the same as the intensity map of the large field generated by the dose optimization algorithm, while satisfying hardware constraints of the delivery system. In this work, we describe field splitting algorithms that split a large intensity-modulated field into two or more intensity-modulated subfields with and without feathering, with optimal MU efficiency while satisfying the hardware constraints. Compared to a field splitting technique (without feathering) used in a commercial planning system, our field splitting algorithm (without feathering) shows a decrease in total MU of up to 26% on clinical cases and up to 63% on synthetic cases

  9. Structural analysis and optimization procedure of the TFTR device substructure

    International Nuclear Information System (INIS)

    Driesen, G.

    1975-10-01

    A structural evaluation of the TFTR device substructure is performed in order to verify the feasibility of the proposed design concept as well as to establish a design optimization procedure for minimizing the material and fabrication cost of the substructure members. A preliminary evaluation of the seismic capability is also presented. The design concept on which the analysis is based is consistent with that described in the Conceptual Design Status Briefing report dated June 18, 1975

  10. Image-Optimized Coronal Magnetic Field Models

    Science.gov (United States)

    Jones, Shaela I.; Uritsky, Vadim; Davila, Joseph M.

    2017-01-01

    We have reported previously on a new method we are developing for using image-based information to improve global coronal magnetic field models. In that work we presented early tests of the method which proved its capability to improve global models based on flawed synoptic magnetograms, given excellent constraints on the field in the model volume. In this follow-up paper we present the results of similar tests given field constraints of a nature that could realistically be obtained from quality white-light coronagraph images of the lower corona. We pay particular attention to difficulties associated with the line-of-sight projection of features outside of the assumed coronagraph image plane, and the effect on the outcome of the optimization of errors in localization of constraints. We find that substantial improvement in the model field can be achieved with this type of constraints, even when magnetic features in the images are located outside of the image plane.

  11. Image-optimized Coronal Magnetic Field Models

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Shaela I.; Uritsky, Vadim; Davila, Joseph M., E-mail: shaela.i.jones-mecholsky@nasa.gov, E-mail: shaela.i.jonesmecholsky@nasa.gov [NASA Goddard Space Flight Center, Code 670, Greenbelt, MD 20771 (United States)

    2017-08-01

    We have reported previously on a new method we are developing for using image-based information to improve global coronal magnetic field models. In that work, we presented early tests of the method, which proved its capability to improve global models based on flawed synoptic magnetograms, given excellent constraints on the field in the model volume. In this follow-up paper, we present the results of similar tests given field constraints of a nature that could realistically be obtained from quality white-light coronagraph images of the lower corona. We pay particular attention to difficulties associated with the line-of-sight projection of features outside of the assumed coronagraph image plane and the effect on the outcome of the optimization of errors in the localization of constraints. We find that substantial improvement in the model field can be achieved with these types of constraints, even when magnetic features in the images are located outside of the image plane.

  12. Biaxial testing for fabrics and foils optimizing devices and procedures

    CERN Document Server

    Beccarelli, Paolo

    2015-01-01

    This book offers a well-structured, critical review of current design practice for tensioned membrane structures, including a detailed analysis of the experimental data required and critical issues relating to the lack of a set of design codes and testing procedures. The technical requirements for biaxial testing equipment are analyzed in detail, and aspects that need to be considered when developing biaxial testing procedures are emphasized. The analysis is supported by the results of a round-robin exercise comparing biaxial testing machines that involved four of the main research laboratories in the field. The biaxial testing devices and procedures presently used in Europe are extensively discussed, and information is provided on the design and implementation of a biaxial testing rig for architectural fabrics at Politecnico di Milano, which represents a benchmark in the field. The significance of the most recent developments in biaxial testing is also explored.

  13. Numerical Procedure for Optimizing Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Mihai Razvan Mitroi

    2014-01-01

    Full Text Available We propose a numerical procedure consisting of a simplified physical model and a numerical method with the aim of optimizing the performance parameters of dye-sensitized solar cells (DSSCs. We calculate the real rate of absorbed photons (in the dye spectral range Grealx by introducing a factor β<1 in order to simplify the light absorption and reflection on TCO electrode. We consider the electrical transport to be purely diffusive and the recombination process only to occur between electrons from the TiO2 conduction band and anions from the electrolyte. The used numerical method permits solving the system of differential equations resulting from the physical model. We apply the proposed numerical procedure on a classical DSSC based on Ruthenium dye in order to validate it. For this, we simulate the J-V characteristics and calculate the main parameters: short-circuit current density Jsc, open circuit voltage Voc, fill factor FF, and power conversion efficiency η. We analyze the influence of the nature of semiconductor (TiO2 and dye and also the influence of different technological parameters on the performance parameters of DSSCs. The obtained results show that the proposed numerical procedure is suitable for developing a numerical simulation platform for improving the DSSCs performance by choosing the optimal parameters.

  14. Topology Optimized Nanostrips for Electric Field Enhancements

    DEFF Research Database (Denmark)

    Vester-Petersen, Joakim; Christiansen, Rasmus E.; Julsgaard, Brian

    This work addresses efficiency improvements of solar cells by manipulating the spectrum of sunlight to bettermatch the range of efficient current generation. The intrinsic transmission losses in crystalline silicon can effectivelybe reduced using photon upconversion in erbium ions in which low...... energy photons are converted to higher energy photons able to bridge the band gap energy and contribute the energy generation. The upconversion process in erbium is inefficient under the natural solar irradiation, and without any electric field enhancements of the incident light, the process...... is negligible for photo-voltaic applications. However, the probability for upconversion can be increased by focusing the incident light onto the erbium ions using optimized metal nanostructures[1, 2, 3]. The aim of this work is to increase the photon upconversion yield by optimizing the design of metalic...

  15. Estimating cellular parameters through optimization procedures: elementary principles and applications

    Directory of Open Access Journals (Sweden)

    Akatsuki eKimura

    2015-03-01

    Full Text Available Construction of quantitative models is a primary goal of quantitative biology, which aims to understand cellular and organismal phenomena in a quantitative manner. In this article, we introduce optimization procedures to search for parameters in a quantitative model that can reproduce experimental data. The aim of optimization is to minimize the sum of squared errors (SSE in a prediction or to maximize likelihood. A (local maximum of likelihood or (local minimum of the SSE can efficiently be identified using gradient approaches. Addition of a stochastic process enables us to identify the global maximum/minimum without becoming trapped in local maxima/minima. Sampling approaches take advantage of increasing computational power to test numerous sets of parameters in order to determine the optimum set. By combining Bayesian inference with gradient or sampling approaches, we can estimate both the optimum parameters and the form of the likelihood function related to the parameters. Finally, we introduce four examples of research that utilize parameter optimization to obtain biological insights from quantified data: transcriptional regulation, bacterial chemotaxis, morphogenesis, and cell cycle regulation. With practical knowledge of parameter optimization, cell and developmental biologists can develop realistic models that reproduce their observations and thus, obtain mechanistic insights into phenomena of interest.

  16. Penumbra modifier for optimal electron fields combination

    International Nuclear Information System (INIS)

    ElSherbini, N.; Hejazy, M.A.; Khalil, W.

    2003-01-01

    Abutment of two or more electron fields to irradiate extended areas may lead to significant dose inhomogeneities in the junction region. This study describes the geometric and dosimetric characteristics of a device developed to modify the penumbra of an electron beam and therapy improve of dose uniformity in the over lap region when fields are abutted. The device is lipowitz metal block placed on top of the insertion plate of the electron applicator and positioned to stop part of he electron beam on side of field abutment. The air-scattered electrons beyond the block increase the penumbra width from about 1,4 to 2-7-43.4 cm at SSD 100 cm, the modified penumbra is broad and almost linear at all depths for the 6.8, and 15 MeV electron beams used. Film dosimetry was used to obtain profiles, iso-dose distributions, single modified beams and matched fields of 6, 10, and 15 MeV. Wellhofer dosimetry system was used to obtain beam profiles and iso-dose distributions of single modified beams needed for CADPLAN treatment planning system, which used to optimize and compare the skin gap to be used and to quantify the dose uniformity in a junction of the field separation for both modified and non-modified beams. Results are presented for various field configurations without the penumbra modifier; lateral setup error of 2-3 mm may introduce dose variations of 20% or more in the junction region. Similar setup error cause less than 5% dose variations when the penumbra modifier is used to match the field

  17. Optimal Procedure for siting of Nuclear Power Plant

    International Nuclear Information System (INIS)

    Aziuddin, Khairiah Binti; Park, Seo Yeon; Roh, Myung Sub

    2013-01-01

    This study discusses on a simulation approach for sensitivity analysis of the weights of multi-criteria decision models. The simulation procedures can also be used to aid the actual decision process, particularly when the task is to select a subset of superior alternatives. This study is to identify the criteria or parameters which are sensitive to the weighting factor that can affect the results in the decision making process to determine the optimal site for nuclear power plant (NPP) site. To perform this study, we adhere to IAEA NS-R-3 and DS 433. The siting process for nuclear installation consists of site survey and site selection stages. The siting process generally consists of an investigation of a large region to select one or more candidate sites by surveying the sites. After comparing the ROI, two candidate sites are compared for final determination, which are Wolsong and Kori site. Some assumptions are taken into consideration due to limitations and constraints throughout performing this study. Sensitivity analysis of multi criteria decision models is performed in this study to determine the optimal site in the site selection stage. Logical Decisions software will be employed as a tool to perform this analysis. Logical Decisions software helps to formulate the preferences and then rank the alternatives. It provides clarification of the rankings and hence aids the decision makers on evaluating the alternatives, and finally draw a conclusion on the selection of the optimal site

  18. Optimal Procedure for siting of Nuclear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Aziuddin, Khairiah Binti; Park, Seo Yeon; Roh, Myung Sub [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2013-10-15

    This study discusses on a simulation approach for sensitivity analysis of the weights of multi-criteria decision models. The simulation procedures can also be used to aid the actual decision process, particularly when the task is to select a subset of superior alternatives. This study is to identify the criteria or parameters which are sensitive to the weighting factor that can affect the results in the decision making process to determine the optimal site for nuclear power plant (NPP) site. To perform this study, we adhere to IAEA NS-R-3 and DS 433. The siting process for nuclear installation consists of site survey and site selection stages. The siting process generally consists of an investigation of a large region to select one or more candidate sites by surveying the sites. After comparing the ROI, two candidate sites are compared for final determination, which are Wolsong and Kori site. Some assumptions are taken into consideration due to limitations and constraints throughout performing this study. Sensitivity analysis of multi criteria decision models is performed in this study to determine the optimal site in the site selection stage. Logical Decisions software will be employed as a tool to perform this analysis. Logical Decisions software helps to formulate the preferences and then rank the alternatives. It provides clarification of the rankings and hence aids the decision makers on evaluating the alternatives, and finally draw a conclusion on the selection of the optimal site.

  19. Optimization of the semiautomated Macdonald and Savage procedure

    International Nuclear Information System (INIS)

    Kuvik, V.; Vrbova, L.

    1990-06-01

    Several topics concerning the Macdonald and Savage (MD/S) procedure used for the potentiometric determination of plutonium were included in the programme of Analytical Services requested form CCL Rez. One part of the work was focussed on eliminating the variations of the Pu results and titems. The sulfuric reagent should be aged at least for one week. The optimal composition of the sulfuric reagent is 2M sulfuric acid + 0.2M sulfuric acid + 0.25 cerous nitrate. The excess of 0.002 N permanganate may vary between 0.016 and 0.1 ml. A variation of 0.02M oxalic acid between 0.08 and 0.14 ml is acceptable. The presence of Ga results in a slight positive bias of the Pu determination at ratio. Ga/Pu = 0.25. 3 refs, 18 tabs

  20. Procedures for field measurements in the case of nuclear accident

    International Nuclear Information System (INIS)

    Barisic, D.; Lulic, S.

    2000-01-01

    Very simplified, reduced and shorted procedures for main objectives of emergency field monitoring in case of nuclear accident are given only. They could be implemented in Croatia using resources nowadays available. Procedures for gamma/beta dose rates in plume and ground deposition survey and unknown situation evaluation, procedures for alpha and gamma/beta surface contamination measurement, field personnel/equipment contamination and decontamination measurement as well as for in-situ gamma spectrometry measurements are presented. Purpose, short discussion, general precautions and limitations as well as basic equipment and supplies needed are given for all of procedures discussed also. Only measuring steps are given with more details in form of short and clear instructions. (author)

  1. Optimization of digitization procedures in cultural heritage preservation

    Science.gov (United States)

    Martínez, Bea; Mitjà, Carles; Escofet, Jaume

    2013-11-01

    The digitization of both volumetric and flat objects is the nowadays-preferred method in order to preserve cultural heritage items. High quality digital files obtained from photographic plates, films and prints, paintings, drawings, gravures, fabrics and sculptures, allows not only for a wider diffusion and on line transmission, but also for the preservation of the original items from future handling. Early digitization procedures used scanners for flat opaque or translucent objects and camera only for volumetric or flat highly texturized materials. The technical obsolescence of the high-end scanners and the improvement achieved by professional cameras has result in a wide use of cameras with digital back to digitize any kind of cultural heritage item. Since the lens, the digital back, the software controlling the camera and the digital image processing provide a wide range of possibilities, there is necessary to standardize the methods used in the reproduction work leading to preserve as high as possible the original item properties. This work presents an overview about methods used for camera system characterization, as well as the best procedures in order to identify and counteract the effect of the lens residual aberrations, sensor aliasing, image illumination, color management and image optimization by means of parametric image processing. As a corollary, the work shows some examples of reproduction workflow applied to the digitization of valuable art pieces and glass plate photographic black and white negatives.

  2. Procedures for field chemical analyses of water samples

    International Nuclear Information System (INIS)

    Korte, N.; Ealey, D.

    1983-12-01

    A successful water-quality monitoring program requires a clear understanding of appropriate measurement procedures in order to obtain reliable field data. It is imperative that the responsible personnel have a thorough knowledge of the limitations of the techniques being used. Unfortunately, there is a belief that field analyses are simple and straightforward. Yet, significant controversy as well as misuse of common measurement techniques abounds. This document describes procedures for field measurements of pH, carbonate and bicarbonate, specific conductance, dissolved oxygen, nitrate, Eh, and uranium. Each procedure section includes an extensive discussion regarding the limitations of the method as well as brief discussions of calibration procedures and available equipment. A key feature of these procedures is the consideration given to the ultimate use of the data. For example, if the data are to be used for geochemical modeling, more precautions are needed. In contrast, routine monitoring conducted merely to recognize gross changes can be accomplished with less effort. Finally, quality assurance documentation for each measurement is addressed in detail. Particular attention is given to recording sufficient information such that decisions concerning the quality of the data can be easily made. Application of the procedures and recommendations presented in this document should result in a uniform and credible water-quality monitoring program. 22 references, 4 figures, 3 tables

  3. A PROCEDURE FOR DETERMINING OPTIMAL FACILITY LOCATION AND SUB-OPTIMAL POSITIONS

    Directory of Open Access Journals (Sweden)

    P.K. Dan

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: This research presents a methodology for determining the optimal location of a new facility, having physical flow interaction of various degrees with other existing facilities in the presence of barriers impeding the shortest flow-path as well as the sub-optimal iso-cost positions. It also determines sub-optimal iso-cost positions with additional cost or penalty for not being able to site it at the computed optimal point. The proposed methodology considers all types of quadrilateral barrier or forbidden region configurations to generalize and by-pass such impenetrable obstacles, and adopts a scheme of searching through the vertices of the quadrilaterals to determine the alternative shortest flow-path. This procedure of obstacle avoidance is novel. Software has been developed to facilitate computations for the search algorithm to determine the optimal and iso-cost co-ordinates. The test results are presented.

    AFRIKAANSE OPSOMMING: Die navorsing behandel ‘n procedure vir die bepaling van optimum stigtingsposisie vir ‘n onderneming met vloei vanaf ander bestaande fasiliteite in die teenwoordigheid van ‘n verskeidenheid van randvoorwaardes. Die prodedure lewer as resultaat suboptimale isokoste-stigtingsplekke met bekendmaking van die koste wat onstaan a.g.v. afwyking van die randvoorwaardlose optimum oplossingskoste, die prosedure maak gebruik van ‘n vindingryke soekmetode wat toegepas word op niersydige meerkundige voorstellings vir die bepaling van korste roetes wat versperring omseil. Die prosedure word onderskei deur programmatuur. Toetsresultate word voorgehou.

  4. The development of simple field based procedures for extraction of ...

    African Journals Online (AJOL)

    Field and laboratory experiments were conducted to develop procedures for extracting volatiles from the vine of Adenia cissampeloides which could effect the highest yield at the lowest extraction costs and also could be produced at the cottage industry level. The participatory rural appraisal technique was used to ensure ...

  5. Optimization of exposure procedures for sub-quarter-micron CMOS applications

    Science.gov (United States)

    Hotta, Shoji; Onozuka, Toshihiko; Fukumoto, Keiko; Shirai, Seiichiro; Okazaki, Shinji

    1998-06-01

    We investigated various exposure procedures to minimize the Critical Dimension (CD) variation for the patterning of sub- quarter micron gates. To examine dependence of the CD variation on the pattern pitch and defocus conditions, the light intensity profiles of four different mask structures: (1) a binary mask with clear field, (2) a binary mask with dark field, (3) a phase-edge type phase-shifting mask (a phase-edge PSM) with clear field, and (4) a halftone phase- shifting mask (a halftone PSM) were compared, where exposure wavelength was 248 nm and numerical aperture (NA) of KrF stepper was 0.55. For 200-nm gate patterns, dependence of the CD variation on the pattern pitch and defocus conditions was minimized by a phase-edge PSM with clear field. By optimizing the illumination condition for a phase-edge PSM exposure, we obtained the CD variation of 10 nm at the minimum gate pitch of 0.8 micrometer and the defocus condition of plus or minus 0.4 micrometer. Applying the optimized exposure procedure to the device fabrication process, we obtained the total CD variation of plus or minus 27 nm.

  6. Development of multidisciplinary design optimization procedures for smart composite wings and turbomachinery blades

    Science.gov (United States)

    Jha, Ratneshwar

    Multidisciplinary design optimization (MDO) procedures have been developed for smart composite wings and turbomachinery blades. The analysis and optimization methods used are computationally efficient and sufficiently rigorous. Therefore, the developed MDO procedures are well suited for actual design applications. The optimization procedure for the conceptual design of composite aircraft wings with surface bonded piezoelectric actuators involves the coupling of structural mechanics, aeroelasticity, aerodynamics and controls. The load carrying member of the wing is represented as a single-celled composite box beam. Each wall of the box beam is analyzed as a composite laminate using a refined higher-order displacement field to account for the variations in transverse shear stresses through the thickness. Therefore, the model is applicable for the analysis of composite wings of arbitrary thickness. Detailed structural modeling issues associated with piezoelectric actuation of composite structures are considered. The governing equations of motion are solved using the finite element method to analyze practical wing geometries. Three-dimensional aerodynamic computations are performed using a panel code based on the constant-pressure lifting surface method to obtain steady and unsteady forces. The Laplace domain method of aeroelastic analysis produces root-loci of the system which gives an insight into the physical phenomena leading to flutter/divergence and can be efficiently integrated within an optimization procedure. The significance of the refined higher-order displacement field on the aeroelastic stability of composite wings has been established. The effect of composite ply orientations on flutter and divergence speeds has been studied. The Kreisselmeier-Steinhauser (K-S) function approach is used to efficiently integrate the objective functions and constraints into a single envelope function. The resulting unconstrained optimization problem is solved using the

  7. Soft Tissue Surgical Procedures for Optimizing Anterior Implant Esthetics

    Science.gov (United States)

    Ioannou, Andreas L.; Kotsakis, Georgios A.; McHale, Michelle G.; Lareau, Donald E.; Hinrichs, James E.; Romanos, Georgios E.

    2015-01-01

    Implant dentistry has been established as a predictable treatment with excellent clinical success to replace missing or nonrestorable teeth. A successful esthetic implant reconstruction is predicated on two fundamental components: the reproduction of the natural tooth characteristics on the implant crown and the establishment of soft tissue housing that will simulate a healthy periodontium. In order for an implant to optimally rehabilitate esthetics, the peri-implant soft tissues must be preserved and/or augmented by means of periodontal surgical procedures. Clinicians who practice implant dentistry should strive to achieve an esthetically successful outcome beyond just osseointegration. Knowledge of a variety of available techniques and proper treatment planning enables the clinician to meet the ever-increasing esthetic demands as requested by patients. The purpose of this paper is to enhance the implant surgeon's rationale and techniques beyond that of simply placing a functional restoration in an edentulous site to a level whereby an implant-supported restoration is placed in reconstructed soft tissue, so the site is indiscernible from a natural tooth. PMID:26124837

  8. Topology optimization of nanoparticles for localized electromagnetic field enhancement

    DEFF Research Database (Denmark)

    Christiansen, Rasmus Ellebæk; Vester-Petersen, Joakim; Madsen, Søren Peder

    2017-01-01

    We consider the design of individual and periodic arrangements of metal or semiconductor nanoparticles for localized electromagnetic field enhancement utilizing a topology optimization based numerical framework as the design tool. We aim at maximizing a function of the electromagnetic field...

  9. Optimal sampling schemes for vegetation and geological field visits

    CSIR Research Space (South Africa)

    Debba, Pravesh

    2012-07-01

    Full Text Available The presentation made to Wits Statistics Department was on common classification methods used in the field of remote sensing, and the use of remote sensing to design optimal sampling schemes for field visits with applications in vegetation...

  10. Computer Based Procedures for Field Workers - FY16 Research Activities

    International Nuclear Information System (INIS)

    Oxstrand, Johanna; Bly, Aaron

    2016-01-01

    The Computer-Based Procedure (CBP) research effort is a part of the Light-Water Reactor Sustainability (LWRS) Program, which provides the technical foundations for licensing and managing the long-term, safe, and economical operation of current nuclear power plants. One of the primary missions of the LWRS program is to help the U.S. nuclear industry adopt new technologies and engineering solutions that facilitate the continued safe operation of the plants and extension of the current operating licenses. One area that could yield tremendous savings in increased efficiency and safety is in improving procedure use. A CBP provides the opportunity to incorporate context-driven job aids, such as drawings, photos, and just-in-time training. The presentation of information in CBPs can be much more flexible and tailored to the task, actual plant condition, and operation mode. The dynamic presentation of the procedure will guide the user down the path of relevant steps, thus minimizing time spent by the field worker to evaluate plant conditions and decisions related to the applicability of each step. This dynamic presentation of the procedure also minimizes the risk of conducting steps out of order and/or incorrectly assessed applicability of steps. This report provides a summary of the main research activities conducted in the Computer-Based Procedures for Field Workers effort since 2012. The main focus of the report is on the research activities conducted in fiscal year 2016. The activities discussed are the Nuclear Electronic Work Packages - Enterprise Requirements initiative, the development of a design guidance for CBPs (which compiles all insights gained through the years of CBP research), the facilitation of vendor studies at the Idaho National Laboratory (INL) Advanced Test Reactor (ATR), a pilot study for how to enhance the plant design modification work process, the collection of feedback from a field evaluation study at Plant Vogtle, and path forward to

  11. Computer Based Procedures for Field Workers - FY16 Research Activities

    Energy Technology Data Exchange (ETDEWEB)

    Oxstrand, Johanna [Idaho National Lab. (INL), Idaho Falls, ID (United States); Bly, Aaron [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-09-01

    The Computer-Based Procedure (CBP) research effort is a part of the Light-Water Reactor Sustainability (LWRS) Program, which provides the technical foundations for licensing and managing the long-term, safe, and economical operation of current nuclear power plants. One of the primary missions of the LWRS program is to help the U.S. nuclear industry adopt new technologies and engineering solutions that facilitate the continued safe operation of the plants and extension of the current operating licenses. One area that could yield tremendous savings in increased efficiency and safety is in improving procedure use. A CBP provides the opportunity to incorporate context-driven job aids, such as drawings, photos, and just-in-time training. The presentation of information in CBPs can be much more flexible and tailored to the task, actual plant condition, and operation mode. The dynamic presentation of the procedure will guide the user down the path of relevant steps, thus minimizing time spent by the field worker to evaluate plant conditions and decisions related to the applicability of each step. This dynamic presentation of the procedure also minimizes the risk of conducting steps out of order and/or incorrectly assessed applicability of steps. This report provides a summary of the main research activities conducted in the Computer-Based Procedures for Field Workers effort since 2012. The main focus of the report is on the research activities conducted in fiscal year 2016. The activities discussed are the Nuclear Electronic Work Packages – Enterprise Requirements initiative, the development of a design guidance for CBPs (which compiles all insights gained through the years of CBP research), the facilitation of vendor studies at the Idaho National Laboratory (INL) Advanced Test Reactor (ATR), a pilot study for how to enhance the plant design modification work process, the collection of feedback from a field evaluation study at Plant Vogtle, and path forward to

  12. Design Guidance for Computer-Based Procedures for Field Workers

    Energy Technology Data Exchange (ETDEWEB)

    Oxstrand, Johanna [Idaho National Lab. (INL), Idaho Falls, ID (United States); Le Blanc, Katya [Idaho National Lab. (INL), Idaho Falls, ID (United States); Bly, Aaron [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-09-01

    Nearly all activities that involve human interaction with nuclear power plant systems are guided by procedures, instructions, or checklists. Paper-based procedures (PBPs) currently used by most utilities have a demonstrated history of ensuring safety; however, improving procedure use could yield significant savings in increased efficiency, as well as improved safety through human performance gains. The nuclear industry is constantly trying to find ways to decrease human error rates, especially human error rates associated with procedure use. As a step toward the goal of improving field workers’ procedure use and adherence and hence improve human performance and overall system reliability, the U.S. Department of Energy Light Water Reactor Sustainability (LWRS) Program researchers, together with the nuclear industry, have been investigating the possibility and feasibility of replacing current paper-based procedures with computer-based procedures (CBPs). PBPs have ensured safe operation of plants for decades, but limitations in paper-based systems do not allow them to reach the full potential for procedures to prevent human errors. The environment in a nuclear power plant is constantly changing, depending on current plant status and operating mode. PBPs, which are static by nature, are being applied to a constantly changing context. This constraint often results in PBPs that are written in a manner that is intended to cover many potential operating scenarios. Hence, the procedure layout forces the operator to search through a large amount of irrelevant information to locate the pieces of information relevant for the task and situation at hand, which has potential consequences of taking up valuable time when operators must be responding to the situation, and potentially leading operators down an incorrect response path. Other challenges related to use of PBPs are management of multiple procedures, place-keeping, finding the correct procedure for a task, and relying

  13. Designing optimal sampling schemes for field visits

    CSIR Research Space (South Africa)

    Debba, Pravesh

    2008-10-01

    Full Text Available This is a presentation of a statistical method for deriving optimal spatial sampling schemes. The research focuses on ground verification of minerals derived from hyperspectral data. Spectral angle mapper (SAM) and spectral feature fitting (SFF...

  14. Design of an X-band accelerating structure using a newly developed structural optimization procedure

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Xiaoxia [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Fang, Wencheng; Gu, Qiang [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Zhao, Zhentang, E-mail: zhaozhentang@sinap.ac.cn [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); University of Chinese Academy of Sciences, Beijing 100049 (China)

    2017-05-11

    An X-band high gradient accelerating structure is a challenging technology for implementation in advanced electron linear accelerator facilities. The present work discusses the design of an X-band accelerating structure for dedicated application to a compact hard X-ray free electron laser facility at the Shanghai Institute of Applied Physics, and numerous design optimizations are conducted with consideration for radio frequency (RF) breakdown, RF efficiency, short-range wakefields, and dipole/quadrupole field modes, to ensure good beam quality and a high accelerating gradient. The designed X-band accelerating structure is a constant gradient structure with a 4π/5 operating mode and input and output dual-feed couplers in a racetrack shape. The design process employs a newly developed effective optimization procedure for optimization of the X-band accelerating structure. In addition, the specific design of couplers providing high beam quality by eliminating dipole field components and reducing quadrupole field components is discussed in detail.

  15. Procedures for Dealing with Optimism Bias in Transport Planning

    DEFF Research Database (Denmark)

    Flyvbjerg, Bent; Glenting, Carsten; Rønnest, Arne Kvist

    of the document are to provide empirically based optimism bias up-lifts for selected reference classes of transport infrastructure projects and provide guidance on using the established uplifts to produce more realistic forecasts for the individual project's capital expenditures. Furthermore, the underlying...... causes and institutional context for optimism bias in British transport projects are discussed and some possibilities for reducing optimism bias in project preparation and decision-making are identified....

  16. A new mixed self-consistent field procedure

    Science.gov (United States)

    Alvarez-Ibarra, A.; Köster, A. M.

    2015-10-01

    A new approach for the calculation of three-centre electronic repulsion integrals (ERIs) is developed, implemented and benchmarked in the framework of auxiliary density functional theory (ADFT). The so-called mixed self-consistent field (mixed SCF) divides the computationally costly ERIs in two sets: far-field and near-field. Far-field ERIs are calculated using the newly developed double asymptotic expansion as in the direct SCF scheme. Near-field ERIs are calculated only once prior to the SCF procedure and stored in memory, as in the conventional SCF scheme. Hence the name, mixed SCF. The implementation is particularly powerful when used in parallel architectures, since all RAM available are used for near-field ERI storage. In addition, the efficient distribution algorithm performs minimal intercommunication operations between processors, avoiding a potential bottleneck. One-, two- and three-dimensional systems are used for benchmarking, showing substantial time reduction in the ERI calculation for all of them. A Born-Oppenheimer molecular dynamics calculation for the Na+55 cluster is also shown in order to demonstrate the speed-up for small systems achievable with the mixed SCF. Dedicated to Sourav Pal on the occasion of his 60th birthday.

  17. Bifurcations of optimal vector fields: an overview

    NARCIS (Netherlands)

    Kiseleva, T.; Wagener, F.; Rodellar, J.; Reithmeier, E.

    2009-01-01

    We develop a bifurcation theory for the solution structure of infinite horizon optimal control problems with one state variable. It turns out that qualitative changes of this structure are connected to local and global bifurcations in the state-costate system. We apply the theory to investigate an

  18. Poloidal field leakage optimization in ETE

    Energy Technology Data Exchange (ETDEWEB)

    Shibata, Carlos Shinya; Montes, Antonio

    1996-12-01

    A very simple but efficient numerical algorithm is used to minimize the Ohmic coil field leakage into the plasma region of the tokamak ETE. After few interactions the code provides the positions and the current required for two pairs of compensation coils. Resulting optimum field intensity distribution is presented and commented. (author). 5 refs., 4 figs., 2 tabs.

  19. Poloidal field leakage optimization in ETE

    International Nuclear Information System (INIS)

    Shibata, Carlos Shinya; Montes, Antonio.

    1996-01-01

    A very simple but efficient numerical algorithm is used to minimize the Ohmic coil field leakage into the plasma region of the tokamak ETE. After few interactions the code provides the positions and the current required for two pairs of compensation coils. Resulting optimum field intensity distribution is presented and commented. (author). 5 refs., 4 figs., 2 tabs

  20. Field Optimization for short Period Undulators

    CERN Document Server

    Peiffer, P; Rossmanith, R; Schoerling, D

    2011-01-01

    Undulators dedicated to low energy electron beams, like Laser Wakefield Accelerators, require very short period lengths to achieve X-ray emission. However, at these short period length (LambdaU ~ 5 mm) it becomes difficult to reach magnetic field amplitudes that lead to a K parameter of >1, which is generally desired. Room temperature permanent magnets and even superconductive undulators using Nb-Ti as conductor material have proven insufficient to achieve the desired field amplitudes. The superconductor Nb$_{3}$Sn has the theoretical potential to achieve the desired fields. However, up to now it is limited by several technological challenges to much lower field values than theoretically predicted. An alternative idea for higher fields is to manufacture the poles of the undulator body from Holmium instead of iron or to use Nb-Ti wires with a higher superconductor/copper ratio. The advantages and challenges of the different options are compared in this contribution.

  1. Optimal design of an automotive magnetorheological brake considering geometric dimensions and zero-field friction heat

    International Nuclear Information System (INIS)

    Nguyen, Q H; Choi, S B

    2010-01-01

    This paper presents an optimal design of a magnetorheological (MR) brake for a middle-sized passenger car which can replace a conventional hydraulic disc-type brake. In the optimization, the required braking torque, the temperature due to zero-field friction of MR fluid, the mass of the brake system and all significant geometric dimensions are considered. After describing the configuration, the braking torque of the proposed MR brake is derived on the basis of the field-dependent Bingham and Herschel–Bulkley rheological model of the MR fluid. The optimal design of the MR brake is then analyzed taking into account available space, mass, braking torque and steady heat generated by zero-field friction torque of the MR brake. The optimization procedure based on the finite element analysis integrated with an optimization tool is proposed to obtain optimal geometric dimensions of the MR brake. Based on the proposed procedure, optimal solutions of single and multiple disc-type MR brakes featuring different types of MR fluid are achieved. From the results, the most effective MR brake for the middle-sized passenger car is identified and some discussions on the performance improvement of the optimized MR brake are described

  2. Dispersant field testing : a review of procedures and considerations

    International Nuclear Information System (INIS)

    Fingas, M.F.

    2004-01-01

    The effectiveness of a dispersant is defined by the amount of oil that the dispersant puts into the water column compared to the amount of oil that was initially spilled. Effectiveness is generally determined visually in plumes of dispersed oil that are visible from ships and aircraft. This paper describes 25 specific issues and technical concerns regarding field testing of dispersant effectiveness. Recent field tests were reviewed and literature that relates to testing procedures was sited. The 25 factors that are important for the appropriate outcome of dispersant field experiments include: mass balance; proper controls; analytical method; differential plume movement; time lag and length of time followed; mathematics of calculation and integration; lower and upper limits of analytical methods; use of remote sensing; thickness measurement; behaviour of oil with surfactant content; surfactant stripping; tracking surface oil and dispersed oil; recovering surface oil; visibility of oil from the surface; background levels of hydrocarbons; fluorescence of dispersant; herding; emulsion breaking; application success; heterogeneity of slick and plume; deposition measurements; true analytical standards; effect of wind on dispersant and slick; dispersant run-off; and weathering of the oil. It was concluded that the most important factors are the ability to determine mass balance, use proper controls, analytical methods and to avoid procedures that give incorrect results. 34 refs., 4 tabs., 1 fig

  3. Analytic Optimization of Near-Field Optical Chirality Enhancement

    Science.gov (United States)

    2017-01-01

    We present an analytic derivation for the enhancement of local optical chirality in the near field of plasmonic nanostructures by tuning the far-field polarization of external light. We illustrate the results by means of simulations with an achiral and a chiral nanostructure assembly and demonstrate that local optical chirality is significantly enhanced with respect to circular polarization in free space. The optimal external far-field polarizations are different from both circular and linear. Symmetry properties of the nanostructure can be exploited to determine whether the optimal far-field polarization is circular. Furthermore, the optimal far-field polarization depends on the frequency, which results in complex-shaped laser pulses for broadband optimization. PMID:28239617

  4. The optimization of the electrostatic field inside the ZEUS forward drift chambers: Calculations and measurements

    International Nuclear Information System (INIS)

    Dobberstein, M.P.; Krawczyk, F.; Schaefer-Jotter, M.

    1990-11-01

    The electrostatic field inside small drift cells shows in general edge effects which are not negligible. These are usually corrected by field shaping wires or strips. The operating voltages of the field shaping electrodes have to be adjusted to maximize the field homogeneity. We present the underlying ideas of such an optimization procedure for the cells of the ZEUS forward drift chambers. Using the finite difference code PROFI, the optimization can be performed automatically by a multiple solution of the Poisson equation. An experimental verification of the optimal voltages was carried out measuring the gas amplifications at the six sense wires. Modifications of the drift cell geometry were necessary for calibration measurements with a laser beam. This caused additional distortions of the electrostatic field. Their influence was calculated using the MAFIA code, which allows to include open boundary conditions. (orig.)

  5. Abdominoplasty for Ladd's procedure: optimizing access and esthetics

    African Journals Online (AJOL)

    often-displeasing incision and visible scar. ... inception and is traditionally performed by making a ... procedure, these highly visible surgical approaches can .... reportedthat she remained symptom free and was pleased with her nearly invisible.

  6. Extragalactic Fields Optimized for Adaptive Optics

    Science.gov (United States)

    2011-03-01

    4Gemini Observatory, Southern Operations Center, c/o AURA, Casilla 603,La Serena, Chile . sObservatories of the Carnegie Institution of Washington...unsuitable anyway. Any such fields would be inaccessible from Chile and be at quite high air mass most of the time for major northem hemisphere...drawback of such a star is not the vertical blooming , which affects a small fraction of the imaging area, but the halos due to internal reflections

  7. A procedure for multi-objective optimization of tire design parameters

    OpenAIRE

    Nikola Korunović; Miloš Madić; Miroslav Trajanović; Miroslav Radovanović

    2015-01-01

    The identification of optimal tire design parameters for satisfying different requirements, i.e. tire performance characteristics, plays an essential role in tire design. In order to improve tire performance characteristics, formulation and solving of multi-objective optimization problem must be performed. This paper presents a multi-objective optimization procedure for determination of optimal tire design parameters for simultaneous minimization of strain energy density at two distinctive zo...

  8. Optimal estimations of random fields using kriging

    International Nuclear Information System (INIS)

    Barua, G.

    2004-01-01

    Kriging is a statistical procedure of estimating the best weights of a linear estimator. Suppose there is a point or an area or a volume of ground over which we do not know a hydrological variable and wish to estimate it. In order to produce an estimator, we need some information to work on, usually available in the form of samples. There can, be an infinite number of linear unbiased estimators for which the weights sum up to one. The problem is how to determine the best weights for which the estimation variance is the least. The system of equations as shown above is generally known as the kriging system and the estimator produced is the kriging estimator. The variance of the kriging estimator can be found by substitution of the weights in the general estimation variance equation. We assume here a linear model for the semi-variogram. Applying the model to the equation, we obtain a set of kriging equations. By solving these equations, we obtain the kriging variance. Thus, for the one-dimensional problem considered, kriging definitely gives a better estimation variance than the extension variance

  9. Development of Optimization Procedure for Design of Package Cushioning

    Science.gov (United States)

    1975-01-01

    that we seek. Vibration Optimization from Random Excitation Excitation power spect : cl density S(U)j) must be specified in 1-octave frequency...CUO INCHES 3.010 INCHES t.11* INCHES •i»i. C ’Sl/llfs Bl.’Ji •COS-Is-jT •" ~» TBI «."»tf<I»l. vf»TIC»L,*xIS MGHIZONT»L J.’" l

  10. Analytical Tools to Improve Optimization Procedures for Lateral Flow Assays

    Directory of Open Access Journals (Sweden)

    Helen V. Hsieh

    2017-05-01

    Full Text Available Immunochromatographic or lateral flow assays (LFAs are inexpensive, easy to use, point-of-care medical diagnostic tests that are found in arenas ranging from a doctor’s office in Manhattan to a rural medical clinic in low resource settings. The simplicity in the LFA itself belies the complex task of optimization required to make the test sensitive, rapid and easy to use. Currently, the manufacturers develop LFAs by empirical optimization of material components (e.g., analytical membranes, conjugate pads and sample pads, biological reagents (e.g., antibodies, blocking reagents and buffers and the design of delivery geometry. In this paper, we will review conventional optimization and then focus on the latter and outline analytical tools, such as dynamic light scattering and optical biosensors, as well as methods, such as microfluidic flow design and mechanistic models. We are applying these tools to find non-obvious optima of lateral flow assays for improved sensitivity, specificity and manufacturing robustness.

  11. A demonstration of magnetic field optimization in LHD

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, S.; Yamada, H. [National Inst. for Fusion Science, Toki, Gifu (Japan); Wakasa, A. [Hokkaido Univ., Graduate School of Engineering, Sapporo, Hokkaido (JP)] [and others

    2002-11-01

    An optimized configuration of the neoclassical transport and the energetic particle confinement to a level typical of so-called 'advanced stellarators' is found by shifting the magnetic axis position in LHD. Electron heat transport and NBI beam ion distribution are investigated in low-collisionality LHD plasma in order to study the magnetic field optimization effect on the thermal plasma transport and the energetic particle confinement. A higher electron temperature is obtained in the optimized configuration, and the transport analysis suggests a considerable effect of neoclassical transport on the electron heat transport assuming the ion-root level of radial electric field. Also a higher energetic ion distribution of NBI beam ions is observed showing the improvement of the energetic particle confinement. These obtained results support a future reactor design by magnetic field optimization in a non-axisymmetric configuration. (author)

  12. A demonstration of magnetic field optimization in LHD

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, S.; Yamada, H. [National Inst. for Fusion Science, Toki, Gifu (Japan); Wakasa, A. [Hokkaido Univ., Graduate School of Engineering, Sapporo, Hokkaido (JP)] [and others

    2002-10-01

    An optimized configuration of the neoclassical transport and the energetic particle confinement to a level typical of so-called 'advanced stellarators' is found by shifting the magnetic axis position in LHD. Electron heat transport and NBI beam ion distribution are investigated in low-collisionality LHD plasma in order to study the magnetic field optimization effect on the thermal plasma transport and the energetic particle confinement. A higher electron temperature is obtained in the optimized configuration, and the transport analysis suggests a considerable effect of neoclassical transport on the electron heat transport assuming the ion-root level of radial electric field. Also a higher energetic ion distribution of NBI beam ions is observed showing the improvement of the energetic particle confinement. These obtained results support a future reactor design by magnetic field optimization in a non-axisymmetric configuration. (author)

  13. Optimal procedures for home visits — A case study

    Science.gov (United States)

    Alves, Filipe; Fernandes, Florbela P.; Pereira, Ana I.; Fernandes, Adília

    2017-07-01

    In Portugal the population is ageing. Therefore, the provision of health care at patients' home is becoming an important social and health area; this health service is provided by professional teams (usually composed by nurses) of the Health Centers. Nowadays, the scheduling of the visits is made manually. The proposal of this work is to do the scheduling automatically in order to minimize the overall time spent by the professional teams in the visiting activity. In this work the genetic algorithm was used to solve the optimization problem. Some numerical results are presented.

  14. A stepwise procedure for science communication in the field

    Science.gov (United States)

    Nisancioglu, Kerim; Paasche, Øyvind

    2017-04-01

    Communicating and disseminating earth science to laypersons, high-school students and their teachers are becoming increasingly important considering the overwhelming impact human civilization have on the planet. One of the main challenges with this type of dissemination arises from the cross-disciplinary nature of the Earth system as it encompasses anything from cloud physics to the geological evidence of ice ages being played out on millennial time scales. During the last four years we have tested and developed an approach referred to as «Turspor» which can be translated to 'Trail Tracks'. The ambition with "Turspor" is to inspire participants to seek in-depth knowledge relating to observations of features made in the field (glacial moraines, active permafrost, clouds, winds and so forth) as we have come to learn that observations made in the field enhances students capability to grasp the bare essentials related to the phenomena in question. By engaging master and PhD students in the process we create a platform where students can improve their teaching and communicative skills through a stepwise procedure. The initial concept was tested on 35 high school students during the summer of 2012 in the mountainous area of Snøheim on Dovre, Southern Norway. Before the arrival of the high school students, the university students prepared one page written summaries describing relevant geological or meteorological features and trained on how to best disseminate a basic scientific understanding of these. Specific examples were patterned ground caused by permafrost, glacier flour, katabatic winds, and equilibrium line altitude of glaciers. Based on the success of the program over the past 4 years with field trips together with local schools, we are in the process of developing the concept to be offered as a course at the master and PhD level, including a week of training in didactics applied to topics in the geosciences as well as practical training in the field. The

  15. Beyond the drugs : non-pharmacological strategies to optimize procedural care in children

    NARCIS (Netherlands)

    Leroy, Piet L.; Costa, Luciane R.; Emmanouil, Dimitris; van Beukering, Alice; Franck, Linda S.

    2016-01-01

    Purpose of review Painful and/or stressful medical procedures mean a substantial burden for sick children. There is good evidence that procedural comfort can be optimized by a comprehensive comfort-directed policy containing the triad of non-pharmacological strategies (NPS) in all cases, timely or

  16. Optimized procedure for calibration and verification multileaf collimator from Elekta Synergy accelerator

    International Nuclear Information System (INIS)

    Castel Millan, A.; Perellezo Mazon, A.; Fernandez Ibiza, J.; Arnalte Olloquequi, M.; Armengol Martinez, S.; Rodriguez Rey, A.; Guedea Edo, F.

    2011-01-01

    The objective of this work is to design an optimized procedure for calibration and verification of a multileaf collimator used so as to allow the EPID and the image plate in a complementary way, using different processing systems. With this procedure we have two equivalent alternative as the same parameters obtained for the calibration of multileaf Elekta Synergy accelerator.

  17. Generating the optimal magnetic field for magnetic refrigeration

    DEFF Research Database (Denmark)

    Bjørk, Rasmus; Insinga, Andrea Roberto; Smith, Anders

    2016-01-01

    In a magnetic refrigeration device the magnet is the single most expensive component, and therefore it is crucially important to ensure that an effective magnetic field as possible is generated using the least amount of permanent magnets. Here we present a method for calculating the optimal...... remanence distribution for any desired magnetic field. The method is based on the reciprocity theorem, which through the use of virtual magnets can be used to calculate the optimal remanence distribution. Furthermore, we present a method for segmenting a given magnet design that always results...... in the optimal segmentation, for any number of segments specified. These two methods are used to determine the optimal magnet design of a 12-piece, two-pole concentric cylindrical magnet for use in a continuously rotating magnetic refrigeration device....

  18. Using remote sensing images to design optimal field sampling schemes

    CSIR Research Space (South Africa)

    Debba, Pravesh

    2008-08-01

    Full Text Available sampling schemes case studies Optimized field sampling representing the overall distribution of a particular mineral Deriving optimal exploration target zones CONTINUUM REMOVAL for vegetation [13, 27, 46]. The convex hull transform is a method... of normalizing spectra [16, 41]. The convex hull technique is anal- ogous to fitting a rubber band over a spectrum to form a continuum. Figure 5 shows the concept of the convex hull transform. The differ- ence between the hull and the orig- inal spectrum...

  19. Optimization of chemical regeneration procedures of spent activated carbon

    Directory of Open Access Journals (Sweden)

    Naser Ghasemzadeh

    2017-01-01

    Full Text Available The chemical regeneration of granular activated carbon exhausted in a petrochemical wastewater unit was investigated. Gas chromatography and energy-dispersive X-ray spectroscopy demonstrated that spent activated carbon carries large types of organic and inorganic materials. Diverse chemical solvents were adopted in comparison with traditional chemical solvents and regeneration efficiency was investigated for each approach. The optimum procedure and optimum condition including temperature, concentration of solvent, and time were determined. The regenerated activated carbon was used in the adsorption of methylene blue (MB in order to find its regeneration efficiency. The regeneration efficiency can be identified by comparing of amount of MB absorbed by the fresh and regenerated activated carbon. The best acidic regenerator was hydrofluoric acid. The higher the temperature causes the faster desorption rate and consequently, the higher regeneration efficiency. The regeneration efficiency increased by means of an increase in the time of regeneration and solvent concentration, but there was an optimum time and solvent concentration for regeneration. The optimum temperature, solvent concentration and regeneration time obtained was 80 ⁰C, 3 molar and 3 hours, respectively.

  20. Multiple constant multiplication optimizations for field programmable gate arrays

    CERN Document Server

    Kumm, Martin

    2016-01-01

    This work covers field programmable gate array (FPGA)-specific optimizations of circuits computing the multiplication of a variable by several constants, commonly denoted as multiple constant multiplication (MCM). These optimizations focus on low resource usage but high performance. They comprise the use of fast carry-chains in adder-based constant multiplications including ternary (3-input) adders as well as the integration of look-up table-based constant multipliers and embedded multipliers to get the optimal mapping to modern FPGAs. The proposed methods can be used for the efficient implementation of digital filters, discrete transforms and many other circuits in the domain of digital signal processing, communication and image processing. Contents Heuristic and ILP-Based Optimal Solutions for the Pipelined Multiple Constant Multiplication Problem Methods to Integrate Embedded Multipliers, LUT-Based Constant Multipliers and Ternary (3-Input) Adders An Optimized Multiple Constant Multiplication Architecture ...

  1. Field and laboratory procedures used in a soil chronosequence study

    Science.gov (United States)

    Singer, Michael J.; Janitzky, Peter

    1986-01-01

    In 1978, the late Denis Marchand initiated a research project entitled "Soil Correlation and Dating at the U.S. Geological Survey" to determine the usefulness of soils in solving geologic problems. Marchand proposed to establish soil chronosequences that could be dated independently of soil development by using radiometric and other numeric dating methods. In addition, by comparing dated chronosequences in different environments, rates of soil development could be studied and compared among varying climates and mineralogical conditions. The project was fundamental in documenting the value of soils in studies of mapping, correlating, and dating late Cenozoic deposits and in studying soil genesis. All published reports by members of the project are included in the bibliography.The project demanded that methods be adapted or developed to ensure comparability over a wide variation in soil types. Emphasis was placed on obtaining professional expertise and on establishing consistent techniques, especially for the field, laboratory, and data-compilation methods. Since 1978, twelve chronosequences have been sampled and analyzed by members of this project, and methods have been established and used consistently for analysis of the samples.The goals of this report are to:Document the methods used for the study on soil chronosequences,Present the results of tests that were run for precision, accuracy, and effectiveness, andDiscuss our modifications to standard procedures.Many of the methods presented herein are standard and have been reported elsewhere. However, we assume less prior analytical knowledge in our descriptions; thus, the manual should be easy to follow for the inexperienced analyst. Each chapter presents one or more references of the basic principle, an equipment and reagents list, and the detailed procedure. In some chapters this is followed by additional remarks or example calculations.The flow diagram in figure 1 outlines the step-by-step procedures used to

  2. A procedure for multi-objective optimization of tire design parameters

    Directory of Open Access Journals (Sweden)

    Nikola Korunović

    2015-04-01

    Full Text Available The identification of optimal tire design parameters for satisfying different requirements, i.e. tire performance characteristics, plays an essential role in tire design. In order to improve tire performance characteristics, formulation and solving of multi-objective optimization problem must be performed. This paper presents a multi-objective optimization procedure for determination of optimal tire design parameters for simultaneous minimization of strain energy density at two distinctive zones inside the tire. It consists of four main stages: pre-analysis, design of experiment, mathematical modeling and multi-objective optimization. Advantage of the proposed procedure is reflected in the fact that multi-objective optimization is based on the Pareto concept, which enables design engineers to obtain a complete set of optimization solutions and choose a suitable tire design. Furthermore, modeling of the relationships between tire design parameters and objective functions based on multiple regression analysis minimizes computational and modeling effort. The adequacy of the proposed tire design multi-objective optimization procedure has been validated by performing experimental trials based on finite element method.

  3. CTEPP STANDARD OPERATING PROCEDURE FOR CONDUCTING INTERNAL FIELD AUDITS AND QUALITY CONTROL (SOP-2.25)

    Science.gov (United States)

    This SOP describes the method for conducting internal field audits and quality control procedures. Internal field audits will be conducted to ensure the collection of high quality data. Internal field audits will be conducted by Field Auditors (the Field QA Officer and the Field...

  4. Patient Dose Optimization in Fluoroscopically Guided Interventional Procedures. Final Report of a Coordinated Research Project

    International Nuclear Information System (INIS)

    2010-01-01

    In recent years, many surgical procedures have increasingly been replaced by interventional procedures that guide catheters into the arteries under X ray fluoroscopic guidance to perform a variety of operations such as ballooning, embolization, implantation of stents etc. The radiation exposure to patients and staff in such procedures is much higher than in simple radiographic examinations like X ray of chest or abdomen such that radiation induced skin injuries to patients and eye lens opacities among workers have been reported in the 1990's and after. Interventional procedures have grown both in frequency and importance during the last decade. This Coordinated Research Project (CRP) and TECDOC were developed within the International Atomic Energy Agency's (IAEA) framework of statutory responsibility to provide for the worldwide application of the standards for the protection of people against exposure to ionizing radiation. The CRP took place between 2003 and 2005 in six countries, with a view of optimizing the radiation protection of patients undergoing interventional procedures. The Fundamental Safety Principles and the International Basic Safety Standards for Protection against Ionizing Radiation (BSS) issued by the IAEA and co-sponsored by the Food and Agriculture Organization of the United Nations (FAO), the International Labour Organization (ILO), the World Health Organization (WHO), the Pan American Health Organization (PAHO) and the Nuclear Energy Agency (NEA), among others, require the radiation protection of patients undergoing medical exposures through justification of the procedures involved and through optimization. In keeping with its responsibility on the application of standards, the IAEA programme on Radiological Protection of Patients encourages the reduction of patient doses. To facilitate this, it has issued specific advice on the application of the BSS in the field of radiology in Safety Reports Series No. 39 and the three volumes on Radiation

  5. Administrative procedure by stages in the field of environmental law

    International Nuclear Information System (INIS)

    Salis, S.

    1991-01-01

    Governmental decisions concerning large-size projects with an impact on the environment and regional structure always have to cope with particularly complex conflicts of interest. Such projects therefore are not decided or licensed by one single move or act, but there are administrative procedures by stages provided for by the law. The procedure for licensing by stages creates a number of legal problems, especially concerning legal protection against partial licences, and their legal nature and binding effect. The author develops in this book an interdisciplinary system of rules of law and practice for procedure by stages, and presents a proposal for a more uniform approach and legislation. The book thus is a contribution towards in-system harmonisation of the procedural environmental law. (orig.) [de

  6. Optimization of simulated moving bed (SMB) chromatography: a multi-level optimization procedure

    DEFF Research Database (Denmark)

    Jørgensen, Sten Bay; Lim, Young-il

    2004-01-01

    objective functions (productivity and desorbent consumption), employing the standing wave analysis, the true moving bed (TMB) model and the simulated moving bed (SMB) model. The procedure is constructed on a non-worse solution property advancing level by level and its solution does not mean a global optimum...

  7. Optimization of wet digestion procedure of blood and tissue for selenium determination by means of 75Se tracer

    International Nuclear Information System (INIS)

    Holynska, B.; Lipinska, K.

    1977-01-01

    Selenium-75 tracer has been used for optimization of analytical procedure of selenium determination in blood and tissue. Wet digestion procedure and reduction of selenium to its elemental form with tellurium as coprecipitant have been tested. Recovery of selenium obtained with the use of optimized analytical procedure amounts up 95% and precision is equal to 4.2%. (author)

  8. Generalized field-splitting algorithms for optimal IMRT delivery efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Kamath, Srijit [Department of Radiation Oncology, University of Florida, Gainesville, FL (United States); Sahni, Sartaj [Department of Computer and Information Science and Engineering, University of Florida, Gainesville, FL (United States); Li, Jonathan [Department of Radiation Oncology, University of Florida, Gainesville, FL (United States); Ranka, Sanjay [Department of Computer and Information Science and Engineering, University of Florida, Gainesville, FL (United States); Palta, Jatinder [Department of Radiation Oncology, University of Florida, Gainesville, FL (United States)

    2007-09-21

    Intensity-modulated radiation therapy (IMRT) uses radiation beams of varying intensities to deliver varying doses of radiation to different areas of the tissue. The use of IMRT has allowed the delivery of higher doses of radiation to the tumor and lower doses to the surrounding healthy tissue. It is not uncommon for head and neck tumors, for example, to have large treatment widths that are not deliverable using a single field. In such cases, the intensity matrix generated by the optimizer needs to be split into two or three matrices, each of which may be delivered using a single field. Existing field-splitting algorithms used the pre-specified arbitrary split line or region where the intensity matrix is split along a column, i.e., all rows of the matrix are split along the same column (with or without the overlapping of split fields, i.e., feathering). If three fields result, then the two splits are along the same two columns for all rows. In this paper we study the problem of splitting a large field into two or three subfields with the field width as the only constraint, allowing for an arbitrary overlap of the split fields, so that the total MU efficiency of delivering the split fields is maximized. Proof of optimality is provided for the proposed algorithm. An average decrease of 18.8% is found in the total MUs when compared to the split generated by a commercial treatment planning system and that of 10% is found in the total MUs when compared to the split generated by our previously published algorithm. For more information on this article, see medicalphysicsweb.org.

  9. An Optimal Electric Dipole Antenna Model and Its Field Propagation

    Directory of Open Access Journals (Sweden)

    Yidong Xu

    2016-01-01

    Full Text Available An optimal electric dipole antennas model is presented and analyzed, based on the hemispherical grounding equivalent model and the superposition principle. The paper also presents a full-wave electromagnetic simulation for the electromagnetic field propagation in layered conducting medium, which is excited by the horizontal electric dipole antennas. Optimum frequency for field transmission in different depth is carried out and verified by the experimental results in comparison with previously reported simulation over a digital wireless Through-The-Earth communication system. The experimental results demonstrate that the dipole antenna grounding impedance and the output power can be efficiently reduced by using the optimal electric dipole antenna model and operating at the optimum frequency in a vertical transmission depth up to 300 m beneath the surface of the earth.

  10. Optimization Design of Bipolar Plate Flow Field in PEM Stack

    Science.gov (United States)

    Wen, Ming; He, Kanghao; Li, Peilong; Yang, Lei; Deng, Li; Jiang, Fei; Yao, Yong

    2017-12-01

    A new design of bipolar plate flow field in proton exchange membrane (PEM) stack was presented to develop a high-performance transfer efficiency of the two-phase flow. Two different flow fields were studied by using numerical simulations and the performance of the flow fields was presented. the hydrodynamic properties include pressure gap between inlet and outlet, the Reynold’s number of the two types were compared based on the Navier-Stokes equations. Computer aided optimization software was implemented in the design of experiments of the preferable flow field. The design of experiments (DOE) for the favorable concept was carried out to study the hydrodynamic properties when changing the design parameters of the bipolar plate.

  11. Optimized molecular reconstruction procedure combining hybrid reverse Monte Carlo and molecular dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Bousige, Colin; Boţan, Alexandru; Coasne, Benoît, E-mail: coasne@mit.edu [Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States); UMI 3466 CNRS-MIT, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States); Ulm, Franz-Josef [Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States); Pellenq, Roland J.-M. [Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States); UMI 3466 CNRS-MIT, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States); CINaM, CNRS/Aix Marseille Université, Campus de Luminy, 13288 Marseille Cedex 09 (France)

    2015-03-21

    We report an efficient atom-scale reconstruction method that consists of combining the Hybrid Reverse Monte Carlo algorithm (HRMC) with Molecular Dynamics (MD) in the framework of a simulated annealing technique. In the spirit of the experimentally constrained molecular relaxation technique [Biswas et al., Phys. Rev. B 69, 195207 (2004)], this modified procedure offers a refined strategy in the field of reconstruction techniques, with special interest for heterogeneous and disordered solids such as amorphous porous materials. While the HRMC method generates physical structures, thanks to the use of energy penalties, the combination with MD makes the method at least one order of magnitude faster than HRMC simulations to obtain structures of similar quality. Furthermore, in order to ensure the transferability of this technique, we provide rational arguments to select the various input parameters such as the relative weight ω of the energy penalty with respect to the structure optimization. By applying the method to disordered porous carbons, we show that adsorption properties provide data to test the global texture of the reconstructed sample but are only weakly sensitive to the presence of defects. In contrast, the vibrational properties such as the phonon density of states are found to be very sensitive to the local structure of the sample.

  12. Virtual reality simulation for the optimization of endovascular procedures: current perspectives

    Directory of Open Access Journals (Sweden)

    Rudarakanchana N

    2015-03-01

    Full Text Available Nung Rudarakanchana,1 Isabelle Van Herzeele,2 Liesbeth Desender,2 Nicholas JW Cheshire1 1Department of Surgery, Imperial College London, London, UK; 2Department of Thoracic and Vascular Surgery, Ghent University Hospital, Ghent, BelgiumOn behalf of EVEREST (European Virtual reality Endovascular RESearch TeamAbstract: Endovascular technologies are rapidly evolving, often requiring coordination and cooperation between clinicians and technicians from diverse specialties. These multidisciplinary interactions lead to challenges that are reflected in the high rate of errors occurring during endovascular procedures. Endovascular virtual reality (VR simulation has evolved from simple benchtop devices to full physic simulators with advanced haptics and dynamic imaging and physiological controls. The latest developments in this field include the use of fully immersive simulated hybrid angiosuites to train whole endovascular teams in crisis resource management and novel technologies that enable practitioners to build VR simulations based on patient-specific anatomy. As our understanding of the skills, both technical and nontechnical, required for optimal endovascular performance improves, the requisite tools for objective assessment of these skills are being developed and will further enable the use of VR simulation in the training and assessment of endovascular interventionalists and their entire teams. Simulation training that allows deliberate practice without danger to patients may be key to bridging the gap between new endovascular technology and improved patient outcomes.Keywords: virtual reality, simulation, endovascular, aneurysm

  13. Evaluation of relevant information for optimal reflector modeling through data assimilation procedures

    International Nuclear Information System (INIS)

    Argaud, J.P.; Bouriquet, B.; Clerc, T.; Lucet-Sanchez, F.; Poncot, A.

    2015-01-01

    The goal of this study is to look after the amount of information that is mandatory to get a relevant parameters optimisation by data assimilation for physical models in neutronic diffusion calculations, and to determine what is the best information to reach the optimum of accuracy at the cheapest cost. To evaluate the quality of the optimisation, we study the covariance matrix that represents the accuracy of the optimised parameter. This matrix is a classical output of the data assimilation procedure, and it is the main information about accuracy and sensitivity of the parameter optimal determination. We present some results collected in the field of neutronic simulation for PWR type reactor. We seek to optimise the reflector parameters that characterise the neutronic reflector surrounding the whole reactive core. On the basis of the configuration studies, it has been shown that with data assimilation we can determine a global strategy to optimise the quality of the result with respect to the amount of information provided. The consequence of this is a cost reduction in terms of measurement and/or computing time with respect to the basic approach. Another result is that using multi-campaign data rather data from a unique campaign significantly improves the efficiency of parameters optimisation

  14. Virtual reality simulation for the optimization of endovascular procedures: current perspectives.

    Science.gov (United States)

    Rudarakanchana, Nung; Van Herzeele, Isabelle; Desender, Liesbeth; Cheshire, Nicholas J W

    2015-01-01

    Endovascular technologies are rapidly evolving, often requiring coordination and cooperation between clinicians and technicians from diverse specialties. These multidisciplinary interactions lead to challenges that are reflected in the high rate of errors occurring during endovascular procedures. Endovascular virtual reality (VR) simulation has evolved from simple benchtop devices to full physic simulators with advanced haptics and dynamic imaging and physiological controls. The latest developments in this field include the use of fully immersive simulated hybrid angiosuites to train whole endovascular teams in crisis resource management and novel technologies that enable practitioners to build VR simulations based on patient-specific anatomy. As our understanding of the skills, both technical and nontechnical, required for optimal endovascular performance improves, the requisite tools for objective assessment of these skills are being developed and will further enable the use of VR simulation in the training and assessment of endovascular interventionalists and their entire teams. Simulation training that allows deliberate practice without danger to patients may be key to bridging the gap between new endovascular technology and improved patient outcomes.

  15. Using remotely-sensed data for optimal field sampling

    CSIR Research Space (South Africa)

    Debba, Pravesh

    2008-09-01

    Full Text Available M B E R 2 0 0 8 15 USING REMOTELY- SENSED DATA FOR OPTIMAL FIELD SAMPLING BY DR PRAVESH DEBBA STATISTICS IS THE SCIENCE pertaining to the collection, summary, analysis, interpretation and presentation of data. It is often impractical... studies are: where to sample, what to sample and how many samples to obtain. Conventional sampling techniques are not always suitable in environmental studies and scientists have explored the use of remotely-sensed data as ancillary information to aid...

  16. Enhanced flow field visualization using a flexible animation procedure

    International Nuclear Information System (INIS)

    Marconi, F.; Moretti, G.; Englund, D.C.

    1989-01-01

    A flexible and powerful procedure for transposing computer-generated images onto video tape is used in flowfield visualization. The result is animated sequences which can be used very effectively in the study of both steady and unsteady flows. The key to the procedure is the fact that the images (i.e., frames) of the animated sequence are recorded on the video tapes one at a time after they are created. Thus, the need for a mass storage system is eliminated because after a frame is recorded it is discarded. 7 references

  17. First principles molecular dynamics without self-consistent field optimization

    International Nuclear Information System (INIS)

    Souvatzis, Petros; Niklasson, Anders M. N.

    2014-01-01

    We present a first principles molecular dynamics approach that is based on time-reversible extended Lagrangian Born-Oppenheimer molecular dynamics [A. M. N. Niklasson, Phys. Rev. Lett. 100, 123004 (2008)] in the limit of vanishing self-consistent field optimization. The optimization-free dynamics keeps the computational cost to a minimum and typically provides molecular trajectories that closely follow the exact Born-Oppenheimer potential energy surface. Only one single diagonalization and Hamiltonian (or Fockian) construction are required in each integration time step. The proposed dynamics is derived for a general free-energy potential surface valid at finite electronic temperatures within hybrid density functional theory. Even in the event of irregular functional behavior that may cause a dynamical instability, the optimization-free limit represents a natural starting guess for force calculations that may require a more elaborate iterative electronic ground state optimization. Our optimization-free dynamics thus represents a flexible theoretical framework for a broad and general class of ab initio molecular dynamics simulations

  18. Optimal decision procedures for satisfiability in fragments of alternating-time temporal logics

    DEFF Research Database (Denmark)

    Goranko, Valentin; Vester, Steen

    2014-01-01

    We consider several natural fragments of the alternating-time temporal logics ATL*and ATL with restrictions on the nesting between temporal operators and strate-gicquantifiers. We develop optimal decision procedures for satisfiability in these fragments, showing that they have much lower complexi...

  19. Package of procedures for the decision of optimization tasks by the method of branches and borders

    OpenAIRE

    Nestor, Natalia

    2012-01-01

    The practical aspects of realization of method of branches and borders are examined. The structure of package of procedures is pointed for implementation of basic operations at the decision of optimization tasks. A package is projected as a programmatic kernel which can be used for the various tasks of exhaustive search with returning.

  20. Structural optimization of an alternate design for the Space Shuttle solid rocket booster field joint

    Science.gov (United States)

    Barthelemy, Jean-Francois M.; Rogers, James L., Jr.; Chang, Kwan J.

