WorldWideScience

Sample records for complex surfaces verification

  1. Uncertainty analysis of point-by-point sampling complex surfaces using touch probe CMMs DOE for complex surfaces verification with CMM

    DEFF Research Database (Denmark)

    Barini, Emanuele Modesto; Tosello, Guido; De Chiffre, Leonardo

    2010-01-01

    The paper describes a study concerning point-by-point sampling of complex surfaces using tactile CMMs. A four factor, two level completely randomized factorial experiment was carried out, involving measurements on a complex surface configuration item comprising a sphere, a cylinder and a cone, co...

  2. Land surface Verification Toolkit (LVT)

    Science.gov (United States)

    Kumar, Sujay V.

    2017-01-01

    LVT is a framework developed to provide an automated, consolidated environment for systematic land surface model evaluation Includes support for a range of in-situ, remote-sensing and other model and reanalysis products. Supports the analysis of outputs from various LIS subsystems, including LIS-DA, LIS-OPT, LIS-UE. Note: The Land Information System Verification Toolkit (LVT) is a NASA software tool designed to enable the evaluation, analysis and comparison of outputs generated by the Land Information System (LIS). The LVT software is released under the terms and conditions of the NASA Open Source Agreement (NOSA) Version 1.1 or later. Land Information System Verification Toolkit (LVT) NOSA.

  3. Verification and Examination Management of Complex Systems

    Directory of Open Access Journals (Sweden)

    Stian Ruud

    2014-10-01

    Full Text Available As ship systems become more complex, with an increasing number of safety-critical functions, many interconnected subsystems, tight integration to other systems, and a large amount of potential failure modes, several industry parties have identified the need for improved methods for managing the verification and examination efforts of such complex systems. Such needs are even more prominent now that the marine and offshore industries are targeting more activities and operations in the Arctic environment. In this paper, a set of requirements and a method for verification and examination management are proposed for allocating examination efforts to selected subsystems. The method is based on a definition of a verification risk function for a given system topology and given requirements. The marginal verification risks for the subsystems may then be evaluated, so that examination efforts for the subsystem can be allocated. Two cases of requirements and systems are used to demonstrate the proposed method. The method establishes a systematic relationship between the verification loss, the logic system topology, verification method performance, examination stop criterion, the required examination effort, and a proposed sequence of examinations to reach the examination stop criterion.

  4. Verification of aspheric contact lens back surfaces.

    Science.gov (United States)

    Dietze, Holger H; Cox, Michael J; Douthwaite, William A

    2003-08-01

    To suggest a tolerance level for the degree of asphericity of aspheric rigid gas-permeable contact lenses and to find a simple method for its verification. Using existing tolerances for the vertex radius, tolerance limits for eccentricity and p values and were calculated. A keratometer-based method and a method based on sag measurements were used to measure the vertex radius and eccentricity of eight concave progressively aspheric surfaces and six concave ellipsoidal surfaces. The results were compared with a gold standard measurement made using a high-precision mechanical instrument (Form Talysurf). The suggested tolerance for eccentricity and p value and is +/-0.05. The keratometer method was very accurate and precise at measuring the vertex radius (mean deviation +/- SD from Talysurf results, -0.002 +/- 0.008 mm). The keratometer was more precise than and similar in accuracy to the sag method for measurement of asphericity (mean deviation of keratometer method results from Talysurf results, 0.017 +/- 0.018; mean deviation of sag method results from Talysurf results using five semichords, -0.016 +/- 0.032). Neither method was precise enough to verify the asphericity within the suggested tolerance. The keratometer can be efficiently used to verify the back vertex radius within its International Organization for Standardization tolerance and the back surface asphericity within an eccentricity/p value tolerance of +/-0.1. The method is poor for progressive aspheres with large edge blending zones. Deriving the eccentricity from sag measurements is a potential alternative if the mathematical description of the surface is known. The limiting factor of this method is the accuracy and precision of individual sag measurements.

  5. Fluence complexity for IMRT field and simplification of IMRT verification

    International Nuclear Information System (INIS)

    Hanushova, Tereza; Vondarchek, Vladimir

    2013-01-01

    Intensity Modulated Radiation Therapy (IMRT) requires dosimetric verification of each patient’s plan, which is time consuming. This work deals with the idea of minimizing the number of fields for control, or even replacing plan verification by machine quality assurance (QA). We propose methods for estimation of fluence complexity in an IMRT field based on dose gradients and investigate the relation between results of gamma analysis and this quantity. If there is a relation, it might be possible to only verify the most complex field of a plan. We determine the average fluence complexity in clinical fields and design a test fluence corresponding to this amount of complexity which might be used in daily QA and potentially replace patient-related verification. Its applicability is assessed in clinical practice. The relation between fluence complexity and results of gamma analysis has been confirmed for plans but not for single fields. There is an agreement between the suggested test fluence and clinical fields in the average gamma parameter. A critical value of average gamma has been specified for the test fluence as a criterion for distinguishing between poorly and well deliverable plans. It will not be possible to only verify the most complex field of a plan but verification of individual plans could be replaced by a morning check of the suggested test fluence, together with a well-established set of QA tests. (Author)

  6. Formal verification of complex properties on PLC programs

    CERN Document Server

    Darvas, D; Voros, A; Bartha, T; Blanco Vinuela, E; Gonzalez Suarez, V M

    2014-01-01

    Formal verification has become a recommended practice in the safety-critical application areas. However, due to the complexity of practical control and safety systems, the state space explosion often prevents the use of formal analysis. In this paper we extend our former verification methodology with effective property preserving reduction techniques. For this purpose we developed general rule-based reductions and a customized version of the Cone of Influence (COI) reduction. Using these methods, the verification of complex requirements formalised with temporal logics (e.g. CTL, LTL) can be orders of magnitude faster. We use the NuSMV model checker on a real-life PLC program from CERN to demonstrate the performance of our reduction techniques.

  7. Calibration and verification of surface contamination meters --- Procedures and techniques

    International Nuclear Information System (INIS)

    Schuler, C; Butterweck, G.; Wernli, C.; Bochud, F.; Valley, J.-F.

    2007-03-01

    A standardised measurement procedure for surface contamination meters (SCM) is presented. The procedure aims at rendering surface contamination measurements to be simply and safely interpretable. Essential for the approach is the introduction and common use of the radionuclide specific quantity 'guideline value' specified in the Swiss Radiation Protection Ordinance as unit for the measurement of surface activity. The according radionuclide specific 'guideline value count rate' can be summarized as verification reference value for a group of radionuclides ('basis guideline value count rate'). The concept can be generalized for SCM of the same type or for SCM of different types using he same principle of detection. A SCM multi source calibration technique is applied for the determination of the instrument efficiency. Four different electron radiation energy regions, four different photon radiation energy regions and an alpha radiation energy region are represented by a set of calibration sources built according to ISO standard 8769-2. A guideline value count rate representing the activity per unit area of a surface contamination of one guideline value can be calculated for any radionuclide using instrument efficiency, radionuclide decay data, contamination source efficiency, guideline value averaging area (100 cm 2 ), and radionuclide specific guideline value. n this way, instrument responses for the evaluation of surface contaminations are obtained for radionuclides without available calibration sources as well as for short-Iived radionuclides, for which the continuous replacement of certified calibration sources can lead to unreasonable costs. SCM verification is based on surface emission rates of reference sources with an active area of 100 cm 2 . The verification for a given list of radionuclides is based on the radionuclide specific quantity guideline value count rate. Guideline value count rates for groups of radionuclides can be represented within the maximum

  8. Predictive Surface Complexation Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Sverjensky, Dimitri A. [Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Earth and Planetary Sciences

    2016-11-29

    Surface complexation plays an important role in the equilibria and kinetics of processes controlling the compositions of soilwaters and groundwaters, the fate of contaminants in groundwaters, and the subsurface storage of CO2 and nuclear waste. Over the last several decades, many dozens of individual experimental studies have addressed aspects of surface complexation that have contributed to an increased understanding of its role in natural systems. However, there has been no previous attempt to develop a model of surface complexation that can be used to link all the experimental studies in order to place them on a predictive basis. Overall, my research has successfully integrated the results of the work of many experimentalists published over several decades. For the first time in studies of the geochemistry of the mineral-water interface, a practical predictive capability for modeling has become available. The predictive correlations developed in my research now enable extrapolations of experimental studies to provide estimates of surface chemistry for systems not yet studied experimentally and for natural and anthropogenically perturbed systems.

  9. Verification and application of beam steering Phased Array UT technique for complex structures

    International Nuclear Information System (INIS)

    Yamamoto, Setsu; Miura, Takahiro; Semboshi, Jun; Ochiai, Makoto; Mitsuhashi, Tadahiro; Adachi, Hiroyuki; Yamamoto, Satoshi

    2013-01-01

    Phased Array Ultrasonic Testing (PAUT) techniques for complex geometries are greatly progressing. We developed an immersion PAUT which is suitable for complex surface profiles such as nozzles and deformed welded areas. Furthermore, we have developed a shape adaptive beam steering technique for 3D complex surface structures with conventional array probe and flexible coupling gel which makes the immersion beam forming technique usable under dry conditions. This system consists of 3 steps. Step1 is surface profile measurement which based on 3D Synthesis Aperture Focusing Technique (SAFT), Step2 is delay law calculation which could take into account the measured 3D surface profiles and steer a shape adjusted ultrasonic beam, Step3 is shape adjusted B-scope construction. In this paper, verification results of property of this PAUT system using R60 curved specimen and nozzle shaped specimen which simulated actual BWR structure. (author)

  10. Measurement of complex surfaces

    International Nuclear Information System (INIS)

    Brown, G.M.

    1993-05-01

    Several of the components used in coil fabrication involve complex surfaces and dimensions that are not well suited to measurements using conventional dimensional measuring equipment. Some relatively simple techniques that are in use in the SSCL Magnet Systems Division (MSD) for incoming inspection will be described, with discussion of their suitability for specific applications. Components that are submitted for MSD Quality Assurance (QA) dimensional inspection may be divided into two distinct categories; the first category involves components for which there is an approved drawing and for which all nominal dimensions are known; the second category involves parts for which 'reverse engineering' is required, the part is available but there are no available drawings or dimensions. This second category typically occurs during development of coil end parts and coil turn filler parts where it is necessary to manually shape the part and then measure it to develop the information required to prepare a drawing for the part

  11. Inspection and verification of waste packages for near surface disposal

    International Nuclear Information System (INIS)

    2000-01-01

    Extensive experience has been gained with various disposal options for low and intermediate level waste at or near surface disposal facilities. Near surface disposal is based on proven and well demonstrated technologies. To ensure the safety of near surface disposal facilities when available technologies are applied, it is necessary to control and assure the quality of the repository system's performance, which includes waste packages, engineered features and natural barriers, as well as siting, design, construction, operation, closure and institutional controls. Recognizing the importance of repository performance, the IAEA is producing a set of technical publications on quality assurance and quality control (QA/QC) for waste disposal to provide Member States with technical guidance and current information. These publications cover issues on the application of QA/QC programmes to waste disposal, long term record management, and specific QA/QC aspects of waste packaging, repository design and R and D. Waste package QA/QC is especially important because the package is the primary barrier to radionuclide release from a disposal facility. Waste packaging also involves interface issues between the waste generator and the disposal facility operator. Waste should be packaged by generators to meet waste acceptance requirements set for a repository or disposal system. However, it is essential that the disposal facility operator ensure that waste packages conform with disposal facility acceptance requirements. Demonstration of conformance with disposal facility acceptance requirements can be achieved through the systematic inspection and verification of waste packages at both the waste generator's site and at the disposal facility, based on a waste package QA/QC programme established by the waste generator and approved by the disposal operator. However, strategies, approaches and the scope of inspection and verification will be somewhat different from country to country

  12. Automation bias and verification complexity: a systematic review.

    Science.gov (United States)

    Lyell, David; Coiera, Enrico

    2017-03-01

    While potentially reducing decision errors, decision support systems can introduce new types of errors. Automation bias (AB) happens when users become overreliant on decision support, which reduces vigilance in information seeking and processing. Most research originates from the human factors literature, where the prevailing view is that AB occurs only in multitasking environments. This review seeks to compare the human factors and health care literature, focusing on the apparent association of AB with multitasking and task complexity. EMBASE, Medline, Compendex, Inspec, IEEE Xplore, Scopus, Web of Science, PsycINFO, and Business Source Premiere from 1983 to 2015. Evaluation studies where task execution was assisted by automation and resulted in errors were included. Participants needed to be able to verify automation correctness and perform the task manually. Tasks were identified and grouped. Task and automation type and presence of multitasking were noted. Each task was rated for its verification complexity. Of 890 papers identified, 40 met the inclusion criteria; 6 were in health care. Contrary to the prevailing human factors view, AB was found in single tasks, typically involving diagnosis rather than monitoring, and with high verification complexity. The literature is fragmented, with large discrepancies in how AB is reported. Few studies reported the statistical significance of AB compared to a control condition. AB appears to be associated with the degree of cognitive load experienced in decision tasks, and appears to not be uniquely associated with multitasking. Strategies to minimize AB might focus on cognitive load reduction. © The Author 2016. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  13. Machining of Complex Sculptured Surfaces

    CERN Document Server

    2012-01-01

    The machining of complex sculptured surfaces is a global technological topic in modern manufacturing with relevance in both industrialized and emerging in countries particularly within the moulds and dies sector whose applications include highly technological industries such as the automotive and aircraft industry. Machining of Complex Sculptured Surfaces considers new approaches to the manufacture of moulds and dies within these industries. The traditional technology employed in the manufacture of moulds and dies combined conventional milling and electro-discharge machining (EDM) but this has been replaced with  high-speed milling (HSM) which has been applied in roughing, semi-finishing and finishing of moulds and dies with great success. Machining of Complex Sculptured Surfaces provides recent information on machining of complex sculptured surfaces including modern CAM systems and process planning for three and five axis machining as well as explanations of the advantages of HSM over traditional methods ra...

  14. One-time pad, complexity of verification of keys, and practical security of quantum cryptography

    Energy Technology Data Exchange (ETDEWEB)

    Molotkov, S. N., E-mail: sergei.molotkov@gmail.com [Russian Academy of Sciences, Institute of Solid State Physics (Russian Federation)

    2016-11-15

    A direct relation between the complexity of the complete verification of keys, which is one of the main criteria of security in classical systems, and a trace distance used in quantum cryptography is demonstrated. Bounds for the minimum and maximum numbers of verification steps required to determine the actual key are obtained.

  15. One-time pad, complexity of verification of keys, and practical security of quantum cryptography

    International Nuclear Information System (INIS)

    Molotkov, S. N.

    2016-01-01

    A direct relation between the complexity of the complete verification of keys, which is one of the main criteria of security in classical systems, and a trace distance used in quantum cryptography is demonstrated. Bounds for the minimum and maximum numbers of verification steps required to determine the actual key are obtained.

  16. Solid waste operations complex engineering verification program plan

    International Nuclear Information System (INIS)

    Bergeson, C.L.

    1994-01-01

    This plan supersedes, but does not replace, the previous Waste Receiving and Processing/Solid Waste Engineering Development Program Plan. In doing this, it does not repeat the basic definitions of the various types or classes of development activities nor provide the rigorous written description of each facility and assign the equipment to development classes. The methodology described in the previous document is still valid and was used to determine the types of verification efforts required. This Engineering Verification Program Plan will be updated on a yearly basis. This EVPP provides programmatic definition of all engineering verification activities for the following SWOC projects: (1) Project W-026 - Waste Receiving and Processing Facility Module 1; (2) Project W-100 - Waste Receiving and Processing Facility Module 2A; (3) Project W-112 - Phase V Storage Facility; and (4) Project W-113 - Solid Waste Retrieval. No engineering verification activities are defined for Project W-112 as no verification work was identified. The Acceptance Test Procedures/Operational Test Procedures will be part of each project's Title III operation test efforts. The ATPs/OTPs are not covered by this EVPP

  17. Land Surface Verification Toolkit (LVT) - A Generalized Framework for Land Surface Model Evaluation

    Science.gov (United States)

    Kumar, Sujay V.; Peters-Lidard, Christa D.; Santanello, Joseph; Harrison, Ken; Liu, Yuqiong; Shaw, Michael

    2011-01-01

    Model evaluation and verification are key in improving the usage and applicability of simulation models for real-world applications. In this article, the development and capabilities of a formal system for land surface model evaluation called the Land surface Verification Toolkit (LVT) is described. LVT is designed to provide an integrated environment for systematic land model evaluation and facilitates a range of verification approaches and analysis capabilities. LVT operates across multiple temporal and spatial scales and employs a large suite of in-situ, remotely sensed and other model and reanalysis datasets in their native formats. In addition to the traditional accuracy-based measures, LVT also includes uncertainty and ensemble diagnostics, information theory measures, spatial similarity metrics and scale decomposition techniques that provide novel ways for performing diagnostic model evaluations. Though LVT was originally designed to support the land surface modeling and data assimilation framework known as the Land Information System (LIS), it also supports hydrological data products from other, non-LIS environments. In addition, the analysis of diagnostics from various computational subsystems of LIS including data assimilation, optimization and uncertainty estimation are supported within LVT. Together, LIS and LVT provide a robust end-to-end environment for enabling the concepts of model data fusion for hydrological applications. The evolving capabilities of LVT framework are expected to facilitate rapid model evaluation efforts and aid the definition and refinement of formal evaluation procedures for the land surface modeling community.

  18. Land surface Verification Toolkit (LVT) - a generalized framework for land surface model evaluation

    Science.gov (United States)

    Kumar, S. V.; Peters-Lidard, C. D.; Santanello, J.; Harrison, K.; Liu, Y.; Shaw, M.

    2012-06-01

    Model evaluation and verification are key in improving the usage and applicability of simulation models for real-world applications. In this article, the development and capabilities of a formal system for land surface model evaluation called the Land surface Verification Toolkit (LVT) is described. LVT is designed to provide an integrated environment for systematic land model evaluation and facilitates a range of verification approaches and analysis capabilities. LVT operates across multiple temporal and spatial scales and employs a large suite of in-situ, remotely sensed and other model and reanalysis datasets in their native formats. In addition to the traditional accuracy-based measures, LVT also includes uncertainty and ensemble diagnostics, information theory measures, spatial similarity metrics and scale decomposition techniques that provide novel ways for performing diagnostic model evaluations. Though LVT was originally designed to support the land surface modeling and data assimilation framework known as the Land Information System (LIS), it supports hydrological data products from non-LIS environments as well. In addition, the analysis of diagnostics from various computational subsystems of LIS including data assimilation, optimization and uncertainty estimation are supported within LVT. Together, LIS and LVT provide a robust end-to-end environment for enabling the concepts of model data fusion for hydrological applications. The evolving capabilities of LVT framework are expected to facilitate rapid model evaluation efforts and aid the definition and refinement of formal evaluation procedures for the land surface modeling community.

  19. Verification and synthesis of optimal decision strategies for complex systems

    Energy Technology Data Exchange (ETDEWEB)

    Summers, S. J.

    2013-07-01

    Complex systems make a habit of disagreeing with the mathematical models strategically designed to capture their behavior. A recursive process ensues where data is used to gain insight into the disagreement. A simple model may give way to a model with hybrid dynamics. A deterministic model may give way to a model with stochastic dynamics. In many cases, the modeling framework that sufficiently characterises the system is both hybrid and stochastic; these systems are referred to as stochastic hybrid systems. This dissertation considers the stochastic hybrid system framework for modeling complex systems and provides mathematical methods for analysing, and synthesizing decision laws for, such systems. We first propose a stochastic reach-avoid problem for discrete time stochastic hybrid systems. In particular, we present a dynamic programming based solution to a probabilistic reach-avoid problem for a controlled discrete time stochastic hybrid system. We address two distinct interpretations of the reach-avoid problem via stochastic optimal control. In the first case, a sum-multiplicative cost function is introduced along with a corresponding dynamic recursion that quantifies the probability of hitting a target set at some point during a finite time horizon, while avoiding an unsafe set at all preceding time steps. In the second case, we introduce a multiplicative cost function and a dynamic recursion that quantifies the probability of hitting a target set at the terminal time, while avoiding an unsafe set at all preceding time steps. In each case, optimal reach-avoid control policies are derived as the solution to an optimal control problem via dynamic programming. We next introduce an extension of the reach-avoid problem where we consider the verification of discrete time stochastic hybrid systems when there exists uncertainty in the reachability specifications themselves. A sum multiplicative cost function is introduced along with a corresponding dynamic recursion

  20. Verification and synthesis of optimal decision strategies for complex systems

    International Nuclear Information System (INIS)

    Summers, S. J.

    2013-01-01

    Complex systems make a habit of disagreeing with the mathematical models strategically designed to capture their behavior. A recursive process ensues where data is used to gain insight into the disagreement. A simple model may give way to a model with hybrid dynamics. A deterministic model may give way to a model with stochastic dynamics. In many cases, the modeling framework that sufficiently characterises the system is both hybrid and stochastic; these systems are referred to as stochastic hybrid systems. This dissertation considers the stochastic hybrid system framework for modeling complex systems and provides mathematical methods for analysing, and synthesizing decision laws for, such systems. We first propose a stochastic reach-avoid problem for discrete time stochastic hybrid systems. In particular, we present a dynamic programming based solution to a probabilistic reach-avoid problem for a controlled discrete time stochastic hybrid system. We address two distinct interpretations of the reach-avoid problem via stochastic optimal control. In the first case, a sum-multiplicative cost function is introduced along with a corresponding dynamic recursion that quantifies the probability of hitting a target set at some point during a finite time horizon, while avoiding an unsafe set at all preceding time steps. In the second case, we introduce a multiplicative cost function and a dynamic recursion that quantifies the probability of hitting a target set at the terminal time, while avoiding an unsafe set at all preceding time steps. In each case, optimal reach-avoid control policies are derived as the solution to an optimal control problem via dynamic programming. We next introduce an extension of the reach-avoid problem where we consider the verification of discrete time stochastic hybrid systems when there exists uncertainty in the reachability specifications themselves. A sum multiplicative cost function is introduced along with a corresponding dynamic recursion

  1. Application of surface-enhanced Raman spectroscopy (SERS) for cleaning verification in pharmaceutical manufacture.

    Science.gov (United States)

    Corrigan, Damion K; Cauchi, Michael; Piletsky, Sergey; Mccrossen, Sean

    2009-01-01

    Cleaning verification is the process by which pharmaceutical manufacturing equipment is determined as sufficiently clean to allow manufacture to continue. Surface-enhanced Raman spectroscopy (SERS) is a very sensitive spectroscopic technique capable of detection at levels appropriate for cleaning verification. In this paper, commercially available Klarite SERS substrates were employed in order to obtain the necessary enhancement of signal for the identification of chemical species at concentrations of 1 to 10 ng/cm2, which are relevant to cleaning verification. The SERS approach was combined with principal component analysis in the identification of drug compounds recovered from a contaminated steel surface.