    1987-01-01

    A structural optimization procedure is used to determine the shape of an alternate design for the Shuttle's solid rocket booster field joint. In contrast to the tang and clevis design of the existing joint, this alternate design consists of two flanges bolted together. Configurations with 150 studs of 1 1/8 in diameter and 135 studs of 1 3/16 in diameter are considered. Using a nonlinear programming procedure, the joint weight is minimized under constraints on either von Mises or maximum normal stresses, joint opening and geometry. The procedure solves the design problem by replacing it by a sequence of approximate (convex) subproblems; the pattern of contact between the joint halves is determined every few cycles by a nonlinear displacement analysis. The minimum weight design has 135 studs of 1 3/16 in diameter and is designed under constraints on normal stresses. It weighs 1144 lb per joint more than the current tang and clevis design.

  1. Image-guided spinal injection procedures in open high-field MRI with vertical field orientation: feasibility and technical features

    Energy Technology Data Exchange (ETDEWEB)

    Streitparth, F.; Walter, T.; Wonneberger, U.; Wagner, M.; Hermann, K.G.; Hamm, B.; Teichgraeber, U. [Charite, Humboldt-Universitaet zu Berlin, Department of Radiology, Berlin (Germany); Chopra, S. [Charite-Universitaetsmedizin Berlin, Campus Virchow Klinikum, Department of General, Visceral, and Transplantation Surgery, Berlin (Germany); Wichlas, F. [Charite-Universitaetsmedizin Berlin, Campus Virchow Klinikum, Center for Musculoskeletal Surgery, Berlin (Germany)

    2010-02-15

    We prospectively evaluated the feasibility and technical features of MR-guided lumbosacral injection procedures in open high-field MRI at 1.0 T. In a CuSO{sub 4}.5H{sub 2}O phantom and five human cadaveric spines, fluoroscopy sequences (proton-density-weighted turbo spin-echo (PDw TSE), T1w TSE, T2w TSE; balanced steady-state free precession (bSSFP), T1w gradient echo (GE), T2w GE) were evaluated using two MRI-compatible 20-G Chiba-type needles. Artefacts were analysed by varying needle orientation to B{sub 0}, frequency-encoding direction and slice orientation. Image quality was described using the contrast-to-noise ratio (CNR). Subsequently, a total of 183 MR-guided nerve root (107), facet (53) and sacroiliac joint (23) injections were performed in 53 patients. In vitro, PDw TSE sequence yielded the best needle-tissue contrasts (CNR = 45, 18, 15, 9, and 8 for needle vs. fat, muscle, root, bone and sclerosis, respectively) and optimal artefact sizes (width and tip shift less than 5 mm). In vivo, PDw TSE sequence was sufficient in all cases. The acquisition time of 2 s facilitated near-real-time MRI guidance. Drug delivery was technically successful in 100% (107/107), 87% (46/53) and 87% (20/23) of nerve root, facet and sacroiliac joint injections, respectively. No major complications occurred. The mean procedure time was 29 min (range 19-67 min). MR-guided spinal injections in open high-field MRI are feasible and accurate using fast TSE sequence designs. (orig.)

  2. The optimal use of contrast agents at high field MRI

    International Nuclear Information System (INIS)

    Trattnig, Siegfried; Pinker, Kathia; Ba-Ssalamah, Ahmed; Noebauer-Huhmann, Iris-Melanie

    2006-01-01

    The intravenous administration of a standard dose of conventional gadolinium-based contrast agents produces higher contrast between the tumor and normal brain at 3.0 Tesla (T) than at 1.5 T, which allows reducing the dose to half of the standard one to produce similar contrast at 3.0 T compared to 1.5 T. The assessment of cumulative triple-dose 3.0 T images obtained the best results in the detection of brain metastases compared to other sequences. The contrast agent dose for dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging at 3.0 T can be reduced to 0.1 mmol compared to 0.2 mmol at 1.5 T due to the increased susceptibility effects at higher magnetic field strengths. Contrast agent application makes susceptibility-weighted imaging (SWI) at 3.0 T clinically attractive, with an increase in spatial resolution within the same scan time. Whereas a double dose of conventional gadolinium-based contrast agents was optimal in SWI with respect to sensitivity and image quality, a standard dose of gadobenate dimeglumine, which has a two-fold higher T1-relaxivity in blood, produced the same effect. For MR-arthrography, optimized concentrations of gadolinium-based contrast agents are similar at 3.0 and 1.5 T. In summary, high field MRI requires the optimization of the contrast agent dose in different clinical applications. (orig.)

  3. Pareto-Optimization of HTS CICC for High-Current Applications in Self-Field

    Directory of Open Access Journals (Sweden)

    Giordano Tomassetti

    2018-01-01

    Full Text Available The ENEA superconductivity laboratory developed a novel design for Cable-in-Conduit Conductors (CICCs comprised of stacks of 2nd-generation REBCO coated conductors. In its original version, the cable was made up of 150 HTS tapes distributed in five slots, twisted along an aluminum core. In this work, taking advantage of a 2D finite element model, able to estimate the cable’s current distribution in the cross-section, a multiobjective optimization procedure was implemented. The aim of optimization was to simultaneously maximize both engineering current density and total current flowing inside the tapes when operating in self-field, by varying the cross-section layout. Since the optimization process involved both integer and real geometrical variables, the choice of an evolutionary search algorithm was strictly necessary. The use of an evolutionary algorithm in the frame of a multiple objective optimization made it an obliged choice to numerically approach the problem using a nonstandard fast-converging optimization algorithm. By means of this algorithm, the Pareto frontiers for the different configurations were calculated, providing a powerful tool for the designer to achieve the desired preliminary operating conditions in terms of engineering current density and/or total current, depending on the specific application field, that is, power transmission cable and bus bar systems.

  4. Optimized design of micromachined electric field mills to maximize electrostatic field sensitivity

    OpenAIRE

    Zhou, Yu; Shafai, Cyrus

    2016-01-01

    This paper describes the design optimization of a micromachined electric field mill, in relation to maximizing its output signal. The cases studied are for a perforated electrically grounded shutter vibrating laterally over sensing electrodes. It is shown that when modeling the output signal of the sensor, the differential charge on the sense electrodes when exposed to vs. visibly shielded from the incident electric field must be considered. Parametric studies of device dimensions show that t...

  5. Subgrid-scale scalar flux modelling based on optimal estimation theory and machine-learning procedures

    Science.gov (United States)

    Vollant, A.; Balarac, G.; Corre, C.

    2017-09-01

    New procedures are explored for the development of models in the context of large eddy simulation (LES) of a passive scalar. They rely on the combination of the optimal estimator theory with machine-learning algorithms. The concept of optimal estimator allows to identify the most accurate set of parameters to be used when deriving a model. The model itself can then be defined by training an artificial neural network (ANN) on a database derived from the filtering of direct numerical simulation (DNS) results. This procedure leads to a subgrid scale model displaying good structural performance, which allows to perform LESs very close to the filtered DNS results. However, this first procedure does not control the functional performance so that the model can fail when the flow configuration differs from the training database. Another procedure is then proposed, where the model functional form is imposed and the ANN used only to define the model coefficients. The training step is a bi-objective optimisation in order to control both structural and functional performances. The model derived from this second procedure proves to be more robust. It also provides stable LESs for a turbulent plane jet flow configuration very far from the training database but over-estimates the mixing process in that case.

  6. Radiological protection in coronary procedures. Is it sufficient with the practices optimizations?

    International Nuclear Information System (INIS)

    Cotelo, Elena D.

    2001-01-01

    The number of percutaneous transluminal coronary procedures (PTCA) per million inhabitants in Uruguay is similar to the one obtained in developed countries. Between 1995 and 1999, PTCA procedures increased by 86 %. Despite the 'Fondo Nacional de Recursos' finances the Interventional Cardiology (IC) procedures of 90 % inhabitants, the number of IC procedures on people of public hospital is lower than that on people from private hospitals. All the 6 IC facilities are in the capital of the country. The number of IC procedures increases while decrease s the distance between the hospital and the capital. This study also shows that no one facility performs quality control tests, the 50% of the X-ray equipment is more than 10 years and, the IC staff does not have Radiation Protection education. We conclude that it is necessary to establishing as soon as possible, Quality Assurance Programmes. Despite the objective of this work was to obtain information to optimize the IC procedures, results shows that it is necessary to include the Principle of Justification of the procedures in Radiation Protection education for the IC staff. (author)

  7. An optimized field coverage planning approach for navigation of agricultural robots in fields involving obstacle areas

    DEFF Research Database (Denmark)

    Hameed, Ibahim; Bochtis, D.; Sørensen, C.A.

    2013-01-01

    -field obstacle areas, the headland paths generation for the field and each obstacle area, the implementation of a genetic algorithm to optimize the sequence that the field robot vehicle will follow to visit the blocks, and an algorithmically generation of the task sequences derived from the farmer practices......Technological advances combined with the demand of cost efficiency and environmental considerations lead farmers to review their practices towards the adoption of new managerial approaches including enhanced automation. The application of field robots is one of the most promising advances among....... This approach has proven that it is possible to capture the practices of farmers and embed these practices in an algorithmic description providing a complete field area coverage plan in a form prepared for execution by the navigation system of a field robot....

  8. The Mechanical Design Optimization of a High Field HTS Solenoid

    Energy Technology Data Exchange (ETDEWEB)

    Lalitha, SL; Gupta, RC

    2015-06-01

    This paper describes the conceptual design optimization of a large aperture, high field (24 T at 4 K) solenoid for a 1.7 MJ superconducting magnetic energy storage device. The magnet is designed to be built entirely of second generation (2G) high temperature superconductor tape with excellent electrical and mechanical properties at the cryogenic temperatures. The critical parameters that govern the magnet performance are examined in detail through a multiphysics approach using ANSYS software. The analysis results formed the basis for the performance specification as well as the construction of the magnet.

  9. An analytic approach to optimize tidal turbine fields

    Science.gov (United States)

    Pelz, P.; Metzler, M.

    2013-12-01

    Motivated by global warming due to CO2-emission various technologies for harvesting of energy from renewable sources are developed. Hydrokinetic turbines get applied to surface watercourse or tidal flow to gain electrical energy. Since the available power for hydrokinetic turbines is proportional to the projected cross section area, fields of turbines are installed to scale shaft power. Each hydrokinetic turbine of a field can be considered as a disk actuator. In [1], the first author derives the optimal operation point for hydropower in an open-channel. The present paper concerns about a 0-dimensional model of a disk-actuator in an open-channel flow with bypass, as a special case of [1]. Based on the energy equation, the continuity equation and the momentum balance an analytical approach is made to calculate the coefficient of performance for hydrokinetic turbines with bypass flow as function of the turbine head and the ratio of turbine width to channel width.

  10. Procedures in field systems for collecting and demulsifying crude oils

    Energy Technology Data Exchange (ETDEWEB)

    Vakhitov, G G; Graifer, V I; Tronov, V P; Zakirov, I G

    1969-01-01

    This microscopic study of crude oil emulsification and demulsification showed that the sooner an emulsion is chemically treated, the less its stability. This finding led to the practice of adding demulsifiers to the crude oil in pipelines. This method of demulsification is now used in Romashkino, Bablinsk, and Elkhovs fields. By this early addition of a chemical, the tendency of the pipeline to form stable, highly viscous emulsions is reduced. This treatment also facilitates separation of water from oil in storage tanks. Repeated tests have shown that pipeline demulsification is a highly effective and economic process. This method reduces crude oil dewatering costs by several hundred percent.

  11. Interpretation, compilation and field verification procedures in the CARETS project

    Science.gov (United States)

    Alexander, Robert H.; De Forth, Peter W.; Fitzpatrick, Katherine A.; Lins, Harry F.; McGinty, Herbert K.

    1975-01-01

    The production of the CARETS map data base involved the development of a series of procedures for interpreting, compiling, and verifying data obtained from remote sensor sources. Level II land use mapping from high-altitude aircraft photography at a scale of 1:100,000 required production of a photomosaic mapping base for each of the 48, 50 x 50 km sheets, and the interpretation and coding of land use polygons on drafting film overlays. CARETS researchers also produced a series of 1970 to 1972 land use change overlays, using the 1970 land use maps and 1972 high-altitude aircraft photography. To enhance the value of the land use sheets, researchers compiled series of overlays showing cultural features, county boundaries and census tracts, surface geology, and drainage basins. In producing Level I land use maps from Landsat imagery, at a scale of 1:250,000, interpreters overlaid drafting film directly on Landsat color composite transparencies and interpreted on the film. They found that such interpretation involves pattern and spectral signature recognition. In studies using Landsat imagery, interpreters identified numerous areas of change but also identified extensive areas of "false change," where Landsat spectral signatures but not land use had changed.

  12. Procedures for finding optimal layouts of vehicle components with respect to durability

    Energy Technology Data Exchange (ETDEWEB)

    Eschenauer, H.A.; Idelberger, H. [Univ. of Siegen (Germany); Bieker, G.; Rottler, A. [Bombardier, Siegen-Netphen (Germany); Weinert, M. [Ford Motor Comp., Cologne (Germany)

    2007-07-01

    When designing complete systems or system components, it is of vital importance for the manufacturers to optimally fulfill the continuously increasing demands pertaining to safety, durability, reduction of energy consumption, noise reduction, improvement of comfort, accuracy, etc. This applies to all types of traffic and transportation systems like rail vehicles, automobiles, airplanes and ships. By combining structural analysis and simulation methods with optimization algorithms, required specifications can be met faster and more reliably, and hence the production development cycles can be substantially reduced. This paper shall give an overview on results of a method with the features of a damage approximation as precisely as possible on the one hand and, on the other hand, a load-time history with few different load cycles so that a nonlinear calculation can be performed in the shortest possible time. Simulations with rigidly and elastically modeled components like bogie frames or carbodies show that depending on the type of modeling substantial differences may occur with respect to dynamic behavior and the interaction quantity between the bodies. This aspect has to be taken into consideration for quantitatively sufficient fatigue strength and durability calculation. Mathematical optimization procedures are in general an efficient tool to guarantee the optimal fulfillment of all required design objectives and constraints in all stages of the design process. Some of the procedures are illustrated at two examples (bogie frame, carbody). (orig.)

  13. An automatic procedure for optimizing fuel loading in consideration of the effect of burnup nonuniformity in assembly

    International Nuclear Information System (INIS)

    Wang Guoli.

    1988-01-01

    The effect of burnup nonuniformity across the assembly on optimizing fuel loading in core is investigated. Some new rules which can be used for optimizing fuel loading in the core are proposed. New automatic procedure for optimizing fuel loading in the core is described

  14. Field screening procedures for determining the presence of volatile organic compounds in soil

    International Nuclear Information System (INIS)

    Crockett, A.B.; DeHaan, M.S.

    1991-01-01

    Many field screening procedures have been used to detect the presence of volatile organic compounds (VOC) in soils but almost none have been documented and verified. Users of these procedures have not really known whether their objectives in screening were met. A reliable VOC screening procedure could significantly reduce the number of samples currently being submitted to laboratories, thereby reducing costs and improving site characterization. The Environmental Protection Agency's Environmental Monitoring Systems Laboratory in Las Vegas (EMSL-LV) has therefore sponsored a research effort to evaluate and improve headspace methods for screening soils for VOC in the field. The research involved comparing several extraction procedures using soils from actual waste sites, and determining the agitation and mixing necessary to achieve equilibrium. Headspace was analyzed using a relatively simple portable gas chromatograph with a short column. The results were variable and show that several procedures should be attempted and the results evaluated before selecting a screening procedure. 10 refs., 6 tabs

  15. Magnetic field models and their application in optimal magnetic divertor design

    Energy Technology Data Exchange (ETDEWEB)

    Blommaert, M.; Reiter, D. [Institute of Energy and Climate Research (IEK-4), FZ Juelich GmbH, Juelich (Germany); Baelmans, M. [KU Leuven, Department of Mechanical Engineering, Leuven (Belgium); Heumann, H. [TEAM CASTOR, INRIA Sophia Antipolis (France); Marandet, Y.; Bufferand, H. [Aix-Marseille Universite, CNRS, PIIM, Marseille (France); Gauger, N.R. [TU Kaiserslautern, Chair for Scientific Computing, Kaiserslautern (Germany)

    2016-08-15

    In recent automated design studies, optimal design methods were introduced to successfully reduce the often excessive heat loads that threaten the divertor target surface. To this end, divertor coils were controlled to improve the magnetic configuration. The divertor performance was then evaluated using a plasma edge transport code and a ''vacuum approach'' for magnetic field perturbations. Recent integration of a free boundary equilibrium (FBE) solver allows to assess the validity of the vacuum approach. It is found that the absence of plasma response currents significantly limits the accuracy of the vacuum approach. Therefore, the optimal magnetic divertor design procedure is extended to incorporate full FBE solutions. The novel procedure is applied to obtain first results for the new WEST (Tungsten Environment in Steady-state Tokamak) divertor currently under construction in the Tore Supra tokamak at CEA (Commissariat a l'Energie Atomique, France). The sensitivities and the related divertor optimization paths are strongly affected by the extension of the magnetic model. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Rigorous force field optimization principles based on statistical distance minimization

    Energy Technology Data Exchange (ETDEWEB)

    Vlcek, Lukas, E-mail: vlcekl1@ornl.gov [Chemical Sciences Division, Geochemistry & Interfacial Sciences Group, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6110 (United States); Joint Institute for Computational Sciences, University of Tennessee, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6173 (United States); Chialvo, Ariel A. [Chemical Sciences Division, Geochemistry & Interfacial Sciences Group, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6110 (United States)

    2015-10-14

    We use the concept of statistical distance to define a measure of distinguishability between a pair of statistical mechanical systems, i.e., a model and its target, and show that its minimization leads to general convergence of the model’s static measurable properties to those of the target. We exploit this feature to define a rigorous basis for the development of accurate and robust effective molecular force fields that are inherently compatible with coarse-grained experimental data. The new model optimization principles and their efficient implementation are illustrated through selected examples, whose outcome demonstrates the higher robustness and predictive accuracy of the approach compared to other currently used methods, such as force matching and relative entropy minimization. We also discuss relations between the newly developed principles and established thermodynamic concepts, which include the Gibbs-Bogoliubov inequality and the thermodynamic length.

  17. Optimization of temperature field of tobacco heat shrink machine

    Science.gov (United States)

    Yang, Xudong; Yang, Hai; Sun, Dong; Xu, Mingyang

    2018-06-01

    A company currently shrinking machine in the course of the film shrinkage is not compact, uneven temperature, resulting in poor quality of the shrinkage of the surface film. To solve this problem, the simulation and optimization of the temperature field are performed by using the k-epsilon turbulence model and the MRF model in fluent. The simulation results show that after the mesh screen structure is installed at the suction inlet of the centrifugal fan, the suction resistance of the fan can be increased and the eddy current intensity caused by the high-speed rotation of the fan can be improved, so that the internal temperature continuity of the heat shrinkable machine is Stronger.

  18. What SCADA systems can offer to optimize field operations

    International Nuclear Information System (INIS)

    McLean, D.J.

    1997-01-01

    A new technology developed by Kenomic Controls Ltd. of Calgary was designed to solve some of the problems associated with producing gas wells with high gas to liquids ratios. The rationale and the system architecture of the SCADA (Supervisory Control and Data Acquisition) system were described. The most common application of SCADA is the Electronic Flow Measurement (EFM) installation using a solar or thermo-electric generator as a power source for the local electronics. Benefits that the SCADA system can provide to producing fields such as increased revenue, decreased operating costs, decreased fixed capital and working capital requirements, the planning and implementation strategies for SCADA were outlined. A case history of a gas well production optimization system in the Pierceland area of northwest Saskatchewan was provided as an illustrative example. 9 figs

  19. Optimization of lift gas allocation in a gas lifted oil field as non-linear optimization problem

    Directory of Open Access Journals (Sweden)

    Roshan Sharma

    2012-01-01

    Full Text Available Proper allocation and distribution of lift gas is necessary for maximizing total oil production from a field with gas lifted oil wells. When the supply of the lift gas is limited, the total available gas should be optimally distributed among the oil wells of the field such that the total production of oil from the field is maximized. This paper describes a non-linear optimization problem with constraints associated with the optimal distribution of the lift gas. A non-linear objective function is developed using a simple dynamic model of the oil field where the decision variables represent the lift gas flow rate set points of each oil well of the field. The lift gas optimization problem is solved using the emph'fmincon' solver found in MATLAB. As an alternative and for verification, hill climbing method is utilized for solving the optimization problem. Using both of these methods, it has been shown that after optimization, the total oil production is increased by about 4. For multiple oil wells sharing lift gas from a common source, a cascade control strategy along with a nonlinear steady state optimizer behaves as a self-optimizing control structure when the total supply of lift gas is assumed to be the only input disturbance present in the process. Simulation results show that repeated optimization performed after the first time optimization under the presence of the input disturbance has no effect in the total oil production.

  20. Optimized in vitro procedure for assessing the cytocompatibility of magnesium-based biomaterials.

    Science.gov (United States)

    Jung, Ole; Smeets, Ralf; Porchetta, Dario; Kopp, Alexander; Ptock, Christoph; Müller, Ute; Heiland, Max; Schwade, Max; Behr, Björn; Kröger, Nadja; Kluwe, Lan; Hanken, Henning; Hartjen, Philip

    2015-09-01

    Magnesium (Mg) is a promising biomaterial for degradable implant applications that has been extensively studied in vitro and in vivo in recent years. In this study, we developed a procedure that allows an optimized and uniform in vitro assessment of the cytocompatibility of Mg-based materials while respecting the standard protocol DIN EN ISO 10993-5:2009. The mouse fibroblast line L-929 was chosen as the preferred assay cell line and MEM supplemented with 10% FCS, penicillin/streptomycin and 4mM l-glutamine as the favored assay medium. The procedure consists of (1) an indirect assessment of effects of soluble Mg corrosion products in material extracts and (2) a direct assessment of the surface compatibility in terms of cell attachment and cytotoxicity originating from active corrosion processes. The indirect assessment allows the quantification of cell-proliferation (BrdU-assay), viability (XTT-assay) as well as cytotoxicity (LDH-assay) of the mouse fibroblasts incubated with material extracts. Direct assessment visualizes cells attached to the test materials by means of live-dead staining. The colorimetric assays and the visual evaluation complement each other and the combination of both provides an optimized and simple procedure for assessing the cytocompatibility of Mg-based biomaterials in vitro. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  1. Design Procedure for High-Speed PM Motors Aided by Optimization Algorithms

    Directory of Open Access Journals (Sweden)

    Francesco Cupertino

    2018-02-01

    Full Text Available This paper considers the electromagnetic and structural co-design of superficial permanent magnet synchronous machines for high-speed applications, with the aid of a Pareto optimization procedure. The aim of this work is to present a design procedure for the afore-mentioned machines that relies on the combined used of optimization algorithms and finite element analysis. The proposed approach allows easy analysis of the results and a lowering of the computational burden. The proposed design method is presented through a practical example starting from the specifications of an aeronautical actuator. The design procedure is based on static finite element simulations for electromagnetic analysis and on analytical formulas for structural design. The final results are validated through detailed transient finite element analysis to verify both electromagnetic and structural performance. The step-by-step presentation of the proposed design methodology allows the reader to easily adapt it to different specifications. Finally, a comparison between a distributed-winding (24 slots and a concentrated-winding (6 slots machine is presented demonstrating the advantages of the former winding arrangement for high-speed applications.

  2. Systematic and efficient side chain optimization for molecular docking using a cheapest-path procedure.

    Science.gov (United States)

    Schumann, Marcel; Armen, Roger S

    2013-05-30

    Molecular docking of small-molecules is an important procedure for computer-aided drug design. Modeling receptor side chain flexibility is often important or even crucial, as it allows the receptor to adopt new conformations as induced by ligand binding. However, the accurate and efficient incorporation of receptor side chain flexibility has proven to be a challenge due to the huge computational complexity required to adequately address this problem. Here we describe a new docking approach with a very fast, graph-based optimization algorithm for assignment of the near-optimal set of residue rotamers. We extensively validate our approach using the 40 DUD target benchmarks commonly used to assess virtual screening performance and demonstrate a large improvement using the developed side chain optimization over rigid receptor docking (average ROC AUC of 0.693 vs. 0.623). Compared to numerous benchmarks, the overall performance is better than nearly all other commonly used procedures. Furthermore, we provide a detailed analysis of the level of receptor flexibility observed in docking results for different classes of residues and elucidate potential avenues for further improvement. Copyright © 2013 Wiley Periodicals, Inc.

  3. A materials selection procedure for sandwiched beams via parametric optimization with applications in automotive industry

    International Nuclear Information System (INIS)

    Aly, Mohamed F.; Hamza, Karim T.; Farag, Mahmoud M.

    2014-01-01

    Highlights: • Sandwich panels optimization model. • Sandwich panels design procedure. • Study of sandwich panels for automotive vehicle flooring. • Study of sandwich panels for truck cabin exterior. - Abstract: The future of automotive industry faces many challenges in meeting increasingly strict restrictions on emissions, energy usage and recyclability of components alongside the need to maintain cost competiveness. Weight reduction through innovative design of components and proper material selection can have profound impact towards attaining such goals since most of the lifecycle energy usage occurs during the operation phase of a vehicle. In electric and hybrid vehicles, weight reduction has another important effect of extending the electric mode driving range between stops or gasoline mode. This paper adopts parametric models for design optimization and material selection of sandwich panels with the objective of weight and cost minimization subject to structural integrity constraints such as strength, stiffness and buckling resistance. The proposed design procedure employs a pre-compiled library of candidate sandwich panel material combinations, for which optimization of the layered thicknesses is conducted and the best one is reported. Example demonstration studies from the automotive industry are presented for the replacement of Aluminum and Steel panels with polypropylene-filled sandwich panel alternatives

  4. Automated procedure for selection of optimal refueling policies for light water reactors

    International Nuclear Information System (INIS)

    Lin, B.I.; Zolotar, B.; Weisman, J.

    1979-01-01

    An automated procedure determining a minimum cost refueling policy has been developed for light water reactors. The procedure is an extension of the equilibrium core approach previously devised for pressurized water reactors (PWRs). Use of 1 1/2-group theory has improved the accuracy of the nuclear model and eliminated tedious fitting of albedos. A simple heuristic algorithm for locating a good starting policy has materially reduced PWR computing time. Inclusion of void effects and use of the Haling principle for axial flux calculations extended the nuclear model to boiling water reactors (BWRs). A good initial estimate of the refueling policy is obtained by recognizing that a nearly uniform distribution of reactivity provides low-power peaking. The initial estimate is improved upon by interchanging groups of four assemblies and is subsequently refined by interchanging individual assemblies. The method yields very favorable results, is simpler than previously proposed BWR fuel optimization schemes, and retains power cost as the objective function

  5. Optimized design of micromachined electric field mills to maximize electrostatic field sensitivity

    Directory of Open Access Journals (Sweden)

    Yu Zhou

    2016-07-01

    Full Text Available This paper describes the design optimization of a micromachined electric field mill, in relation to maximizing its output signal. The cases studied are for a perforated electrically grounded shutter vibrating laterally over sensing electrodes. It is shown that when modeling the output signal of the sensor, the differential charge on the sense electrodes when exposed to vs. visibly shielded from the incident electric field must be considered. Parametric studies of device dimensions show that the shutter thickness and its spacing from the underlying electrodes should be minimized as these parameters very strongly affect the MEFM signal. Exploration of the shutter perforation size and sense electrode width indicate that the best MEFM design is one where shutter perforation widths are a few times larger than the sense electrode widths. Keywords: MEFM, Finite element method, Electric field measurement, MEMS, Micromachining

  6. Flow field optimization for proton exchange membrane fuel cells with varying channel heights and widths

    International Nuclear Information System (INIS)

    Wang Xiaodong; Huang Yuxian; Cheng, C.-H.; Jang, J.-Y.; Lee, D.-J.; Yan, W.-M.; Su Ay

    2009-01-01

    The optimal cathode flow field design of a single serpentine proton exchange membrane fuel cell is obtained by adopting a combined optimization procedure including a simplified conjugate-gradient method (SCGM) and a completely three-dimensional, two-phase, non-isothermal fuel cell model. The cell output power density P cell is the objective function to be maximized with channel heights, H 1 -H 5 , and channel widths, W 2 -W 5 as search variables. The optimal design has tapered channels 1, 3 and 4, and diverging channels 2 and 5, producing 22.51% increment compared with the basic design with all heights and widths setting as 1 mm. Reduced channel heights of channels 2-4 significantly enhance sub-rib convection to effectively transport oxygen to and liquid water out of diffusion layer. The final diverging channel prevents significant leakage of fuel to outlet via sub-rib convection from channel 4. Near-optimal design without huge loss in cell performance but is easily manufactured is discussed.

  7. Optimization of a Multi-Step Procedure for Isolation of Chicken Bone Collagen

    OpenAIRE

    Cansu, ?mran; Boran, G?khan

    2015-01-01

    Chicken bone is not adequately utilized despite its high nutritional value and protein content. Although not a common raw material, chicken bone can be used in many different ways besides manufacturing of collagen products. In this study, a multi-step procedure was optimized to isolate chicken bone collagen for higher yield and quality for manufacture of collagen products. The chemical composition of chicken bone was 2.9% nitrogen corresponding to about 15.6% protein, 9.5% fat, 14.7% mineral ...

  8. A derived heuristics based multi-objective optimization procedure for micro-grid scheduling

    Science.gov (United States)

    Li, Xin; Deb, Kalyanmoy; Fang, Yanjun

    2017-06-01

    With the availability of different types of power generators to be used in an electric micro-grid system, their operation scheduling as the load demand changes with time becomes an important task. Besides satisfying load balance constraints and the generator's rated power, several other practicalities, such as limited availability of grid power and restricted ramping of power output from generators, must all be considered during the operation scheduling process, which makes it difficult to decide whether the optimization results are accurate and satisfactory. In solving such complex practical problems, heuristics-based customized optimization algorithms are suggested. However, due to nonlinear and complex interactions of variables, it is difficult to come up with heuristics in such problems off-hand. In this article, a two-step strategy is proposed in which the first task deciphers important heuristics about the problem and the second task utilizes the derived heuristics to solve the original problem in a computationally fast manner. Specifically, the specific operation scheduling is considered from a two-objective (cost and emission) point of view. The first task develops basic and advanced level knowledge bases offline from a series of prior demand-wise optimization runs and then the second task utilizes them to modify optimized solutions in an application scenario. Results on island and grid connected modes and several pragmatic formulations of the micro-grid operation scheduling problem clearly indicate the merit of the proposed two-step procedure.

  9. VISUALIZATION SOFTWARE DEVELOPMENT FOR PROCEDURE OF MULTI-DIMENSIONAL OPTIMIZATION OF TECHNOLOGICAL PROCESS FUNCTIONAL PARAMETERS

    Directory of Open Access Journals (Sweden)

    E. N. Ishakova

    2016-05-01

    Full Text Available A method for multi-criteria optimization of the design parameters for technological object is described. The existing optimization methods are overviewed, and works in the field of basic research and applied problems are analyzed. The problem is formulated, based on the process requirements, making it possible to choose the geometrical dimensions of machine tips and the flow rate of the process, so that the resulting technical and economical parameters were optimal. In the problem formulation application of the performance method adapted to a particular domain is described. Task implementation is shown; the method of characteristics creation for the studied object in view of some restrictions for parameters in both analytical and graphical representation. On the basis of theoretical research the software system is developed that gives the possibility to automate the discovery of optimal solutions for specific problems. Using available information sources, that characterize the object of study, it is possible to establish identifiers, add restrictions from the one side, and in the interval as well. Obtained result is a visual depiction of dependence of the main study parameters on the others, which may have an impact on both the flow of the process, and the quality of products. The resulting optimal area shows the use of different design options for technological object in an acceptable kinematic range that makes it possible for the researcher to choose the best design solution.

  10. Field emission from optimized structure of carbon nanotube field emitter array

    International Nuclear Information System (INIS)

    Chouhan, V.; Noguchi, T.; Kato, S.

    2016-01-01

    The authors report a detail study on the emission properties of field emitter array (FEA) of micro-circular emitters of multiwall carbon nanotubes (CNTs). The FEAs were fabricated on patterned substrates prepared with an array of circular titanium (Ti) islands on titanium nitride coated tantalum substrates. CNTs were rooted into these Ti islands to prepare an array of circular emitters. The circular emitters were prepared in different diameters and pitches in order to optimize their structure for acquiring a high emission current. The pitch was varied from 0 to 600 μm, while a diameter of circular emitters was kept constant to be 50 μm in order to optimize a pitch. For diameter optimization, a diameter was changed from 50 to 200 μm while keeping a constant edge-to-edge distance of 150 μm between the circular emitters. The FEA with a diameter of 50 μm and a pitch of 120 μm was found to be the best to achieve an emission current of 47 mA corresponding to an effective current density of 30.5 A/cm"2 at 7 V/μm. The excellent emission current was attributed to good quality of CNT rooting into the substrate and optimized FEA structure, which provided a high electric field on a whole circular emitter of 50 μm and the best combination of the strong edge effect and CNT coverage. The experimental results were confirmed with computer simulation.

  11. Field emission from optimized structure of carbon nanotube field emitter array

    Energy Technology Data Exchange (ETDEWEB)

    Chouhan, V., E-mail: vchouhan@post.kek.jp, E-mail: vijaychouhan84@gmail.com [School of High Energy Accelerator, The Graduate University for Advanced Studies, Tsukuba 305-0801 (Japan); Noguchi, T. [High Energy Accelerator Research Organization (KEK), Tsukuba 305-0801 (Japan); Kato, S. [School of High Energy Accelerator, The Graduate University for Advanced Studies, Tsukuba 305-0801 (Japan); High Energy Accelerator Research Organization (KEK), Tsukuba 305-0801 (Japan)

    2016-04-07

    The authors report a detail study on the emission properties of field emitter array (FEA) of micro-circular emitters of multiwall carbon nanotubes (CNTs). The FEAs were fabricated on patterned substrates prepared with an array of circular titanium (Ti) islands on titanium nitride coated tantalum substrates. CNTs were rooted into these Ti islands to prepare an array of circular emitters. The circular emitters were prepared in different diameters and pitches in order to optimize their structure for acquiring a high emission current. The pitch was varied from 0 to 600 μm, while a diameter of circular emitters was kept constant to be 50 μm in order to optimize a pitch. For diameter optimization, a diameter was changed from 50 to 200 μm while keeping a constant edge-to-edge distance of 150 μm between the circular emitters. The FEA with a diameter of 50 μm and a pitch of 120 μm was found to be the best to achieve an emission current of 47 mA corresponding to an effective current density of 30.5 A/cm{sup 2} at 7 V/μm. The excellent emission current was attributed to good quality of CNT rooting into the substrate and optimized FEA structure, which provided a high electric field on a whole circular emitter of 50 μm and the best combination of the strong edge effect and CNT coverage. The experimental results were confirmed with computer simulation.

  12. Optimization of procedures for mercury-203 instrumental neutron activation analysis in human urine

    Energy Technology Data Exchange (ETDEWEB)

    Blotcky, A J; Claassen, J P [Nebraska Univ., Omaha, NE (United States). Medical Center; Fung, Y K [Nebraska Univ., Lincoln, NE (United States). Dept. of Chemistry; Meade, A G; Rack, E P [Nebraska Univ., Lincoln, NE (United States)

    1995-08-01

    Mercury, a known neurotoxin, has been implicated in etiology and pathogenesis of such disease states as Alzheimer`s and Parkinson`s diseases. There is concern that the exposure to mercury vapor released from dental amalgam restorations is a potential health hazard. Measurement of mercury concentrations in blood or urine may be useful in diagnosis of mercury poisoning and in assessing the extent exposure. This study describes the optimization of pre-neutron activation analysis procedures such as sampling, selection of irradiation and counting vials and acid digestion in order to minimize mercury loss via volatilization and/or permeation through containers. Therefore, the determination of mercury can be complicated by these potential losses. In the optimized procedure 20mL of urine was spiked with three different concentrations of mercury, digested with concentrated nitric acid, and placed in polypropylene vials for irradiation and counting. Analysis was performed by subtracting the Se-75 photopeak contribution to the 279 keV Hg-203 photopeak and applying the method of standard additions. Urinary mercury concentrations in normal human subjects were determined to be of the order of 10ng/mL. (author). 22 refs., 1 fig., 5 tabs.

  13. A pilot study of short-duration sputum pretreatment procedures for optimizing smear microscopy for tuberculosis.

    Directory of Open Access Journals (Sweden)

    Peter Daley

    2009-05-01

    Full Text Available Direct sputum smear microscopy for tuberculosis (TB lacks sensitivity for the detection of acid fast bacilli. Sputum pretreatment procedures may enhance sensitivity. We did a pilot study to compare the diagnostic accuracy and incremental yield of two short-duration (<1 hour sputum pretreatment procedures to optimize direct smears among patients with suspected TB at a referral hospital in India.Blinded laboratory comparison of bleach and universal sediment processing (USP pretreated centrifuged auramine smears to direct Ziehl-Neelsen (ZN and direct auramine smears and to solid (Loweinstein-Jensen (LJ and liquid (BACTEC 460 culture. 178 pulmonary and extrapulmonary TB suspects were prospectively recruited during a one year period. Thirty six (20.2% were positive by either solid or liquid culture. Direct ZN smear detected 22 of 36 cases and direct auramine smears detected 26 of 36 cases. Bleach and USP centrifugation detected 24 cases each, providing no incremental yield beyond direct smears. When compared to combined culture, pretreated smears were not more sensitive than direct smears (66.6% vs 61.1 (ZN or 72.2 (auramine, and were not more specific (92.3% vs 93.0 (ZN or 97.2 (auramine.Short duration sputum pretreatment with bleach and USP centrifugation did not increase yield as compared to direct sputum smears. Further work is needed to confirm this in a larger study and also determine if longer duration pre-treatment might be effective in optimizing smear microscopy for TB.

  14. Optimization of procedures for mercury-203 instrumental neutron activation analysis in human urine

    International Nuclear Information System (INIS)

    Blotcky, A.J.; Claassen, J.P.

    1995-01-01

    Mercury, a known neurotoxin, has been implicated in etiology and pathogenesis of such disease states as Alzheimer's and Parkinson's diseases. There is concern that the exposure to mercury vapor released from dental amalgam restorations is a potential health hazard. Measurement of mercury concentrations in blood or urine may be useful in diagnosis of mercury poisoning and in assessing the extent exposure. This study describes the optimization of pre-neutron activation analysis procedures such as sampling, selection of irradiation and counting vials and acid digestion in order to minimize mercury loss via volatilization and/or permeation through containers. Therefore, the determination of mercury can be complicated by these potential losses. In the optimized procedure 20mL of urine was spiked with three different concentrations of mercury, digested with concentrated nitric acid, and placed in polypropylene vials for irradiation and counting. Analysis was performed by subtracting the Se-75 photopeak contribution to the 279 keV Hg-203 photopeak and applying the method of standard additions. Urinary mercury concentrations in normal human subjects were determined to be of the order of 10ng/mL. (author). 22 refs., 1 fig., 5 tabs

  15. Optimal information transfer in enzymatic networks: A field theoretic formulation

    Science.gov (United States)

    Samanta, Himadri S.; Hinczewski, Michael; Thirumalai, D.

    2017-07-01

    Signaling in enzymatic networks is typically triggered by environmental fluctuations, resulting in a series of stochastic chemical reactions, leading to corruption of the signal by noise. For example, information flow is initiated by binding of extracellular ligands to receptors, which is transmitted through a cascade involving kinase-phosphatase stochastic chemical reactions. For a class of such networks, we develop a general field-theoretic approach to calculate the error in signal transmission as a function of an appropriate control variable. Application of the theory to a simple push-pull network, a module in the kinase-phosphatase cascade, recovers the exact results for error in signal transmission previously obtained using umbral calculus [Hinczewski and Thirumalai, Phys. Rev. X 4, 041017 (2014), 10.1103/PhysRevX.4.041017]. We illustrate the generality of the theory by studying the minimal errors in noise reduction in a reaction cascade with two connected push-pull modules. Such a cascade behaves as an effective three-species network with a pseudointermediate. In this case, optimal information transfer, resulting in the smallest square of the error between the input and output, occurs with a time delay, which is given by the inverse of the decay rate of the pseudointermediate. Surprisingly, in these examples the minimum error computed using simulations that take nonlinearities and discrete nature of molecules into account coincides with the predictions of a linear theory. In contrast, there are substantial deviations between simulations and predictions of the linear theory in error in signal propagation in an enzymatic push-pull network for a certain range of parameters. Inclusion of second-order perturbative corrections shows that differences between simulations and theoretical predictions are minimized. Our study establishes that a field theoretic formulation of stochastic biological signaling offers a systematic way to understand error propagation in

  16. Simulation and Optimization of Silicon Solar Cell Back Surface Field

    Directory of Open Access Journals (Sweden)

    Souad TOBBECHE

    2015-11-01

    Full Text Available In this paper, TCAD Silvaco (Technology Computer Aided Design software has been used to study the Back Surface Field (BSF effect of a p+ silicon layer for a n+pp+ silicon solar cell. To study this effect, the J-V characteristics and the external quantum efficiency (EQE are simulated under AM 1.5 illumination for two types of cells. The first solar cell is without BSF (n+p structure while the second one is with BSF (n+pp+ structure. The creation of the BSF on the rear face of the cell results in efficiency h of up to 16.06% with a short-circuit current density Jsc = 30.54 mA/cm2, an open-circuit voltage Voc = 0.631 V, a fill factor FF = 0.832 and a clear improvement of the spectral response obtained in the long wavelengths range. An electric field and a barrier of potential are created by the BSF and located at the junction p+/p with a maximum of 5800 V/cm and 0.15 V, respectively. The optimization of the BSF layer shows that the cell performance improves with the p+ thickness between 0.35 – 0.39 µm, the p+ doping dose is about 2 × 1014 cm-2, the maximum efficiency up to 16.19 %. The cell efficiency is more sensitive to the value of the back surface recombination velocity above a value of 103 cm/s in n+p than n+pp+ solar cell.DOI: http://dx.doi.org/10.5755/j01.ms.21.4.9565

  17. Optimized molten salt receivers for ultimate trough solar fields

    Science.gov (United States)

    Riffelmann, Klaus-J.; Richert, Timo; Kuckelkorn, Thomas

    2016-05-01

    Today parabolic trough collectors are the most successful concentrating solar power (CSP) technology. For the next development step new systems with increased operation temperature and new heat transfer fluids (HTF) are currently developed. Although the first power tower projects have successfully been realized, up to now there is no evidence of an all-dominant economic or technical advantage of power tower or parabolic trough. The development of parabolic trough technology towards higher performance and significant cost reduction have led to significant improvements in competitiveness. The use of molten salt instead of synthetic oil as heat transfer fluid will bring down the levelized costs of electricity (LCOE) even further while providing dispatchable energy with high capacity factors. FLABEG has developed the Ultimate TroughTM (UT) collector, jointly with sbp Sonne GmbH and supported by public funds. Due to its validated high optical accuracy, the collector is very suitable to operate efficiently at elevated temperatures up to 550 °C. SCHOTT will drive the key-innovations by introducing the 4th generation solar receiver that addresses the most significant performance and cost improvement measures. The new receivers have been completely redesigned to provide a product platform that is ready for high temperature operation up to 550 °C. Moreover distinct product features have been introduced to reduce costs and risks in solar field assembly and installation. The increased material and design challenges incurred with the high temperature operation have been reflected in sophisticated qualification and validation procedures.

  18. Optimizing fracture and completion design in the Westerose field

    Energy Technology Data Exchange (ETDEWEB)

    Dunn-Norman, S. [Missouri Univ., Rolla, MO (United States); Griffiths, E.; Barnhart, W. [Pan-Canadian Petroleum Ltd., Calgary, AB (Canada); Aunger, D.; Kenny, L.; Halvaci, M.

    1998-12-31

    An experimental study was conducted to determine the feasibility of developing additional gas reserves in the tight sands located between the main bar trends in the Westerose gas field, located 75 km south of Edmonton, Alberta. As part of the study, fracturing and completion alternatives in the Glauconitic `bar` and `interbar` sands were analyzed and compared. Optimal fracture designs for vertical wells were determined for each type of sand. Vertical well performance was compared to stimulated and unstimulated horizontal wells drilled either parallel or perpendicular to the minimum in-situ stress. Results indicated that in-situ permeabilities in the interbar sands were lower than anticipated. It was also shown that over the permeability ranges studied, predicted rates matched actual rates for both vertical fractured and multifractured horizontal wells, suggesting that analytical models can be used to assess anticipated well performance. A further conclusion drawn from the study was that by stimulating a wide variety of permeability ranges, well orientations, anisotropy, fracture orientations and completion options can be determined. 12 refs., 7 tabs., 4 figs.

  19. Determination of optimal ultrasound planes for the initialisation of image registration during endoscopic ultrasound-guided procedures.

    Science.gov (United States)

    Bonmati, Ester; Hu, Yipeng; Gibson, Eli; Uribarri, Laura; Keane, Geri; Gurusami, Kurinchi; Davidson, Brian; Pereira, Stephen P; Clarkson, Matthew J; Barratt, Dean C

    2018-06-01

    Navigation of endoscopic ultrasound (EUS)-guided procedures of the upper gastrointestinal (GI) system can be technically challenging due to the small fields-of-view of ultrasound and optical devices, as well as the anatomical variability and limited number of orienting landmarks during navigation. Co-registration of an EUS device and a pre-procedure 3D image can enhance the ability to navigate. However, the fidelity of this contextual information depends on the accuracy of registration. The purpose of this study was to develop and test the feasibility of a simulation-based planning method for pre-selecting patient-specific EUS-visible anatomical landmark locations to maximise the accuracy and robustness of a feature-based multimodality registration method. A registration approach was adopted in which landmarks are registered to anatomical structures segmented from the pre-procedure volume. The predicted target registration errors (TREs) of EUS-CT registration were estimated using simulated visible anatomical landmarks and a Monte Carlo simulation of landmark localisation error. The optimal planes were selected based on the 90th percentile of TREs, which provide a robust and more accurate EUS-CT registration initialisation. The method was evaluated by comparing the accuracy and robustness of registrations initialised using optimised planes versus non-optimised planes using manually segmented CT images and simulated ([Formula: see text]) or retrospective clinical ([Formula: see text]) EUS landmarks. The results show a lower 90th percentile TRE when registration is initialised using the optimised planes compared with a non-optimised initialisation approach (p value [Formula: see text]). The proposed simulation-based method to find optimised EUS planes and landmarks for EUS-guided procedures may have the potential to improve registration accuracy. Further work will investigate applying the technique in a clinical setting.

  20. Multi-objective Optimization of Departure Procedures at Gimpo International Airport

    Science.gov (United States)

    Kim, Junghyun; Lim, Dongwook; Monteiro, Dylan Jonathan; Kirby, Michelle; Mavris, Dimitri

    2018-04-01

    Most aviation communities have increasing concerns about the environmental impacts, which are directly linked to health issues for local residents near the airport. In this study, the environmental impact of different departure procedures using the Aviation Environmental Design Tool (AEDT) was analyzed. First, actual operational data were compiled at Gimpo International Airport (March 20, 2017) from an open source. Two modifications were made in the AEDT to model the operational circumstances better and the preliminary AEDT simulations were performed according to the acquired operational procedures. Simulated noise results showed good agreements with noise measurement data at specific locations. Second, a multi-objective optimization of departure procedures was performed for the Boeing 737-800. Four design variables were selected and AEDT was linked to a variety of advanced design methods. The results showed that takeoff thrust had the greatest influence and it was found that fuel burn and noise had an inverse relationship. Two points representing each fuel burn and noise optimum on the Pareto front were parsed and run in AEDT to compare with the baseline. The results showed that the noise optimum case reduced Sound Exposure Level 80-dB noise exposure area by approximately 5% while the fuel burn optimum case reduced total fuel burn by 1% relative to the baseline for aircraft-level analysis.

  1. Fringing field optimization of hemispherical deflector analyzers using BEM and FDM

    Energy Technology Data Exchange (ETDEWEB)

    Sise, Omer, E-mail: omersise@aku.edu.t [Department of Physics, Science and Arts Faculty, Afyon Kocatepe University, 03200 Afyonkarahisar (Turkey); Ulu, Melike; Dogan, Mevlut [Department of Physics, Science and Arts Faculty, Afyon Kocatepe University, 03200 Afyonkarahisar (Turkey); Martinez, Genoveva [Department Fisica Aplicada III, Fac. de Fisica, UCM 28040-Madrid (Spain); Zouros, Theo J.M. [Department of Physics, University of Crete, P.O. Box 2208, 71003 Heraklion, Crete (Greece); TANDEM Accelerator Laboratory, Institute of Nuclear Physics, NCSR ' Demokritos' , 153.10 Aghia Paraskevi, Athens (Greece)

    2010-02-15

    In this paper we present numerical modeling results for fringing field optimization of hemispherical deflector analyzers (HDAs), simulated using boundary-element and finite-difference numerical methods. Optimization of the fringing field aberrations of HDAs is performed by using a biased optical axis and an optimized entry position offset (paracentric) from the center position used in conventional HDAs. The described optimization achieves first-order focusing thus also further improving the energy resolution of HDAs.

  2. Optimal estimation of spatially variable recharge and transmissivity fields under steady-state groundwater flow. Part 1. Theory

    Science.gov (United States)

    Graham, Wendy D.; Tankersley, Claude D.

    1994-05-01

    Stochastic methods are used to analyze two-dimensional steady groundwater flow subject to spatially variable recharge and transmissivity. Approximate partial differential equations are developed for the covariances and cross-covariances between the random head, transmissivity and recharge fields. Closed-form solutions of these equations are obtained using Fourier transform techniques. The resulting covariances and cross-covariances can be incorporated into a Bayesian conditioning procedure which provides optimal estimates of the recharge, transmissivity and head fields given available measurements of any or all of these random fields. Results show that head measurements contain valuable information for estimating the random recharge field. However, when recharge is treated as a spatially variable random field, the value of head measurements for estimating the transmissivity field can be reduced considerably. In a companion paper, the method is applied to a case study of the Upper Floridan Aquifer in NE Florida.

  3. Optimization of wet digestion procedure of blood and tissue for selenium determination by means of 75Se tracer

    International Nuclear Information System (INIS)

    Holynska, B.; Lipinska-Kalita, K.

    1977-01-01

    Selenium-75 tracer has been used for optimization of analytical procedure of selenium determination in blood and tissue. Wet digestion procedure and reduction of selenium to its elemental form with tellurium as coprecipitant have been tested. It is seen that the use of a mixture of perchloric and sulphuric acid with sodium molybdenate for the wet digestion of organic matter followed by the reduction of selenium to its elementary form by a mixture of stannous chloride and hydroxylamine hydrochloride results in very good recovery of selenium. Recovery of selenium obtained with the use of optimized analytical procedure amounts to 95% and precision is equal to 4.2%. (T.I.)

  4. Constrained optimization for position calibration of an NMR field camera.

    Science.gov (United States)

    Chang, Paul; Nassirpour, Sahar; Eschelbach, Martin; Scheffler, Klaus; Henning, Anke

    2018-07-01

    Knowledge of the positions of field probes in an NMR field camera is necessary for monitoring the B 0 field. The typical method of estimating these positions is by switching the gradients with known strengths and calculating the positions using the phases of the FIDs. We investigated improving the accuracy of estimating the probe positions and analyzed the effect of inaccurate estimations on field monitoring. The field probe positions were estimated by 1) assuming ideal gradient fields, 2) using measured gradient fields (including nonlinearities), and 3) using measured gradient fields with relative position constraints. The fields measured with the NMR field camera were compared to fields acquired using a dual-echo gradient recalled echo B 0 mapping sequence. Comparisons were done for shim fields from second- to fourth-order shim terms. The position estimation was the most accurate when relative position constraints were used in conjunction with measured (nonlinear) gradient fields. The effect of more accurate position estimates was seen when compared to fields measured using a B 0 mapping sequence (up to 10%-15% more accurate for some shim fields). The models acquired from the field camera are sensitive to noise due to the low number of spatial sample points. Position estimation of field probes in an NMR camera can be improved using relative position constraints and nonlinear gradient fields. Magn Reson Med 80:380-390, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  5. An optimized target-field method for MRI transverse biplanar gradient coil design

    International Nuclear Information System (INIS)

    Zhang, Rui; Xu, Jing; Huang, Kefu; Zhang, Jue; Fang, Jing; Fu, Youyi; Li, Yangjing

    2011-01-01

    Gradient coils are essential components of magnetic resonance imaging (MRI) systems. In this paper, we present an optimized target-field method for designing a transverse biplanar gradient coil with high linearity, low inductance and small resistance, which can well satisfy the requirements of permanent-magnet MRI systems. In this new method, the current density is expressed by trigonometric basis functions with unknown coefficients in polar coordinates. Following the standard procedures, we construct an objective function with respect to the total square errors of the magnetic field at all target-field points with the penalty items associated with the stored magnetic energy and the dissipated power. By adjusting the two penalty factors and minimizing the objective function, the appropriate coefficients of the current density are determined. Applying the stream function method to the current density, the specific winding patterns on the planes can be obtained. A novel biplanar gradient coil has been designed using this method to operate in a permanent-magnet MRI system. In order to verify the validity of the proposed approach, the gradient magnetic field generated by the resulted current density has been calculated via the Biot–Savart law. The results have demonstrated the effectiveness and advantage of this proposed method

  6. A practical optimization procedure for radial BWR fuel lattice design using tabu search with a multiobjective function

    International Nuclear Information System (INIS)

    Francois, J.L.; Martin-del-Campo, C.; Francois, R.; Morales, L.B.

    2003-01-01

    An optimization procedure based on the tabu search (TS) method was developed for the design of radial enrichment and gadolinia distributions for boiling water reactor (BWR) fuel lattices. The procedure was coded in a computing system in which the optimization code uses the tabu search method to select potential solutions and the HELIOS code to evaluate them. The goal of the procedure is to search for an optimal fuel utilization, looking for a lattice with minimum average enrichment, with minimum deviation of reactivity targets and with a local power peaking factor (PPF) lower than a limit value. Time-dependent-depletion (TDD) effects were considered in the optimization process. The additive utility function method was used to convert the multiobjective optimization problem into a single objective problem. A strategy to reduce the computing time employed by the optimization was developed and is explained in this paper. An example is presented for a 10x10 fuel lattice with 10 different fuel compositions. The main contribution of this study is the development of a practical TDD optimization procedure for BWR fuel lattice design, using TS with a multiobjective function, and a strategy to economize computing time

  7. Bifurcations of optimal vector fields in the shallow lake model

    NARCIS (Netherlands)

    Kiseleva, T.; Wagener, F.O.O.

    2010-01-01

    The solution structure of the set of optimal solutions of the shallow lake problem, a problem of optimal pollution management, is studied as we vary the values of the system parameters: the natural resilience, the relative importance of the resource for social welfare and the future discount rate.

  8. Bifurcations of optimal vector fields in the shallow lake model

    NARCIS (Netherlands)

    Kiseleva, T.; Wagener, F.

    2009-01-01

    The solution structure of the set of optimal solutions of the shallow lake problem, a problem of optimal pollution management, is studied as we vary the values of the system parameters: the natural resilience, the relative importance of the resource for social welfare and the future discount rate.

  9. Evaluation and optimization of DNA extraction and purification procedures for soil and sediment samples.

    Science.gov (United States)

    Miller, D N; Bryant, J E; Madsen, E L; Ghiorse, W C

    1999-11-01

    We compared and statistically evaluated the effectiveness of nine DNA extraction procedures by using frozen and dried samples of two silt loam soils and a silt loam wetland sediment with different organic matter contents. The effects of different chemical extractants (sodium dodecyl sulfate [SDS], chloroform, phenol, Chelex 100, and guanadinium isothiocyanate), different physical disruption methods (bead mill homogenization and freeze-thaw lysis), and lysozyme digestion were evaluated based on the yield and molecular size of the recovered DNA. Pairwise comparisons of the nine extraction procedures revealed that bead mill homogenization with SDS combined with either chloroform or phenol optimized both the amount of DNA extracted and the molecular size of the DNA (maximum size, 16 to 20 kb). Neither lysozyme digestion before SDS treatment nor guanidine isothiocyanate treatment nor addition of Chelex 100 resin improved the DNA yields. Bead mill homogenization in a lysis mixture containing chloroform, SDS, NaCl, and phosphate-Tris buffer (pH 8) was found to be the best physical lysis technique when DNA yield and cell lysis efficiency were used as criteria. The bead mill homogenization conditions were also optimized for speed and duration with two different homogenizers. Recovery of high-molecular-weight DNA was greatest when we used lower speeds and shorter times (30 to 120 s). We evaluated four different DNA purification methods (silica-based DNA binding, agarose gel electrophoresis, ammonium acetate precipitation, and Sephadex G-200 gel filtration) for DNA recovery and removal of PCR inhibitors from crude extracts. Sephadex G-200 spin column purification was found to be the best method for removing PCR-inhibiting substances while minimizing DNA loss during purification. Our results indicate that for these types of samples, optimum DNA recovery requires brief, low-speed bead mill homogenization in the presence of a phosphate-buffered SDS-chloroform mixture, followed

  10. Evaluation and optimization of the man-machine interface in nuclear power plants using the HEROS procedure in PSA

    International Nuclear Information System (INIS)

    Richei, A.; Koch, M.K.; Unger, H.; Hauptmanns, U.

    1998-01-01

    For the probabilistic evaluation and optimization of the man-machine-system a new procedure is developed. This and the resulting expert system, which is based on the fuzzy set theory, is called HEROS, an acronym for Human Error Rate Assessment and Optimizing System. There are several existing procedures for the probabilistic evaluation of human errors, which have several disadvantages. However, in all of these procedures fuzzy verbal expressions are often used for the evaluation of human factors, also in the best known procedures. This use of verbal expressions for describing performance-shaping factors, enabling the evaluation of human factors is the basic approach for HEROS. A model of a modem man-machine-system is the basis of the procedure. Results from ergonomic studies are used to establish a rule-based expert system. HEROS simplifies the importance analysis for the evaluation of human factors, which is necessary for the optimization of the man-machine-system. It can be used in all areas of probabilistic safety assessment. The application of HEROS in the scope of accident management procedures and the comparison with the results of other procedures as an example for the usefulness and substantially more extensive applicability of this new procedure will be shown. (author)

  11. Technical procedures for implementation of background environmental radioactivity site studies, Deaf Smith County site, Texas: Environmental Field Program: Preliminary draft

    International Nuclear Information System (INIS)

    1987-09-01

    The purpose of this technical procedure is to describe the method for performing field maintenance on low-volume air samplers and the associated topics of personnel and organization, procedure preparation, documentation, and quality assurance. The scope of this procedure includes the maintenance of low-volume air samplers in the field and does not encompass maintenance performed by the manufacturer

  12. Core design optimization by integration of a fast 3-D nodal code in a heuristic search procedure

    Energy Technology Data Exchange (ETDEWEB)

    Geemert, R. van; Leege, P.F.A. de; Hoogenboom, J.E.; Quist, A.J. [Delft University of Technology, NL-2629 JB Delft (Netherlands)

    1998-07-01

    An automated design tool is being developed for the Hoger Onderwijs Reactor (HOR) in Delft, the Netherlands, which is a 2 MWth swimming-pool type research reactor. As a black box evaluator, the 3-D nodal code SILWER, which up to now has been used only for evaluation of predetermined core designs, is integrated in the core optimization procedure. SILWER is a part of PSl's ELCOS package and features optional additional thermal-hydraulic, control rods and xenon poisoning calculations. This allows for fast and accurate evaluation of different core designs during the optimization search. Special attention is paid to handling the in- and output files for SILWER such that no adjustment of the code itself is required for its integration in the optimization programme. The optimization objective, the safety and operation constraints, as well as the optimization procedure, are discussed. (author)

  13. Core design optimization by integration of a fast 3-D nodal code in a heuristic search procedure

    International Nuclear Information System (INIS)

    Geemert, R. van; Leege, P.F.A. de; Hoogenboom, J.E.; Quist, A.J.

    1998-01-01

    An automated design tool is being developed for the Hoger Onderwijs Reactor (HOR) in Delft, the Netherlands, which is a 2 MWth swimming-pool type research reactor. As a black box evaluator, the 3-D nodal code SILWER, which up to now has been used only for evaluation of predetermined core designs, is integrated in the core optimization procedure. SILWER is a part of PSl's ELCOS package and features optional additional thermal-hydraulic, control rods and xenon poisoning calculations. This allows for fast and accurate evaluation of different core designs during the optimization search. Special attention is paid to handling the in- and output files for SILWER such that no adjustment of the code itself is required for its integration in the optimization programme. The optimization objective, the safety and operation constraints, as well as the optimization procedure, are discussed. (author)

  14. Application of an optimized AM procedure following a SBO in a VVER1000

    International Nuclear Information System (INIS)

    Cherubini, Marco; D'Auria, Francesco; Petrangeli, Gianni; Muellner, Nikolaus

    2006-01-01

    The University of Pisa was involved in investigations of an Accident Management procedure based on passive feed water injection. Some experiments were performed to validate this possibility (e.g. in LOBI and Bethsy facilities) and fully analyzed by thermal hydraulic system codes. Recent activities in which the University of Pisa is engaged (also as leader) are focused on VVER-1000 safety analyses. The idea is now to use the acquired knowledge to explore if a procedure based on passive feed water injection is applicable and can provide any benefits to the Russian design pressurized plant. The postulated accident is a station blackout, in such a way only passive systems are available. The proposed AM is based on secondary and primary side depressurisation in sequence. The secondary side depressurisation performed by the BRU-A valves has the scope to feed passively the SGs with the water left in the feed water lines and in the deaerators. The primary side depressurisation, via the PORV, is foreseen to keep the plant at the lowest pressure (to reduce the energy of the system) and to maximize the 'grace time' of the plant. Three cases are here considered: no operator action, application of the optimized AM sequence, application of the AM procedure at the last time when it is effective. The intention of this paper is to show that in case of an unlikely event such a SBO the implementation of a strategy based on systems not designed for specific safety application can have a large impact on the 'grace time' of the plant. (author)

  15. Field Operations and Enforcement Manual for Air Pollution Control. Volume III: Inspection Procedures for Specific Industries.

    Science.gov (United States)

    Weisburd, Melvin I.

    The Field Operations and Enforcement Manual for Air Pollution Control, Volume III, explains in detail the following: inspection procedures for specific sources, kraft pulp mills, animal rendering, steel mill furnaces, coking operations, petroleum refineries, chemical plants, non-ferrous smelting and refining, foundries, cement plants, aluminum…

  16. Well Field Management Using Multi-Objective Optimization

    DEFF Research Database (Denmark)

    Hansen, Annette Kirstine; Hendricks Franssen, H. J.; Bauer-Gottwein, Peter

    2013-01-01

    with infiltration basins, injection wells and abstraction wells. The two management objectives are to minimize the amount of water needed for infiltration and to minimize the risk of getting contaminated water into the drinking water wells. The management is subject to a daily demand fulfilment constraint. Two...... different optimization methods are tested. Constant scheduling where decision variables are held constant during the time of optimization, and sequential scheduling where the optimization is performed stepwise for daily time steps. The latter is developed to work in a real-time situation. Case study...

  17. Optimization of exposure parameters in full field digital mammography

    International Nuclear Information System (INIS)

    Williams, Mark B.; Raghunathan, Priya; More, Mitali J.; Seibert, J. Anthony; Kwan, Alexander; Lo, Joseph Y.; Samei, Ehsan; Ranger, Nicole T.; Fajardo, Laurie L.; McGruder, Allen; McGruder, Sandra M.; Maidment, Andrew D. A.; Yaffe, Martin J.; Bloomquist, Aili; Mawdsley, Gordon E.

    2008-01-01

    Optimization of exposure parameters (target, filter, and kVp) in digital mammography necessitates maximization of the image signal-to-noise ratio (SNR), while simultaneously minimizing patient dose. The goal of this study is to compare, for each of the major commercially available full field digital mammography (FFDM) systems, the impact of the selection of technique factors on image SNR and radiation dose for a range of breast thickness and tissue types. This phantom study is an update of a previous investigation and includes measurements on recent versions of two of the FFDM systems discussed in that article, as well as on three FFDM systems not available at that time. The five commercial FFDM systems tested, the Senographe 2000D from GE Healthcare, the Mammomat Novation DR from Siemens, the Selenia from Hologic, the Fischer Senoscan, and Fuji's 5000MA used with a Lorad M-IV mammography unit, are located at five different university test sites. Performance was assessed using all available x-ray target and filter combinations and nine different phantom types (three compressed thicknesses and three tissue composition types). Each phantom type was also imaged using the automatic exposure control (AEC) of each system to identify the exposure parameters used under automated image acquisition. The figure of merit (FOM) used to compare technique factors is the ratio of the square of the image SNR to the mean glandular dose. The results show that, for a given target/filter combination, in general FOM is a slowly changing function of kVp, with stronger dependence on the choice of target/filter combination. In all cases the FOM was a decreasing function of kVp at the top of the available range of kVp settings, indicating that higher tube voltages would produce no further performance improvement. For a given phantom type, the exposure parameter set resulting in the highest FOM value was system specific, depending on both the set of available target/filter combinations, and

  18. Computer-Based Procedures for Field Workers in Nuclear Power Plants: Development of a Model of Procedure Usage and Identification of Requirements

    Energy Technology Data Exchange (ETDEWEB)

    Katya Le Blanc; Johanna Oxstrand

    2012-04-01

    The nuclear industry is constantly trying to find ways to decrease the human error rate, especially the human errors associated with procedure use. As a step toward the goal of improving procedure use performance, researchers, together with the nuclear industry, have been looking at replacing the current paper-based procedures with computer-based procedure systems. The concept of computer-based procedures is not new by any means; however most research has focused on procedures used in the main control room. Procedures reviewed in these efforts are mainly emergency operating procedures and normal operating procedures. Based on lessons learned for these previous efforts we are now exploring a more unknown application for computer based procedures - field procedures, i.e. procedures used by nuclear equipment operators and maintenance technicians. The Idaho National Laboratory and participants from the U.S. commercial nuclear industry are collaborating in an applied research effort with the objective of developing requirements and specifications for a computer-based procedure system to be used by field workers. The goal is to identify the types of human errors that can be mitigated by using computer-based procedures and how to best design the computer-based procedures to do so. This paper describes the development of a Model of Procedure Use and the qualitative study on which the model is based. The study was conducted in collaboration with four nuclear utilities and five research institutes. During the qualitative study and the model development requirements and for computer-based procedures were identified.

  19. Creating optimized machine working patterns on agricultural fields

    OpenAIRE

    Mark Spekken

    2015-01-01

    In the current agricultural context, agricultural machine unproductivity on fields and their impacts on soil along pathways are unavoidable. These machines have direct and indirect costs associated to their work in field, with non-productive time spent in manoeuvres when these are reaching field borders; likewise, there is a double application of product when machines are covering headlands while adding farm inputs. Both issues aggravate under irregular field geometry. Moreover, unproductive ...

  20. Robust electromagnetically guided endoscopic procedure using enhanced particle swarm optimization for multimodal information fusion

    International Nuclear Information System (INIS)

    Luo, Xiongbiao; Wan, Ying; He, Xiangjian

    2015-01-01

    Purpose: Electromagnetically guided endoscopic procedure, which aims at accurately and robustly localizing the endoscope, involves multimodal sensory information during interventions. However, it still remains challenging in how to integrate these information for precise and stable endoscopic guidance. To tackle such a challenge, this paper proposes a new framework on the basis of an enhanced particle swarm optimization method to effectively fuse these information for accurate and continuous endoscope localization. Methods: The authors use the particle swarm optimization method, which is one of stochastic evolutionary computation algorithms, to effectively fuse the multimodal information including preoperative information (i.e., computed tomography images) as a frame of reference, endoscopic camera videos, and positional sensor measurements (i.e., electromagnetic sensor outputs). Since the evolutionary computation method usually limits its possible premature convergence and evolutionary factors, the authors introduce the current (endoscopic camera and electromagnetic sensor’s) observation to boost the particle swarm optimization and also adaptively update evolutionary parameters in accordance with spatial constraints and the current observation, resulting in advantageous performance in the enhanced algorithm. Results: The experimental results demonstrate that the authors’ proposed method provides a more accurate and robust endoscopic guidance framework than state-of-the-art methods. The average guidance accuracy of the authors’ framework was about 3.0 mm and 5.6° while the previous methods show at least 3.9 mm and 7.0°. The average position and orientation smoothness of their method was 1.0 mm and 1.6°, which is significantly better than the other methods at least with (2.0 mm and 2.6°). Additionally, the average visual quality of the endoscopic guidance was improved to 0.29. Conclusions: A robust electromagnetically guided endoscopy framework was

  1. Robust electromagnetically guided endoscopic procedure using enhanced particle swarm optimization for multimodal information fusion.

    Science.gov (United States)

    Luo, Xiongbiao; Wan, Ying; He, Xiangjian

    2015-04-01

    Electromagnetically guided endoscopic procedure, which aims at accurately and robustly localizing the endoscope, involves multimodal sensory information during interventions. However, it still remains challenging in how to integrate these information for precise and stable endoscopic guidance. To tackle such a challenge, this paper proposes a new framework on the basis of an enhanced particle swarm optimization method to effectively fuse these information for accurate and continuous endoscope localization. The authors use the particle swarm optimization method, which is one of stochastic evolutionary computation algorithms, to effectively fuse the multimodal information including preoperative information (i.e., computed tomography images) as a frame of reference, endoscopic camera videos, and positional sensor measurements (i.e., electromagnetic sensor outputs). Since the evolutionary computation method usually limits its possible premature convergence and evolutionary factors, the authors introduce the current (endoscopic camera and electromagnetic sensor's) observation to boost the particle swarm optimization and also adaptively update evolutionary parameters in accordance with spatial constraints and the current observation, resulting in advantageous performance in the enhanced algorithm. The experimental results demonstrate that the authors' proposed method provides a more accurate and robust endoscopic guidance framework than state-of-the-art methods. The average guidance accuracy of the authors' framework was about 3.0 mm and 5.6° while the previous methods show at least 3.9 mm and 7.0°. The average position and orientation smoothness of their method was 1.0 mm and 1.6°, which is significantly better than the other methods at least with (2.0 mm and 2.6°). Additionally, the average visual quality of the endoscopic guidance was improved to 0.29. A robust electromagnetically guided endoscopy framework was proposed on the basis of an enhanced particle swarm

  2. Robust electromagnetically guided endoscopic procedure using enhanced particle swarm optimization for multimodal information fusion

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Xiongbiao, E-mail: xluo@robarts.ca, E-mail: Ying.Wan@student.uts.edu.au [Robarts Research Institute, Western University, London, Ontario N6A 5K8 (Canada); Wan, Ying, E-mail: xluo@robarts.ca, E-mail: Ying.Wan@student.uts.edu.au; He, Xiangjian [School of Computing and Communications, University of Technology, Sydney, New South Wales 2007 (Australia)

    2015-04-15

    Purpose: Electromagnetically guided endoscopic procedure, which aims at accurately and robustly localizing the endoscope, involves multimodal sensory information during interventions. However, it still remains challenging in how to integrate these information for precise and stable endoscopic guidance. To tackle such a challenge, this paper proposes a new framework on the basis of an enhanced particle swarm optimization method to effectively fuse these information for accurate and continuous endoscope localization. Methods: The authors use the particle swarm optimization method, which is one of stochastic evolutionary computation algorithms, to effectively fuse the multimodal information including preoperative information (i.e., computed tomography images) as a frame of reference, endoscopic camera videos, and positional sensor measurements (i.e., electromagnetic sensor outputs). Since the evolutionary computation method usually limits its possible premature convergence and evolutionary factors, the authors introduce the current (endoscopic camera and electromagnetic sensor’s) observation to boost the particle swarm optimization and also adaptively update evolutionary parameters in accordance with spatial constraints and the current observation, resulting in advantageous performance in the enhanced algorithm. Results: The experimental results demonstrate that the authors’ proposed method provides a more accurate and robust endoscopic guidance framework than state-of-the-art methods. The average guidance accuracy of the authors’ framework was about 3.0 mm and 5.6° while the previous methods show at least 3.9 mm and 7.0°. The average position and orientation smoothness of their method was 1.0 mm and 1.6°, which is significantly better than the other methods at least with (2.0 mm and 2.6°). Additionally, the average visual quality of the endoscopic guidance was improved to 0.29. Conclusions: A robust electromagnetically guided endoscopy framework was

  3. Indoor environment and energy consumption optimization using field measurements and building energy simulation

    DEFF Research Database (Denmark)

    Christensen, Jørgen Erik; Chasapis, Kleanthis; Gazovic, Libor

    2015-01-01

    Modern buildings are usually equipped with advanced climate conditioning systems to ensure comfort of their occupants. However, analysis of their actual operation usually identifies large potential for improvements with respect to their efficiency. Present study investigated potential for improve......, which was used for optimization of building’s performance. Proposed optimization scenarios bring 21-37% reduction on heating consumption and thermal comfort improvement by 7-12%. The approach (procedure) can help to optimize building operation and shorten the adjustment period....

  4. Balanced and optimal bianisotropic particles: maximizing power extracted from electromagnetic fields

    International Nuclear Information System (INIS)

    Ra'di, Younes; Tretyakov, Sergei A

    2013-01-01

    Here we introduce the concept of ‘optimal particles’ for strong interactions with electromagnetic fields. We assume that a particle occupies a given electrically small volume in space and study the required optimal relations between the particle polarizabilities. In these optimal particles, the inclusion shape and material are chosen so that the particles extract the maximum possible power from given incident fields. It appears that for different excitation scenarios the optimal particles are bianisotropic chiral, omega, moving and Tellegen particles. The optimal dimensions of resonant canonical chiral and omega particles are found analytically. Such optimal particles have extreme properties in scattering (e.g., zero backscattering or invisibility). Planar arrays of optimal particles possess extreme properties in reflection and transmission (e.g. total absorption or magnetic-wall response), and volumetric composites of optimal particles realize, for example, such extreme materials as the chiral nihility medium. (paper)

  5. Optimized dose conformation of multi-leaf collimator fields

    International Nuclear Information System (INIS)

    Serago, Christopher F.; Buskirk, Steven J.; Foo, May L.; McLaughlin, Mark P.

    1996-01-01

    Purpose/Objective: Current commercially available multi-leaf collimators (MLC) have leaf widths of about 1 cm. These leaf widths may produce stepped dose gradients at the fields edges at the 50% dose level. Small local perturbations of the dose distribution from the prescribed/expected dose distribution may not be acceptable for some clinical applications. Improvements to the conformation of the MLC dose distribution may be achieved using multiple exposures per MLC field, with either shifting the table/patient position, or rotating the orientation of the MLC jaws between exposures. Material and Methods: Dose distributions for MLC, primary jaws only, and lead alloy block fields were measured with film dosimetry for 6 and 20 MV photon beams in a solid water phantom. Square, circular, and typical clinical prostate, brain, lung, esophagus, and head and neck fields were measured. MLC field shapes were produced using a commercial MLC with a leaf width of 1 cm at the treatment isocenter. The dose per MLC field was delivered in either single (conventional) or multiple exposures. The table(patient) position or the collimator rotation was shifted between exposures when multiple exposure MLC fields were used. Differences in the dose distribution were evaluated at the 90% and 50% isodose level. Displacements of the measured 50% isodose from the prescribed/expected 50% isodose were measured at 5 degree intervals. Results: Measurements of the penumbra at a 10 cm depth for square fields show that using double exposure MLC fields with .5 cm table index decreases the effective penumbra by 1 mm. For clinical shaped fields, displacements between the prescribed/expected 50% isodose and the measured 50% isodose for conventional single exposure MLC fields are measured to be as great as 9 mm, and discrepancies on the order of 5 to 6 mm are common. In contrast, the maximum displacement errors measured with multiple exposure MLC fields are less than 5 mm and rarely more than 4 mm. In some

  6. SUPPORTING THE INDUSTRY BY DEVELOPING A DESIGN GUIDANCE FOR COMPUTER-BASED PROCEDURES FOR FIELD WORKERS

    Energy Technology Data Exchange (ETDEWEB)

    Oxstrand, Johanna; LeBlanc, Katya

    2017-06-01

    The paper-based procedures currently used for nearly all activities in the commercial nuclear power industry have a long history of ensuring safe operation of the plants. However, there is potential to greatly increase efficiency and safety by improving how the human interacts with the procedures, which can be achieved through the use of computer-based procedures (CBPs). A CBP system offers a vast variety of improvements, such as context driven job aids, integrated human performance tools and dynamic step presentation. As a step toward the goal of improving procedure use performance, the U.S. Department of Energy Light Water Reactor Sustainability Program researchers, together with the nuclear industry, have been investigating the possibility and feasibility of replacing current paper-based procedures with CBPs. The main purpose of the CBP research conducted at the Idaho National Laboratory was to provide design guidance to the nuclear industry to be used by both utilities and vendors. After studying existing design guidance for CBP systems, the researchers concluded that the majority of the existing guidance is intended for control room CBP systems, and does not necessarily address the challenges of designing CBP systems for instructions carried out in the field. Further, the guidance is often presented on a high level, which leaves the designer to interpret what is meant by the guidance and how to specifically implement it. The authors developed a design guidance to provide guidance specifically tailored to instructions that are carried out in the field based.

  7. Development of an optimized procedure bridging design and structural analysis codes for the automatized design of the SMART

    International Nuclear Information System (INIS)

    Kim, Tae Wan; Park, Keun Bae; Choi, Suhn; Kim, Kang Soo; Jeong, Kyeong Hoon; Lee, Gyu Mahn

    1998-09-01

    In this report, an optimized design and analysis procedure is established to apply to the SMART (System-integrated Modular Advanced ReacTor) development. The development of an optimized procedure is to minimize the time consumption and engineering effort by squeezing the design and feedback interactions. To achieve this goal, the data and information generated through the design development should be directly transferred to the analysis program with minimum operation. The verification of the design concept requires considerable effort since the communication between the design and analysis involves time consuming stage for the conversion of input information. In this report, an optimized procedure is established bridging the design and analysis stage utilizing the IDEAS, ABAQUS and ANSYS. (author). 3 refs., 2 tabs., 5 figs

  8. Improvement of Low-Frequency Sound Field Obtained by an Optimized Boundary

    Institute of Scientific and Technical Information of China (English)

    JING Lu; ZHU Xiao-tian

    2006-01-01

    An approach based on the finite element analysis was introduced to improve low-frequency sound field. The optimized scatters on the wall redistribute the modes of the room and provide effective diffusion of sound field. The frequency response, eigenfrequency, spatial distribution and transient response were calculated. Experimental data were obtained through a 1:5 scaled set up. The results show that the optimized treatment has a positive effect on sound field and the improvement is obvious.

  9. Optimization of synthesis and quality control procedures for the preparation of 18F-labelled peptides

    International Nuclear Information System (INIS)

    Amartey, J.K.

    2002-01-01

    human cancer cell line in a dose dependent manner as expected. The biodistribution showed that the [ 18 F]-RC-160 bound to tumour xenograft in nude mice. The main objective of the project was to optimize reaction conditions and quality control procedures for prosthetic labelling of peptides. Hence the aims of the project were to: improve fluorination of prosthetic group such as fluorobenzoate, synthesis and isolation of the succinimidyl activated ester of the prosthetic group and reaction conditions to couple the activated ester to a model chemotactic peptide, and to develop an isolation method for the peptide conjugate; perform in vitro and in vivo experiments to ascertain the biological activity of the conjugate; apply the methods and techniques developed to label another biologically active peptide and evaluate its potential application as a cancer detection agent. (author)

  10. Optimization procedures in mammography: First results; Procesos de Optimizacion en Mamografia. Primeros Resultados

    Energy Technology Data Exchange (ETDEWEB)

    Espana Lopez, M. L.; Marcos de Paz, L.; Martin Rincon, C.; Jerez Sainz, I.; Lopez Franco, M. P. [Hospital Universitario de La Princesa. Madrid (Spain)

    2001-07-01

    Optimization procedures in mammography using equipment with a unique target/filter combination can be carried out through such diverse factors as target optical density, technique factors for exposure, screen film combination or processing cycle, in order to obtain an image adequate for the diagnosis with an acceptable risk benefit balance. Diverse studies show an increase in the Standardised Detection Rate of invasive carcinomas with an increase in the optical density among others factors. In our hospital an optimisation process has been established, and as previous step, the target optical density has been increased up to 1,4 DO. The aim of this paper is to value the impact of optical density variation as much in the quality of image as in the entrance surface dose and the average dose to the glandular tissue, comparing them with the results obtained in a previous study. The study has been carried out in a sample of 106 patients, with an average age of 53,4 years, considering 212 clinical images corresponding to the two projections of a same breast with an average compressed thickness of 4,86 cm. An increase of 16,6% on the entrance surface dose and 18% on the average dose to the glandular tissue has been recorded. All the clinical images has been evaluated for the physician as adequate for diagnosis. (Author) 16 refs.

  11. ELF field in the proximity of complex power line configuration measurement procedures

    International Nuclear Information System (INIS)

    Benes, M.; Comelli, M.; Villalta, R.

    2006-01-01

    The issue of how to measure magnetic induction fields generated by various power line configurations, when there are several power lines that run across the same exposure area, has become a matter of interest and study within the Regional Environment Protection Agency of Friuli Venezia Giulia. In classifying the various power line typologies the definition of double circuit line was given: in this instance the magnetic field is determined by knowing the electrical and geometric parameters of the line. In the case of independent lines instead, the field is undetermined. It is therefore pointed out how, in the latter case, extracting projected information from a set of measurements of the magnetic field alone is impossible. Making measurements throughout the territory of service has in several cases offered the opportunity to define standard operational procedures. (authors)

  12. Optimization of a pulsed-field gel electrophoresis for molecular typing of Proteus mirabilis

    Directory of Open Access Journals (Sweden)

    Alper Karagöz

    2013-09-01

    Full Text Available Objective: For the detection of outbreaks caused byProteus mirabilis, strains clonal relations are determinedmethods as “pulsed-field gel electrophoresis (PFGE”.The aim of this study was optimization of a pulsed-fieldgel electrophoresis for molecular typing of P. mirabilis.Methods: In this study, PFGE’ protocol is optimized foruse in molecular typing of P. mirabilis. Phylogenetic analyzesof strains were evaluated with Bionumerics softwaresystem (version 6.01; Applied Maths, Sint-Martens-Latem, Belgium.Results: This protocol compared with Gram-negativebacteria PFGE protocols, NotI enzyme is suitable for thisbacterium. Electrophoresis conditions should be revealedas; - block 1: initial pulse duration 1 sec, ending pulseduration 30 sec, striking angle 120°, the current 6 V/cm2,temperature 14°C, time 8 hours; - block 2: initial pulseduration 30 sec, ending pulse duration 70 sec, strikingangle 120°, the current 6 V/cm2, temperature 14°C, time16 hours; - TBE, pH=8.4.Conclusion: P. mirabilis strains were typed by PFGE andBionumerics analysis program were determined clonal relationships.The procedure was simple, reproducible andsuitable for these bacteria. Also it was evaluated, becauseof reducing time, the solution volumes and enzymes canbe economically. Outbreaks of nosocomial infections dueto bacteria studied assessment and the potential to provideuseful information about the degree of prevalence.This optimized protocol is allowed different centers’ PFGEresults to compare with other laboratories results. J ClinExp Invest 2013; 4 (3: 306-312Key words: Proteus mirabilis, molecular typing, pulsedfieldgel electrophoresis.

  13. Introduction of regulatory and licensing procedures of some OECD countries in the field of decommissioning

    International Nuclear Information System (INIS)

    Benedekfi, O.; Zagyvai, P.; Czifrus, S.; Ormai, P.; Danko, G.

    2001-01-01

    In the OECD countries more than 50 nuclear power plants will have to be closed in the beginning of the next century since their licenses expire. For this reason it is very important to establish reasonable regulations in the field of decommissioning. In this poster firstly we define the basic principles related to decommissioning. Then we account on our survey of the situation of the regulatory and licensing procedures in some OECD countries. Finally we compare the results. (authors)

  14. Field redevelopment optimization to unlock reserves and enhance production

    Directory of Open Access Journals (Sweden)

    AHMED AL-HASHAMI

    2013-09-01

    Full Text Available A cluster area "H" consists of 4 carbonate gas fields producing dry gas from N-A reservoir in the Northern area of Oman. These fields are producing with different maturity levels since 1968. An FDP (Field Development Plan study was done in 2006 which proposed drilling of 7 additional vertical wells beside the already existing 5 wells to develop the reserves and enhance gas production from the fields. The FDP well planning was based on a seismic amplitude "Qualitative Interpretation (QI" study that recommended drilling the areas with high amplitudes as an indication for gas presence, and it ignored the low amplitude areas even if it is structurally high. A follow up study was conducted in 2010 for "H" area fields using the same seismic data and the well data drilled post FDP. The new static and dynamic work revealed the wrong aspect of the 2006 QI study, and proved with evidence from well logs and production data that low seismic amplitudes in high structural areas have sweet spots of good reservoir quality rock. This has led to changing the old appraisal strategy and planning more wells in low amplitude areas with high structure and hence discovering new blocks that increased the reserves of the fields.Furthermore, water production in these fields started much earlier than FDP expectation. The subsurface team have integrated deeply with the operation team and started a project to find new solutions to handle the water production and enhance the gas rate. The subsurface team also started drilling horizontal wells in the fields to increase the UR, delay the water production and also reduce the wells total CAPEX by drilling less horizontal wells compared to many vertical as they have higher production and recovery. These subsurface and surface activities have successfully helped to stabilize and increase the production of "H" area cluster by developing more reserves and handling the water production.

  15. Vibrational self-consistent field theory using optimized curvilinear coordinates.

    Science.gov (United States)

    Bulik, Ireneusz W; Frisch, Michael J; Vaccaro, Patrick H

    2017-07-28

    A vibrational SCF model is presented in which the functions forming the single-mode functions in the product wavefunction are expressed in terms of internal coordinates and the coordinates used for each mode are optimized variationally. This model involves no approximations to the kinetic energy operator and does not require a Taylor-series expansion of the potential. The non-linear optimization of coordinates is found to give much better product wavefunctions than the limited variations considered in most previous applications of SCF methods to vibrational problems. The approach is tested using published potential energy surfaces for water, ammonia, and formaldehyde. Variational flexibility allowed in the current ansätze results in excellent zero-point energies expressed through single-product states and accurate fundamental transition frequencies realized by short configuration-interaction expansions. Fully variational optimization of single-product states for excited vibrational levels also is discussed. The highlighted methodology constitutes an excellent starting point for more sophisticated treatments, as the bulk characteristics of many-mode coupling are accounted for efficiently in terms of compact wavefunctions (as evident from the accurate prediction of transition frequencies).

  16. Radiation field distribution within the room for three commonly-used interventional procedures

    International Nuclear Information System (INIS)

    Liu Changcai; Zhang Lin; Min Nan; Lu Feng; Li Quantai; Deng Daping; Chen Yue; Zhu Jianguo

    2014-01-01

    Objective: To detect the radiation field distribution within the room for three commonly-used interventional procedures, in order to provide basic data for the radiation protection and safe operation of staff involved in interventional radiology. Methods: The thermoluminescent dosemeters (TLDs) were placed in different points on the horizontal plane around the interventional table and the vertical plane where the staff often stayed. Based on the selected experimental conditions, the TLDs were grouped to be irradiated. After the experiment, the TLDs were measured in the laboratory to calculate the doses of radiation field. Results: Data obtained at the same position followed basically as cardiovascular intervention > cerebrovascular intervention > liver intervention. Intervention of same type at the same position followed as high-dose group > mid-dose group > low-dose group. These results were consistent with the useful beam doses, and proportional to the fluoroscopy time. A few data with exception were due to measurement error or experimental error. Conclusions: Cerebrovascular and liver interventional procedures resulted in the relatively low radiation doses. The radiation doses at the distance of more than 3 m can be negligible. For cardiovascular interventional procedure, with the decrease of the distance from the X-ray tube, the dose decreased. In the radiation field,the operator, the first assistant and second assistant would exposed to higher dose on the standing points while patients receive lower doses in the head and feet direction. (authors)

  17. The human error rate assessment and optimizing system HEROS - a new procedure for evaluating and optimizing the man-machine interface in PSA

    International Nuclear Information System (INIS)

    Richei, A.; Hauptmanns, U.; Unger, H.

    2001-01-01

    A new procedure allowing the probabilistic evaluation and optimization of the man-machine system is presented. This procedure and the resulting expert system HEROS, which is an acronym for Human Error Rate Assessment and Optimizing System, is based on the fuzzy set theory. Most of the well-known procedures employed for the probabilistic evaluation of human factors involve the use of vague linguistic statements on performance shaping factors to select and to modify basic human error probabilities from the associated databases. This implies a large portion of subjectivity. Vague statements are expressed here in terms of fuzzy numbers or intervals which allow mathematical operations to be performed on them. A model of the man-machine system is the basis of the procedure. A fuzzy rule-based expert system was derived from ergonomic and psychological studies. Hence, it does not rely on a database, whose transferability to situations different from its origin is questionable. In this way, subjective elements are eliminated to a large extent. HEROS facilitates the importance analysis for the evaluation of human factors, which is necessary for optimizing the man-machine system. HEROS is applied to the analysis of a simple diagnosis of task of the operating personnel in a nuclear power plant

  18. Multiphysics field analysis and multiobjective design optimization: a benchmark problem

    Czech Academy of Sciences Publication Activity Database

    di Barba, P.; Doležel, Ivo; Karban, P.; Kůs, P.; Mach, F.; Mognaschi, M. E.; Savini, A.

    2014-01-01

    Roč. 22, č. 7 (2014), s. 1214-1225 ISSN 1741-5977 R&D Projects: GA ČR(CZ) GAP102/11/0498 Institutional support: RVO:61388998 Keywords : coupled-field problems * finite-element analysis * hp-FEM adaptation Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.868, year: 2014

  19. Optimized 425MHz passive wireless magnetic field sensor

    KAUST Repository

    Li, Bodong; Kosel, Jü rgen

    2014-01-01

    -X cut LiNbO3 LiNbO3 substrate. The integrated sensor is characterized with a network analyzer through an S-parameter measurement. Upon the application of a magnetic field, a maximum magnitude change and phase shift of 7.8 dB and 27 degree, respectively

  20. Optimization of labelling procedure of 188rE-DMSA(v)

    International Nuclear Information System (INIS)

    Dantas, Danielle M.; Brambilla, Tania P.; Reis, Nicoli F.; Osso Junior, Joao A.

    2011-01-01

    Radionuclide therapy (RNT) is emerging as an important tool of nuclear medicine. Apart from the well established 131 I, several other promising radionuclides have been identified, among them 188 Re, 90 Y and 177 Lu. 188 Re has received a lot of attention in the past decade, due to its favourable nuclear characteristics [t 1/2 16.9 h, E b eta m ax 2.12 MeV and E g amma 155 keV (15%) suitable for imaging, including the fact that it is carrier-free and can be obtained cost-effectively through the generator 188 W- 188 Re. Biodistribution studies of 188 Re-DMSA(V) have shown that its general pharmacokinetic properties are similar to that of 99m Tc-DMSA(V), so this agent could be used for targeted radiotherapy of medullary thyroid carcinoma, bone metastases, soft tissue and others tumors. The aim of this work is to evaluate two labeling procedures for the preparation of 188 Re-DMSA(V). The first method was prepared using a commercial kit of DMSA(III) for labeling with 99m Tc at high temperature (100 deg C). The second method was prepared in a vial containing 2.5 mg of DMSA, 1.00 mg of SnCl 2 .2H 2 O and 10 mg of sodium oxalate, 10 mg of cyclodextrin, in a total volume of 2.0 mL. The pH was adjusted to 3 with 37% HCl. After labeling the solution was stirred and incubated for 30 min at room temperature. The radiochemical purity was determined using TLC-SG developed with two different solvent systems: Acetone and glycine. Preliminary results for both methods of labeling 188 Re-DMSA(V) showed that the labeling yield was >95%. Further experiments are also necessary to optimize the labeling methodology of 188 Re-DMSA(V).author)

  1. Development and Optimization of a Flocculation Procedure for Improved Solid-Liquid Separation of Digested Biomass

    Energy Technology Data Exchange (ETDEWEB)

    Patton, Caroline; Lischeske, James J.; Sievers, David A.

    2015-11-03

    One viable treatment method for conversion of lignocellulosic biomass to biofuels begins with saccharification (thermochemical pretreatment and enzymatic hydrolysis), followed by fermentation or catalytic upgrading to fuels such as ethanol, butanol, or other hydrocarbons. The post-hydrolysis slurry is typically 4-8 percent insoluble solids, predominantly consisting of lignin. Suspended solids are known to inhibit fermentation as well as poison catalysts and obstruct flow in catalyst beds. Thus a solid-liquid separation following enzymatic hydrolysis would be highly favorable for process economics, however the material is not easily separated by filtration or gravimetric methods. Use of a polyacrylamide flocculant to bind the suspended particles in a corn stover hydrolyzate slurry into larger flocs (1-2mm diameter) has been found to be extremely helpful in improving separation. Recent and ongoing research on novel pretreatment methods yields hydrolyzate material with diverse characteristics. Therefore, we need a thorough understanding of rapid and successful flocculation design in order to quickly achieve process design goals. In this study potential indicators of flocculation performance were investigated in order to develop a rapid analysis method for flocculation procedure in the context of a novel hydrolyzate material. Flocculation conditions were optimized on flocculant type and loading, pH, and mixing time. Filtration flux of the hydrolyzate slurry was improved 170-fold using a cationic polyacrylamide flocculant with a dosing of approximately 22 mg flocculant/g insoluble solids at an approximate pH of 3. With cake washing, sugar recovery exceeded 90 percent with asymptotic yield at 15 L wash water/kg insoluble solids.

  2. An adaptive, individualized fMRI delay discounting procedure to increase flexibility and optimize scanner time.

    Science.gov (United States)

    Koffarnus, Mikhail N; Deshpande, Harshawardhan U; Lisinski, Jonathan M; Eklund, Anders; Bickel, Warren K; LaConte, Stephen M

    2017-11-01

    Research on the rate at which people discount the value of future rewards has become increasingly prevalent as discount rate has been shown to be associated with many unhealthy patterns of behavior such as drug abuse, gambling, and overeating. fMRI research points to a fronto-parietal-limbic pathway that is active during decisions between smaller amounts of money now and larger amounts available after a delay. Researchers in this area have used different variants of delay discounting tasks and reported various contrasts between choice trials of different types from these tasks. For instance, researchers have compared 1) choices of delayed monetary amounts to choices of the immediate monetary amounts, 2) 'hard' choices made near one's point of indifference to 'easy' choices that require little thought, and 3) trials where an immediate choice is available versus trials where one is unavailable, regardless of actual eventual choice. These differences in procedure and analysis make comparison of results across studies difficult. In the present experiment, we designed a delay discounting task with the intended capability of being able to construct contrasts of all three comparisons listed above while optimizing scanning time to reduce costs and avoid participant fatigue. This was accomplished with an algorithm that customized the choice trials presented to each participant with the goal of equalizing choice trials of each type. We compared this task, which we refer to here as the individualized discounting task (IDT), to two other delay discounting tasks previously reported in the literature (McClure et al., 2004; Amlung et al., 2014) in 18 participants. Results show that the IDT can examine each of the three contrasts mentioned above, while yielding a similar degree of activation as the reference tasks. This suggests that this new task could be used in delay discounting fMRI studies to allow researchers to more easily compare their results to a majority of previous

  3. Optimization of a Pre-MEKC Separation SPE Procedure for Steroid Molecules in Human Urine Samples

    Directory of Open Access Journals (Sweden)

    Ilona Olędzka

    2013-11-01

    Full Text Available Many steroid hormones can be considered as potential biomarkers and their determination in body fluids can create opportunities for the rapid diagnosis of many diseases and disorders of the human body. Most existing methods for the determination of steroids are usually time- and labor-consuming and quite costly. Therefore, the aim of analytical laboratories is to develop a new, relatively low-cost and rapid implementation methodology for their determination in biological samples. Due to the fact that there is little literature data on concentrations of steroid hormones in urine samples, we have made attempts at the electrophoretic determination of these compounds. For this purpose, an extraction procedure for the optimized separation and simultaneous determination of seven steroid hormones in urine samples has been investigated. The isolation of analytes from biological samples was performed by liquid-liquid extraction (LLE with dichloromethane and compared to solid phase extraction (SPE with C18 and hydrophilic-lipophilic balance (HLB columns. To separate all the analytes a micellar electrokinetic capillary chromatography (MECK technique was employed. For full separation of all the analytes a running buffer (pH 9.2, composed of 10 mM sodium tetraborate decahydrate (borax, 50 mM sodium dodecyl sulfate (SDS, and 10% methanol was selected. The methodology developed in this work for the determination of steroid hormones meets all the requirements of analytical methods. The applicability of the method has been confirmed for the analysis of urine samples collected from volunteers—both men and women (students, amateur bodybuilders, using and not applying steroid doping. The data obtained during this work can be successfully used for further research on the determination of steroid hormones in urine samples.

  4. Performance evaluation of different types of particle representation procedures of Particle Swarm Optimization in Job-shop Scheduling Problems

    Science.gov (United States)

    Izah Anuar, Nurul; Saptari, Adi

    2016-02-01

    This paper addresses the types of particle representation (encoding) procedures in a population-based stochastic optimization technique in solving scheduling problems known in the job-shop manufacturing environment. It intends to evaluate and compare the performance of different particle representation procedures in Particle Swarm Optimization (PSO) in the case of solving Job-shop Scheduling Problems (JSP). Particle representation procedures refer to the mapping between the particle position in PSO and the scheduling solution in JSP. It is an important step to be carried out so that each particle in PSO can represent a schedule in JSP. Three procedures such as Operation and Particle Position Sequence (OPPS), random keys representation and random-key encoding scheme are used in this study. These procedures have been tested on FT06 and FT10 benchmark problems available in the OR-Library, where the objective function is to minimize the makespan by the use of MATLAB software. Based on the experimental results, it is discovered that OPPS gives the best performance in solving both benchmark problems. The contribution of this paper is the fact that it demonstrates to the practitioners involved in complex scheduling problems that different particle representation procedures can have significant effects on the performance of PSO in solving JSP.

  5. Optimization study on the magnetic field of superconducting Halbach Array magnet

    Science.gov (United States)

    Shen, Boyang; Geng, Jianzhao; Li, Chao; Zhang, Xiuchang; Fu, Lin; Zhang, Heng; Ma, Jun; Coombs, T. A.

    2017-07-01

    This paper presents the optimization on the strength and homogeneity of magnetic field from superconducting Halbach Array magnet. Conventional Halbach Array uses a special arrangement of permanent magnets which can generate homogeneous magnetic field. Superconducting Halbach Array utilizes High Temperature Superconductor (HTS) to construct an electromagnet to work below its critical temperature, which performs equivalently to the permanent magnet based Halbach Array. The simulations of superconducting Halbach Array were carried out using H-formulation based on B-dependent critical current density and bulk approximation, with the FEM platform COMSOL Multiphysics. The optimization focused on the coils' location, as well as the geometry and numbers of coils on the premise of maintaining the total amount of superconductor. Results show Halbach Array configuration based superconducting magnet is able to generate the magnetic field with intensity over 1 Tesla and improved homogeneity using proper optimization methods. Mathematical relation of these optimization parameters with the intensity and homogeneity of magnetic field was developed.

  6. Optimized 425MHz passive wireless magnetic field sensor

    KAUST Repository

    Li, Bodong

    2014-06-01

    A passive, magnetic field sensor consisting of a 425 MHz surface acoustic wave device loaded with a giant magnetoimpedance element is developed. The GMI element with a multilayer structure composed of Ni80Fe 20/Cu/Ni80Fe20, is fabricated on a 128° Y-X cut LiNbO3 LiNbO3 substrate. The integrated sensor is characterized with a network analyzer through an S-parameter measurement. Upon the application of a magnetic field, a maximum magnitude change and phase shift of 7.8 dB and 27 degree, respectively, are observed. Within the linear region, the magnetic sensitivity is 1.6 dB/Oe and 5 deg/Oe. © 2014 IEEE.

  7. Planning and Optimization of Wireless LANs through Field Measurements

    OpenAIRE

    Mongia, Puneet Kumar; Singh, B. J.

    2013-01-01

    In this paper, the field measurements of signal strength taken at the frequency of 2432 MHz in indoor & outdoor environments are presented and analyzed. The received signal levels from the base station were monitored manually. Total coverage area considered for the measurement campaign consisted of a mixture of different propagation environments. Based on the experimental data obtained, path loss exponent and standard deviation of signal strength variability are derived. It is shown that the ...

  8. A Two-Mode Mean-Field Optimal Switching Problem for the Full Balance Sheet

    Directory of Open Access Journals (Sweden)

    Boualem Djehiche

    2014-01-01

    a two-mode optimal switching problem of mean-field type, which can be described by a system of Snell envelopes where the obstacles are interconnected and nonlinear. The main result of the paper is a proof of a continuous minimal solution to the system of Snell envelopes, as well as the full characterization of the optimal switching strategy.

  9. An optimized absorbing potential for ultrafast, strong-field problems

    Science.gov (United States)

    Yu, Youliang; Esry, B. D.

    2018-05-01

    Theoretical treatments of strong-field physics have long relied on the numerical solution of the time-dependent Schrödinger equation. The most effective such treatments utilize a discrete spatial representation—a grid. Since most strong-field observables relate to the continuum portion of the wave function, the boundaries of the grid—which act as hard walls and thus cause reflection—can substantially impact the observables. Special care thus needs to be taken. While there exist a number of attempts to solve this problem—e.g., complex absorbing potentials and masking functions, exterior complex scaling, and coordinate scaling—none of them are completely satisfactory. The first of these is arguably the most popular, but it consumes a substantial fraction of the computing resources in any given calculation. Worse, this fraction grows with the dimensionality of the problem. In addition, no systematic way to design such a potential has been used in the strong-field community. In this work, we address these issues and find a much better solution. By comparing with previous widely used absorbing potentials, we find a factor of 3–4 reduction in the absorption range, given the same level of absorption over a specified energy interval.

  10. Optimal orientation field to manufacture magnetostrictive composites with high magnetostrictive performance

    International Nuclear Information System (INIS)

    Dong Xufeng; Ou Jinping; Guan Xinchun; Qi Min

    2010-01-01

    Magnetostrictive properties have relationship with the applied orientation field during the preparation of giant magnetostrictive composites. To understand the dependence of the optimal orientation field on particle volume fraction, composites with 20%, 30% and 50% particles by volume were fabricated by distributing Terfenol-D particles in an unsaturated polyester resin under various orientation fields. Their magnetostrictive properties were tested without pre-stress at room temperature. The results indicate that as the particle volume fraction increases, the optimal orientation field increases. The main reason for this phenomenon is the packing density for the composites with higher particle volume fraction is larger than that for those with lower particle content.

  11. Optimal orientation field to manufacture magnetostrictive composites with high magnetostrictive performance

    Energy Technology Data Exchange (ETDEWEB)

    Dong Xufeng, E-mail: dongxf@dlut.edu.c [School of Materials Science and Engineering, Dalian University of Technology, Dalian, Liaoning 116024 (China); Ou Jinping [School of Civil and Hydraulic Engineering, Dalian University of Technology, Dalian, Liaoning 116024 (China); School of Civil Engineering, Harbin Institute of Technology, Harbin, Heilongjiang 150090 (China); Guan Xinchun [School of Civil Engineering, Harbin Institute of Technology, Harbin, Heilongjiang 150090 (China); Qi Min [School of Materials Science and Engineering, Dalian University of Technology, Dalian, Liaoning 116024 (China)

    2010-11-15

    Magnetostrictive properties have relationship with the applied orientation field during the preparation of giant magnetostrictive composites. To understand the dependence of the optimal orientation field on particle volume fraction, composites with 20%, 30% and 50% particles by volume were fabricated by distributing Terfenol-D particles in an unsaturated polyester resin under various orientation fields. Their magnetostrictive properties were tested without pre-stress at room temperature. The results indicate that as the particle volume fraction increases, the optimal orientation field increases. The main reason for this phenomenon is the packing density for the composites with higher particle volume fraction is larger than that for those with lower particle content.

  12. Standard and procedures for measuring and evaluating of the field electromagnetic signals

    International Nuclear Information System (INIS)

    Fallas Cordero, Oscar

    2007-01-01

    Rules and procedures are developed for measuring the intensity of electromagnetic field signals produced by public commercial broadcasters. International and national standards applicable to existing broadcasting area were investigated. The Manual para la Comprobacion Tecnica de las Emisiones of the International Radio Consultative Committee of the International Telecommunications Union was used for reference in the procedures. It was worked in coordination with the Control Nacional de Radio and Radio U to obtain information and to study the teams to present a measurement system for laboratory that meets with the standards suggested and which can encompass a wide range of transmission services. Finally agreed with the analysis and research work done, a series of recommendations were made for improvement, which are considered to implement them in medium and long time. (author) [es

  13. An analytical model for the vertical electric field distribution and optimization of high voltage REBULF LDMOS

    International Nuclear Information System (INIS)

    Hu Xia-Rong; Lü Rui

    2014-01-01

    In this paper, an analytical model for the vertical electric field distribution and optimization of a high voltage-reduced bulk field (REBULF) lateral double-diffused metal—oxide-semiconductor (LDMOS) transistor is presented. The dependences of the breakdown voltage on the buried n-layer depth, thickness, and doping concentration are discussed in detail. The REBULF criterion and the optimal vertical electric field distribution condition are derived on the basis of the optimization of the electric field distribution. The breakdown voltage of the REBULF LDMOS transistor is always higher than that of a single reduced surface field (RESURF) LDMOS transistor, and both analytical and numerical results show that it is better to make a thick n-layer buried deep into the p-substrate. (interdisciplinary physics and related areas of science and technology)

  14. An analytical-numerical comprehensive method for optimizing the fringing magnetic field

    International Nuclear Information System (INIS)

    Xiao Meiqin; Mao Naifeng

    1991-01-01

    The criterion of optimizing the fringing magnetic field is discussed, and an analytical-numerical comprehensive method for realizing the optimization is introduced. The method mentioned above consists of two parts, the analytical part calculates the field of the shims, which corrects the fringing magnetic field by using uniform magnetizing method; the numerical part fulfils the whole calculation of the field distribution by solving the equation of magnetic vector potential A within the region covered by arbitrary triangular meshes with the aid of finite difference method and successive over relaxation method. On the basis of the method, the optimization of the fringing magnetic field for a large-scale electromagnetic isotope separator is finished

  15. Optimal Background Attenuation for Fielded Radiation Detection Systems

    International Nuclear Information System (INIS)

    Robinson, Sean M.; Kaye, William R.; Schweppe, John E.; Siciliano, Edward R.

    2006-01-01

    Radiation detectors are often placed in positions difficult to shield from the effects of terrestrial background. This is particularly true in the case of Radiation Portal Monitor (RPM) systems, as their wide viewing angle and outdoor installations make them susceptible to terrestrial background from the surrounding area. A low background is desired in most cases, especially when the background noise is of comparable strength to the signal of interest. The problem of shielding a generalized RPM from terrestrial background is considered. Various detector and shielding scenarios are modeled with the Monte-Carlo N Particle (MCNP) computer code. Amounts of nominal-density shielding needed to attenuate the terrestrial background to varying degrees are given, along with optimal shielding geometry to be used in areas where natural shielding is limited, and where radiation detection must occur in the presence of natural background. Common shielding solutions such as steel plating are evaluated based on the signal to noise ratio and the benefits are weighed against the incremental cost.

  16. Optimal Background Attenuation for Fielded Spectroscopic Detection Systems

    International Nuclear Information System (INIS)

    Robinson, Sean M.; Ashbaker, Eric D.; Schweppe, John E.; Siciliano, Edward R.

    2007-01-01

    Radiation detectors are often placed in positions difficult to shield from the effects of terrestrial background gamma radiation. This is particularly true in the case of Radiation Portal Monitor (RPM) systems, as their wide viewing angle and outdoor installations make them susceptible to radiation from the surrounding area. Reducing this source of background can improve gross-count detection capabilities in the current generation of non-spectroscopic RPM's as well as source identification capabilities in the next generation of spectroscopic RPM's. To provide guidance for designing such systems, the problem of shielding a general spectroscopic-capable RPM system from terrestrial gamma radiation is considered. This analysis is carried out by template matching algorithms, to determine and isolate a set of non-threat isotopes typically present in the commerce stream. Various model detector and shielding scenarios are calculated using the Monte-Carlo N Particle (MCNP) computer code. Amounts of nominal-density shielding needed to increase the probability of detection for an ensemble of illicit sources are given. Common shielding solutions such as steel plating are evaluated based on the probability of detection for 3 particular illicit sources of interest, and the benefits are weighed against the incremental cost of shielding. Previous work has provided optimal shielding scenarios for RPMs based on gross-counting measurements, and those same solutions (shielding the internal detector cavity, direct shielding of the ground between the detectors, and the addition of collimators) are examined with respect to their utility to improving spectroscopic detection

  17. Optimization of the process of pressing safflower seeds in an ultrasonic field

    Directory of Open Access Journals (Sweden)

    S. T. Antipov

    2017-01-01

    Full Text Available The article gives a mathematical description of the process of pressing safflower seeds in an ultrasonic field in the form of a regression equation found by static methods on the basis of experiments and described by a polynomial of the second degree. As the main factors influencing the efficiency of the process, the ultrasound frequency, the amplitude of the ultrasound, the pressure and the press created in the green chamber were selected. And as a criterion for assessing the effect of the selected parameters, the residual oil content of the cake is used. To assess the adequacy of the mathematical model, the variance analysis (ANOVA of the experiment in the Design Expert v. 10 and the regression equation is obtained, the analysis of which allowed us to identify the factors that most influenced the process under consideration. Found that when the pressure in the press to a value higher than 14 MPa, a further increase in efficiency was observed together with increased values as the ultrasound frequency and its amplitude. The maximum and most effective value residual oil content in oil cake obtained in the frequency 35-40 Hz and amplitude of more than 40 mm and the pressure in the press from 10 to 11 MPa. which are obviously directly dependent on the behavior of grain and movement of its internal parts during the supply of the ultrasound. Graphical interpretation of the equation is represented by curves of equal values and response surfaces for input parameters. A numerical and graphical optimization procedure is also proposed to predict the optimal level of input factors and to obtain the maximum yield of oil relative to the mass of the original feed. To test the adequacy of the model, the results of a number of parallel experiments are presented that fall within the calculated confidence intervals for all quality criteria.

  18. Fire-tube immersion heater optimization program and field heater audit program

    Energy Technology Data Exchange (ETDEWEB)

    Croteau, P. [Petro-Canada, Calgary, AB (Canada)

    2007-07-01

    This presentation provided an overview of the top 5 priorities for emission reduction and eco-efficiency by the Petroleum Technology Alliance of Canada (PTAC). These included venting of methane emissions; fuel consumption in reciprocating engines; fuel consumption in fired heaters; flaring and incineration; and fugitive emissions. It described the common concern for many upstream operating companies as being energy consumption associated with immersion heaters. PTAC fire-tube heater and line heater studies were presented. Combustion efficiency was discussed in terms of excess air, fire-tube selection, heat flux rate, and reliability guidelines. Other topics included heat transfer and fire-tube design; burner selection; burner duty cycle; heater tune up inspection procedure; and insulation. Two other programs were also discussed, notably a Petro-Canada fire-tube immersion heater optimization program and the field audit program run by Natural Resources Canada. It was concluded that improved efficiency involves training; managing excess air in combustion; managing the burner duty cycle; striving for 82 per cent combustion efficiency; and providing adequate insulation to reduce energy demand. tabs., figs.

  19. Optimization of labelling procedure of {sup 188}rE-DMSA(v)

    Energy Technology Data Exchange (ETDEWEB)

    Dantas, Danielle M.; Brambilla, Tania P.; Reis, Nicoli F.; Osso Junior, Joao A., E-mail: jaosso@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Radionuclide therapy (RNT) is emerging as an important tool of nuclear medicine. Apart from the well established {sup 131}I, several other promising radionuclides have been identified, among them {sup 188}Re, {sup 90}Y and {sup 177}Lu. {sup 188}Re has received a lot of attention in the past decade, due to its favourable nuclear characteristics [t{sub 1/2} 16.9 h, E{sub b}eta{sub m}ax 2.12 MeV and E{sub g}amma 155 keV (15%) suitable for imaging, including the fact that it is carrier-free and can be obtained cost-effectively through the generator {sup 188}W-{sup 188}Re. Biodistribution studies of {sup 188}Re-DMSA(V) have shown that its general pharmacokinetic properties are similar to that of {sup 99m}Tc-DMSA(V), so this agent could be used for targeted radiotherapy of medullary thyroid carcinoma, bone metastases, soft tissue and others tumors. The aim of this work is to evaluate two labeling procedures for the preparation of {sup 188}Re-DMSA(V). The first method was prepared using a commercial kit of DMSA(III) for labeling with {sup 99m}Tc at high temperature (100 deg C). The second method was prepared in a vial containing 2.5 mg of DMSA, 1.00 mg of SnCl{sub 2}.2H{sub 2}O and 10 mg of sodium oxalate, 10 mg of cyclodextrin, in a total volume of 2.0 mL. The pH was adjusted to 3 with 37% HCl. After labeling the solution was stirred and incubated for 30 min at room temperature. The radiochemical purity was determined using TLC-SG developed with two different solvent systems: Acetone and glycine. Preliminary results for both methods of labeling {sup 188}Re-DMSA(V) showed that the labeling yield was >95%. Further experiments are also necessary to optimize the labeling methodology of {sup 188}Re-DMSA(V).author)

  20. Enhanced Particle Swarm Optimization Algorithm: Efficient Training of ReaxFF Reactive Force Fields.

    Science.gov (United States)

    Furman, David; Carmeli, Benny; Zeiri, Yehuda; Kosloff, Ronnie

    2018-05-04

    Particle swarm optimization is a powerful metaheuristic population-based global optimization algorithm. However, when applied to non-separable objective functions its performance on multimodal landscapes is significantly degraded. Here we show that a significant improvement in the search quality and efficiency on multimodal functions can be achieved by enhancing the basic rotation-invariant particle swarm optimization algorithm with isotropic Gaussian mutation operators. The new algorithm demonstrates a superior performance across several nonlinear, multimodal benchmark functions compared to the rotation-invariant Particle Swam Optimization (PSO) algorithm and the well-established simulated annealing and sequential one-parameter parabolic interpolation methods. A search for the optimal set of parameters for the dispersion interaction model in ReaxFF-lg reactive force field is carried out with respect to accurate DFT-TS calculations. The resulting optimized force field accurately describes the equations of state of several high-energy molecular crystals where such interactions are of crucial importance. The improved algorithm also presents a better performance compared to a Genetic Algorithm optimization method in the optimization of a ReaxFF-lg correction model parameters. The computational framework is implemented in a standalone C++ code that allows a straightforward development of ReaxFF reactive force fields.

  1. Topology optimization based design of unilateral NMR for generating a remote homogeneous field.

    Science.gov (United States)

    Wang, Qi; Gao, Renjing; Liu, Shutian

    2017-06-01

    This paper presents a topology optimization based design method for the design of unilateral nuclear magnetic resonance (NMR), with which a remote homogeneous field can be obtained. The topology optimization is actualized by seeking out the optimal layout of ferromagnetic materials within a given design domain. The design objective is defined as generating a sensitive magnetic field with optimal homogeneity and maximal field strength within a required region of interest (ROI). The sensitivity of the objective function with respect to the design variables is derived and the method for solving the optimization problem is presented. A design example is provided to illustrate the utility of the design method, specifically the ability to improve the quality of the magnetic field over the required ROI by determining the optimal structural topology for the ferromagnetic poles. Both in simulations and experiments, the sensitive region of the magnetic field achieves about 2 times larger than that of the reference design, validating validates the feasibility of the design method. Copyright © 2017. Published by Elsevier Inc.

  2. Optimal control of quantum systems: Origins of inherent robustness to control field fluctuations

    International Nuclear Information System (INIS)

    Rabitz, Herschel

    2002-01-01

    The impact of control field fluctuations on the optimal manipulation of quantum dynamics phenomena is investigated. The quantum system is driven by an optimal control field, with the physical focus on the evolving expectation value of an observable operator. A relationship is shown to exist between the system dynamics and the control field fluctuations, wherein the process of seeking optimal performance assures an inherent degree of system robustness to such fluctuations. The presence of significant field fluctuations breaks down the evolution of the observable expectation value into a sequence of partially coherent robust steps. Robustness occurs because the optimization process reduces sensitivity to noise-driven quantum system fluctuations by taking advantage of the observable expectation value being bilinear in the evolution operator and its adjoint. The consequences of this inherent robustness are discussed in the light of recent experiments and numerical simulations on the optimal control of quantum phenomena. The analysis in this paper bodes well for the future success of closed-loop quantum optimal control experiments, even in the presence of reasonable levels of field fluctuations

  3. Developing Field Test Procedures for Chloride Stress Corrosion Cracking in the Arabian Gulf

    Directory of Open Access Journals (Sweden)

    Hanan Farhat

    2018-01-01

    Full Text Available Oil and gas production and petrochemical plants in the Arabian Gulf are exposed to severe environmental conditions of high temperature and humidity. This makes these plants susceptible to chloride-induced stress corrosion cracking (CSCC. The laboratory testing fails to provide the exact field environmental conditions. A cost efficient field test setup for CSCC was designed and developed for the Arabian Gulf. The setup included designing self-sustained loading devices, samples, and sample racks. The samples were exposed to a stress equivalent to 80% and 100% of their yield strength. This paper describes the developed test procedures to establish testing with high level of accuracy and repeatability. It also discusses the design aspects and the challenges that were met.

  4. Adapting crop management practices to climate change: Modeling optimal solutions at the field scale

    NARCIS (Netherlands)

    Lehmann, N.; Finger, R.; Klein, T.; Calanca, P.; Walter, A.

    2013-01-01

    Climate change will alter the environmental conditions for crop growth and require adjustments in management practices at the field scale. In this paper, we analyzed the impacts of two different climate change scenarios on optimal field management practices in winterwheat and grain maize production

  5. Single-piece maintenance procedures for the TITAN reversed-field pinch reactor

    International Nuclear Information System (INIS)

    Grotz, S.P.; Creedon, R.L.; Cooke, P.I.H.; Duggan, W.P.; Krakowski, R.A.; Najmabadi, F.; Wong, C.P.C.

    1987-01-01

    The TITAN reactor is a compact (major radius of 3.9 m and minor plasma radius of 0.6 m), high neutron wall loading (--18MW/m 2 ) fusion energy system based on the reversed-field pinch (RFP) concept. The TITAN-I fusion power core (FPC) is a lithium, self-cooled design with vanadium alloy (V-3Ti-1Si) structural material. The compact design of the TITAN fusion power core (FPC) reduces the system to a few small and relatively low mass components, making toroidal segmentation of the FPC unnecessary. A single-piece maintenance procedure in which the replaceable first wall and blanket is removed as a single unit is, therefore, possible. The TITAN FPC design provides for top access to the reactor with vertical lifts used to remove the components. The number of remote handling procedures is few and the movements are uncomplicated. The annual torus replacement requires that the reusable ohmic-heating coil set and hot-shield assembly be removed and temporarily stored in a hot cell. The used first wall and blanket assembly is drained and disconnected from the coolant supply system, then lifted to a processing room where it is cooled and prepared for Class-C waste burial. The new, pre-tested first wall and blanket assembly is then lowered into position and the removal procedure is reversed to complete the replacement process

  6. Optimization of the procedure for the synthesis of calcium lactate pentahydrate in laboratory and semi-industrial conditions

    Directory of Open Access Journals (Sweden)

    Ušćumlić Gordana S.

    2009-01-01

    Full Text Available This paper is concerned on the development of the optimal laboratory procedure for the synthesis of calcium lactate pentahydrate and the application of obtained results in a project for a semi-industrial installation for its production. Calcium lactate is used as an additive in numerous food and pharmaceutical products. Basically, it has to satisfy quality requirements. That was the reason why the procedure for its synthesis had to be optimized in aspects of selection of reactants, their molar ratio, necessary laboratory equipment, reactant addition order, working temperature, isolation of final product from the reaction mixture, yield and product quality. A semi-industrial installation for the production of calcium lactate pentahydrate is projected on the basis of the results of this investigation. The importance of this investigation arises from the fact that this salt is not produced in Serbia and the complete quantity (about 20 t per year is imported.

  7. Optimization of Transverse Oscillating Fields for Vector Velocity Estimation with Convex Arrays

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt

    2013-01-01

    A method for making Vector Flow Images using the transverse oscillation (TO) approach on a convex array is presented. The paper presents optimization schemes for TO fields for convex probes and evaluates their performance using Field II simulations and measurements using the SARUS experimental...... from 90 to 45 degrees in steps of 15 degrees. The optimization routine changes the lateral oscillation period lx to yield the best possible estimates based on the energy ratio between positive and negative spatial frequencies in the ultrasound field. The basic equation for lx gives 1.14 mm at 40 mm...

  8. Measurement procedure to assess exposure to extremely low-frequency fields: A primary school case study

    International Nuclear Information System (INIS)

    Alonso, A.; Bahillo, A.; De la Rosa, R.; Carrera, A.; Duran, R. J.; Fernandez, P.

    2012-01-01

    How to correctly measure the exposure of general public to extremely low-frequency (ELF) radiation is a key issue for ELF epidemiological studies. This paper proposes a measurement procedure to accurately assess the exposure of people to electric and magnetic field in the frequency band from 5 Hz to 100 kHz in buildings and their premises. As ELF radiation could be particularly harmful to children, the measurement procedure is focused on exposure to ELF in schools. Thus, the students' exposure to ELF fields can be assessed by correlating the ELF measurements to the hours of school activity. In this paper, the measurement protocol was applied to study the ELF exposure on students from Garcia Quintana primary school in Valladolid, Spain. The campaign of measurements for ELF exposure assessment in this primary school was of great interest for the Regional Council of Public Health because of the social alarm generated by the presence of a significant number cancer cases in children. (authors)

  9. A procedure for temperature-stress fields calculation of WWER-1000 primary circuit in PTS event

    Energy Technology Data Exchange (ETDEWEB)

    Petkov, G [Technical Univ., Dept. Thermal and Nuclear Power Engineering, Sofia (Bulgaria); Groudev, P; Argirov, J [Bulgarian Academy of Science, Inst. for Nuclear Research and Nuclear Energy, Sofia (Bulgaria)

    1997-09-01

    The paper presents the procedure of an investigation of WWER-1000 primary circuit temperature-stress field by the use of thermohydraulic computation data for a pressurized thermal shock event ``Core overcooling``. The procedure is based on a model of the plane stress state with ideal contact between wall and medium for the calculation. The computation data are calculated on the base of WWER-1000 thermohydraulic model by the RELAP5/MOD3 codes. This model was developed jointly by the Bulgarian and BNL/USA staff to provide an analytical tool for performing safety analysis. As a result of calculations by codes the computation data for temperature field law (linear laws of a few distinguished parts) and pressure of coolant at points on inner surface of WWER-1000 primary circuit equipment are received. Such calculations can be used as a base for determination of all-important load-carrying sections of the primary circuit pipes and vessels, which need further consideration. (author). 7 refs, 2 figs, 2 tabs.

  10. Optimization of Pockels electric field in transverse modulated optical voltage sensor

    Science.gov (United States)

    Huang, Yifan; Xu, Qifeng; Chen, Kun-Long; Zhou, Jie

    2018-05-01

    This paper investigates the possibilities of optimizing the Pockels electric field in a transverse modulated optical voltage sensor with a spherical electrode structure. The simulations show that due to the edge effect and the electric field concentrations and distortions, the electric field distributions in the crystal are non-uniform. In this case, a tiny variation in the light path leads to an integral error of more than 0.5%. Moreover, a 2D model cannot effectively represent the edge effect, so a 3D model is employed to optimize the electric field distributions. Furthermore, a new method to attach a quartz crystal to the electro-optic crystal along the electric field direction is proposed to improve the non-uniformity of the electric field. The integral error is reduced therefore from 0.5% to 0.015% and less. The proposed method is simple, practical and effective, and it has been validated by numerical simulations and experimental tests.

  11. Exploring channeling optimized radiofrequency energy: a review of radiofrequency history and applications in esthetic fields.

    Science.gov (United States)

    Belenky, Inna; Margulis, Ariel; Elman, Monica; Bar-Yosef, Udi; Paun, Silviu D

    2012-03-01

    Because of its high efficiency and safety, radiofrequency (RF) energy is widely used in the dermatological field for heating biological tissue in various esthetic applications, including skin tightening, skin lifting, body contouring, and cellulite reduction. This paper reviews the literature on the use of nonablative RF energy in the esthetic field and its scientific background. The purpose of this article is to describe in detail the extensive use of medical devices based on RF technology, the development of these medical devices over the years, and recent developments and trends in RF technology. The authors conducted a systematic search of publications that address safety and efficacy issues, technical system specifications, and clinical techniques. Finally, the authors focused on their own clinical experiences with the use of patented Channeling Optimized RF Energy technique and mechanical massage. An in-vivo study was conducted in domestic pigs, with a thermal video camera. Twenty-seven female patients participated in a cellulite and body shaping study. The treatments were conducted according to a three-phase protocol. An additional 16 females participated in a skin tightening case study. All of the patients underwent three treatment sessions at 3-week intervals, each according to a protocol specific to the area being treated. The review of the literature on RF-based systems revealed that these systems are safe, with low risks for potential side effects, and effective for cellulite, body contouring, and skin tightening procedures. The in-vivo measurements confirmed the theory that the penetration depth of RF is an inverse function of its frequency, and using a vacuum mechanism makes an additional contribution to the RF energy penetration. The heating effect of RF was also found to increase blood circulation and to induce collagen remodeling. The results from the cellulite and body shaping treatments showed an overall average improvement of 55% in the

  12. A TOTP-Based Enhanced Route Optimization Procedure for Mobile IPv6 to Reduce Handover Delay and Signalling Overhead

    Science.gov (United States)

    Shah, Peer Azmat; Hasbullah, Halabi B.; Lawal, Ibrahim A.; Aminu Mu'azu, Abubakar; Tang Jung, Low

    2014-01-01

    Due to the proliferation of handheld mobile devices, multimedia applications like Voice over IP (VoIP), video conferencing, network music, and online gaming are gaining popularity in recent years. These applications are well known to be delay sensitive and resource demanding. The mobility of mobile devices, running these applications, across different networks causes delay and service disruption. Mobile IPv6 was proposed to provide mobility support to IPv6-based mobile nodes for continuous communication when they roam across different networks. However, the Route Optimization procedure in Mobile IPv6 involves the verification of mobile node's reachability at the home address and at the care-of address (home test and care-of test) that results in higher handover delays and signalling overhead. This paper presents an enhanced procedure, time-based one-time password Route Optimization (TOTP-RO), for Mobile IPv6 Route Optimization that uses the concepts of shared secret Token, time based one-time password (TOTP) along with verification of the mobile node via direct communication and maintaining the status of correspondent node's compatibility. The TOTP-RO was implemented in network simulator (NS-2) and an analytical analysis was also made. Analysis showed that TOTP-RO has lower handover delays, packet loss, and signalling overhead with an increased level of security as compared to the standard Mobile IPv6's Return-Routability-based Route Optimization (RR-RO). PMID:24688398

  13. Optimization in the utility maximization framework for conservation planning: a comparison of solution procedures in a study of multifunctional agriculture

    Science.gov (United States)

    Kreitler, Jason R.; Stoms, David M.; Davis, Frank W.

    2014-01-01

    Quantitative methods of spatial conservation prioritization have traditionally been applied to issues in conservation biology and reserve design, though their use in other types of natural resource management is growing. The utility maximization problem is one form of a covering problem where multiple criteria can represent the expected social benefits of conservation action. This approach allows flexibility with a problem formulation that is more general than typical reserve design problems, though the solution methods are very similar. However, few studies have addressed optimization in utility maximization problems for conservation planning, and the effect of solution procedure is largely unquantified. Therefore, this study mapped five criteria describing elements of multifunctional agriculture to determine a hypothetical conservation resource allocation plan for agricultural land conservation in the Central Valley of CA, USA. We compared solution procedures within the utility maximization framework to determine the difference between an open source integer programming approach and a greedy heuristic, and find gains from optimization of up to 12%. We also model land availability for conservation action as a stochastic process and determine the decline in total utility compared to the globally optimal set using both solution algorithms. Our results are comparable to other studies illustrating the benefits of optimization for different conservation planning problems, and highlight the importance of maximizing the effectiveness of limited funding for conservation and natural resource management.

  14. A TOTP-Based Enhanced Route Optimization Procedure for Mobile IPv6 to Reduce Handover Delay and Signalling Overhead

    Directory of Open Access Journals (Sweden)

    Peer Azmat Shah

    2014-01-01

    Full Text Available Due to the proliferation of handheld mobile devices, multimedia applications like Voice over IP (VoIP, video conferencing, network music, and online gaming are gaining popularity in recent years. These applications are well known to be delay sensitive and resource demanding. The mobility of mobile devices, running these applications, across different networks causes delay and service disruption. Mobile IPv6 was proposed to provide mobility support to IPv6-based mobile nodes for continuous communication when they roam across different networks. However, the Route Optimization procedure in Mobile IPv6 involves the verification of mobile node’s reachability at the home address and at the care-of address (home test and care-of test that results in higher handover delays and signalling overhead. This paper presents an enhanced procedure, time-based one-time password Route Optimization (TOTP-RO, for Mobile IPv6 Route Optimization that uses the concepts of shared secret Token, time based one-time password (TOTP along with verification of the mobile node via direct communication and maintaining the status of correspondent node’s compatibility. The TOTP-RO was implemented in network simulator (NS-2 and an analytical analysis was also made. Analysis showed that TOTP-RO has lower handover delays, packet loss, and signalling overhead with an increased level of security as compared to the standard Mobile IPv6’s Return-Routability-based Route Optimization (RR-RO.

  15. A TOTP-based enhanced route optimization procedure for mobile IPv6 to reduce handover delay and signalling overhead.

    Science.gov (United States)

    Shah, Peer Azmat; Hasbullah, Halabi B; Lawal, Ibrahim A; Aminu Mu'azu, Abubakar; Tang Jung, Low

    2014-01-01

    Due to the proliferation of handheld mobile devices, multimedia applications like Voice over IP (VoIP), video conferencing, network music, and online gaming are gaining popularity in recent years. These applications are well known to be delay sensitive and resource demanding. The mobility of mobile devices, running these applications, across different networks causes delay and service disruption. Mobile IPv6 was proposed to provide mobility support to IPv6-based mobile nodes for continuous communication when they roam across different networks. However, the Route Optimization procedure in Mobile IPv6 involves the verification of mobile node's reachability at the home address and at the care-of address (home test and care-of test) that results in higher handover delays and signalling overhead. This paper presents an enhanced procedure, time-based one-time password Route Optimization (TOTP-RO), for Mobile IPv6 Route Optimization that uses the concepts of shared secret Token, time based one-time password (TOTP) along with verification of the mobile node via direct communication and maintaining the status of correspondent node's compatibility. The TOTP-RO was implemented in network simulator (NS-2) and an analytical analysis was also made. Analysis showed that TOTP-RO has lower handover delays, packet loss, and signalling overhead with an increased level of security as compared to the standard Mobile IPv6's Return-Routability-based Route Optimization (RR-RO).

  16. Optimizing Travel Time to Outpatient Interventional Radiology Procedures in a Multi-Site Hospital System Using a Google Maps Application.

    Science.gov (United States)

    Mandel, Jacob E; Morel-Ovalle, Louis; Boas, Franz E; Ziv, Etay; Yarmohammadi, Hooman; Deipolyi, Amy; Mohabir, Heeralall R; Erinjeri, Joseph P

    2018-02-20

    The purpose of this study is to determine whether a custom Google Maps application can optimize site selection when scheduling outpatient interventional radiology (IR) procedures within a multi-site hospital system. The Google Maps for Business Application Programming Interface (API) was used to develop an internal web application that uses real-time traffic data to determine estimated travel time (ETT; minutes) and estimated travel distance (ETD; miles) from a patient's home to each a nearby IR facility in our hospital system. Hypothetical patient home addresses based on the 33 cities comprising our institution's catchment area were used to determine the optimal IR site for hypothetical patients traveling from each city based on real-time traffic conditions. For 10/33 (30%) cities, there was discordance between the optimal IR site based on ETT and the optimal IR site based on ETD at non-rush hour time or rush hour time. By choosing to travel to an IR site based on ETT rather than ETD, patients from discordant cities were predicted to save an average of 7.29 min during non-rush hour (p = 0.03), and 28.80 min during rush hour (p travel time when more than one location providing IR procedures is available within the same hospital system.