  2. The step complexity measure for emergency operating procedures: measure verification

    International Nuclear Information System (INIS)

    Park, Jinkyun; Jung, Wondea; Ha, Jaejoo; Park, Changkue

    2002-01-01

    In complex systems, such as nuclear power plants (NPPs) or airplane control systems, human errors play a major role in many accidents. Therefore, to prevent an occurrence of accidents or to ensure system safety, extensive effort has been made to identify significant factors that can cause human errors. According to related studies, written manuals or operating procedures are revealed as one of the most important factors, and the understandability is pointed out as one of the major reasons for procedure-related human errors. Many qualitative checklists are suggested to evaluate emergency operating procedures (EOPs) of NPPs. However, since qualitative evaluations using checklists have some drawbacks, a quantitative measure that can quantify the complexity of EOPs is very necessary to compensate for them. In order to quantify the complexity of steps included in EOPs, Park et al. suggested the step complexity (SC) measure. In addition, to ascertain the appropriateness of the SC measure, averaged step performance time data obtained from emergency training records for the loss of coolant accident and the excess steam dump event were compared with estimated SC scores. Although averaged step performance time data show good correlation with estimated SC scores, conclusions for some important issues that have to be clarified to ensure the appropriateness of the SC measure were not properly drawn because of lack of backup data. In this paper, to clarify remaining issues, additional activities to verify the appropriateness of the SC measure are performed using averaged step performance time data obtained from emergency training records. The total number of available records is 36, and training scenarios are the steam generator tube rupture and the loss of all feedwater. The number of scenarios is 18 each. From these emergency training records, averaged step performance time data for 30 steps are retrieved. As the results, the SC measure shows statistically meaningful

  3. Complex Systems Models and Their Applications: Towards a New Science of Verification, Validation & Uncertainty Quantification

    Energy Technology Data Exchange (ETDEWEB)

    Tsao, Jeffrey Y. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Trucano, Timothy G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kleban, Stephen D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Naugle, Asmeret Bier [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Verzi, Stephen Joseph [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Swiler, Laura Painton [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Johnson, Curtis M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Smith, Mark A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Flanagan, Tatiana Paz [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Vugrin, Eric D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gabert, Kasimir Georg [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lave, Matthew Samuel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Chen, Wei [Northwestern Univ., Evanston, IL (United States); DeLaurentis, Daniel [Purdue Univ., West Lafayette, IN (United States); Hubler, Alfred [Univ. of Illinois, Urbana, IL (United States); Oberkampf, Bill [WLO Consulting, Austin, TX (United States)

    2016-08-01

    This report contains the written footprint of a Sandia-hosted workshop held in Albuquerque, New Mexico, June 22-23, 2016 on “Complex Systems Models and Their Applications: Towards a New Science of Verification, Validation and Uncertainty Quantification,” as well as of pre-work that fed into the workshop. The workshop’s intent was to explore and begin articulating research opportunities at the intersection between two important Sandia communities: the complex systems (CS) modeling community, and the verification, validation and uncertainty quantification (VVUQ) community The overarching research opportunity (and challenge) that we ultimately hope to address is: how can we quantify the credibility of knowledge gained from complex systems models, knowledge that is often incomplete and interim, but will nonetheless be used, sometimes in real-time, by decision makers?

  4. Radiation planning in small complex lesions and experimental verification

    International Nuclear Information System (INIS)

    Jess-Hempen, A.; Wowra, B.; Mack, A.; Kreiner, H.J.; Heck, B.

    2003-01-01

    The Gamma Knife is used as a sterotactic tool for the conformal treatment of very small, complex-shape cranial lesions. The combination of planning software and treatment equipment enables a highly-precise conformal dose distribution and positioning. The purpose of the present study was to experimentally verify the precision actually achievable in case of extremely irregular, small target volumes. For this purpose, a complete treatment procedure was performed using a standard head phantom complemented with a specially developed insert that simulates an L-shaped lesion. The spatial precision of the irradiation was recorded by means of high-resolution film dosimetry using GafChromic TM films. The analysis of the films showed for the film in the center plane an excellent conformity of the 75% isodose line used to circumscribe the lesion. A very good agreement between planning and measurement resulted also for isodose lines residing outside of the target volume. (orig.) [de

  5. Computational Complexity of Combinatorial Surfaces

    NARCIS (Netherlands)

    Vegter, Gert; Yap, Chee K.

    1990-01-01

    We investigate the computational problems associated with combinatorial surfaces. Specifically, we present an algorithm (based on the Brahana-Dehn-Heegaard approach) for transforming the polygonal schema of a closed triangulated surface into its canonical form in O(n log n) time, where n is the

  6. An index of floodplain surface complexity

    Science.gov (United States)

    Scown, Murray W.; Thoms, Martin C.; DeJager, Nathan R.

    2016-01-01

    Floodplain surface topography is an important component of floodplain ecosystems. It is the primary physical template upon which ecosystem processes are acted out, and complexity in this template can contribute to the high biodiversity and productivity of floodplain ecosystems. There has been a limited appreciation of floodplain surface complexity because of the traditional focus on temporal variability in floodplains as well as limitations to quantifying spatial complexity. An index of floodplain surface complexity (FSC) is developed in this paper and applied to eight floodplains from different geographic settings. The index is based on two key indicators of complexity, variability in surface geometry (VSG) and the spatial organisation of surface conditions (SPO), and was determined at three sampling scales. FSC, VSG, and SPO varied between the eight floodplains and these differences depended upon sampling scale. Relationships between these measures of spatial complexity and seven geomorphological and hydrological drivers were investigated. There was a significant decline in all complexity measures with increasing floodplain width, which was explained by either a power, logarithmic, or exponential function. There was an initial rapid decline in surface complexity as floodplain width increased from 1.5 to 5 km, followed by little change in floodplains wider than 10 km. VSG also increased significantly with increasing sediment yield. No significant relationships were determined between any of the four hydrological variables and floodplain surface complexity.

  7. Wind turbine power performance verification in complex terrain and wind farms

    DEFF Research Database (Denmark)

    Friis Pedersen, Troels; Gjerding, S.; Enevoldsen, P.

    2002-01-01

    is a power performance verification procedure for individual wind turbines. The third is a power performance measurement procedure of whole wind farms, and the fourth is a power performance measurement procedurefor non-grid (small) wind turbines. This report presents work that was made to support the basis......The IEC/EN 61400-12 Ed 1 standard for wind turbine power performance testing is being revised. The standard will be divided into four documents. The first one of these is more or less a revision of the existing document on power performance measurementson individual wind turbines. The second one...... then been investigated in more detail. The work has given rise to a range of conclusionsand recommendations regarding: guaranties on power curves in complex terrain; investors and bankers experience with verification of power curves; power performance in relation to regional correction curves for Denmark...

  8. Complex-Wide Waste Flow Analysis V1.0 verification and validation report

    International Nuclear Information System (INIS)

    Hsu, K.M.; Lundeen, A.S.; Oswald, K.B.; Shropshire, D.E.; Robinson, J.M.; West, W.H.

    1997-01-01

    The complex-wide waste flow analysis model (CWWFA) was developed to assist the Department of Energy (DOE) Environmental Management (EM) Office of Science and Technology (EM-50) to evaluate waste management scenarios with emphasis on identifying and prioritizing technology development opportunities to reduce waste flows and public risk. In addition, the model was intended to support the needs of the Complex-Wide Environmental Integration (EMI) team supporting the DOE's Accelerating Cleanup: 2006 Plan. CWWFA represents an integrated environmental modeling system that covers the life cycle of waste management activities including waste generation, interim process storage, retrieval, characterization and sorting, waste preparation and processing, packaging, final interim storage, transport, and disposal at a final repository. The CWWFA shows waste flows through actual site-specific and facility-specific conditions. The system requirements for CWWFA are documented in the Technical Requirements Document (TRD). The TRD is intended to be a living document that will be modified over the course of the execution of CWWFA development. Thus, it is anticipated that CWWFA will continue to evolve as new requirements are identified (i.e., transportation, small sites, new streams, etc.). This report provides a documented basis for system verification of CWWFA requirements. System verification is accomplished through formal testing and evaluation to ensure that all performance requirements as specified in the TRD have been satisfied. A Requirement Verification Matrix (RVM) was used to map the technical requirements to the test procedures. The RVM is attached as Appendix A. Since February of 1997, substantial progress has been made toward development of the CWWFA to meet the system requirements. This system verification activity provides a baseline on system compliance to requirements and also an opportunity to reevaluate what requirements need to be satisfied in FY-98

  9. Field verification of ADCP surface gravity wave elevation spectra

    NARCIS (Netherlands)

    Hoitink, A.J.F.; Peters, H.C.; Schroevers, M.

    2007-01-01

    Acoustic Doppler current profilers (ADCPs) can measure orbital velocities induced by surface gravity waves, yet the ADCP estimates of these velocities are subject to a relatively high noise level. The present paper introduces a linear filtration technique to significantly reduce the influence of

  10. Chequered surfaces and complex matrices

    International Nuclear Information System (INIS)

    Morris, T.R.; Southampton Univ.

    1991-01-01

    We investigate a large-N matrix model involving general complex matrices. It can be reinterpreted as a model of two hermitian matrices with specific couplings, and as a model of positive definite hermitian matrices. Large-N perturbation theory generates dynamical triangulations in which the triangles can be chequered (i.e. coloured so that neighbours are opposite colours). On a sphere there is a simple relation between such triangulations and those generated by the single hermitian matrix model. For the torus (and a quartic potential) we solve the counting problem for the number of triangulations that cannot be quechered. The critical physics of chequered triangulations is the same as that of the hermitian matrix model. We show this explicitly by solving non-perturbatively pure two-dimensional ''chequered'' gravity. The interpretative framework given here applies to a number of other generalisations of the hermitian matrix model. (orig.)

  11. Surface coatings as xenon diffusion barriers on plastic scintillators : Improving Nuclear-Test-Ban Treaty verification

    OpenAIRE

    Bläckberg, Lisa

    2011-01-01

    This thesis investigates the ability of transparent surface coatings to reduce xenon diffusion into plastic scintillators. The motivation for the work is improved radioxenon monitoring equipment, used with in the framework of the verification regime of the Comprehensive Nuclear-Test-Ban Treaty. A large part of the equipment used in this context incorporates plastic scintillators which are in direct contact with the radioactive gas to be detected. One problem with such setup is that radioxenon...

  12. Complexation of carboxylate on smectite surfaces.

    Science.gov (United States)

    Liu, Xiandong; Lu, Xiancai; Zhang, Yingchun; Zhang, Chi; Wang, Rucheng

    2017-07-19

    We report a first principles molecular dynamics (FPMD) study of carboxylate complexation on clay surfaces. By taking acetate as a model carboxylate, we investigate its inner-sphere complexes adsorbed on clay edges (including (010) and (110) surfaces) and in interlayer space. Simulations show that acetate forms stable monodentate complexes on edge surfaces and a bidentate complex with Ca 2+ in the interlayer region. The free energy calculations indicate that the complexation on edge surfaces is slightly more stable than in interlayer space. By integrating pK a s and desorption free energies of Al coordinated water calculated previously (X. Liu, X. Lu, E. J. Meijer, R. Wang and H. Zhou, Geochim. Cosmochim. Acta, 2012, 81, 56-68; X. Liu, J. Cheng, M. Sprik, X. Lu and R. Wang, Geochim. Cosmochim. Acta, 2014, 140, 410-417), the pH dependence of acetate complexation has been revealed. It shows that acetate forms inner-sphere complexes on (110) in a very limited mildly acidic pH range while it can complex on (010) in the whole common pH range. The results presented in this study form a physical basis for understanding the geochemical processes involving clay-organics interactions.

  13. The effect of two complexity factors on the performance of emergency tasks-An experimental verification

    International Nuclear Information System (INIS)

    Park, Jinkyun; Jung, Wondea; Jung, Kwangtae

    2008-01-01

    It is well known that the use of procedures is very important in securing the safety of process systems, since good procedures effectively guide human operators by providing 'what should be done' and 'how to do it', especially under stressful conditions. At the same time, it has been emphasized that the use of complicated procedures could drastically impair operators' performance. This means that a systematic approach that can properly evaluate the complexity of procedures is indispensable for minimizing the side effects of complicated procedures. For this reason, Park et al. have developed a task complexity measure called TACOM that can be used to quantify the complexity of tasks stipulated in emergency operating procedures (EOPs) of nuclear power plants (NPPs). The TACOM measure consists of five sub-measures that can cover five important factors making the performance of emergency tasks complicated. However, a verification activity for two kinds of complexity factors-the level of abstraction hierarchy (AH) and engineering decision (ED)-seems to be insufficient. In this study, therefore, an experiment is conducted by using a low-fidelity simulator in order to clarify the appropriateness of these complexity factors. As a result, it seems that subjects' performance data are affected by the level of AH as well as ED. Therefore it is anticipate that both the level of AH and ED will play an important role in evaluating the complexity of EOPs

  14. Wind turbine power performance verification in complex terrain and wind farms

    Energy Technology Data Exchange (ETDEWEB)

    Friis Pedersen, T.; Gjerding, S.; Ingham, P.; Enevoldsen, P.; Kjaer Hansen, J.; Kanstrup Joergensen, H.

    2002-04-01

    The IEC/EN 61400-12 Ed 1 standard for wind turbine power performance testing is being revised. The standard will be divided into four documents. The first one of these is more or less a revision of the existing document on power performance measurements on individual wind turbines. The second one is a power performance verification procedure for individual wind turbines. The third is a power performance measurement procedure of whole wind farms, and the fourth is a power performance measurement procedure for non-grid (small) wind turbines. This report presents work that was made to support the basis for this standardisation work. The work addressed experience from several national and international research projects and contractual and field experience gained within the wind energy community on this matter. The work was wide ranging and addressed 'grey' areas of knowledge regarding existing methodologies, which has then been investigated in more detail. The work has given rise to a range of conclusions and recommendations regarding: guaranties on power curves in complex terrain; investors and bankers experience with verification of power curves; power performance in relation to regional correction curves for Denmark; anemometry and the influence of inclined flow. (au)

  15. Holographic subregion complexity for singular surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Bakhshaei, Elaheh [Isfahan University of Technology, Department of Physics, Isfahan (Iran, Islamic Republic of); Mollabashi, Ali [Institute for Research in Fundamental Sciences (IPM), School of Physics, Tehran (Iran, Islamic Republic of); Shirzad, Ahmad [Isfahan University of Technology, Department of Physics, Isfahan (Iran, Islamic Republic of); Institute for Research in Fundamental Sciences (IPM), School of Particles and Accelerators, Tehran (Iran, Islamic Republic of)

    2017-10-15

    Recently holographic prescriptions were proposed to compute the quantum complexity of a given state in the boundary theory. A specific proposal known as 'holographic subregion complexity' is supposed to calculate the complexity of a reduced density matrix corresponding to a static subregion. We study different families of singular subregions in the dual field theory and find the divergence structure and universal terms of holographic subregion complexity for these singular surfaces. We find that there are new universal terms, logarithmic in the UV cut-off, due to the singularities of a family of surfaces including a kink in (2 + 1) dimensions and cones in even dimensional field theories. We also find examples of new divergent terms such as squared logarithm and negative powers times the logarithm of the UV cut-off parameter. (orig.)

  16. Fiction and reality in the modelling world - Balance between simplicity and complexity, calibration and identifiability, verification and falsification

    DEFF Research Database (Denmark)

    Harremoës, P.; Madsen, H.

    1999-01-01

    Where is the balance between simplicity and complexity in model prediction of urban drainage structures? The calibration/verification approach to testing of model performance gives an exaggerated sense of certainty. Frequently, the model structure and the parameters are not identifiable by calibr......Where is the balance between simplicity and complexity in model prediction of urban drainage structures? The calibration/verification approach to testing of model performance gives an exaggerated sense of certainty. Frequently, the model structure and the parameters are not identifiable...... by calibration/verification on the basis of the data series available, which generates elements of sheer guessing - unless the universality of the model is be based on induction, i.e. experience from the sum of all previous investigations. There is a need to deal more explicitly with uncertainty...

  17. Surface-complexation models for sorption onto heterogeneous surfaces

    International Nuclear Information System (INIS)

    Harvey, K.B.

    1997-10-01

    This report provides a description of the discrete-logK spectrum model, together with a description of its derivation, and of its place in the larger context of surface-complexation modelling. The tools necessary to apply the discrete-logK spectrum model are discussed, and background information appropriate to this discussion is supplied as appendices. (author)

  18. Failure of Cleaning Verification in Pharmaceutical Industry Due to Uncleanliness of Stainless Steel Surface.

    Science.gov (United States)

    Haidar Ahmad, Imad A; Blasko, Andrei

    2017-08-11

    The aim of this work is to identify the parameters that affect the recovery of pharmaceutical residues from the surface of stainless steel coupons. A series of factors were assessed, including drug product spike levels, spiking procedure, drug-excipient ratios, analyst-to-analyst variability, intraday variability, and cleaning procedure of the coupons. The lack of a well-defined procedure that consistently cleaned the coupon surface was identified as the major contributor to low and variable recoveries. Assessment of cleaning the surface of the coupons with clean-in-place solutions (CIP) gave high recovery (>90%) and reproducible results (Srel≤4%) regardless of the conditions that were assessed previously. The approach was successfully applied for cleaning verification of small molecules (MW <1,000 Da) as well as large biomolecules (MW up to 50,000 Da).

  19. COMPLEX SURFACE HARDENING OF STEEL ARTICLES

    Directory of Open Access Journals (Sweden)

    A. V. Kovalchuk

    2014-01-01

    Full Text Available The method of complex surface hardening of steel detailswas designed. The method is a compound of two processes of hardening: chemical heat treatment and physical vapor deposition (PVD of the coating. The result, achieved in this study is much higher, than in other work on this topic and is cumulative. The method designed can be used in mechanical engineering, medicine, energetics and is perspective for military and space technologies.

  20. Experimental verification of active IR stealth technology by controlling the surface temperature using a thermoelectric element

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Geon; Han, Kuk Il; Choi, Jun Hyuk; Kim, Tae Kuk [Dept. of Mechanical Engineering, Chung Ang University, Seoul (Korea, Republic of)

    2016-10-15

    In this paper, we propose a technique for IR low-observability that uses an active IR signal tuning through the real time control of the object surface temperature according to the varying background environment. This is achieved by applying the proper object surface temperature obtained to result in the minimum radiance difference between the object and the background. Experimental verification by using the thermoelectric temperature control element shows that the IR radiance contrast between the object and the background can be reduced up to 99% during the night and up to 95% during the day time as compared to the un-tuned original radiance contrast values. The stealth technology demonstrated in this paper may be applied for many military systems needed for the IR stealth performance when a suitable temperature control unit is developed.

  1. Experimental verification of active IR stealth technology by controlling the surface temperature using a thermoelectric element

    International Nuclear Information System (INIS)

    Kim, Dong Geon; Han, Kuk Il; Choi, Jun Hyuk; Kim, Tae Kuk

    2016-01-01

    In this paper, we propose a technique for IR low-observability that uses an active IR signal tuning through the real time control of the object surface temperature according to the varying background environment. This is achieved by applying the proper object surface temperature obtained to result in the minimum radiance difference between the object and the background. Experimental verification by using the thermoelectric temperature control element shows that the IR radiance contrast between the object and the background can be reduced up to 99% during the night and up to 95% during the day time as compared to the un-tuned original radiance contrast values. The stealth technology demonstrated in this paper may be applied for many military systems needed for the IR stealth performance when a suitable temperature control unit is developed

  2. Transitioning Enhanced Land Surface Initialization and Model Verification Capabilities to the Kenya Meteorological Department (KMD)

    Science.gov (United States)

    Case, Jonathan L.; Mungai, John; Sakwa, Vincent; Zavodsky, Bradley T.; Srikishen, Jayanthi; Limaye, Ashutosh; Blankenship, Clay B.

    2016-01-01

    Flooding, severe weather, and drought are key forecasting challenges for the Kenya Meteorological Department (KMD), based in Nairobi, Kenya. Atmospheric processes leading to convection, excessive precipitation and/or prolonged drought can be strongly influenced by land cover, vegetation, and soil moisture content, especially during anomalous conditions and dry/wet seasonal transitions. It is thus important to represent accurately land surface state variables (green vegetation fraction, soil moisture, and soil temperature) in Numerical Weather Prediction (NWP) models. The NASA SERVIR and the Short-term Prediction Research and Transition (SPoRT) programs in Huntsville, AL have established a working partnership with KMD to enhance its regional modeling capabilities. SPoRT and SERVIR are providing experimental land surface initialization datasets and model verification capabilities for capacity building at KMD. To support its forecasting operations, KMD is running experimental configurations of the Weather Research and Forecasting (WRF; Skamarock et al. 2008) model on a 12-km/4-km nested regional domain over eastern Africa, incorporating the land surface datasets provided by NASA SPoRT and SERVIR. SPoRT, SERVIR, and KMD participated in two training sessions in March 2014 and June 2015 to foster the collaboration and use of unique land surface datasets and model verification capabilities. Enhanced regional modeling capabilities have the potential to improve guidance in support of daily operations and high-impact weather and climate outlooks over Eastern Africa. For enhanced land-surface initialization, the NASA Land Information System (LIS) is run over Eastern Africa at 3-km resolution, providing real-time land surface initialization data in place of interpolated global model soil moisture and temperature data available at coarser resolutions. Additionally, real-time green vegetation fraction (GVF) composites from the Suomi-NPP VIIRS instrument is being incorporated

  3. The virtual product-process design laboratory to manage the complexity in the verification of formulated products

    DEFF Research Database (Denmark)

    Conte, Elisa; Gani, Rafiqul; Malik, Tahir I.

    2011-01-01

    -Process Design laboratory (virtual PPD-lab) software is based on this decomposition strategy for the design of formulated liquid products. When the needed models are available in the software, the solution of formulation design/verification problems is straightforward, while when models are not available...... mixtures need to be predicted. This complexity has to be managed through decomposition of the problem into sub-problems. Each sub-problem is solved and analyzed and, from the knowledge gained, an overall evaluation of the complex chemical system representing the product is made. The virtual Product...... in the software library, they need to be developed and/or implemented. The potential of the virtual PPD-lab in managing the complexity in the verification of formulated products, after the needed models have been developed and implemented, is highlighted in this paper through a case study from industry dealing...

  4. Towards the development of a rapid, portable, surface enhanced Raman spectroscopy based cleaning verification system for the drug nelarabine.

    Science.gov (United States)

    Corrigan, Damion K; Salton, Neale A; Preston, Chris; Piletsky, Sergey

    2010-09-01

    Cleaning verification is a scientific and economic problem for the pharmaceutical industry. A large amount of potential manufacturing time is lost to the process of cleaning verification. This involves the analysis of residues on spoiled manufacturing equipment, with high-performance liquid chromatography (HPLC) being the predominantly employed analytical technique. The aim of this study was to develop a portable cleaning verification system for nelarabine using surface enhanced Raman spectroscopy (SERS). SERS was conducted using a portable Raman spectrometer and a commercially available SERS substrate to develop a rapid and portable cleaning verification system for nelarabine. Samples of standard solutions and swab extracts were deposited onto the SERS active surfaces, allowed to dry and then subjected to spectroscopic analysis. Nelarabine was amenable to analysis by SERS and the necessary levels of sensitivity were achievable. It is possible to use this technology for a semi-quantitative limits test. Replicate precision, however, was poor due to the heterogeneous drying pattern of nelarabine on the SERS active surface. Understanding and improving the drying process in order to produce a consistent SERS signal for quantitative analysis is desirable. This work shows the potential application of SERS for cleaning verification analysis. SERS may not replace HPLC as the definitive analytical technique, but it could be used in conjunction with HPLC so that swabbing is only carried out once the portable SERS equipment has demonstrated that the manufacturing equipment is below the threshold contamination level.

  5. Verification and Validation Challenges for Adaptive Flight Control of Complex Autonomous Systems

    Science.gov (United States)

    Nguyen, Nhan T.

    2018-01-01

    Autonomy of aerospace systems requires the ability for flight control systems to be able to adapt to complex uncertain dynamic environment. In spite of the five decades of research in adaptive control, the fact still remains that currently no adaptive control system has ever been deployed on any safety-critical or human-rated production systems such as passenger transport aircraft. The problem lies in the difficulty with the certification of adaptive control systems since existing certification methods cannot readily be used for nonlinear adaptive control systems. Research to address the notion of metrics for adaptive control began to appear in the recent years. These metrics, if accepted, could pave a path towards certification that would potentially lead to the adoption of adaptive control as a future control technology for safety-critical and human-rated production systems. Development of certifiable adaptive control systems represents a major challenge to overcome. Adaptive control systems with learning algorithms will never become part of the future unless it can be proven that they are highly safe and reliable. Rigorous methods for adaptive control software verification and validation must therefore be developed to ensure that adaptive control system software failures will not occur, to verify that the adaptive control system functions as required, to eliminate unintended functionality, and to demonstrate that certification requirements imposed by regulatory bodies such as the Federal Aviation Administration (FAA) can be satisfied. This presentation will discuss some of the technical issues with adaptive flight control and related V&V challenges.

  6. Measuring Software Test Verification for Complex Workpieces based on Virtual Gear Measuring Instrument

    Directory of Open Access Journals (Sweden)

    Yin Peili

    2017-08-01

    Full Text Available Validity and correctness test verification of the measuring software has been a thorny issue hindering the development of Gear Measuring Instrument (GMI. The main reason is that the software itself is difficult to separate from the rest of the measurement system for independent evaluation. This paper presents a Virtual Gear Measuring Instrument (VGMI to independently validate the measuring software. The triangular patch model with accurately controlled precision was taken as the virtual workpiece and a universal collision detection model was established. The whole process simulation of workpiece measurement is implemented by VGMI replacing GMI and the measuring software is tested in the proposed virtual environment. Taking involute profile measurement procedure as an example, the validity of the software is evaluated based on the simulation results; meanwhile, experiments using the same measuring software are carried out on the involute master in a GMI. The experiment results indicate a consistency of tooth profile deviation and calibration results, thus verifying the accuracy of gear measuring system which includes the measurement procedures. It is shown that the VGMI presented can be applied in the validation of measuring software, providing a new ideal platform for testing of complex workpiece-measuring software without calibrated artifacts.

  7. Managing Complexity in the MSL/Curiosity Entry, Descent, and Landing Flight Software and Avionics Verification and Validation Campaign

    Science.gov (United States)

    Stehura, Aaron; Rozek, Matthew

    2013-01-01

    The complexity of the Mars Science Laboratory (MSL) mission presented the Entry, Descent, and Landing systems engineering team with many challenges in its Verification and Validation (V&V) campaign. This paper describes some of the logistical hurdles related to managing a complex set of requirements, test venues, test objectives, and analysis products in the implementation of a specific portion of the overall V&V program to test the interaction of flight software with the MSL avionics suite. Application-specific solutions to these problems are presented herein, which can be generalized to other space missions and to similar formidable systems engineering problems.

  8. Near-surface monitoring strategies for geologic carbon dioxide storage verification

    Energy Technology Data Exchange (ETDEWEB)

    Oldenburg, Curtis M.; Lewicki, Jennifer L.; Hepple, Robert P.

    2003-10-31

    Geologic carbon sequestration is the capture of anthropogenic carbon dioxide (CO{sub 2}) and its storage in deep geologic formations. Geologic CO{sub 2} storage verification will be needed to ensure that CO{sub 2} is not leaking from the intended storage formation and seeping out of the ground. Because the ultimate failure of geologic CO{sub 2} storage occurs when CO{sub 2} seeps out of the ground into the atmospheric surface layer, and because elevated concentrations of CO{sub 2} near the ground surface can cause health, safety, and environmental risks, monitoring will need to be carried out in the near-surface environment. The detection of a CO{sub 2} leakage or seepage signal (LOSS) in the near-surface environment is challenging because there are large natural variations in CO{sub 2} concentrations and fluxes arising from soil, plant, and subsurface processes. The term leakage refers to CO{sub 2} migration away from the intended storage site, while seepage is defined as CO{sub 2} passing from one medium to another, for example across the ground surface. The flow and transport of CO{sub 2} at high concentrations in the near-surface environment will be controlled by its high density, low viscosity, and high solubility in water relative to air. Numerical simulations of leakage and seepage show that CO{sub 2} concentrations can reach very high levels in the shallow subsurface even for relatively modest CO{sub 2} leakage fluxes. However, once CO{sub 2} seeps out of the ground into the atmospheric surface layer, surface winds are effective at dispersing CO{sub 2} seepage. In natural ecological systems with no CO{sub 2} LOSS, near-surface CO{sub 2} fluxes and concentrations are controlled by CO{sub 2} uptake by photosynthesis, and production by root respiration, organic carbon biodegradation in soil, deep outgassing of CO{sub 2}, and by exchange of CO{sub 2} with the atmosphere. Existing technologies available for monitoring CO{sub 2} in the near-surface environment

  9. Marked fatgraph complexes and surface automorphisms

    DEFF Research Database (Denmark)

    Kuno, Yusuke; Penner, Robert; Turaev, Vladimir

    2013-01-01

    Combinatorial aspects of the Torelli-Johnson-Morita theory of surface automorphisms are extended to certain subgroups of the mapping class groups. These subgroups are defined relative to a specified homomorphism from the fundamental group of the surface onto an arbitrary group $K$. For $K$ abelia...

  10. Patient set-up verification by infrared optical localization and body surface sensing in breast radiation therapy

    International Nuclear Information System (INIS)

    Spadea, Maria Francesca; Baroni, Guido; Riboldi, Marco; Orecchia, Roberto; Pedotti, Antonio; Tagaste, Barbara; Garibaldi, Cristina

    2006-01-01

    Background and purpose: The aim of the study was to investigate the clinical application of a technique for patient set-up verification in breast cancer radiotherapy, based on the 3D localization of a hybrid configuration of surface control points. Materials and methods: An infrared optical tracker provided the 3D position of two passive markers and 10 laser spots placed around and within the irradiation field on nine patients. A fast iterative constrained minimization procedure was applied to detect and compensate patient set-up errors, through the control points registration with reference data coming from treatment plan (markers reference position, CT-based surface model). Results: The application of the corrective spatial transformation estimated by the registration procedure led to significant improvement of patient set-up. Median value of 3D errors affecting three additional verification markers within the irradiation field decreased from 5.7 to 3.5 mm. Errors variability (25-75%) decreased from 3.2 to 2.1 mm. Laser spots registration on the reference surface model was documented to contribute substantially to set-up errors compensation. Conclusions: Patient set-up verification through a hybrid set of control points and constrained surface minimization algorithm was confirmed to be feasible in clinical practice and to provide valuable information for the improvement of the quality of patient set-up, with minimal requirement of operator-dependant procedures. The technique combines conveniently the advantages of passive markers based methods and surface registration techniques, by featuring immediate and robust estimation of the set-up accuracy from a redundant dataset

  11. DESIGNING OF DEVELOPED SURFACES OF COMPLEX PARTS

    Directory of Open Access Journals (Sweden)

    S. S. Tyshchenko

    2017-04-01

    Full Text Available Purpose. The paper focuses on ensuring the rational choice of parameters of the mating surfaces of parts when designing process equipment based on the methods of artificial intelligence. Methodology. The paper considers the geometric model of a ruled developed surface, the conditions of existence of such a surface and provides a generalized algorithm for surface plotting regardless of the type of the working element or the machine-building product. One of the most common technical surfaces are the ruled ones, among which a special position is occupied by developed surfaces (thanks to their differential-parametric properties: surface tangent plane is n contact along the rectilinear generator and does not change its position in space when changing the point of contact; surfaces can be produced by bending sheet metal. These provisions enable a product manufacturer to save significant material and energy means, therefore, the development of geometric models of such surfaces is an important task. Findings. We analyzed the geometrical model of the developed surface which is incident to two guides. Experimental studies have shown the applicationprospectivity of semi-digger moldboards on moldboard plows, particularly on the double-deck ones. Taking into account the operating speed of the plow 2.8 m/s, the plant residues plowing percentage for plow with semi-digger moldboards is 98.9%, and with the digger ones – 96.1%. Originality. According to results: 1 the approaches to solving the problem of recognition of wear conditions of the tested interface, depicted by its conceptual model, were elaborated; 2 the corresponding algorithms of the computational procedures were built; 3 the mathematical model that determines the effect of the parameters of the contacting surfaces on their performance properties – linear wear rate during the normal wear and tear was developed; 4 for this model the theoretical prerequisite of use for the random mating study were

  12. New Route to Synthesize Surface Organometallic Complexes (SOMC): An Approach by Alkylating Halogenated Surface Organometallic Fragments

    KAUST Repository

    Hamieh, Ali Imad

    2017-02-01

    The aim of this thesis is to explore new simpler and efficient routes for the preparation of surface organometallic complexes (SOMC) for the transformation of small organic molecules to valuable products. The key element in this new route relies on surface alkylation of various halogenated surface coordination complexes or organometallic fragments (SOMF).

  13. New Route to Synthesize Surface Organometallic Complexes (SOMC): An Approach by Alkylating Halogenated Surface Organometallic Fragments

    KAUST Repository

    Hamieh, Ali Imad Ali

    2017-01-01

    The aim of this thesis is to explore new simpler and efficient routes for the preparation of surface organometallic complexes (SOMC) for the transformation of small organic molecules to valuable products. The key element in this new route relies on surface alkylation of various halogenated surface coordination complexes or organometallic fragments (SOMF).

  14. Verification of the anatomy and newly discovered histology of the G-spot complex.

    Science.gov (United States)

    Ostrzenski, A; Krajewski, P; Ganjei-Azar, P; Wasiutynski, A J; Scheinberg, M N; Tarka, S; Fudalej, M

    2014-10-01

    To expand the anatomical investigations of the G-spot and to assess the G-spot's characteristic histological and immunohistochemical features. An observational study. International multicentre. Eight consecutive fresh human female cadavers. Anterior vaginal wall dissections were executed and G-spot microdissections were performed. All specimens were stained with haematoxylin and eosin (H&E). The tissues of two women were selected at random for immunohistochemical staining. The primary outcome measure was to document the anatomy of the G-spot. The secondary outcome measures were to identify the histology of the G-spot and to determine whether histological samples stained with H&E are sufficient to identify the G-spot. The anatomical existence of the G-spot was identified in all women and was in a diagonal plane. In seven (87.5%) and one (12.5%) of the women the G-spot complex was found on the left or right side, respectively. The G-spot was intimately fused with vessels, creating a complex. A large tangled vein-like vascular structure resembled an arteriovenous malformation and there were a few smaller feeding arteries. A band-like structure protruded from the tail of the G-spot. The size of the G-spot varied. Histologically, the G-spot was determined as a neurovascular complex structure. The neural component contained abundant peripheral nerve bundles and a nerve ganglion. The vascular component comprised large vein-like vessels and smaller feeding arteries. Circular and longitudinal muscles covered the G-complex. The anatomy of the G-spot complex was confirmed. The histology of the G-spot presents as neurovascular tissues with a nerve ganglion. H&E staining is sufficient for the identification of the G-spot complex. © 2014 Royal College of Obstetricians and Gynaecologists.

  15. Solving complex and disordered surface structures with electron diffraction

    International Nuclear Information System (INIS)

    Van Hove, M.A.

    1987-10-01

    The past of surface structure determination with low-energy electron diffraction (LEED) will be briefly reviewed, setting the stage for a discussion of recent and future developments. The aim of these developments is to solve complex and disordered surface structures. Some efficient solutions to the theoretical and experimental problems will be presented. Since the theoretical problems dominate, the emphasis will be on theoretical approaches to the calculation of the multiple scattering of electrons through complex and disordered surfaces. 49 refs., 13 figs., 1 tab

  16. Synthesis of mixed ligand europium complexes: Verification of predicted luminescence intensification

    International Nuclear Information System (INIS)

    Lima, Nathalia B.D.; Silva, Anderson I.S.; Gonçalves, Simone M.C.; Simas, Alfredo M.

    2016-01-01

    Mixed ligand europium complexes are predicted to be more luminescent than what would be expected from their corresponding repeating ligand compounds according to a conjecture recently advanced by our research group; a conjecture that has already been validated for strongly luminescent europium complexes. In this article, we seek to further verify the validity of this conjecture for complexes which are much more symmetric, and which thus display lower levels of luminescence. Accordingly, we synthesized complexes Eu(DBM) 3 (L) 2 , and all novel mixed ligand combinations Eu(DBM) 3 (L,L') with L and L' equal to DBSO, PTSO, and TPPO. The syntheses were carried out via displacement reactions from the starting complex Eu(DBM) 3 (H 2 O) 2 , passing through the intermediates Eu(DBM) 3 (L) 2 and finally, by displacement of L by L', arriving at Eu(DBM) 3 (L,L'). The ligands L obey the following order of displacement TPPO>PTSO>DBSO>H 2 O, which had been previously described by our group. In the present article, we further show that this displacement order could have been predicted by Sparkle/RM1 thermochemical calculations. Subsequently, we determined the radiative decay rates, A rad , for all six compounds by photophysical measurements. As expected, results show that the measured A rad values for all novel mixed ligand complexes are larger than the average of the A rad values for the corresponding repeating ligand coordination compounds. In conclusion, the present article does broaden the scope of our conjecture, which enunciates that an increase in the diversity of ligands around the europium ion tends to intensify the luminescence. - Highlights: • Mixed ligand europium complexes are predicted to be more luminescent than repeating ligand ones. • Radiative decay rates increase with structural coordination asymmetry. • The non-ionic ligands displacement order in substitution reactions is TPPO>PTSO>DBSO>H 2 O. • Sparkle/RM1 correctly predicts the

  17. WE-F-16A-06: Using 3D Printers to Create Complex Phantoms for Dose Verification, Quality Assurance, and Treatment Planning System Commissioning in Radiotherapy

    International Nuclear Information System (INIS)

    Kassaee, A; Ding, X; McDonough, J; Reiche, M; Witztum, A; Teo, B

    2014-01-01

    Purpose: To use 3D printers to design and construct complex geometrical phantoms for commissioning treatment planning systems, dose calculation algorithms, quality assurance (QA), dose delivery, and patient dose verifications. Methods: In radiotherapy, complex geometrical phantoms are often required for dose verification, dose delivery and calculation algorithm validation. Presently, fabrication of customized phantoms is limited due to time, expense and challenges in machining of complex shapes. In this work, we designed and utilized 3D printers to fabricate two phantoms for QA purposes. One phantom includes hills and valleys (HV) for verification of intensity modulated radiotherapy for photons, and protons (IMRT and IMPT). The other phantom includes cylindrical cavities (CC) of various sizes for dose verification of inhomogeneities. We evaluated the HV phantoms for an IMPT beam, and the CC phantom to study various inhomogeneity configurations using photon, electron, and proton beams. Gafcromic ™ films were used to quantify the dose distributions delivered to the phantoms. Results: The HV phantom has dimensions of 12 cm × 12 cm and consists of one row and one column of five peaks with heights ranging from 2 to 5 cm. The CC phantom has a size 10 cm × 14 cm and includes 6 cylindrical cavities with length of 7.2 cm and diameters ranging from 0.6 to 1.2 cm. The IMPT evaluation using the HV phantom shows good agreement as compared to the dose distribution calculated with treatment planning system. The CC phantom also shows reasonable agreements for using different algorithms for each beam modalities. Conclusion: 3D printers with submillimiter resolutions are capable of printing complex phantoms for dose verification and QA in radiotherapy. As printing costs decrease and the technology becomes widely available, phantom design and construction will be readily available to any clinic for testing geometries that were not previously feasible

  18. Removal of arsenate by ferrihydrite via surface complexation and surface precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Xiuli [Department of Environment Engineering, College of the Environment and Ecology, and The Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, Xiamen University, Xiamen (China); Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, and The Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen (China); Peng, Changjun; Fu, Dun; Chen, Zheng [Department of Environment Engineering, College of the Environment and Ecology, and The Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, Xiamen University, Xiamen (China); Shen, Liang [Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, and The Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen (China); Li, Qingbiao [Department of Environment Engineering, College of the Environment and Ecology, and The Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, Xiamen University, Xiamen (China); Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, and The Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen (China); Ouyang, Tong, E-mail: yz3t@xmu.edu.cn [Department of Environment Engineering, College of the Environment and Ecology, and The Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, Xiamen University, Xiamen (China); Wang, Yuanpeng, E-mail: wypp@xmu.edu.cn [Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, and The Key Laboratory for Synthetic Biotechnology of Xiamen City, Xiamen University, Xiamen (China)

    2015-10-30

    Graphical abstract: - Highlights: • Surface complexation and surface precipitation of As on ferrihydrite happen at pH 3–6. • The formation of surface precipitation enhanced As(V) adsorption. • The dissolved Fe{sup 3+} had a good linear relationship with the amount of arsenate re-adsorption. - Abstract: In this study, macroscopic and spectroscopic experimental methods accurately modeled the sorption process of arsenate on ferrihydrite. EXAFS, X-ray diffraction and infrared (IR) spectroscopy indicated that the behavior of As(V) adsorption onto ferrihydrite took place mainly via surface complexation and surface precipitation at acidic pH (3.0–6.0), while the surface precipitation was dominated at longer time intervals and higher Fe{sup 3+} concentration. The macroscopic competitive adsorption experiment between arsenate with phosphate indicated two types of adsorption sites existing on the surface of ferrihydrite, i.e., non-exchangeable sites, which are responsible for a rapid surface complex formation; and exchangeable sites for a slow build-up of surface precipitates. In the slow build-up precipitates, the As(V) surface coverage (mmol/g) exhibited a good linear relationship (R{sup 2} = 0.952) with the amount of dissolved Fe{sup 3+}. Three steps are involved during the process of surface precipitation, i.e., (1) an initial uptake of As(V) via surface complexation; (2) re-adsorption of Fe{sup 3+} leaching from ferrihydrite on the surface complex; and (3) As(V) adsorption via surface complexation again and finally forming the surface precipitate.

  19. Inspector measurement verification activities

    International Nuclear Information System (INIS)

    George, R.S.; Crouch, R.

    e most difficult and complex activity facing a safeguards inspector involves the verification of measurements and the performance of the measurement system. Remeasurement is the key to measurement verification activities. Remeasurerements using the facility's measurement system provide the bulk of the data needed for determining the performance of the measurement system. Remeasurements by reference laboratories are also important for evaluation of the measurement system and determination of systematic errors. The use of these measurement verification activities in conjunction with accepted inventory verification practices provides a better basis for accepting or rejecting an inventory. (U.S.)

  20. Compact complex surfaces with geometric structures related to split quaternions

    International Nuclear Information System (INIS)

    Davidov, Johann; Grantcharov, Gueo; Mushkarov, Oleg; Yotov, Miroslav

    2012-01-01

    We study the problem of existence of geometric structures on compact complex surfaces that are related to split quaternions. These structures, called para-hypercomplex, para-hyperhermitian and para-hyperkähler, are analogs of the hypercomplex, hyperhermitian and hyperkähler structures in the definite case. We show that a compact 4-manifold carries a para-hyperkähler structure iff it has a metric of split signature together with two parallel, null, orthogonal, pointwise linearly independent vector fields. Every compact complex surface admitting a para-hyperhermitian structure has vanishing first Chern class and we show that, unlike the definite case, many of these surfaces carry infinite-dimensional families of such structures. We provide also compact examples of complex surfaces with para-hyperhermitian structures which are not locally conformally para-hyperkähler. Finally, we discuss the problem of non-existence of para-hyperhermitian structures on Inoue surfaces of type S 0 and provide a list of compact complex surfaces which could carry para-hypercomplex structures.

  1. Verification and optimization of HDR surface mould brachytherapy plans using GAFCHROMIC EBT2 film: the ideal geometric case

    International Nuclear Information System (INIS)

    Sobolewski, Matthew; Haque, Mamoon

    2011-01-01

    Full text: Surface mould brachytherapy is used to treat superficial cancers due to conformal dose distributions and rapid dose fall-off with depth. In this work, we determine the effect of varying catheter number and prescription distance on dose distributions for surface mould plans using radiochromic film. Eight surface mould plans were generated using PLATO BPS (Version 14.3.2). Measurements were taken with Gafchromic EBT2 film over depths of 5-30 mm with an Ir-192 HDR source. Films were scanned using an Epson Expression 10000 XL flatbed scanner and analysed using RIT 113 software. The EBT2 films showed good agreement with an average difference of 2.8% compared to the planning system. The dose gradient in the interval ranging ±5 mm from the prescription point showed an 80% increase from the plan with maximum catheters (II) to the minimum (3). The size and extent of local dose maxima increased when fewer catheters were used. Increasing prescription distance decreased the dose gradient with a 20% reduction in dose occurring 4 mm superficially to the prescription point when prescription distance increased from 5 to 20 mm. Gafchromic EBT2 was used successfully to evaluate surface mould brachytherapy plans and is a useful tool for dose verification checks. High dose regions ne,u' to the catheter plane can be reduced by using a larger number of catheters and the prescription distance should be adjusted as a function of treatment depth varied by mould thickness.