  17. Optimal training design for procedural motor skills: a review and application to laparoscopic surgery

    NARCIS (Netherlands)

    Spruit, E.N.; Band, G.P.H.; Hamming, J.F.; Ridderinkhof, K.R.

    2014-01-01

    This literature review covers the choices to consider in training complex procedural, perceptual and motor skills. In particular, we focus on laparoscopic surgery. An overview is provided of important training factors modulating the acquisition, durability, transfer, and efficiency of trained

  18. Investigation on a procedure for optimal axial depth of cut accuracy in micromilling

    DEFF Research Database (Denmark)

    Bissacco, Giuliano; Hansen, Hans Nørgaard; De Chiffre, Leonardo

    2005-01-01

    On the basis of a previously developed procedure for control of axial depth of cut in high accuracy micromilling operations, this paper presents an investigation on the estimation of the uncertainty of the set axial depth of cut.......On the basis of a previously developed procedure for control of axial depth of cut in high accuracy micromilling operations, this paper presents an investigation on the estimation of the uncertainty of the set axial depth of cut....

  19. Topology Optimization of a High-Temperature Superconducting Field Winding of a Synchronous Machine

    DEFF Research Database (Denmark)

    Pozzi, Matias; Mijatovic, Nenad; Jensen, Bogi Bech

    2013-01-01

    This paper presents topology optimization (TO) of the high-temperature superconductor (HTS) field winding of an HTS synchronous machine. The TO problem is defined in order to find the minimum HTS material usage for a given HTS synchronous machine design. Optimization is performed using a modified...... genetic algorithm with local optimization search based on on/off sensitivity analysis. The results show an optimal HTS coil distribution, achieving compact designs with a maximum of approximately 22% of the available space for the field winding occupied with HTS tape. In addition, this paper describes...... potential HTS savings, which could be achieved using multiple power supplies for the excitation of the machine. Using the TO approach combined with two excitation currents, an additional HTS saving of 9.1% can be achieved....

  20. Bias Magnetic Field of Stack Giant Magnetostrictive Actuator: Design, Analysis, and Optimization

    Directory of Open Access Journals (Sweden)

    Zhaoshu Yang

    2016-01-01

    Full Text Available Many novel applications using giant magnetostrictive actuators (GMA require their actuators output bidirectional strokes to be large enough to drive the load. In these cases, the sophisticated method to form such a sufficient bias field with minimum power and bulk consumption should be considered in the principal stage of GMA design. This paper concerns the methodology of bias field design for a specific GMA with stack PMs and GMMs (SGMA: both loop and field models for its bias field are established; the optimization method for given SGMA structure is outlined; a prototype is fabricated to verify the theory. Simulation and test results indicate that the bias field could be exerted more easily using SGMA structure; the modeling and optimization methodology for SGMA is valid in practical design.

  1. Technical procedures for implementation of aesthetics site studies, Deaf Smith County site, Texas: Environmental Field Program

    International Nuclear Information System (INIS)

    1987-06-01

    This chapter introduces the purpose and scope of the visually affected areas determination, as well as definitions, interfaces, and concurrent data needs. This procedure provides a method for determining the extent of visibility of the project. This area is identified as the visually affected area, and becomes the area within which all visual analysis is conducted. The visually affected area analysis of the Deaf Smith County site will involve identifying and mapping the visibility of all major proposed project features. Baseline analysis will be conducted within the overall visually affected area; impact assessment will be conducted within the visually affected area of each major project feature. This procedure presents the guidelines for determining the visually affected area will be in computer data base construction; viewshed modeling, and site visit and verification of results. Computer data base construction will involve digitizing topographic and project facility data from available data source. The extent of the visible area from each major project feature will then be plotted. Finally, these computer-generated visibility plots will be verified in the field

  2. Maintenance procedures for the TITAN-I and TITAN-II reversed field pinch reactors

    International Nuclear Information System (INIS)

    Grotz, S.P.; Duggan, W.; Krakowski, R.; Najmabadi, F.; Wong, C.P.C.

    1989-01-01

    The TITAN reactor is a compact, high-power-density (neutron wall loading 18 MW/m 2 ) machine, based on the reversed-field-pinch (RFP) confinement concept. Two designs for the fusion power core have been examined: TITAN-I is based on a self-cooled lithium loop with a vanadium-alloy structure for the first wall, blanket and shield; and TITAN-II is based on an aqueous loop-in-pool design with a LiNO 3 solution as the coolant and breeder. The compact design of the TITAN fusion power core, (FPC) reduces the system to a few small and relatively low mass components, making toroidal segmentation of the FPC unnecessary. A single-piece maintenance procedure is possible. The potential advantages of single-piece maintenance procedures are: (1) Short period of down time; (2) improved reliability; (3) no adverse effects resulting from unequal levels of irradiation; and (4) ability to continually modify the FPC design. Increased availability can be expected from a fully pre-tested, single-piece FPC. Pre-testing of the FPC throughout the assembly process and prior to installation into the reactor vault is discussed. (orig.)

  3. Low NOx combustion and SCR flow field optimization in a low volatile coal fired boiler.

    Science.gov (United States)

    Liu, Xing; Tan, Houzhang; Wang, Yibin; Yang, Fuxin; Mikulčić, Hrvoje; Vujanović, Milan; Duić, Neven

    2018-08-15

    Low NO x burner redesign and deep air staging have been carried out to optimize the poor ignition and reduce the NO x emissions in a low volatile coal fired 330 MW e boiler. Residual swirling flow in the tangentially-fired furnace caused flue gas velocity deviations at furnace exit, leading to flow field unevenness in the SCR (selective catalytic reduction) system and poor denitrification efficiency. Numerical simulations on the velocity field in the SCR system were carried out to determine the optimal flow deflector arrangement to improve flow field uniformity of SCR system. Full-scale experiment was performed to investigate the effect of low NO x combustion and SCR flow field optimization. Compared with the results before the optimization, the NO x emissions at furnace exit decreased from 550 to 650 mg/Nm³ to 330-430 mg/Nm³. The sample standard deviation of the NO x emissions at the outlet section of SCR decreased from 34.8 mg/Nm³ to 7.8 mg/Nm³. The consumption of liquid ammonia reduced from 150 to 200 kg/h to 100-150 kg/h after optimization. Copyright © 2018. Published by Elsevier Ltd.

  4. Optimal Weighting of Multi-Spacecraft Data to Estimate Gradients of Physical Fields

    Science.gov (United States)

    Chanteur, G. M.; Le Contel, O.; Sahraoui, F.; Retino, A.; Mirioni, L.

    2016-12-01

    Multi-spacecraft missions like the ESA mission CLUSTER and the NASA mission MMS are essential to improve our understanding of physical processes in space plasmas. Several methods were designed in the 90's during the preparation phase of the CLUSTER mission to estimate gradients of physical fields from simultaneous multi-points measurements [1, 2]. Both CLUSTER and MMS involve four spacecraft with identical full scientific payloads including various sensors of electromagnetic fields and different type of particle detectors. In the standard methods described in [1, 2], which are presently in use, data from the four spacecraft have identical weights and the estimated gradients are most reliable when the tetrahedron formed by the four spacecraft is regular. There are three types of errors affecting the estimated gradients (see chapter 14 in [1]) : i) truncature errors are due to local non-linearity of spatial variations, ii) physical errors are due to instruments, and iii) geometrical errors are due to uncertainties on the positions of the spacecraft. An assessment of truncature errors for a given observation requires a theoretical model of the measured field. Instrumental errors can easily be taken into account for a given geometry of the cluster but are usually less than the geometrical errors which diverge quite fast when the tetrahedron flattens, a circumstance occurring twice per orbit of the cluster. Hence reliable gradients can be estimated only on part of the orbit. Reciprocal vectors of the tetrahedron were presented in chapter 4 of [1], they have the advantage over other methods to treat the four spacecraft symmetrically and to allow a theoretical analysis of the errors (see chapters 4 of [1] and 4 of [2]). We will present Generalized Reciprocal Vectors for weighted data and an optimization procedure to improve the reliability of the estimated gradients when the tetrahedron is not regular. A brief example using CLUSTER or MMS data will be given. This approach

  5. Autogenous bone grafts in the esthetic zone: optimizing the procedure using piezosurgery.

    Science.gov (United States)

    Majewski, Piotr

    2012-12-01

    Soft and hard tissue defects pose a therapeutic challenge in modern implant dentistry. There are a multitude of surgical techniques available, and it is necessary to match the problem with the solution. This report describes the reconstruction of the alveolar ridge in the esthetic zone with the help of autogenous bone blocks harvested from the chin that were shaped to fit and stabilized at the recipient site. The procedures were performed using Piezosurgery, which made it possible to introduce surgical modifications and had a significant impact on the accuracy of the procedure. An observation period of 2 to 7 years showed positive stable results for treatment in terms of function and esthetics.

  6. Supersonic acoustic intensity with statistically optimized near-field acoustic holography

    DEFF Research Database (Denmark)

    Fernandez Grande, Efren; Jacobsen, Finn

    2011-01-01

    The concept of supersonic acoustic intensity was introduced some years ago for estimating the fraction of the flow of energy radiated by a source that propagates to the far field. It differs from the usual (active) intensity by excluding the near-field energy resulting from evanescent waves...... to the information provided by the near-field acoustic holography technique. This study proposes a version of the supersonic acoustic intensity applied to statistically optimized near-field acoustic holography (SONAH). The theory, numerical results and an experimental study are presented. The possibility of using...

  7. Optimal Value of Series Capacitors for Uniform Field Distribution in Transmission Line MRI Coils

    DEFF Research Database (Denmark)

    Zhurbenko, Vitaliy

    2016-01-01

    Transmission lines are often used as coils in high field magnetic resonance imaging (MRI). Due to the distributed nature of transmission lines, coils based on them produce inhomogeneous field. This work investigates application of series capacitors to improve field homogeneity along the coil....... The equations for optimal values of evenly distributed capacitors are derived and expressed in terms of the implemented transmission line parameters.The achieved magnetic field homogeneity is estimated under quasistatic approximation and compared to the regular transmission line resonator. Finally, a more...... practical case of a microstrip line coil with two series capacitors is considered....

  8. Decision theoretical justification of optimization criteria for near-real-time accountancy procedures

    International Nuclear Information System (INIS)

    Avenhaus, R.

    1992-01-01

    In the beginning of nuclear material safeguards, emphasis was placed on safe detection of diversion of nuclear material. Later, the aspect of timely detection became equally important. Since there is a trade-off between these two objectives, the question of an appropriate compromise was raised. In this paper, a decision theoretical framework is presented in which the objectives of the two players, inspector and inspectee, are expressed in terms of general utility functions. Within this framework, optimal safeguards strategies are defined, and furthermore, conditions are formulated under which the optimization criteria corresponding to the objectives mentioned above can be justified

  9. An optimized intermolecular force field for hydrogen-bonded organic molecular crystals using atomic multipole electrostatics

    International Nuclear Information System (INIS)

    Pyzer-Knapp, Edward O.; Thompson, Hugh P. G.; Day, Graeme M.

    2016-01-01

    An empirically parameterized intermolecular force field is developed for crystal structure modelling and prediction. The model is optimized for use with an atomic multipole description of electrostatic interactions. We present a re-parameterization of a popular intermolecular force field for describing intermolecular interactions in the organic solid state. Specifically we optimize the performance of the exp-6 force field when used in conjunction with atomic multipole electrostatics. We also parameterize force fields that are optimized for use with multipoles derived from polarized molecular electron densities, to account for induction effects in molecular crystals. Parameterization is performed against a set of 186 experimentally determined, low-temperature crystal structures and 53 measured sublimation enthalpies of hydrogen-bonding organic molecules. The resulting force fields are tested on a validation set of 129 crystal structures and show improved reproduction of the structures and lattice energies of a range of organic molecular crystals compared with the original force field with atomic partial charge electrostatics. Unit-cell dimensions of the validation set are typically reproduced to within 3% with the re-parameterized force fields. Lattice energies, which were all included during parameterization, are systematically underestimated when compared with measured sublimation enthalpies, with mean absolute errors of between 7.4 and 9.0%

  10. Developing Optimal Procedure of Emergency Outside Cooling Water Injection for APR1400 Extended SBO Scenario Using MARS Code

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Jong Rok; Oh, Seung Jong [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2013-10-15

    In this study, we examined optimum operator actions to mitigate extended SBO using MARS code. Particularly, this paper focuses on analyzing outside core cooling water injection scenario, and aimed to develop optimal extended SBO procedure. Supplying outside emergency cooling water is the key feature of flexible strategy in extended SBO situation. An optimum strategy to maintain core cooling is developed for typical extended SBO. MARS APR1400 best estimate model was used to find optimal procedure. Also RCP seal leakage effect was considered importantly. Recent Fukushima accident shows the importance of mitigation capability against extended SBO scenarios. In Korea, all nuclear power plants incorporated various measures against Fukushima-like events. For APR1400 NPP, outside connectors are installed to inject cooling water using fire trucks or portable pumps. Using these connectors, outside cooling water can be provided to reactor, steam generators (SG), containment spray system, and spent fuel pool. In U. S., similar approach is chosen to provide a diverse and flexible means to prevent fuel damage (core and SFP) in external event conditions resulting in extended loss of AC power and loss of ultimate heat sink. Hence, hardware necessary to cope with extended SBO is already available for APR1400. However, considering the complex and stressful condition encountered by operators during extended SBO, it is important to develop guidelines/procedures to best cope with the event.

  11. A novel design procedure for tractor clutch fingers by using optimization and response surface methods

    Energy Technology Data Exchange (ETDEWEB)

    Dogan, Oguz; Karpat, Fatih; Yuce, Celalettin; Kaya, Necmettin; Yavuz, Nurettin [Uludag University, Gorukle (Turkmenistan); Sen, Hasan [Valeo A. S., Bursa (Turkmenistan)

    2016-06-15

    This paper presents a methodology for re-designing a failed tractor transmission component subjected to cyclic loading. Unlike other vehicles, tractors cope with tough working conditions. Thus, it is necessary to re-design components by using modern optimization techniques. To extend their service life, we present a design methodology for a failed tractor clutch power take-off finger. The finger was completely re-designed using topology and shape optimization approach. Stress-life based fatigue analyses were performed. Shape optimization and response surface methodology were conducted to obtain optimum dimensions of the finger. Two design parameters were selected for the design of experiment method and 15 cases were analyzed. By using design of the experiment method, three responses were obtained: Maximum stresses, mass, and displacement depending on the selected the design parameters. After solving the optimization problem, we achieved a maximum stress and mass reduction of 14% and 6%, respectively. The stiffness was improved up to 31.6% compared to the initial design.

  12. Optimization of dyeing wool fibers procedure with Isatis tinctoria by Response Surface Methodology

    NARCIS (Netherlands)

    Barani, H.; Nasiriboroumand, Majid; Haji, A.; Kazemipour, M.

    2012-01-01

    The response surface method (RMS) was used to optimize the color strength (K/S) of the wool fibers dyed with Isatis tinctoria. The eight independent variable terms, in which two of them are categorical and the other six numerical, were selected at two levels (low and high). The ANOVA test results of

  13. Computational procedure of optimal inventory model involving controllable backorder rate and variable lead time with defective units

    Science.gov (United States)

    Lee, Wen-Chuan; Wu, Jong-Wuu; Tsou, Hsin-Hui; Lei, Chia-Ling

    2012-10-01

    This article considers that the number of defective units in an arrival order is a binominal random variable. We derive a modified mixture inventory model with backorders and lost sales, in which the order quantity and lead time are decision variables. In our studies, we also assume that the backorder rate is dependent on the length of lead time through the amount of shortages and let the backorder rate be a control variable. In addition, we assume that the lead time demand follows a mixture of normal distributions, and then relax the assumption about the form of the mixture of distribution functions of the lead time demand and apply the minimax distribution free procedure to solve the problem. Furthermore, we develop an algorithm procedure to obtain the optimal ordering strategy for each case. Finally, three numerical examples are also given to illustrate the results.

  14. Structural optimization procedure of a composite wind turbine blade for reducing both material cost and blade weight

    Science.gov (United States)

    Hu, Weifei; Park, Dohyun; Choi, DongHoon

    2013-12-01

    A composite blade structure for a 2 MW horizontal axis wind turbine is optimally designed. Design requirements are simultaneously minimizing material cost and blade weight while satisfying the constraints on stress ratio, tip deflection, fatigue life and laminate layup requirements. The stress ratio and tip deflection under extreme gust loads and the fatigue life under a stochastic normal wind load are evaluated. A blade element wind load model is proposed to explain the wind pressure difference due to blade height change during rotor rotation. For fatigue life evaluation, the stress result of an implicit nonlinear dynamic analysis under a time-varying fluctuating wind is converted to the histograms of mean and amplitude of maximum stress ratio using the rainflow counting algorithm Miner's rule is employed to predict the fatigue life. After integrating and automating the whole analysis procedure an evolutionary algorithm is used to solve the discrete optimization problem.

  15. Optimization of Saturn paraboloid magnetospheric field model parameters using Cassini equatorial magnetic field data

    Directory of Open Access Journals (Sweden)

    E. S. Belenkaya

    2016-07-01

    Full Text Available The paraboloid model of Saturn's magnetosphere describes the magnetic field as being due to the sum of contributions from the internal field of the planet, the ring current, and the tail current, all contained by surface currents inside a magnetopause boundary which is taken to be a paraboloid of revolution about the planet-Sun line. The parameters of the model have previously been determined by comparison with data from a few passes through Saturn's magnetosphere in compressed and expanded states, depending on the prevailing dynamic pressure of the solar wind. Here we significantly expand such comparisons through examination of Cassini magnetic field data from 18 near-equatorial passes that span wide ranges of local time, focusing on modelling the co-latitudinal field component that defines the magnetic flux passing through the equatorial plane. For 12 of these passes, spanning pre-dawn, via noon, to post-midnight, the spacecraft crossed the magnetopause during the pass, thus allowing an estimate of the concurrent subsolar radial distance of the magnetopause R1 to be made, considered to be the primary parameter defining the scale size of the system. The best-fit model parameters from these passes are then employed to determine how the parameters vary with R1, using least-squares linear fits, thus providing predictive model parameters for any value of R1 within the range. We show that the fits obtained using the linear approximation parameters are of the same order as those for the individually selected parameters. We also show that the magnetic flux mapping to the tail lobes in these models is generally in good accord with observations of the location of the open-closed field line boundary in Saturn's ionosphere, and the related position of the auroral oval. We then investigate the field data on six passes through the nightside magnetosphere, for which the spacecraft did not cross the magnetopause, such that in this case we compare the

  16. A network society communicative model for optimizing the Refugee Status Determination (RSD procedures

    Directory of Open Access Journals (Sweden)

    Andrea Pacheco Pacífico

    2013-01-01

    Full Text Available This article recommends a new way to improve Refugee Status Determination (RSD procedures by proposing a network society communicative model based on active involvement and dialogue among all implementing partners. This model, named after proposals from Castells, Habermas, Apel, Chimni, and Betts, would be mediated by the United Nations High Commissioner for Refugees (UNHCR, whose role would be modeled after that of the International Committee of the Red Cross (ICRC practice.

  17. Optimization of patient protection using rare earth screen in conventional imaging procedure

    International Nuclear Information System (INIS)

    Inkoom, S.; Schandorf, C.; Fletcher, J.J.

    2008-01-01

    The purpose of this study was to optimize patient protection using rare earth screen of speed 400 in place of conventional screen-film of speed 200. The entrance surface dose (ESD) for the two screen-film systems was determined for patients undergoing simple radiographic examinations (chest, lumbar spine and pelvis series). The determination of the ESD included backscatter factors. The ESD was the optimizing parameter and its trade off with the image quality assessment, which was surveyed based on the information obtained through standardized questionnaire. The estimated ESDs were compared with reference levels set by the Community of European Commission (CEC) for a standard adult patient. For chest PA, ESD estimates were lower than the CEC reference levels whilst that of lumbar spine AP and LAT and pelvis AP were high. Upon the adoption of rare earth screen of speed 400, a dose reduction of 33% for chest, 17% for lumbar spine and 28% for pelvis examinations was achieved. From the observations made from this study, some corrective actions such as equipment quality control of parameters that affect patient dose and image quality like kVp accuracy and consistency, mAs accuracy and consistency, optimal film processing conditions, regular film reject analysis to detect and minimize the root causes and contributory factors to poor image quality and periodic training of staff on dose reduction techniques must be undertaken. Regular assessment of patient dose and image quality, equipment quality control, adoption of faster rare earth screens and optimum radiographic technique are therefore recommended in order to achieve optimization goals. (author)

  18. Clay modified crushed salt for shaft sealing elements. Material optimization and evaluation in field tests

    Energy Technology Data Exchange (ETDEWEB)

    Glaubach, Uwe; Hofmann, Martin; Gruner, Matthias; Kudla, Wolfram [TU Bergakademie Freiberg (Germany). Inst. of Mining and Special Civil Engineering

    2015-07-01

    Salt-based materials are intended to use for backfill and sealing systems in geotechnical barriers in underground HLW-repositories. Due to the creep of the saliniferous host rock, the salt backfill will be compacted during several hundreds or thousands years of operation to a minimum of porosity resp. permeability. To raise the sealing potential of a salt-based backfill, the porosity after construction should be minimized by optimal material performance and compaction performance. A procedure to optimize the grain size distribution of crushed salt and its water and clay content is described. The optimized salt fraction gets a better compaction behavior than straight mine-run salt. The addition of a filler-like material (e.g. Friedland Clay Powder) reduces the total porosity and permeability. Backfill columns made from crushed salt and clay probably include an instant sealing function.

  19. Optimization of the GBMV2 implicit solvent force field for accurate simulation of protein conformational equilibria.

    Science.gov (United States)

    Lee, Kuo Hao; Chen, Jianhan

    2017-06-15

    Accurate treatment of solvent environment is critical for reliable simulations of protein conformational equilibria. Implicit treatment of solvation, such as using the generalized Born (GB) class of models arguably provides an optimal balance between computational efficiency and physical accuracy. Yet, GB models are frequently plagued by a tendency to generate overly compact structures. The physical origins of this drawback are relatively well understood, and the key to a balanced implicit solvent protein force field is careful optimization of physical parameters to achieve a sufficient level of cancellation of errors. The latter has been hampered by the difficulty of generating converged conformational ensembles of non-trivial model proteins using the popular replica exchange sampling technique. Here, we leverage improved sampling efficiency of a newly developed multi-scale enhanced sampling technique to re-optimize the generalized-Born with molecular volume (GBMV2) implicit solvent model with the CHARMM36 protein force field. Recursive optimization of key GBMV2 parameters (such as input radii) and protein torsion profiles (via the CMAP torsion cross terms) has led to a more balanced GBMV2 protein force field that recapitulates the structures and stabilities of both helical and β-hairpin model peptides. Importantly, this force field appears to be free of the over-compaction bias, and can generate structural ensembles of several intrinsically disordered proteins of various lengths that seem highly consistent with available experimental data. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  20. Optimal usage of computing grid network in the fields of nuclear fusion computing task

    International Nuclear Information System (INIS)

    Tenev, D.

    2006-01-01

    Nowadays the nuclear power becomes the main source of energy. To make its usage more efficient, the scientists created complicated simulation models, which require powerful computers. The grid computing is the answer to powerful and accessible computing resources. The article observes, and estimates the optimal configuration of the grid environment in the fields of the complicated nuclear fusion computing tasks. (author)

  1. Determination of the optimal method for the field-in-field technique in breast tangential radiotherapy

    International Nuclear Information System (INIS)

    Tanaka, Hidekazu; Hayashi, Shinya; Hoshi, Hiroaki

    2014-01-01

    Several studies have reported the usefulness of the field-in-field (FIF) technique in breast radiotherapy. However, the methods for the FIF technique used in these studies vary. These methods were classified into three categories. We simulated a radiotherapy plan with each method and analyzed the outcomes. In the first method, a pair of subfields was added to each main field: the single pair of subfields method (SSM). In the second method, three pairs of subfields were added to each main field: the multiple pairs of subfields method (MSM). In the third method, subfields were alternately added: the alternate subfields method (ASM). A total of 51 patients were enrolled in this study. The maximum dose to the planning target volume (PTV) (Dmax) and the volumes of the PTV receiving 100% of the prescription dose (V100%) were calculated. The thickness of the breast between the chest wall and skin surface was measured, and patients were divided into two groups according to the median. In the overall series, the average V100% with ASM (60.3%) was significantly higher than with SSM (52.6%) and MSM (48.7%). In the thin breast group as well, the average V100% with ASM (57.3%) and SSM (54.2%) was significantly higher than that with MSM (43.3%). In the thick breast group, the average V100% with ASM (63.4%) was significantly higher than that with SSM (51.0%) and MSM (54.4%). ASM resulted in better dose distribution, regardless of the breast size. Moreover, planning for ASM required a relatively short time. ASM was considered the most preferred method. (author)

  2. A novel patch-field design using an optimized grid filter for passively scattered proton beams

    International Nuclear Information System (INIS)

    Li Yupeng; Zhang Xiaodong; Dong Lei; Mohan, Radhe

    2007-01-01

    For tumors with highly complex shapes, a 'patching' strategy is often used in passively scattered proton therapy to match the sharp distal edge of the spread-out Bragg peak (SOBP) of the patch field to the lateral penumbra of the through field at 50% dose level. The differences in the dose gradients at the distal edge and at the lateral penumbra could cause hot and cold doses at the junction. In this note, we describe an algorithm developed to optimize the range compensator design to yield a more uniform dose distribution at the junction. The algorithm is based on the fact that the distal fall-off of the SOBP can be tailored using a grid filter that is placed perpendicular to the beam's path. The filter is optimized so that the distal fall-off of the patch field complements the lateral penumbra fall-off of the through field. In addition to optimizing the fall-off, the optimization process implicitly accounts for the limitations of conventional compensator design algorithms. This algorithm uses simple ray tracing to determine the compensator shape and ignore scatter. The compensated dose distribution may therefore differ substantially from the intended dose distribution, especially when complex heterogeneities are encountered, such as those in the head and neck. In such a case, an adaptive optimization strategy can be used to optimize the 'grid' filter locally considering the tissue heterogeneities. The grid filter thus obtained is superimposed on the original range compensator so that the composite compensator leads to a more uniform dose distribution at the patch junction. An L-shaped head and neck tumor was used to demonstrate the validity of the proposed algorithm. A robustness analysis with focus on range uncertainty effect is carried out. (note)

  3. Topology optimized and 3D printed polymer-bonded permanent magnets for a predefined external field

    Science.gov (United States)

    Huber, C.; Abert, C.; Bruckner, F.; Pfaff, C.; Kriwet, J.; Groenefeld, M.; Teliban, I.; Vogler, C.; Suess, D.

    2017-08-01

    Topology optimization offers great opportunities to design permanent magnetic systems that have specific external field characteristics. Additive manufacturing of polymer-bonded magnets with an end-user 3D printer can be used to manufacture permanent magnets with structures that had been difficult or impossible to manufacture previously. This work combines these two powerful methods to design and manufacture permanent magnetic systems with specific properties. The topology optimization framework is simple, fast, and accurate. It can also be used for the reverse engineering of permanent magnets in order to find the topology from field measurements. Furthermore, a magnetic system that generates a linear external field above the magnet is presented. With a volume constraint, the amount of magnetic material can be minimized without losing performance. Simulations and measurements of the printed systems show very good agreement.

  4. Optimal Magnetic Field Shielding Method by Metallic Sheets in Wireless Power Transfer System

    Directory of Open Access Journals (Sweden)

    Feng Wen

    2016-09-01

    Full Text Available To meet the regulations established to limit human exposure to time-varying electromagnetic fields (EMFs such as the International Committee on Non-Ionizing Radiation Protection (ICNIRP guidelines, thin metallic sheets are often used to shield magnetic field leakage in high power applications of wireless power transfer (WPT systems based on magnetic field coupling. However, the metals in the vicinity of the WPT coils cause the decrease of self and mutual inductances and increase of effective series resistance; as such, the electric performance including transmission power and the efficiency of the system is affected. With the research objective of further investigating excellent shielding effectiveness associated with system performance, the utilization of the optimal magnetic field shielding method by metallic sheets in magnetic field coupling WPT is carried out in this paper. The circuit and 3D Finite Element Analysis (FEA models are combined to predict the magnetic field distribution and electrical performance. Simulation and experiment results show that the method is very effective by obtaining the largest possible coupling coefficient of the WPT coils within the allowable range and then reducing the value nearest to and no smaller than the critical coupling coefficient via geometric unbroken metallic sheets. The optimal magnetic field shielding method which considers the system efficiency, transmission power, transmission distance, and system size is also achieved using the analytic hierarchy process (AHP. The results can benefit WPT by helping to achieve efficient energy transfer and safe use in metal shielded equipment.

  5. Optimized molecular dynamics force fields applied to the helix-coil transition of polypeptides.

    Science.gov (United States)

    Best, Robert B; Hummer, Gerhard

    2009-07-02

    Obtaining the correct balance of secondary structure propensities is a central priority in protein force-field development. Given that current force fields differ significantly in their alpha-helical propensities, a correction to match experimental results would be highly desirable. We have determined simple backbone energy corrections for two force fields to reproduce the fraction of helix measured in short peptides at 300 K. As validation, we show that the optimized force fields produce results in excellent agreement with nuclear magnetic resonance experiments for folded proteins and short peptides not used in the optimization. However, despite the agreement at ambient conditions, the dependence of the helix content on temperature is too weak, a problem shared with other force fields. A fit of the Lifson-Roig helix-coil theory shows that both the enthalpy and entropy of helix formation are too small: the helix extension parameter w agrees well with experiment, but its entropic and enthalpic components are both only about half the respective experimental estimates. Our structural and thermodynamic analyses point toward the physical origins of these shortcomings in current force fields, and suggest ways to address them in future force-field development.

  6. Investigations into the Optimization of Multi-Source Strength Brachytherapy Treatment Procedures

    CERN Document Server

    Henderson, D L; Yoo, S

    2002-01-01

    The goal of this project is to investigate the use of multi-strength and multi-specie radioactive sources in permanent prostate implant brachytherapy. In order to fulfill the requirement for an optimal dose distribution, the prescribed dose should be delivered to the target in a nearly uniform dose distribution while simultaneously sparing sensitive structures. The treatment plan should use a small number of needles and sources while satisfying the treatment requirements. The hypothesis for the use of multi-strength and/or multi-specie sources is that a better treatment plan using fewer sources and needles could be obtained than by treatment plans using single-strength sources could reduce the overall number of sources used for treatment. We employ a recently developed greedy algorithm based on the adjoint concept as the optimization search engine. The algorithm utilizes and ''adjoint ratio'', which provides a means of ranking source positions, as the pseudo-objective function. It ha s been shown that the gre...

  7. New strategy of the optimized nuclear medicine procedures for diagnosis and management of thyroid disorder

    International Nuclear Information System (INIS)

    Megahed, Y.M.; El-Haleg, M.O.; Abdel-Aziz, S.M.; Fahim, F.A.; Mahmoud, A.; Ezz-El-Arab, A.; El-Aassar, S.T.; Youssef, A.

    1991-01-01

    This investigation aims to find the optimal contributary RIA test for the final diagnosis of the thyroid disorder subjects. T 3 , T 4 , and TSH-RIA were performed either as a single or a combined test. However, additional tests such as T 3 -uptake, FTI-calculation, and TRH-test were performed when needed. The second part of this work deals with new TSH-MAIA kit delivered by IAEA in order to evaluate its diagnostic efficiency in comparison with the conventional TSH-RIA kit widely used in the developing countries. The obtained data revealed the following: 1. T 4 -RIA is considered to be the optimal contributary single test in the final diagnosis of all thyroid disorders. 2. T 3 + T 4 is the decisive contributary combined RIA-test in the final diagnosis of all thyroid disorders. 3. S.S. TSH-MAIA is more sensitive, specific, and simple to be performed in comparison with the TSH -RIA. Moreover, considerable minute of TSH could be detected by using S.S. TSH-MAIA which was previously considered undetectable.2 fig.2 tab

  8. Optimization of technological procedure for amygdalin isolation from plum seeds (Pruni domesticae semen)

    Science.gov (United States)

    Savic, Ivan M.; Nikolic, Vesna D.; Savic-Gajic, Ivana M.; Nikolic, Ljubisa B.; Ibric, Svetlana R.; Gajic, Dragoljub G.

    2015-01-01

    The process of amygdalin extraction from plum seeds was optimized using central composite design (CCD) and multilayer perceptron (MLP). The effect of time, ethanol concentration, solid-to-liquid ratio, and temperature on the amygdalin content in the extracts was estimated using both mathematical models. The MLP 4-3-1 with exponential function in hidden layer and linear function in output layer was used for describing the extraction process. MLP model was more superior compared with CCD model due to better prediction ability. According to MLP model, the suggested optimal conditions are: time of 120 min, 100% (v/v) ethanol, solid-to liquid ratio of 1:25 (m/v) and temperature of 34.4°C. The predicted value of amygdalin content in the dried extract (25.42 g per 100 g) at these conditions was experimentally confirmed (25.30 g per 100 g of dried extract). Amygdalin (>90%) was isolated from the complex extraction mixture and structurally characterized by FT-IR, UV, and MS methods. PMID:25972881

  9. Optimization of technological procedure for amygdalin isolation from plum seeds (Pruni domesticae semen

    Directory of Open Access Journals (Sweden)

    Ivan M Savic

    2015-04-01

    Full Text Available The process of amygdalin extraction from plum seeds was optimized using central composite design (CCD and multilayer perceptron (MLP. The effect of time, ethanol concentration, solid-to-liquid ratio and temperature on the amygdalin content in the extracts was estimated using both mathematical models. The MLP 4-3-1 with exponential function in hidden layer and linear function in output layer was used for describing the extraction process. MLP model was more superior compared with CCD model due to better prediction ability. According to MLP model, the suggested optimal conditions are: time of 120 min, 100% (v/v ethanol, solid-to liquid ratio of 1:25 (m/v and temperature of 34.4 °C. The predicted value of amygdalin content in the dried extract (25.42 g per 100 g at these conditions was experimentally confirmed (25.30 g per 100 g of dried extract. Amygdalin (>90% was isolated from the complex extraction mixture and structurally characterized by FT-IR, UV and MS methods.

  10. An automated analysis workflow for optimization of force-field parameters using neutron scattering data

    Energy Technology Data Exchange (ETDEWEB)

    Lynch, Vickie E.; Borreguero, Jose M. [Neutron Data Analysis & Visualization Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 (United States); Bhowmik, Debsindhu [Computational Sciences & Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 (United States); Ganesh, Panchapakesan; Sumpter, Bobby G. [Center for Nanophase Material Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 (United States); Computational Sciences & Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 (United States); Proffen, Thomas E. [Neutron Data Analysis & Visualization Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 (United States); Goswami, Monojoy, E-mail: goswamim@ornl.gov [Center for Nanophase Material Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 (United States); Computational Sciences & Engineering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831 (United States)

    2017-07-01

    Graphical abstract: - Highlights: • An automated workflow to optimize force-field parameters. • Used the workflow to optimize force-field parameter for a system containing nanodiamond and tRNA. • The mechanism relies on molecular dynamics simulation and neutron scattering experimental data. • The workflow can be generalized to any other experimental and simulation techniques. - Abstract: Large-scale simulations and data analysis are often required to explain neutron scattering experiments to establish a connection between the fundamental physics at the nanoscale and data probed by neutrons. However, to perform simulations at experimental conditions it is critical to use correct force-field (FF) parameters which are unfortunately not available for most complex experimental systems. In this work, we have developed a workflow optimization technique to provide optimized FF parameters by comparing molecular dynamics (MD) to neutron scattering data. We describe the workflow in detail by using an example system consisting of tRNA and hydrophilic nanodiamonds in a deuterated water (D{sub 2}O) environment. Quasi-elastic neutron scattering (QENS) data show a faster motion of the tRNA in the presence of nanodiamond than without the ND. To compare the QENS and MD results quantitatively, a proper choice of FF parameters is necessary. We use an efficient workflow to optimize the FF parameters between the hydrophilic nanodiamond and water by comparing to the QENS data. Our results show that we can obtain accurate FF parameters by using this technique. The workflow can be generalized to other types of neutron data for FF optimization, such as vibrational spectroscopy and spin echo.

  11. Phase-Field Relaxation of Topology Optimization with Local Stress Constraints

    DEFF Research Database (Denmark)

    Stainko, Roman; Burger, Martin

    2006-01-01

    inequality constraints. We discretize the problem by finite elements and solve the arising finite-dimensional programming problems by a primal-dual interior point method. Numerical experiments for problems with local stress constraints based on different criteria indicate the success and robustness......We introduce a new relaxation scheme for structural topology optimization problems with local stress constraints based on a phase-field method. In the basic formulation we have a PDE-constrained optimization problem, where the finite element and design analysis are solved simultaneously...

  12. Statistical optimization of synthesis procedure and characterization of europium (III) molybdate nano-plates

    Energy Technology Data Exchange (ETDEWEB)

    Pourmortazavi, Seied Mahdi [Malek Ashtar University of Technology, Faculty of Material and Manufacturing Technologies, P. O. Box 16765-3454, Tehran (Iran, Islamic Republic of); Rahimi-Nasrabadi, Mehdi [Imam Hossein University, Nano Science Center, Tehran (Iran, Islamic Republic of); Fazli, Yousef [Islamic Azad University, Department of Chemistry, Faculty of Science, Arak Branch, Arak (Iran, Islamic Republic of); Mohammad-Zadeh, Mohammad [Sabzevar University of Medical Sciences, Department of Physiology and Pharmacology, School of Medicine, Sabzevar (Iran, Islamic Republic of)

    2015-06-15

    Europium (III) molybdate nano-plates were synthesized in this work via chemical precipitation route involving adding of europium (III) ion solution to the aqueous solution of molybdate reagent. Effects of some reaction variables such as concentrations of europium and molybdate ions, flow rate of europium reagent, and reactor temperature on the diameter of the synthesized europium (III) molybdate nano-plates were experimentally investigated by orthogonal array design. The results showed that the size of europium (III) molybdate nano-plates can be optimized by adjusting the concentrations of europium (III) and molybdate ions, as well as the reactional temperature. Europium (III) molybdate nano-plates prepared under the optimum conditions were characterized by X-ray powder diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy. (orig.)

  13. Improving the performance of the actinic inspection tool with an optimized alignment procedure

    International Nuclear Information System (INIS)

    Mochi, I.; Goldberg, K.A.; Naulleau, P.; Huh, Sungmin

    2009-01-01

    Extreme ultraviolet (EUV) microscopy is an important tool for the investigation of the performance of EUV masks, for detecting the presence and the characteristics of defects, and for evaluating the effectiveness of defect repair techniques. Aerial image measurement bypasses the difficulties inherent to photoresist imaging and enables high data collection speed and flexibility. It provides reliable and quick feedback for the development of masks and lithography system modeling methods. We operate the SEMATECH Berkeley Actinic Inspection Tool (AIT), a EUV microscope installed at the Advanced Light Source at Lawrence Berkeley National Laboratory. The AIT is equipped with several high-magnification Fresnel zoneplate lenses, with various numerical aperture values, that enable it image the reflective mask surface with various resolution and magnification settings. Although the AIT has undergone significant recent improvements in terms of imaging resolution and illumination uniformity, there is still room for improvement. In the AIT, an off-axis zoneplate lens collects the light coming from the sample and an image of the sample is projected onto an EUV-sensitive CCD camera. The simplicity of the optical system is particularly helpful considering that the AIT alignment has to be performed every time that a sample or a zoneplate is replaced. The alignment is sensitive to several parameters such as the lens position and orientation, the illumination direction and the sample characteristics. Since the AIT works in high vacuum, there is no direct access to the optics or to the sample during the alignment and the measurements. For all these reasons the alignment procedures and feedback can be complex, and in some cases can reduce the overall data throughput of the system. In this paper we review the main strategies and procedures that have been developed for quick and reliable alignments, and we describe the performance improvements we have achieved, in terms of aberration

  14. Improving the performance of the actinic inspection tool with an optimized alignment procedure

    Energy Technology Data Exchange (ETDEWEB)

    Mochi, I.; Goldberg, K.A.; Naulleau, P.; Huh, Sungmin

    2009-03-04

    Extreme ultraviolet (EUV) microscopy is an important tool for the investigation of the performance of EUV masks, for detecting the presence and the characteristics of defects, and for evaluating the effectiveness of defect repair techniques. Aerial image measurement bypasses the difficulties inherent to photoresist imaging and enables high data collection speed and flexibility. It provides reliable and quick feedback for the development of masks and lithography system modeling methods. We operate the SEMATECH Berkeley Actinic Inspection Tool (AIT), a EUV microscope installed at the Advanced Light Source at Lawrence Berkeley National Laboratory. The AIT is equipped with several high-magnification Fresnel zoneplate lenses, with various numerical aperture values, that enable it image the reflective mask surface with various resolution and magnification settings. Although the AIT has undergone significant recent improvements in terms of imaging resolution and illumination uniformity, there is still room for improvement. In the AIT, an off-axis zoneplate lens collects the light coming from the sample and an image of the sample is projected onto an EUV-sensitive CCD camera. The simplicity of the optical system is particularly helpful considering that the AIT alignment has to be performed every time that a sample or a zoneplate is replaced. The alignment is sensitive to several parameters such as the lens position and orientation, the illumination direction and the sample characteristics. Since the AIT works in high vacuum, there is no direct access to the optics or to the sample during the alignment and the measurements. For all these reasons the alignment procedures and feedback can be complex, and in some cases can reduce the overall data throughput of the system. In this paper we review the main strategies and procedures that have been developed for quick and reliable alignments, and we describe the performance improvements we have achieved, in terms of aberration

  15. Technical procedures for utilities and solid waste: Environmental Field Program, Deaf Smith County site, Texas: Final draft

    International Nuclear Information System (INIS)

    1987-08-01

    The evaluation of environmental issues and concerns and the addressing of statutory requirements are fundamental parts in the characterization of the site in Deaf Smith County, Texas for the US Department of Energy's Salt Repository Project (SRP). To ensure that the environmental field program comprehensively addresses the issues and requirements of the project, a site study plan (SSP) has been prepared for Utilities and Solid Waste considerations. This technical procedure (TP) has been developed to implement the field program described in the Utilities and Solid Waste Site Study Plan. The purpose and scope of the Utilities and Solid Waste Technical Procedure is to develop and implement a data collection procedure to fulfill the data base needs of the Utilities and Solid Waste SSP. The procedure describes a method of obtaining, assessing and verifying the capabilities of the regional service utilities and disposal contractors. This data base can be used to identify a preferred service source for the engineering contractor. The technical procedure was produced under the guidelines established in Technical Administrative Procedure No. 1.0, Preparation, Review and Approval of Technical Procedures

  16. An Optimized Online Verification Imaging Procedure for External Beam Partial Breast Irradiation

    International Nuclear Information System (INIS)

    Willis, David J.; Kron, Tomas; Chua, Boon

    2011-01-01

    The purpose of this study was to evaluate the capabilities of a kilovoltage (kV) on-board imager (OBI)-equipped linear accelerator in the setting of on-line verification imaging for external-beam partial breast irradiation. Available imaging techniques were optimized and assessed for image quality using a modified anthropomorphic phantom. Imaging dose was also assessed. Imaging techniques were assessed for physical clearance between patient and treatment machine using a volunteer. Nonorthogonal kV image pairs were identified as optimal in terms of image quality, clearance, and dose. After institutional review board approval, this approach was used for 17 patients receiving accelerated partial breast irradiation. Imaging was performed before every fraction verification with online correction of setup deviations >5 mm (total image sessions = 170). Treatment staff rated risk of collision and visibility of tumor bed surgical clips where present. Image session duration and detected setup deviations were recorded. For all cases, both image projections (n = 34) had low collision risk. Surgical clips were rated as well as visualized in all cases where they were present (n = 5). The average imaging session time was 6 min, 16 sec, and a reduction in duration was observed as staff became familiar with the technique. Setup deviations of up to 1.3 cm were detected before treatment and subsequently confirmed offline. Nonorthogonal kV image pairs allowed effective and efficient online verification for partial breast irradiation. It has yet to be tested in a multicenter study to determine whether it is dependent on skilled treatment staff.

  17. An optimization of a GPU-based parallel wind field module

    International Nuclear Information System (INIS)

    Pinheiro, André L.S.; Shirru, Roberto

    2017-01-01

    Atmospheric radionuclide dispersion systems (ARDS) are important tools to predict the impact of radioactive releases from Nuclear Power Plants and guide people evacuation from affected areas. Four modules comprise ARDS: Source Term, Wind Field, Plume Dispersion and Doses Calculations. The slowest is the Wind Field Module that was previously parallelized using the CUDA C language. The statement purpose of this work is to show the speedup gain with the optimization of the already parallel code of the GPU-based Wind Field module, based in WEST model (Extrapolated from Stability and Terrain). Due to the parallelization done in the wind field module, it was observed that some CUDA processors became idle, thus contributing to a reduction in speedup. It was proposed in this work a way of allocating these idle CUDA processors in order to increase the speedup. An acceleration of about 4 times can be seen in the comparative case study between the regular CUDA code and the optimized CUDA code. These results are quite motivating and point out that even after a parallelization of code, a parallel code optimization should be taken into account. (author)

  18. An optimization of a GPU-based parallel wind field module

    Energy Technology Data Exchange (ETDEWEB)

    Pinheiro, André L.S.; Shirru, Roberto [Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Pereira, Cláudio M.N.A., E-mail: apinheiro99@gmail.com, E-mail: schirru@lmp.ufrj.br, E-mail: cmnap@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    Atmospheric radionuclide dispersion systems (ARDS) are important tools to predict the impact of radioactive releases from Nuclear Power Plants and guide people evacuation from affected areas. Four modules comprise ARDS: Source Term, Wind Field, Plume Dispersion and Doses Calculations. The slowest is the Wind Field Module that was previously parallelized using the CUDA C language. The statement purpose of this work is to show the speedup gain with the optimization of the already parallel code of the GPU-based Wind Field module, based in WEST model (Extrapolated from Stability and Terrain). Due to the parallelization done in the wind field module, it was observed that some CUDA processors became idle, thus contributing to a reduction in speedup. It was proposed in this work a way of allocating these idle CUDA processors in order to increase the speedup. An acceleration of about 4 times can be seen in the comparative case study between the regular CUDA code and the optimized CUDA code. These results are quite motivating and point out that even after a parallelization of code, a parallel code optimization should be taken into account. (author)

  19. Optimization of a large integrated area development of gas fields offshore Sarawak, Malaysia

    International Nuclear Information System (INIS)

    Inyang, S.E.; Tak, A.N.H.; Costello, G.

    1995-01-01

    Optimizations of field development plans are routine in the industry. The size, schedule and nature of the upstream gas supply project to the second Malaysia LNG (MLNG Dua) plant in Bintulu, Sarawak made the need for extensive optimizations critical to realizing a robust and cost effective development scheme, and makes the work of more general interest. The project comprises the upstream development of 11 offshore fields for gas supply to MLNG Dua plant at an initial plateau production of 7.8 million tons per year of LNG. The gas fields span a large geographical area in medium water depths (up to 440 ft), and contain gas reserves of a distinctly variable gas quality. This paper describes the project optimization efforts aimed to ensure an upstream gas supply system effectiveness of over 99% throughout the project life while maintaining high safety and environmental standards and also achieving an economic development in an era of low hydrocarbon prices. Fifty percent of the first of the three phases of this gas supply project has already been completed and the first gas from these fields is scheduled to be available by the end of 1995

  20. Mitigation of Power frequency Magnetic Fields. Using Scale Invariant and Shape Optimization Methods

    Energy Technology Data Exchange (ETDEWEB)

    Salinas, Ener; Yueqiang Liu; Daalder, Jaap; Cruz, Pedro; Antunez de Souza, Paulo Roberto Jr; Atalaya, Juan Carlos; Paula Marciano, Fabianna de; Eskinasy, Alexandre

    2006-10-15

    The present report describes the development and application of two novel methods for implementing mitigation techniques of magnetic fields at power frequencies. The first method makes use of scaling rules for electromagnetic quantities, while the second one applies a 2D shape optimization algorithm based on gradient methods. Before this project, the first method had already been successfully applied (by some of the authors of this report) to electromagnetic designs involving pure conductive Material (e.g. copper, aluminium) which implied a linear formulation. Here we went beyond this approach and tried to develop a formulation involving ferromagnetic (i.e. non-linear) Materials. Surprisingly, we obtained good equivalent replacement for test-transformers by varying the input current. In spite of the validity of this equivalence constrained to regions not too close to the source, the results can still be considered useful, as most field mitigation techniques are precisely developed for reducing the magnetic field in regions relatively far from the sources. The shape optimization method was applied in this project to calculate the optimal geometry of a pure conductive plate to mitigate the magnetic field originated from underground cables. The objective function was a weighted combination of magnetic energy at the region of interest and dissipated heat at the shielding Material. To our surprise, shapes of complex structure, difficult to interpret (and probably even harder to anticipate) were the results of the applied process. However, the practical implementation (using some approximation of these shapes) gave excellent experimental mitigation factors.

  1. Investigations into the Optimization of Multi-Source Strength Brachytherapy Treatment Procedures

    International Nuclear Information System (INIS)

    Henderson, D. L.; Yoo, S.; Thomadsen, B.R.

    2002-01-01

    The goal of this project is to investigate the use of multi-strength and multi-specie radioactive sources in permanent prostate implant brachytherapy. In order to fulfill the requirement for an optimal dose distribution, the prescribed dose should be delivered to the target in a nearly uniform dose distribution while simultaneously sparing sensitive structures. The treatment plan should use a small number of needles and sources while satisfying the treatment requirements. The hypothesis for the use of multi-strength and/or multi-specie sources is that a better treatment plan using fewer sources and needles could be obtained than by treatment plans using single-strength sources could reduce the overall number of sources used for treatment. We employ a recently developed greedy algorithm based on the adjoint concept as the optimization search engine. The algorithm utilizes and ''adjoint ratio'', which provides a means of ranking source positions, as the pseudo-objective function. It ha s been shown that the greedy algorithm can solve the optimization problem efficiently and arrives at a clinically acceptable solution in less than 10 seconds. Our study was inclusive, that is there was no combination of sources that clearly stood out from the others and could therefore be considered the preferred set of sources for treatment planning. Source strengths of 0.2 mCi (low), 0.4 mCi (medium), and 0.6 mCi (high) of 125 I in four different combinations were used for the multi-strength source study. The combination of high- and medium-strength sources achieved a more uniform target dose distribution due to few source implants whereas the combination of low-and medium-strength sources achieved better sparing of sensitive tissues including that of the single-strength 0.4 mCi base case. 125 I at 0.4 mCi and 192 Ir at 0.12 mCi and 0.25 mCi source strengths were used for the multi-specie source study. This study also proved inconclusive , Treatment plans using a combination of two 0

  2. Simultaneous sand control and liner cement system: keeping well productivity by optimizing drilling and completion operations in mature fields

    Energy Technology Data Exchange (ETDEWEB)

    Sa, Andrea Nicolino de; Silva, Dayana Nunes e; Calderon, Agostinho [Petroleo Brasileiro S.A. (PETROBRAS), Rio de janeiro, RJ (Brazil)

    2012-07-01

    The need to reduce oil extraction costs by increasing the recovery factor in mature fields unconsolidated sandstone reservoirs motivated the development of drilling and completion techniques that integrate the various interfaces of engineering the well, resulting in a final well configuration that provides maximum oil production at a lower cost. Due to the continued growth of drilling and completion of new wells or deviation of old wells in the design of mesh density field with an advanced degree of exploitation, PETROBRAS took the challenge to seek options for projects well, in order to maintain productivity and reduce their construction time, with the optimization of drilling and sand control systems. To achieve these goals, PETROBRAS developed the SCARS - Simultaneous Sand Control and Liner Cementing System, a pioneer technique in the global oil industry, which consists of a one trip sequence of operations in which sand control screens and liner are installed followed by the open hole gravel pack operation performed with the alpha and beta waves deposition technique, using a non aqueous system as a carrier fluid. The sequence is completed by liner cementing in the same trip. The great success of this project was based on the definition of a specific application scenario and demands allowing optimization of the system. This project started with the development of a non aqueous system as a gravel pack carrier fluid in order to perform an open hole gravel pack with the alpha/beta wave deposition technique along with the development and optimization of SCARS procedures. This article details the planning and execution phases of this project and also presents a broad description of the technical aspects. (author)

  3. Arsenic and iron removal from groundwater by oxidation–coagulation at optimized pH: Laboratory and field studies

    International Nuclear Information System (INIS)

    Bordoloi, Shreemoyee; Nath, Suresh K.; Gogoi, Sweety; Dutta, Robin K.

    2013-01-01

    Highlights: • Arsenic and iron removed by a systematic oxidation–coagulation at optimized pH. • Used KMnO 4 as oxidant and FeCl 3 as coagulant in presence of NaHCO 3 . • Field trial results are highly encouraging. • The method is efficient, safe, simple and low-cost. • The method is suitable for rural application in developing countries. -- Abstract: A three-step treatment process involving (i) mild alkaline pH-conditioning by NaHCO 3 ; (ii) oxidation of arsenite and ferrous ions by KMnO 4 , itself precipitating as insoluble MnO 2 under the pH condition; and (iii) coagulation by FeCl 3 has been used for simultaneous removal of arsenic and iron ions from water. The treated water is filtered after a residence time of 1–2 h. Laboratory batch experiments were performed to optimize the doses. A field trial was performed with an optimized recipe at 30 households and 5 schools at some highly arsenic affected villages in Assam, India. Simultaneous removals of arsenic from initial 0.1–0.5 mg/L to about 5 μg/L and iron from initial 0.3–5.0 mg/L to less than 0.1 mg/L have been achieved along with final pH between 7.0 and 7.5 after residence time of 1 h. The process also removes other heavy elements, if present, without leaving any additional toxic residue. The small quantity of solid sludge containing mainly ferrihydrite with adsorbed arsenate passes the toxicity characteristic leaching procedure (TCLP) test. The estimated recurring cost is approximately USD 0.16 per/m 3 of purified water. A high efficiency, an extremely low cost, safety, non-requirement of power and simplicity of operation make the technique potential for rural application

  4. Optimization of heliostat field layout in solar central receiver systems on annual basis using differential evolution algorithm

    International Nuclear Information System (INIS)

    Atif, Maimoon; Al-Sulaiman, Fahad A.

    2015-01-01

    Highlights: • Differential evolution optimization model was developed to optimize the heliostat field. • Five optical parameters were considered for the optimization of the optical efficiency. • Optimization using insolation weighted and un-weighted annual efficiency are developed. • The daily averaged annual optical efficiency was calculated to be 0.5023 while the monthly was 0.5025. • The insolation weighted daily averaged annual efficiency was 0.5634. - Abstract: Optimization of a heliostat field is an essential task to make a solar central receiver system effective because major optical losses are associated with the heliostat fields. In this study, a mathematical model was developed to effectively optimize the heliostat field on annual basis using differential evolution, which is an evolutionary algorithm. The heliostat field layout optimization is based on the calculation of five optical performance parameters: the mirror or the heliostat reflectivity, the cosine factor, the atmospheric attenuation factor, the shadowing and blocking factor, and the intercept factor. This model calculates all the aforementioned performance parameters at every stage of the optimization, until the best heliostat field layout based on annual performance is obtained. Two different approaches were undertaken to optimize the heliostat field layout: one with optimizing insolation weighted annual efficiency and the other with optimizing the un-weighted annual efficiency. Moreover, an alternate approach was also proposed to efficiently optimize the heliostat field in which the number of computational time steps was considerably reduced. It was observed that the daily averaged annual optical efficiency was calculated to be 0.5023 as compared to the monthly averaged annual optical efficiency, 0.5025. Moreover, the insolation weighted daily averaged annual efficiency of the heliostat field was 0.5634 for Dhahran, Saudi Arabia. The code developed can be used for any other

  5. Technical procedures for water resources: Volume 3, Environmental Field Program, Deaf Smith County Site, Texas: Final draft

    International Nuclear Information System (INIS)

    1987-08-01

    To ensure that the environmental field program comprehensively addresses the issues and requirements of the project, a site study plan (SSP) has been prepared for Water Resources (ONWI, 1987). This technical procedure (TP) has been developed to implement the field program described in the Water Resources Site Study Plan. This procedure provides the general method for the field collection of water and sediment samples from playa lakes using an Alpha horizontal type sampler or equivalent or a peristaltic pump for water and a KB-coring devise or ponar grab for sediments. The samples will be preserved and then shipped to a laboratory for analysis. The water quality and sediment samples will be collected as part of the surface-water quality field study described in the Site Plan for Water Resources. 15 refs., 5 figs., 3 tabs

  6. Radiofrequency thermoablation of primary non-spinal osteoid osteoma: optimization of the procedure

    Energy Technology Data Exchange (ETDEWEB)

    Rimondi, E.; Malaguti, M.C.; Ciminari, R.; Albisinni, U. [Istituti Ortopedici Rizzoli, Radiology Department, Bologna (Italy); Bianchi, Giuseppe; Del Baldo, A.; Mercuri, M. [Istituti Ortopedici Rizzoli, V Divisione, Bologna (Italy)

    2005-07-01

    Osteoid osteoma is a small benign tumor that requires treatment due to the intense pain it causes. Surgical therapy has been the ablative technique of choice after a failure of medical therapy. Recently, numerous less invasive, alternative procedures have been proposed: drill trepanation with or without ethanol injections, cryoablation, and thermoablation with laser or radiofrequency. The aim of this review is to retrospectively assess the effect of radiofrequency (RF) thermoablation in the treatment of primary non-spinal osteoid osteoma. From June 2001 to July 2003, we treated 106 patients affected by osteoid osteoma with RF thermoablation. Five patients with spinal osteoid osteoma and four with a previously treated osteoma were excluded from the study. In this paper, we assess the results obtained in a selected group of 97 primary non-spinal osteoid osteoma. The lesions were predominantly in the metaphysics of the femur. Central nidus calcifications were frequent and there was no prevalence for which side they occurred. Primary success was achieved in 82 patients (85%), while we obtained secondary success in 15 patients (15%). In two patients (2%), pain persisted between the two treatments and failed to be resolved, even after the second treatment; therefore, surgical excision was performed and complete resolution was obtained. No complications were reported. In conclusion, our results confirm that the treatment of choice for non-spinal osteoid osteoma is RF thermoablation, offering several advantages over ablative techniques. (orig.)

  7. Virtual solar field - An opportunity to optimize transient processes in line-focus CSP power plants

    Science.gov (United States)

    Noureldin, Kareem; Hirsch, Tobias; Pitz-Paal, Robert

    2017-06-01

    Optimizing solar field operation and control is a key factor to improve the competitiveness of line-focus solar thermal power plants. However, the risks of assessing new and innovative control strategies on operational power plants hinder such optimizations and result in applying more conservative control schemes. In this paper, we describe some applications for a whole solar field transient in-house simulation tool developed at the German Aerospace Centre (DLR), the Virtual Solar Field (VSF). The tool offers a virtual platform to simulate real solar fields while coupling the thermal and hydraulic conditions of the field with high computational efficiency. Using the tool, developers and operator can probe their control strategies and assess the potential benefits while avoiding the high risks and costs. In this paper, we study the benefits gained from controlling the loop valves and of using direct normal irradiance maps and forecasts for the field control. Loop valve control is interesting for many solar field operators since it provides a high degree of flexibility to the control of the solar field through regulating the flow rate in each loop. This improves the reaction to transient condition, such as passing clouds and field start-up in the morning. Nevertheless, due to the large number of loops and the sensitivity of the field control to the valve settings, this process needs to be automated and the effect of changing the setting of each valve on the whole field control needs to be taken into account. We used VSF to implement simple control algorithms to control the loop valves and to study the benefits that could be gained from using active loop valve control during transient conditions. Secondly, we study how using short-term highly spatially-resolved DNI forecasts provided by cloud cameras could improve the plant energy yield. Both cases show an improvement in the plant efficiency and outlet temperature stability. This paves the road for further

  8. Imaging local cerebral blood flow by xenon-enhanced computed tomography - technical optimization procedures

    International Nuclear Information System (INIS)

    Meyer, J.S.; Shinohara, T.; Imai, A.; Kobari, M.; Solomon, E.

    1988-01-01

    Methods are described for non-invasive, computer-assisted serial scanning throughout the human brain during eight minutes of inhalation of 27%-30% xenon gas in order to measure local cerebral blood flow (LCBF). Optimized xenon-enhanced computed tomography (XeCT) was achieved by 5-second scanning at one-minute intervals utilizing a state-of-the-art CT scanner and rapid delivery of xenon gas via a face mask. Values for local brain-blood partition coefficients (Lλ) measured in vivo were utilized to calculate LCBF values. Previous methods assumed Lλ values to be normal, introducing the risk of systematic errors, because Lλ values differ throughout normal brain and may be altered by disease. Color-coded maps of Lλ and LCBF values were formatted directly onto CT images for exact correlation of function with anatomic and pathologic observations (spatial resolution: 26.5 cubic mm). Results were compared among eight normal volunteers, aged between 50 and 88 years. Mean cortical gray matter blood flow was 46.3 ± 7.7, for subcortical gray matter it was 50.3 ± 13.2 and for white matter it was 18.8 ± 3.2. Modern CT scanners provide stability, improved signal to noise ratio and minimal radiation scatter. Combining these advantages with rapid xenon saturation of the blood provides correlations of Lλ and LCBF with images of normal and abnormal brain in a safe, useful and non-invasive manner. (orig.)

  9. Optimization of phenol extraction procedures for preparation of RNA from mammalian lymphoid organs

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, G.D.; Sellin, H.G.; Novelli, G.D.

    1978-07-01

    Methods have been developed to optimize the extraction of RNA from mammalian lymphoid organs (spleen) with respect to both quantity and quality of RNA and with minimal DNA contamination. Nuclease inhibitors, including diethyl pyrocarbonate, polyvinyl sulfate, and bentonite were used in the initial disruption of the tissue, which was accomplished by blender, Dounce homogenizer, or preparation of a cell suspension. Seven buffer systems, varying with respect to pH, detergent, and NaCl concentration, were used in the initial extraction with phenol, and the temperature of extraction was also varied. Protocols involving the selective use of naphthalene 1.5-disulfonic acid and sodium dodecyl sulfate were developed to provide an initial RNA extract with minimal DNA content. Dounce homogenization, followed by separate treatment of nuclear and cytosol fractions, was found to be the most effective technique, both in terms of RNA yield (averaging 76%) and the quality of RNA recovered (as judged by gel electrophoresis). RNA from blender preparations contained larger amounts of DNA and RNA yield was decreased to 54%. RNA extracted from spleen cell suspensions was of poor quality and gave very poor yield (27%).

  10. Imaging local cerebral blood flow by xenon-enhanced computed tomography - technical optimization procedures

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, J.S.; Shinohara, T.; Imai, A.; Kobari, M.; Sakai, F.; Hata, T.; Oravez, W.T.; Timpe, G.M.; Deville, T.; Solomon, E.

    1988-08-01

    Methods are described for non-invasive, computer-assisted serial scanning throughout the human brain during eight minutes of inhalation of 27%-30% xenon gas in order to measure local cerebral blood flow (LCBF). Optimized xenon-enhanced computed tomography (XeCT) was achieved by 5-second scanning at one-minute intervals utilizing a state-of-the-art CT scanner and rapid delivery of xenon gas via a face mask. Values for local brain-blood partition coefficients (Llambda) measured in vivo were utilized to calculate LCBF values. Previous methods assumed Llambda values to be normal, introducing the risk of systematic errors, because Llambda values differ throughout normal brain and may be altered by disease. Color-coded maps of Llambda and LCBF values were formatted directly onto CT images for exact correlation of function with anatomic and pathologic observations (spatial resolution: 26.5 cubic mm). Results were compared among eight normal volunteers, aged between 50 and 88 years. Mean cortical gray matter blood flow was 46.3 +- 7.7, for subcortical gray matter it was 50.3 +- 13.2 and for white matter it was 18.8 +- 3.2. Modern CT scanners provide stability, improved signal to noise ratio and minimal radiation scatter. Combining these advantages with rapid xenon saturation of the blood provides correlations of Llambda and LCBF with images of normal and abnormal brain in a safe, useful and non-invasive manner.

  11. Predictive simulations and optimization of nanowire field-effect PSA sensors including screening

    KAUST Repository

    Baumgartner, Stefan; Heitzinger, Clemens; Vacic, Aleksandar; Reed, Mark A

    2013-01-01

    We apply our self-consistent PDE model for the electrical response of field-effect sensors to the 3D simulation of nanowire PSA (prostate-specific antigen) sensors. The charge concentration in the biofunctionalized boundary layer at the semiconductor-electrolyte interface is calculated using the propka algorithm, and the screening of the biomolecules by the free ions in the liquid is modeled by a sensitivity factor. This comprehensive approach yields excellent agreement with experimental current-voltage characteristics without any fitting parameters. Having verified the numerical model in this manner, we study the sensitivity of nanowire PSA sensors by changing device parameters, making it possible to optimize the devices and revealing the attributes of the optimal field-effect sensor. © 2013 IOP Publishing Ltd.

  12. Predictive simulations and optimization of nanowire field-effect PSA sensors including screening

    KAUST Repository

    Baumgartner, Stefan

    2013-05-03

    We apply our self-consistent PDE model for the electrical response of field-effect sensors to the 3D simulation of nanowire PSA (prostate-specific antigen) sensors. The charge concentration in the biofunctionalized boundary layer at the semiconductor-electrolyte interface is calculated using the propka algorithm, and the screening of the biomolecules by the free ions in the liquid is modeled by a sensitivity factor. This comprehensive approach yields excellent agreement with experimental current-voltage characteristics without any fitting parameters. Having verified the numerical model in this manner, we study the sensitivity of nanowire PSA sensors by changing device parameters, making it possible to optimize the devices and revealing the attributes of the optimal field-effect sensor. © 2013 IOP Publishing Ltd.