  2. Embedded software verification and debugging

    CERN Document Server

    Winterholer, Markus

    2017-01-01

    This book provides comprehensive coverage of verification and debugging techniques for embedded software, which is frequently used in safety critical applications (e.g., automotive), where failures are unacceptable. Since the verification of complex systems needs to encompass the verification of both hardware and embedded software modules, this book focuses on verification and debugging approaches for embedded software with hardware dependencies. Coverage includes the entire flow of design, verification and debugging of embedded software and all key approaches to debugging, dynamic, static, and hybrid verification. This book discusses the current, industrial embedded software verification flow, as well as emerging trends with focus on formal and hybrid verification and debugging approaches. Includes in a single source the entire flow of design, verification and debugging of embedded software; Addresses the main techniques that are currently being used in the industry for assuring the quality of embedded softw...

  3. One-level modeling for diagnosing surface winds over complex terrain. II - Applicability to short-range forecasting

    Science.gov (United States)

    Alpert, P.; Getenio, B.; Zak-Rosenthal, R.

    1988-01-01

    The Alpert and Getenio (1988) modification of the Mass and Dempsey (1985) one-level sigma-surface model was used to study four synoptic events that included two winter cases (a Cyprus low and a Siberian high) and two summer cases. Results of statistical verification showed that the model is not only capable of diagnosing many details of surface mesoscale flow, but might also be useful for various applications which require operative short-range prediction of the diurnal changes of high-resolution surface flow over complex terrain, for example, in locating wildland fires, determining the dispersion of air pollutants, and predicting changes in wind energy or of surface wind for low-level air flights.

  4. Performance verification of focus variation and confocal microscopes measuring tilted ultra-fine surfaces

    DEFF Research Database (Denmark)

    Quagliotti, Danilo; Baruffi, Federico; Tosello, Guido

    2016-01-01

    The behaviour of two optical instruments, scilicet a laser scanning confocal microscope and a focus-variation microscope, was investigated considering measurements of tilted surfaces. The measured samples were twelve steel artefacts for mould surface finish reference, covering Sa roughness...... parameter in the range (101—103) nm. The 3D surface texture parameters considered were Sa, Sq and Sdq. The small working distance of the confocal microscope objectives influenced the measurement setup, preventing from selecting a high tilting angle. The investigation was carried out comparing measurements...... of flat surfaces (0° tilt) with measurements of 12.5° tilted surfaces. The confocal microscope results showed a high sensitivity to tilting due to the laser beam reflection on the metal surfaces. The focus variation microscope results were more robust with respect to the considered angular variation...

  5. GEOQUIMICO : an interactive tool for comparing sorption conceptual models (surface complexation modeling versus K[D])

    International Nuclear Information System (INIS)

    Hammond, Glenn E.; Cygan, Randall Timothy

    2007-01-01

    Within reactive geochemical transport, several conceptual models exist for simulating sorption processes in the subsurface. Historically, the K D approach has been the method of choice due to ease of implementation within a reactive transport model and straightforward comparison with experimental data. However, for modeling complex sorption phenomenon (e.g. sorption of radionuclides onto mineral surfaces), this approach does not systematically account for variations in location, time, or chemical conditions, and more sophisticated methods such as a surface complexation model (SCM) must be utilized. It is critical to determine which conceptual model to use; that is, when the material variation becomes important to regulatory decisions. The geochemical transport tool GEOQUIMICO has been developed to assist in this decision-making process. GEOQUIMICO provides a user-friendly framework for comparing the accuracy and performance of sorption conceptual models. The model currently supports the K D and SCM conceptual models. The code is written in the object-oriented Java programming language to facilitate model development and improve code portability. The basic theory underlying geochemical transport and the sorption conceptual models noted above is presented in this report. Explanations are provided of how these physicochemical processes are instrumented in GEOQUIMICO and a brief verification study comparing GEOQUIMICO results to data found in the literature is given

  6. Data verification of a hardware-software complex of sounding an ionosphere and ionosonde DPS-4

    Science.gov (United States)

    Smirnov, Vladimir; Ruzhin, Yuri; Smirnova, Elena; Skobelkin, Vladimir; Tynyankin, Sergey

    Appeared in recent years, opportunities to use as a source of signals used to determine the parameters of the ionosphere, the spacecraft global navigation satellite systems GLONASS and GPS are not currently in widespread use practices ionospheric wave frequency and radio centers and dispatch services. Given the urgency of the discussed areas of research, long experiment whose purpose is to conduct a comparative analysis of the results of determining the critical frequency of F2-layer of the ionosphere in two ways - vertical sounding (ionosonde DPS-4) and radio translucence track "satellite-the Earth" with signals using GLONASS satellites and GPS was started in 2013. For a comparative analysis of the results the hardware-software complex ionospheric soundings (HSCIS) was located at territory of the Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation of the Russian Academy of Sciences. HSCIS product includes a personal computer with it specialized software, a dual-frequency navigation receiver and small receiving antenna. Used in the product receiver developed by NovAtel allows us to receive the signals of the navigation systems GPS/GLONASS and maintain their processing in real time. Location receiver determined autonomously: antenna position - 55.76o N, 37.94o E, coordinates ionosonde DPS-4 - 55.5o N, 37.3o E. In fact, both devices were in close proximity, which it allows for the identity conditions of observation. Both devices operate in real time. Ionosonde DPS- 4 gave the ionosphere parameters every 15 minutes, HSCIS - every minute. Information from both instruments displayed on the screen monitors, and recorded in the memory used by computers. Along with the numerical parameters on the monitor products HSCIS displayed time course of the critical frequency F2- layer of the ionosphere obtained from observations of the nearest navigation satellite. When limiting elevation observations 15o simultaneous use of navigation satellites can

  7. Alkali-crown ether complexes at metal surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Thontasen, Nicha; Deng, Zhitao; Rauschenbach, Stephan [Max Planck Institute for Solid State Research, Stuttgart (Germany); Levita, Giacomo [University of Trieste, Trieste (Italy); Malinowski, Nikola [Max Planck Institute for Solid State Research, Stuttgart (Germany); Bulgarian Academy of Sciences, Sofia (Bulgaria); Kern, Klaus [Max Planck Institute for Solid State Research, Stuttgart (Germany); EPFL, Lausanne (Switzerland)

    2010-07-01

    Crown ethers are polycyclic ethers which, in solution, selectively bind cations depending on the size of the ring cavity. The study of a single host-guest complex is highly desirable in order to reveal the characteristics of these specific interactions at the atomic scale. Such detailed investigation is possible at the surface where high resolution imaging tools like scanning tunneling microscopy (STM) can be applied. Here, electrospray ion beam deposition (ES-IBD) is employed for the deposition of Dibenzo-24-crown-8 (DB24C8)-H{sup +}, -Na{sup +} and -Cs{sup +} complexes on a solid surface in ultrahigh vacuum (UHV). Where other deposition techniques have not been successful, this deposition technique combines the advantages of solution based preparation of the complex ions with a highly clean and controlled deposition in UHV. Single molecular structures and the cation-binding of DB24C8 at the surface are studied in situ by STM and MALDI-MS (matrix assisted laser desorption ionization mass spectrometry). The internal structure of the complex, i.e. ring and cavity, is observable only when alkali cations are incorporated. The BD24C8-H{sup +} complex in contrast appears as a compact feature. This result is in good agreement with theoretical models based on density functional theory calculations.

  8. Dust storm events over Delhi: verification of dust AOD forecasts with satellite and surface observations

    Science.gov (United States)

    Singh, Aditi; Iyengar, Gopal R.; George, John P.

    2016-05-01

    Thar desert located in northwest part of India is considered as one of the major dust source. Dust storms originate in Thar desert during pre-monsoon season, affects large part of Indo-Gangetic plains. High dust loading causes the deterioration of the ambient air quality and degradation in visibility. Present study focuses on the identification of dust events and verification of the forecast of dust events over Delhi and western part of IG Plains, during the pre-monsoon season of 2015. Three dust events have been identified over Delhi during the study period. For all the selected days, Terra-MODIS AOD at 550 nm are found close to 1.0, while AURA-OMI AI shows high values. Dust AOD forecasts from NCMRWF Unified Model (NCUM) for the three selected dust events are verified against satellite (MODIS) and ground based observations (AERONET). Comparison of observed AODs at 550 nm from MODIS with NCUM predicted AODs reveals that NCUM is able to predict the spatial and temporal distribution of dust AOD, in these cases. Good correlation (~0.67) is obtained between the NCUM predicted dust AODs and location specific observations available from AERONET. Model under-predicted the AODs as compared to the AERONET observations. This may be mainly because the model account for only dust and no anthropogenic activities are considered. The results of the present study emphasize the requirement of more realistic representation of local dust emission in the model both of natural and anthropogenic origin, to improve the forecast of dust from NCUM during the dust events.

  9. Photoelectrochemical etching of gallium nitride surface by complexation dissolution mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Miao-Rong [Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, 215123 Suzhou (China); University of Chinese Academy of Sciences, 100049 Beijing (China); Hou, Fei; Wang, Zu-Gang; Zhang, Shao-Hui [Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, 215123 Suzhou (China); Changchun University of Science and Technology, 130022 Changchun (China); Pan, Ge-Bo, E-mail: gbpan2008@sinano.ac.cn [Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, 215123 Suzhou (China)

    2017-07-15

    Graphical abstract: GaN surface was etched by 0.3 M EDTA-2Na. The proposed complexation dissolution mechanism can be applicable to almost all neutral etchants under the prerequisite of strong light and electric field. - Highlights: • GaN surface was etched by EDTA-2Na. • GaN may be dissolved into EDTA-2Na by forming Ga–EDTA complex. • We propose the complexation dissolution mechanism for the first time. - Abstract: Gallium nitride (GaN) surface was etched by 0.3 M ethylenediamine tetraacetic acid disodium (EDTA-2Na) via photoelectrochemical etching technique. SEM images reveal the etched GaN surface becomes rough and irregular. The pore density is up to 1.9 × 10{sup 9} per square centimeter after simple acid post-treatment. The difference of XPS spectra of Ga 3d, N 1s and O 1s between the non-etched and freshly etched GaN surfaces can be attributed to the formation of Ga–EDTA complex at the etching interface between GaN and EDTA-2Na. The proposed complexation dissolution mechanism can be broadly applicable to almost all neutral etchants under the prerequisite of strong light and electric field. From the point of view of environment, safety and energy, EDTA-2Na has obvious advantages over conventionally corrosive etchants. Moreover, as the further and deeper study of such nearly neutral etchants, GaN etching technology has better application prospect in photoelectric micro-device fabrication.

  10. bcROCsurface: an R package for correcting verification bias in estimation of the ROC surface and its volume for continuous diagnostic tests.

    Science.gov (United States)

    To Duc, Khanh

    2017-11-18

    Receiver operating characteristic (ROC) surface analysis is usually employed to assess the accuracy of a medical diagnostic test when there are three ordered disease status (e.g. non-diseased, intermediate, diseased). In practice, verification bias can occur due to missingness of the true disease status and can lead to a distorted conclusion on diagnostic accuracy. In such situations, bias-corrected inference tools are required. This paper introduce an R package, named bcROCsurface, which provides utility functions for verification bias-corrected ROC surface analysis. The shiny web application of the correction for verification bias in estimation of the ROC surface analysis is also developed. bcROCsurface may become an important tool for the statistical evaluation of three-class diagnostic markers in presence of verification bias. The R package, readme and example data are available on CRAN. The web interface enables users less familiar with R to evaluate the accuracy of diagnostic tests, and can be found at http://khanhtoduc.shinyapps.io/bcROCsurface_shiny/ .

  11. Verification of surface source's characteristics using large-area 2π gas flow counter

    International Nuclear Information System (INIS)

    Abu Naser Waheed, M.M.; Mikami, S.; Kobayashi, H.; Noda, K.

    1998-09-01

    Power Reactor and Nuclear Fuel Development Corporation (PNC) has large-area 2π gas flow counter for the purpose of measuring activity of surface sources of alpha or beta ray emitter. Surface sources are used for the calibration of radiation measuring equipment for radiation control. Due to sequent use of sources, the surface of these sources are inclined to go in bad condition because of unwanted accidental incidents. For the better calibration achievement of radiation measuring instruments the rate of emission of these sources are to be checked periodically by the large-area 2π gas flow counter. In this paper described that eight U 3 O 8 surface sources were selected from many sources of PNC Tokai Works and activity of these sources was measured by the 2π gas flow counter. The results were compared with the values certified by Japan Radio Isotope Association (JRIA). It is evident from the result of comparison that the surface sources are in good condition, i.e., the sources are reliable to calibrate the radiation control instruments. (author)

  12. SU-E-J-209: Verification of 3D Surface Registration Between Stereograms and CT Images

    Energy Technology Data Exchange (ETDEWEB)

    Han, T; Gifford, K [UT MD Anderson Cancer Center, Houston, TX (United States); Smith, B [MD Anderson Cancer Center, Houston, TX (United States); Salehpour, M [M.D. Anderson Cancer Center, Houston, TX (United States)

    2014-06-01

    Purpose: Stereography can provide a visualization of the skin surface for radiation therapy patients. The aim of this study was to verify the registration algorithm in a commercial image analysis software, 3dMDVultus, for the fusion of stereograms and CT images. Methods: CT and stereographic scans were acquired of a head phantom and a deformable phantom. CT images were imported in 3dMDVultus and the surface contours were generated by threshold segmentation. Stereograms were reconstructed in 3dMDVultus. The resulting surfaces were registered with Vultus algorithm and then exported to in-house registration software and compared with four algorithms: rigid, affine, non-rigid iterative closest point (ICP) and b-spline algorithm. RMS (root-mean-square residuals of the surface point distances) error between the registered CT and stereogram surfaces was calculated and analyzed. Results: For the head phantom, the maximum RMS error between registered CT surfaces to stereogram was 6.6 mm for Vultus algorithm, whereas the mean RMS error was 0.7 mm. For the deformable phantom, the maximum RMS error was 16.2 mm for Vultus algorithm, whereas the mean RMS error was 4.4 mm. Non-rigid ICP demonstrated the best registration accuracy, as the mean of RMS errors were both within 1 mm. Conclusion: The accuracy of registration algorithm in 3dMDVultus was verified and exceeded RMS of 2 mm for deformable cases. Non-rigid ICP and b-spline algorithms improve the registration accuracy for both phantoms, especially in deformable one. For those patients whose body habitus deforms during radiation therapy, more advanced nonrigid algorithms need to be used.

  13. Surface complexation modeling of zinc sorption onto ferrihydrite.

    Science.gov (United States)

    Dyer, James A; Trivedi, Paras; Scrivner, Noel C; Sparks, Donald L

    2004-02-01

    A previous study involving lead(II) [Pb(II)] sorption onto ferrihydrite over a wide range of conditions highlighted the advantages of combining molecular- and macroscopic-scale investigations with surface complexation modeling to predict Pb(II) speciation and partitioning in aqueous systems. In this work, an extensive collection of new macroscopic and spectroscopic data was used to assess the ability of the modified triple-layer model (TLM) to predict single-solute zinc(II) [Zn(II)] sorption onto 2-line ferrihydrite in NaNO(3) solutions as a function of pH, ionic strength, and concentration. Regression of constant-pH isotherm data, together with potentiometric titration and pH edge data, was a much more rigorous test of the modified TLM than fitting pH edge data alone. When coupled with valuable input from spectroscopic analyses, good fits of the isotherm data were obtained with a one-species, one-Zn-sorption-site model using the bidentate-mononuclear surface complex, (triple bond FeO)(2)Zn; however, surprisingly, both the density of Zn(II) sorption sites and the value of the best-fit equilibrium "constant" for the bidentate-mononuclear complex had to be adjusted with pH to adequately fit the isotherm data. Although spectroscopy provided some evidence for multinuclear surface complex formation at surface loadings approaching site saturation at pH >/=6.5, the assumption of a bidentate-mononuclear surface complex provided acceptable fits of the sorption data over the entire range of conditions studied. Regressing edge data in the absence of isotherm and spectroscopic data resulted in a fair number of surface-species/site-type combinations that provided acceptable fits of the edge data, but unacceptable fits of the isotherm data. A linear relationship between logK((triple bond FeO)2Zn) and pH was found, given by logK((triple bond FeO)2Znat1g/l)=2.058 (pH)-6.131. In addition, a surface activity coefficient term was introduced to the model to reduce the ionic strength

  14. Verification of thickness and surface roughness of a thin film transparent coating

    DEFF Research Database (Denmark)

    Mohaghegh, Kamran; Hansen, Hans Nørgaard; Pranov, H.

    2013-01-01

    Thin film coatings are extremely interesting for industries, where there is a need to protect a highly accurate surface which has tight dimensional tolerances. The topic is important both in the production of new metallic tools and repair applications. In both applications it is vital to have...

  15. Design and verification of the miniature optical system for small object surface profile fast scanning

    Science.gov (United States)

    Chi, Sheng; Lee, Shu-Sheng; Huang, Jen, Jen-Yu; Lai, Ti-Yu; Jan, Chia-Ming; Hu, Po-Chi

    2016-04-01

    As the progress of optical technologies, different commercial 3D surface contour scanners are on the market nowadays. Most of them are used for reconstructing the surface profile of mold or mechanical objects which are larger than 50 mm×50 mm× 50 mm, and the scanning system size is about 300 mm×300 mm×100 mm. There are seldom optical systems commercialized for surface profile fast scanning for small object size less than 10 mm×10 mm×10 mm. Therefore, a miniature optical system has been designed and developed in this research work for this purpose. Since the most used scanning method of such system is line scan technology, we have developed pseudo-phase shifting digital projection technology by adopting projecting fringes and phase reconstruction method. A projector was used to project a digital fringe patterns on the object, and the fringes intensity images of the reference plane and of the sample object were recorded by a CMOS camera. The phase difference between the plane and object can be calculated from the fringes images, and the surface profile of the object was reconstructed by using the phase differences. The traditional phase shifting method was accomplished by using PZT actuator or precisely controlled motor to adjust the light source or grating and this is one of the limitations for high speed scanning. Compared with the traditional optical setup, we utilized a micro projector to project the digital fringe patterns on the sample. This diminished the phase shifting processing time and the controlled phase differences between the shifted phases become more precise. Besides, the optical path design based on a portable device scanning system was used to minimize the size and reduce the number of the system components. A screwdriver section about 7mm×5mm×5mm has been scanned and its surface profile was successfully restored. The experimental results showed that the measurement area of our system can be smaller than 10mm×10mm, the precision reached to

  16. Characterization of surface complexes in enhanced Raman scattering

    International Nuclear Information System (INIS)

    Roy, D.; Furtak, T.E.

    1984-01-01

    An indicator molecule, para-nitrosodimethylanaline (p-NDMA), has been used to study the chemical nature of surface complexes involving the active site for SERS in the electrochemical environment. We present evidence for positively charged Ag atoms stabilized by coadsorbed Cl - ions as the primary sites which are produced during the oxidation reduction cycle treatment of an Ag electrode. Depending on the relative number of Cl - ions which influence the Ag site the active site demonstrates a greater or lesser electron accepting character toward p-NDMA. This character is influenced by the applied voltage and by the presence of Tl + ions in the bulk of the solution near the surface. As in previously studied systems p-NDMA/Cl - /Ag complexes demonstrate charge transfer excitation which in this case is from the p-NDMA to the Ag site. These results further solidify the importance of complex formation in electrochemical SERS and suggest that caution should be applied when using SERS as a quantitative measure of surface coverage

  17. Self-Organization during Friction in Complex Surface Engineered Tribosystems

    Directory of Open Access Journals (Sweden)

    Ben D. Beake

    2010-02-01

    Full Text Available Self-organization during friction in complex surface engineered tribosystems is investigated. The probability of self-organization in these complex tribosystems is studied on the basis of the theoretical concepts of irreversible thermodynamics. It is shown that a higher number of interrelated processes within the system result in an increased probability of self-organization. The results of this thermodynamic model are confirmed by the investigation of the wear performance of a novel Ti0.2Al0.55Cr0.2Si0.03Y0.02N/Ti0.25Al0.65Cr0.1N (PVD coating with complex nano-multilayered structure under extreme tribological conditions of dry high-speed end milling of hardened H13 tool steel.

  18. Experimental verification on limit load estimation method for pipes with an arbitrary shaped circumferential surface flaw

    International Nuclear Information System (INIS)

    Li, Yinsheng; Hasegawa, Kunio; Miura, Naoki; Hoshino, Katsuaki

    2010-01-01

    When a flaw is detected in stainless steel pipes during in-service inspection, the limit load criterion given in the codes such as JSME Rules on Fitness-for-Service for Nuclear Power Plants or ASME Boiler and Pressure Vessel Code Section XI can be applied to evaluate the integrity of the pipe. However, in these codes, the limit load criterion is only provided for pipes containing a flaw with uniform depth, although many flaws with complicated shape such as stress corrosion cracking have been actually detected in pipes. In order to evaluate the integrity of the flawed pipes for general case, a limit load estimation method has been proposed by authors considering a circumferential surface flaw with arbitrary shape. The plastic collapse bending moment and corresponding stress are obtained by dividing the surface flaw into several segmented sub-flaws. In this paper, the proposed method was verified by comparing with experimental results. Four-point bending experiments were carried out for full scale stainless steel pipes with a symmetrical or non-symmetrical circumferential flaw. Estimated failure bending moments by the proposed method were found to be in good agreement with the experimental results, and the proposed method was confirmed to be effective for evaluating bending failure of pipes with flaw. (author)

  19. A Scalable Approach for Hardware Semiformal Verification

    OpenAIRE

    Grimm, Tomas; Lettnin, Djones; Hübner, Michael

    2018-01-01

    The current verification flow of complex systems uses different engines synergistically: virtual prototyping, formal verification, simulation, emulation and FPGA prototyping. However, none is able to verify a complete architecture. Furthermore, hybrid approaches aiming at complete verification use techniques that lower the overall complexity by increasing the abstraction level. This work focuses on the verification of complex systems at the RT level to handle the hardware peculiarities. Our r...

  20. Assessment of surface solar irradiance derived from real-time modelling techniques and verification with ground-based measurements

    Science.gov (United States)

    Kosmopoulos, Panagiotis G.; Kazadzis, Stelios; Taylor, Michael; Raptis, Panagiotis I.; Keramitsoglou, Iphigenia; Kiranoudis, Chris; Bais, Alkiviadis F.

    2018-02-01

    This study focuses on the assessment of surface solar radiation (SSR) based on operational neural network (NN) and multi-regression function (MRF) modelling techniques that produce instantaneous (in less than 1 min) outputs. Using real-time cloud and aerosol optical properties inputs from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) on board the Meteosat Second Generation (MSG) satellite and the Copernicus Atmosphere Monitoring Service (CAMS), respectively, these models are capable of calculating SSR in high resolution (1 nm, 0.05°, 15 min) that can be used for spectrally integrated irradiance maps, databases and various applications related to energy exploitation. The real-time models are validated against ground-based measurements of the Baseline Surface Radiation Network (BSRN) in a temporal range varying from 15 min to monthly means, while a sensitivity analysis of the cloud and aerosol effects on SSR is performed to ensure reliability under different sky and climatological conditions. The simulated outputs, compared to their common training dataset created by the radiative transfer model (RTM) libRadtran, showed median error values in the range -15 to 15 % for the NN that produces spectral irradiances (NNS), 5-6 % underestimation for the integrated NN and close to zero errors for the MRF technique. The verification against BSRN revealed that the real-time calculation uncertainty ranges from -100 to 40 and -20 to 20 W m-2, for the 15 min and monthly mean global horizontal irradiance (GHI) averages, respectively, while the accuracy of the input parameters, in terms of aerosol and cloud optical thickness (AOD and COT), and their impact on GHI, was of the order of 10 % as compared to the ground-based measurements. The proposed system aims to be utilized through studies and real-time applications which are related to solar energy production planning and use.

  1. New approach to accuracy verification of 3D surface models: An analysis of point cloud coordinates.

    Science.gov (United States)

    Lee, Wan-Sun; Park, Jong-Kyoung; Kim, Ji-Hwan; Kim, Hae-Young; Kim, Woong-Chul; Yu, Chin-Ho

    2016-04-01

    The precision of two types of surface digitization devices, i.e., a contact probe scanner and an optical scanner, and the trueness of two types of stone replicas, i.e., one without an imaging powder (SR/NP) and one with an imaging powder (SR/P), were evaluated using a computer-aided analysis. A master die was fabricated from stainless steel. Ten impressions were taken, and ten stone replicas were prepared from Type IV stone (Fujirock EP, GC, Leuven, Belgium). The precision of two types of scanners was analyzed using the root mean square (RMS), measurement error (ME), and limits of agreement (LoA) at each coordinate. The trueness of the stone replicas was evaluated using the total deviation. A Student's t-test was applied to compare the discrepancies between the CAD-reference-models of the master die (m-CRM) and point clouds for the two types of stone replicas (α=.05). The RMS values for the precision were 1.58, 1.28, and 0.98μm along the x-, y-, and z-axes in the contact probe scanner and 1.97, 1.32, and 1.33μm along the x-, y-, and z-axes in the optical scanner, respectively. A comparison with m-CRM revealed a trueness of 7.10μm for SR/NP and 8.65μm for SR/P. The precision at each coordinate (x-, y-, and z-axes) was revealed to be higher than the one assessed in the previous method (overall offset differences). A comparison between the m-CRM and 3D surface models of the stone replicas revealed a greater dimensional change in SR/P than in SR/NP. Copyright © 2015 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  2. Development of a Novel Bone Conduction Verification Tool Using a Surface Microphone: Validation With Percutaneous Bone Conduction Users.

    Science.gov (United States)

    Hodgetts, William; Scott, Dylan; Maas, Patrick; Westover, Lindsey

    2018-03-23

    . There were 90 planned comparisons of interest, three at each frequency (3 × 10) for the three input levels (30 × 3). Therefore, to minimize a type 1 error associated with multiple comparisons, we adjusted alpha using the Holm-Bonferroni method. There were five comparisons that yielded significant differences between the skull simulator and surface microphone (test and retest) in the estimation of audibility. However, the mean difference in these effects was small at 3.3 dB. Both sensors yielded equivalent results for the majority of comparisons. Models of bone conduction devices that have intact skin cannot be measured with the skull simulator. This study is the first to present and evaluate a new tool for bone conduction verification. The surface microphone is capable of yielding equivalent audibility measurements as the skull simulator for percutaneous bone conduction users at multiple input levels. This device holds potential for measuring other bone conduction devices (Sentio, BoneBridge, Attract, Soft headband devices) that do not have a percutaneous implant.

  3. AATSR land surface temperature product algorithm verification over a WATERMED site

    Science.gov (United States)

    Noyes, E. J.; Sòria, G.; Sobrino, J. A.; Remedios, J. J.; Llewellyn-Jones, D. T.; Corlett, G. K.

    A new operational Land Surface Temperature (LST) product generated from data acquired by the Advanced Along-Track Scanning Radiometer (AATSR) provides the opportunity to measure LST on a global scale with a spatial resolution of 1 km2. The target accuracy of the product, which utilises nadir data from the AATSR thermal channels at 11 and 12 μm, is 2.5 K for daytime retrievals and 1.0 K at night. We present the results of an experiment where the performance of the algorithm has been assessed for one daytime and one night time overpass occurring over the WATERMED field site near Marrakech, Morocco, on 05 March 2003. Top of atmosphere (TOA) brightness temperatures (BTs) are simulated for 12 pixels from each overpass using a radiative transfer model, with the LST product and independent emissivity values and atmospheric data as inputs. We have estimated the error in the LST product over this biome for this set of conditions by applying the operational AATSR LST retrieval algorithm to the modelled BTs and comparing the results with the original AATSR LSTs input into the model. An average bias of -1.00 K (standard deviation 0.07 K) for the daytime data, and -1.74 K (standard deviation 0.02 K) for the night time data is obtained, which indicates that the algorithm is yielding an LST that is too cold under these conditions. While these results are within specification for daytime retrievals, this suggests that the target accuracy of 1.0 K at night is not being met within this biome.

  4. Constraining the Surface Energy Balance of Snow in Complex Terrain

    Science.gov (United States)

    Lapo, Karl E.

    Physically-based snow models form the basis of our understanding of current and future water and energy cycles, especially in mountainous terrain. These models are poorly constrained and widely diverge from each other, demonstrating a poor understanding of the surface energy balance. This research aims to improve our understanding of the surface energy balance in regions of complex terrain by improving our confidence in existing observations and improving our knowledge of remotely sensed irradiances (Chapter 1), critically analyzing the representation of boundary layer physics within land models (Chapter 2), and utilizing relatively novel observations to in the diagnoses of model performance (Chapter 3). This research has improved the understanding of the literal and metaphorical boundary between the atmosphere and land surface. Solar irradiances are difficult to observe in regions of complex terrain, as observations are subject to harsh conditions not found in other environments. Quality control methods were developed to handle these unique conditions. These quality control methods facilitated an analysis of estimated solar irradiances over mountainous environments. Errors in the estimated solar irradiance are caused by misrepresenting the effect of clouds over regions of topography and regularly exceed the range of observational uncertainty (up to 80Wm -2) in all regions examined. Uncertainty in the solar irradiance estimates were especially pronounced when averaging over high-elevation basins, with monthly differences between estimates up to 80Wm-2. These findings can inform the selection of a method for estimating the solar irradiance and suggest several avenues of future research for improving existing methods. Further research probed the relationship between the land surface and atmosphere as it pertains to the stable boundary layers that commonly form over snow-covered surfaces. Stable conditions are difficult to represent, especially for low wind speed

  5. Energetic Surface Smoothing of Complex Metal-Oxide Thin Films

    International Nuclear Information System (INIS)

    Willmott, P.R.; Herger, R.; Schlepuetz, C.M.; Martoccia, D.; Patterson, B.D.

    2006-01-01

    A novel energetic smoothing mechanism in the growth of complex metal-oxide thin films is reported from in situ kinetic studies of pulsed laser deposition of La 1-x Sr x MnO 3 on SrTiO 3 , using x-ray reflectivity. Below 50% monolayer coverage, prompt insertion of energetic impinging species into small-diameter islands causes them to break up to form daughter islands. This smoothing mechanism therefore inhibits the formation of large-diameter 2D islands and the seeding of 3D growth. Above 50% coverage, islands begin to coalesce and their breakup is thereby suppressed. The energy of the incident flux is instead rechanneled into enhanced surface diffusion, which leads to an increase in the effective surface temperature of ΔT≅500 K. These results have important implications on optimal conditions for nanoscale device fabrication using these materials

  6. Nanofluidic structures with complex three-dimensional surfaces

    International Nuclear Information System (INIS)

    Stavis, Samuel M; Gaitan, Michael; Strychalski, Elizabeth A

    2009-01-01

    Nanofluidic devices have typically explored a design space of patterns limited by a single nanoscale structure depth. A method is presented here for fabricating nanofluidic structures with complex three-dimensional (3D) surfaces, utilizing a single layer of grayscale photolithography and standard integrated circuit manufacturing tools. This method is applied to construct nanofluidic devices with numerous (30) structure depths controlled from ∼10 to ∼620 nm with an average standard deviation of 1 cm. A prototype 3D nanofluidic device is demonstrated that implements size exclusion of rigid nanoparticles and variable nanoscale confinement and deformation of biomolecules.

  7. Zinc surface complexes on birnessite: A density functional theory study

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Kideok D.; Refson, Keith; Sposito, Garrison

    2009-01-05

    Biogeochemical cycling of zinc is strongly influenced by sorption on birnessite minerals (layer-type MnO2), which are found in diverse terrestrial and aquatic environments. Zinc has been observed to form both tetrahedral (Zn{sup IV}) and octahedral (Zn{sup VI}) triple-corner-sharing surface complexes (TCS) at Mn(IV) vacancy sites in hexagonal birnessite. The octahedral complex is expected to be similar to that of Zn in the Mn oxide mineral, chalcophanite (ZnMn{sub 3}O{sub 7} {center_dot} 3H{sub 2}O), but the reason for the occurrence of the four-coordinate Zn surface species remains unclear. We address this issue computationally using spin-polarized Density Functional Theory (DFT) to examine the Zn{sub IV}-TCS and Zn{sup VI}-TCS species. Structural parameters obtained by DFT geometry optimization were in excellent agreement with available experimental data on Zn-birnessites. Total energy, magnetic moments, and electron-overlap populations obtained by DFT for isolated Zn{sup IV}-TCS revealed that this species is stable in birnessite without a need for Mn(III) substitution in the octahedral sheet and that it is more effective in reducing undersaturation of surface O at a Mn vacancy than is Zn{sub VI}-TCS. Comparison between geometry-optimized ZnMn{sub 3}O{sub 7} {center_dot} 3H{sub 2}O (chalcophanite) and the hypothetical monohydrate mineral, ZnMn{sub 3}O{sub 7} {center_dot} H{sub 2}O, which contains only tetrahedral Zn, showed that the hydration state of Zn significantly affects birnessite structural stability. Finally, our study also revealed that, relative to their positions in an ideal vacancy-free MnO{sub 2}, Mn nearest to Zn in a TCS surface complex move toward the vacancy by 0.08-0.11 {angstrom}, while surface O bordering the vacancy move away from it by 0.16-0.21 {angstrom}, in agreement with recent X-ray absorption spectroscopic analyses.

  8. Advanced verification topics

    CERN Document Server

    Bhattacharya, Bishnupriya; Hall, Gary; Heaton, Nick; Kashai, Yaron; Khan Neyaz; Kirshenbaum, Zeev; Shneydor, Efrat

    2011-01-01

    The Accellera Universal Verification Methodology (UVM) standard is architected to scale, but verification is growing and in more than just the digital design dimension. It is growing in the SoC dimension to include low-power and mixed-signal and the system integration dimension to include multi-language support and acceleration. These items and others all contribute to the quality of the SOC so the Metric-Driven Verification (MDV) methodology is needed to unify it all into a coherent verification plan. This book is for verification engineers and managers familiar with the UVM and the benefits it brings to digital verification but who also need to tackle specialized tasks. It is also written for the SoC project manager that is tasked with building an efficient worldwide team. While the task continues to become more complex, Advanced Verification Topics describes methodologies outside of the Accellera UVM standard, but that build on it, to provide a way for SoC teams to stay productive and profitable.

  9. Hazardous Materials Verification and Limited Characterization Report on Sodium and Caustic Residuals in Materials and Fuel Complex Facilities MFC-799/799A

    Energy Technology Data Exchange (ETDEWEB)

    Gary Mecham

    2010-08-01

    This report is a companion to the Facilities Condition and Hazard Assessment for Materials and Fuel Complex Sodium Processing Facilities MFC-799/799A and Nuclear Calibration Laboratory MFC-770C (referred to as the Facilities Condition and Hazards Assessment). This report specifically responds to the requirement of Section 9.2, Item 6, of the Facilities Condition and Hazards Assessment to provide an updated assessment and verification of the residual hazardous materials remaining in the Sodium Processing Facilities processing system. The hazardous materials of concern are sodium and sodium hydroxide (caustic). The information supplied in this report supports the end-point objectives identified in the Transition Plan for Multiple Facilities at the Materials and Fuels Complex, Advanced Test Reactor, Central Facilities Area, and Power Burst Facility, as well as the deactivation and decommissioning critical decision milestone 1, as specified in U.S. Department of Energy Guide 413.3-8, “Environmental Management Cleanup Projects.” Using a tailored approach and based on information obtained through a combination of process knowledge, emergency management hazardous assessment documentation, and visual inspection, this report provides sufficient detail regarding the quantity of hazardous materials for the purposes of facility transfer; it also provides that further characterization/verification of these materials is unnecessary.

  10. Uranium(VI) sorption onto magnetite. Increasing confidence in surface complexation models using chemically evident surface chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Bok, Frank [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Surface Processes

    2017-06-01

    Surface complexation models have made great efforts in describing the sorption of various radionuclides on naturally occurring mineral phases. Unfortunately, many of the published sorption parameter sets are built upon unrealistic or even wrong surface chemistry. This work describes the benefit of combining spectroscopic and batch sorption experimental data to create a reliable and consistent surface complexation parameter set.

  11. Reliability of surface EMG measurements from the suprahyoid muscle complex

    DEFF Research Database (Denmark)

    Kothari, Mohit; Stubbs, Peter William; Pedersen, Asger Roer

    2017-01-01

    of using the suprahyoid muscle complex (SMC) using surface electromyography (sEMG) to assess changes to neural pathways by determining the reliability of measurements in healthy participants over days. Methods: Seventeen healthy participants were recruited. Measurements were performed twice with one week...... on stimulus type/intensity) had significantly different MEP values between day 1 and day 2 for single pulse and paired pulse TMS. A large stimulus artefact resulted in MEP responses that could not be assessed in four participants. Conclusions: The assessment of the SMC using sEMG following TMS was poorly...... reliable for ≈50% of participants. Although using sEMG to assess swallowing musculature function is easier to perform clinically and more comfortable to patients than invasive measures, as the measurement of muscle activity using TMS is unreliable, the use of sEMG for this muscle group is not recommended...

  12. Surface Complexation of Neptunium(V) with Goethite

    International Nuclear Information System (INIS)

    Jerden, James L.; Kropf, A. Jeremy

    2007-01-01

    Batch adsorption experiments in which neptunium-bearing solutions were reacted with goethite (alpha-FeOOH) have been performed to study uptake mechanisms in sodium chloride and calcium-bearing sodium silicate solutions. This paper presents results identifying and quantifying the mechanisms by which neptunium is adsorbed as a function of pH and reaction time (aging). Also presented are results from tests in which neptunium is reacted with goethite in the presence of other cations (uranyl and calcium) that may compete with neptunium for sorption sites. The desorption of neptunium from goethite has been studied by re-suspending the neptunium-loaded goethite samples in solutions containing no neptunium. Selected reacted sorbent samples were analyzed by x-ray absorption spectroscopy (XAS) to determine the oxidation state and molecular speciation of the adsorbed neptunium. Results have been used to establish the pH adsorption edge of neptunium on goethite in sodium chloride and calcium-bearing sodium silicate solutions. The results indicate that neptunium uptake on goethite reaches 95% at a pH of approximately 7 and begins to decrease at pH values greater than 8.5. Distribution coefficients for neptunium sorption range from less than 1000 (moles/kg) sorbed / (moles/kg) solution at pH less than 5.0 to greater than 10,000 (moles/kg) sorbed / (moles/kg) solution at pH greater than 7.0. Distribution coefficients as high as 100,000 (moles/kg) sorbed / (moles/kg) solution were recorded for the tests done in calcite equilibrated sodium silicate solutions. XAS results show that neptunium complexes with the goethite surface mainly as Np(V) (although Np(IV) is prevalent in some of the longer-duration sorption tests). The neptunium adsorbed to goethite shows Np-O bond length of approximately 1.8 angstroms which is representative of the Np-O axial bond in the neptunyl(V) complex. This neptunyl(V) ion is coordinated to 5 or 6 equatorial oxygens with Np-O bond lengths of 2

  13. First principles studies of complex oxide surfaces and interfaces

    International Nuclear Information System (INIS)

    Noguera, Claudine; Finocchi, Fabio; Goniakowski, Jacek

    2004-01-01

    Oxides enter our everyday life and exhibit an impressive variety of physical and chemical properties. The understanding of their behaviour, which is often determined by the electronic and atomic structures of their surfaces and interfaces, is a key question in many fields, such as geology, environmental chemistry, catalysis, thermal coatings, microelectronics, and bioengineering. In the last decade, first principles methods, mainly those based on the density functional theory, have been frequently applied to study complex oxide surfaces and interfaces, complementing the experimental observations. In this work, we discuss some of these contributions, with emphasis on several issues that are especially important when dealing with oxides: the local electronic structure at interfaces, and its connection with chemical reactivity; the charge redistribution and the bonding variations, in relation to screening properties; and the possibility of bridging the gap between model and real systems by taking into account the chemical environments and the effect of finite temperatures, and by performing simulations on systems of an adequate (large) size

  14. Multilateral disarmament verification

    International Nuclear Information System (INIS)

    Persbo, A.

    2013-01-01

    Non-governmental organisations, such as VERTIC (Verification Research, Training and Information Centre), can play an important role in the promotion of multilateral verification. Parties involved in negotiating nuclear arms accords are for the most part keen that such agreements include suitable and robust provisions for monitoring and verification. Generally progress in multilateral arms control verification is often painstakingly slow, but from time to time 'windows of opportunity' - that is, moments where ideas, technical feasibility and political interests are aligned at both domestic and international levels - may occur and we have to be ready, so the preparatory work is very important. In the context of nuclear disarmament, verification (whether bilateral or multilateral) entails an array of challenges, hurdles and potential pitfalls relating to national security, health, safety and even non-proliferation, so preparatory work is complex and time-greedy. A UK-Norway Initiative was established in order to investigate the role that a non-nuclear-weapon state such as Norway could potentially play in the field of nuclear arms control verification. (A.C.)

  15. Verification study on technology for preliminary investigation for HLW geological disposal. Part 2. Verification of surface geophysical prospecting through establishing site descriptive models

    International Nuclear Information System (INIS)

    Kondo, Hirofumi; Suzuki, Koichi; Hasegawa, Takuma; Goto, Keiichiro; Yoshimura, Kimitaka; Muramoto, Shigenori

    2012-01-01

    The Yokosuka demonstration and validation project using Yokosuka CRIEPI site has been conducted since FY 2006 as a cooperative research between NUMO (Nuclear Waste Management Organization of Japan) and CRIEPI. The objectives of this project are to examine and to refine the basic methodology of the investigation and assessment of properties of geological environment in the stage of Preliminary Investigation for HLW geological disposal. Within Preliminary Investigation technologies, surface geophysical prospecting is an important means of obtaining information from deep geological environment for planning borehole surveys. In FY 2010, both seismic prospecting (seismic reflection and vertical seismic profiling methods) for obtaining information about geological structure and electromagnetic prospecting (magneto-telluric and time domain electromagnetic methods) for obtaining information about resistivity structure reflecting the distribution of salt water/fresh water boundary to a depth of over several hundred meters were conducted in the Yokosuka CRIEPI site. Through these surveys, the contribution of geophysical prospecting methods in the surface survey stage to improving the reliability of site descriptive models was confirmed. (author)

  16. Adaptive Surface Modeling of Soil Properties in Complex Landforms

    Directory of Open Access Journals (Sweden)

    Wei Liu

    2017-06-01

    Full Text Available Abstract: Spatial discontinuity often causes poor accuracy when a single model is used for the surface modeling of soil properties in complex geomorphic areas. Here we present a method for adaptive surface modeling of combined secondary variables to improve prediction accuracy during the interpolation of soil properties (ASM-SP. Using various secondary variables and multiple base interpolation models, ASM-SP was used to interpolate soil K+ in a typical complex geomorphic area (Qinghai Lake Basin, China. Five methods, including inverse distance weighting (IDW, ordinary kriging (OK, and OK combined with different secondary variables (e.g., OK-Landuse, OK-Geology, and OK-Soil, were used to validate the proposed method. The mean error (ME, mean absolute error (MAE, root mean square error (RMSE, mean relative error (MRE, and accuracy (AC were used as evaluation indicators. Results showed that: (1 The OK interpolation result is spatially smooth and has a weak bull's-eye effect, and the IDW has a stronger ‘bull’s-eye’ effect, relatively. They both have obvious deficiencies in depicting spatial variability of soil K+. (2 The methods incorporating combinations of different secondary variables (e.g., ASM-SP, OK-Landuse, OK-Geology, and OK-Soil were associated with lower estimation bias. Compared with IDW, OK, OK-Landuse, OK-Geology, and OK-Soil, the accuracy of ASM-SP increased by 13.63%, 10.85%, 9.98%, 8.32%, and 7.66%, respectively. Furthermore, ASM-SP was more stable, with lower MEs, MAEs, RMSEs, and MREs. (3 ASM-SP presents more details than others in the abrupt boundary, which can render the result consistent with the true secondary variables. In conclusion, ASM-SP can not only consider the nonlinear relationship between secondary variables and soil properties, but can also adaptively combine the advantages of multiple models, which contributes to making the spatial interpolation of soil K+ more reasonable.

  17. Surface complexation models for uranium adsorption in the sub-surface environment

    International Nuclear Information System (INIS)

    Payne, T.E.