  13. Strategies for discovery and optimization of thermoelectric materials: Role of real objects and local fields

    Science.gov (United States)

    Zhu, Hao; Xiao, Chong

    2018-06-01

    Thermoelectric materials provide a renewable and eco-friendly solution to mitigate energy shortages and to reduce environmental pollution via direct heat-to-electricity conversion. Discovery of the novel thermoelectric materials and optimization of the state-of-the-art material systems lie at the core of the thermoelectric society, the basic concept behind these being comprehension and manipulation of the physical principles and transport properties regarding thermoelectric materials. In this mini-review, certain examples for designing high-performance bulk thermoelectric materials are presented from the perspectives of both real objects and local fields. The highlights of this topic involve the Rashba effect, Peierls distortion, local magnetic field, and local stress field, which cover several aspects in the field of thermoelectric research. We conclude with an overview of future developments in thermoelectricity.

  14. Quantum dynamics manipulation using optimal control theory in the presence of laser field noise

    Science.gov (United States)

    Kumar, Praveen; Malinovskaya, Svetlana A.

    2010-08-01

    We discuss recent advances in optimal control theory (OCT) related to the investigation of the impact of control field noise on controllability of quantum dynamics. Two numerical methods, the gradient method and the iteration method, are paid particular attention. We analyze the problem of designing noisy control fields to maximize the vibrational transition probability in diatomic quantum systems, e.g. the HF and OH molecules. White noise is used as an additive random variable in the amplitude of the control field. It is demonstrated that the convergence is faster in the presence of noise and population transfer is increased by 0.04% for small values of noise compared to the field amplitude.

  15. Field implementation of geological steering techniques optimizes drilling in highly-deviated and horizontal wells

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, C. E.; Illfelder, H. M. J.; Pineda, G.

    1998-12-31

    Field implementation of an integrated wellsite geological steering service is described. The service provides timely, useful feedback from real-time logging-while-drilling (LWD) measurements for making immediate course corrections. Interactive multi-dimensional displays of both the geological and petrophysical properties of the formation being penetrated by the wellbore are a prominent feature of the service; the optimization of the drilling is the result of the visualization afforded by the displays. The paper reviews forward modelling techniques, provides a detailed explanation of the principles underlying this new application, and illustrates the application by examples from the field. 5 refs., 1 tab., 8 figs.

  16. Assessment of grammar optimizes language tasks for the intracarotid amobarbital procedure.

    Science.gov (United States)

    Połczyńska, Monika; Kuhn, Taylor; You, S Christine; Walshaw, Patricia; Curtiss, Susan; Bookheimer, Susan

    2017-11-01

    A previous study showed that assessment of language laterality could be improved by adding grammar tests to the recovery phase of the intracarotid amobarbital procedure (IAP) (Połczyńska et al. 2014). The aim of this study was to further investigate the extent to which grammar tests lateralize language function during the recovery phase of the IAP in a larger patient sample. Forty patients with drug-resistant epilepsy (14 females, thirty-two right-handed, mean age 38.5years, SD=10.6) participated in this study. On EEG, 24 patients had seizures originating in the left hemisphere (LH), 13 in the right hemisphere (RH), and 4 demonstrated mixed seizure origin. Thirty participants (75%) had bilateral injections, and ten (25%) had unilateral injections (five RH and five LH). Based on results from the encoding phase, we segregated our study participants to a LH language dominant and a mixed dominance group. In the recovery phase of the IAP, the participants were administered a new grammar test (the CYCLE-N) and a standard language test. We analyzed the laterality index measure and effect sizes in the two tests. In the LH-dominant group, the CYCLE-N generated more profound language deficits in the recovery phase than the standard after injection to either hemisphere (pgrammar tasks was still higher than for the standard tests. Critically, the CYCLE-N administered in the recovery phase was nearly as effective as the standard tests given during the encoding phase. The results may be significant for individuals with epilepsy undergoing IAP. The grammar tests may be a highly efficient measure for lateralizing language function in the recovery phase. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Optimized extraction of polysaccharides from corn silk by pulsed electric field and response surface quadratic design.

    Science.gov (United States)

    Zhao, Wenzhu; Yu, Zhipeng; Liu, Jingbo; Yu, Yiding; Yin, Yongguang; Lin, Songyi; Chen, Feng

    2011-09-01

    Corn silk is a traditional Chinese herbal medicine, which has been widely used for treatment of some diseases. In this study the effects of pulsed electric field on the extraction of polysaccharides from corn silk were investigated. Polysaccharides in corn silk were extracted by pulsed electric field and optimized by response surface methodology (RSM), based on a Box-Behnken design (BBD). Three independent variables, including electric field intensity (kV cm(-1) ), ratio of liquid to raw material and pulse duration (µs), were investigated. The experimental data were fitted to a second-order polynomial equation and also profiled into the corresponding 3-D contour plots. Optimal extraction conditions were as follows: electric field intensity 30 kV cm(-1) , ratio of liquid to raw material 50, and pulse duration 6 µs. Under these condition, the experimental yield of extracted polysaccharides was 7.31% ± 0.15%, matching well with the predicted value. The results showed that a pulsed electric field could be applied to extract value-added products from foods and/or agricultural matrix. Copyright © 2011 Society of Chemical Industry.

  18. Synthetical optimization of hydraulic radius and acoustic field for thermoacoustic cooler

    International Nuclear Information System (INIS)

    Kang Huifang; Li Qing; Zhou Gang

    2009-01-01

    It is well known that the acoustic field and the hydraulic radius of the regenerator play key roles in thermoacoustic processes. The optimization of hydraulic radius strongly depends on the acoustic field in the regenerator. This paper investigates the synthetical optimization of hydraulic radius and acoustic field which is characterized by the ratio of the traveling wave component to the standing wave component. In this paper, we discussed the heat flux, cooling power, temperature gradient and coefficient of performance of thermoacoustic cooler with different combinations of hydraulic radiuses and acoustic fields. The calculation results show that, in the cooler's regenerator, due to the acoustic wave, the heat is transferred towards the pressure antinodes in the pure standing wave, while the heat is transferred in the opposite direction of the wave propagation in the pure traveling wave. The better working condition for the regenerator appears in the traveling wave phase region of the like-standing wave, where the directions of the heat transfer by traveling wave component and standing wave component are the same. Otherwise, the small hydraulic radius is not a good choice for acoustic field with excessively high ratio of traveling wave, and the small hydraulic radius is only needed by the traveling wave phase region of like-standing wave.

  19. Transforming data into decisions to optimize the recovery of the Saih Rawl Field in Oman

    Energy Technology Data Exchange (ETDEWEB)

    Dozier, G C [Society of Petroleum Engineers, Dubai (United Arab Emirates); [Schlumberger Oilfield Services, Dubai (United Arab Emirates); Giacon, P [Society of Petroleum Engineers, Dubai (United Arab Emirates); [Petroleum Development of Oman (Oman)

    2006-07-01

    The Saih Rawl field of Oman has been producing for more than 5 years from the Barik and Miqrat Formations. Well productivity depends greatly on the effectiveness of hydraulic fracturing and other operating practices. Productivity is further complicated by the changing mechanical and reservoir properties related to depletion and intralayer communication. In this study, a systematic approach was used by a team of operators and service companies to optimize well production within a one-year time period. The approach involved a dynamic integration of historical data and new information technologies and engineering diagnostics to identify the key parameters that influence productivity and to optimize performance according to current analyses. In particular, historical pressure trends by unit were incorporated with theoretical assumptions validated by indirect field evidence. Onsite decision-making resulted in effective placement of fracture treatments. The approach has produced some of the highest producing wells in the field's history. It was concluded that optimization and maximization of well productivity requires multidiscipline inputs that should be managed through structured workflow that includes not only the classical simulation design inputs but entails the entire process from design to execution with particular emphasis on cleanup practices and induced fluid damage. 6 refs., 2 tabs., 25 figs.

  20. High Fidelity Multi-Objective Design Optimization of a Downscaled Cusped Field Thruster

    Directory of Open Access Journals (Sweden)

    Thomas Fahey

    2017-11-01

    Full Text Available The Cusped Field Thruster (CFT concept has demonstrated significantly improved performance over the Hall Effect Thruster and the Gridded Ion Thruster; however, little is understood about the complexities of the interactions and interdependencies of the geometrical, magnetic and ion beam properties of the thruster. This study applies an advanced design methodology combining a modified power distribution calculation and evolutionary algorithms assisted by surrogate modeling to a multi-objective design optimization for the performance optimization and characterization of the CFT. Optimization is performed for maximization of performance defined by five design parameters (i.e., anode voltage, anode current, mass flow rate, and magnet radii, simultaneously aiming to maximize three objectives; that is, thrust, efficiency and specific impulse. Statistical methods based on global sensitivity analysis are employed to assess the optimization results in conjunction with surrogate models to identify key design factors with respect to the three design objectives and additional performance measures. The research indicates that the anode current and the Outer Magnet Radius have the greatest effect on the performance parameters. An optimal value for the anode current is determined, and a trend towards maximizing anode potential and mass flow rate is observed.

  1. Monitoring of the radioactive liquid effluents discharged from IPEN-CNEN/SP. Optimization of the procedures adopted

    International Nuclear Information System (INIS)

    Seki, C.R.

    1990-01-01

    The main purpose of a radioactive liquid effluents monitoring of a nuclear installation is to determine the amount of radioactivity discharged to the environment, as well as, to verify if this activity is below the authorized discharge limits established by the competent authority. Although this control has been established on a routine basis since the beginning of operation of the nuclear installations available at IPEN, the growing of such facilities in the last years has implied in an increase in the number of samples to be analyzed. The aim of this work is, therefore, to optimize the procedures adopted in the Environmental Monitoring Division of IPEN-CNEN/SP for the activity measurement of the liquid effluents discharged to the environment. Since these effluents are discharged to Pinheiros river, which presents a high dilution factor, a study is also carried out in order to verify if the activity present can be measured by the equipment available. (author)

  2. Optimization of magnetic field system for glass spherical tokamak GLAST-III

    International Nuclear Information System (INIS)

    Ahmad, Zahoor; Ahmad, S; Naveed, M A; Deeba, F; Javeed, M Aqib; Batool, S; Hussain, S; Vorobyov, G M

    2017-01-01

    GLAST-III (Glass Spherical Tokamak) is a spherical tokamak with aspect ratio A = 2. The mapping of its magnetic system is performed to optimize the GLAST-III tokamak for plasma initiation using a Hall probe. Magnetic field from toroidal coils shows 1/ R dependence which is typical with spherical tokamaks. Toroidal field (TF) coils can produce 875 Gauss field, an essential requirement for electron cyclotron resonance assisted discharge. The central solenoid (CS) of GLAST-III is an air core solenoid and requires compensation coils to reduce unnecessary magnetic flux inside the vessel region. The vertical component of magnetic field from the CS in the vacuum vessel region is reduced to 1.15 Gauss kA −1 with the help of a differential loop. The CS of GLAST can produce flux change up to 68 mVs. Theoretical and experimental results are compared for the current waveform of TF coils using a combination of fast and slow capacitor banks. Also the magnetic field produced by poloidal field (PF) coils is compared with theoretically predicted values. It is found that calculated results are in good agreement with experimental measurement. Consequently magnetic field measurements are validated. A tokamak discharge with 2 kA plasma current and pulse length 1 ms is successfully produced using different sets of coils. (paper)

  3. Computer–Based Procedures for Nuclear Power Plant Field Workers: Preliminary Results from Two Evaluation Studies

    Energy Technology Data Exchange (ETDEWEB)

    Katya L Le Blanc; Johanna H Oxstrand

    2013-10-01

    The Idaho National Laboratory and participants from the U.S. nuclear industry are collaborating on a research effort aimed to augment the existing guidance on computer-based procedure (CBP) design with specific guidance on how to design CBP user interfaces such that they support procedure execution in ways that exceed the capabilities of paper-based procedures (PBPs) without introducing new errors. Researchers are employing an iterative process where the human factors issues and interface design principles related to CBP usage are systematically addressed and evaluated in realistic settings. This paper describes the process of developing a CBP prototype and the two studies conducted to evaluate the prototype. The results indicate that CBPs may improve performance by reducing errors, but may increase the time it takes to complete procedural tasks.

  4. Field procedures for the uranium hydrogeochemical and stream sediment reconnaissance as used by the Los Alamos Scientific Laboratory

    International Nuclear Information System (INIS)

    Sharp, R.R. Jr.; Aamodt, P.L.

    1978-04-01

    This manual of field procedures is prepared to aid personnel involved in the field sampling of natural waters and waterborne sediment for the Los Alamos Scientific Laboratory (LASL) as part of the US Department of Energy (DOE) Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) of the National Uranium Resource Evaluation (NURE) program. It presents the procedural guidelines to be followed by all contractors, contractor employees, and others who collect, treat, or otherwise handle samples taken for the LASL as part of the HSSR program. Part I relates to all sampling in the conterminous states of the US for which the LASL is responsible to the DOE for carrying out the HSSR work. Part II describes procedures to be followed for HSSR work, using helicopter support, in the state of Alaska. The objective of the manual is to insure that consistent techniques are used throughout the survey. If any procedure is unclear or cannot be followed, telephone collect to Group G-5, LASL, (505) 667-7590, for further instructions. No variations in the specific procedures should be made without prior approval of the LASL

  5. Universal field matching in craniospinal irradiation by a background-dose gradient-optimized method.

    Science.gov (United States)

    Traneus, Erik; Bizzocchi, Nicola; Fellin, Francesco; Rombi, Barbara; Farace, Paolo

    2018-01-01

    The gradient-optimized methods are overcoming the traditional feathering methods to plan field junctions in craniospinal irradiation. In this note, a new gradient-optimized technique, based on the use of a background dose, is described. Treatment planning was performed by RayStation (RaySearch Laboratories, Stockholm, Sweden) on the CT scans of a pediatric patient. Both proton (by pencil beam scanning) and photon (by volumetric modulated arc therapy) treatments were planned with three isocenters. An 'in silico' ideal background dose was created first to cover the upper-spinal target and to produce a perfect dose gradient along the upper and lower junction regions. Using it as background, the cranial and the lower-spinal beams were planned by inverse optimization to obtain dose coverage of their relevant targets and of the junction volumes. Finally, the upper-spinal beam was inversely planned after removal of the background dose and with the previously optimized beams switched on. In both proton and photon plans, the optimized cranial and the lower-spinal beams produced a perfect linear gradient in the junction regions, complementary to that produced by the optimized upper-spinal beam. The final dose distributions showed a homogeneous coverage of the targets. Our simple technique allowed to obtain high-quality gradients in the junction region. Such technique universally works for photons as well as protons and could be applicable to the TPSs that allow to manage a background dose. © 2017 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

  6. Optimization of Photospheric Electric Field Estimates for Accurate Retrieval of Total Magnetic Energy Injection

    Science.gov (United States)

    Lumme, E.; Pomoell, J.; Kilpua, E. K. J.

    2017-12-01

    Estimates of the photospheric magnetic, electric, and plasma velocity fields are essential for studying the dynamics of the solar atmosphere, for example through the derivative quantities of Poynting and relative helicity flux and using the fields to obtain the lower boundary condition for data-driven coronal simulations. In this paper we study the performance of a data processing and electric field inversion approach that requires only high-resolution and high-cadence line-of-sight or vector magnetograms, which we obtain from the Helioseismic and Magnetic Imager (HMI) onboard Solar Dynamics Observatory (SDO). The approach does not require any photospheric velocity estimates, and the lacking velocity information is compensated for using ad hoc assumptions. We show that the free parameters of these assumptions can be optimized to reproduce the time evolution of the total magnetic energy injection through the photosphere in NOAA AR 11158, when compared to recent state-of-the-art estimates for this active region. However, we find that the relative magnetic helicity injection is reproduced poorly, reaching at best a modest underestimation. We also discuss the effect of some of the data processing details on the results, including the masking of the noise-dominated pixels and the tracking method of the active region, neither of which has received much attention in the literature so far. In most cases the effect of these details is small, but when the optimization of the free parameters of the ad hoc assumptions is considered, a consistent use of the noise mask is required. The results found in this paper imply that the data processing and electric field inversion approach that uses only the photospheric magnetic field information offers a flexible and straightforward way to obtain photospheric magnetic and electric field estimates suitable for practical applications such as coronal modeling studies.

  7. Generalized filtering of laser fields in optimal control theory: application to symmetry filtering of quantum gate operations

    International Nuclear Information System (INIS)

    Schroeder, Markus; Brown, Alex

    2009-01-01

    We present a modified version of a previously published algorithm (Gollub et al 2008 Phys. Rev. Lett.101 073002) for obtaining an optimized laser field with more general restrictions on the search space of the optimal field. The modification leads to enforcement of the constraints on the optimal field while maintaining good convergence behaviour in most cases. We demonstrate the general applicability of the algorithm by imposing constraints on the temporal symmetry of the optimal fields. The temporal symmetry is used to reduce the number of transitions that have to be optimized for quantum gate operations that involve inversion (NOT gate) or partial inversion (Hadamard gate) of the qubits in a three-dimensional model of ammonia.

  8. Autoblocking dose-limiting normal structures within a radiation treatment field: 3-D computer optimization of 'unconventional' field arrangements

    International Nuclear Information System (INIS)

    Bates, Brian A.; Cullip, Timothy J.; Rosenman, Julian G.

    1995-01-01

    Purpose/Objective: To demonstrate that one can obtain a homogeneous dose distribution within a specified gross tumor volume (GTV) while severely limiting the dose to a structure surrounded by that tumor volume. We present three clinical examples below. Materials and Methods: Using planning CT scans from previously treated patients, we designed variety of radiation treatment plans in which the dose-critical normal structure was blocked, even if it meant blocking some of the tumor. To deal with the resulting dose inhomogeneities within the tumor, we introduced 3D compensation. Examples presented here include (1) blocking the spinal cord segment while treating an entire vertebral body, (2) blocking both kidneys while treating the entire peritoneal cavity, and (3) blocking one parotid gland while treating the oropharynx in its entirety along with regional nodes. A series of multiple planar and non-coplanar beam templates with automatic anatomic blocking and field shaping were designed for each scenario. Three-dimensional compensators were designed that gave the most homogeneous dose-distribution for the GTV. For each beam, rays were cast from the beam source through a 2D compensator grid and out through the tumor. The average tumor dose along each ray was then used to adjust the compensator thickness over successive iterations to achieve a uniform average dose. DVH calculations for the GTV, normal structures, and the 'auto-blocked' structure were made and used for inter-plan comparisons. Results: These optimized treatment plans successfully decreased dose to the dose-limiting structure while at the same time preserving or even improving the dose distribution to the tumor volume as compared to traditional treatment plans. Conclusion: The use of 3D compensation allows one to obtain dose distributions that are, theoretically, at least, far superior to those in common clinical use. Sensible beam templates, auto-blocking, auto-field shaping, and 3D compensators form a

  9. On a mean field game optimal control approach modeling fast exit scenarios in human crowds

    KAUST Repository

    Burger, Martin; Di Francesco, Marco; Markowich, Peter A.; Wolfram, Marie Therese

    2013-01-01

    The understanding of fast exit and evacuation situations in crowd motion research has received a lot of scientific interest in the last decades. Security issues in larger facilities, like shopping malls, sports centers, or festivals necessitate a better understanding of the major driving forces in crowd dynamics. In this paper we present an optimal control approach modeling fast exit scenarios in pedestrian crowds. The model is formulated in the framework of mean field games and based on a parabolic optimal control problem. We consider the case of a large human crowd trying to exit a room as fast as possible. The motion of every pedestrian is determined by minimizing a cost functional, which depends on his/her position and velocity, the overall density of people, and the time to exit. This microscopic setup leads in a mean-field formulation to a nonlinear macroscopic optimal control problem, which raises challenging questions for the analysis and numerical simulations.We discuss different aspects of the mathematical modeling and illustrate them with various computational results. ©2013 IEEE.

  10. Application of optimal control theory to laser heating of a plasma in a solenoidal magnetic field

    International Nuclear Information System (INIS)

    Neal, R.D.

    1975-01-01

    Laser heating of a plasma column confined by a solenoidal magnetic field is studied via modern optimal control techniques. A two-temperature, constant pressure model is used for the plasma so that the temperature and density are functions of time and location along the plasma column. They are assumed to be uniform in the radial direction so that refraction of the laser beam does not occur. The laser intensity used as input to the column at one end is taken as the control variable and plasma losses are neglected. The localized behavior of the plasma heating dynamics is first studied and conventional optimal control theory applied. The distributed parameter optimal control problem is next considered with minimum time to reach a specified final ion temperature criterion as the objective. Since the laser intensity can only be directly controlled at the input end of the plasma column, a boundary control situation results. The problem is unique in that the control is the boundary value of one of the state variables. The necessary conditions are developed and the problem solved numerically for typical plasma parameters. The problem of maximizing the space-time integral of neutron production rate in the plasma is considered for a constant distributed control problem where the laser intensity is assumed fixed at maximum and the external magnetic field is taken as a control variable

  11. On a mean field game optimal control approach modeling fast exit scenarios in human crowds

    KAUST Repository

    Burger, Martin

    2013-12-01

    The understanding of fast exit and evacuation situations in crowd motion research has received a lot of scientific interest in the last decades. Security issues in larger facilities, like shopping malls, sports centers, or festivals necessitate a better understanding of the major driving forces in crowd dynamics. In this paper we present an optimal control approach modeling fast exit scenarios in pedestrian crowds. The model is formulated in the framework of mean field games and based on a parabolic optimal control problem. We consider the case of a large human crowd trying to exit a room as fast as possible. The motion of every pedestrian is determined by minimizing a cost functional, which depends on his/her position and velocity, the overall density of people, and the time to exit. This microscopic setup leads in a mean-field formulation to a nonlinear macroscopic optimal control problem, which raises challenging questions for the analysis and numerical simulations.We discuss different aspects of the mathematical modeling and illustrate them with various computational results. ©2013 IEEE.

  12. MDCT evaluation of pulmonary embolism in children and young adults following a lateral tunnel Fontan procedure: optimizing contrast-enhancement techniques

    International Nuclear Information System (INIS)

    Prabhu, Sanjay P.; Mahmood, Soran; Sena, Laureen; Lee, Edward Y.

    2009-01-01

    Pulmonary embolism (PE) is a life-threatening thromboembolic complication in patients who have undergone a Fontan procedure for augmenting pulmonary blood flow in the setting of single-ventricle physiology. In patients following a Fontan procedure, lack of proper contrast agent mixing in the right atrium and sluggish, low-velocity blood flow within the Fontan circulation often results in suboptimal contrast enhancement within the pulmonary artery for evaluating PE. Unfortunately, there is a paucity of information describing the optimal contrast-enhancement technique with multidetector CT (MDCT) for evaluating PE in children and young adults following a Fontan procedure. We illustrate the MDCT imaging findings of suboptimal contrast enhancement within the pulmonary artery, which can be mistaken for PE, in patients following a lateral Fontan procedure, and we discuss MDCT techniques to optimize contrast enhancement within the pulmonary artery in these patients for evaluating PE. The MDCT imaging findings in pediatric and young adult patients following a lateral Fontan procedure and with clinically suspected PE are illustrated. We describe intravenous contrast agent injection techniques that can be used to optimize the contrast enhancement in the pulmonary artery in patients following a lateral Fontan procedure. The use of a suboptimal contrast-enhancement technique led to initial misdiagnosis and incomplete evaluation of PE in the three patients following a lateral Fontan procedure. Imaging in two patients showed that optimal evaluation of thrombosis in the Fontan pathway and PE in the pulmonary arteries can be successfully achieved with simultaneous upper- and lower-limb injections of contrast agent. This series demonstrates that suboptimal contrast enhancement can result in misdiagnosis or incomplete evaluation of PE in children and young adults following a lateral Fontan procedure. Careful attention to optimizing contrast enhancement during MDCT examination for

  13. Plasma grid design for optimized filter field configuration for the NBI test facility ELISE

    International Nuclear Information System (INIS)

    Nocentini, R.; Gutser, R.; Heinemann, B.; Froeschle, M.; Riedl, R.

    2009-01-01

    Maintenance-free RF sources for negative hydrogen ions with moderate extraction areas (100-200 cm 2 ) have been successfully developed in the last years at IPP Garching in the test facilities BATMAN and MANITU. A facility with larger extraction area (1000 cm 2 ), ELISE, is being designed with a 'half-size' ITER-like extraction system, pulsed ion acceleration up to 60 kV for 10 s and plasma generation up to 1 h. Due to the large size of the source, the magnetic filter field (FF) cannot be produced solely by permanent magnets. Therefore, an additional magnetic field produced by current flowing through the plasma grid (PG current) is required. The filter field homogeneity and the interaction with the electron suppression magnetic field have been studied in detail by finite element method (FEM) during the ELISE design phase. Significant improvements regarding the field homogeneity have been introduced compared to the ITER reference design. Also, for the same PG current a 50% higher field in front of the grid has been achieved by optimizing the plasma grid geometry. Hollow spaces have been introduced in the plasma grid for a more homogeneous PG current distribution. The introduction of hollow spaces also allows the insertion of permanent magnets in the plasma grid.

  14. Technical procedures for implementation of acoustics site studies, Deaf Smith County site, Texas: Environmental Field Program: Preliminary draft

    International Nuclear Information System (INIS)

    1987-09-01

    The purpose and scope of the technical procedure for processing data from the tethered meteorological system are covered. Definitions, interfaces, and concurrent data needs are also addressed. This technical procedure describes how to control, organize, verify, and archive tethered meteorological system data. These data will be received at the processing location from the field measurement location and are part of the characterization of the Deaf Smith County Site, Texas for the salt repository program. These measurements will be made in support of the sound propagation study and are a result of environmental data requirements for acoustics. 6 refs., 15 figs., 5 tabs

  15. Topology optimization of the permanent magnet type MRI considering the magnetic field homogeneity

    International Nuclear Information System (INIS)

    Lee, Junghoon; Yoo, Jeonghoon

    2010-01-01

    This study is to suggest a concept design of the permanent magnet (PM) type magnetic resonance imaging (MRI) device based on the topology optimization method. The pulse currents in the gradient coils in the MRI device will introduce the effect of eddy currents in ferromagnetic material and it may worsen the quality of imaging. To equalize the magnetic flux in the PM type MRI device for good imaging, the eddy current effect in the ferromagnetic material must be reduced. This study attempts to use the topology optimization scheme for equalizing the magnetic flux in the measuring domain of the PM type MRI device using that the magnetic flux can be calculated directly by a commercial finite element analysis package. The density method is adopted for topology optimization and the sensitivity of the objective function is computed according to the density change of each finite element in the design domain. As a result, optimal shapes of the pole of the PM type MRI device can be obtained. The commercial package, ANSYS, is used for analyzing the magnetic field problem and obtaining the resultant magnetic flux.

  16. A Stochastic Inversion Method for Potential Field Data: Ant Colony Optimization

    Science.gov (United States)

    Liu, Shuang; Hu, Xiangyun; Liu, Tianyou

    2014-07-01

    Simulating natural ants' foraging behavior, the ant colony optimization (ACO) algorithm performs excellently in combinational optimization problems, for example the traveling salesman problem and the quadratic assignment problem. However, the ACO is seldom used to inverted for gravitational and magnetic data. On the basis of the continuous and multi-dimensional objective function for potential field data optimization inversion, we present the node partition strategy ACO (NP-ACO) algorithm for inversion of model variables of fixed shape and recovery of physical property distributions of complicated shape models. We divide the continuous variables into discrete nodes and ants directionally tour the nodes by use of transition probabilities. We update the pheromone trails by use of Gaussian mapping between the objective function value and the quantity of pheromone. It can analyze the search results in real time and promote the rate of convergence and precision of inversion. Traditional mapping, including the ant-cycle system, weaken the differences between ant individuals and lead to premature convergence. We tested our method by use of synthetic data and real data from scenarios involving gravity and magnetic anomalies. The inverted model variables and recovered physical property distributions were in good agreement with the true values. The ACO algorithm for binary representation imaging and full imaging can recover sharper physical property distributions than traditional linear inversion methods. The ACO has good optimization capability and some excellent characteristics, for example robustness, parallel implementation, and portability, compared with other stochastic metaheuristics.

  17. A New Method for Determining Optimal Regularization Parameter in Near-Field Acoustic Holography

    Directory of Open Access Journals (Sweden)

    Yue Xiao

    2018-01-01

    Full Text Available Tikhonov regularization method is effective in stabilizing reconstruction process of the near-field acoustic holography (NAH based on the equivalent source method (ESM, and the selection of the optimal regularization parameter is a key problem that determines the regularization effect. In this work, a new method for determining the optimal regularization parameter is proposed. The transfer matrix relating the source strengths of the equivalent sources to the measured pressures on the hologram surface is augmented by adding a fictitious point source with zero strength. The minimization of the norm of this fictitious point source strength is as the criterion for choosing the optimal regularization parameter since the reconstructed value should tend to zero. The original inverse problem in calculating the source strengths is converted into a univariate optimization problem which is solved by a one-dimensional search technique. Two numerical simulations with a point driven simply supported plate and a pulsating sphere are investigated to validate the performance of the proposed method by comparison with the L-curve method. The results demonstrate that the proposed method can determine the regularization parameter correctly and effectively for the reconstruction in NAH.

  18. Optimization of confinement in a toroidal plasma subject to strong radial electric fields

    International Nuclear Information System (INIS)

    Roth, J.R.

    1977-01-01

    A preliminary report on the identification and optimization of independent variables which affect the ion density and confinement time in a bumpy torus plasma is presented. The independent variables include the polarity, position, and number of the midplane electrode rings, the method of gas injection, and the polarity and strength of a weak vertical magnetic field. Some characteristic data taken under condition when most of the independent variables were optimized are presented. The highest value of the electron number density on the plasma axis is 3.2 x 10 to the 12th power/cc, the highest ion heating efficiency is 47 percent, and the longest particle containment time is 2.0 milliseconds

  19. Optimization of well field operation: case study of søndersø waterworks, Denmark

    DEFF Research Database (Denmark)

    Hansen, Annette Kirstine; Madsen, Henrik; Bauer-Gottwein, Peter

    2013-01-01

    An integrated hydrological well field model (WELLNES) that predicts the water level and energy consumption in the production wells of a waterworks is used to optimize the management of a waterworks with the speed of the pumps as decision variables. The two-objective optimization problem...... variable-speed pumps, it is possible to save 42% of the specific energy consumption and at the same time improve the risk objective function. The payback period of investing in new variable speed pumps is only 3.1 years, due to the large savings in electricity. The case study illustrates the efficiency...... of minimizing the risk of contamination from a nearby contaminated site and minimizing the energy consumption of the waterworks is solved by genetic algorithms. In comparison with historical values, significant improvements in both objectives can be obtained. If the existing on/off pumps are changed to new...

  20. Intermolecular Force Field Parameters Optimization for Computer Simulations of CH4 in ZIF-8

    Directory of Open Access Journals (Sweden)

    Phannika Kanthima

    2016-01-01

    Full Text Available The differential evolution (DE algorithm is applied for obtaining the optimized intermolecular interaction parameters between CH4 and 2-methylimidazolate ([C4N2H5]− using quantum binding energies of CH4-[C4N2H5]− complexes. The initial parameters and their upper/lower bounds are obtained from the general AMBER force field. The DE optimized and the AMBER parameters are then used in the molecular dynamics (MD simulations of CH4 molecules in the frameworks of ZIF-8. The results show that the DE parameters are better for representing the quantum interaction energies than the AMBER parameters. The dynamical and structural behaviors obtained from MD simulations with both sets of parameters are also of notable differences.

  1. Research on the Flow Field and Structure Optimization in Cyclone Separator with Downward Exhaust Gas

    Directory of Open Access Journals (Sweden)

    Wang Weiwei

    2017-01-01

    Full Text Available A numerical software analysis of the turbulent and strongly swirling flow field of a cyclone separator with downward exhaust gas and its performances is described. The ANSYS 14.0 simulations based on DPM model are also used in the investigation. A new set of geometrical design has been optimized to achieve minimum pressure drop and maximum separation efficiency. A comparison of numerical simulation of the new design confirm the superior performance of the new design compared to the conventional design. The influence of the structure parameters such as the length of the guide pipe, the shape of the guide, the inlet shape on the separation performance was analyzed in this research. This research result has certain reference value for cyclone separator design and performance optimization.

  2. Frequency locking of a field-widened Michelson interferometer based on optimal multi-harmonics heterodyning.

    Science.gov (United States)

    Cheng, Zhongtao; Liu, Dong; Zhou, Yudi; Yang, Yongying; Luo, Jing; Zhang, Yupeng; Shen, Yibing; Liu, Chong; Bai, Jian; Wang, Kaiwei; Su, Lin; Yang, Liming

    2016-09-01

    A general resonant frequency locking scheme for a field-widened Michelson interferometer (FWMI), which is intended as a spectral discriminator in a high-spectral-resolution lidar, is proposed based on optimal multi-harmonics heterodyning. By transferring the energy of a reference laser to multi-harmonics of different orders generated by optimal electro-optic phase modulation, the heterodyne signal of these multi-harmonics through the FWMI can reveal the resonant frequency drift of the interferometer very sensitively within a large frequency range. This approach can overcome the locking difficulty induced by the low finesse of the FWMI, thus contributing to excellent locking accuracy and lock acquisition range without any constraint on the interferometer itself. The theoretical and experimental results are presented to verify the performance of this scheme.

  3. Optimization of a near-field thermophotovoltaic system operating at low temperature and large vacuum gap

    Science.gov (United States)

    Lim, Mikyung; Song, Jaeman; Kim, Jihoon; Lee, Seung S.; Lee, Ikjin; Lee, Bong Jae

    2018-05-01

    The present work successfully achieves a strong enhancement in performance of a near-field thermophotovoltaic (TPV) system operating at low temperature and large-vacuum-gap width by introducing a hyperbolic-metamaterial (HMM) emitter, multilayered graphene, and an Au-backside reflector. Design variables for the HMM emitter and the multilayered-graphene-covered TPV cell are optimized for maximizing the power output of the near-field TPV system with the genetic algorithm. The near-field TPV system with the optimized configuration results in 24.2 times of enhancement in power output compared with that of the system with a bulk emitter and a bare TPV cell. Through the analysis of the radiative heat transfer together with surface-plasmon-polariton (SPP) dispersion curves, it is found that coupling of SPPs generated from both the HMM emitter and the multilayered-graphene-covered TPV cell plays a key role in a substantial increase in the heat transfer even at a 200-nm vacuum gap. Further, the backside reflector at the bottom of the TPV cell significantly increases not only the conversion efficiency, but also the power output by generating additional polariton modes which can be readily coupled with the existing SPPs of the HMM emitter and the multilayered-graphene-covered TPV cell.

  4. Field-Based Optimal Placement of Antennas for Body-Worn Wireless Sensors

    Directory of Open Access Journals (Sweden)

    Łukasz Januszkiewicz

    2016-05-01

    Full Text Available We investigate a case of automated energy-budget-aware optimization of the physical position of nodes (sensors in a Wireless Body Area Network (WBAN. This problem has not been presented in the literature yet, as opposed to antenna and routing optimization, which are relatively well-addressed. In our research, which was inspired by a safety-critical application for firefighters, the sensor network consists of three nodes located on the human body. The nodes communicate over a radio link operating in the 2.4 GHz or 5.8 GHz ISM frequency band. Two sensors have a fixed location: one on the head (earlobe pulse oximetry and one on the arm (with accelerometers, temperature and humidity sensors, and a GPS receiver, while the position of the third sensor can be adjusted within a predefined region on the wearer’s chest. The path loss between each node pair strongly depends on the location of the nodes and is difficult to predict without performing a full-wave electromagnetic simulation. Our optimization scheme employs evolutionary computing. The novelty of our approach lies not only in the formulation of the problem but also in linking a fully automated optimization procedure with an electromagnetic simulator and a simplified human body model. This combination turns out to be a computationally effective solution, which, depending on the initial placement, has a potential to improve performance of our example sensor network setup by up to about 20 dB with respect to the path loss between selected nodes.

  5. Efficacy of sublingual administration of detomidine gel for sedation of horses undergoing veterinary and husbandry procedures under field conditions.

    Science.gov (United States)

    Gardner, Rachel B; White, Gary W; Ramsey, Deborah S; Boucher, Joseph F; Kilgore, W Randal; Huhtinen, Mirja K

    2010-12-15

    To determine whether sublingual detomidine gel administration to horses would be effective in providing an appropriate degree of sedation and restraint to facilitate completion of veterinary and husbandry procedures under field conditions. Multicenter, prospective, randomized, blinded, placebo-controlled clinical study. 270 client-owned horses known to require sedation or strong restraint to enable veterinary and husbandry procedures to be performed. Horses randomly received a single dose of detomidine gel (0.04 mg/kg [0.018 mg/lb]) or placebo gel administered sublingually. Horses were sedated to facilitate cleaning the prepuce, cutting of hair with electric clippers, hoof trimming or application of shoes, manual dental floating (ie, rasping or filing of the teeth to remove irregularities), nasogastric passage of a stomach tube or endoscope, and radiography. The primary determinant of efficacy was an assessment by a veterinarian on the ability or inability to successfully conduct the procedure. 171 horses met all the study protocol criteria. One hundred twenty-nine horses were treated with detomidine. The procedure was completed successfully for 76% (98/129) of the detomidine-treated horses, while the procedure was completed successfully for only 7% (3/42) of the placebo-treated horses. The percentage of horses in which the procedure was successfully completed was significantly different between detomidine-treated horses and placebo-treated horses. No serious adverse effects were reported. Detomidine gel administered to horses sublingually at a dose of 0.04 mg/kg provided an appropriate degree of sedation and restraint to facilitate completion of veterinary and husbandry procedures in horses known to require sedation for such procedures.

  6. Special features in choosing a development procedure for deep gas condensate fields with small reserves

    Energy Technology Data Exchange (ETDEWEB)

    Rassokhin, G V; Soshnin, N M

    1971-01-01

    In planning the development and production schedule for fields with small gas-condensate reserves, the following factors need to be considered: capital investment per unit of production, value of produced gas, ultimate recovered reserves, geological structure of the field, depth of well, heterogeneity of producing sands, etc. The importance of such factors is discussed and it is shown that for small fields, the parameter of minimum net expense cannot be used as a planning tool. Both geological and economic factors must be included in field development.

  7. Investigation and optimization of the magnetic field configuration in high-power impulse magnetron sputtering

    International Nuclear Information System (INIS)

    Yu, He; Meng, Liang; Szott, Matthew M; Meister, Jack T; Cho, Tae S; Ruzic, David N

    2013-01-01

    An effort to optimize the magnetic field configuration specifically for high-power impulse magnetron sputtering (HiPIMS) was made. Magnetic field configurations with different field strengths, race track widths and race track patterns were designed using COMSOL. Their influence on HiPIMS plasma properties was investigated using a 36 cm diameter copper target. The I–V discharge characteristics were measured. The temporal evolution of electron temperature (T e ) and density (n e ) was studied employing a triple Langmuir probe, which was also scanned in the whole discharge region to characterize the plasma distribution and transport. Based on the studies, a closed path for electrons to drift along was still essential in HiPIMS in order to efficiently confine electrons and achieve a high pulse current. Very dense plasmas (10 19 –10 20 m −3 ) were generated in front of the race tracks during the pulse, and expanded downstream afterwards. As the magnetic field strength increased from 200 to 800 G, the expansion became faster and less isotropic, i.e. more directional toward the substrate. The electric potential distribution accounted for these effects. Varied race track widths and patterns altered the plasma distribution from the target to the substrate. A spiral-shaped magnetic field design was able to produce superior plasma uniformity on the substrate in addition to improved target utilization. (paper)

  8. Standardization of 2-phenoxyethanol as anesthetic for juvenile Brycon cephalus (Gunther, 1869: the use in field procedures

    Directory of Open Access Journals (Sweden)

    Inoue Luis Antônio Kioshi Aoki

    2004-01-01

    Full Text Available Hyper motility is a negative factor in fish handling procedures due to the risks of damages to the animals. Chemicals are widely used to anesthetize fish during biometry and many other handling procedures. 2-Phenoxyethanol is largely employed, but many studies are necessary about tropical fish responses. The present research evaluated the anesthesia induction time for juvenile matrinxã submitted to eight different levels of 2-phenoxyethanol. The range of 2-phenoxyethanol concentration was 250-600mg liter-1. Induction time of anesthesia decreased as a function of 2-phenoxyethanol concentrations. Fish were safely anesthetized approximately after one minute of exposure to 2-phenoxyethanol batches in concentrations above 400mg/liter, and the recover period was about one minute for all anesthetic concentrations. 2-Phenoxyethanol is a safe anesthetic for juvenile matrinxã even in exposures up to 600mg liter-1 being recommended for many field procedures of fish handling.

  9. Optimization of autonomous magnetic field sensor consisting of giant magnetoimpedance sensor and surface acoustic wave transducer

    KAUST Repository

    Li, Bodong; Morsy, Ahmed Mohamed Aly; Kosel, Jü rgen

    2012-01-01

    This paper presents a novel autonomous thin film magnetic field sensor consisting of a tri-layer giant magnetoimpedance sensor and a surface acoustic wave transponder. Double and single electrode interdigital transducer (IDT) designs are employed and compared. The integrated sensor is fabricated using standard microfabrication technology. The results show the double electrode IDT has an advantage in terms of the sensitivity. In order to optimize the matching component, a simulation based on P-matrix is carried out. A maximum change of 2.4 dB of the reflection amplitude and a sensitivity of 0.34 dB/Oe are obtained experimentally. © 2012 IEEE.

  10. Optimization of autonomous magnetic field sensor consisting of giant magnetoimpedance sensor and surface acoustic wave transducer

    KAUST Repository

    Li, Bodong

    2012-11-01

    This paper presents a novel autonomous thin film magnetic field sensor consisting of a tri-layer giant magnetoimpedance sensor and a surface acoustic wave transponder. Double and single electrode interdigital transducer (IDT) designs are employed and compared. The integrated sensor is fabricated using standard microfabrication technology. The results show the double electrode IDT has an advantage in terms of the sensitivity. In order to optimize the matching component, a simulation based on P-matrix is carried out. A maximum change of 2.4 dB of the reflection amplitude and a sensitivity of 0.34 dB/Oe are obtained experimentally. © 2012 IEEE.

  11. Optimal laser heating of plasmas confined in strong solenoidal magnetic fields

    International Nuclear Information System (INIS)

    Vitela, J.; Akcasu, A.Z.

    1987-01-01

    Optimal Control Theory is used to analyze the laser-heating of plasmas confined in strong solenoidal magnetic fields. Heating strategies that minimize a linear combination of heating time and total energy spent by the laser system are found. A numerical example is used to illustrate the theory. Results of this example show that by an appropriate modulation of the laser intensity, significant savings in the laser energy are possible with only slight increases in the heating time. However, results may depend strongly on the initial state of the plasma and on the final ion temperature. (orig.)

  12. Field Synergy Analysis and Optimization of the Thermal Behavior of Lithium Ion Battery Packs

    Directory of Open Access Journals (Sweden)

    Hongwen He

    2017-01-01

    Full Text Available In this study, a three dimensional (3D modeling has been built for a lithium ion battery pack using the field synergy principle to obtain a better thermal distribution. In the model, the thermal behavior of the battery pack was studied by reducing the maximum temperature, improving the temperature uniformity and considering the difference between the maximum and maximum temperature of the battery pack. The method is further verified by simulation results based on different environmental temperatures and discharge rates. The thermal behavior model demonstrates that the design and cooling policy of the battery pack is crucial for optimizing the air-outlet patterns of electric vehicle power cabins.

  13. Optimization of reagent concentration for radioiodination of rat C-peptide II in development of radioimmunoassay procedure for rats

    Directory of Open Access Journals (Sweden)

    B R Manupriya

    2018-01-01

    Full Text Available Rat C-peptide is a polypeptide molecule made up of 31 amino acids and secreted from pancreas into circulation in two isoforms I and II. Quantification of rat C-peptide II in rat serum is important as it is directly related to the diagnosis of carbohydrate metabolism abnormalities, pancreatic performance analysis, monitoring of hypoglycemia, and diabetes-related illness in rat model. The aim of the present work is to develop a tracer by chloramine-T method for radioimmunoassay (RIA procedure and to determine the optimum amount of chloramine-T required for the preparation of stable radioiodinated product with a specific activity of around 24.97 MBq/μg, corresponding to 1 125I atom per molecule of the peptide. Tyrosylated rat C-peptide II was selected for the radioiodination procedure as rat C-peptide II does not contain either tyrosine or histidine which is mandatory for the incorporation of 125I atom to the rat C-peptide II. Tyrosylated rat C-peptide II was subjected to radioiodination by chloramine-T method with different concentrations of chloramine-T and sodium metabisulfite (MBS to obtain a stable radiolabeled compound. Optimized reaction conditions relating to the concentration of chloramine-T (10 μg and MBS (20 μg yielded a stable 125I-rat C-peptide II with specific activity of 21.01 MBq/μg corresponding to 0.84 125I atoms per molecule of the peptide. Preparation of high integrity tracer of rat C-peptide II was achieved by combining one molecule of oxidant (chloramine-T and two molecule of reductant (MBS.

  14. Reduced medical and occupational exposures by optimizing working procedures in fluoroscopy equipment in the University Hospital of Santa Maria (RS)

    International Nuclear Information System (INIS)

    Weis, Guilherme L.; Claus, Thiago V.; Baumhardt, Tadeu; Shuch, Luiz A.

    2013-01-01

    This work seeks to reduce medical (patient) and occupational (workers) exposure by standardizing resources available in fluoroscopy equipment used in interventional procedures. Such procedures use transportable surgical arch type fluoroscopy equipment, with applications in orthopedics, angiography and pacemaker implantation. Improper use of these devices generates excessive radiation doses in both patients and the medical staff. It is observed that the equipment after being connected to the grid, is pre-selected to work in continuous fluoroscopy and no additional filtration, producing higher doses of radiation. For specific applications, changes in protocols should be undertaken according to medical indication. This work used a fluoroscopy equipment Shimadzu Active Opescope two radiation monitoring equipment, brand Radcal, models 9010 and 9015, two ionization chambers, of 60 cc and 180 cc and a low contrast phantom and a catheter, information that simulate the human body. Incidences were performed by changing the conditions of exposure as frame rates (fps - frames per second) and additional filtration. For each composition parameters was generated and filed an image, with the extent of their respective doses. These images were evaluated by radiologists. In more extreme cases we obtained a reduction of a factor 25 in occupational exposure (medical personnel) using the pulsed with the greatest 2 fps additional filter (0.3 mm Cu) compared to continuous system without any additional filtration. In medical exposure (of patients), decreased by a factor 39, the same conditions described above. With these arguments it is justified the optimization and standardization of the equipment used in fluoroscopy, which besides providing a dose reduction the patient and the medical personnel, increases the life of the X-ray tube while maintaining the quality of medical diagnosis. (author)

  15. Cost Finding Principles and Procedures. Preliminary Field Review Edition. Technical Report 26.

    Science.gov (United States)

    Ziemer, Gordon; And Others

    This report is part of the Larger Cost Finding Principles Project designed to develop a uniform set of standards, definitions, and alternative procedures that will use accounting and statistical data to find the full cost of resources utilized in the process of producing institutional outputs. This technical report describes preliminary procedures…

  16. Technical procedures for land use, Deaf Smith County site, Texas: Environmental Field Program: Final draft

    International Nuclear Information System (INIS)

    1987-09-01

    This volume contains Technical Procedures pursuant to the Land Use Site Study Plan including land use data acquisition, land use/land cover map compilation, verification of land use/land cover map accuracy, and land use/land cover data analysis. 22 refs., 5 figs

  17. Catalase measurement: A new field procedure for rapidly estimating microbial loads in fuels and water-bottoms

    Energy Technology Data Exchange (ETDEWEB)

    Passman, F.J. [Biodeterioration Control Associates, Inc., Chicago, IL (United States); Daniels, D.A. [Basic Fuel Services, Dover, NJ (United States); Chesneau, H.F.

    1995-05-01

    Low-grade microbial infections of fuel and fuel systems generally go undetected until they cause major operational problems. Three interdependent factors contribute to this: mis-diagnosis, incorrect or inadequate sampling procedures and perceived complexity of microbiological testing procedures. After discussing the first two issues, this paper describes a rapid field test for estimating microbial loads in fuels and associated water. The test, adapted from a procedure initially developed to measure microbial loads in metalworking fluids, takes advantage of the nearly universal presence of the enzyme catalase in the microbes that contaminated fuel systems. Samples are reacted with a peroxide-based reagent; liberating oxygen gas. The gas generates a pressure-head in a reaction tube. At fifteen minutes, a patented, electronic pressure-sensing device is used to measure that head-space pressure. The authors present both laboratory and field data from fuels and water-bottoms, demonstrating the excellent correlation between traditional viable test data (acquired after 48-72 hours incubation) and catalase test data (acquired after 15 min.-4 hours). We conclude by recommending procedures for developing a failure analysis data-base to enhance our industry`s understanding of the relationship between uncontrolled microbial contamination and fuel performance problems.

  18. Water Quality & Pollutant Source Monitoring: Field and Laboratory Procedures. Training Manual.

    Science.gov (United States)

    Office of Water Program Operations (EPA), Cincinnati, OH. National Training and Operational Technology Center.

    This training manual presents material on techniques and instrumentation used to develop data in field monitoring programs and related laboratory operations concerned with water quality and pollution monitoring. Topics include: collection and handling of samples; bacteriological, biological, and chemical field and laboratory methods; field…

  19. Procedure for field axes measurement, beam indication adjustment, and figure of convergence determination within performance tests for radiation therapy equipment

    Energy Technology Data Exchange (ETDEWEB)

    Quast, U; Krause, K; Rassow, J [Essen Univ. (Gesamthochschule) (Germany, F.R.). Abt. fuer Klinische Strahlenphysik

    1976-09-01

    A routine measuring procedure for the verification of radiation field axes and figure of convergence within a spatial resolution of +- 0.5 mm is described. Measurements are done in two parallel planes in a certain distance before and behind the presumed isocentre. The used test arrangement permits rapid check and controlled adjustment of the alignment of beam or isocentre indicating devices for all isocentric radiation therapy equipment.

  20. Quality assurance procedure for assessing mechanical accuracy of a radiation field center in stereotactic radiotherapy

    International Nuclear Information System (INIS)

    Tatsumi, Daisaku; Ienaga, Akinori; Nakada, Ryosei; Yomoda, Akane; Inoue, Makoto; Ichida, Takao; Hosono, Masako

    2012-01-01

    Stereotactic radiotherapy requires a quality assurance (QA) program that ensures the mechanical accuracy of a radiation field center. We have proposed a QA method for achieving the above requirement by conducting the Winston Lutz test using an electronic portal image device (EPID). An action limit was defined as three times the standard deviation. Then, the action limits for mean deviations of the radiation field center during collimator rotation, gantry rotation, and couch rotation in clockwise and counterclockwise resulted in 0.11 mm, 0.52 mm, 0.37 mm, and 0.41 mm respectively. Two years after the QA program was launched, the mean deviation of the radiation field center during gantry rotation exceeded the above action limit. Consequently, a mechanical adjustment for the gantry was performed, thereby restoring the accuracy of the radiation field center. A field center shift of 0.5 mm was also observed after a micro multi-leaf collimator was unmounted. (author)

  1. Optimization of electret ionization chambers for dosimetry in mixed neutron-gamma fields

    International Nuclear Information System (INIS)

    Doerschel, B.; Pretzsch, G.

    1984-01-01

    The properties of combination dosemeters consisting of two air-filled electret ionization chambers in mixed neutron-gamma fields have been investigated. The first chamber, polyethylene-walled, is sensitive to neutrons and gamma rays, the second, having walls of teflon, is sensitive to gamma rays only. The properties of the dosemeters are determined by the resulting errors and the measuring range. As both properties depend on the dimensions of the electret ionization chambers they have been taken into account in optimizing the dimensions. The results show that with the use of the dosemeters the effective dose equivalent in mixed neutron-gamma fields can be determined nearly independently of the spectra. The lower detection limit is less than 1 mSv and the maximum uncertainty of dose measurements about 12%. (author)

  2. Variable-Field Analytical Ultracentrifugation: I. Time-Optimized Sedimentation Equilibrium

    Science.gov (United States)

    Ma, Jia; Metrick, Michael; Ghirlando, Rodolfo; Zhao, Huaying; Schuck, Peter

    2015-01-01

    Sedimentation equilibrium (SE) analytical ultracentrifugation (AUC) is a gold standard for the rigorous determination of macromolecular buoyant molar masses and the thermodynamic study of reversible interactions in solution. A significant experimental drawback is the long time required to attain SE, which is usually on the order of days. We have developed a method for time-optimized SE (toSE) with defined time-varying centrifugal fields that allow SE to be attained in a significantly (up to 10-fold) shorter time than is usually required. To achieve this, numerical Lamm equation solutions for sedimentation in time-varying fields are computed based on initial estimates of macromolecular transport properties. A parameterized rotor-speed schedule is optimized with the goal of achieving a minimal time to equilibrium while limiting transient sample preconcentration at the base of the solution column. The resulting rotor-speed schedule may include multiple over- and underspeeding phases, balancing the formation of gradients from strong sedimentation fluxes with periods of high diffusional transport. The computation is carried out in a new software program called TOSE, which also facilitates convenient experimental implementation. Further, we extend AUC data analysis to sedimentation processes in such time-varying centrifugal fields. Due to the initially high centrifugal fields in toSE and the resulting strong migration, it is possible to extract sedimentation coefficient distributions from the early data. This can provide better estimates of the size of macromolecular complexes and report on sample homogeneity early on, which may be used to further refine the prediction of the rotor-speed schedule. In this manner, the toSE experiment can be adapted in real time to the system under study, maximizing both the information content and the time efficiency of SE experiments. PMID:26287634

  3. Optimal placement of active braces by using PSO algorithm in near- and far-field earthquakes

    Science.gov (United States)

    Mastali, M.; Kheyroddin, A.; Samali, B.; Vahdani, R.

    2016-03-01

    One of the most important issues in tall buildings is lateral resistance of the load-bearing systems against applied loads such as earthquake, wind and blast. Dual systems comprising core wall systems (single or multi-cell core) and moment-resisting frames are used as resistance systems in tall buildings. In addition to adequate stiffness provided by the dual system, most tall buildings may have to rely on various control systems to reduce the level of unwanted motions stemming from severe dynamic loads. One of the main challenges to effectively control the motion of a structure is limitation in distributing the required control along the structure height optimally. In this paper, concrete shear walls are used as secondary resistance system at three different heights as well as actuators installed in the braces. The optimal actuator positions are found by using optimized PSO algorithm as well as arbitrarily. The control performance of buildings that are equipped and controlled using the PSO algorithm method placement is assessed and compared with arbitrary placement of controllers using both near- and far-field ground motions of Kobe and Chi-Chi earthquakes.

  4. Near-optimal quantum circuit for Grover's unstructured search using a transverse field

    Science.gov (United States)

    Jiang, Zhang; Rieffel, Eleanor G.; Wang, Zhihui

    2017-06-01

    Inspired by a class of algorithms proposed by Farhi et al. (arXiv:1411.4028), namely, the quantum approximate optimization algorithm (QAOA), we present a circuit-based quantum algorithm to search for a needle in a haystack, obtaining the same quadratic speedup achieved by Grover's original algorithm. In our algorithm, the problem Hamiltonian (oracle) and a transverse field are applied alternately to the system in a periodic manner. We introduce a technique, based on spin-coherent states, to analyze the composite unitary in a single period. This composite unitary drives a closed transition between two states that have high degrees of overlap with the initial state and the target state, respectively. The transition rate in our algorithm is of order Θ (1 /√{N }) , and the overlaps are of order Θ (1 ) , yielding a nearly optimal query complexity of T ≃√{N }(π /2 √{2 }) . Our algorithm is a QAOA circuit that demonstrates a quantum advantage with a large number of iterations that is not derived from Trotterization of an adiabatic quantum optimization (AQO) algorithm. It also suggests that the analysis required to understand QAOA circuits involves a very different process from estimating the energy gap of a Hamiltonian in AQO.

  5. The Next Step in Deployment of Computer Based Procedures For Field Workers: Insights And Results From Field Evaluations at Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Oxstrand, Johanna; Le Blanc, Katya L.; Bly, Aaron

    2015-02-01

    The paper-based procedures currently used for nearly all activities in the commercial nuclear power industry have a long history of ensuring safe operation of the plants. However, there is potential to greatly increase efficiency and safety by improving how the human operator interacts with the procedures. One way to achieve these improvements is through the use of computer-based procedures (CBPs). A CBP system offers a vast variety of improvements, such as context driven job aids, integrated human performance tools (e.g., placekeeping, correct component verification, etc.), and dynamic step presentation. The latter means that the CBP system could only display relevant steps based on operating mode, plant status, and the task at hand. A dynamic presentation of the procedure (also known as context-sensitive procedures) will guide the operator down the path of relevant steps based on the current conditions. This feature will reduce the operator’s workload and inherently reduce the risk of incorrectly marking a step as not applicable and the risk of incorrectly performing a step that should be marked as not applicable. The research team at the Idaho National Laboratory has developed a prototype CBP system for field workers, which has been evaluated from a human factors and usability perspective in four laboratory studies. Based on the results from each study revisions were made to the CBP system. However, a crucial step to get the end users' (e.g., auxiliary operators, maintenance technicians, etc.) acceptance is to put the system in their hands and let them use it as a part of their everyday work activities. In the spring 2014 the first field evaluation of the INL CBP system was conducted at a nuclear power plant. Auxiliary operators conduct a functional test of one out of three backup air compressors each week. During the field evaluation activity, one auxiliary operator conducted the test with the paper-based procedure while a second auxiliary operator

  6. Transposition of the 97/43 EURATOM directive. Mission on procedures and standard levels of medical examinations using ionizing radiations. The radiological procedures: quality criteria and doses optimization

    International Nuclear Information System (INIS)

    2001-07-01

    The objective of this report concerns the optimization of radiological practices, to avoid delivering unuseful doses while ensuring an image quality necessary to the obtaining of the desired diagnosis information. (N.C.)

  7. Optimized pre-thinning procedures of ion-beam thinning for TEM sample preparation by magnetorheological polishing.

    Science.gov (United States)

    Luo, Hu; Yin, Shaohui; Zhang, Guanhua; Liu, Chunhui; Tang, Qingchun; Guo, Meijian

    2017-10-01

    Ion-beam-thinning is a well-established sample preparation technique for transmission electron microscopy (TEM), but tedious procedures and labor consuming pre-thinning could seriously reduce its efficiency. In this work, we present a simple pre-thinning technique by using magnetorheological (MR) polishing to replace manual lapping and dimpling, and demonstrate the successful preparation of electron-transparent single crystal silicon samples after MR polishing and single-sided ion milling. Dimples pre-thinned to less than 30 microns and with little mechanical surface damage were repeatedly produced under optimized MR polishing conditions. Samples pre-thinned by both MR polishing and traditional technique were ion-beam thinned from the rear side until perforation, and then observed by optical microscopy and TEM. The results show that the specimen pre-thinned by MR technique was free from dimpling related defects, which were still residual in sample pre-thinned by conventional technique. Nice high-resolution TEM images could be acquired after MR polishing and one side ion-thinning. MR polishing promises to be an adaptable and efficient method for pre-thinning in preparation of TEM specimens, especially for brittle ceramics. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Fabrication of compact and stable perovskite films with optimized precursor composition in the fast-growing procedure

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Tanghao; Zhou, Yuanyuan; Hu, Qin; Chen, Ke; Zhang, Yifei; Yang, Wenqiang; Wu, Jiang; Ye, Fengjun; Luo, Deying; Zhu, Kai; Padture, Nitin P.; Liu, Feng; Russell, Thomas; Zhu, Rui; Gong, Qihuang

    2017-06-02

    The fast-growing procedure (FGP) provides a simple, high-yield and lead (Pb)-release free method to prepare perovskite films. In the FGP, the ultra-dilute perovskite precursor solution is drop-cast onto a hot (~240 degrees C) substrate, where a perovskite film grows immediately accompanied by the rapid evaporation of the host solvent. In this process, all the raw materials in the precursor solution are deposited into the final perovskite film. The potential pollution caused by Pb can be significantly reduced. Properties of the FGP-processed perovskite films can be modulated by the precursor composition. While CH3NH3Cl (MACl) affects the crystallization process and leads to full surface coverage, CH(NH2)2I (FAI) enhances the thermal stability of the film. Based on the optimized precursor composition of PbI2(1-x)FAI xMACl, x=0.75, FGP-processed planar heterojunction perovskite solar cells exhibit power conversion efficiencies (PCEs) exceeding 15% with suppressed hysteresis and excellent reproducibility.

  9. Ab initio protein structure assembly using continuous structure fragments and optimized knowledge-based force field.

    Science.gov (United States)

    Xu, Dong; Zhang, Yang

    2012-07-01

    Ab initio protein folding is one of the major unsolved problems in computational biology owing to the difficulties in force field design and conformational search. We developed a novel program, QUARK, for template-free protein structure prediction. Query sequences are first broken into fragments of 1-20 residues where multiple fragment structures are retrieved at each position from unrelated experimental structures. Full-length structure models are then assembled from fragments using replica-exchange Monte Carlo simulations, which are guided by a composite knowledge-based force field. A number of novel energy terms and Monte Carlo movements are introduced and the particular contributions to enhancing the efficiency of both force field and search engine are analyzed in detail. QUARK prediction procedure is depicted and tested on the structure modeling of 145 nonhomologous proteins. Although no global templates are used and all fragments from experimental structures with template modeling score >0.5 are excluded, QUARK can successfully construct 3D models of correct folds in one-third cases of short proteins up to 100 residues. In the ninth community-wide Critical Assessment of protein Structure Prediction experiment, QUARK server outperformed the second and third best servers by 18 and 47% based on the cumulative Z-score of global distance test-total scores in the FM category. Although ab initio protein folding remains a significant challenge, these data demonstrate new progress toward the solution of the most important problem in the field. Copyright © 2012 Wiley Periodicals, Inc.

  10. Cohesive phase-field fracture and a PDE constrained optimization approach to fracture inverse problems

    Energy Technology Data Exchange (ETDEWEB)

    Tupek, Michael R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-06-30

    In recent years there has been a proliferation of modeling techniques for forward predictions of crack propagation in brittle materials, including: phase-field/gradient damage models, peridynamics, cohesive-zone models, and G/XFEM enrichment techniques. However, progress on the corresponding inverse problems has been relatively lacking. Taking advantage of key features of existing modeling approaches, we propose a parabolic regularization of Barenblatt cohesive models which borrows extensively from previous phase-field and gradient damage formulations. An efficient explicit time integration strategy for this type of nonlocal fracture model is then proposed and justified. In addition, we present a C++ computational framework for computing in- put parameter sensitivities efficiently for explicit dynamic problems using the adjoint method. This capability allows for solving inverse problems involving crack propagation to answer interesting engineering questions such as: 1) what is the optimal design topology and material placement for a heterogeneous structure to maximize fracture resistance, 2) what loads must have been applied to a structure for it to have failed in an observed way, 3) what are the existing cracks in a structure given various experimental observations, etc. In this work, we focus on the first of these engineering questions and demonstrate a capability to automatically and efficiently compute optimal designs intended to minimize crack propagation in structures.

  11. SPEXTRA: Optimal extraction code for long-slit spectra in crowded fields

    Science.gov (United States)

    Sarkisyan, A. N.; Vinokurov, A. S.; Solovieva, Yu. N.; Sholukhova, O. N.; Kostenkov, A. E.; Fabrika, S. N.

    2017-10-01

    We present a code for the optimal extraction of long-slit 2D spectra in crowded stellar fields. Its main advantage and difference from the existing spectrum extraction codes is the presence of a graphical user interface (GUI) and a convenient visualization system of data and extraction parameters. On the whole, the package is designed to study stars in crowded fields of nearby galaxies and star clusters in galaxies. Apart from the spectrum extraction for several stars which are closely located or superimposed, it allows the spectra of objects to be extracted with subtraction of superimposed nebulae of different shapes and different degrees of ionization. The package can also be used to study single stars in the case of a strong background. In the current version, the optimal extraction of 2D spectra with an aperture and the Gaussian function as PSF (point spread function) is proposed. In the future, the package will be supplemented with the possibility to build a PSF based on a Moffat function. We present the details of GUI, illustrate main features of the package, and show results of extraction of the several interesting spectra of objects from different telescopes.

  12. Least Squares Magnetic-Field Optimization for Portable Nuclear Magnetic Resonance Magnet Design

    International Nuclear Information System (INIS)

    Paulsen, Jeffrey L; Franck, John; Demas, Vasiliki; Bouchard, Louis-S.

    2008-01-01

    Single-sided and mobile nuclear magnetic resonance (NMR) sensors have the advantages of portability, low cost, and low power consumption compared to conventional high-field NMR and magnetic resonance imaging (MRI) systems. We present fast, flexible, and easy-to-implement target field algorithms for mobile NMR and MRI magnet design. The optimization finds a global optimum in a cost function that minimizes the error in the target magnetic field in the sense of least squares. When the technique is tested on a ring array of permanent-magnet elements, the solution matches the classical dipole Halbach solution. For a single-sided handheld NMR sensor, the algorithm yields a 640 G field homogeneous to 16,100 ppm across a 1.9 cc volume located 1.5 cm above the top of the magnets and homogeneous to 32,200 ppm over a 7.6 cc volume. This regime is adequate for MRI applications. We demonstrate that the homogeneous region can be continuously moved away from the sensor by rotating magnet rod elements, opening the way for NMR sensors with adjustable 'sensitive volumes'

  13. Procedures for PuO2 field measurements with an HLNC-II

    International Nuclear Information System (INIS)

    Whan, G.A.

    1987-05-01

    An upgraded version of the high-level neutron coincidence counter (HLNC-II) has been designed with faster electronics, higher counting efficiencies, a more uniform counting response within the sample cavity, and improved ruggedness and portability. These procedures describe the assay of PuO 2 powder for plutonium mass using the new HLNC-II along with the JOMAR JSR-11 electronics package, a Hewlett-Packard HP-85B computer, and the CC12 computer program

  14. Technical procedures for ecology: Environmental field program, Deaf Smith County Site, Texas: Final draft

    International Nuclear Information System (INIS)

    1987-08-01

    This volume contains Technical Procedures pursuant to the Land Use Site Study Plan including walkover surveys for threatened, endangered, or candidate species; vegetation classification and mapping; reclamation planning; wetland and floodplain determination and characterization of playas; wildlife habitat mapping methods; mammal sampling; bird survey methods; reptile and amphibian survey methods; preexisting environmental; stress and disturbance studies methods; voucher specimens for plants; and voucher specimens to wildlife. 9 refs., 5 figs., 1 tab

  15. Study on poloidal field coil optimization and equilibrium control of ITER

    International Nuclear Information System (INIS)

    Shinya, Kichiro; Sugihara, Masayoshi; Nishio, Satoshi

    1989-03-01

    The purpose of this report is to present general features of the poloidal field coil optimization for the ITER plasma, flexibility analysis for various plasma options and some other aspect of the equilibrium control which is required for understanding plasma operation in more detail. Double null divertor plasma was selected as a main object of the optimization. Single null divertor plasma was assumed to be an alternative, because single null divertor plasma can be operational within the amounts of the total stored energy and ampere-turns of the double null divertor plasma, if it is shaped appropriately. Plasma parameters used in the present analysis are mainly those employed in the preliminary study by the Basic Device Engineering group of the ITER design team. The most part of the optimization study, however, utilizes the parameters proposed for discussion by the Japan team before starting joint design work at Garching. Plasma shape, and solenoid coil shape and size, which maximize available flux swing with reasonable amounts of the stored energy and ampere-turns, are discussed. Location and minimum number of the poloidal field coils with adequate shaping controllability were also discussed for various plasma options. Some other aspect of the equilibrium control, such as separatrix swing, moving null point operation during plasma heating and possible range of li, were evaluated and the guideline for the engineering design was proposed. Finally, fusion power output was estimated for the different pressure profiles and combinations of the average density and temperature, and the magnetic quantities of the scrape-off region was calculated to be available for the future divertor analysis. (author)

  16. Arsenic and iron removal from groundwater by oxidation–coagulation at optimized pH: Laboratory and field studies

    Energy Technology Data Exchange (ETDEWEB)

    Bordoloi, Shreemoyee; Nath, Suresh K.; Gogoi, Sweety; Dutta, Robin K., E-mail: robind@tezu.ernet.in

    2013-09-15

    Highlights: • Arsenic and iron removed by a systematic oxidation–coagulation at optimized pH. • Used KMnO{sub 4} as oxidant and FeCl{sub 3} as coagulant in presence of NaHCO{sub 3}. • Field trial results are highly encouraging. • The method is efficient, safe, simple and low-cost. • The method is suitable for rural application in developing countries. -- Abstract: A three-step treatment process involving (i) mild alkaline pH-conditioning by NaHCO{sub 3}; (ii) oxidation of arsenite and ferrous ions by KMnO{sub 4}, itself precipitating as insoluble MnO{sub 2} under the pH condition; and (iii) coagulation by FeCl{sub 3} has been used for simultaneous removal of arsenic and iron ions from water. The treated water is filtered after a residence time of 1–2 h. Laboratory batch experiments were performed to optimize the doses. A field trial was performed with an optimized recipe at 30 households and 5 schools at some highly arsenic affected villages in Assam, India. Simultaneous removals of arsenic from initial 0.1–0.5 mg/L to about 5 μg/L and iron from initial 0.3–5.0 mg/L to less than 0.1 mg/L have been achieved along with final pH between 7.0 and 7.5 after residence time of 1 h. The process also removes other heavy elements, if present, without leaving any additional toxic residue. The small quantity of solid sludge containing mainly ferrihydrite with adsorbed arsenate passes the toxicity characteristic leaching procedure (TCLP) test. The estimated recurring cost is approximately USD 0.16 per/m{sup 3} of purified water. A high efficiency, an extremely low cost, safety, non-requirement of power and simplicity of operation make the technique potential for rural application.

  17. Efficient 3D porous microstructure reconstruction via Gaussian random field and hybrid optimization.

    Science.gov (United States)

    Jiang, Z; Chen, W; Burkhart, C

    2013-11-01

    Obtaining an accurate three-dimensional (3D) structure of a porous microstructure is important for assessing the material properties based on finite element analysis. Whereas directly obtaining 3D images of the microstructure is impractical under many circumstances, two sets of methods have been developed in literature to generate (reconstruct) 3D microstructure from its 2D images: one characterizes the microstructure based on certain statistical descriptors, typically two-point correlation function and cluster correlation function, and then performs an optimization process to build a 3D structure that matches those statistical descriptors; the other method models the microstructure using stochastic models like a Gaussian random field and generates a 3D structure directly from the function. The former obtains a relatively accurate 3D microstructure, but computationally the optimization process can be very intensive, especially for problems with large image size; the latter generates a 3D microstructure quickly but sacrifices the accuracy due to issues in numerical implementations. A hybrid optimization approach of modelling the 3D porous microstructure of random isotropic two-phase materials is proposed in this paper, which combines the two sets of methods and hence maintains the accuracy of the correlation-based method with improved efficiency. The proposed technique is verified for 3D reconstructions based on silica polymer composite images with different volume fractions. A comparison of the reconstructed microstructures and the optimization histories for both the original correlation-based method and our hybrid approach demonstrates the improved efficiency of the approach. © 2013 The Authors Journal of Microscopy © 2013 Royal Microscopical Society.

  18. Feasibility and acceptability of the DSM-5 Field Trial procedures in the Johns Hopkins Community Psychiatry Programs.

    Science.gov (United States)

    Clarke, Diana E; Wilcox, Holly C; Miller, Leslie; Cullen, Bernadette; Gerring, Joan; Greiner, Lisa H; Newcomer, Alison; McKitty, Mellisha V; Regier, Darrel A; Narrow, William E

    2014-06-01

    The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) contains criteria for psychiatric diagnoses that reflect advances in the science and conceptualization of mental disorders and address the needs of clinicians. DSM-5 also recommends research on dimensional measures of cross-cutting symptoms and diagnostic severity, which are expected to better capture patients' experiences with mental disorders. Prior to its May 2013 release, the American Psychiatric Association (APA) conducted field trials to examine the feasibility, clinical utility, reliability, and where possible, the validity of proposed DSM-5 diagnostic criteria and dimensional measures. The methods and measures proposed for the DSM-5 field trials were pilot tested in adult and child/adolescent clinical samples, with the goal to identify and correct design and procedural problems with the proposed methods before resources were expended for the larger DSM-5 Field Trials. Results allowed for the refinement of the protocols, procedures, and measures, which facilitated recruitment, implementation, and completion of the DSM-5 Field Trials. These results highlight the benefits of pilot studies in planning large multisite studies. Copyright © 2013, American Psychiatric Association. All rights reserved.

  19. Feasibility and acceptability of the DSM-5 Field Trial procedures in the Johns Hopkins Community Psychiatry Programs†

    Science.gov (United States)

    Clarke, Diana E.; Wilcox, Holly C.; Miller, Leslie; Cullen, Bernadette; Gerring, Joan; Greiner, Lisa H.; Newcomer, Alison; Mckitty, Mellisha V.; Regier, Darrel A.; Narrow, William E.

    2014-01-01

    The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) contains criteria for psychiatric diagnoses that reflect advances in the science and conceptualization of mental disorders and address the needs of clinicians. DSM-5 also recommends research on dimensional measures of cross-cutting symptoms and diagnostic severity, which are expected to better capture patients’ experiences with mental disorders. Prior to its May 2013 release, the American Psychiatric Association (APA) conducted field trials to examine the feasibility, clinical utility, reliability, and where possible, the validity of proposed DSM-5 diagnostic criteria and dimensional measures. The methods and measures proposed for the DSM-5 field trials were pilot tested in adult and child/adolescent clinical samples, with the goal to identify and correct design and procedural problems with the proposed methods before resources were expended for the larger DSM-5 Field Trials. Results allowed for the refinement of the protocols, procedures, and measures, which facilitated recruitment, implementation, and completion of the DSM-5 Field Trials. These results highlight the benefits of pilot studies in planning large multisite studies. PMID:24615761

  20. Time-optimal path planning in uncertain flow fields using ensemble method

    KAUST Repository

    Wang, Tong

    2016-01-06

    An ensemble-based approach is developed to conduct time-optimal path planning in unsteady ocean currents under uncertainty. We focus our attention on two-dimensional steady and unsteady uncertain flows, and adopt a sampling methodology that is well suited to operational forecasts, where a set deterministic predictions is used to model and quantify uncertainty in the predictions. In the operational setting, much about dynamics, topography and forcing of the ocean environment is uncertain, and as a result a single path produced by a model simulation has limited utility. To overcome this limitation, we rely on a finitesize ensemble of deterministic forecasts to quantify the impact of variability in the dynamics. The uncertainty of flow field is parametrized using a finite number of independent canonical random variables with known densities, and the ensemble is generated by sampling these variables. For each the resulting realizations of the uncertain current field, we predict the optimal path by solving a boundary value problem (BVP), based on the Pontryagin maximum principle. A family of backward-in-time trajectories starting at the end position is used to generate suitable initial values for the BVP solver. This allows us to examine and analyze the performance of sampling strategy, and develop insight into extensions dealing with regional or general circulation models. In particular, the ensemble method enables us to perform a statistical analysis of travel times, and consequently develop a path planning approach that accounts for these statistics. The proposed methodology is tested for a number of scenarios. We first validate our algorithms by reproducing simple canonical solutions, and then demonstrate our approach in more complex flow fields, including idealized, steady and unsteady double-gyre flows.

  1. A Microwave Holographic Procedure for Large Symmetric Reflector Antennas Using a Fresnel-Zone Field Data Processing

    Directory of Open Access Journals (Sweden)

    Giuseppe Mazzarella

    2012-01-01

    Full Text Available In this paper we propose a new holographic procedure for the diagnostic of large reflector antennas, based on the direct use of the Fresnel-field pattern. The relation leading from the Fresnel field to the current on the reflector surface is formulated in the least-squares sense as a discrete data inverse problem and then regularized by using a singular value decomposition approach. A detailed theoretical analysis of the problem and full assessment of the presented technique are provided. Simulations are carried out by using the radiative near-field pattern generated with a commercial software. Results show good accuracy and robustness to noise for the retrieval of the panel-to-panel misalignment of a reflector antenna.

  2. Correction: General optimization procedure towards the design of a new family of minimal parameter spin-component-scaled double-hybrid density functional theory.

    Science.gov (United States)

    Roch, Loïc M; Baldridge, Kim K

    2018-02-07

    Correction for 'General optimization procedure towards the design of a new family of minimal parameter spin-component-scaled double-hybrid density functional theory' by Loïc M. Roch and Kim K. Baldridge, Phys. Chem. Chem. Phys., 2017, 19, 26191-26200.

  3. Transcranial Magnetic Stimulation: An Automated Procedure to Obtain Coil-specific Models for Field Calculations

    DEFF Research Database (Denmark)

    Madsen, Kristoffer Hougaard; Ewald, Lars; Siebner, Hartwig R.

    2015-01-01

    Background: Field calculations for transcranial magnetic stimulation (TMS) are increasingly implemented online in neuronavigation systems and in more realistic offline approaches based on finite-element methods. They are often based on simplified and/or non-validated models of the magnetic vector...... potential of the TMS coils. Objective: To develop an approach to reconstruct the magnetic vector potential based on automated measurements. Methods: We implemented a setup that simultaneously measures the three components of the magnetic field with high spatial resolution. This is complemented by a novel...... approach to determine the magnetic vector potential via volume integration of the measured field. Results: The integration approach reproduces the vector potential with very good accuracy. The vector potential distribution of a standard figure-of-eight shaped coil determined with our setup corresponds well...

  4. Momentum reconstruction procedure for a nonfocusing spectrometer with wide-aperture analyzing magnet and nonuniform field

    International Nuclear Information System (INIS)

    Azhgirej, L.S.; Malinina, L.V.; Strokovskij, E.A.; Augustyniak, W.; Farhi, L.; Kunne, R.A.

    1999-01-01

    The SPES-4 spectrometer at SATURNE II has recently been equipped with a detection system working in coincidence with it. This system uses a wide-aperture dipole magnet. A method is described to determine the momentum vector and interaction vertex of the detected charged particle from its trajectory parameters measured outside the inhomogeneous field of the magnet. The feature of the set-up is that all detectors are placed outside the dipole field, while the target is inside the ∼ 1 T field and the incoming track is not measured. The feature of the method is that it is simple and fast, while it uses only the straight line part of the particle trajectory, which can be measured with sufficient accuracy

  5. Arsenic and iron removal from groundwater by oxidation-coagulation at optimized pH: laboratory and field studies.

    Science.gov (United States)

    Bordoloi, Shreemoyee; Nath, Suresh K; Gogoi, Sweety; Dutta, Robin K

    2013-09-15

    A three-step treatment process involving (i) mild alkaline pH-conditioning by NaHCO₃; (ii) oxidation of arsenite and ferrous ions by KMnO₄, itself precipitating as insoluble MnO₂ under the pH condition; and (iii) coagulation by FeCl₃ has been used for simultaneous removal of arsenic and iron ions from water. The treated water is filtered after a residence time of 1-2 h. Laboratory batch experiments were performed to optimize the doses. A field trial was performed with an optimized recipe at 30 households and 5 schools at some highly arsenic affected villages in Assam, India. Simultaneous removals of arsenic from initial 0.1-0.5 mg/L to about 5 μg/L and iron from initial 0.3-5.0 mg/L to less than 0.1 mg/L have been achieved along with final pH between 7.0 and 7.5 after residence time of 1h. The process also removes other heavy elements, if present, without leaving any additional toxic residue. The small quantity of solid sludge containing mainly ferrihydrite with adsorbed arsenate passes the toxicity characteristic leaching procedure (TCLP) test. The estimated recurring cost is approximately USD 0.16 per/m(3) of purified water. A high efficiency, an extremely low cost, safety, non-requirement of power and simplicity of operation make the technique potential for rural application. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Coulomb interactions between cytoplasmic electric fields and phosphorylated messenger proteins optimize information flow in cells.

    Directory of Open Access Journals (Sweden)

    Robert A Gatenby

    2010-08-01

    proteins and intracellular electric fields will optimize information transfer from the CM to the NM in cells.

  7. Tuning and optimization of the field distribution for 4-rod Radio Frequency Quadrupole linacs

    International Nuclear Information System (INIS)

    Schmidt, Janet Susan

    2014-01-01

    In this thesis, the tuning process of the 4-rod Radio Frequency Quadrupole has been analyzed and a theory for the prediction of the tuning plate's influence on the longitudinal voltage distribution was developed together with RF design options for the optimization of the fringe fields. The basic principles of the RFQ's particle dynamics and resonant behavior are introduced in the theory part of this thesis. All studies that are presented are based on the work on four RFQs of recent linac projects. These RFQs are described in one chapter. Here, the projects are introduced together with details about the RFQ parameters and performance. In the meantime two of these RFQs are in full operation at NSCL at MSU and FNAL. One is operating in the test phase of the MedAustron Cancer Therapy Center and the fourth one for LANL is about to be built. The longitudinal voltage distribution has been studied in detail with a focus on the influence of the RF design with tuning elements and parameters like the electrodes overlap or the distance between stems. The theory for simulation methods for the field flatness that were developed as part of this thesis, as well as its simulation with CST MWS have been analyzed and compared to measurements. The lumped circuit model has proven to predict results with an accuracy that can be used in the tuning process of 4-rod RFQs. Together with results from the tuning studies, the studies on the fringe fields of the 4-rod structure lead to a proposal for a 4-rod RFQ model with an improved field distribution in the transverse and longitudinal electric field.

  8. A neutron spin echo spectrometer with two optimal field shape coils for neutron spin precession

    International Nuclear Information System (INIS)

    Takeda, T.; Ebisawa, T.; Tasaki, S.; Ito, Y.; Takahashi, S.; Yoshizawa, H.

    1995-01-01

    We have designed and have been constructing at the C 2-2 cold neutron guide port of JRR-3M, JAERI, a neutron spin echo spectrometer (NSE) which is equipped with two optimal field shape (OFS) coils for neutron spin precession with the maximum field integral of 0.22 T m, an assembly of position sensitive detectors (PSD), a converging polarizer and a wide area analyzer. The dynamic range of scattering vector Q covers from 0.005 A -1 to 0.2 A -1 and that of energy hω from 10 neV to 30 μeV. Performance tests of the OFS coils show that the inhomogeneity of the magnetic field integral in the OFS coils with the spiral coils is so small that the NSE signal amplitude decreases little even for the neutron cross section of 30 mm diameter as the Fourier time t increases up to 25 ns, though the precession coils are close to iron covers of the neighboring neutron guide. This verifies that the OFS precession coils are appropriate for this NSE spectrometer. Another test experiment shows that the homogeneity condition of the precession magnet is loosened by use of PSD. (orig.)

  9. Inspection Regulation between General Procedural Codification and Field Specifics – a Case Study of Slovenia

    Directory of Open Access Journals (Sweden)

    Kovač Polonca

    2016-03-01

    Full Text Available Inspection, as the authoritative supervision of private liable persons to comply their activities with sector-specific laws, should ensure the full implementation of public policies. Slovenia adopted the Inspection Act (IA in 2002, in order to conduct efficient inspection, and simultaneously guarantee the defence rights of the supervised parties pursuant to the fundamental principles of the EU, the national Constitution, and general Administrative Procedure Act. This article addresses the search for a balance between general codification and sector-related specifics as stipulated by the IA, applying normative, constitutional case law and comparative methods. Special attention is dedicated to the IA rules regarding participants, their legal protection and stages of respective proceedings. It has been concluded that the most of the IA specifics are justified in order to efficiently serve the public interest. This study reveals that the Slovene IA can represent a role model for efficient yet democratic supervision in other MS as well.

  10. Optimization of Plastic Scintillator Thicknesses for Online Beta Detection in Mixed Fields

    Energy Technology Data Exchange (ETDEWEB)

    Pourtangestani, K.; Machrafi, R. [University of Ontario Institute of Technology, Oshawa, ON (Canada)

    2013-07-15

    For efficient beta detection in a mixed beta-gamma field, Monte Carlo simulation models have been developed to optimize the thickness of a plastic scintillator used in whole body monitor. The simulation has been performed using MCNP/X code and different thicknesses of plastic scintillators ranging from 150 to 600 {mu}m have been used. The relationship between the thickness of the scintillator and the efficiency of the detector has been analysed. For 150 {mu}m thickness, an experimental investigation has been conducted with different beta sources at different positions on the scintillator and the counting efficiency of the unit has been measured. Evaluated data along with experimental ones have been discussed. A thickness of 300 {mu}m to 500 {mu}m has been found to be an optimum thickness for better beta detection efficiency in the presence of low energy gamma ray. (author)

  11. φq-field theory for portfolio optimization: “fat tails” and nonlinear correlations

    Science.gov (United States)

    Sornette, D.; Simonetti, P.; Andersen, J. V.

    2000-08-01

    Physics and finance are both fundamentally based on the theory of random walks (and their generalizations to higher dimensions) and on the collective behavior of large numbers of correlated variables. The archetype examplifying this situation in finance is the portfolio optimization problem in which one desires to diversify on a set of possibly dependent assets to optimize the return and minimize the risks. The standard mean-variance solution introduced by Markovitz and its subsequent developments is basically a mean-field Gaussian solution. It has severe limitations for practical applications due to the strongly non-Gaussian structure of distributions and the nonlinear dependence between assets. Here, we present in details a general analytical characterization of the distribution of returns for a portfolio constituted of assets whose returns are described by an arbitrary joint multivariate distribution. In this goal, we introduce a non-linear transformation that maps the returns onto Gaussian variables whose covariance matrix provides a new measure of dependence between the non-normal returns, generalizing the covariance matrix into a nonlinear covariance matrix. This nonlinear covariance matrix is chiseled to the specific fat tail structure of the underlying marginal distributions, thus ensuring stability and good conditioning. The portfolio distribution is then obtained as the solution of a mapping to a so-called φq field theory in particle physics, of which we offer an extensive treatment using Feynman diagrammatic techniques and large deviation theory, that we illustrate in details for multivariate Weibull distributions. The interaction (non-mean field) structure in this field theory is a direct consequence of the non-Gaussian nature of the distribution of asset price returns. We find that minimizing the portfolio variance (i.e. the relatively “small” risks) may often increase the large risks, as measured by higher normalized cumulants. Extensive

  12. Optimal likelihood-based matching of volcanic sources and deposits in the Auckland Volcanic Field

    Science.gov (United States)

    Kawabata, Emily; Bebbington, Mark S.; Cronin, Shane J.; Wang, Ting

    2016-09-01

    In monogenetic volcanic fields, where each eruption forms a new volcano, focusing and migration of activity over time is a very real possibility. In order for hazard estimates to reflect future, rather than past, behavior, it is vital to assemble as much reliable age data as possible on past eruptions. Multiple swamp/lake records have been extracted from the Auckland Volcanic Field, underlying the 1.4 million-population city of Auckland. We examine here the problem of matching these dated deposits to the volcanoes that produced them. The simplest issue is separation in time, which is handled by simulating prior volcano age sequences from direct dates where known, thinned via ordering constraints between the volcanoes. The subproblem of varying deposition thicknesses (which may be zero) at five locations of known distance and azimuth is quantified using a statistical attenuation model for the volcanic ash thickness. These elements are combined with other constraints, from widespread fingerprinted ash layers that separate eruptions and time-censoring of the records, into a likelihood that was optimized via linear programming. A second linear program was used to optimize over the Monte-Carlo simulated set of prior age profiles to determine the best overall match and consequent volcano age assignments. Considering all 20 matches, and the multiple factors of age, direction, and size/distance simultaneously, results in some non-intuitive assignments which would not be produced by single factor analyses. Compared with earlier work, the results provide better age control on a number of smaller centers such as Little Rangitoto, Otuataua, Taylors Hill, Wiri Mountain, Green Hill, Otara Hill, Hampton Park and Mt Cambria. Spatio-temporal hazard estimates are updated on the basis of the new ordering, which suggest that the scale of the 'flare-up' around 30 ka, while still highly significant, was less than previously thought.

  13. SpecOp: Optimal Extraction Software for Integral Field Unit Spectrographs

    Science.gov (United States)

    McCarron, Adam; Ciardullo, Robin; Eracleous, Michael

    2018-01-01

    The Hobby-Eberly Telescope’s new low resolution integral field spectrographs, LRS2-B and LRS2-R, each cover a 12”x6” area on the sky with 280 fibers and generate spectra with resolutions between R=1100 and R=1900. To extract 1-D spectra from the instrument’s 3D data cubes, a program is needed that is flexible enough to work for a wide variety of targets, including continuum point sources, emission line sources, and compact sources embedded in complex backgrounds. We therefore introduce SpecOp, a user-friendly python program for optimally extracting spectra from integral-field unit spectrographs. As input, SpecOp takes a sky-subtracted data cube consisting of images at each wavelength increment set by the instrument’s spectral resolution, and an error file for each count measurement. All of these files are generated by the current LRS2 reduction pipeline. The program then collapses the cube in the image plane using the optimal extraction algorithm detailed by Keith Horne (1986). The various user-selected options include the fraction of the total signal enclosed in a contour-defined region, the wavelength range to analyze, and the precision of the spatial profile calculation. SpecOp can output the weighted counts and errors at each wavelength in various table formats using python’s astropy package. We outline the algorithm used for extraction and explain how the software can be used to easily obtain high-quality 1-D spectra. We demonstrate the utility of the program by applying it to spectra of a variety of quasars and AGNs. In some of these targets, we extract the spectrum of a nuclear point source that is superposed on a spatially extended galaxy.

  14. Analysis of Radiation Field and Block Pattern for Optimal Size in Multileaf Collimator

    International Nuclear Information System (INIS)

    Ahn, Seoung Do; Yang, Kwang Mo; Yi, Byong Yong; Choi, Eun Kyong; Chang, Hye Sook

    1994-01-01

    The patterns of the conventional radiation treatment fields and their shielding blocks are analysed to determine the optimal dimension of the MultiLeaf Collimator (MLC) which is considered as an essential tool for conformal therapy. Total 1169 radiation fields from 303 patients (203 from Asan Medical center, 50 from Baek Hosp and 50 from Hanyang Univ. Hosp.) were analysed for this study. Weighted case selection treatment site (from The Korean Society of Therapeutic Radiology 1003). Ninety one percent of total fields have shielding blocks. Y axis is defined as leaf movement direction and it is assumed that MLC is installed on the cranial-caudal direction. The length of X axis were distributed from 4cm to 40cm (less than 21cm for 95% of cases), and Y axis from 5cm to 38cm (less than 22cm for 95% of cases). The shielding blocks extended to less than 6cm from center of the filed for 95% of the cases. Start length for ninety five percent of block is less than 10cm for X axis and 11cm for Y axis. Seventy six percent of shielding blocks could be placed by either X or Y axis direction, 7.9% only by Y axis, 5.1% only by X axis and it is reasonable to install MLC for Y direction. Ninety five percent of patients can be treated with coplanar rotation therapy without changing the collimator angle. Eleven percent of cases of cases were impossible to replace with MLC. Futher study of shielding should be larger than 21cm X 22cm. The MLC should be designed as a pair of 21 leaves with 1cm wide for an acceptable resolution and 17cm long to enable the leaf to overtravel at least 6cm from the treatment field center

  15. Optimizing Solute-Solute Interactions in the GLYCAM06 and CHARMM36 Carbohydrate Force Fields Using Osmotic Pressure Measurements.

    Science.gov (United States)

    Lay, Wesley K; Miller, Mark S; Elcock, Adrian H

    2016-04-12

    GLYCAM06 and CHARMM36 are successful force fields for modeling carbohydrates. To correct recently identified deficiencies with both force fields, we adjusted intersolute nonbonded parameters to reproduce the experimental osmotic coefficient of glucose at 1 M. The modified parameters improve behavior of glucose and sucrose up to 4 M and improve modeling of a dextran 55-mer. While the modified parameters may not be applicable to all carbohydrates, they highlight the use of osmotic simulations to optimize force fields.

  16. Optimization of instrumental neutron activation analysis method by means of 2k experimental design technique aiming the validation of analytical procedures

    International Nuclear Information System (INIS)

    Petroni, Robson; Moreira, Edson G.

    2013-01-01

    In this study optimization of procedures and standardization of Instrumental Neutron Activation Analysis (INAA) methods were carried out for the determination of the elements arsenic, chromium, cobalt, iron, rubidium, scandium, selenium and zinc in biological materials. The aim is to validate the analytical methods for future accreditation at the National Institute of Metrology, Quality and Technology (INMETRO). The 2 k experimental design was applied for evaluation of the individual contribution of selected variables of the analytical procedure in the final mass fraction result. Samples of Mussel Tissue Certified Reference Material and multi-element standards were analyzed considering the following variables: sample decay time, counting time and sample distance to detector. The standard multi-element concentration (comparator standard), mass of the sample and irradiation time were maintained constant in this procedure. By means of the statistical analysis and theoretical and experimental considerations it was determined the optimized experimental conditions for the analytical methods that will be adopted for the validation procedure of INAA methods in the Neutron Activation Analysis Laboratory (LAN) of the Research Reactor Center (CRPq) at the Nuclear and Energy Research Institute (IPEN - CNEN/SP). Optimized conditions were estimated based on the results of z-score tests, main effect and interaction effects. The results obtained with the different experimental configurations were evaluated for accuracy (precision and trueness) for each measurement. (author)

  17. Optimization of instrumental neutron activation analysis method by means of 2{sup k} experimental design technique aiming the validation of analytical procedures

    Energy Technology Data Exchange (ETDEWEB)

    Petroni, Robson; Moreira, Edson G., E-mail: rpetroni@ipen.br, E-mail: emoreira@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    In this study optimization of procedures and standardization of Instrumental Neutron Activation Analysis (INAA) methods were carried out for the determination of the elements arsenic, chromium, cobalt, iron, rubidium, scandium, selenium and zinc in biological materials. The aim is to validate the analytical methods for future accreditation at the National Institute of Metrology, Quality and Technology (INMETRO). The 2{sup k} experimental design was applied for evaluation of the individual contribution of selected variables of the analytical procedure in the final mass fraction result. Samples of Mussel Tissue Certified Reference Material and multi-element standards were analyzed considering the following variables: sample decay time, counting time and sample distance to detector. The standard multi-element concentration (comparator standard), mass of the sample and irradiation time were maintained constant in this procedure. By means of the statistical analysis and theoretical and experimental considerations it was determined the optimized experimental conditions for the analytical methods that will be adopted for the validation procedure of INAA methods in the Neutron Activation Analysis Laboratory (LAN) of the Research Reactor Center (CRPq) at the Nuclear and Energy Research Institute (IPEN - CNEN/SP). Optimized conditions were estimated based on the results of z-score tests, main effect and interaction effects. The results obtained with the different experimental configurations were evaluated for accuracy (precision and trueness) for each measurement. (author)

  18. VAS operational procedures and results at the Kansas City Satellite Field Services Station

    Science.gov (United States)

    Heckman, B.; Carle, W.; Anthony, R.

    1983-01-01

    An operational assessment of VAS data by using a Man-computer Interactive Data Access System (McIDAS) terminal linked by a 9600 band telephone line is discussed. Seven hours of VAS data were processed and edited daily. Data was scheduled 16 hours a day, 7 days a week; however, during this time period there were very few days with 16 hours of data to evalute. The McIDAS terminal, which has 10 display frames and 5 graphics, provide access to the sounding data processed. These data are processed using two procedures. The dwell sounding data are generated by using all 12 spectral channels with a spin budget of 39. To provide coverage for most of the United States, soundings are made starting at 18 minutes after the hour from approximately 49 deg N to 36 deg N and at 48 minutes after the hour from 36 deg N to 26 deg N. The dwell imaging mode uses 11 channels but the spin budge is 17. With the reduced spin budget, retrievals can be made at 18 or 48 minutes after the hour for approximately 44 deg N to 27 deg N. With these constraints a schedule, of data sets was proposed to use the schedule and how the data set could be used are shown.

  19. Dose distribution over the radiation field and organs of the body during radiotherapy procedures

    International Nuclear Information System (INIS)

    Roy, S.; Begum, M.; Ambia, A.S.M.; Akhter, S.; Banu, H.

    2001-01-01

    Beam profile of the 60 Co teletherapy unit for 10 cm x 10 cm along central axis was measured to study the symmetry of the gamma beam and found that the average dose was 98.44±1.40 mGy. Output dose versus field size was also measured and values were found reasonable. Dose prescription to delivery was measured by placing TLD onto the treatment field for lung and cervix cancer patient which was found to be 39.16±2.98 Gy and 50.48±3.68 Gy respectively which are within 2 % and 0.17 % of the prescribed dose as 40.00 and 50.40 Gy respectively, reveals good agreement with the treatment planning. Six typical types of patients (both male and female) with cancers in lung, larynx, breast, cervix, oesophagus and brain treated with 60 Co teletherapy were particularly considered for dose assessment at different critical organs of interest. It was observed that the doses to the lens of eye with a maximum value of 460.35+78.87 mGy for a larynx cancer patient to a minimum value of 30.80+4.00 mGy of a cervix cancer patient. Doses to the gonad vary with a maximum value of 3810.80+389.76 mGy for a cervix cancer patient to a minimum value of 8.20+1.00 mGy for a brain cancer patient. (author)

  20. Optimization of potential field method parameters through networks for swarm cooperative manipulation tasks

    Directory of Open Access Journals (Sweden)

    Rocco Furferi

    2016-10-01

    Full Text Available An interesting current research field related to autonomous robots is mobile manipulation performed by cooperating robots (in terrestrial, aerial and underwater environments. Focusing on the underwater scenario, cooperative manipulation of Intervention-Autonomous Underwater Vehicles (I-AUVs is a complex and difficult application compared with the terrestrial or aerial ones because of many technical issues, such as underwater localization and limited communication. A decentralized approach for cooperative mobile manipulation of I-AUVs based on Artificial Neural Networks (ANNs is proposed in this article. This strategy exploits the potential field method; a multi-layer control structure is developed to manage the coordination of the swarm, the guidance and navigation of I-AUVs and the manipulation task. In the article, this new strategy has been implemented in the simulation environment, simulating the transportation of an object. This object is moved along a desired trajectory in an unknown environment and it is transported by four underwater mobile robots, each one provided with a seven-degrees-of-freedom robotic arm. The simulation results are optimized thanks to the ANNs used for the potentials tuning.

  1. Optimization of field homogeneity of Helmholtz-like coils for measuring the balance of planar gradiometers

    International Nuclear Information System (INIS)

    Nordahn, M.A.; Holst, T.; Shen, Y.Q.

    1999-01-01

    Measuring the balance of planar SQUID gradiometers using a relatively small Helmholtz-like coil system requires a careful design of the coils in order to have a high degree of field uniformity along the radial direction. The level to which planar gradiometers can be balanced will be affected by any misalignment of the gradiometer relative to the ideal central position. Therefore, the maximum degree of balancing possible is calculated numerically for the Helmholtz geometry under various perturbations, including misalignment of the gradiometer along the cylindrical and the radial axis, and angular tilting relative to the normal plane. Furthermore, if the ratio between the coil separation and coil radius is chosen to be less than unity, calculations show that the expected radial uniformity of the field can be improved considerably compared to the traditional Helmholtz geometry. The optimized coil geometry is compared to the Helmholtz geometry and is found to yield up to an order of magnitude improvement of the worst case error signal within a volume spanned by the uncertainty in the alignment. (author)

  2. Optimal path-finding through mental exploration based on neural energy field gradients.

    Science.gov (United States)

    Wang, Yihong; Wang, Rubin; Zhu, Yating

    2017-02-01

    Rodent animal can accomplish self-locating and path-finding task by forming a cognitive map in the hippocampus representing the environment. In the classical model of the cognitive map, the system (artificial animal) needs large amounts of physical exploration to study spatial environment to solve path-finding problems, which costs too much time and energy. Although Hopfield's mental exploration model makes up for the deficiency mentioned above, the path is still not efficient enough. Moreover, his model mainly focused on the artificial neural network, and clear physiological meanings has not been addressed. In this work, based on the concept of mental exploration, neural energy coding theory has been applied to the novel calculation model to solve the path-finding problem. Energy field is constructed on the basis of the firing power of place cell clusters, and the energy field gradient can be used in mental exploration to solve path-finding problems. The study shows that the new mental exploration model can efficiently find the optimal path, and present the learning process with biophysical meaning as well. We also analyzed the parameters of the model which affect the path efficiency. This new idea verifies the importance of place cell and synapse in spatial memory and proves that energy coding is effective to study cognitive activities. This may provide the theoretical basis for the neural dynamics mechanism of spatial memory.

  3. Simulation of body force field effects on airfoil separation control and optimization of plasma actuator

    International Nuclear Information System (INIS)

    Abdoli, A; Mirzaee, I; Purmahmod, N; Anvari, A

    2008-01-01

    Among all active flow control methods, EHD, MHD and EMHD are the only methods which operate on the basis of body force induction on flow field. The EHD plasma actuator is the proper method which has been used in various flow control applications recently. In this paper, the effects of different body force fields on different domains have been studied for separation control on NACA 0021 and the results have been discussed. The airflow velocity has been assumed to be 35 m s -1 at a post-stall angle of attack of 23 deg. Three different domains have been used around the airfoil to investigate body forces with different strengths and directions and those which give the best result in separation control have been obtained for each domain. It has been shown that the results could be used for optimizing the plasma actuator by manipulating its electrode configuration. Two non-dimensional numbers, A b and D c , have been obtained and validated by different applied body forces. These numbers have been defined for plasma actuators to show their efficiency in different applications

  4. Simulation of body force field effects on airfoil separation control and optimization of plasma actuator

    Energy Technology Data Exchange (ETDEWEB)

    Abdoli, A; Mirzaee, I; Purmahmod, N [Faculty of Engineering, Urmia University, Urmia (Iran, Islamic Republic of); Anvari, A [Department of Physics, Sharif University of Technology, Tehran (Iran, Islamic Republic of)], E-mail: ab.abdoli@gmail.com

    2008-09-07

    Among all active flow control methods, EHD, MHD and EMHD are the only methods which operate on the basis of body force induction on flow field. The EHD plasma actuator is the proper method which has been used in various flow control applications recently. In this paper, the effects of different body force fields on different domains have been studied for separation control on NACA 0021 and the results have been discussed. The airflow velocity has been assumed to be 35 m s{sup -1} at a post-stall angle of attack of 23 deg. Three different domains have been used around the airfoil to investigate body forces with different strengths and directions and those which give the best result in separation control have been obtained for each domain. It has been shown that the results could be used for optimizing the plasma actuator by manipulating its electrode configuration. Two non-dimensional numbers, A{sub b} and D{sub c}, have been obtained and validated by different applied body forces. These numbers have been defined for plasma actuators to show their efficiency in different applications.

  5. WinFood data from Kenya and Cambodia: Constraints on field procedures

    International Nuclear Information System (INIS)

    Owino, Victor; Omollo, Selina; Konyole, Silvenus; Skau, Jutta; Roos, Nanna; Friis, Henrik; Michaelsen, Kim

    2014-01-01

    issues with the locally produced Winfood product hence ethics approval was delayed. Regarding D2O in Kenya we observed that both ERC and mothers misunderstood the concept of ‘special water’ and it took a long time to explain. In Cambodia mothers were worried about lengthy waiting time for saliva sampling. D2O spillage during dosing was a major problem in Kenya due to agitated children, mainly at 15 months who spat deuterium. High morbidity among children depicted as dehydration limited saliva production while mouth sores made saliva sampling difficult (saliva samples were contaminated with mucus, blood and breast milk). Blood assay challenges included high rates of hemolysis due to restless children and inexperienced staff since procedures are not routine. Nervous mothers made the situation worse. Lack of local facilities to measure iron, zinc status and lipid profile increased cost and delayed results. Conclusions: Challenges were largely contextual. Misconceptions about intervention and procedures, infant morbidity and restlessness affected D2O assessment. Inexperienced staff and lack of local sample analysis capacity affected blood assays. Local laboratory capacity, training of staff and sensitization of communities and ERC are highly recommended. (author)

  6. Requirements for Computer Based-Procedures for Nuclear Power Plant Field Operators. Results from a Qualitative Study

    International Nuclear Information System (INIS)

    Le Blanc, Katya; Oxstrand, J.H.; Waicosky, T.

    2012-01-01

    Although computer-based procedures (CBPs) have been investigated as a way to enhance operator performance on procedural tasks in the nuclear industry for almost thirty years, they are not currently widely deployed at United States utilities. One of the barriers to the wide scale deployment of CBPs is the lack of operational experience with CBPs that could serve as a sound basis for justifying the use of CBPs for nuclear utilities. Utilities are hesitant to adopt CBPs because of concern over potential costs of implementation, and concern over regulatory approval. Regulators require a sound technical basis for the use of any procedure at the utilities; without operating experience to support the use CBPs, it is difficult to establish such a technical basis. In an effort to begin the process of developing a technical basis for CBPs, researchers at Idaho National Laboratory are partnering with industry to explore CBPs with the objective of defining requirements for CBPs and developing an industry-wide vision and path forward for the use of CBPs. This paper describes the results from a qualitative study aimed at defining requirements for CBPs to be used by field operators and maintenance technicians. (author)

  7. Reliability Of A Novel Intracardiac Electrogram Method For AV And VV Delay Optimization And Comparability To Echocardiography Procedure For Determining Optimal Conduction Delays In CRT Patients

    Directory of Open Access Journals (Sweden)

    N Reinsch

    2009-03-01

    Full Text Available Background: Echocardiography is widely used to optimize CRT programming. A novel intracardiac electrogram method (IEGM was recently developed as an automated programmer-based method, designed to calculate optimal atrioventricular (AV and interventricular (VV delays and provide optimized delay values as an alternative to standard echocardiographic assessment.Objective: This study was aimed at determining the reliability of this new method. Furthermore the comparability of IEGM to existing echocardiographic parameters for determining optimal conduction delays was verified.Methods: Eleven patients (age 62.9± 8.7; 81% male; 73% ischemic, previously implanted with a cardiac resynchronisation therapy defibrillator (CRT-D underwent both echocardiographic and IEGM-based delay optimization.Results: Applying the IEGM method, concordance of three consecutively performed measurements was found in 3 (27% patients for AV delay and in 5 (45% patients for VV delay. Intra-individual variation between three measurements as assessed by the IEGM technique was up to 20 ms (AV: n=6; VV: n=4. E-wave, diastolic filling time and septal-to-lateral wall motion delay emerged as significantly different between the echo and IEGM optimization techniques (p < 0.05. The final AV delay setting was significantly different between both methods (echo: 126.4 ± 29.4 ms, IEGM: 183.6 ± 16.3 ms; p < 0.001; correlation: R = 0.573, p = 0.066. VV delay showed significant differences for optimized delays (echo: 46.4 ± 23.8 ms, IEGM: 10.9 ± 7.0 ms; p <0.01; correlation: R = -0.278, p = 0.407.Conclusion: The automated programmer-based IEGM-based method provides a simple and safe method to perform CRT optimization. However, the reliability of this method appears to be limited. Thus, it remains difficult for the examiner to determine the optimal hemodynamic settings. Additionally, as there was no correlation between the optimal AV- and VV-delays calculated by the IEGM method and the echo

  8. Optimization of near and far patterns field in InxGa1-xN Lasers

    International Nuclear Information System (INIS)

    Martín, Juan A.; Mon, E.; Sánchez, M.

    2008-01-01

    The introduction on the market of lasers based on In x Ga 1-x N emitted at short wavelengths (λ = 430-450 nm), has enabled a considerable increase of the density of data storage on optical discs. However, despite the successes in the manufacture of these lasers are still far from being optimized. One of the difficulties present in these structures is the technological difficulty to grow In x Ga 1-x N cladding layers with high aluminum content (x>0.13) and wide enough to ensure the necessary optical confinement. This difficulty is due to the network constant difference between the Al x Ga 1-x N and the GaN and the presence of narrow cladding layers causes the undesirable high-order modes in [1] far field patterns. This paper analyzes the influence of the thickness of the layers that form the structure on the patterns of field near and far In x Ga 1-x N structures with multiple quantum wells in the active area. Structures are compared with staggered and parabolic variation of the refractive index. Found that with appropriate combinations of the thickness of this layer the detrimental effects that appear in from near and far field patterns can be eliminated without the need to grow very wide cladding layers, which represents an alternative solution to this technological problem [2]. [1] M. Onomura et al, IEEE J. Sel. Top. Quantum Electron. 5 (1999) 76. [2] J.A. Martín et al. Superlattices and Microstructures 43 (200 8) 575.

  9. Mobile Computerized Procedure System for the Improved Situation Awareness among Field Workers and Main Control Room Operators

    International Nuclear Information System (INIS)

    Lee, Sungjin; Seong, Nokyu; Jung, Yeonsub

    2013-01-01

    This paper explains the technical issues of the mobile CPS (m-CPS) in the conceptual development stage. The proposed m-CPS can be developed with many recent technologies in the various industry fields based on CRI CPS. Performance and stability of CRI CPS have been tested several times until now. It is expected that more human errors can be reduced by the m-CPS through improved situation awareness and human performance tools for local workers and MCR operators. Some considerations as well as mentioned ones will be reflected in the m-CPS development. Human errors can occur during the test and maintenance of the generator, safety injection system and reactor coolant inventory in nuclear power plants (NPPs). Most of human errors have been occurred by the omission of the prevention techniques such as the self-check, the peer-check, the concurrent verification and etc. Another important reason is the insufficient information sharing among main control room (MCR) operators and field workers. Various field service automation tools have been developed with recent information technology in many countries. APR1400 computerized procedure system (CPS) has been developed for the MCR operators of Shin-Kori 3 and 4 units. Especially, the concurrent verification support design is applied in the construction project of Shin-Hanul 1 and 2 CPS. KHNP central research institute (CRI) expects that the extended application of CPS including the field activity, that is a kind of mobile CPS, can enhance the reduction of human errors

  10. Optimization and application of an extraction procedure to determine drugs of abuse in solid environmental matrices of Turia River Basin

    Science.gov (United States)

    Andres, Maria Jesus; Alvarez, Rodrigo; Andreu, Vicente; Pico, Yolanda

    2015-04-01

    After their consumption, drug of abuse are excreted through urine or faeces, as parent compound or as secondary metabolites that arrive to wastewater treatment plants. Accordingly, the incomplete removal of these compounds in the treatment plants could release them into environmental compartments [1]. This scenario needs attention from an ecotoxicological perspective because their possible negative effects [2]. The aim of this study is to optimize and apply a solvent extraction and solid phase clean-up methodology to obtain a valid procedure for the extraction of these compounds in different solid matrices. Amphetamine, methamphetamine, ethylamphetamine, ecstasy, ethylone, bk-MMBDB and MBDB belong to phenylethylamine group; codeine and ketamine belong to opioid and phencyclidine group, respectively, and benzoylecgonine is the major excreted metabolite of the alkaloid cocaine. To optimize the method to determinate drugs of abuse in environmental solid matrices, two replicates and one blank were prepared for each sample of sediment. They were prepared by adding 1 g of sediment sample, 5 mL of buffer (methanol-Mc Ilvaine 50:50) and internal standard to obtain a final concentration in the extract of 25 ng/g. Also standards of drugs of abuse were added to the replicates to obtain a final concentration of 100 ng/g. Then all samples were shaken, sonicated and centrifuged and the supernatant was separated and placed in a 250 mL volumetric flask, which was filled the rest with distilled water. SPE was carried out with Strata-X cartridges and 250 mL of sample were passed through them. The extracts were eluted with 6 mL of methanol, evaporated to dryness and reconstituted in 1 mL of methanol-water 1:9. One of the replicates was filtrated through 0.22 μm pore size and the others were not. The samples were determined by liquid chromatography triple quadrupole mass spectrometry (LC-QqQ-MS/MS) using an electrospray ionization source (ESI) in positive ionization mode. The results

  11. Procedure to determine the optimal parameters of the main primary coolant pump after compacting the FRG-1 reactor. Pt. 2. Partial structures of the procedure

    International Nuclear Information System (INIS)

    Pihowicz, W.

    1999-01-01

    On the basis of an extensive physical and technical analysis the partial structures of the procedure had been developed. They represent a logical linkage of determination elements in the form of decision and result units. The developed partial structures enable to determine the physical parameters, which characterize the primary circuit together with the compact core as well as the main primary coolant pump coming into question after compacting the core. The report also contains a discussions and a comparison of the partial structures. (orig.) [de

  12. Optimized Spectrometers Characterization Procedure for Near Ground Support of ESA FLEX Observations: Part 1 Spectral Calibration and Characterisation

    Directory of Open Access Journals (Sweden)

    Laura Mihai

    2018-02-01

    Full Text Available The paper presents two procedures for the wavelength calibration, in the oxygen telluric absorption spectral bands (O2-A, λc = 687 nm and O2-B, λc = 760.6 nm, of field fixed-point spectrometers used for reflectance and Sun-induced fluorescence measurements. In the first case, Ne and Ar pen-type spectral lamps were employed, while the second approach is based on a double monochromator setup. The double monochromator system was characterized for the estimation of errors associated with different operating configurations. The proposed methods were applied to three Piccolo Doppio-type systems built around two QE Pros and one USB2 + H16355 Ocean Optics spectrometers. The wavelength calibration errors for all the calibrations performed on the three spectrometers are reported and potential methodological improvements discussed. The suggested calibration methods were validated, as the wavelength corrections obtained by both techniques for the QE Pro designed for fluorescence investigations were similar. However, it is recommended that a neon emission line source, as well as an argon or mercury-argon source be used to have a reference wavelength closer to the O2-B feature. The wavelength calibration can then be optimised as close to the O2-B and O2-A features as possible. The monochromator approach could also be used, but that instrument would need to be fully characterized prior to use, and although it may offer a more accurate calibration, as it could be tuned to emit light at the same wavelengths as the absorption features, it would be more time consuming as it is a scanning approach.

  13. Solve: a non linear least-squares code and its application to the optimal placement of torsatron vertical field coils

    International Nuclear Information System (INIS)

    Aspinall, J.

    1982-01-01

    A computational method was developed which alleviates the need for lengthy parametric scans as part of a design process. The method makes use of a least squares algorithm to find the optimal value of a parameter vector. Optimal is defined in terms of a utility function prescribed by the user. The placement of the vertical field coils of a torsatron is such a non linear problem

  14. Investigation on the optimal magnetic field of a cusp electron gun for a W-band gyro-TWA

    Science.gov (United States)

    Zhang, Liang; He, Wenlong; Donaldson, Craig R.; Cross, Adrian W.

    2018-05-01

    High efficiency and broadband operation of a gyrotron traveling wave amplifier (gyro-TWA) require a high-quality electron beam with low-velocity spreads. The beam velocity spreads are mainly due to the differences of the electric and magnetic fields that the electrons withstand the electron gun. This paper investigates the possibility to decouple the design of electron gun geometry and the magnet system while still achieving optimal results, through a case study of designing a cusp electron gun for a W-band gyro-TWA. A global multiple-objective optimization routing was used to optimize the electron gun geometry for different predefined magnetic field profiles individually. Their results were compared and the properties of the required magnetic field profile are summarized.

  15. Multiobjective optimization model of intersection signal timing considering emissions based on field data: A case study of Beijing.

    Science.gov (United States)

    Kou, Weibin; Chen, Xumei; Yu, Lei; Gong, Huibo

    2018-04-18

    Most existing signal timing models are aimed to minimize the total delay and stops at intersections, without considering environmental factors. This paper analyzes the trade-off between vehicle emissions and traffic efficiencies on the basis of field data. First, considering the different operating modes of cruising, acceleration, deceleration, and idling, field data of emissions and Global Positioning System (GPS) are collected to estimate emission rates for heavy-duty and light-duty vehicles. Second, multiobjective signal timing optimization model is established based on a genetic algorithm to minimize delay, stops, and emissions. Finally, a case study is conducted in Beijing. Nine scenarios are designed considering different weights of emission and traffic efficiency. The results compared with those using Highway Capacity Manual (HCM) 2010 show that signal timing optimized by the model proposed in this paper can decrease vehicles delay and emissions more significantly. The optimization model can be applied in different cities, which provides supports for eco-signal design and development. Vehicle emissions are heavily at signal intersections in urban area. The multiobjective signal timing optimization model is proposed considering the trade-off between vehicle emissions and traffic efficiencies on the basis of field data. The results indicate that signal timing optimized by the model proposed in this paper can decrease vehicle emissions and delays more significantly. The optimization model can be applied in different cities, which provides supports for eco-signal design and development.

  16. Optimization and evaluation of asymmetric flow field-flow fractionation of silver nanoparticles.

    Science.gov (United States)

    Loeschner, Katrin; Navratilova, Jana; Legros, Samuel; Wagner, Stephan; Grombe, Ringo; Snell, James; von der Kammer, Frank; Larsen, Erik H

    2013-01-11

    Asymmetric flow field-flow fractionation (AF(4)) in combination with on-line optical detection and mass spectrometry is one of the most promising methods for separation and quantification of nanoparticles (NPs) in complex matrices including food. However, to obtain meaningful results regarding especially the NP size distribution a number of parameters influencing the separation need to be optimized. This paper describes the development of a separation method for polyvinylpyrrolidone-stabilized silver nanoparticles (AgNPs) in aqueous suspension. Carrier liquid composition, membrane material, cross flow rate and spacer height were shown to have a significant influence on the recoveries and retention times of the nanoparticles. Focus time and focus flow rate were optimized with regard to minimum elution of AgNPs in the void volume. The developed method was successfully tested for injected masses of AgNPs from 0.2 to 5.0 μg. The on-line combination of AF(4) with detection methods including ICP-MS, light absorbance and light scattering was helpful because each detector provided different types of information about the eluting NP fraction. Differences in the time-resolved appearance of the signals obtained by the three detection methods were explained based on the physical origin of the signal. Two different approaches for conversion of retention times of AgNPs to their corresponding sizes and size distributions were tested and compared, namely size calibration with polystyrene nanoparticles (PSNPs) and calculations of size based on AF(4) theory. Fraction collection followed by transmission electron microscopy was performed to confirm the obtained size distributions and to obtain further information regarding the AgNP shape. Characteristics of the absorbance spectra were used to confirm the presence of non-spherical AgNP. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Survival comparison of the Ross procedure and mechanical valve replacement with optimal self-management anticoagulation therapy: propensity-matched cohort study.

    Science.gov (United States)

    Mokhles, M Mostafa; Körtke, Heinrich; Stierle, Ulrich; Wagner, Otto; Charitos, Efstratios I; Bogers, Ad J J C; Gummert, Jan; Sievers, Hans-Hinrich; Takkenberg, Johanna J M

    2011-01-04

    It is suggested that in young adults the Ross procedure results in better late patient survival compared with mechanical prosthesis implantation. We performed a propensity score-matched study that assessed late survival in young adult patients after a Ross procedure versus that after mechanical aortic valve replacement with optimal self-management anticoagulation therapy. We selected 918 Ross patients and 406 mechanical valve patients 18 to 60 years of age without dissection, aneurysm, or mitral valve replacement who survived an elective procedure (1994 to 2008). With the use of propensity score matching, late survival was compared between the 2 groups. Two hundred fifty-three patients with a mechanical valve (mean follow-up, 6.3 years) could be propensity matched to a Ross patient (mean follow-up, 5.1 years). Mean age of the matched cohort was 47.3 years in the Ross procedure group and 48.0 years in the mechanical valve group (P=0.17); the ratio of male to female patients was 3.2 in the Ross procedure group and 2.7 in the mechanical valve group (P=0.46). Linearized all-cause mortality rate was 0.53% per patient-year in the Ross procedure group compared with 0.30% per patient-year in the mechanical valve group (matched hazard ratio, 1.86; 95% confidence interval, 0.58 to 5.91; P=0.32). Late survival was comparable to that of the general German population. In comparable patients, there is no late survival difference in the first postoperative decade between the Ross procedure and mechanical aortic valve implantation with optimal anticoagulation self-management. Survival in these selected young adult patients closely resembles that of the general population, possibly as a result of highly specialized anticoagulation self-management, better timing of surgery, and improved patient selection in recent years.

  18. Alternatives for optimization of the heavy oil production in onshore marginal fields in Brazil; Alternativas para otimizacao de producao de oleos pesados em campos marginais terrestres no Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Arlindo Antonio de [PETROBRAS, Rio de Janeiro, RJ (Brazil); Santos, Edmilson Moutinho dos [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Eletrotecnica e Energia. Programa Interunidades de Pos-graduacao em Energia

    2004-07-01

    The intention of this article is to present possible alternatives for optimization of the production of heavy oils in marginal onshore fields in Brazil. The use of gas micro-turbines, the application of SAGD (Steam Assisted Gravity Drainage), the use of the drilling technique for river crossing and to a proposal for a new system of the rig less workovers are approached. The focus is the search of the increment of the production, the increase of the factor of final recovery, the global reduction of the costs and the minimization of the environmental impacts. The volumes of heavy oils in Campos Basin and in national onshore areas they are significant and, therefore, techniques and procedures that optimize its production are strategic. In the Brazilian Northeast there are a series of small fields of low productivity, in general of heavy oils, some in production there are more than twenty years that need of a reduction of the cost for barrel to continue producing. A realistic and responsible posture with the use of probabilistics concepts, techniques of engineering of the reliability, adoption of 'tolerable' levels of risk (associate to the return), attendance on line of the sceneries, premises and criteria, (proposal of the methodology GERISK), are relevant factors that can propitiate not only the reduction of the cost for produced barrel as well as to take the an increase of the factor of final recovery of the field. (author)

  19. Alternatives for optimization of the heavy oil production in onshore marginal fields in Brazil; Alternativas para otimizacao de producao de oleos pesados em campos marginais terrestres no Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Arlindo Antonio de [PETROBRAS, Rio de Janeiro, RJ (Brazil); Santos, Edmilson Moutinho dos [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Eletrotecnica e Energia. Programa Interunidades de Pos-graduacao em Energia

    2004-07-01

    The intention of this article is to present possible alternatives for optimization of the production of heavy oils in marginal onshore fields in Brazil. The use of gas micro-turbines, the application of SAGD (Steam Assisted Gravity Drainage), the use of the drilling technique for river crossing and to a proposal for a new system of the rig less workovers are approached. The focus is the search of the increment of the production, the increase of the factor of final recovery, the global reduction of the costs and the minimization of the environmental impacts. The volumes of heavy oils in Campos Basin and in national onshore areas they are significant and, therefore, techniques and procedures that optimize its production are strategic. In the Brazilian Northeast there are a series of small fields of low productivity, in general of heavy oils, some in production there are more than twenty years that need of a reduction of the cost for barrel to continue producing. A realistic and responsible posture with the use of probabilistics concepts, techniques of engineering of the reliability, adoption of 'tolerable' levels of risk (associate to the return), attendance on line of the sceneries, premises and criteria, (proposal of the methodology GERISK), are relevant factors that can propitiate not only the reduction of the cost for produced barrel as well as to take the an increase of the factor of final recovery of the field. (author)

  20. Optimization of a novel large field of view distortion phantom for MR-only treatment planning.

    Science.gov (United States)

    Price, Ryan G; Knight, Robert A; Hwang, Ken-Pin; Bayram, Ersin; Nejad-Davarani, Siamak P; Glide-Hurst, Carri K

    2017-07-01

    MR-only treatment planning requires images of high geometric fidelity, particularly for large fields of view (FOV). However, the availability of large FOV distortion phantoms with analysis software is currently limited. This work sought to optimize a modular distortion phantom to accommodate multiple bore configurations and implement distortion characterization in a widely implementable solution. To determine candidate materials, 1.0 T MR and CT images were acquired of twelve urethane foam samples of various densities and strengths. Samples were precision-machined to accommodate 6 mm diameter paintballs used as landmarks. Final material candidates were selected by balancing strength, machinability, weight, and cost. Bore sizes and minimum aperture width resulting from couch position were tabulated from the literature (14 systems, 5 vendors). Bore geometry and couch position were simulated using MATLAB to generate machine-specific models to optimize the phantom build. Previously developed software for distortion characterization was modified for several magnet geometries (1.0 T, 1.5 T, 3.0 T), compared against previously published 1.0 T results, and integrated into the 3D Slicer application platform. All foam samples provided sufficient MR image contrast with paintball landmarks. Urethane foam (compressive strength ∼1000 psi, density ~20 lb/ft 3 ) was selected for its accurate machinability and weight characteristics. For smaller bores, a phantom version with the following parameters was used: 15 foam plates, 55 × 55 × 37.5 cm 3 (L×W×H), 5,082 landmarks, and weight ~30 kg. To accommodate > 70 cm wide bores, an extended build used 20 plates spanning 55 × 55 × 50 cm 3 with 7,497 landmarks and weight ~44 kg. Distortion characterization software was implemented as an external module into 3D Slicer's plugin framework and results agreed with the literature. The design and implementation of a modular, extendable distortion phantom was optimized for several bore

  1. Optimal estimation of spatially variable recharge and transmissivity fields under steady-state groundwater flow. Part 2. Case study

    Science.gov (United States)

    Graham, Wendy D.; Neff, Christina R.

    1994-05-01

    The first-order analytical solution of the inverse problem for estimating spatially variable recharge and transmissivity under steady-state groundwater flow, developed in Part 1 is applied to the Upper Floridan Aquifer in NE Florida. Parameters characterizing the statistical structure of the log-transmissivity and head fields are estimated from 152 measurements of transmissivity and 146 measurements of hydraulic head available in the study region. Optimal estimates of the recharge, transmissivity and head fields are produced throughout the study region by conditioning on the nearest 10 available transmissivity measurements and the nearest 10 available head measurements. Head observations are shown to provide valuable information for estimating both the transmissivity and the recharge fields. Accurate numerical groundwater model predictions of the aquifer flow system are obtained using the optimal transmissivity and recharge fields as input parameters, and the optimal head field to define boundary conditions. For this case study, both the transmissivity field and the uncertainty of the transmissivity field prediction are poorly estimated, when the effects of random recharge are neglected.

  2. Discrimination of Arabic-named applicants in the Netherlands: An internet-based field experiment examining different phases in online recruitment procedures

    NARCIS (Netherlands)

    Blommaert, E.C.C.A.; Coenders, M.T.A.; Tubergen, F.A. van

    2014-01-01

    This study examines discrimination of Arabic-named applicants in online recruitment procedures in the Netherlands. We develop and implement a new field experiment approach, posting fictitious resumes (n = 636) on two online resume databases. Two phases of recruitment procedures are examined:

  3. Multiple fields may offer better esophagus sparing without increased probability of lung toxicity in optimized IMRT of lung tumors

    International Nuclear Information System (INIS)

    Chapet, Olivier; Fraass, Benedick A.; Haken, Randall K. ten

    2006-01-01

    Purpose: To evaluate whether increasing numbers of intensity-modulated radiation therapy (IMRT) fields enhance lung-tumor dose without additional predicted toxicity for difficult planning geometries. Methods and Materials: Data from 8 previous three dimensional conformal radiation therapy (3D-CRT) patients with tumors located in various regions of each lung, but with planning target volumes (PTVs) overlapping part of the esophagus, were used as input. Four optimized-beamlet IMRT plans (1 plan that used the 3D-CRT beam arrangement and 3 plans with 3, 5, or 7 axial, but predominantly one-sided, fields) were compared. For IMRT, the equivalent uniform dose (EUD) in the whole PTV was optimized simultaneously with that in a reduced PTV exclusive of the esophagus. Normal-tissue complication probability-based costlets were used for the esophagus, heart, and lung. Results: Overall, IMRT plans (optimized by use of EUD to judiciously allow relaxed PTV dose homogeneity) result in better minimum PTV isodose surface coverage and better average EUD values than does conformal planning; dose generally increases with the number of fields. Even 7-field plans do not significantly alter normal-lung mean-dose values or lung volumes that receive more than 13, 20, or 30 Gy. Conclusion: Optimized many-field IMRT plans can lead to escalated lung-tumor dose in the special case of esophagus overlapping PTV, without unacceptable alteration in the dose distribution to normal lung

  4. General optimization procedure towards the design of a new family of minimal parameter spin-component-scaled double-hybrid density functional theory.

    Science.gov (United States)

    Roch, Loïc M; Baldridge, Kim K

    2017-10-04

    A general optimization procedure towards the development and implementation of a new family of minimal parameter spin-component-scaled double-hybrid (mSD) density functional theory (DFT) is presented. The nature of the proposed exchange-correlation functional establishes a methodology with minimal empiricism. This new family of double-hybrid (DH) density functionals is demonstrated using the PBEPBE functional, illustrating the optimization procedure to the mSD-PBEPBE method, and the performance characteristics shown for a set of non-covalent complexes covering a broad regime of weak interactions. With only two parameters, mSD-PBEPBE and its cost-effective counterpart, RI-mSD-PBEPBE, show a mean absolute error of ca. 0.4 kcal mol -1 averaged over 66 weak interacting systems. Following a successive 2D-grid refinement for a CBS extrapolation of the coefficients, the optimization procedure can be recommended for the design and implementation of a variety of additional DH methods using any of the plethora of currently available functionals.

  5. Self-organization, free energy minimization, and optimal grip on a field of affordances

    Directory of Open Access Journals (Sweden)

    Jelle eBruineberg

    2014-08-01

    Full Text Available In this paper, we set out to develop a theoretical and conceptual framework for the new field of Radical Embodied Cognitive Neuroscience. This framework should be able to integrate insights from several relevant disciplines: theory on embodied cognition, ecological psychology, phenomenology, dynamical systems theory, and neurodynamics. We suggest that the main task of Radical Embodied Cognitive Neuroscience is to investigate the phenomenon of skilled intentionality from the perspective of the self-organization of the brain-body-environment system, while doing justice to the phenomenology of skilled action. In previous work, we have characterized skilled intentionality as the organism’s tendency towards an optimal grip on multiple relevant affordances simultaneously. Affordances are possibilities for action provided by the environment. In the first part of this paper, we introduce the notion of skilled intentionality and the phenomenon of responsiveness to a field of relevant affordances. Second, we use Friston’s work on neurodynamics, but embed a very minimal version of his Free Energy Principle in the ecological niche of the animal. Thus amended, this principle is helpful for understanding the embeddedness of neurodynamics within the dynamics of the brain-body-environment system. Next, we show how we can use this adjusted principle to understand the neurodynamics of selective openness to the environment: interacting action-readiness patterns at multiple timescales contribute to the organism’s selective openness to relevant affordances. In the final part of the paper, we emphasize the important role of metastable dynamics in both the brain and the brain-body-environment system for adequate affordance-responsiveness. We exemplify our integrative approach by presenting research on the impact of Deep Brain Stimulation on affordance responsiveness of OCD patients.

  6. Self-organization, free energy minimization, and optimal grip on a field of affordances.

    Science.gov (United States)

    Bruineberg, Jelle; Rietveld, Erik

    2014-01-01

    In this paper, we set out to develop a theoretical and conceptual framework for the new field of Radical Embodied Cognitive Neuroscience. This framework should be able to integrate insights from several relevant disciplines: theory on embodied cognition, ecological psychology, phenomenology, dynamical systems theory, and neurodynamics. We suggest that the main task of Radical Embodied Cognitive Neuroscience is to investigate the phenomenon of skilled intentionality from the perspective of the self-organization of the brain-body-environment system, while doing justice to the phenomenology of skilled action. In previous work, we have characterized skilled intentionality as the organism's tendency toward an optimal grip on multiple relevant affordances simultaneously. Affordances are possibilities for action provided by the environment. In the first part of this paper, we introduce the notion of skilled intentionality and the phenomenon of responsiveness to a field of relevant affordances. Second, we use Friston's work on neurodynamics, but embed a very minimal version of his Free Energy Principle in the ecological niche of the animal. Thus amended, this principle is helpful for understanding the embeddedness of neurodynamics within the dynamics of the system "brain-body-landscape of affordances." Next, we show how we can use this adjusted principle to understand the neurodynamics of selective openness to the environment: interacting action-readiness patterns at multiple timescales contribute to the organism's selective openness to relevant affordances. In the final part of the paper, we emphasize the important role of metastable dynamics in both the brain and the brain-body-environment system for adequate affordance-responsiveness. We exemplify our integrative approach by presenting research on the impact of Deep Brain Stimulation on affordance responsiveness of OCD patients.