    2007-01-01

    Adsorption experiments with soil component minerals under a range of conditions are being used to develop models of uranium(VI) uptake in the sub-surface environment. The results show that adsorption of U on iron oxides and clay minerals is influenced by chemical factors including the pH, partial pressure of CO 2 , and the presence of ligands such as phosphate. Surface complexation models (SCMs) can be used to simulate U adsorption on these minerals. The SCMs are based on plausible mechanistic assumptions and describe the experimental data more adequately than Kd values or sorption isotherms. It is conceptually possible to simulate U sorption data on complex natural samples by combining SCMs for individual component minerals. This approach was used to develop a SCM for U adsorption to mineral assemblages from Koongarra (Australia), and produced a reasonable description of U uptake. In order to assess the applicability of experimental data to the field situation, in-situ measurements of U distributions between solid and liquid phases were undertaken at the Koongarra U deposit. This field partitioning data showed a satisfactory agreement with laboratory sorption data obtained under comparable conditions. (author)

  18. Procedure generation and verification

    International Nuclear Information System (INIS)

    Sheely, W.F.

    1986-01-01

    The Department of Energy has used Artificial Intelligence of ''AI'' concepts to develop two powerful new computer-based techniques to enhance safety in nuclear applications. The Procedure Generation System, and the Procedure Verification System, can be adapted to other commercial applications, such as a manufacturing plant. The Procedure Generation System can create a procedure to deal with the off-normal condition. The operator can then take correct actions on the system in minimal time. The Verification System evaluates the logic of the Procedure Generator's conclusions. This evaluation uses logic techniques totally independent of the Procedure Generator. The rapid, accurate generation and verification of corrective procedures can greatly reduce the human error, possible in a complex (stressful/high stress) situation

  19. Nuclear disarmament verification

    International Nuclear Information System (INIS)

    DeVolpi, A.

    1993-01-01

    Arms control treaties, unilateral actions, and cooperative activities -- reflecting the defusing of East-West tensions -- are causing nuclear weapons to be disarmed and dismantled worldwide. In order to provide for future reductions and to build confidence in the permanency of this disarmament, verification procedures and technologies would play an important role. This paper outlines arms-control objectives, treaty organization, and actions that could be undertaken. For the purposes of this Workshop on Verification, nuclear disarmament has been divided into five topical subareas: Converting nuclear-weapons production complexes, Eliminating and monitoring nuclear-weapons delivery systems, Disabling and destroying nuclear warheads, Demilitarizing or non-military utilization of special nuclear materials, and Inhibiting nuclear arms in non-nuclear-weapons states. This paper concludes with an overview of potential methods for verification

  20. Uncertainty analysis of point by point sampling complex surfaces using touch probe CMMs

    DEFF Research Database (Denmark)

    Barini, Emanuele; Tosello, Guido; De Chiffre, Leonardo

    2007-01-01

    The paper describes a study concerning point by point scanning of complex surfaces using tactile CMMs. A four factors-two level full factorial experiment was carried out, involving measurements on a complex surface configuration item comprising a sphere, a cylinder and a cone, combined in a singl...

  1. Symplectic geometry on moduli spaces of holomorphic bundles over complex surfaces

    OpenAIRE

    Khesin, Boris; Rosly, Alexei

    2000-01-01

    We give a comparative description of the Poisson structures on the moduli spaces of flat connections on real surfaces and holomorphic Poisson structures on the moduli spaces of holomorphic bundles on complex surfaces. The symplectic leaves of the latter are classified by restrictions of the bundles to certain divisors. This can be regarded as fixing a "complex analogue of the holonomy" of a connection along a "complex analogue of the boundary" in analogy with the real case.

  2. Decontamination technology verification test on scraping surface soil on the highway roadside slopes using unmanned scraping machine

    International Nuclear Information System (INIS)

    Fujinaka, Hiroyuki; Kubota, Mitsuru; Shibuya, Susumu; Kasai, Yoshimitsu

    2013-01-01

    The restore the normal life in the contaminated area, reconstruction of the infrastructure is necessary and early decontamination of roads and roadside slopes of highway are required. Decontamination work of roadside slopes is conducted only by hand working so far, but on the high and steep roadside slopes it is desirable to carry out decontamination work by an unmanned scraping machine to reduce working hours and improve safety. In this verification test, decontamination work of the roadside slope of highway, of which area was 20m W x 15m L and divided into two sections, was implemented by the machine or by hand, and working hours and radiation exposure dose were measured. As the results of the test, working hours and radiation exposure dose by the machine were 49% and 63% respectively compared to those by hand. Based on the results, cost and radiation dose for decontamination work on larger slopes were evaluated. Cost by the machine is estimated to be less than that by hand where the area is over 4,000m 2 . It is confirmed that the decontamination work of roadside slopes by the machine can be done more quickly and safely in comparison with hand working. (author)

  3. A contribution to the electron-beam surface-melting process of metallic materials. Numerical simulation and experimental verification

    International Nuclear Information System (INIS)

    Bruckner, A.

    1996-08-01

    For the optimization of the surface melting process it is necessary to make many different experiments. Therefore, the simulation of the surface melting process becomes a major role for the optimization. Most of the simulations, developed for the laser surface melting process, are not usable for the electron-beam surface melting process, because of the different energy input and the possibility of high frequent movement of the electron-beam. In this thesis, a calculation model for electron-beam surface melting is presented. For this numerical simulation a variable volume source is used, which moves in axial direction with the same velocity as the vapor cavity into the material. With this calculation model also the high frequent movement of the electron-beam may be taken into account. The electron-beam diameter is measured with a method of drilling holes with short electron-beam pulses in thin foils. The diameter of the holes depends on the pulse length and reaches a maximal value, which is used for the diameter of the volume source in the calculation. The crack-formation, seen in many treated surfaces, is examined with the Acoustic-Emission Testing. The possibilities of the electron-beam surface melting process are shown with some experiments for different requirements of the treated surfaces, like increasing the hardness, reducing the porosity of a sintered material and the alloying of tin in an aluminium-silicon surface. (author)

  4. Copper complexation capacity in surface waters of the Venice Lagoon.

    Science.gov (United States)

    Delgadillo-Hinojosa, Francisco; Zirino, Alberto; Nasci, Cristina

    2008-10-01

    Total copper (Cu(T)), copper ion activity (pCu) and the copper complexation capacity (CuCC) were determined in samples of seawater collected in July 2003 from the Venice Lagoon. Cu(T) and CuCC showed considerable spatial variability: Cu(T) ranged from 1.8 to 70.0nM, whereas the CuCC varied from 195 to 573nM. pCu values varied from 11.6 to 12.6 and are consistent with those previously reported in estuarine and coastal areas (10.9-14.1). The range of Cu(T) values compares well with those reported in the past in the lagoon and in the adjacent Adriatic Sea. The highest concentrations of Cu(T) were found in samples collected near the industrial area of Porto Marghera, whereas the lowest were measured near the Chioggia and Malamocco inlets, where an intense tidally-driven renewal of seawater takes place. Although CuCC showed a high degree of spatial variability, the values recorded in the Venice Lagoon are comparable to those reported in other estuarine systems. In addition, CuCC was positively correlated with dissolved organic carbon (DOC), suggesting that organic ligands responsible for Cu complexation are part of the bulk organic matter pool in the lagoon. The CuCC:Cu(T) molar ratio was, on average 55:1, indicating that a large excess of complexation capacity exists in the Venice Lagoon. The high levels of CuCC and the narrow range of pCu indicates the importance of the role played by organic ligands in controlling the free ion Cu concentrations in the lagoon, and as a consequence, regulating its availability and/or toxicity.

  5. Complex Surface Concentration Gradients by Stenciled "Electro Click Chemistry"

    DEFF Research Database (Denmark)

    Hansen, Thomas Steen; Lind, Johan Ulrik; Daugaard, Anders Egede

    2010-01-01

    Complex one- or two-dimensional concentration gradients of alkynated molecules are produced on azidized conducting polymer substrates by stenciled "electro click chemistry". The latter describes the local electrochemical generation of catalytically active Cu(I) required to complete a "click...... reaction" between alkynes and azides at room temperature. A stencil on the counter electrode defines the shape and multiplicity of the gradient(s) on the conducting polymer substrate, while the specific reaction conditions control gradient steepness and the maximum concentration deposited. Biologically...

  6. A Runtime Data Verification Cyberinfrastructure for an Automated Robotic Tram System Measuring Surface Reflectance in the Arctic

    Science.gov (United States)

    Gallegos, I.; Goswami, S.; Tweedie, C. E.; Gamon, J.; Gates, A.

    2008-12-01

    Global change is amongst the greatest challenges facing humanity. Understanding the future state of the Earth System and how humans will need to adapt will require improved environmental observation capacity, more thorough understanding of environmental connectivity and integration of such data in to predictive models. Increasingly, environmental science is becoming data driven as the need for answering bigger picture questions increases - more than ever, researchers are collecting larger data streams through automated means, relying on data from other researchers or agencies, and integrating data from different disciplines. Associated with this advancement in the environmental sciences is the need for improved mechanisms and procedures to verify the integrity of data streams and improve trust in and optimization of data and work flows. A collaborative research effort between the Systems Ecology Lab at the University of Texas at El Paso and the University of Alberta performs ground-based hyperspectral remote sensing studies to investigate the effect of soil moisture on arctic ecosystem structure and function using a robotic cart and tramline infrastructure. This system generates about 60,000 data files during a normal field season and because of this high volume of data, it has become nearly impossible to quality check all spectral data collected using traditional data quality checking approaches. This presentation introduces a prototype run-time Data Quality Specification and Monitoring System (DQSMS) that has been developed in a collaborative effort with the NSF-funded Cyber-ShARE Center of Excellence at the University of Texas at El Paso. Using this software, users can customize data quality requirements and flag problematic data for post collection filtering and correction. The software also supports remote real time verification through wireless connectivity. We welcome input from other researchers and the opportunity to adapt this tool to other remote field

  7. Verification of land-atmosphere coupling in forecast models, reanalyses and land surface models using flux site observations.

    Science.gov (United States)

    Dirmeyer, Paul A; Chen, Liang; Wu, Jiexia; Shin, Chul-Su; Huang, Bohua; Cash, Benjamin A; Bosilovich, Michael G; Mahanama, Sarith; Koster, Randal D; Santanello, Joseph A; Ek, Michael B; Balsamo, Gianpaolo; Dutra, Emanuel; Lawrence, D M

    2018-02-01

    We confront four model systems in three configurations (LSM, LSM+GCM, and reanalysis) with global flux tower observations to validate states, surface fluxes, and coupling indices between land and atmosphere. Models clearly under-represent the feedback of surface fluxes on boundary layer properties (the atmospheric leg of land-atmosphere coupling), and may over-represent the connection between soil moisture and surface fluxes (the terrestrial leg). Models generally under-represent spatial and temporal variability relative to observations, which is at least partially an artifact of the differences in spatial scale between model grid boxes and flux tower footprints. All models bias high in near-surface humidity and downward shortwave radiation, struggle to represent precipitation accurately, and show serious problems in reproducing surface albedos. These errors create challenges for models to partition surface energy properly and errors are traceable through the surface energy and water cycles. The spatial distribution of the amplitude and phase of annual cycles (first harmonic) are generally well reproduced, but the biases in means tend to reflect in these amplitudes. Interannual variability is also a challenge for models to reproduce. Our analysis illuminates targets for coupled land-atmosphere model development, as well as the value of long-term globally-distributed observational monitoring.

  8. A Stabilizing Feedback Between Cloud Radiative Effects and Greenland Surface Melt: Verification From Multi-year Automatic Weather Station Measurements

    Science.gov (United States)

    Zender, C. S.; Wang, W.; van As, D.

    2017-12-01

    Clouds have strong impacts on Greenland's surface melt through the interaction with the dry atmosphere and reflective surfaces. However, their effects are uncertain due to the lack of in situ observations. To better quantify cloud radiative effects (CRE) in Greenland, we analyze and interpret multi-year radiation measurements from 30 automatic weather stations encompassing a broad range of climatological and topographical conditions. During melt season, clouds warm surface over most of Greenland, meaning the longwave greenhouse effect outweighs the shortwave shading effect; on the other hand, the spatial variability of net (longwave and shortwave) CRE is dominated by shortwave CRE and in turn by surface albedo, which controls the potential absorption of solar radiation when clouds are absent. The net warming effect decreases with shortwave CRE from high to low altitudes and from north to south (Fig. 1). The spatial correlation between albedo and net CRE is strong (r=0.93, palbedo determines the net CRE seasonal trend, which decreases from May to July and increases afterwards. On an hourly timescale, we find two distinct radiative states in Greenland (Fig. 2). The clear state is characterized by clear-sky conditions or thin clouds, when albedo and solar zenith angle (SZA) weakly correlates with CRE. The cloudy state is characterized by opaque clouds, when the combination of albedo and SZA strongly correlates with CRE (r=0.85, palbedo and solar zenith angle, explains the majority of the CRE variation in spatial distribution, seasonal trend in the ablation zone, and in hourly variability in the cloudy radiative state. Clouds warm the brighter and colder surfaces of Greenland, enhance snow melt, and tend to lower the albedo. Clouds cool the darker and warmer surfaces, inhibiting snow melt, which increases albedo, and thus stabilizes surface melt. This stabilizing mechanism may also occur over sea ice, helping to forestall surface melt as the Arctic becomes dimmer.

  9. High-level verification

    CERN Document Server

    Lerner, Sorin; Kundu, Sudipta

    2011-01-01

    Given the growing size and heterogeneity of Systems on Chip (SOC), the design process from initial specification to chip fabrication has become increasingly complex. This growing complexity provides incentive for designers to use high-level languages such as C, SystemC, and SystemVerilog for system-level design. While a major goal of these high-level languages is to enable verification at a higher level of abstraction, allowing early exploration of system-level designs, the focus so far for validation purposes has been on traditional testing techniques such as random testing and scenario-based

  10. Verification of surface contamination density standard using clearance automatic laser inspection system for objects from a nuclear power plant

    International Nuclear Information System (INIS)

    Sasaki, Michiya; Ogino, Haruyuki; Ichiji, Takeshi; Hattori, Takatoshi

    2008-01-01

    In the clearance level inspection in Japan, it is necessary to indicate that the activity level of the target object must be less than not only the clearance levels, but also the surface contamination density standards. The classification measurements for these two standards have been performed separately, and the GM survey meters based on beta-ray measurement have mainly been used for surface contamination density measurement so far. Recently the Clearance Automatic Laser Inspection System, named CLALIS, has been developed to estimate the low-level activity concentration. This system consists of 3-dimensional laser scanner for shape measurement and eight large NE102A plastic scintillation detectors for gamma-ray measurement, and it has been clarified that the CLALIS has adequate detection ability for clearance measurement of both metal scraps and concrete debris. In this study, we compared the surface contamination densities for a number of actual contaminated and non-contaminated objects generated inside from the radiation controlled area at the Kashiwazaki-Kariwa nuclear power station by using the CLALIS and the GM survey meter. As a result, since CLALIS could detect the surface contamination as well as the GM survey meter for all measurement targets, it was revealed that CLALIS can rationally achieve clearance level inspection in a single radiation measurement. The practicality of CLALIS in view of the detection limit and processing time was discussed by comparison with the usual radiation monitors for surface contamination measurement. (author)

  11. Verification of the effect of surface preparation on Hot Isostatic Pressing diffusion bonding joints of CLAM steel

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yanyun [University of Science and Technology of China, Hefei, Anhui 230027 (China); Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Li, Chunjing, E-mail: chunjing.li@fds.org.cn [Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Huang, Bo; Liu, Shaojun [Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Huang, Qunying [University of Science and Technology of China, Hefei, Anhui 230027 (China); Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui 230031 (China)

    2014-12-15

    Hot Isostatic Pressing (HIP) diffusion bonding with CLAM steel is the primary candidate fabrication technique for the first wall (FW) of DFLL-TBM. Surface state is one of the key factors for the joints quality. The effect of surface state prepared with grinder and miller on HIP diffusion bonding joints of CLAM steel was investigated. HIP diffusion bonding was performed at 140 MPa and 1373 K within 3 h. The mechanical properties of the joints were investigated with instrumented Charpy V-notch impact tests and the microstructures of the joints were analyzed with scanning electron microscopy (SEM). The results showed that the milled samples with fine surface roughness were more suitable for CLAM steel HIP diffusion bonding.

  12. Influence of surface position along the working range of conoscopic holography sensors on dimensional verification of AISI 316 wire EDM machined surfaces.

    Science.gov (United States)

    Fernández, Pedro; Blanco, David; Rico, Carlos; Valiño, Gonzalo; Mateos, Sabino

    2014-03-06

    Conoscopic holography (CH) is a non-contact interferometric technique used for surface digitization which presents several advantages over other optical techniques such as laser triangulation. Among others, the ability for the reconstruction of high-sloped surfaces stands out, and so does its lower dependence on surface optical properties. Nevertheless, similarly to other optical systems, adjustment of CH sensors requires an adequate selection of configuration parameters for ensuring a high quality surface digitizing. This should be done on a surface located as close as possible to the stand-off distance by tuning frequency (F) and power (P) until the quality indicators Signal-to-Noise Ratio (SNR) and signal envelope (Total) meet proper values. However, not all the points of an actual surface are located at the stand-off distance, but they could be located throughout the whole working range (WR). Thus, the quality of a digitized surface may not be uniform. The present work analyses how the quality of a reconstructed surface is affected by its relative position within the WR under different combinations of the parameters F and P. Experiments have been conducted on AISI 316 wire EDM machined flat surfaces. The number of high-quality points digitized as well as distance measurements between different surfaces throughout the WR allowed for comparing the metrological behaviour of the CH sensor with respect to a touch probe (TP) on a CMM.

  13. Influence of Surface Position along the Working Range of Conoscopic Holography Sensors on Dimensional Verification of AISI 316 Wire EDM Machined Surfaces

    Directory of Open Access Journals (Sweden)

    Pedro Fernández

    2014-03-01

    Full Text Available Conoscopic holography (CH is a non-contact interferometric technique used for surface digitization which presents several advantages over other optical techniques such as laser triangulation. Among others, the ability for the reconstruction of high-sloped surfaces stands out, and so does its lower dependence on surface optical properties. Nevertheless, similarly to other optical systems, adjustment of CH sensors requires an adequate selection of configuration parameters for ensuring a high quality surface digitizing. This should be done on a surface located as close as possible to the stand-off distance by tuning frequency (F and power (P until the quality indicators Signal-to-Noise Ratio (SNR and signal envelope (Total meet proper values. However, not all the points of an actual surface are located at the stand-off distance, but they could be located throughout the whole working range (WR. Thus, the quality of a digitized surface may not be uniform. The present work analyses how the quality of a reconstructed surface is affected by its relative position within the WR under different combinations of the parameters F and P. Experiments have been conducted on AISI 316 wire EDM machined flat surfaces. The number of high-quality points digitized as well as distance measurements between different surfaces throughout the WR allowed for comparing the metrological behaviour of the CH sensor with respect to a touch probe (TP on a CMM.

  14. Surface and permeability properties of membranes from polyelectrolyte complexes and polyelectrolyte surfactant complexes

    Czech Academy of Sciences Publication Activity Database

    Schwarz, H. H.; Lukáš, Jaromír; Richau, K.

    2003-01-01

    Roč. 218, 1-2 (2003), s. 1-9 ISSN 0376-7388 R&D Projects: GA AV ČR KSK4050111 Keywords : polyelectrolyte complex membranes * pervaporation * dehydration of organics Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.081, year: 2003

  15. Technology of magnetic abrasive finishing in machining of difficult-to-machine alloy complex surface

    Directory of Open Access Journals (Sweden)

    Fujian MA

    2016-10-01

    Full Text Available The technology of magnetic abrasive finishing is one of the important finishing technologies. Combining with low-frequency vibration and ultrasonic vibration, it can attain higher precision, quality and efficiency. The characteristics and the related current research of magnetic abrasive finishing, vibration assisted magnetic abrasive finishing and ultrasonic assisted magnetic abrasive finishing are introduced. According to the characteristics of the difficult-to-machine alloy's complex surface, the important problems for further study are presented to realize the finishing of complex surface with the technology of magnetic abrasive finishing, such as increasing the machining efficiency by enhancing the magnetic flux density of machining gap and compounding of magnetic energy and others, establishing of the control function during machining and the process planning method for magnetic abrasive finishing of complex surface under the space geometry restraint of complex surface on magnetic pole, etc.

  16. Chromate Adsorption on Selected Soil Minerals: Surface Complexation Modeling Coupled with Spectroscopic Investigation.

    Czech Academy of Sciences Publication Activity Database

    Veselská, V.; Fajgar, Radek; Číhalová, S.; Bolanz, R.M.; Göttlicher, J.; Steininger, R.; Siddique, J.A.; Komárek, M.

    2016-01-01

    Roč. 318, NOV 15 (2016), s. 433-442 ISSN 0304-3894 Institutional support: RVO:67985858 Keywords : surface complexation modeling * chromate * soil minerals Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 6.065, year: 2016

  17. Formal Verification of Continuous Systems

    DEFF Research Database (Denmark)

    Sloth, Christoffer

    2012-01-01

    and the verification procedures should be algorithmically synthesizable. Autonomous control plays an important role in many safety-critical systems. This implies that a malfunction in the control system can have catastrophic consequences, e.g., in space applications where a design flaw can result in large economic...... losses. Furthermore, a malfunction in the control system of a surgical robot may cause death of patients. The previous examples involve complex systems that are required to operate according to complex specifications. The systems cannot be formally verified by modern verification techniques, due...

  18. Identification of Uranyl Surface Complexes an Ferrihydrite: Advanced EXAFS Data Analysis and CD-MUSIC Modeling

    NARCIS (Netherlands)

    Rossberg, A.; Ulrich, K.U.; Weiss, S.; Tsushima, S.; Hiemstra, T.; Scheinost, A.C.

    2009-01-01

    Previous spectroscopic research suggested that uranium(VI) adsorption to iron oxides is dominated by ternary uranyl-carbonato surface complexes across an unexpectedly wide pH range. Formation of such complexes would have a significant impact on the sorption behavior and mobility of uranium in

  19. Surface complexation of selenite on goethite: MO/DFT geometry and charge distribution

    NARCIS (Netherlands)

    Hiemstra, T.; Rietra, R.P.J.J.; Riemsdijk, van W.H.

    2007-01-01

    The adsorption of selenite on goethite (alpha-FeOOH) has been analyzed with the charge distribution (CD) and the multi-site surface complexation (MUSIC) model being combined with an extended Stem (ES) layer model option. The geometry of a set of different types of hydrated iron-selenite complexes

  20. Uranyl adsorption and surface speciation at the imogolite-water interface: Self-consistent spectroscopic and surface complexation models

    Science.gov (United States)

    Arai, Y.; McBeath, M.; Bargar, J.R.; Joye, J.; Davis, J.A.