  7. Optimization of measurement methods for a multi-frequency electromagnetic field from mobile phone base station using broadband EMF meter

    Directory of Open Access Journals (Sweden)

    Paweł Bieńkowski

    2015-10-01

    Full Text Available Background: This paper presents the characteristics of the mobile phone base station (BS as an electromagnetic field (EMF source. The most common system configurations with their construction are described. The parameters of radiated EMF in the context of the access to methods and other parameters of the radio transmission are discussed. Attention was also paid to antennas that are used in this technology. Material and Methods: The influence of individual components of a multi-frequency EMF, most commonly found in the BS surroundings, on the resultant EMF strength value indicated by popular broadband EMF meters was analyzed. The examples of metrological characteristics of the most common EMF probes and 2 measurement scenarios of the multisystem base station, with and without microwave relays, are shown. Results: The presented method for measuring the multi-frequency EMF using 2 broadband probes allows for the significant minimization of measurement uncertainty. Equations and formulas that can be used to calculate the actual EMF intensity from multi-frequency sources are shown. They have been verified in the laboratory conditions on a specific standard setup as well as in real conditions in a survey of the existing base station with microwave relays. Conclusions: Presented measurement methodology of multi-frequency EMF from BS with microwave relays, validated both in laboratory and real conditions. It has been proven that the described measurement methodology is the optimal approach to the evaluation of EMF exposure in BS surrounding. Alternative approaches with much greater uncertainty (precaution method or more complex measuring procedure (sources exclusion method are also presented. Med Pr 2015;66(5:701–712

  8. [Optimization of measurement methods for a multi-frequency electromagnetic field from mobile phone base station using broadband EMF meter].

    Science.gov (United States)

    Bieńkowski, Paweł; Cała, Paweł; Zubrzak, Bartłomiej

    2015-01-01

    This paper presents the characteristics of the mobile phone base station (BS) as an electromagnetic field (EMF) source. The most common system configurations with their construction are described. The parameters of radiated EMF in the context of the access to methods and other parameters of the radio transmission are discussed. Attention was also paid to antennas that are used in this technology. The influence of individual components of a multi-frequency EMF, most commonly found in the BS surroundings, on the resultant EMF strength value indicated by popular broadband EMF meters was analyzed. The examples of metrological characteristics of the most common EMF probes and 2 measurement scenarios of the multisystem base station, with and without microwave relays, are shown. The presented method for measuring the multi-frequency EMF using 2 broadband probes allows for the significant minimization of measurement uncertainty. Equations and formulas that can be used to calculate the actual EMF intensity from multi-frequency sources are shown. They have been verified in the laboratory conditions on a specific standard setup as well as in real conditions in a survey of the existing base station with microwave relays. Presented measurement methodology of multi-frequency EMF from BS with microwave relays, validated both in laboratory and real conditions. It has been proven that the described measurement methodology is the optimal approach to the evaluation of EMF exposure in BS surrounding. Alternative approaches with much greater uncertainty (precaution method) or more complex measuring procedure (sources exclusion method) are also presented). This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  9. Existence of optimal controls for systems governed by mean-field ...

    African Journals Online (AJOL)

    In this paper, we study the existence of an optimal control for systems, governed by stochastic dierential equations of mean-eld type. For non linear systems, we prove the existence of an optimal relaxed control, by using tightness techniques and Skorokhod selection theorem. The optimal control is a measure valued process ...

  10. Optimal and fast E/B separation with a dual messenger field

    Science.gov (United States)

    Kodi Ramanah, Doogesh; Lavaux, Guilhem; Wandelt, Benjamin D.

    2018-05-01

    We adapt our recently proposed dual messenger algorithm for spin field reconstruction and showcase its efficiency and effectiveness in Wiener filtering polarized cosmic microwave background (CMB) maps. Unlike conventional preconditioned conjugate gradient (PCG) solvers, our preconditioner-free technique can deal with high-resolution joint temperature and polarization maps with inhomogeneous noise distributions and arbitrary mask geometries with relative ease. Various convergence diagnostics illustrate the high quality of the dual messenger reconstruction. In contrast, the PCG implementation fails to converge to a reasonable solution for the specific problem considered. The implementation of the dual messenger method is straightforward and guarantees numerical stability and convergence. We show how the algorithm can be modified to generate fluctuation maps, which, combined with the Wiener filter solution, yield unbiased constrained signal realizations, consistent with observed data. This algorithm presents a pathway to exact global analyses of high-resolution and high-sensitivity CMB data for a statistically optimal separation of E and B modes. It is therefore relevant for current and next-generation CMB experiments, in the quest for the elusive primordial B-mode signal.

  11. Development of Optimal Viscous Dampers for RC Structures in Near Field Ground Motions

    International Nuclear Information System (INIS)

    Puthanpurayil, Arun M.; Reynolds, Paul

    2008-01-01

    Recent researches show that more than 50% of the economic loss in earthquakes is due to damage of non-structural elements: $8 billion loss in the 1989 Loma Prieta earthquake and $18.5 billion in the 1994 Northridge earthquake. An approach to reduce the economic loss during a seismic event without compromising the structural safety aspect is to incorporate special mechanical devices like fluid viscous dampers in the parent structural system. A recent study carried out to assess the efficacy of viscous dampers in reducing nonstructural damage of low, medium and high rise structures shows that; linear dampers are well suited for low rise category whereas the medium and high rise category requires nonlinear dampers. In this paper an analytical approach is adopted to derive the optimal combination of damper design parameters for all the three categories of structure subjected to near field ground motion. Linear time history analysis by direct time integration was carried out for the linear viscous dampers, while the parameters of the nonlinear viscous dampers were obtained using nonlinear modal time history analysis (Fast Nonlinear analysis). The results of the study are presented in the form of a set of design curves which can be used for the initial selection of parameters for Damper design

  12. Instrument response measurements of ion mobility spectrometers in situ: maintaining optimal system performance of fielded systems

    Science.gov (United States)

    Wallis, Eric; Griffin, Todd M.; Popkie, Norm, Jr.; Eagan, Michael A.; McAtee, Robert F.; Vrazel, Danet; McKinly, Jim

    2005-05-01

    Ion Mobility Spectroscopy (IMS) is the most widespread detection technique in use by the military for the detection of chemical warfare agents, explosives, and other threat agents. Moreover, its role in homeland security and force protection has expanded due, in part, to its good sensitivity, low power, lightweight, and reasonable cost. With the increased use of IMS systems as continuous monitors, it becomes necessary to develop tools and methodologies to ensure optimal performance over a wide range of conditions and extended periods of time. Namely, instrument calibration is needed to ensure proper sensitivity and to correct for matrix or environmental effects. We have developed methodologies to deal with the semi-quantitative nature of IMS and allow us to generate response curves that allow a gauge of instrument performance and maintenance requirements. This instrumentation communicates to the IMS systems via a software interface that was developed in-house. The software measures system response, logs information to a database, and generates the response curves. This paper will discuss the instrumentation, software, data collected, and initial results from fielded systems.

  13. Optimization of cement composites with the use of fillers from the Chechen Republic fields

    Directory of Open Access Journals (Sweden)

    Balatkhanova Elita Mahmudovna

    Full Text Available The fillers together with binders take part in microstructure formation of matrix basis and contact zones of a composite. The advantage of cement matrix structure with a filler is that inner defects are localized in it - microcracks, macropores and capillary pores, as well as that their quantity, their sizes and stress concentration decrease. Structure formation of filled cement composites is based on the processes taking place in the contact of liquid and stiff phases, which means, it depends on the quantitative relation of the cement, fillers and water, and also dispersivity and physical and chemical activity of the fillers. In the article the authors offer research results of the processes of hydration and physical-mechanical properties of cement composites with fillers from the fields of the Chechen Republic. Research results of heat cement systems are presented, modified by fine fillers. Optimal composition of cement composites filled with powders of quartz, sandstone, river and a mountain limestone of different particle size composition, characterized by a high strength, are obtained.

  14. Transducer project and optimization of the ultra low magnetic field NMR tomograph reception system system

    International Nuclear Information System (INIS)

    Vidoto, Edson Luiz Gea

    1995-01-01

    The aim of the present work was to optimize the signal to noise ratio in our NMR imaging system (TORM 005) by improving transducer's reception quality through better designed coils, balanced tuning circuit for this coils and power decoupling circuits and by reducing interference from the electromagnetic environment. For this purpose, we had to modify the internal electromagnetic shielding and incorporate line filters in the more critical signals paths. Also, new types of coils were developed, improving the signal to noise ratio, and allowing us to make clinical exams with superior quality for several anatomies. Balanced circuits for tuning and matching of the coil were studied and built, allowing a reduction of the coil losses because patient's load. This produced a more reliable coil tuning after positioning each new patient. Circuits to avoid the receiver input overload and decoupling circuits for the isolation of receiver coils from excitation coil were designed and incorporated to the TORM 005. All these alterations of our imaging system (TORM 005) contributed to a significant improvement in the signal to noise ratio, reliability and reproducibility of the system. This permitted to operate the system routinely for clinical applications, research and development in the area of ultra low magnetic field tomography. (author)

  15. The Adjoint Method for The Optimization of Brachytherapy and Radiotherapy Patient Treatment Planning Procedures Using Monte Carlo Calculations

    International Nuclear Information System (INIS)

    Henderson, D.L.; Yoo, S.; Kowalok, M.; Mackie, T.R.; Thomadsen, B.R.

    2001-01-01

    The goal of this project is to investigate the use of the adjoint method, commonly used in the reactor physics community, for the optimization of radiation therapy patient treatment plans. Two different types of radiation therapy are being examined, interstitial brachytherapy and radiotherapy. In brachytherapy radioactive sources are surgically implanted within the diseased organ such as the prostate to treat the cancerous tissue. With radiotherapy, the x-ray source is usually located at a distance of about 1-meter from the patient and focused on the treatment area. For brachytherapy the optimization phase of the treatment plan consists of determining the optimal placement of the radioactive sources, which delivers the prescribed dose to the disease tissue while simultaneously sparing (reducing) the dose to sensitive tissue and organs. For external beam radiation therapy the optimization phase of the treatment plan consists of determining the optimal direction and intensity of beam, which provides complete coverage of the tumor region with the prescribed dose while simultaneously avoiding sensitive tissue areas. For both therapy methods, the optimal treatment plan is one in which the diseased tissue has been treated with the prescribed dose and dose to the sensitive tissue and organs has been kept to a minimum

  16. ROXIE the Routine for the Optimization of Magnet X-sections, Inverse Field Computation and Coil End Design

    CERN Document Server

    Russenschuck, Stephan

    1999-01-01

    The ROXIE software program package has been developed for the design of the superconducting magnets for the LHC at CERN. The software is used as an approach towards the integrated design of superconducting magnets including feature-based coil geometry creation, conceptual design using genetic algorithms, optimization of the coil and iron cross-sections using a reduced vector-potential formulation, 3-D coil end geometry and field optimization using deterministic vector- optimization techniques, tolerance analysis, production of drawings by means of a DXF interface, end-spacer design with interfaces to CAD-CAM for the CNC machining of these pieces, and the tracing of manufacturing errors using field quality measurements. This paper gives an overview of the methods applied in the ROXIE program. (9 refs).

  17. Optimalization of selected RFID systems Parameters

    Directory of Open Access Journals (Sweden)

    Peter Vestenicky

    2004-01-01

    Full Text Available This paper describes procedure for maximization of RFID transponder read range. This is done by optimalization of magnetics field intensity at transponder place and by optimalization of antenna and transponder coils coupling factor. Results of this paper can be used for RFID with inductive loop, i.e. system working in near electromagnetic field.

  18. Seasonal variation of the impact of a stressful procedure on open field behaviour and blood corticosterone in laboratory mice.

    Science.gov (United States)

    Meyer, L; Caston, J; Mensah-Nyagan, A G

    2006-02-28

    Behavioural and hormonal seasonal changes are well documented in various vertebrate species living in their natural environment but circannual variations that may occur in laboratory animals reared in standard conditions are poorly investigated. This study shows that, in laboratory mice, the effects of stress on behavioural inhibition, investigatory behaviour and blood concentration of corticosterone are seasonally dependent. No consistency was observed between the reactivity of biological structures controlling the hormonal response to stress and the behavioural activities investigated at every period of the year. During the spring time, stress, which elicited a decrease of investigatory behaviour (estimated by the walking time in an open field), increased behavioural inhibition (estimated by the percentage of walking in the central area of the open field) as well as the blood corticosterone concentration in laboratory mice. In autumn, stress had no significant effect on behaviour despite the great hormonal concentration increase. The results reveal that, at certain period of the year, a stressful procedure is unable to affect behavioural parameters in laboratory mice which were maintained in constant 12-h dark/12-h light cycle. The report constitutes a novel piece of information suggesting a potential role of the endogenous biological clock in the modulation of stress response in mammals.

  19. Optimization of Wellhead Piping Design for Production Wells at Development of Steam-Water Geothermal Fields

    Directory of Open Access Journals (Sweden)

    A.N. Shulyupin

    2017-03-01

    Full Text Available At present, the exploitation of geothermal resources develops in a fair competition with other types of energy resources. This leads to actuality of questions which associated with the more efficient use of existing wells, because cost of their drilling is a significant share of geothermal projects. In domestic practice of development of geothermal resources the steam-water wells have greatest energy potential. One way to improve the performance of these wells is a providing of smooth change of direction of motion of steam-water mixture from the vertical, in the well, to the horizontal, in steam gathering system. Typical wellhead piping of domestic steam-water wells involves the removal of the mixture through a cross bar at a right angle. Cross bar can generate considerable pressure loss that increases the operating pressure at the mouth of the well and reduces flow rate. It seems reasonable to substitute the typical cross bar by smooth pipe bend. This reduces wellhead resistance coefficient by more than on 2. Increase of curvature radius of pipe bend reduces the pressure loss to a local resistance but increases the friction pressure loss. There is an optimal curvature radius of pipe bend for minimum pressure loss in view of a local resistance and friction in the pipe bend. Calculations have shown that the optimum value for the radius of curvature is found in the range from 1.4 to 4.5 tube internal diameters. However, for technological reasons it is recommended to choose the radius of curvature from 1.4 to 2.4 diameters. Mounting of smooth pipe bend on the wellhead can provide significant economic benefits. For Mutnovka field (Kamchatka, this effect is estimated at 17.5 million rubles in year.

  20. SU-E-T-262: Planning for Proton Pencil Beam Scanning (PBS): Applications of Gradient Optimization for Field Matching

    Energy Technology Data Exchange (ETDEWEB)

    Lin, H; Kirk, M; Zhai, H; Ding, X; Liu, H; Hill-Kayser, C; Lustig, R; Tochner, Z; Deville, C; Vapiwala, N; McDonough, J; Both, S [University Pennsylvania, Philadelphia, PA (United States)

    2014-06-01

    Purpose: To propose the gradient optimization(GO) approach in planning for matching proton PBS fields and present two commonly used applications in our institution. Methods: GO is employed for PBS field matching in the scenarios that when the size of the target is beyond the field size limit of the beam delivery system or matching is required for beams from different angles to either improve the sparing of important organs or to pass through a short and simple beam path. Overlap is designed between adjacent fields and in the overlapped junction, the dose was optimized such that it gradually decreases in one field and the decrease is compensated by increase from another field. Clinical applications of this approach on craniospinal irradiation(CSI) and whole pelvis treatment were presented. Mathematical model was developed to study the relationships between dose errors, setup errors and junction lengths. Results: Uniform and conformal dose coverage to the entire target volumes was achieved for both applications using GO approach. For CSI, the gradient matching (6.7cm junction) between fields overcame the complexity of planning associated with feathering match lines. A slow dose gradient in the junction area significantly reduced the sensitivity of the treatment to setup errors. For whole pelvis, gradient matching (4cm junction) between posterior fields for superior target and bilateral fields for inferior target provided dose sparing to organs such as bowel, bladder and rectum. For a setup error of 3 mm in longitudinal direction from one field, mathematical model predicted dose errors of 10%, 6% and 4.3% for junction length of 3, 5 and 7cm. Conclusion: This GO approach improves the quality of the PBS treatment plan with matching fields while maintaining the safety of treatment delivery relative to potential misalignments.

  1. SU-E-T-262: Planning for Proton Pencil Beam Scanning (PBS): Applications of Gradient Optimization for Field Matching

    International Nuclear Information System (INIS)

    Lin, H; Kirk, M; Zhai, H; Ding, X; Liu, H; Hill-Kayser, C; Lustig, R; Tochner, Z; Deville, C; Vapiwala, N; McDonough, J; Both, S

    2014-01-01

    Purpose: To propose the gradient optimization(GO) approach in planning for matching proton PBS fields and present two commonly used applications in our institution. Methods: GO is employed for PBS field matching in the scenarios that when the size of the target is beyond the field size limit of the beam delivery system or matching is required for beams from different angles to either improve the sparing of important organs or to pass through a short and simple beam path. Overlap is designed between adjacent fields and in the overlapped junction, the dose was optimized such that it gradually decreases in one field and the decrease is compensated by increase from another field. Clinical applications of this approach on craniospinal irradiation(CSI) and whole pelvis treatment were presented. Mathematical model was developed to study the relationships between dose errors, setup errors and junction lengths. Results: Uniform and conformal dose coverage to the entire target volumes was achieved for both applications using GO approach. For CSI, the gradient matching (6.7cm junction) between fields overcame the complexity of planning associated with feathering match lines. A slow dose gradient in the junction area significantly reduced the sensitivity of the treatment to setup errors. For whole pelvis, gradient matching (4cm junction) between posterior fields for superior target and bilateral fields for inferior target provided dose sparing to organs such as bowel, bladder and rectum. For a setup error of 3 mm in longitudinal direction from one field, mathematical model predicted dose errors of 10%, 6% and 4.3% for junction length of 3, 5 and 7cm. Conclusion: This GO approach improves the quality of the PBS treatment plan with matching fields while maintaining the safety of treatment delivery relative to potential misalignments

  2. ROXIE: Routine for the optimization of magnet X-sections, inverse field calculation and coil end design. Proceedings

    International Nuclear Information System (INIS)

    Russenschuck, S.

    1999-01-01

    The Large Hadron Collider (LHC) will provide proton-proton collisions with a center-of-mass energy of 14 TeV which requires high field superconducting magnets to guide the counter-rotating beams in the existing LEP tunnel with a circumference of about 27 km. The LHC magnet system consists of 1232 superconducting dipoles and 386 main quadrupoles together with about 20 different types of magnets for insertions and correction. The design and optimization of these magnets is dominated by the requirement of a extremely uniform field which is mainly defined by the layout of the superconducting coils. The program package ROXIE (Routine for the Optimization of magnet X-sections, Inverse field calculation and coil End design) has been developed for the design and optimization of the coil geometries in two and three dimensions. Recently it has been extended in a collaboration with the University of Graz, Austria, to the calculation of saturation induced effects using a reduced vector-potential FEM formulation. With the University of Stuttgart, Germany, a collaboration exists fro the application of the BEM-FEM coupling method for the 2D and 3D field calculation. ROXIE now also features a TCL-TK user interface. The growing number of ROXIE users inside and outside CERN gave rise to the idea of organizing the 'First International ROXIE Users Meeting and Workshop' at CERN, March 16-18, 1998 which brought together about 50 researchers in the field. This report contains the contributions to the workshop and describes the features of the program, the mathematical optimization techniques applied and gives examples of the recent design work carried out. It also gives the theoretical background for the field computation methods and serves as a handbook for the installation and application of the program. (orig.)

  3. ROXIE: Routine for the optimization of magnet X-sections, inverse field calculation and coil end design. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Russenschuck, S [ed.

    1999-04-12

    The Large Hadron Collider (LHC) will provide proton-proton collisions with a center-of-mass energy of 14 TeV which requires high field superconducting magnets to guide the counter-rotating beams in the existing LEP tunnel with a circumference of about 27 km. The LHC magnet system consists of 1232 superconducting dipoles and 386 main quadrupoles together with about 20 different types of magnets for insertions and correction. The design and optimization of these magnets is dominated by the requirement of a extremely uniform field which is mainly defined by the layout of the superconducting coils. The program package ROXIE (Routine for the Optimization of magnet X-sections, Inverse field calculation and coil End design) has been developed for the design and optimization of the coil geometries in two and three dimensions. Recently it has been extended in a collaboration with the University of Graz, Austria, to the calculation of saturation induced effects using a reduced vector-potential FEM formulation. With the University of Stuttgart, Germany, a collaboration exists fro the application of the BEM-FEM coupling method for the 2D and 3D field calculation. ROXIE now also features a TCL-TK user interface. The growing number of ROXIE users inside and outside CERN gave rise to the idea of organizing the 'First International ROXIE Users Meeting and Workshop' at CERN, March 16-18, 1998 which brought together about 50 researchers in the field. This report contains the contributions to the workshop and describes the features of the program, the mathematical optimization techniques applied and gives examples of the recent design work carried out. It also gives the theoretical background for the field computation methods and serves as a handbook for the installation and application of the program. (orig.)

  4. Highly reliable field electron emitters produced from reproducible damage-free carbon nanotube composite pastes with optimal inorganic fillers

    Science.gov (United States)

    Kim, Jae-Woo; Jeong, Jin-Woo; Kang, Jun-Tae; Choi, Sungyoul; Ahn, Seungjoon; Song, Yoon-Ho

    2014-02-01

    Highly reliable field electron emitters were developed using a formulation for reproducible damage-free carbon nanotube (CNT) composite pastes with optimal inorganic fillers and a ball-milling method. We carefully controlled the ball-milling sequence and time to avoid any damage to the CNTs, which incorporated fillers that were fully dispersed as paste constituents. The field electron emitters fabricated by printing the CNT pastes were found to exhibit almost perfect adhesion of the CNT emitters to the cathode, along with good uniformity and reproducibility. A high field enhancement factor of around 10 000 was achieved from the CNT field emitters developed. By selecting nano-sized metal alloys and oxides and using the same formulation sequence, we also developed reliable field emitters that could survive high-temperature post processing. These field emitters had high durability to post vacuum annealing at 950 °C, guaranteeing survival of the brazing process used in the sealing of field emission x-ray tubes. We evaluated the field emitters in a triode configuration in the harsh environment of a tiny vacuum-sealed vessel and observed very reliable operation for 30 h at a high current density of 350 mA cm-2. The CNT pastes and related field emitters that were developed could be usefully applied in reliable field emission devices.

  5. Systematic optimization of exterior measurement locations for the determination of interior magnetic field vector components in inaccessible regions

    Energy Technology Data Exchange (ETDEWEB)

    Nouri, N.; Plaster, B.

    2014-12-11

    An experiment may face the challenge of real-time determination of the magnetic field vector components present within some interior region of the experimental apparatus over which it is impossible to directly measure the field components during the operation of the experiment. As a solution to this problem, we propose a general concept which provides for a unique determination of the field components within such an interior region solely from exterior measurements at fixed discrete locations. The method is general and does not require the field to possess any type of symmetry. We describe our systematic approach for optimizing the locations of these exterior measurements which maximizes their sensitivity to successive terms in a multipole expansion of the field.

  6. Design of the Precipitation Process for Ni-Al Alloys with Optimal Mechanical Properties: A Phase-Field Study

    Science.gov (United States)

    Ta, Na; Zhang, Lijun; Du, Yong

    2014-04-01

    An attempt to design the heat treatment schedule for binary Ni-Al alloys with optimal mechanical properties was made in the present work. A series of quantitative three-dimensional (3-D) phase-field simulations of microstructure evolution in Ni-Al alloys during the precipitation process were first performed using MICRESS (MICRostructure Evolution Simulation Software) package developed in the formalism of the multi-phase field model. The coupling to CALPHAD (CALculation of PHAse Diagram) thermodynamic and atomic mobility databases was realized via TQ interface. Moreover, the temperature-dependent lattice misfits and elastic constants were utilized for simulation. The effect of the alloy composition and aging temperature on microstructure evolution was extensively studied with the aid of statistical analysis. After that, an evaluation function was proposed for evaluating the optimal heat treatment schedule by choosing the phase fraction, grain size, and shape factor of γ' precipitate as the evaluation indicators. Based on 50 groups of phase-field-simulated and experimental microstructure information, as well as the proposed evaluation function, the optimal alloy composition, aging temperature, and aging time for binary Ni-Al alloy with optimal mechanical properties were finally chosen. The successful application in the present Ni-Al alloys indicates that it is possible to design the optimal alloy composition and heat treatment for other binary and even multicomponent alloys with optimal mechanical properties based on the evaluation function and the sufficient microstructure information. Additionally, the combination of the present method and the key experiments can definitely accelerate the material design and improve the efficiency and accuracy.

  7. ROAM: A Radial-Basis-Function Optimization Approximation Method for Diagnosing the Three-Dimensional Coronal Magnetic Field

    International Nuclear Information System (INIS)

    Dalmasse, Kevin; Nychka, Douglas W.; Gibson, Sarah E.; Fan, Yuhong; Flyer, Natasha

    2016-01-01

    The Coronal Multichannel Polarimeter (CoMP) routinely performs coronal polarimetric measurements using the Fe XIII 10747 and 10798 lines, which are sensitive to the coronal magnetic field. However, inverting such polarimetric measurements into magnetic field data is a difficult task because the corona is optically thin at these wavelengths and the observed signal is therefore the integrated emission of all the plasma along the line of sight. To overcome this difficulty, we take on a new approach that combines a parameterized 3D magnetic field model with forward modeling of the polarization signal. For that purpose, we develop a new, fast and efficient, optimization method for model-data fitting: the Radial-basis-functions Optimization Approximation Method (ROAM). Model-data fitting is achieved by optimizing a user-specified log-likelihood function that quantifies the differences between the observed polarization signal and its synthetic/predicted analog. Speed and efficiency are obtained by combining sparse evaluation of the magnetic model with radial-basis-function (RBF) decomposition of the log-likelihood function. The RBF decomposition provides an analytical expression for the log-likelihood function that is used to inexpensively estimate the set of parameter values optimizing it. We test and validate ROAM on a synthetic test bed of a coronal magnetic flux rope and show that it performs well with a significantly sparse sample of the parameter space. We conclude that our optimization method is well-suited for fast and efficient model-data fitting and can be exploited for converting coronal polarimetric measurements, such as the ones provided by CoMP, into coronal magnetic field data.

  8. Optimization of microwave assisted digestion procedure for the determination of zinc, copper and nickel in tea samples employing flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Soylak, Mustafa; Tuzen, Mustafa; Souza, Anderson Santos; Korn, Maria das Gracas Andrade; Ferreira, Sergio Luis Costa

    2007-01-01

    The present paper describes the development of a microwave assisted digestion procedure for the determination of zinc, copper and nickel in tea samples employing flame atomic absorption spectrometry (FAAS). The optimization step was performed using a full factorial design (2 3 ) involving the factors: composition of the acid mixture (CMA), microwave power (MP) and radiation time (RT). The experiments of this factorial were carried out using a certified reference material of tea GBW 07605 furnished by National Research Centre for Certified Reference Materials, China, being the metal recoveries considered as response. The relative standard deviations of the method were found below 8% for the three elements. The procedure proposed was used for the determination of copper, zinc and nickel in several samples of tea from Turkey. For 10 tea samples analyzed, the concentration achieved for copper, zinc and nickel varied at 6.4-13.1, 7.0-16.5 and 3.1-5.7 (μg g -1 ), respectively

  9. Optimal usage of cone beam computed tomography system with different field of views in image guided radiotherapy (IGRT

    Directory of Open Access Journals (Sweden)

    Narayana Venkata Naga Madhusudhana Sresty

    2015-09-01

    Full Text Available Purpose: To find methods for optimal usage of XVI (X-ray volume imaging system in Elekta synergy linear accelerator with different field of views for same lesion in order to minimize patient dose due to imaging.Methods: 20 scans of 2 individual patients with ca sigmoid colon and ca lung were used in this study. Kilo voltage collimators with medium field of view were used as per the preset information. Images were reconstructed for another collimator with small field of view. The set up errors were evaluated with XVI software. Shift results of both methods were compared. Results: Variation in treatment set up errors with M20 and S20 collimators were ≤ 0.2 mm in translational and 0.30 in rotational shifts. Results showed almost equal translational and rotational shifts in both medium and small field of views with different collimators in all the scans. Visualization of target and surrounding structures were good enough and sufficient for XVI auto matching.Conclusion: Imaging with small field of view results less patient dose compared with medium or large field of views. It is Suggestible to use collimators with small field of view wherever possible. In this study, collimators with small field of view were sufficient for both patients though the preset information indicated medium field of view. But, it always depends on the area required for matching purpose. So, individual selection is important than preset information in the XVI system.

  10. A model for the value of a business, some optimization problems in its operating procedures and the valuation of its debt

    Science.gov (United States)

    1997-12-01

    In this paper we present a model for the value of a firm based on observable variables and parameters: the annual turnover, the expenses, interest rates. This value is the solution of a parabolic partial differential equation. We show how the value of the company depends on its legal status such as its liability (that is, whether it is a Limited Company or a sole trader/partnership). We give examples of how the operating procedures can be optimized (for example, whether the firm should close down, relocate etc.). Finally, we show how the model can be used to value the debt issued by the firm.

  11. Multivariate optimization of an ultrasound-assisted extraction procedure for Cu, Mn, Ni and Zn determination in ration to chickens

    Directory of Open Access Journals (Sweden)

    JOELIA M. BARROS

    2013-09-01

    Full Text Available In this work, multivariate optimization techniques were used to develop a method based on the ultrasound-assisted extraction for copper, manganese, nickel and zinc determination from rations for chicken nutrition using flame atomic absorption spectrometry. The proportions of extracting components (2.0 mol.L–1 nitric, hydrochloric and acetic acid solutions were optimized using centroid-simplex mixture design. The optimum proportions of this mixture taken as percentage of each component were respectively 20%, 37% and 43%. Variables of method (sample mass, sonication time and final acid concentration were optimized using Doehlert design. The optimum values found for these variables were respectively 0.24 g, 18s and 3.6 mol.L–1. The developed method allows copper, manganese, nickel and zinc determination with quantification limits of 2.82; 4.52; 10.7; e 9.69 µg.g–1, and precision expressed as relative standard deviation (%RSD, 25 µg.g–1, N = 5 of 5.30; 2.13; 0.88; and 0.83%, respectively. This method was applied in the analytes determination from chicken rations collected from specialized commerce in Jequié city (Bahia State/Brazil. Application of paired t-test at the obtained results, in a confidence level of 95%, does not show significant difference between the proposed method and the microwave-assisted digestion.

  12. The optimization of acoustic fields for ablative therapies of tumours in the upper abdomen

    Science.gov (United States)

    Gélat, P.; ter Haar, G.; Saffari, N.

    2012-12-01

    High intensity focused ultrasound (HIFU) enables highly localized, non-invasive tissue ablation and its efficacy has been demonstrated in the treatment of a range of cancers, including those of the kidney, prostate and breast. HIFU offers the ability to treat deep-seated tumours locally, and potentially bears fewer side effects than more invasive treatment modalities such as resection, chemotherapy and ionizing radiation. There remains however a number of significant challenges which currently hinder its widespread clinical application. One of these challenges is the need to transmit sufficient energy through the ribcage to ablate tissue at the required foci whilst minimizing the formation of side lobes and sparing healthy tissue. Ribs both absorb and reflect ultrasound strongly. This sometimes results in overheating of bone and overlying tissue during treatment, leading to skin burns. Successful treatment of a patient with tumours in the upper abdomen therefore requires a thorough understanding of the way acoustic and thermal energy is deposited. Previously, a boundary element approach based on a Generalized Minimal Residual (GMRES) implementation of the Burton-Miller formulation was developed to predict the field of a multi-element HIFU array scattered by human ribs, the topology of which was obtained from CT scan data (Gélat et al 2011 Phys. Med. Biol. 56 5553-81). The present paper describes the reformulation of the boundary element equations as a least-squares minimization problem with nonlinear constraints. The methodology has subsequently been tested at an excitation frequency of 1 MHz on a spherical multi-element array in the presence of ribs. A single array-rib geometry was investigated on which a 50% reduction in the maximum acoustic pressure magnitude on the surface of the ribs was achieved with only a 4% reduction in the peak focal pressure compared to the spherical focusing case. This method was then compared with a binarized apodization approach

  13. Field-based optimal-design of an electric motor: a new sensitivity formulation

    Science.gov (United States)

    Barba, Paolo Di; Mognaschi, Maria Evelina; Lowther, David Alister; Wiak, Sławomir

    2017-12-01

    In this paper, a new approach to robust optimal design is proposed. The idea is to consider the sensitivity by means of two auxiliary criteria A and D, related to the magnitude and isotropy of the sensitivity, respectively. The optimal design of a switched-reluctance motor is considered as a case study: since the case study exhibits two design criteria, the relevant Pareto front is approximated by means of evolutionary computing.

  14. Optimization of the radiation protection in industrial field: study of some practical cases

    International Nuclear Information System (INIS)

    Muglioni, P.

    1998-01-01

    Two situations are studied: the case of stationary gauges where the situation is sure with little actions to do to optimize the radiation protection and the case of mobile sources where the sources can submit to important exposure. In these conditions, the best way to optimize the radiation protection is to integrate the constraints, to put in operation a dosimetry and to keep a correct level of radiation protection information. (N.C.)

  15. Establishing personal dosimetry procedure using optically stimulated luminescence dosimeters in photon and mixed photon-neutron radiation fields

    International Nuclear Information System (INIS)

    Le Ngoc Thiem; Bui Duc Ky; Trinh Van Giap; Nguyen Huu Quyet; Ho Quang Tuan; Vu Manh Khoi; Chu Vu Long

    2017-01-01

    According to Vietnamese Law on Atomic Energy, personal dosimetry (PD) for radiation workers is required periodically in order to fulfil the national legal requirements on occupational radiation dose management. Since the radiation applications have become popular in Vietnamese society, the thermal luminescence dosimeters (TLDs) have been used as passive dosimeters for occupational monitoring in the nation. Together with the quick increase in radiation applications and the number of personnel working in radiation fields, the Optically Stimulated Luminescence Dosimeters (OSLDs) have been first introduced since 2015. This work presents the establishment of PD measuring procedure using OSLDs which are used for measuring photons and betas known as Inlight model 2 OSL (OSLDs-p,e) and for measuring mixed radiations of neutrons, photons and betas known as Inlight LDR model 2 (OSLDs-n,p,e). Such following features of OSLDs are investigated: detection limit, energy response, linearity, reproducibility, angular dependency and fading with both types of OSLDs-p,e and OSLDs-n,p,e. The result of an intercomparison in PD using OSLDs is also presented in the work. The research work also indicates that OSL dosimetry can be an alternative method applied in PD and possibly become one of the most popular personal dosimetry method in the future. (author)

  16. SOME REMARKS ON THE RELATION OF FORMAL AND INFORMAL IN SOLVING OPTIMIZATION PROBLEMS IN THE FIELD OF AVIATION SECURITY

    Directory of Open Access Journals (Sweden)

    L. N. Elisov

    2015-01-01

    Full Text Available The paper presents the authors view and some remarks on the problem of solving optimization problems in the field of aviation security related to insurmountable difficulties of formalization and mathematical interpretation of the domain formulation of such problems. It is shown that the vast majority of these problems is related to the solution of conflicts. The theory of conflicts gives analytical solution only in the simplest cases. For the rest the use of a heuristic approach is suggested.

  17. HASL procedures manual

    International Nuclear Information System (INIS)

    Harley, J.H.

    1977-08-01

    Additions and corrections to the following sections of the HASL Procedures Manual are provided: General, Sampling, Field Measurements; General Analytical Chemistry, Chemical Procedures, Data Section, and Specifications

  18. Tadalafil inclusion in microporous silica as effective dissolution enhancer: optimization of loading procedure and molecular state characterization.

    Science.gov (United States)

    Mehanna, Mohammed M; Motawaa, Adel M; Samaha, Magda W

    2011-05-01

    Tadalafil is an efficient drug used to treat erectile dysfunction characterized by poor water solubility, which has a negative influence on its bioavailability. Utilization of microporous silica represents an effective and facile technology to increase the dissolution rate of poorly soluble drugs. Our strategy involved directly introducing tadalafil as guest molecule into microporous silica as host material by incipient wetness impregnation method. To optimize tadalafil inclusion, response surface methodology (RSM) using 3(3) factorial design was utilized. Furthermore, to investigate the molecular state of tadalafil, Fourier-transform infrared spectroscopy, differential scanning calorimetery, thermal gravimetrical analysis, nitrogen adsorption, and powder X-ray diffraction (PXRD) were carried out. The results obtained pointed out that the quantity of microporous silica was the predominant factor that increased the loading efficiency. For the optimized formula, the loading efficiency was 42.50 wt %. Adsorption-desorption experiments indicated that tadalafil has been introduced into the micropores. Powder XRD and differential scanning calorimetry analyses revealed that tadalafil is arranged in amorphous form. In addition, the dissolution rate of tadalafil from the microporous silica was faster than that of free drug. Amorphous tadalafil occluded in microporous silica did not crystallize over 3 months. These findings contributed in opening a new strategy concerning the utilization of porous silica for the dissolution rate enhancement. Copyright © 2010 Wiley-Liss, Inc.

  19. Multi-objective optimization of the management of a waterworks using an integrated well field model

    DEFF Research Database (Denmark)

    Hansen, Annette Kirstine; Bauer-Gottwein, Peter; Rosbjerg, Dan

    2012-01-01

    of predicting the water level and the energy consumption of the individual production wells. The model has been applied to Søndersø waterworks in Denmark, where it predicts the energy consumption within 1.8% of the observed. The objectives of the optimization problem are to minimize the specific energy...... provides the decision-makers with compromise solutions between the two competing objectives. In the test case the Pareto optimal solutions are compared with an exhaustive benchmark solution. It is shown that the energy consumption can be reduced by 4% by changing the pumping configuration without violating...

  20. Optimizing Global Coronal Magnetic Field Models Using Image-Based Constraints

    Science.gov (United States)

    Jones-Mecholsky, Shaela I.; Davila, Joseph M.; Uritskiy, Vadim

    2016-01-01

    The coronal magnetic field directly or indirectly affects a majority of the phenomena studied in the heliosphere. It provides energy for coronal heating, controls the release of coronal mass ejections, and drives heliospheric and magnetospheric activity, yet the coronal magnetic field itself has proven difficult to measure. This difficulty has prompted a decades-long effort to develop accurate, timely, models of the field, an effort that continues today. We have developed a method for improving global coronal magnetic field models by incorporating the type of morphological constraints that could be derived from coronal images. Here we report promising initial tests of this approach on two theoretical problems, and discuss opportunities for application.

  1. Optimization of Radiological Protection in Pediatric Patients Undergoing Common Conventional Radiological Procedures: Effectiveness of Increasing the Film to Focus Distance (FFD

    Directory of Open Access Journals (Sweden)

    Vahid Karami

    2017-04-01

    Full Text Available Background Increasing the x-ray film to focus distance (FFD, has been recommended as a practical dose optimization tool for patients undergoing conventional radiological procedures. In the previous study, we demonstrated a 32% reduction in absorbed dose is achievable due to increasing the FFD from 100 to 130 cm during pediatric chest radiography. The aim of this study was to examine whether increasing the FFD from 100 to 130 cm is equally effective for other common radiological procedures and performing a literature review of published studies to address the feasibility and probable limitations against implementing this optimization tool in clinical practice. Materials and Methods Radiographic examination of the pelvis (AP view, abdomen (AP view, skull (AP and lateral view, and spine (AP and lateral view, were taken of pediatric patients. The radiation dose and image quality of a radiological procedure is measured in FFD of 100 cm (reference FFD and 130 cm (increased FFD. The thermo-luminescent dosimeters (TLD were used for radiation dose measurements and visual grading analysis (VGA for image quality assessments. Results: Statistically significant reduction in the ESD ranged from 21.91% for the lateral skull projection to 35.24% for the lateral spine projection was obtained, when the FFD was increased from 100 to 130 cm (P0.05. Conclusion Increasing the FFD from 100 to 130 cm has significantly reduced radiation exposure without affecting on image quality. Our findings are commensurate with the literatures and emphasized that radiographers should learn to use of an updated reference FFD of 130 cm in clinical practice.

  2. On developing an optimal design procedure for a bimorph piezoelectric cantilever energy harvester under a predefined volume

    Science.gov (United States)

    Aboulfotoh, Noha; Twiefel, Jens

    2018-06-01

    A typical vibration harvester is tuned to operate at resonance in order to maximize the power output. There are many design parameter sets for tuning the harvester to a specific frequency, even for simple geometries. This work studies the impact of the geometrical parameters on the harvested power while keeping the resonance frequency constant in order to find the combination of the parameters that optimizes the power under a predefined volume. A bimorph piezoelectric cantilever is considered for the study. It consists of two piezoelectric layers and a middle non-piezoelectric layer and holds a tip mass. A theoretical model was derived to obtain the system parameters and the power as functions of the design parameters. Formulas for the optimal load resistance that provide maximum power capability at resonance and anti-resonance frequency were derived. The influence of the width on the power is studied, considering a constant mass ratio (between the tip mass and the mass of the beam). This keeps the resonance frequency constant while changing the width. The influence of the ratio between the thickness of the middle layer and that of the piezoelectric layer is also studied. It is assumed that the total thickness of the cantilever is constant and the middle layer has the same mechanical properties (elasticity and density) as the piezoelectric layer. This keeps the resonance frequency constant while changing the ratio between the thicknesses. Finally, the influence of increasing the free length as well as of increasing the mass ratio on the power is investigated. This is done by first, increasing each of them individually and secondly, by increasing each of them simultaneously while increasing the total thickness under the condition of maintaining a constant resonance frequency. Based on the analysis of these influences, recommendations as to how to maximize the geometrical parameters within the available volume and mass are presented.

  3. Administrative environmental proceedings in the electromagnetic pollution field; Procedure autorizzatorie nel settore dell'inquinamento da campi elettromagnetici

    Energy Technology Data Exchange (ETDEWEB)

    Fracchia, Fabrizio [Bocconi Univ., Milano (Italy). IDC Istituto di diritto comparato

    2005-05-15

    The aim of the research at issue is to understand the general aspects of administrative environmental proceedings in the electromagnetic pollution field, as they are regulated in Italy both by the Law of February 22, 2001, No. 36 and by the art. 87 of the Legislative Decree of August 1, 2003, No. 259 (by means of this decree, Italy implemented a package of EU Directives -2002/19/EC, 2002/20/EC, 2002/21/EC and 2002/22/EC - in the TLC sector; entered into force on September 16, 2003, it introduced the so-called Unique Code on Electronic Communications) [Italian] Il lavoro ha ad oggetto l'analisi delle procedure autorizzatorie nel settore dell'inquinamento da campi elettromagnetici disciplinate dalla legge 22 febbraio 2001, n. 36 e dall'art. 87, d.lgs. 1 agosto 2003, n. 259 (codice delle comunicazioni elettroniche). Dopo aver registrato la presenza, all'interno di siffatti procedimenti, delle tradizionali funzioni assegnate al procedimento amministrativo, l'indagine individua nel dettaglio i principi stabiliti dalla normativa e i caratteri dell'autorizzazione, indugiando in particolare sul profilo del margine di discrezionalita sussistente in capo all'amministrazione. L'angustia di questo spazio di discrezionalita viene tra l'altro collegato alla rilevanza che, nel settore in esame, risulta avere il principio di precauzione. Specifica attenzione e dedicata al procedimento delineato dall'art. 87, d.lgs. 259/2003, cit.: vengono analizzati i titoli di legittimazione ivi disciplinati, i rapporti con l'istituto della valutazione di impatto ambientale, le fasi procedimentali, la conferenza di servizi e i limiti di applicabilita del meccanismo del silenzio assenso, il tutto avendo come riferimento essenziale il tema della precauzione, il principio di doverosita e la loro valenza normativa.

  4. Development and evaluation of accessories to improve the posture of veterinary surgeons in surgical procedures conducted in the field

    Directory of Open Access Journals (Sweden)

    V.A.S. Vulcani

    Full Text Available ABSTRACT The study was conducted based on the information collected on rural properties in the state of Goiás, during practical classes of Surgical Clinic in Large Animals at the Veterinary Hospital of the Escola de Veterinária e Zootecnia of the Universidade Federal de Goiás and during the implementation of outreach projects developed by the institution. An acropostite-phimosis surgical procedure in the bulls in the field was selected, lasting over 30 minutes and requiring movements, posture and strength on the part of the surgeon. Devices were proposed and developed to provide improved comfort and safety to surgeons. The first device was a stool to be used by the professional during the execution of the surgical intervention. The use enabled the surgeon to sit down and rest their feet on the ground, reducing knee bending and distributing the support forces in various muscle groups. For the movement restriction of the surgeon, another accessory was developed to support the foreskin of the animal. Made of wood, this other device serves as a support for keeping the foreskin away from the ground and close to the surgeon. Its length, width and thickness established a good relation with the stool height, providing minimal discomfort to the professional. The third device was designed to assist in the immobilization of the animal and increase safety for the patient and surgical team. A fourth accessory was designed to protect the scapular region and avoid the occurrence of injuries in the radial nerve, myopathies and traumas during the rollover or prolonged stay of the animal in lateral decubitus. The choice of the shape, dimensions and softness of the device was mainly based on the weight of the animal. Such devices have proven to be effective, reducing the time of surgery, making cervical and lumbar movement easier, in addition to providing better support to the surgeon, reducing risks of musculoskeletal diseases.

  5. An optimized groundwater extraction system for the toxic burning pits area of J-Field, Aberdeen Proving Ground, Maryland

    Energy Technology Data Exchange (ETDEWEB)

    Quinn, J.J.; Johnson, R.L.; Patton, T.L.; Martino, L.E.

    1996-06-01

    Testing and disposal of chemical warfare agents, munitions, and industrial chemicals at the J-Field area of the Aberdeen Proving Ground (APG) have resulted in contamination of soil and groundwater. The discharge of contaminated groundwater to on-site marshes and adjacent estuaries poses a potential risk to ecological receptors. The Toxic Burning Pits (TBP) area is of special concern because of its disposal history. This report describes a groundwater modeling study conducted at J-Field that focused on the TBP area. The goal of this modeling effort was optimization of the groundwater extraction system at the TBP area by applying linear programming techniques. Initially, the flow field in the J-Field vicinity was characterized with a three-dimensional model that uses existing data and several numerical techniques. A user-specified border was set near the marsh and used as a constraint boundary in two modeled remediation scenarios: containment of the groundwater and containment of groundwater with an impermeable cap installed over the TBP area. In both cases, the objective was to extract the minimum amount of water necessary while satisfying the constraints. The smallest number of wells necessary was then determined for each case. This optimization approach provided two benefits: cost savings, in that the water to be treated and the well installation costs were minimized, and minimization of remediation impacts on the ecology of the marsh.

  6. Optimization of the workers radiation protection in the electro nuclear, industrial and medical fields

    International Nuclear Information System (INIS)

    1998-01-01

    This conference is devoted to the radiation protection and the best way to optimize it. It reviews each area of the nuclear industry, and explores also the medical sector. Dosimetry, ALARA principle and new regulation are important points of this meeting. (N.C.)

  7. Crowded Field Photometry and Moving Object Detection with Optimal Image Subtraction

    Science.gov (United States)

    Lee, Austin A. T.; Scheulen, F.; Sauro, C. M.; McMahon, C. T.; Berry, S. J.; Robinson, C. H.; Buie, M. W.; Little, P.

    2010-05-01

    High precision photometry and moving object detection are essential in the study of Pluto and the Kuiper Belt. In particular, the New Horizons mission would benefit from an accurate and fast method of performing image subtraction to locate faint Kuiper Belt Objects (KBO) among large data sets. The optimal image subtraction (OIS) algorithm was optimized for IDL to decrease execution time by a factor of about 140 from a previous implementation (Miller 2008, PASP, 120, 449). In addition, a powerful image transformation and interpolation routine was written to provide OIS with well-aligned input images using astrometric fit data. The first half of this project is complete including the code optimization and the alignment routine. The second half of the project is focused on using these tools to search a 5 x 10 degree search area to find KBOs for possible targets for the New Horizons mission. We will present examples of how these tools work and along with resulting Pluto photometry and KBO target lists. The optimized OIS and transformation routines are available in Marc Buie's IDL library at http://www.boulder.swri.edu/ buie/idl/ as ois.pro and dewarp.pro. This project was conducted for Harvey Mudd College's Clinic Program with financial support from the NASA Planetary Astronomy Program grant number NNX09AB43G.

  8. Optimization of s-Polarization Sensitivity in Apertureless Near-Field Optical Microscopy

    Directory of Open Access Journals (Sweden)

    Yuika Saito

    2012-01-01

    Full Text Available It is a general belief in apertureless near-field microscopy that the so-called p-polarization configuration, where the incident light is polarized parallel to the axis of the probe, is advantageous to its counterpart, the s-polarization configuration, where the incident light is polarized perpendicular to the probe axis. While this is true for most samples under common near-field experimental conditions, there are samples which respond better to the s-polarization configuration due to their orientations. Indeed, there have been several reports that have discussed such samples. This leads us to an important requirement that the near-field experimental setup should be equipped with proper sensitivity for measurements with s-polarization configuration. This requires not only creation of effective s-polarized illumination at the near-field probe, but also proper enhancement of s-polarized light by the probe. In this paper, we have examined the s-polarization enhancement sensitivity of near-field probes by measuring and evaluating the near-field Rayleigh scattering images constructed by a variety of probes. We found that the s-polarization enhancement sensitivity strongly depends on the sharpness of the apex of near-field probes. We have discussed the efficient value of probe sharpness by considering a balance between the enhancement and the spatial resolution, both of which are essential requirements of apertureless near-field microscopy.

  9. MO-AB-BRA-08: Rapid Treatment Field Uniformity Optimization for Total Skin Electron Beam Therapy Using Cherenkov Imaging

    International Nuclear Information System (INIS)

    Andreozzi, J; Zhang, R; Glaser, A; Pogue, B; Jarvis, L; Williams, B; Gladstone, D

    2015-01-01

    Purpose: To evaluate treatment field heterogeneity resulting from gantry angle choice in total skin electron beam therapy (TSEBT) following a modified Stanford dual-field technique, and determine a relationship between source to surface distance (SSD) and optimized gantry angle spread. Methods: Cherenkov imaging was used to image 62 treatment fields on a sheet of 1.2m x 2.2m x 1.2cm polyethylene following standard TSEBT setup at our institution (6 MeV, 888 MU/min, no spoiler, SSD=441cm), where gantry angles spanned from 239.5° to 300.5° at 1° increments. Average Cherenkov intensity and coefficient of variation in the region of interest were compared for the set of composite Cherenkov images created by summing all unique combinations of angle pairs to simulate dual-field treatment. The angle pair which produced the lowest coefficient of variation was further studied using an ionization chamber. The experiment was repeated at SSD=300cm, and SSD=370.5cm. Cherenkov imaging was also implemented during TSEBT of three patients. Results: The most uniform treatment region from a symmetric angle spread was achieved using gantry angles +/−17.5° about the horizontal axis at SSD=441cm, +/−18.5° at SSD=370.5cm, and +/−19.5° at SSD=300cm. Ionization chamber measurements comparing the original treatment spread (+/−14.5°) and the optimized angle pair (+/−17.5°) at SSD=441cm showed no significant deviation (r=0.999) in percent depth dose curves, and chamber measurements from nine locations within the field showed an improvement in dose uniformity from 24.41% to 9.75%. Ionization chamber measurements correlated strongly (r=0.981) with Cherenkov intensity measured concurrently on the flat Plastic Water phantom. Patient images and TLD results also showed modest uniformity improvements. Conclusion: A decreasing linear relationship between optimal angle spread and SSD was observed. Cherenkov imaging offers a new method of rapidly analyzing and optimizing TSEBT setup

  10. Optimization and Optimal Control

    CERN Document Server

    Chinchuluun, Altannar; Enkhbat, Rentsen; Tseveendorj, Ider

    2010-01-01

    During the last four decades there has been a remarkable development in optimization and optimal control. Due to its wide variety of applications, many scientists and researchers have paid attention to fields of optimization and optimal control. A huge number of new theoretical, algorithmic, and computational results have been observed in the last few years. This book gives the latest advances, and due to the rapid development of these fields, there are no other recent publications on the same topics. Key features: Provides a collection of selected contributions giving a state-of-the-art accou

  11. Optimizing the field distribution of a Halbach type permanent magnet cylinder using the soft iron and superhard magnet

    Science.gov (United States)

    Xu, Xiaonong; Lu, Dingwei; Xu, Xibin; Yu, Yang; Gu, Min

    2018-01-01

    When a conventional Halbach type Hollow Cylindrical Permanent Magnet Array (HCPMA) is used to generate magnetic induction over the magnitude of coercivity μ0Hc, some detrimental parasitic magnetic phenomena, such as the demagnetization, magnetization reversal, and vortexes of magnetization, can appear in the interior of the magnets. We present a self-consistent quantitative analysis of the magnetization and magnetic induction distributions inside the magnetic array by considering the anisotropic and nonlinear magnetization functions of the materials consisting of the array. These numeric simulations reveal novel magnetization structures resulted from the self-field of array. We demonstrate that both the field uniformity and magnetic flux in the pole gap can be modulated by partially substituting the magnets of high energy products with the soft irons and the superhard magnets. We also show how the optimized substitution parameters can be obtained for a HCPMA achieving the best field uniformity or the maximum magnetic flux.

  12. On finding the analytic dependencies of the external field potential on the control function when optimizing the beam dynamics

    Science.gov (United States)

    Ovsyannikov, A. D.; Kozynchenko, S. A.; Kozynchenko, V. A.

    2017-12-01

    When developing a particle accelerator for generating the high-precision beams, the injection system design is of importance, because it largely determines the output characteristics of the beam. At the present paper we consider the injection systems consisting of electrodes with given potentials. The design of such systems requires carrying out simulation of beam dynamics in the electrostatic fields. For external field simulation we use the new approach, proposed by A.D. Ovsyannikov, which is based on analytical approximations, or finite difference method, taking into account the real geometry of the injection system. The software designed for solving the problems of beam dynamics simulation and optimization in the injection system for non-relativistic beams has been developed. Both beam dynamics and electric field simulations in the injection system which use analytical approach and finite difference method have been made and the results presented in this paper.

  13. Optimization of synthesis and quality control procedures for the preparations of 18F and 123I labelled peptides

    International Nuclear Information System (INIS)

    Archimandritis, S.C.; Potamianos, S.; Varvarigou, A.D.

    2002-01-01

    Radiolabelled biomolecules like proteins and peptides, are playing now days an important role in experimental and clinical Nuclear Medicine. Radioiodination techniques remain important, with improvements accounting for high purity, specific activity and better in vivo stability. Radioiodination using prosthetic groups is the method of choice in cases where the molecules are lacking of thyrosyl groups in their structure and are also sensitive to circulating dehalogenase enzymes. This investigation was based on the need to optimize labelling and quality control techniques for these molecules. The N-succinimidyliodobenzoate (SIB) was used in this study as the prosthetic group for the radioiodination. Optimization of SIB synthesis and modification of the protocol resulted in an improved mean yield of SIB. The combination of TLC and column chromatography using silica gel proved suitable in identifying SIB. Furthermore, the ability of SIB to couple to protein was also used to confirm the presence of SIB. In this case, SEC and ITLC-SG proved suitable to confirm protein binding of SIB. Column chromatography using silica gel containing Sep-Pak was appropriate for SIB purification. Concerning SIB conjugation to peptides, high radioiodination yields were only possible for peptides with amino-containing-side-chain amino acids. Furthermore, lysine containing peptides retained stability, at 4 deg. C, for at least 24 h and reverse phase HPLC proved the most suitable technique for assessing conjugation of SIB to peptide. The biological evaluation of the radiolabelled product was made in normal mice. SIB and SIB-peptide conjugates were tested comparatively and a number of tentative but interesting inferences were drawn. SIB and its peptide conjugates exhibited good in vivo stability as evidenced by low thyroid accumulation and were cleared via the kidneys. A time dependant decrease in the% dose per gram of tissue indicates possible adrenal metabolism of SIB and SIB

  14. MATLAB-based program for optimization of quantum cascade laser active region parameters and calculation of output characteristics in magnetic field

    Science.gov (United States)

    Smiljanić, J.; Žeželj, M.; Milanović, V.; Radovanović, J.; Stanković, I.

    2014-03-01

    supporting MATLAB version R2010a or higher. RAM: Minimum required is 1 GB. Memory usage increases for less intense magnetic fields. Classification: 15. Nature of problem: The nature of the problem is to provide an efficient numerical algorithm implementation for optimization of GaAs/AlGaAs QCL active region parameters and calculation of output properties in the magnetic field. Solution method: The optimization of the QCL laser performance at selected wavelength is performed at entire free-parameters space using simulated annealing algorithm. The scattering rates are calculated in the presence and without magnetic field and used as coefficients in rate equations. The standard MATLAB procedures were used to solve iteratively this system of equations and obtain distribution of electron densities over electronic states. Restrictions: The machine must provide the necessary main memory which decreases roughly quadratically with the increase of the magnetic field intensity. Running time: Optimization time on Intel 3 GHz processor is about 2×104 s. The calculation time of laser output properties for values set automatically in GUI is 5×104 s.

  15. What is the optimal minimally invasive surgical procedure for endometrial cancer staging in the obese and morbidly obese woman?

    Science.gov (United States)

    Gehrig, Paola A; Cantrell, Leigh A; Shafer, Aaron; Abaid, Lisa N; Mendivil, Alberto; Boggess, John F

    2008-10-01

    Thirty-three percent of U.S. women are either obese or morbidly obese. This is associated with an increased risk of death from all causes and is also associated with an increased risk of endometrial carcinoma. We sought to compare minimally invasive surgical techniques for staging the obese and morbidly obese woman with endometrial cancer. Consecutive robotic endometrial cancer staging procedures were collected from 2005-2007 and were compared to consecutive laparoscopic cases (2000-2004). Demographics including age, weight, body mass index (BMI), operative time, estimated blood loss, lymph node retrieval, hospital stay and complications were collected and compared. During the study period, there were 36 obese and 13 morbidly obese women who underwent surgery with the DaVinci robotic system and 25 obese and 7 morbidly obese women who underwent traditional laparoscopy. For both the obese and morbidly obese patient, robotic surgery was associated with shorter operative time (p=0.0004), less blood loss (ptool for the comprehensive surgical staging of the obese and morbidly obese woman with endometrial cancer. As this patient population is at increased risk of death from all causes, including post-operative complications, all efforts should be made to improve their outcomes and minimally invasive surgery provides a useful platform by which this can occur.

  16. An optimal range of information quantity on computer-based procedure interface design in the advanced main control room

    International Nuclear Information System (INIS)

    Hsieh Minchih; Chiu Mingchuan; Hwang Sheueling

    2015-01-01

    The quantification of information in the interface design is a critical issue. Too much information on an interface can confuse a user while executing a task, and too little information may result in poor user performance. This study focused on the quantification of visible information on computer-based procedures (CBPs). Levels of information quantity and task complexity were considered in this experiment. Simulated CBPs were developed to consist of three levels: high (at least 10 events, i.e. 3.32 bits), medium (4–8 events, i.e. 2–3 bits), and low information quantity (1 or 2 events, i.e. 0 or 1 bits). Task complexity comprised two levels: complex tasks and simple tasks. The dependent variables include operation time, secondary task performance, and mental workload. Results suggested that medium information quantity of five to eight events has a remarkable advantage in supporting operator performance under both simple and complex tasks. This research not only suggested the appropriate range of information quantity on the CBP interface, but also complemented certain deficient results of previous CBP interface design studies. Additionally, based on results obtained by this study, the quantification of information on the CBP interface should be considered to ensure safe operation of nuclear power plants. (author)

  17. Optimization Correction Strength Using Contra Bending Technique without Anterior Release Procedure to Achieve Maximum Correction on Severe Adult Idiopathic Scoliosis

    Directory of Open Access Journals (Sweden)

    Ahmad Jabir Rahyussalim

    2016-01-01

    Full Text Available Adult scoliosis is defined as a spinal deformity in a skeletally mature patient with a Cobb angle of more than 10 degrees in the coronal plain. Posterior-only approach with rod and screw corrective manipulation to add strength of contra bending manipulation has correction achievement similar to that obtained by conventional combined anterior release and posterior approach. It also avoids the complications related to the thoracic approach. We reported a case of 25-year-old male adult idiopathic scoliosis with double curve. It consists of main thoracic curve of 150 degrees and lumbar curve of 89 degrees. His curve underwent direct contra bending posterior approach using rod and screw corrective manipulation technique to achieve optimal correction. After surgery the main thoracic Cobb angle becomes 83 degrees and lumbar Cobb angle becomes 40 degrees, with 5 days length of stay and less than 800 mL blood loss during surgery. There is no complaint at two months after surgery; he has already come back to normal activity with good functional activity.

  18. Selection of optimal treatment procedures for non-standard radioactive waste arising from decommissioning of NPP after accident

    Energy Technology Data Exchange (ETDEWEB)

    Strážovec, Roman, E-mail: strazovec.roman@javys.sk [Institute of Nuclear and Physical Engineering, Slovak University of Technology in Bratislava, Ilkovičova 3, 812 19 Bratislava (Slovakia); JAVYS, a.s., Tomášikova 22, 821 02 Bratislava (Slovakia); Hrnčíř, Tomáš [DECOM, a.s., Sibírska 1, 917 01 Trnava (Slovakia); Lištjak, Martin [Institute of Nuclear and Physical Engineering, Slovak University of Technology in Bratislava, Ilkovičova 3, 812 19 Bratislava (Slovakia); VUJE, a.s., Okružná 5, 918 64 Trnava (Slovakia); Nečas, Vladimír [Institute of Nuclear and Physical Engineering, Slovak University of Technology in Bratislava, Ilkovičova 3, 812 19 Bratislava (Slovakia)

    2016-05-15

    The decommissioning of nuclear power plants is becoming a standard industrial activity where the optimization processes of partial activities are inevitable mainly for technical and economic reasons. In Slovakia, the decommissioning of A1 NPP is very specific case because A1 NPP is rare type of NPP (prototype) and furthermore its operation was affected by the accident. A large number of specific non-standard radioactive waste, such as long-time storage cases (hereinafter LSC), that is not usually present within the decommissioning projects of NPP with a regular termination of operation, represent one of the significant consequences of the accident and issues arisen from follow-up activities. The presented article describes the proposal of processing and conditioning of non-standard radioactive waste (such as LSC), together with description of methodology applied in the proposal for update of waste acceptance criteria for the processing and conditioning of radioactive waste (hereinafter RAW) within Bohunice Radioactive waste Treatment and Conditioning Centre (hereinafter RWTC). The results of performed detailed analysis are summarized into new waste acceptance criteria for technological lines keeping in mind safety principles and requirements for protection of operating personnel, the public and the environment.

  19. The choice of optimal antireflux procedure after laparoscopic cardiomyotomy: two decades of clinical experience in one center.

    Science.gov (United States)

    Kiudelis, Mindaugas; Kubiliute, Egle; Sakalys, Egidijus; Jonaitis, Laimas; Mickevicius, Antanas; Endzinas, Zilvinas

    2017-09-01

    Two types of partial wrap are commonly performed in achalasia patients after Heller myotomy: the posterior 270° fundoplication (Toupet) and the anterior 180° fundoplication (Dor). The optimal type of fundoplication (posterior vs. anterior) is still debated. To compare the long-term rates of dysphagia, reflux symptoms and patient satisfaction with current postoperative condition between two fundoplication groups in achalasia treatment. Our retrospective study included 97 consecutive patients with achalasia: 37 patients underwent laparoscopic posterior Toupet (270°) fundoplication followed by Heller myotomy (group I); 60 patients underwent laparoscopic anterior partial Dor fundoplication followed by Heller myotomy (group II). Long-term follow-up results included evaluation of dysphagia symptoms, intensity of heartburn and patient satisfaction with current condition. Patients in these two groups did not differ according to age, weight, height, postoperative stay or follow-up period. Laparoscopic myotomy with posterior Toupet fundoplication was effective in 89% of patients, while laparoscopic myotomy with anterior Dor was effective in 93% of patients (p > 0.05). 11% of patients after posterior Toupet fundoplication had clinically significant heartburn vs. 35% of patients after anterior Dor fundoplication (p < 0.05). Overall patient satisfaction with current condition was 88%, with no significant difference between the groups. According to our study results, the two laparoscopic techniques were similarly effective in reducing achalasia symptoms, but postoperative clinical manifestation of heartburn is significantly more frequent after anterior Dor fundoplication (35% vs. 11%). The majority of patients (88%) were satisfied with operation outcomes.

  20. Two-speed phacoemulsification for soft cataracts using optimized parameters and procedure step toolbar with the CENTURION Vision System and Balanced Tip.

    Science.gov (United States)

    Davison, James A

    2015-01-01

    To present a cause of posterior capsule aspiration and a technique using optimized parameters to prevent it from happening when operating soft cataracts. A prospective list of posterior capsule aspiration cases was kept over 4,062 consecutive cases operated with the Alcon CENTURION machine and Balanced Tip. Video analysis of one case of posterior capsule aspiration was accomplished. A surgical technique was developed using empirically derived machine parameters and customized setting-selection procedure step toolbar to reduce the pace of aspiration of soft nuclear quadrants in order to prevent capsule aspiration. Two cases out of 3,238 experienced posterior capsule aspiration before use of the soft quadrant technique. Video analysis showed an attractive vortex effect with capsule aspiration occurring in 1/5 of a second. A soft quadrant removal setting was empirically derived which had a slower pace and seemed more controlled with no capsule aspiration occurring in the subsequent 824 cases. The setting featured simultaneous linear control from zero to preset maximums for: aspiration flow, 20 mL/min; and vacuum, 400 mmHg, with the addition of torsional tip amplitude up to 20% after the fluidic maximums were achieved. A new setting selection procedure step toolbar was created to increase intraoperative flexibility by providing instantaneous shifting between the soft and normal settings. A technique incorporating a reduced pace for soft quadrant acquisition and aspiration can be accomplished through the use of a dedicated setting of integrated machine parameters. Toolbar placement of the procedure button next to the normal setting procedure button provides the opportunity to instantaneously alternate between the two settings. Simultaneous surgeon control over vacuum, aspiration flow, and torsional tip motion may make removal of soft nuclear quadrants more efficient and safer.