    2006-01-01

    Macro- and molecular-scale knowledge of uranyl (U(VI)) partitioning reactions with soil/sediment mineral components is important in predicting U(VI) transport processes in the vadose zone and aquifers. In this study, U(VI) reactivity and surface speciation on a poorly crystalline aluminosilicate mineral, synthetic imogolite, were investigated using batch adsorption experiments, X-ray absorption spectroscopy (XAS), and surface complexation modeling. U(VI) uptake on imogolite surfaces was greatest at pH ???7-8 (I = 0.1 M NaNO3 solution, suspension density = 0.4 g/L [U(VI)]i = 0.01-30 ??M, equilibration with air). Uranyl uptake decreased with increasing sodium nitrate concentration in the range from 0.02 to 0.5 M. XAS analyses show that two U(VI) inner-sphere (bidentate mononuclear coordination on outer-wall aluminol groups) and one outer-sphere surface species are present on the imogolite surface, and the distribution of the surface species is pH dependent. At pH 8.8, bis-carbonato inner-sphere and tris-carbonato outer-sphere surface species are present. At pH 7, bis- and non-carbonato inner-sphere surface species co-exist, and the fraction of bis-carbonato species increases slightly with increasing I (0.1-0.5 M). At pH 5.3, U(VI) non-carbonato bidentate mononuclear surface species predominate (69%). A triple layer surface complexation model was developed with surface species that are consistent with the XAS analyses and macroscopic adsorption data. The proton stoichiometry of surface reactions was determined from both the pH dependence of U(VI) adsorption data in pH regions of surface species predominance and from bond-valence calculations. The bis-carbonato species required a distribution of surface charge between the surface and ?? charge planes in order to be consistent with both the spectroscopic and macroscopic adsorption data. This research indicates that U(VI)-carbonato ternary species on poorly crystalline aluminosilicate mineral surfaces may be important in

  1. Surface complexation of carbonate on goethite: IR spectroscopy, structure & charge distribution

    NARCIS (Netherlands)

    Hiemstra, T.; Rahnemaie, R.; Riemsdijk, van W.H.

    2004-01-01

    The adsorption of carbonate on goethite has been evaluated, focussing on the relation between the structure of the surface complex and corresponding adsorption characteristics, like pH dependency and proton co-adsorption. The surface structure of adsorbed CO3-2 has been assessed with (1) a

  2. Direct observation of surface reconstruction and termination on a complex metal oxide catalyst by electron microscopy

    KAUST Repository

    Zhu, Yihan

    2012-03-19

    On the surface: The surface reconstruction of an MoVTeO complex metal oxide catalyst was observed directly by various electron microscopic techniques and the results explain the puzzling catalytic behavior. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. On Verification Modelling of Embedded Systems

    NARCIS (Netherlands)

    Brinksma, Hendrik; Mader, Angelika H.

    Computer-aided verification of embedded systems hinges on the availability of good verification models of the systems at hand. Such models must be much simpler than full design models or specifications to be of practical value, because of the unavoidable combinatorial complexities in the

  4. Reactive surface organometallic complexes observed using dynamic nuclear polarization surface enhanced NMR spectroscopy

    KAUST Repository

    Pump, Eva; Viger-Gravel, Jasmine; Abou-Hamad, Edy; Samantaray, Manoja; Hamzaoui, Bilel; Gurinov, Andrei; Anjum, Dalaver H.; Gajan, David; Lesage, Anne; Bendjeriou-Sedjerari, Anissa; Emsley, Lyndon; Basset, Jean-Marie

    2016-01-01

    Dynamic Nuclear Polarization Surface Enhanced NMR Spectroscopy (DNP SENS) is an emerging technique that allows access to high-sensitivity NMR spectra from surfaces. However, DNP SENS usually requires the use of radicals as an exogenous source of polarization, which has so far limited applications for organometallic surface species to those that do not react with the radicals. Here we show that reactive surface species can be studied if they are immobilized inside porous materials with suitably small windows, and if bulky nitroxide bi-radicals (here TEKPol) are used as the polarization source and which cannot enter the pores. The method is demonstrated by obtaining significant DNP enhancements from highly reactive complelxes [(equivalent to Si-O-)W(Me)(5)] supported on MCM-41, and effects of pore size (6.0, 3.0 and 2.5 nm) on the performance are discussed.

  5. Reactive surface organometallic complexes observed using dynamic nuclear polarization surface enhanced NMR spectroscopy

    KAUST Repository

    Pump, Eva

    2016-08-15

    Dynamic Nuclear Polarization Surface Enhanced NMR Spectroscopy (DNP SENS) is an emerging technique that allows access to high-sensitivity NMR spectra from surfaces. However, DNP SENS usually requires the use of radicals as an exogenous source of polarization, which has so far limited applications for organometallic surface species to those that do not react with the radicals. Here we show that reactive surface species can be studied if they are immobilized inside porous materials with suitably small windows, and if bulky nitroxide bi-radicals (here TEKPol) are used as the polarization source and which cannot enter the pores. The method is demonstrated by obtaining significant DNP enhancements from highly reactive complelxes [(equivalent to Si-O-)W(Me)(5)] supported on MCM-41, and effects of pore size (6.0, 3.0 and 2.5 nm) on the performance are discussed.

  6. Differential topology of complex surfaces elliptic surfaces with p g=1 smooth classification

    CERN Document Server

    Morgan, John W

    1993-01-01

    This book is about the smooth classification of a certain class of algebraicsurfaces, namely regular elliptic surfaces of geometric genus one, i.e. elliptic surfaces with b1 = 0 and b2+ = 3. The authors give a complete classification of these surfaces up to diffeomorphism. They achieve this result by partially computing one of Donalson's polynomial invariants. The computation is carried out using techniques from algebraic geometry. In these computations both thebasic facts about the Donaldson invariants and the relationship of the moduli space of ASD connections with the moduli space of stable bundles are assumed known. Some familiarity with the basic facts of the theory of moduliof sheaves and bundles on a surface is also assumed. This work gives a good and fairly comprehensive indication of how the methods of algebraic geometry can be used to compute Donaldson invariants.

  7. Cork-resin ablative insulation for complex surfaces and method for applying the same

    Science.gov (United States)

    Walker, H. M.; Sharpe, M. H.; Simpson, W. G. (Inventor)

    1980-01-01

    A method of applying cork-resin ablative insulation material to complex curved surfaces is disclosed. The material is prepared by mixing finely divided cork with a B-stage curable thermosetting resin, forming the resulting mixture into a block, B-stage curing the resin-containing block, and slicing the block into sheets. The B-stage cured sheet is shaped to conform to the surface being insulated, and further curing is then performed. Curing of the resins only to B-stage before shaping enables application of sheet material to complex curved surfaces and avoids limitations and disadvantages presented in handling of fully cured sheet material.

  8. Swarm Verification

    Science.gov (United States)

    Holzmann, Gerard J.; Joshi, Rajeev; Groce, Alex

    2008-01-01

    Reportedly, supercomputer designer Seymour Cray once said that he would sooner use two strong oxen to plow a field than a thousand chickens. Although this is undoubtedly wise when it comes to plowing a field, it is not so clear for other types of tasks. Model checking problems are of the proverbial "search the needle in a haystack" type. Such problems can often be parallelized easily. Alas, none of the usual divide and conquer methods can be used to parallelize the working of a model checker. Given that it has become easier than ever to gain access to large numbers of computers to perform even routine tasks it is becoming more and more attractive to find alternate ways to use these resources to speed up model checking tasks. This paper describes one such method, called swarm verification.

  9. Synthesis in situ of gold nanoparticles by a dialkynyl Fischer carbene complex anchored to glass surfaces

    International Nuclear Information System (INIS)

    Bertolino, María Candelaria; Granados, Alejandro Manuel

    2016-01-01

    Highlights: • Fischer carbene 1-W reacts via cycloaddition without Cu(I) with azide terminal surface. • This reaction on the surface is regioselective to internal triple bond of 1-W. • 1-W bound to glass surface produce AuNps in situ fixed to the surface. • This ability is independent of how 1-W is bonded to the surface. • This hybrid surface can be valuable as SERS substrate or in heterogeneous catalysis. - Abstract: In this work we present a detailed study of classic reactions such as “click reaction” and nucleophilic substitution reaction but on glass solid surface (slides). We used different reactive center of a dialkynylalcoxy Fischer carbene complex of tungsten(0) to be anchored to modified glass surface with amine, to obtain aminocarbene, and azide terminal groups. These cycloaddition reaction showed regioselectivity to internal triple bond of dialkynyl Fischer carbene complex without Cu(I) as catalyst. Anyway the carbene anchored was able to act as a reducing agent to produce in situ very stable gold nanoparticles fixed on surface. We showed the characterization of modified glasses by contact angle measurements and XPS. Synthesized nanoparticles were characterized by SEM, XPS, EDS and UV–vis. The modified glasses showed an important enhancement Raman-SERS. This simple, fast and robust method to create a polifunctional and hybrid surfaces can be valuable in a wide range of applications such as Raman-SERS substrates and other optical fields.

  10. Synthesis in situ of gold nanoparticles by a dialkynyl Fischer carbene complex anchored to glass surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Bertolino, María Candelaria, E-mail: cbertolino@fcq.unc.edu.ar; Granados, Alejandro Manuel, E-mail: ale@fcq.unc.edu.ar

    2016-10-15

    Highlights: • Fischer carbene 1-W reacts via cycloaddition without Cu(I) with azide terminal surface. • This reaction on the surface is regioselective to internal triple bond of 1-W. • 1-W bound to glass surface produce AuNps in situ fixed to the surface. • This ability is independent of how 1-W is bonded to the surface. • This hybrid surface can be valuable as SERS substrate or in heterogeneous catalysis. - Abstract: In this work we present a detailed study of classic reactions such as “click reaction” and nucleophilic substitution reaction but on glass solid surface (slides). We used different reactive center of a dialkynylalcoxy Fischer carbene complex of tungsten(0) to be anchored to modified glass surface with amine, to obtain aminocarbene, and azide terminal groups. These cycloaddition reaction showed regioselectivity to internal triple bond of dialkynyl Fischer carbene complex without Cu(I) as catalyst. Anyway the carbene anchored was able to act as a reducing agent to produce in situ very stable gold nanoparticles fixed on surface. We showed the characterization of modified glasses by contact angle measurements and XPS. Synthesized nanoparticles were characterized by SEM, XPS, EDS and UV–vis. The modified glasses showed an important enhancement Raman-SERS. This simple, fast and robust method to create a polifunctional and hybrid surfaces can be valuable in a wide range of applications such as Raman-SERS substrates and other optical fields.

  11. Design of a Symmetrical Quad-rotor Biplane Tail-Sitter Aircraft without Control Surfaces and Experimental Verification

    Directory of Open Access Journals (Sweden)

    Wang Hongyu

    2018-01-01

    Full Text Available This paper presents the design of a symmetrical quad-rotor biplane tail-sitter VTOL UAV (Vertical Take-off and Landing Unmanned Aerial Vehicle which is composed of four rotors and two symmetrically mounted fixed wings. This aircraft achieves high accuracy in the attitude control and smooth flight mode transition with four rotors rather than the conventional VTOL UAVs using control surfaces. The proposal of angled rotor mounting is adopted to address the issue of insufficient yaw control authority. The layout of symmetrically mounted fixed wings makes the aircraft have capability of rapid bidirectional flight mode transition to improve maneuverability. To validate the performance of the aircraft, simulation and flight experiments are both implemented. These results show that the aircraft has a rapid yaw response under condition of the stable attitude control. In comparative experiment, it is shown that the aircraft is more flexible than other similar configuration of aircrafts. This symmetrical quad-rotor biplane tail-sitter VTOL UAV will have a wide range of potential applications in the military and civilian areas due to its superior performance..

  12. Development and experimental verification of a finite element method for accurate analysis of a surface acoustic wave device

    Science.gov (United States)

    Mohibul Kabir, K. M.; Matthews, Glenn I.; Sabri, Ylias M.; Russo, Salvy P.; Ippolito, Samuel J.; Bhargava, Suresh K.

    2016-03-01

    Accurate analysis of surface acoustic wave (SAW) devices is highly important due to their use in ever-growing applications in electronics, telecommunication and chemical sensing. In this study, a novel approach for analyzing the SAW devices was developed based on a series of two-dimensional finite element method (FEM) simulations, which has been experimentally verified. It was found that the frequency response of the two SAW device structures, each having slightly different bandwidth and center lobe characteristics, can be successfully obtained utilizing the current density of the electrodes via FEM simulations. The two SAW structures were based on XY Lithium Niobate (LiNbO3) substrates and had two and four electrode finger pairs in both of their interdigital transducers, respectively. Later, SAW devices were fabricated in accordance with the simulated models and their measured frequency responses were found to correlate well with the obtained simulations results. The results indicated that better match between calculated and measured frequency response can be obtained when one of the input electrode finger pairs was set at zero volts and all the current density components were taken into account when calculating the frequency response of the simulated SAW device structures.

  13. Automated Verification of Virtualized Infrastructures

    DEFF Research Database (Denmark)

    Bleikertz, Sören; Gross, Thomas; Mödersheim, Sebastian Alexander

    2011-01-01

    Virtualized infrastructures and clouds present new challenges for security analysis and formal verification: they are complex environments that continuously change their shape, and that give rise to non-trivial security goals such as isolation and failure resilience requirements. We present a pla...

  14. Applicability of surface complexation modelling in TVO's studies on sorption of radionuclides

    International Nuclear Information System (INIS)

    Carlsson, T.

    1994-03-01

    The report focuses on the possibility of applying surface complexation theories to the conditions at a potential repository site in Finland and of doing proper experimental work in order to determine necessary constants for the models. The report provides background information on: (1) what type experiments should be carried out in order to produce data for surface complexation modelling of sorption phenomena under potential Finnish repository conditions, and (2) how to design and perform properly such experiments, in order to gather data, develop models or both. The report does not describe in detail how proper surface complexation experiments or modelling should be carried out. The work contains several examples of information that may be valuable in both modelling and experimental work. (51 refs., 6 figs., 4 tabs.)

  15. Runtime Verification Through Forward Chaining

    Directory of Open Access Journals (Sweden)

    Alan Perotti

    2014-12-01

    Full Text Available In this paper we present a novel rule-based approach for Runtime Verification of FLTL properties over finite but expanding traces. Our system exploits Horn clauses in implication form and relies on a forward chaining-based monitoring algorithm. This approach avoids the branching structure and exponential complexity typical of tableaux-based formulations, creating monitors with a single state and a fixed number of rules. This allows for a fast and scalable tool for Runtime Verification: we present the technical details together with a working implementation.

  16. Surface Complexation Modeling in Variable Charge Soils: Charge Characterization by Potentiometric Titration

    Directory of Open Access Journals (Sweden)

    Giuliano Marchi

    2015-10-01

    Full Text Available ABSTRACT Intrinsic equilibrium constants of 17 representative Brazilian Oxisols were estimated from potentiometric titration measuring the adsorption of H+ and OH− on amphoteric surfaces in suspensions of varying ionic strength. Equilibrium constants were fitted to two surface complexation models: diffuse layer and constant capacitance. The former was fitted by calculating total site concentration from curve fitting estimates and pH-extrapolation of the intrinsic equilibrium constants to the PZNPC (hand calculation, considering one and two reactive sites, and by the FITEQL software. The latter was fitted only by FITEQL, with one reactive site. Soil chemical and physical properties were correlated to the intrinsic equilibrium constants. Both surface complexation models satisfactorily fit our experimental data, but for results at low ionic strength, optimization did not converge in FITEQL. Data were incorporated in Visual MINTEQ and they provide a modeling system that can predict protonation-dissociation reactions in the soil surface under changing environmental conditions.

  17. Muscle fatigue and contraction intensity modulates the complexity of surface electromyography.

    Science.gov (United States)

    Cashaback, Joshua G A; Cluff, Tyler; Potvin, Jim R

    2013-02-01

    Nonlinear dynamical techniques offer a powerful approach for the investigation of physiological time series. Multiscale entropy analyses have shown that pathological and aging systems are less complex than healthy systems and this finding has been attributed to degraded physiological control processes. A similar phenomenon may arise during fatiguing muscle contractions where surface electromyography signals undergo temporal and spectral changes that arise from the impaired regulation of muscle force production. Here we examine the affect of fatigue and contraction intensity on the short and long-term complexity of biceps brachii surface electromyography. To investigate, we used an isometric muscle fatigue protocol (parsed into three windows) and three contraction intensities (% of maximal elbow joint moment: 40%, 70% and 100%). We found that fatigue reduced the short-term complexity of biceps brachii activity during the last third of the fatiguing contraction. We also found that the complexity of surface electromyography is dependent on contraction intensity. Our results show that multiscale entropy is sensitive to muscle fatigue and contraction intensity and we argue it is imperative that both factors be considered when evaluating the complexity of surface electromyography signals. Our data contribute to a converging body of evidence showing that multiscale entropy can quantify subtle information content in physiological time series. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Toroidal surface complexes of bacteriophage φ12 are responsible for host-cell attachment

    International Nuclear Information System (INIS)

    Leo-Macias, Alejandra; Katz, Garrett; Wei Hui; Alimova, Alexandra; Katz, A.; Rice, William J.; Diaz-Avalos, Ruben; Hu Guobin; Stokes, David L.; Gottlieb, Paul

    2011-01-01

    Cryo-electron tomography and subtomogram averaging are utilized to determine that the bacteriophage φ12, a member of the Cystoviridae family, contains surface complexes that are toroidal in shape, are composed of six globular domains with six-fold symmetry, and have a discrete density connecting them to the virus membrane-envelope surface. The lack of this kind of spike in a reassortant of φ12 demonstrates that the gene for the hexameric spike is located in φ12's medium length genome segment, likely to the P3 open reading frames which are the proteins involved in viral-host cell attachment. Based on this and on protein mass estimates derived from the obtained averaged structure, it is suggested that each of the globular domains is most likely composed of a total of four copies of P3a and/or P3c proteins. Our findings may have implications in the study of the evolution of the cystovirus species in regard to their host specificity. - Research Highlights: → Subtomogram averaging reveals enhanced detail of a φ12 cystovirus surface protein complex. → The surface protein complex has a toroidal shape and six-fold symmetry. → It is encoded by the medium-size genome segment. → The proteins of the surface complex most likely are one copy of P3a and three copies of P3c.

  19. A method of reconstructing complex stratigraphic surfaces with multitype fault constraints

    Science.gov (United States)

    Deng, Shi-Wu; Jia, Yu; Yao, Xing-Miao; Liu, Zhi-Ning

    2017-06-01

    The construction of complex stratigraphic surfaces is widely employed in many fields, such as petroleum exploration, geological modeling, and geological structure analysis. It also serves as an important foundation for data visualization and visual analysis in these fields. The existing surface construction methods have several deficiencies and face various difficulties, such as the presence of multitype faults and roughness of resulting surfaces. In this paper, a surface modeling method that uses geometric partial differential equations (PDEs) is introduced for the construction of stratigraphic surfaces. It effectively solves the problem of surface roughness caused by the irregularity of stratigraphic data distribution. To cope with the presence of multitype complex faults, a two-way projection algorithm between threedimensional space and a two-dimensional plane is proposed. Using this algorithm, a unified method based on geometric PDEs is developed for dealing with multitype faults. Moreover, the corresponding geometric PDE is derived, and an algorithm based on an evolutionary solution is developed. The algorithm proposed for constructing spatial surfaces with real data verifies its computational efficiency and its ability to handle irregular data distribution. In particular, it can reconstruct faulty surfaces, especially those with overthrust faults.

  20. A coupled mass transfer and surface complexation model for uranium (VI) removal from wastewaters

    International Nuclear Information System (INIS)

    Lenhart, J.; Figueroa, L.A.; Honeyman, B.D.

    1994-01-01

    A remediation technique has been developed for removing uranium (VI) from complex contaminated groundwater using flake chitin as a biosorbent in batch and continuous flow configurations. With this system, U(VI) removal efficiency can be predicted using a model that integrates surface complexation models, mass transport limitations and sorption kinetics. This integration allows the reactor model to predict removal efficiencies for complex groundwaters with variable U(VI) concentrations and other constituents. The system has been validated using laboratory-derived kinetic data in batch and CSTR systems to verify the model predictions of U(VI) uptake from simulated contaminated groundwater

  1. Colour interceptions, thermal stability and surface morphology of polyester metal complexes

    International Nuclear Information System (INIS)

    Zohdy, M.H.