  1. Two-speed phacoemulsification for soft cataracts using optimized parameters and procedure step toolbar with the CENTURION Vision System and Balanced Tip

    Directory of Open Access Journals (Sweden)

    Davison JA

    2015-08-01

    Full Text Available James A DavisonWolfe Eye Clinic, Marshalltown, IA, USA Purpose: To present a cause of posterior capsule aspiration and a technique using optimized parameters to prevent it from happening when operating soft cataracts.Patients and methods: A prospective list of posterior capsule aspiration cases was kept over 4,062 consecutive cases operated with the Alcon CENTURION machine and Balanced Tip. Video analysis of one case of posterior capsule aspiration was accomplished. A surgical technique was developed using empirically derived machine parameters and customized setting-selection procedure step toolbar to reduce the pace of aspiration of soft nuclear quadrants in order to prevent capsule aspiration.Results: Two cases out of 3,238 experienced posterior capsule aspiration before use of the soft quadrant technique. Video analysis showed an attractive vortex effect with capsule aspiration occurring in 1/5 of a second. A soft quadrant removal setting was empirically derived which had a slower pace and seemed more controlled with no capsule aspiration occurring in the subsequent 824 cases. The setting featured simultaneous linear control from zero to preset maximums for: aspiration flow, 20 mL/min; and vacuum, 400 mmHg, with the addition of torsional tip amplitude up to 20% after the fluidic maximums were achieved. A new setting selection procedure step toolbar was created to increase intraoperative flexibility by providing instantaneous shifting between the soft and normal settings.Conclusion: A technique incorporating a reduced pace for soft quadrant acquisition and aspiration can be accomplished through the use of a dedicated setting of integrated machine parameters. Toolbar placement of the procedure button next to the normal setting procedure button provides the opportunity to instantaneously alternate between the two settings. Simultaneous surgeon control over vacuum, aspiration flow, and torsional tip motion may make removal of soft nuclear

  2. Evaluation of the induced electric field and compliance procedure for a wireless power transfer system in an electrical vehicle

    International Nuclear Information System (INIS)

    Laakso, Ilkka; Hirata, Akimasa

    2013-01-01

    In this study, an induced electric field in a human body is evaluated for the magnetic field leaked from a wireless power transfer system for charging an electrical vehicle. The magnetic field from the wireless power transfer system is modelled computationally, and its effectiveness is confirmed by comparison with the field measured in a previous study. The induced electric field in a human standing around the vehicle is smaller than the allowable limit prescribed in international guidelines, although the magnetic field strength in the human body is locally higher than the allowable external field strength. Correlation between the external magnetic field and the induced electric field is confirmed to be reasonable at least in the standing posture, which is the case discussed in the international standard. Based on this finding, we discussed and confirmed the applicability of a three-point magnetic field measurement at heights of 0.5, 1.0, and 1.5 m for safety compliance. (paper)

  3. Optimizing the e-beam profile of a single carbon nanotube field emission device for electric propulsion systems

    Directory of Open Access Journals (Sweden)

    Juliano Fujioka Mologni

    2010-04-01

    Full Text Available Preliminary studies on field emission (FE arrays comprised of carbon nanotubes (CNT as an electron source for electric propulsion system show remarkably promising results. Design parameters for a carbon nanotube (CNT field-emission device operating on triode configuration were numerically simulated and optimized in order to enhance the e-beam focusing quality. An additional focus gate (FG was integrated to the device to control the profile of the emitted e-beam. An axisymmetric finite element model was developed to calculate the electric field distribution on the vacuum region and a modified Fowler-Nordheim (FN equation was used to evaluate the current density emission and the effective emitter area. Afterward, a FE simulation was employed in order to calculate the trajectory of the emitted electrons and define the electron-optical properties of the e-beam. The integration of the FG was fully investigated via computational intelligence techniques. The best performance device according to our simulations presents a collimated e-beam profile that suits well for field emission displays, magnetic field detection and electron microscopy. The automated computational design tool presented in this study strongly benefits the robust design of integrated electron-optical systems for vacuum field emission applications, including electrodynamic tethering and electric propulsion systems.

  4. Approval procedures for clinical trials in the field of radiation oncology; Genehmigungsverfahren klinischer Studien im Bereich der Radioonkologie

    Energy Technology Data Exchange (ETDEWEB)

    Simon, Monique; Buettner, Daniel [Deutsches Konsortium fuer Translationale Krebsforschung (DKTK), Dresden (Germany); Deutsches Krebsforschungszentrum (DKFZ), Heidelberg (Germany); Medizinische Fakultaet und Universitaetsklinikum Carl Gustav Carus, Technische Universitaet Dresden, Klinik fuer Strahlentherapie und Radioonkologie und OncoRay - Nationales Zentrum fuer Strahlenforschung in der Onkologie, Dresden (Germany); Habeck, Matthias; Habeck, Uta; Brix, Gunnar [Bundesamt fuer Strahlenschutz (BfS), Fachbereich Strahlenschutz und Gesundheit, Neuherberg (Germany); Krause, Mechthild; Baumann, Michael [Deutsches Konsortium fuer Translationale Krebsforschung (DKTK), Dresden (Germany); Deutsches Krebsforschungszentrum (DKFZ), Heidelberg (Germany); Medizinische Fakultaet und Universitaetsklinikum Carl Gustav Carus, Technische Universitaet Dresden, Klinik fuer Strahlentherapie und Radioonkologie und OncoRay - Nationales Zentrum fuer Strahlenforschung in der Onkologie, Dresden (Germany); Helmholtz-Zentrum Dresden - Rossendorf, Institut fuer Radioonkologie und OncoRay - Nationales Zentrum fuer Strahlenforschung in der Onkologie, Dresden (Germany); Willich, Normann [Universitaetsklinikum Muenster, Klinik fuer Strahlentherapie - Radioonkologie, Muenster (Germany); Wenz, Frederik [Universitaetsmedizin Mannheim, Medizinische Fakultaet Mannheim, Universitaet Heidelberg, Klinik fuer Strahlentherapie und Radioonkologie, Mannheim (Germany); Schmidberger, Heinz [Universitaetsmedizin Mainz, Klinik fuer Radioonkologie und Strahlentherapie, Mainz (Germany); Debus, Juergen [Universitaetsklinikum Heidelberg, Klinik fuer Radioonkologie und Strahlentherapie, Heidelberg (Germany); Noelling, Torsten

    2015-12-15

    Application of ionizing radiation for the purpose of medical research in Germany needs to be approved by the national authority for radiation protection (Bundesamt fuer Strahlenschutz, BfS). For studies in the field of radiation oncology, differentiation between use of radiation for ''medical care (Heilkunde)'' versus ''medical research'' frequently leads to contradictions. The aim of this article is to provide principle investigators, individuals, and institutions involved in the process, as well as institutional review or ethics committees, with the necessary information for this assessment. Information on the legal frame and the approval procedures are also provided. A workshop was co-organized by the German Society for Radiation Oncology (DEGRO), the Working Party for Radiation Oncology (ARO) of the German Cancer Society (DKG), the German Society for Medical Physics (DGMP), and the German Cancer Consortium (DKTK) in October 2013. This paper summarizes the results of the workshop and the follow-up discussions between the organizers and the BfS. Differentiating between ''Heilkunde'' which does not need to be approved by the BfS and ''medical research'' is whether the specific application of radiation (beam quality, dose, schedule, target volume, etc.) is a clinically established and recognized procedure. This must be answered by the qualified physician(s) (''fachkundiger Arzt'' according to German radiation protection law) in charge of the study and the treatments of the patients within the study, taking into consideration of the best available evidence from clinical studies, guidelines and consensus papers. Among the important parameters for assessment are indication, total dose, and fractionation. Radiation treatments applied outside clinical trials do not require approval by the BfS, even if they are applied within a randomized or nonrandomized clinical trial

  5. Overcoming limits to near-field radiative heat transfer in uniform planar media through multilayer optimization.

    Science.gov (United States)

    Jin, Weiliang; Messina, Riccardo; Rodriguez, Alejandro W

    2017-06-26

    Radiative heat transfer between uniform plates is bounded by the narrow range and limited contribution of surface waves. Using a combination of analytical calculations and numerical gradient-based optimization, we show that such a limitation can be overcome in complicated multilayer geometries, allowing the scattering and coupling rates of slab resonances to be altered over a broad range of evanescent wavevectors. We conclude that while the radiative flux between two inhomogeneous slabs can only be weakly enhanced, the flux between a dipolar particle and an inhomogeneous slab-proportional to the local density of states-can be orders of magnitude larger, albeit at the expense of increased frequency selectivity. A brief discussion of hyperbolic metamaterials shows that they provide far less enhancement than optimized inhomogeneous slabs.

  6. Optimization and evaluation of asymmetric flow field-flow fractionation of silver nanoparticles

    DEFF Research Database (Denmark)

    Löschner, Katrin; Navratilova, Jana; Legros, Samuel

    2013-01-01

    flow rate and spacer height were shown to have a significant influence on the recoveries and retention times of the nanoparticles. Focus time and focus flow rate were optimized with regard to minimum elution of AgNPs in the void volume. The developed method was successfully tested for injected masses...... especially the NP size distribution a number of parameters influencing the separation need to be optimized. This paper describes the development of a separation method for polyvinylpyrrolidone-stabilized silver nanoparticles (AgNPs) in aqueous suspension. Carrier liquid composition, membrane material, cross...... obtained by the three detection methods were explained based on the physical origin of the signal. Two different approaches for conversion of retention times of AgNPs to their corresponding sizes and size distributions were tested and compared, namely size calibration with polystyrene nanoparticles (PSNPs...

  7. Optimization of helicopter hub locations and fleet composition in the Brazilian pre-salt fields

    OpenAIRE

    Norddal, Ida Kristine

    2013-01-01

    When implementing oil and gas operations in the Santos Basin pre-salt fields, Brazilian energy corporation Petróleo Brasileiro S.A (Petrobras) faces some significant challenges. One of these is the large distance from shore: exceeding 300 km at the most, it is about three times the distance to oil fields explored in the past. This has great impact on the company's offshore helicopter operations. In its current form, helicopters transport employees directly between onshore airport bases and of...

  8. 2-D Reflectometer Modeling for Optimizing the ITER Low-field Side Reflectometer System

    International Nuclear Information System (INIS)

    Kramer, G.J.; Nazikian, R.; Valeo, E.J.; Budny, R.V.; Kessel, C.; Johnson, D.

    2005-01-01

    The response of a low-field side reflectometer system for ITER is simulated with a 2?D reflectometer code using a realistic plasma equilibrium. It is found that the reflected beam will often miss its launch point by as much as 40 cm and that a vertical array of receiving antennas is essential in order to observe a reflection on the low-field side of ITER

  9. Modular Adder Designs Using Optimal Reversible and Fault Tolerant Gates in Field-Coupled QCA Nanocomputing

    Science.gov (United States)

    Bilal, Bisma; Ahmed, Suhaib; Kakkar, Vipan

    2018-02-01

    The challenges which the CMOS technology is facing toward the end of the technology roadmap calls for an investigation of various logical and technological solutions to CMOS at the nano scale. Two such paradigms which are considered in this paper are the reversible logic and the quantum-dot cellular automata (QCA) nanotechnology. Firstly, a new 3 × 3 reversible and universal gate, RG-QCA, is proposed and implemented in QCA technology using conventional 3-input majority voter based logic. Further the gate is optimized by using explicit interaction of cells and this optimized gate is then used to design an optimized modular full adder in QCA. Another configuration of RG-QCA gate, CRG-QCA, is then proposed which is a 4 × 4 gate and includes the fault tolerant characteristics and parity preserving nature. The proposed CRG-QCA gate is then tested to design a fault tolerant full adder circuit. Extensive comparisons of gate and adder circuits are drawn with the existing literature and it is envisaged that our proposed designs perform better and are cost efficient in QCA technology.

  10. Development and Field Test of Voltage VAR Optimization in the Korean Smart Distribution Management System

    Directory of Open Access Journals (Sweden)

    Sang-Yun Yun

    2014-02-01

    Full Text Available This paper is a summary of the development and demonstration of an optimization program, voltage VAR optimization (VVO, in the Korean Smart Distribution Management System (KSDMS. KSDMS was developed to address the lack of receptivity of distributed generators (DGs, standardization and compatibility, and manual failure recovery in the existing Korean automated distribution system. Focusing on the lack of receptivity of DGs, we developed a real-time system analysis and control program. The KSDMS VVO enhances manual system operation of the existing distribution system and provides a solution with all control equipment operated at a system level. The developed VVO is an optimal power flow (OPF method that resolves violations, minimizes switching costs, and minimizes loss, and its function can vary depending on the operator’s command. The sequential mixed integer linear programming (SMILP method was adopted to find the solution of the OPF. We tested the precision of the proposed VVO on selected simulated systems and its applicability to actual systems at two substations on the Jeju Island. Running the KSDMS VVO on a regular basis improved system stability, and it also raised no issues regarding its applicability to actual systems.

  11. Population Modeling Approach to Optimize Crop Harvest Strategy. The Case of Field Tomato.

    Science.gov (United States)

    Tran, Dinh T; Hertog, Maarten L A T M; Tran, Thi L H; Quyen, Nguyen T; Van de Poel, Bram; Mata, Clara I; Nicolaï, Bart M

    2017-01-01

    In this study, the aim is to develop a population model based approach to optimize fruit harvesting strategies with regard to fruit quality and its derived economic value. This approach was applied to the case of tomato fruit harvesting under Vietnamese conditions. Fruit growth and development of tomato (cv. "Savior") was monitored in terms of fruit size and color during both the Vietnamese winter and summer growing seasons. A kinetic tomato fruit growth model was applied to quantify biological fruit-to-fruit variation in terms of their physiological maturation. This model was successfully calibrated. Finally, the model was extended to translate the fruit-to-fruit variation at harvest into the economic value of the harvested crop. It can be concluded that a model based approach to the optimization of harvest date and harvest frequency with regard to economic value of the crop as such is feasible. This approach allows growers to optimize their harvesting strategy by harvesting the crop at more uniform maturity stages meeting the stringent retail demands for homogeneous high quality product. The total farm profit would still depend on the impact a change in harvesting strategy might have on related expenditures. This model based harvest optimisation approach can be easily transferred to other fruit and vegetable crops improving homogeneity of the postharvest product streams.

  12. The choice of optimal antireflux procedure after laparoscopic cardiomyotomy: two decades of clinical experience in one center

    Science.gov (United States)

    Kiudelis, Mindaugas; Sakalys, Egidijus; Jonaitis, Laimas; Mickevicius, Antanas; Endzinas, Zilvinas

    2017-01-01

    Introduction Two types of partial wrap are commonly performed in achalasia patients after Heller myotomy: the posterior 270° fundoplication (Toupet) and the anterior 180° fundoplication (Dor). The optimal type of fundoplication (posterior vs. anterior) is still debated. Aim To compare the long-term rates of dysphagia, reflux symptoms and patient satisfaction with current postoperative condition between two fundoplication groups in achalasia treatment. Material and methods Our retrospective study included 97 consecutive patients with achalasia: 37 patients underwent laparoscopic posterior Toupet (270°) fundoplication followed by Heller myotomy (group I); 60 patients underwent laparoscopic anterior partial Dor fundoplication followed by Heller myotomy (group II). Long-term follow-up results included evaluation of dysphagia symptoms, intensity of heartburn and patient satisfaction with current condition. Results Patients in these two groups did not differ according to age, weight, height, postoperative stay or follow-up period. Laparoscopic myotomy with posterior Toupet fundoplication was effective in 89% of patients, while laparoscopic myotomy with anterior Dor was effective in 93% of patients (p > 0.05). 11% of patients after posterior Toupet fundoplication had clinically significant heartburn vs. 35% of patients after anterior Dor fundoplication (p < 0.05). Overall patient satisfaction with current condition was 88%, with no significant difference between the groups. Conclusions According to our study results, the two laparoscopic techniques were similarly effective in reducing achalasia symptoms, but postoperative clinical manifestation of heartburn is significantly more frequent after anterior Dor fundoplication (35% vs. 11%). The majority of patients (88%) were satisfied with operation outcomes. PMID:29062443

  13. Optimization of three FISH procedures for in situ detection of anaerobic ammonium oxidizing bacteria in biological wastewater treatment.

    Science.gov (United States)

    Pavlekovic, Marko; Schmid, Markus C; Schmider-Poignee, Nadja; Spring, Stefan; Pilhofer, Martin; Gaul, Tobias; Fiandaca, Mark; Löffler, Frank E; Jetten, Mike; Schleifer, K-H; Lee, Natuschka M

    2009-08-01

    Fluorescence in situ hybridization (FISH) using fluorochrome-labeled DNA oligonucleotide probes has been successfully applied for in situ detection of anaerobic ammonium oxidizing (anammox) bacteria. However, application of the standard FISH protocols to visualize anammox bacteria in biofilms from a laboratory-scale wastewater reactor produced only weak signals. Increased signal intensity was achieved either by modifying the standard FISH protocol, using peptide nucleic acid probes (PNA FISH), or applying horse radish peroxidase- (HRP-) labeled probes and subsequent catalyzed reporter deposition (CARD-FISH). A comparative analysis using anammox biofilm samples and suspended anammox biomass from different laboratory wastewater bioreactors revealed that the modified standard FISH protocol and the PNA FISH probes produced equally strong fluorescence signals on suspended biomass, but only weak signals were obtained with the biofilm samples. The probe signal intensities in the biofilm samples could be enhanced by enzymatic pre-treatment of fixed cells, and by increasing the hybridization time of the PNA FISH protocol. CARD-FISH always produced up to four-fold stronger fluorescent signals but unspecific fluorescence signals, likely caused by endogenous peroxidases as reported in several previous studies, compromised the results. Interference of the development of fluorescence intensity with endogenous peroxidases was also observed in cells of aerobic ammonium oxidizers like Nitrosomonas europea, and sulfate-reducers like Desulfobacter postgatei. Interestingly, no interference was observed with other peroxidase-positive microorganisms, suggesting that CARD-FISH is not only compromised by the mere presence of peroxidases. Pre-treatment of cells to inactivate peroxidase with HCl or autoclavation/pasteurization failed to inactive peroxidases, but H(2)O(2) significantly reduced endogenous peroxidase activity. However, for optimal inactivation, different H(2)O(2

  14. Optimized statistical parametric mapping procedure for NIRS data contaminated by motion artifacts : Neurometric analysis of body schema extension.

    Science.gov (United States)

    Suzuki, Satoshi

    2017-09-01

    This study investigated the spatial distribution of brain activity on body schema (BS) modification induced by natural body motion using two versions of a hand-tracing task. In Task 1, participants traced Japanese Hiragana characters using the right forefinger, requiring no BS expansion. In Task 2, participants performed the tracing task with a long stick, requiring BS expansion. Spatial distribution was analyzed using general linear model (GLM)-based statistical parametric mapping of near-infrared spectroscopy data contaminated with motion artifacts caused by the hand-tracing task. Three methods were utilized in series to counter the artifacts, and optimal conditions and modifications were investigated: a model-free method (Step 1), a convolution matrix method (Step 2), and a boxcar-function-based Gaussian convolution method (Step 3). The results revealed four methodological findings: (1) Deoxyhemoglobin was suitable for the GLM because both Akaike information criterion and the variance against the averaged hemodynamic response function were smaller than for other signals, (2) a high-pass filter with a cutoff frequency of .014 Hz was effective, (3) the hemodynamic response function computed from a Gaussian kernel function and its first- and second-derivative terms should be included in the GLM model, and (4) correction of non-autocorrelation and use of effective degrees of freedom were critical. Investigating z-maps computed according to these guidelines revealed that contiguous areas of BA7-BA40-BA21 in the right hemisphere became significantly activated ([Formula: see text], [Formula: see text], and [Formula: see text], respectively) during BS modification while performing the hand-tracing task.

  15. Full-zone spectral envelope function formalism for the optimization of line and point tunnel field-effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Verreck, Devin, E-mail: devin.verreck@imec.be; Groeseneken, Guido [imec, Kapeldreef 75, 3001 Leuven (Belgium); Department of Electrical Engineering, KU Leuven, 3001 Leuven (Belgium); Verhulst, Anne S.; Mocuta, Anda; Collaert, Nadine; Thean, Aaron [imec, Kapeldreef 75, 3001 Leuven (Belgium); Van de Put, Maarten; Magnus, Wim [imec, Kapeldreef 75, 3001 Leuven (Belgium); Department of Physics, Universiteit Antwerpen, 2020 Antwerpen (Belgium); Sorée, Bart [imec, Kapeldreef 75, 3001 Leuven (Belgium); Department of Physics, Universiteit Antwerpen, 2020 Antwerpen (Belgium); Department of Electrical Engineering, KU Leuven, 3001 Leuven (Belgium)

    2015-10-07

    Efficient quantum mechanical simulation of tunnel field-effect transistors (TFETs) is indispensable to allow for an optimal configuration identification. We therefore present a full-zone 15-band quantum mechanical solver based on the envelope function formalism and employing a spectral method to reduce computational complexity and handle spurious solutions. We demonstrate the versatility of the solver by simulating a 40 nm wide In{sub 0.53}Ga{sub 0.47}As lineTFET and comparing it to p-n-i-n configurations with various pocket and body thicknesses. We find that the lineTFET performance is not degraded compared to semi-classical simulations. Furthermore, we show that a suitably optimized p-n-i-n TFET can obtain similar performance to the lineTFET.

  16. Communication: Calculation of interatomic forces and optimization of molecular geometry with auxiliary-field quantum Monte Carlo

    Science.gov (United States)

    Motta, Mario; Zhang, Shiwei

    2018-05-01

    We propose an algorithm for accurate, systematic, and scalable computation of interatomic forces within the auxiliary-field quantum Monte Carlo (AFQMC) method. The algorithm relies on the Hellmann-Feynman theorem and incorporates Pulay corrections in the presence of atomic orbital basis sets. We benchmark the method for small molecules by comparing the computed forces with the derivatives of the AFQMC potential energy surface and by direct comparison with other quantum chemistry methods. We then perform geometry optimizations using the steepest descent algorithm in larger molecules. With realistic basis sets, we obtain equilibrium geometries in agreement, within statistical error bars, with experimental values. The increase in computational cost for computing forces in this approach is only a small prefactor over that of calculating the total energy. This paves the way for a general and efficient approach for geometry optimization and molecular dynamics within AFQMC.

  17. Light Water Reactor Sustainability Program: Computer-based procedure for field activities: results from three evaluations at nuclear power plants

    International Nuclear Information System (INIS)

    2014-01-01

    Nearly all activities that involve human interaction with the systems of a nuclear power plant are guided by procedures. The paper-based procedures (PBPs) currently used by industry have a demonstrated history of ensuring safety; however, improving procedure use could yield tremendous savings in increased efficiency and safety. One potential way to improve procedure-based activities is through the use of computer-based procedures (CBPs). Computer-based procedures provide the opportunity to incorporate context driven job aids, such as drawings, photos, just-in-time training, etc into CBP system. One obvious advantage of this capability is reducing the time spent tracking down the applicable documentation. Additionally, human performance tools can be integrated in the CBP system in such way that helps the worker focus on the task rather than the tools. Some tools can be completely incorporated into the CBP system, such as pre-job briefs, placekeeping, correct component verification, and peer checks. Other tools can be partly integrated in a fashion that reduces the time and labor required, such as concurrent and independent verification. Another benefit of CBPs compared to PBPs is dynamic procedure presentation. PBPs are static documents which limits the degree to which the information presented can be tailored to the task and conditions when the procedure is executed. The CBP system could be configured to display only the relevant steps based on operating mode, plant status, and the task at hand. A dynamic presentation of the procedure (also known as context-sensitive procedures) will guide the user down the path of relevant steps based on the current conditions. This feature will reduce the user's workload and inherently reduce the risk of incorrectly marking a step as not applicable and the risk of incorrectly performing a step that should be marked as not applicable. As part of the Department of Energy's (DOE) Light Water Reactors Sustainability Program

  18. Application of support vector regression for optimization of vibration flow field of high-density polyethylene melts characterized by small angle light scattering

    Science.gov (United States)

    Xian, Guangming

    2018-03-01

    In this paper, the vibration flow field parameters of polymer melts in a visual slit die are optimized by using intelligent algorithm. Experimental small angle light scattering (SALS) patterns are shown to characterize the processing process. In order to capture the scattered light, a polarizer and an analyzer are placed before and after the polymer melts. The results reported in this study are obtained using high-density polyethylene (HDPE) with rotation speed at 28 rpm. In addition, support vector regression (SVR) analytical method is introduced for optimization the parameters of vibration flow field. This work establishes the general applicability of SVR for predicting the optimal parameters of vibration flow field.

  19. In-Field Habitat Management to Optimize Pest Control of Novel Soil Communities in Agroecosystems.

    Science.gov (United States)

    Pearsons, Kirsten A; Tooker, John F

    2017-08-05

    The challenge of managing agroecosystems on a landscape scale and the novel structure of soil communities in agroecosystems both provide reason to focus on in-field management practices, including cover crop adoption, reduced tillage, and judicial pesticide use, to promote soil community diversity. Belowground and epigeal arthropods, especially exotic generalist predators, play a significant role in controlling insect pests, weeds, and pathogens in agroecosystems. However, the preventative pest management tactics that dominate field-crop production in the United States do not promote biological control. In this review, we argue that by reducing disturbance, mitigating the effects of necessary field activities, and controlling pests within an Integrated Pest Management framework, farmers can facilitate the diversity and activity of native and exotic arthropod predators.

  20. In-Field Habitat Management to Optimize Pest Control of Novel Soil Communities in Agroecosystems

    Directory of Open Access Journals (Sweden)

    Kirsten A. Pearsons

    2017-08-01

    Full Text Available The challenge of managing agroecosystems on a landscape scale and the novel structure of soil communities in agroecosystems both provide reason to focus on in-field management practices, including cover crop adoption, reduced tillage, and judicial pesticide use, to promote soil community diversity. Belowground and epigeal arthropods, especially exotic generalist predators, play a significant role in controlling insect pests, weeds, and pathogens in agroecosystems. However, the preventative pest management tactics that dominate field-crop production in the United States do not promote biological control. In this review, we argue that by reducing disturbance, mitigating the effects of necessary field activities, and controlling pests within an Integrated Pest Management framework, farmers can facilitate the diversity and activity of native and exotic arthropod predators.

  1. Analysis and Optimization for Uniformity of Magnetic Field Driving the Giant Magnetostriction

    International Nuclear Information System (INIS)

    Wang, L; Ye, H; Liu, Y T; Yao, S M

    2006-01-01

    Giant magnetostriction actuator based on material Tb0.27Dy0.73Fe2 and electromagnetic transform has characteristics of high frequency response, large output power and etc, but it has a high demand for the uniformity of magnetic field driver and magnetic intensity. Object to the problem, a multi-scale external concavity structure is proposed, by means of inducting the hollow column coil structure, building the model of coil magnetic distribution and analyzing by finite element analysis method. The analysis results show that uniformity of the model magnetic field is dependent upon magnetic intensity and scales, and the boundary condition of material. As the scale increases, magnetic uniformity is enhanced, but the magnetic intensity is decreased. Taking consideration both of magnetic field distribution and magnetic intensity, threescale structure is determined as optimum structure

  2. Task-Driven Optimization of Fluence Field and Regularization for Model-Based Iterative Reconstruction in Computed Tomography.

    Science.gov (United States)

    Gang, Grace J; Siewerdsen, Jeffrey H; Stayman, J Webster

    2017-12-01

    This paper presents a joint optimization of dynamic fluence field modulation (FFM) and regularization in quadratic penalized-likelihood reconstruction that maximizes a task-based imaging performance metric. We adopted a task-driven imaging framework for prospective designs of the imaging parameters. A maxi-min objective function was adopted to maximize the minimum detectability index ( ) throughout the image. The optimization algorithm alternates between FFM (represented by low-dimensional basis functions) and local regularization (including the regularization strength and directional penalty weights). The task-driven approach was compared with three FFM strategies commonly proposed for FBP reconstruction (as well as a task-driven TCM strategy) for a discrimination task in an abdomen phantom. The task-driven FFM assigned more fluence to less attenuating anteroposterior views and yielded approximately constant fluence behind the object. The optimal regularization was almost uniform throughout image. Furthermore, the task-driven FFM strategy redistribute fluence across detector elements in order to prescribe more fluence to the more attenuating central region of the phantom. Compared with all strategies, the task-driven FFM strategy not only improved minimum by at least 17.8%, but yielded higher over a large area inside the object. The optimal FFM was highly dependent on the amount of regularization, indicating the importance of a joint optimization. Sample reconstructions of simulated data generally support the performance estimates based on computed . The improvements in detectability show the potential of the task-driven imaging framework to improve imaging performance at a fixed dose, or, equivalently, to provide a similar level of performance at reduced dose.

  3. Nitrogen and phosphorus changes and optimal drainage time of flooded paddy field based on environmental factors

    Directory of Open Access Journals (Sweden)

    Meng-hua Xiao

    2013-04-01

    Full Text Available While many controlled irrigation and drainage techniques have been adopted in China, the environmental effects of these techniques require further investigation. This study was conducted to examine the changes of nitrogen and phosphorus of a flooded paddy water system after fertilizer application and at each growth stage so as to obtain the optimal drainage time at each growth stage. Four treatments with different water level management methods at each growth stage were conducted under the condition of ten-day continuous flooding. Results show that the ammonia nitrogen (NH+4-N concentration reached the peak value once the fertilizer was applied, and then decreased to a relatively low level seven to ten days later, and that the nitrate nitrogen (NO-3-N concentration gradually rose to its peak value, which appeared later in subsurface water than in surface water. Continuous flooding could effectively reduce the concentrations of NH+4-N, NO-3-N , and total phosphorus (TP in surface water. However, the paddy water disturbance, in the process of soil surface adsorption and nitrification, caused NH+4-N to be released and increased the concentrations of NH+4-N and NO-3-N in surface water. A multi-objective controlled drainage model based on environmental factors was established in order to obtain the optimal drainage time at each growth stage and better guide the drainage practices of farmers. The optimal times for surface drainage are the fourth, sixth, fifth, and sixth days after flooding at the tillering, jointing-booting, heading-flowering, and milking stages, respectively.

  4. One dimensional spatial resolution optimization on a hybrid low field MRI-gamma detector

    Energy Technology Data Exchange (ETDEWEB)

    Agulles-Pedrós, L., E-mail: lagullesp@unal.edu.co; Abril, A., E-mail: ajabrilf@unal.edu.co [Medical Physics Group, Physics Department, Universidad Nacional de Colombia, Bogotá (Colombia)

    2016-07-07

    Hybrid systems like Positron Emission Tomography/Magnetic Resonance Imaging (PET/MRI) and MRI/gamma camera, offer advantages combining the resolution and contrast capability of MRI with the better contrast and functional information of nuclear medicine techniques. However, the radiation detectors are expensive and need an electronic set-up, which can interfere with the MRI acquisition process or viceversa. In order to improve these drawbacks, in this work it is presented the design of a low field NMR system made up of permanent magnets compatible with a gamma radiation detector based on gel dosimetry. The design is performed using the software FEMM for estimation of the magnetic field, and GEANT4 for the physical process involved in radiation detection and effect of magnetic field. The homogeneity in magnetic field is achieved with an array of NbFeB magnets in a linear configuration with a separation between the magnets, minimizing the effect of Compton back scattering compared with a no-spacing linear configuration. The final magnetic field in the homogeneous zone is ca. 100 mT. In this hybrid proposal, although the gel detector do not have spatial resolution per se, it is possible to obtain a dose profile (1D image) as a function of the position by using a collimator array. As a result, the gamma detector system described allows a complete integrated radiation detector within the low field NMR (lfNMR) system. Finally we present the better configuration for the hybrid system considering the collimator parameters such as height, thickness and distance.

  5. Optimizing photophoresis and asymmetric force fields for grading of Brownian particles.

    Science.gov (United States)

    Neild, Adrian; Ng, Tuck Wah; Woods, Timothy

    2009-12-10

    We discuss a scheme that incorporates restricted spatial input location, orthogonal sort, and movement direction features, with particle sorting achieved by using an asymmetric potential cycled on and off, while movement is accomplished by photophoresis. Careful investigation has uncovered the odds of sorting between certain pairs of particle sizes to be solely dependent on radii in each phase of the process. This means that the most effective overall sorting can be achieved by maximizing the number of phases. This optimized approach is demonstrated using numerical simulation to permit grading of a range of nanometer-scale particle sizes.

  6. Optimization research on the concentration field of NO in selective catalytic reduction flue gas denitration system

    Science.gov (United States)

    Zheng, Qingyu; Zhang, Guoqiang; Che, Kai; Shao, Shikuan; Li, Yanfei

    2017-08-01

    Taking 660 MW generator unit denitration system as a study object, an optimization and adjustment method shall be designed to control ammonia slip, i.e. adjust ammonia injection system based on NO concentration distribution at inlet/outlet of the denitration system to make the injected ammonia distribute evenly. The results shows that, this method can effectively improve NO concentration distribution at outlet of the denitration system and decrease ammonia injection amount and ammonia slip concentration. Reduce adverse impact of SCR denitration process on the air preheater to realize safe production by guaranteeing that NO discharge shall reach the standard.

  7. Calculation and optimization of focusing electrostatic field for experiment on measurement of free neutron lifetime

    International Nuclear Information System (INIS)

    Chernyshov, V.S.; Kalebin, S.M.; Ivanov, R.N.; Pershukov, A.P.; Artamonov, V.S.

    1989-01-01

    Optimal sizes of the proton detector focusing system used in the experiment on determination of life-time of a free neutron are calculated. Angles of proton incidence on the plane of the detector window don't exceed 27 deg. Distances which protons fly along the neutron beam axis before they appear in the detector is less 4.3 cm. Analysis of proton trajectories an investigation of focusing system stability during transverse oscillations of a neutron beam permits to choose necessary width of the proton counter window by means of which all protons run to recording volume. 10 refs.; 8 figs

  8. Geometric optimization of microreactor chambers to increase the homogeneity of the velocity field

    Science.gov (United States)

    Pálovics, Péter; Ender, Ferenc; Rencz, Márta

    2018-06-01

    In this work microfluidic flow-through chambers are investigated. They are filled with magnetic nanoparticle (MNP) suspension in order to facilitate enzymatic reactions. The enzyme is immobilized on the surface of the MNPs. These reactions have been found to be flow rate dependent. To overcome this issue various chamber geometries have been examined and optimized geometries have been designed and tested experimentally. The investigation is supported with dedicated CFD simulations using the open source software OpenFOAM. The paper presents the theoretical background and the results of the simulations. The simulations have been verified with measurements and these too are presented in the paper.

  9. Optimization Problem of Thermal Field on Surface of Revolving Susceptor in Vapor-Phase Epitaxy Reactor

    Science.gov (United States)

    Zhilenkov, A. A.; Chernyi, S. G.; Nyrkov, A. P.; Sokolov, S. S.

    2017-10-01

    Nitrides of group III elements are a very suitable basis for deriving light-emitting devices with the radiating modes lengths of 200-600 nm. The use of such semiconductors allows obtaining full-color RGB light sources, increasing record density of a digital data storage device, getting high-capacity and efficient sources of white light. Electronic properties of such semi-conductors allow using them as a basis for high-power and high-frequency transistors and other electronic devices, the specifications of which are competitive with those of SiC-based devices. Only since 2000, the technology of cultivation of crystals III-N of group has come to the level of wide recognition by both abstract science, and the industry that has led to the creation of the multi-billion dollar market. And this is despite a rather low level of development of the production technology of devices on the basis of III-N of materials. The progress that has happened in the last decade requires the solution of the main problem, constraining further development of this technology today - ensuring cultivation of III-N structures of necessary quality. For this purpose, it is necessary to solve problems of the analysis and optimization of processes in installations of epitaxial growth, and, as a result, optimization of its constructions.

  10. Study and optimal correction of a systematic skew quadrupole field in the Tevatron

    International Nuclear Information System (INIS)

    Snopok, Pavel; Johnstone, Carol; Berz, Martin; Ovsyannikov, Dmitry A.; Ovsyannikov, Alexander D.

    2006-01-01

    Increasing demands for luminosity in existing and future colliders have made lattice design and error tolerance and correction critical to achieving performance goals. The current state of the Tevatron collider is an example, with a strong skew quadrupole error present in the operational lattice. This work studies the high-order performance of the Tevatron and the strong nonlinear behavior introduced when a significant skew quadrupole error is combined with conventional sextupole correction, a behavior still clearly evident after optimal tuning of available skew quadrupole circuits. An optimization study is performed using different skew quadrupole families, and, importantly, local and global correction of the linear skew terms in maps generated by the code COSY INFINITY [M. Berz, COSY INFINITY version 8.1 user's guide and reference manual, Department of Physics and Astronomy MSUHEP-20704, Michigan State University (2002). URL http://cosy.pa.msu.edu/cosymanu/index.html]. Two correction schemes with one family locally correcting each arc and eight independent correctors in the straight sections for global correction are proposed and shown to dramatically improve linearity and performance of the baseline Tevatron lattice

  11. Improvements in emittance wake field optimization for the SLAC Linear Collider

    CERN Document Server

    Decker, Franz Josef

    2003-01-01

    The transverse emittances in the SLAC Linear Collider can be severely diluted by collective wakefield effects and dispersion. For the 1997/98 SLC/SLD run important changes were implemented in the way the emittance is optimized. Early in the linac, where the energy spread is large due to BNS damping, the emittance growth is dominated by dispersion. In this regime emittance tuning bumps may introduce additional wakefield tails and their use is now avoided. At the end of the linac the energy spread is minimal and the emittance measurement is most sensitive to wakefield emittance dilution. In previous years, the emittances were tuned on wire scanners located near but not at the end of the linac (after about 90% of its length). Simulations show that emittance growth of up to 100% can occur in the remaining 10%. In this run wire scanners at the entrance of the Final Focus, the last place where the emittances can be measured, were used for the optimization. Screens at the end of the linac allow additional real time ...

  12. Application of PK/PD Modeling in Veterinary Field: Dose Optimization and Drug Resistance Prediction

    Directory of Open Access Journals (Sweden)

    Ijaz Ahmad

    2016-01-01

    Full Text Available Among veterinary drugs, antibiotics are frequently used. The true mean of antibiotic treatment is to administer dose of drug that will have enough high possibility of attaining the preferred curative effect, with adequately low chance of concentration associated toxicity. Rising of antibacterial resistance and lack of novel antibiotic is a global crisis; therefore there is an urgent need to overcome this problem. Inappropriate antibiotic selection, group treatment, and suboptimal dosing are mostly responsible for the mentioned problem. One approach to minimizing the antibacterial resistance is to optimize the dosage regimen. PK/PD model is important realm to be used for that purpose from several years. PK/PD model describes the relationship between drug potency, microorganism exposed to drug, and the effect observed. Proper use of the most modern PK/PD modeling approaches in veterinary medicine can optimize the dosage for patient, which in turn reduce toxicity and reduce the emergence of resistance. The aim of this review is to look at the existing state and application of PK/PD in veterinary medicine based on in vitro, in vivo, healthy, and disease model.

  13. SAGD gas lift completions and optimization : a field case study at Surmont

    Energy Technology Data Exchange (ETDEWEB)

    Handfield, T.C.; Nations, T.; Noonan, S.G. [ConocoPhillips Co., Houston, TX (United States)

    2008-10-15

    Gas lift completions for steam assisted gravity drainage (SAGD) producers are unique. Because of the extreme temperatures of the downhole environment, conventional gas lift valves and mandrels with a packer completion cannot be used. Most gas lifts enter the production stream downhole through open-ended tubing or nozzles, which if not properly sized could result in operational issues, such as fluid/gas slugging and pressure instabilities which negatively effect the overall lift efficiency. ConocoPhillips performed a study in 2006 to design a gas lift system for the Surmont SAGD development that would allow better control of lift gas into the production string. The wells completed with gas lift were placed on production in 2007. This paper discussed the data collection effort and analysis completed to determine the efficiency of the two types of gas lift nozzles used in the completions. It also presented the methodology for optimization of SAGD gas lift systems and recommendations for future improvement. Background information on the Surmont oil sands project, located southeast of Fort McMurray in the Athabasca oil sands was included along with a historical perspective of the SAGD Surmont gas lift experience followed by a discussion of the Surmont initial gas lift design. Last, the paper discussed the Surmont gas lift start-up and optimization. It was concluded that installation of backcheck valves in coil tubing used for gas lift may mitigate plugging issues on initial start-up and following periods of shut-down. 5 refs., 10 figs.

  14. Optimization of synthesis and quality control procedures for the preparation of 18F and 123I labelled peptides for nuclear medicine

    International Nuclear Information System (INIS)

    2002-09-01

    The general scope of this CRP focused on the optimization of syntheses, quality control, in vitro and in vivo evaluation of 18 F and 123 I radiopharmaceuticals based on peptides with known or anticipated clinical potential. Selective labelling procedures using prosthetic groups were applied to both fluorine and iodine. Studies included investigation on the fate of the label, stability in vivo, biodistribution and pharmacokinetic studies in rodents and in cell culture. With respect to 123 I, the work aimed at developing a simplified labelling kit using solid state systems. The first Research Co-ordination Meeting (RCM) that was held in August 1997 took up and decided on the criteria for selecting the peptides and agreed upon a set of recommended laboratory protocols for the CRP participants to follow and further optimize. Eight scientists from reputed laboratories from Argentina, Brazil, China, Germany, Greece, the Islamic Republic of Iran, Saudi Arabia and the United States of America participated in the CRP. Three RCMs were held where the participants presented their scientific results: August 1997 in Sao Paulo, Brazil, April 1999 in Athens, Greece, and November 2000 in Shanghai, People's Republic of China. Reports describing the research work of all participants are included herein. Each of the report has been indexed separately

  15. Gas chromatographic-mass spectrometric analysis of urinary volatile organic metabolites: Optimization of the HS-SPME procedure and sample storage conditions.

    Science.gov (United States)

    Živković Semren, Tanja; Brčić Karačonji, Irena; Safner, Toni; Brajenović, Nataša; Tariba Lovaković, Blanka; Pizent, Alica

    2018-01-01

    Non-targeted metabolomics research of human volatile urinary metabolome can be used to identify potential biomarkers associated with the changes in metabolism related to various health disorders. To ensure reliable analysis of urinary volatile organic metabolites (VOMs) by gas chromatography-mass spectrometry (GC-MS), parameters affecting the headspace-solid phase microextraction (HS-SPME) procedure have been evaluated and optimized. The influence of incubation and extraction temperatures and times, coating fibre material and salt addition on SPME efficiency was investigated by multivariate optimization methods using reduced factorial and Doehlert matrix designs. The results showed optimum values for temperature to be 60°C, extraction time 50min, and incubation time 35min. The proposed conditions were applied to investigate urine samples' stability regarding different storage conditions and freeze-thaw processes. The sum of peak areas of urine samples stored at 4°C, -20°C, and -80°C up to six months showed a time dependent decrease over time although storage at -80°C resulted in a slight non-significant reduction comparing to the fresh sample. However, due to the volatile nature of the analysed compounds, more than two cycles of freezing/thawing of the sample stored for six months at -80°C should be avoided whenever possible. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Self-organization, free energy minimization, and optimal grip on a field of affordances

    NARCIS (Netherlands)

    Bruineberg, Jelle; Rietveld, Erik

    2014-01-01

    In this paper, we set out to develop a theoretical and conceptual framework for the new field of Radical Embodied Cognitive Neuroscience. This framework should be able to integrate insights from several relevant disciplines: theory on embodied cognition, ecological psychology, phenomenology,

  17. Optimization of field emission properties of carbon nanotubes by Taguchi method

    International Nuclear Information System (INIS)

    Ting, J.-H.; Chang, C.-C.; Chen, S.-L.; Lu, D.-S.; Kung, C.-Y.; Huang, F.-Y.

    2006-01-01

    It is the purpose of this study to evaluate the field emission property of carbon nanotubes (CNTs) prepared by microwave plasma-enhanced chemical vapor deposition (MPCVD) method. Nickel layer of 5 nm in thickness on 20-nm thickness titanium nitride film was transformed into discrete islands after hydrogen plasma pretreatment. CNTs were then grown up on Ni-coated areas by MPCVD. Through the practice of Taguchi method, superior CNT films with very low emission onset electric field, about 0.7 V/μm (at J = 10 μA/cm 2 ), are attained without post-deposition treatment. It is found that microwave power has the most important influence on the field emission characteristics of CNT films. The increase of methane flow ratio will downgrade the degree of graphitization of CNT and thus its field emission characteristics. Scanning electron microscope and transmission electron microscopy (TEM) observation and energy dispersive X-ray spectrometer analysis reveal that CNT growth by MPCVD is based on tip-growth mechanism. TEM micrographs validate the hollow, bamboo-like structure of the multi-walled CNTs

  18. Environmental optimization and shielding for NMR experiments and imaging in the earth's magnetic field.

    Science.gov (United States)

    Favre, B; Bonche, J P; Meheir, H; Peyrin, J O

    1990-02-01

    For many years, a number of laboratories have been working on the applications of very low field NMR. In 1985, our laboratory presented the first NMR images using the earth's magnetic field. However, the use of this technique was limited by the weakness of the signal and the disturbing effects of the environment on the signal-to-noise ratio and on the homogeneity of the static magnetic field. Therefore experiments has to be performed in places with low environmental disturbances, such as open country or large parks. In 1986, we installed a new station in Lyon, in the town's hostile environment. Good NMR signals can now be obtained (with a signal-to-noise ratio better than 200 and a time constant T2 better than 3s for 200-mnl water samples and at a temperature of about 40 degrees C). We report the terrace roof of our faculty building. Gradient coils were used to correct the local inhomogeneities of the earth's magnetic field. We show FIDs and MR images of water-filled tubes made with or without these improvements.

  19. General planar transverse domain walls realized by optimized transverse magnetic field pulses in magnetic biaxial nanowires

    Science.gov (United States)

    Li, Mei; Wang, Jianbo; Lu, Jie

    2017-02-01

    The statics and field-driven dynamics of transverse domain walls (TDWs) in magnetic nanowires (NWs) have attracted continuous interests because of their theoretical significance and application potential in future magnetic logic and memory devices. Recent results demonstrate that uniform transverse magnetic fields (TMFs) can greatly enhance the wall velocity, meantime leave a twisting in the TDW azimuthal distribution. For application in high-density NW devices, it is preferable to erase the twisting so as to minimize magnetization frustrations. Here we report the realization of a completely planar TDW with arbitrary tilting attitude in a magnetic biaxial NW under a TMF pulse with fixed strength and well-designed orientation profile. We smooth any twisting in the TDW azimuthal plane thus completely decouple the polar and azimuthal degrees of freedom. The analytical differential equation describing the polar angle distribution is derived and the resulting solution is not the Walker-ansatz form. With this TMF pulse comoving, the field-driven dynamics of the planar TDW is investigated with the help of the asymptotic expansion method. It turns out the comoving TMF pulse increases the wall velocity under the same axial driving field. These results will help to design a series of modern magnetic devices based on planar TDWs.

  20. Simulated near-field mapping of ripple pattern supported metal nanoparticles arrays for SERS optimization

    Science.gov (United States)

    Arya, Mahima; Bhatnagar, Mukul; Ranjan, Mukesh; Mukherjee, Subroto; Nath, Rabinder; Mitra, Anirban

    2017-11-01

    An analytical model has been developed using a modified Yamaguchi model along with the wavelength dependent plasmon line-width correction. The model has been used to calculate the near-field response of random nanoparticles on the plane surface, elongated and spherical silver nanoparticle arrays supported on ion beam produced ripple patterned templates. The calculated near-field mapping for elongated nanoparticles arrays on the ripple patterned surface shows maximum number of hot-spots with a higher near-field enhancement (NFE) as compared to the spherical nanoparticle arrays and randomly distributed nanoparticles on the plane surface. The results from the simulations show a similar trend for the NFE when compared to the far field reflection spectra. The nature of the wavelength dependent NFE is also found to be in agreement with the observed experimental results from surface enhanced Raman spectroscopy (SERS). The calculated and the measured optical response unambiguously reveal the importance of interparticle gap and ordering, where a high intensity Raman signal is obtained for ordered elongated nanoparticles arrays case as against non-ordered and the aligned configuration of spherical nanoparticles on the rippled surface.

  1. A Platform to Optimize the Field Emission Properties of Carbon Nanotube Based Fibers (Postprint)

    Science.gov (United States)

    2016-08-25

    characterization of key metrics , such as effective field enhancement factor and emission area. It is imperative to address issues relating to whether...important are the effects of Coulomb repulsion between adjacent emitting CNTs on the FE characteristics? When do space-charge effects become important and

  2. Evaluation of the induced electric field and compliance procedure for a wireless power transfer system in an electrical vehicle.

    Science.gov (United States)

    Laakso, Ilkka; Hirata, Akimasa

    2013-11-07

    In this study, an induced electric field in a human body is evaluated for the magnetic field leaked from a wireless power transfer system for charging an electrical vehicle. The magnetic field from the wireless power transfer system is modelled computationally, and its effectiveness is confirmed by comparison with the field measured in a previous study. The induced electric field in a human standing around the vehicle is smaller than the allowable limit prescribed in international guidelines, although the magnetic field strength in the human body is locally higher than the allowable external field strength. Correlation between the external magnetic field and the induced electric field is confirmed to be reasonable at least in the standing posture, which is the case discussed in the international standard. Based on this finding, we discussed and confirmed the applicability of a three-point magnetic field measurement at heights of 0.5, 1.0, and 1.5 m for safety compliance.

  3. Statistically optimized near field acoustic holography using an array of pressure-velocity probes

    DEFF Research Database (Denmark)

    Jacobsen, Finn; Jaud, Virginie

    2007-01-01

    of a measurement aperture that extends well beyond the source can be relaxed. Both NAH and SONAH are based on the assumption that all sources are on one side of the measurement plane whereas the other side is source free. An extension of the SONAH procedure based on measurement with a double layer array...... of pressure microphones has been suggested. The double layer technique makes it possible to distinguish between sources on the two sides of the array and thus suppress the influence of extraneous noise coming from the “wrong” side. It has also recently been demonstrated that there are significant advantages...... in NAH based on an array of acoustic particle velocity transducers (in a single layer) compared with NAH based on an array of pressure microphones. This investigation combines the two ideas and examines SONAH based on an array of pressure-velocity intensity probes through computer simulations as well...

  4. OPTIMIZATION OF PATCHOULI OIL (POGOSTEMON CABLIN, BENTH WITH STEAM DISTILLATION ASSISTED BY PULSED ELECTRIC FIELD VIA RESPONSE SURFACE METHODOLOGY

    Directory of Open Access Journals (Sweden)

    SUKARDI

    2017-08-01

    Full Text Available The study was aimed to determine the role of pulsed electric field (PEF treatment before hydro-distillation of the patchouli oil. Response Surface Methodology (RSM was employed to optimize PEF treatment (voltages, frequencies and times of distillation of patchouli oil from dried patchouli crops. The experimental design and analysis the result to obtain the optimal processing parameters was a Box-Behnken Design (BBD. Three variables were examined in this study: voltages (1,000-2,000 volt; frequencies (1,000-2,000 Hz; and distillation time (4-8 hours. The results showed that the voltage greatly affects the volume of patchouli oil obtained and optimum condition of PEF was voltages of 2,000 volts, frequencies of 1,874 Hz, and 8 hours distillation. The patchouli oil obtained is 8.037 ml of 300 g of dry material (±2.7%. The verification of the model shows that 96.6% (7.76±0.15 ml can adequately for reflecting the expected optimization.

  5. Optimation of patient positioning and irradiation field documentation when irradiating in oto-rhino-laryngological area

    International Nuclear Information System (INIS)

    Proske, H.

    1992-01-01

    The large mobility of head and neck requires, when irradiating in this area, positioning and fastening aids, which go beyond simple head bolsters or head moulds. This paper presented describes a positioning system developed by us for irradiating the neck-nose-throat area, which, due to its construction, consists of a non-slipping positioning ground plate and an individually adjustable masking system, which is physiological safe, can be proceeded quickly and exactly, is relatively inexpensive, and is accepted by patients without objections, furthermore since skin markings by drawing field limits onto the face mask are no longer necessary. Various technical aids allow the placement of satellites to spare those body parts which are not irradiated and to installed compensators for the direction of radiation. An integrated cartridge mount enables in a simple way easy production of field control documentation photos. (orig.) [de

  6. Application of the random field theory in PET imaging - injection dose optimization

    Czech Academy of Sciences Publication Activity Database

    Dvořák, Jiří; Boldyš, Jiří; Skopalová, M.; Bělohlávek, O.

    2013-01-01

    Roč. 49, č. 2 (2013), s. 280-300 ISSN 0023-5954 R&D Projects: GA MŠk 1M0572 Institutional support: RVO:67985556 Keywords : random field theory * Euler characteristic * PET imaging * PET image quality Subject RIV: BD - Theory of Information Impact factor: 0.563, year: 2013 http://library.utia.cas.cz/separaty/2013/ZOI/boldys-0397176.pdf

  7. Performance optimization of a cusp-field ion source and high-perveance extractor

    International Nuclear Information System (INIS)

    Meyer, E.A.; Amstrong, D.D.; Schneider, D.

    1981-01-01

    The injector for the Fusion Materials Irradiation Test (FMIT) Facility must deliver a 110-mA dc beam of deuterons or H 2 + ions to the radio-frequency quadrupole (RFQ) accelerator at 75-keV energy. Operational parameters of a hydrogen-fed cusp-field ion source and a high-perveance extractor have been evaluated on a test stand and on the recently completed first stage of the prototype injector

  8. High resolution modelling of wind fields for optimization of empirical storm flood predictions

    Science.gov (United States)

    Brecht, B.; Frank, H.

    2014-05-01

    High resolution wind fields are necessary to predict the occurrence of storm flood events and their magnitude. Deutscher Wetterdienst (DWD) created a catalogue of detailed wind fields of 39 historical storms at the German North Sea coast from the years 1962 to 2011. The catalogue is used by the Niedersächsisches Landesamt für Wasser-, Küsten- und Naturschutz (NLWKN) coastal research center to improve their flood alert service. The computation of wind fields and other meteorological parameters is based on the model chain of the DWD going from the global model GME via the limited-area model COSMO with 7 km mesh size down to a COSMO model with 2.2 km. To obtain an improved analysis COSMO runs are nudged against observations for the historical storms. The global model GME is initialised from the ERA reanalysis data of the European Centre for Medium-Range Weather Forecasts (ECMWF). As expected, we got better congruency with observations of the model for the nudging runs than the normal forecast runs for most storms. We also found during the verification process that different land use data sets could influence the results considerably.

  9. Optimality Conditions in Vector Optimization

    CERN Document Server

    Jiménez, Manuel Arana; Lizana, Antonio Rufián

    2011-01-01

    Vector optimization is continuously needed in several science fields, particularly in economy, business, engineering, physics and mathematics. The evolution of these fields depends, in part, on the improvements in vector optimization in mathematical programming. The aim of this Ebook is to present the latest developments in vector optimization. The contributions have been written by some of the most eminent researchers in this field of mathematical programming. The Ebook is considered essential for researchers and students in this field.

  10. Optimization of L-shaped tunneling field-effect transistor for ambipolar current suppression and Analog/RF performance enhancement

    Science.gov (United States)

    Li, Cong; Zhao, Xiaolong; Zhuang, Yiqi; Yan, Zhirui; Guo, Jiaming; Han, Ru

    2018-03-01

    L-shaped tunneling field-effect transistor (LTFET) has larger tunnel area than planar TFET, which leads to enhanced on-current ION . However, LTFET suffers from severe ambipolar behavior, which needs to be further optimized for low power and high-frequency applications. In this paper, both hetero-gate-dielectric (HGD) and lightly doped drain (LDD) structures are introduced into LTFET for suppression of ambipolarity and improvement of analog/RF performance of LTFET. Current-voltage characteristics, the variation of energy band diagrams, distribution of band-to-band tunneling (BTBT) generation and distribution of electric field are analyzed for our proposed HGD-LDD-LTFET. In addition, the effect of LDD on the ambipolar behavior of LTFET is investigated, the length and doping concentration of LDD is also optimized for better suppression of ambipolar current. Finally, analog/RF performance of HGD-LDD-LTFET are studied in terms of gate-source capacitance, gate-drain capacitance, cut-off frequency, and gain bandwidth production. TCAD simulation results show that HGD-LDD-LTFET not only drastically suppresses ambipolar current but also improves analog/RF performance compared with conventional LTFET.

  11. Depositional features of the Middle Jurassic formation of Field N and their influence on optimal drilling schedule

    International Nuclear Information System (INIS)

    Mishina, D; Rukavishnikov, V; Belozerov, B; Bochkov, A

    2015-01-01

    The Middle Jurassic formation of Field N represented by 4 hydrodynamically connected layers (J5-6, J4, J3 and J2) contains 42% of the field STOIIP. The J2-6 formation is characterized as a gas-oil-condensate massive lithologically and tectonically screened accumulation with a gas cap (J2, J3 layers) and bottom water (J5-6 layer). Oil is predominantly in the J3 and J4 layers. There is a high risk of early gas coning from gas-bearing layers to oil producing wells determined on the basis of production test results, which can significantly decrease the life of the well. To select a more optimal drilling schedule, it is necessary to take the risk of early gas coning into account and determine distinctive features within the gas- saturated zone that can reduce it. The presence of a thick shale barrier between the J2 and J3 layers with thicknesses varying from 0 to 30 m is recognized as the beginning of a transgression cycle, and if the gas cap is only in the J2 layer, this barrier with the thickness of more than 5 m can extensively prevent early gas coning into oil producing wells. The integration of geological information represented by the probability map constructed and petrophysical information represented by the kh map provide the more precise determination of an optimal drilling schedule

  12. Hybrid PET/MRI insert: B0 field optimization by applying active and passive shimming on PET detector level

    Energy Technology Data Exchange (ETDEWEB)

    Wehner, Jakob [Department of Physics of Molecular Imaging Systems, Institute for Experimental Molecular Imaging, RWTH Aachen University, Aachen (Germany); Weissler, Bjoern [Philips Research Europe, Aachen (Germany); Schulz, Volkmar [Department of Physics of Molecular Imaging Systems, Institute for Experimental Molecular Imaging, RWTH Aachen University, Aachen (Germany); Philips Research Europe, Aachen (Germany)

    2014-07-29

    Combining PET and MRI into a hybrid device is challenging since both systems might influence each other. A typical interference problem of such a combined device is the distortion of the MRI’s B{sub 0} field distribution due to the material brought inside the MRI’s FOV which is in particular challenging for small-bore PET-systems. High field homogeneity is needed for a good MRI acquisition in general as well as in certain applications. Typically, active shimming using dedicated coils is applied to improve the field homogeneity. However, these techniques are limited especially for localized distortion profiles with higher-order characteristics caused by PET/MRI inserts. As a consequence, we are exploring the potential application of shimming on PET detector level (for the Hyperion-II{sup D} PET/MRI insert), meaning that the distortion profile caused by PET modules is compensated using additional magnetic materials (passive shimming) and DC coils (active shimming). To explore the technique, B{sub 0} field measurements have been performed using a whole-body phantom in combination with the MRI body coil. An FFE sequence was used to measure distortion maps of DC loops and small magnetic objects (capacitors, ferrites). These distortion maps served as input for a software framework which has been written to perform the field optimization. The implementation was verified by measurements and fits were performed to extract characteristic parameters of the tested objects. Finally, the implemented software framework was used to homogenize a measured distortion map produced by a single PET module by superimposing distortion corrections from additional simulated materials. The resulting superimposed distortion map showed a significantly improved B{sub 0} field map quality (reduced spectral width and improved homogeneity). The simulated susceptibility distribution will be applied on PET module level and tested in experiments. Results and details about this study will be

  13. Optimal distribution of temperature points in μSR measurement of local field

    International Nuclear Information System (INIS)

    Pełka, R.; Zieliński, P.M.; Konieczny, P.; Wasiutyński, T.

    2013-01-01

    Three possible distributions of temperature points in the μSR measurement of local field (order parameter) are discussed. The least square method is applied to estimate the scale of the deviations of the fitted parameters from the true values. It indicates that the distribution corresponding to a uniform section of the order parameter values (uniform-in-signal) incurs the smallest errors. The distribution constructed on the basis of the zeros of the Chebyshev polynomials yields comparable uncertainties, while the uniform-in-temperature distribution turns out to be least effective incurring considerably larger errors. These findings can be useful while planning an order parameter measurement in the μSR experiment

  14. Optimization of a therapeutic electromagnetic field (EMF) to retard breast cancer tumor growth and vascularity

    OpenAIRE

    Cameron, Ivan L; Markov, Marko S; Hardman, W Elaine

    2014-01-01

    Background This study provided additional data on the effects of a therapeutic electromagnetic field (EMF) device on growth and vascularization of murine 16/C mammary adenocarcinoma cells implanted in C3H/HeJ mice. Methods The therapeutic EMF device generated a defined 120 Hz semi sine wave pulse signal of variable intensity. Murine 16/C mammary adenocarcinoma tumor fragments were implanted subcutaneously between the scapulae of syngeneic C3H mice. Once the tumor grew to 100 mm3, daily EMF tr...

  15. Technical procedures for water resources: Volume 4, Deaf Smith County site, Texas: Environmental Field Program: Final draft

    International Nuclear Information System (INIS)

    1987-08-01

    This volume contains Technical Procedures pursuant to the water Resources Site Study Plan: including Collection, Preservation, and Shipment of Ground-Water Samples; Inventory Current Water Use and Estimating Projected Water Use; Estimation of Precipitation Depth, Duration, Frequence; Estimation of Probable Maximum Precipitation; Calculation of Floodplains

  16. Technical procedures for water resources, Deaf Smith County site, Texas: Volume 1: Environmental Field Program: Final draft

    International Nuclear Information System (INIS)

    1987-08-01

    This volume contains Technical Procedures pursuant to the Water Resources Site Study Plan including, determination of basin topographic characteristics, determination of channel and playa lake characteristics, operation of a stream gaging station, operation of a playa lake stage gaging system, and processing of data from a playa lake stage gaging system

  17. Chemometrics Optimized Extraction Procedures, Phytosynergistic Blending and in vitro Screening of Natural Enzyme Inhibitors Amongst Leaves of Tulsi, Banyan and Jamun.

    Science.gov (United States)

    De, Baishakhi; Bhandari, Koushik; Singla, Rajeev K; Katakam, Prakash; Samanta, Tanmoy; Kushwaha, Dilip Kumar; Gundamaraju, Rohit; Mitra, Analava

    2015-10-01

    Tulsi, Banyan, and Jamun are popular Indian medicinal plants with notable hypoglycemic potentials. Now the work reports chemo-profiling of the three species with in-vitro screening approach for natural enzyme inhibitors (NEIs) against enzymes pathogenic for type 2 diabetes. Further along with the chemometrics optimized extraction process technology, phyto-synergistic studies of the composite polyherbal blends have also been reported. Chemometrically optimized extraction procedures, ratios of polyherbal composites to achieve phyto-synergistic actions, and in-vitro screening of NEIs amongst leaves of Tulsi, Banyan, and Jamun. The extraction process parameters of the leaves of three plant species (Ficus benghalensis, Syzigium cumini and Ocimum sanctum) were optimized by rotatable central composite design of chemometrics so as to get maximal yield of bio-actives. Phyto-blends of three species were prepared so as to achieve synergistic antidiabetic and antioxidant potentials and the ratios were optimized by chemometrics. Next, for in vitro screening of natural enzyme inhibitors the individual leaf extracts as well as composite blends were subjected to assay procedures to see their inhibitory potentials against the enzymes pathogenic in type 2 diabetes. The antioxidant potentials were also estimated by DPPH radical scavenging, ABTS, FRAP and Dot Blot assay. Considering response surface methodology studies and from the solutions obtained using desirability function, it was found that hydro-ethanolic or methanolic solvent ratio of 52.46 ± 1.6 and at a temperature of 20.17 ± 0.6 gave an optimum yield of polyphenols with minimal chlorophyll leaching. The species also showed the presence of glycosides, alkaloids, and saponins. Composites in the ratios of 1:1:1 and 1:1:2 gave synergistic effects in terms of polyphenol yield and anti-oxidant potentials. All composites (1:1:1, 1:2:1, 2:1:1, 1:1:2) showed synergistic anti-oxidant actions. Inhibitory activities against the

  18. Integrating biology, field logistics, and simulations to optimize parameter estimation for imperiled species

    Science.gov (United States)

    Lanier, Wendy E.; Bailey, Larissa L.; Muths, Erin L.

    2016-01-01

    Conservation of imperiled species often requires knowledge of vital rates and population dynamics. However, these can be difficult to estimate for rare species and small populations. This problem is further exacerbated when individuals are not available for detection during some surveys due to limited access, delaying surveys and creating mismatches between the breeding behavior and survey timing. Here we use simulations to explore the impacts of this issue using four hypothetical boreal toad (Anaxyrus boreas boreas) populations, representing combinations of logistical access (accessible, inaccessible) and breeding behavior (synchronous, asynchronous). We examine the bias and precision of survival and breeding probability estimates generated by survey designs that differ in effort and timing for these populations. Our findings indicate that the logistical access of a site and mismatch between the breeding behavior and survey design can greatly limit the ability to yield accurate and precise estimates of survival and breeding probabilities. Simulations similar to what we have performed can help researchers determine an optimal survey design(s) for their system before initiating sampling efforts.

  19. Selection of candidate wells and optimization of conformance treatment design in the Barrancas Field using a 3D conformance simulator

    Energy Technology Data Exchange (ETDEWEB)

    Crosta, Dante; Elitseche, Luis [Repsol YPF (Argentina); Gutierrez, Mauricio; Ansah, Joe; Everett, Don [Halliburton Argentina S.A., Buenos Aires (Argentina)

    2004-07-01

    Minimizing the amount of unwanted water production is an important goal at the Barrancas field. This paper describes a selection process for candidate injection wells that is part of a pilot conformance project aimed at improving vertical injection profiles, reducing water cut in producing wells, and improving ultimate oil recovery from this field. The well selection process is based on a review of limited reservoir information available for this field to determine inter-well communications. The methodology focuses on the best use of available information, such as production and injection history, well intervention files, open hole logs and injectivity surveys. After the candidate wells were selected and potential water injection channels were identified, conformance treatment design and future performance of well