    2005-01-01

    Chelating copolymers via grafting of acrylic acid (AAc) and acrylamide (AAm/AAc) comonomer mixture onto polyester micro fiber fabrics (PETMF) using gamma-radiation technique were prepared. The prepared graft chains (PETMF-g-AAc) and (PETMF-g-PAAc/PAAm) acted as chelating sites for some selected transition metal ions. The prepared graft copolymers and their metal complexes were characterized using thermogravimetric analysis (TGA), colour parameters and surface morphology measurements. The colour interception and strength measurements showed that the metal complexation is homogeneously distributed. The results showed that the thermal stability of PETMF was improved after graft copolymerization and metal complexes. Moreover, the degree of grafting enhanced the thermal stability values of the grafted and complexed copolymers up to 25% of magnitude, on the other hand the activation energy of the grafted-copolymer with acrylic acid increased up to 80%. The SEM observation gives further supports to the homogenous distribution of grafting and metal complexation

  2. Functionalized granular activated carbon and surface complexation with chromates and bi-chromates in wastewater

    International Nuclear Information System (INIS)

    Singha, Somdutta; Sarkar, Ujjaini; Luharuka, Pallavi

    2013-01-01

    Cr(VI) is present in the aqueous medium as chromate (CrO 4 2− ) and bi-chromate (HCrO 4 − ). Functionalized granular activated carbons (FACs) are used as adsorbents in the treatment of wastewaters containing hexavalent chromium. The FACs are prepared by chemical modifications of granular activated carbons (GACs) using functionalizing agents like HNO 3 , HCl and HF. The Brunauer, Emmett and Teller surface areas of FAC-HCl (693.5 m 2 /g), FAC-HNO 3 (648.8 m 2 /g) and FAC-HF (726.2 m 2 /g) are comparable to the GAC (777.7 m 2 /g). But, the adsorption capacity of each of the FAC-HNO 3 , FAC-HCl and FAC-HF is found to be higher than the GAC. The functional groups play an important role in the adsorption process and pH has practically no role in this specific case. The FACs have hydrophilic protonated external surfaces in particular, along with the functional surface sites capable to make complexes with the CrO 4 2− and HCrO 4 − present. Surface complex formation is maximized in the order FAC-HNO 3 > FAC-HF > FAC-HCl, in proportion to the total surface acidity. This is also confirmed by the well-known pseudo second-order kinetic model. Physi-sorption equilibrium isotherms are parameterized by using standard Freundlich and Langmuir models. Langmuir fits better. The formation of surface complexes with the functional groups and hexavalent chromium is also revealed in the images of field emission scanning electron micrograph; energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy analysis after adsorption. The intra-particle diffusion is not the only rate-controlling factor. The Boyd's film diffusion model fits very well with R 2 as high as 98.1% for FAC-HNO 3 . This result demonstrates that the functionalization of the GAC by acid treatments would increase the diffusion rate, predominantly with a boundary layer diffusion effect. - Highlights: ► Physico-chemical adsorption using functionalized activated carbon (FACs) is applied. ► FACs

  3. Computational Redox Potential Predictions: Applications to Inorganic and Organic Aqueous Complexes, and Complexes Adsorbed to Mineral Surfaces

    Directory of Open Access Journals (Sweden)

    Krishnamoorthy Arumugam

    2014-04-01

    Full Text Available Applications of redox processes range over a number of scientific fields. This review article summarizes the theory behind the calculation of redox potentials in solution for species such as organic compounds, inorganic complexes, actinides, battery materials, and mineral surface-bound-species. Different computational approaches to predict and determine redox potentials of electron transitions are discussed along with their respective pros and cons for the prediction of redox potentials. Subsequently, recommendations are made for certain necessary computational settings required for accurate calculation of redox potentials. This article reviews the importance of computational parameters, such as basis sets, density functional theory (DFT functionals, and relativistic approaches and the role that physicochemical processes play on the shift of redox potentials, such as hydration or spin orbit coupling, and will aid in finding suitable combinations of approaches for different chemical and geochemical applications. Identifying cost-effective and credible computational approaches is essential to benchmark redox potential calculations against experiments. Once a good theoretical approach is found to model the chemistry and thermodynamics of the redox and electron transfer process, this knowledge can be incorporated into models of more complex reaction mechanisms that include diffusion in the solute, surface diffusion, and dehydration, to name a few. This knowledge is important to fully understand the nature of redox processes be it a geochemical process that dictates natural redox reactions or one that is being used for the optimization of a chemical process in industry. In addition, it will help identify materials that will be useful to design catalytic redox agents, to come up with materials to be used for batteries and photovoltaic processes, and to identify new and improved remediation strategies in environmental engineering, for example the

  4. Using advanced surface complexation models for modelling soil chemistry under forests: Solling forest, Germany

    International Nuclear Information System (INIS)

    Bonten, Luc T.C.; Groenenberg, Jan E.; Meesenburg, Henning; Vries, Wim de

    2011-01-01

    Various dynamic soil chemistry models have been developed to gain insight into impacts of atmospheric deposition of sulphur, nitrogen and other elements on soil and soil solution chemistry. Sorption parameters for anions and cations are generally calibrated for each site, which hampers extrapolation in space and time. On the other hand, recently developed surface complexation models (SCMs) have been successful in predicting ion sorption for static systems using generic parameter sets. This study reports the inclusion of an assemblage of these SCMs in the dynamic soil chemistry model SMARTml and applies this model to a spruce forest site in Solling Germany. Parameters for SCMs were taken from generic datasets and not calibrated. Nevertheless, modelling results for major elements matched observations well. Further, trace metals were included in the model, also using the existing framework of SCMs. The model predicted sorption for most trace elements well. - Highlights: → Surface complexation models can be well applied in field studies. → Soil chemistry under a forest site is adequately modelled using generic parameters. → The model is easily extended with extra elements within the existing framework. → Surface complexation models can show the linkages between major soil chemistry and trace element behaviour. - Surface complexation models with generic parameters make calibration of sorption superfluous in dynamic modelling of deposition impacts on soil chemistry under nature areas.

  5. Surface Wind Regionalization over Complex Terrain: Evaluation and Analysis of a High-Resolution WRF Simulation

    NARCIS (Netherlands)

    Jiménez, P.A.; González-Rouco, J.F.; García-Bustamante, E.; Navarro, J.; Montávez, J.P.; Vilà-Guerau de Arellano, J.; Dudhia, J.; Muñoz-Roldan, A.

    2010-01-01

    This study analyzes the daily-mean surface wind variability over an area characterized by complex topography through comparing observations and a 2-km-spatial-resolution simulation performed with the Weather Research and Forecasting (WRF) model for the period 1992–2005. The evaluation focuses on the

  6. Using advanced surface complexation models for modelling soil chemistry under forests: Solling forest, Germany

    Energy Technology Data Exchange (ETDEWEB)

    Bonten, Luc T.C., E-mail: luc.bonten@wur.nl [Alterra-Wageningen UR, Soil Science Centre, P.O. Box 47, 6700 AA Wageningen (Netherlands); Groenenberg, Jan E. [Alterra-Wageningen UR, Soil Science Centre, P.O. Box 47, 6700 AA Wageningen (Netherlands); Meesenburg, Henning [Northwest German Forest Research Station, Abt. Umweltkontrolle, Sachgebiet Intensives Umweltmonitoring, Goettingen (Germany); Vries, Wim de [Alterra-Wageningen UR, Soil Science Centre, P.O. Box 47, 6700 AA Wageningen (Netherlands)

    2011-10-15

    Various dynamic soil chemistry models have been developed to gain insight into impacts of atmospheric deposition of sulphur, nitrogen and other elements on soil and soil solution chemistry. Sorption parameters for anions and cations are generally calibrated for each site, which hampers extrapolation in space and time. On the other hand, recently developed surface complexation models (SCMs) have been successful in predicting ion sorption for static systems using generic parameter sets. This study reports the inclusion of an assemblage of these SCMs in the dynamic soil chemistry model SMARTml and applies this model to a spruce forest site in Solling Germany. Parameters for SCMs were taken from generic datasets and not calibrated. Nevertheless, modelling results for major elements matched observations well. Further, trace metals were included in the model, also using the existing framework of SCMs. The model predicted sorption for most trace elements well. - Highlights: > Surface complexation models can be well applied in field studies. > Soil chemistry under a forest site is adequately modelled using generic parameters. > The model is easily extended with extra elements within the existing framework. > Surface complexation models can show the linkages between major soil chemistry and trace element behaviour. - Surface complexation models with generic parameters make calibration of sorption superfluous in dynamic modelling of deposition impacts on soil chemistry under nature areas.

  7. Surface complexation of neptunium (V) onto whole cells and cell componets of Shewanella alga

    Energy Technology Data Exchange (ETDEWEB)

    Reed, Donald Timothy [Los Alamos National Laboratory; Deo, Randhir P [ASU; Rittmann, Bruce E [ASU; Songkasiri, Warinthorn [UNAFFILIATED

    2008-01-01

    We systematically quantified surface complexation of neptunium(V) onto whole cells of Shewanella alga strain BrY and onto cell wall and extracellular polymeric substances (EPS) of S. alga. We first performed acid and base titrations and used the mathematical model FITEQL with constant-capacitance surface-complexation to determine the concentrations and deprotonation constants of specific surface functional groups. Deprotonation constants most likely corresponded to a carboxyl site associated with amino acids (pK{sub a} {approx} 2.4), a carboxyl group not associated with amino acids (pK{sub a} {approx} 5), a phosphoryl site (pK{sub a} {approx} 7.2), and an amine site (pK{sub a} > 10). We then carried out batch sorption experiments with Np(V) and each of the S. alga components at different pHs. Results show that solution pH influenced the speciation of Np(V) and each of the surface functional groups. We used the speciation sub-model of the biogeochemical model CCBATCH to compute the stability constants for Np(V) complexation to each surface functional group. The stability constants were similar for each functional group on S. alga bacterial whole cells, cell walls, and EPS, and they explain the complicated sorption patterns when they are combined with the aqueous-phase speciation of Np(V). For pH < 8, NpO{sub 2}{sup +} was the dominant form of Np(V), and its log K values for the low-pK{sub a} carboxyl, other carboxyl, and phosphoryl groups were 1.75, 1.75, and 2.5 to 3.1, respectively. For pH greater than 8, the key surface ligand was amine >XNH3+, which complexed with NpO{sub 2}(CO{sub 3}){sub 3}{sup 5-}. The log K for NpO{sub 2}(CO{sub 3}){sub 3}{sup 5-} complexed onto the amine groups was 3.1 to 3.6. All of the log K values are similar to those of Np(V) complexes with aqueous carboxyl and N-containing carboxyl ligands. These results point towards the important role of surface complexation in defining key actinide-microbiological interactions in the subsurface.

  8. Comparison of Degrees of Potential-Energy-Surface Anharmonicity for Complexes and Clusters with Hydrogen Bonds

    Science.gov (United States)

    Kozlovskaya, E. N.; Doroshenko, I. Yu.; Pogorelov, V. E.; Vaskivskyi, Ye. V.; Pitsevich, G. A.

    2018-01-01

    Previously calculated multidimensional potential-energy surfaces of the MeOH monomer and dimer, water dimer, malonaldehyde, formic acid dimer, free pyridine-N-oxide/trichloroacetic acid complex, and protonated water dimer were analyzed. The corresponding harmonic potential-energy surfaces near the global minima were constructed for series of clusters and complexes with hydrogen bonds of different strengths based on the behavior of the calculated multidimensional potential-energy surfaces. This enabled the introduction of an obvious anharmonicity parameter for the calculated potential-energy surfaces. The anharmonicity parameter was analyzed as functions of the size of the analyzed area near the energy minimum, the number of points over which energies were compared, and the dimensionality of the solved vibrational problem. Anharmonicity parameters for potential-energy surfaces in complexes with strong, medium, and weak H-bonds were calculated under identical conditions. The obtained anharmonicity parameters were compared with the corresponding diagonal anharmonicity constants for stretching vibrations of the bridging protons and the lengths of the hydrogen bridges.

  9. Analysis the complex interaction among flexible nanoparticles and materials surface in the mechanical polishing process

    Energy Technology Data Exchange (ETDEWEB)

    Han Xuesong, E-mail: hanxuesongphd@yahoo.com.cn [School of Mechanical Engineering, Tianjin University, 300072 (China); Gan, Yong X. [Department of Mechanical, Industrial and Manufacturing Engineering, University of Toledo, OH 43606 (United States)

    2011-02-01

    Mechanical polishing (MP), being the important technique of realizing the surface planarization, has already been widely applied in the area of microelectronic manufacturing and computer manufacturing technology. The surface planarization in the MP is mainly realized by mechanical process which depended on the microdynamic behavior of nanoparticle. The complex multibody interaction among nanoparticles and materials surface is different from interaction in the macroscopic multibody system which makes the traditional classical materials machining theory cannot accurately uncover the mystery of the surface generation in the MP. Large-scale classical molecular dynamic (MD) simulation of interaction among nanoparticles and solid surface has been carried out to investigate the physical essence of surface planarization. The particles with small impact angle can generate more uniform global planarization surface but the materials removal rate is lower. The shear interaction between particle and substrate may induce large friction torque and lead to the rotation of particle. The translation plus rotation makes the nanoparticle behaved like micro-milling tool. The results show that the nanoparticles may aggregrate together and form larger cluster thus deteriorate surface the quality. This MD simulation results illuminate that the f inal planarized surface can only be acquired by synergic behavior of all particles using various means such as cutting, impacting, scratching, indentation and so on.

  10. Oriented coupling of major histocompatibility complex (MHC) to sensor surfaces using light assisted immobilisation technology

    DEFF Research Database (Denmark)

    Snabe, Torben; Røder, Gustav Andreas; Neves-Petersen, Maria Teresa

    2005-01-01

    Controlled and oriented immobilisation of proteins for biosensor purposes is of extreme interest since this provides more efficient sensors with a larger density of active binding sites per area compared to sensors produced by conventional immobilisation. In this paper oriented coupling of a major...... histocompatibility complex (MHC class I) to a sensor surface is presented. The coupling was performed using light assisted immobilisation--a novel immobilisation technology which allows specific opening of particular disulphide bridges in proteins which then is used for covalent bonding to thiol-derivatised surfaces...... via a new disulphide bond. Light assisted immobilisation specifically targets the disulphide bridge in the MHC-I molecule alpha(3)-domain which ensures oriented linking of the complex with the peptide binding site exposed away from the sensor surface. Structural analysis reveals that a similar...

  11. Quantitative evaluation and modeling of two-dimensional neovascular network complexity: the surface fractal dimension

    International Nuclear Information System (INIS)

    Grizzi, Fabio; Russo, Carlo; Colombo, Piergiuseppe; Franceschini, Barbara; Frezza, Eldo E; Cobos, Everardo; Chiriva-Internati, Maurizio

    2005-01-01

    Modeling the complex development and growth of tumor angiogenesis using mathematics and biological data is a burgeoning area of cancer research. Architectural complexity is the main feature of every anatomical system, including organs, tissues, cells and sub-cellular entities. The vascular system is a complex network whose geometrical characteristics cannot be properly defined using the principles of Euclidean geometry, which is only capable of interpreting regular and smooth objects that are almost impossible to find in Nature. However, fractal geometry is a more powerful means of quantifying the spatial complexity of real objects. This paper introduces the surface fractal dimension (D s ) as a numerical index of the two-dimensional (2-D) geometrical complexity of tumor vascular networks, and their behavior during computer-simulated changes in vessel density and distribution. We show that D s significantly depends on the number of vessels and their pattern of distribution. This demonstrates that the quantitative evaluation of the 2-D geometrical complexity of tumor vascular systems can be useful not only to measure its complex architecture, but also to model its development and growth. Studying the fractal properties of neovascularity induces reflections upon the real significance of the complex form of branched anatomical structures, in an attempt to define more appropriate methods of describing them quantitatively. This knowledge can be used to predict the aggressiveness of malignant tumors and design compounds that can halt the process of angiogenesis and influence tumor growth

  12. Software verification for nuclear industry

    International Nuclear Information System (INIS)

    Wilburn, N.P.

    1985-08-01

    Why verification of software products throughout the software life cycle is necessary is considered. Concepts of verification, software verification planning, and some verification methodologies for products generated throughout the software life cycle are then discussed

  13. [DNA complexes, formed on aqueous phase surfaces: new planar polymeric and composite nanostructures].

    Science.gov (United States)

    Antipina, M N; Gaĭnutdinov, R V; Rakhnianskaia, A A; Sergeev-Cherenkov, A N; Tolstikhina, A L; Iurova, T V; Kislov, V V; Khomutov, G B

    2003-01-01

    The formation of DNA complexes with Langmuir monolayers of the cationic lipid octadecylamine (ODA) and the new amphiphilic polycation poly-4-vinylpyridine with 16% of cetylpyridinium groups (PVP-16) on the surface of an aqueous solution of native DNA of low ionic strength was studied. Topographic images of Langmuir-Blodgett films of DNA/ODA and DNA/PVP-16 complexes applied to micaceous substrates were investigated by the method of atomic force microscopy. It was found that films of the amphiphilic polycation have an ordered planar polycrystalline structure. The morphology of planar DNA complexes with the amphiphilic cation substantially depended on the incubation time and the phase state of the monolayer on the surface of the aqueous DNA solution. Complex structures and individual DNA molecules were observed on the surface of the amphiphilic monolayer. Along with quasi-linear individual bound DNA molecules, characteristic extended net-like structures and quasi-circular toroidal condensed conformations of planar DNA complexes were detected. Mono- and multilayer films of DNA/PVP-16 complexes were used as templates and nanoreactors for the synthesis of inorganic nanostructures via the binding of metal cations from the solution and subsequent generation of the inorganic phase. As a result, ultrathin polymeric composite films with integrated DNA building blocks and quasi-linear arrays of inorganic semiconductor (CdS) and iron oxide nanoparticles and nanowires were obtained. The nanostructures obtained were characterized by scanning probe microscopy and transmission electron microscopy techniques. The methods developed are promising for investigating the mechanisms of structural organization and transformation in DNA and polyelectrolyte complexes at the gas-liquid interface and for the design of new extremely thin highly ordered planar polymeric and composite materials, films, and coatings with controlled ultrastructure for applications in nanoelectronics and

  14. Surface-illuminant ambiguity and color constancy: effects of scene complexity and depth cues.

    Science.gov (United States)

    Kraft, James M; Maloney, Shannon I; Brainard, David H

    2002-01-01

    Two experiments were conducted to study how scene complexity and cues to depth affect human color constancy. Specifically, two levels of scene complexity were compared. The low-complexity scene contained two walls with the same surface reflectance and a test patch which provided no information about the illuminant. In addition to the surfaces visible in the low-complexity scene, the high-complexity scene contained two rectangular solid objects and 24 paper samples with diverse surface reflectances. Observers viewed illuminated objects in an experimental chamber and adjusted the test patch until it appeared achromatic. Achromatic settings made tinder two different illuminants were used to compute an index that quantified the degree of constancy. Two experiments were conducted: one in which observers viewed the stimuli directly, and one in which they viewed the scenes through an optical system that reduced cues to depth. In each experiment, constancy was assessed for two conditions. In the valid-cue condition, many cues provided valid information about the illuminant change. In the invalid-cue condition, some image cues provided invalid information. Four broad conclusions are drawn from the data: (a) constancy is generally better in the valid-cue condition than in the invalid-cue condition: (b) for the stimulus configuration used, increasing image complexity has little effect in the valid-cue condition but leads to increased constancy in the invalid-cue condition; (c) for the stimulus configuration used, reducing cues to depth has little effect for either constancy condition: and (d) there is moderate individual variation in the degree of constancy exhibited, particularly in the degree to which the complexity manipulation affects performance.

  15. A hybrid 3D SEM reconstruction method optimized for complex geologic material surfaces.

    Science.gov (United States)

    Yan, Shang; Adegbule, Aderonke; Kibbey, Tohren C G

    2017-08-01

    Reconstruction methods are widely used to extract three-dimensional information from scanning electron microscope (SEM) images. This paper presents a new hybrid reconstruction method that combines stereoscopic reconstruction with shape-from-shading calculations to generate highly-detailed elevation maps from SEM image pairs. The method makes use of an imaged glass sphere to determine the quantitative relationship between observed intensity and angles between the beam and surface normal, and the detector and surface normal. Two specific equations are derived to make use of image intensity information in creating the final elevation map. The equations are used together, one making use of intensities in the two images, the other making use of intensities within a single image. The method is specifically designed for SEM images captured with a single secondary electron detector, and is optimized to capture maximum detail from complex natural surfaces. The method is illustrated with a complex structured abrasive material, and a rough natural sand grain. Results show that the method is capable of capturing details such as angular surface features, varying surface roughness, and surface striations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Reactive solute transport in streams: A surface complexation approach for trace metal sorption

    Science.gov (United States)

    Runkel, Robert L.; Kimball, Briant A.; McKnight, Diane M.; Bencala, Kenneth E.

    1999-01-01

    A model for trace metals that considers in-stream transport, metal oxide precipitation-dissolution, and pH-dependent sorption is presented. Linkage between a surface complexation submodel and the stream transport equations provides a framework for modeling sorption onto static and/or dynamic surfaces. A static surface (e.g., an iron- oxide-coated streambed) is defined as a surface with a temporally constant solid concentration. Limited contact between solutes in the water column and the static surface is considered using a pseudokinetic approach. A dynamic surface (e.g., freshly precipitated metal oxides) has a temporally variable solid concentration and is in equilibrium with the water column. Transport and deposition of solute mass sorbed to the dynamic surface is represented in the stream transport equations that include precipitate settling. The model is applied to a pH-modification experiment in an acid mine drainage stream. Dissolved copper concentrations were depressed for a 3 hour period in response to the experimentally elevated pH. After passage of the pH front, copper was desorbed, and dissolved concentrations returned to ambient levels. Copper sorption is modeled by considering sorption to aged hydrous ferric oxide (HFO) on the streambed (static surface) and freshly precipitated HFO in the water column (dynamic surface). Comparison of parameter estimates with reported values suggests that naturally formed iron oxides may be more effective in removing trace metals than synthetic oxides used in laboratory studies. The model's ability to simulate pH, metal oxide precipitation-dissolution, and pH-dependent sorption provides a means of evaluating the complex interactions between trace metal chemistry and hydrologic transport at the field scale.

  17. Verification and disarmament

    Energy Technology Data Exchange (ETDEWEB)

    Blix, H. [IAEA, Vienna (Austria)

    1998-07-01

    The main features are described of the IAEA safeguards verification system that non-nuclear weapon states parties of the NPT are obliged to accept. Verification activities/problems in Iraq and North Korea are discussed.

  18. Verification and disarmament

    International Nuclear Information System (INIS)

    Blix, H.

    1998-01-01

    The main features are described of the IAEA safeguards verification system that non-nuclear weapon states parties of the NPT are obliged to accept. Verification activities/problems in Iraq and North Korea are discussed

  19. Use of polyamfolit complexes of ethyl-amino-crotonate/acrylic acid with surface-active materials for radionuclide extraction

    International Nuclear Information System (INIS)

    Kabdyrakova, A.M.; Artem'ev, O.I.; Protskij, A.V.; Bimendina, L.A.; Yashkarova, M.G.; Orazzhanova, L.K.

    2005-01-01

    Pentifylline of betaine structure was synthesised on the basis of 3-aminocrotonate and acrylic acid. Polyamfolit composition and its complexes with anionic surface-active material (lauryl sulfate of sodium) were determined. It is revealed that complex formation occurs with [polyamfolit]:[surface active material]=1:1 ratio and is accompanied by significant reduce of system characteristics viscosity. The paper presents results of [polyamfolit]:[surface active material] complex apply experimental investigation for radionuclide directed migration in soil. (author)

  20. Mixed DNA/Oligo(ethylene glycol) Functionalized Gold Surface Improve DNA Hybridization in Complex Media

    International Nuclear Information System (INIS)

    Lee, C.; Gamble, L.; Grainger, D.; Castner, D.

    2006-01-01

    Reliable, direct 'sample-to-answer' capture of nucleic acid targets from complex media would greatly improve existing capabilities of DNA microarrays and biosensors. This goal has proven elusive for many current nucleic acid detection technologies attempting to produce assay results directly from complex real-world samples, including food, tissue, and environmental materials. In this study, we have investigated mixed self-assembled thiolated single-strand DNA (ssDNA) monolayers containing a short thiolated oligo(ethylene glycol) (OEG) surface diluent on gold surfaces to improve the specific capture of DNA targets from complex media. Both surface composition and orientation of these mixed DNA monolayers were characterized with x-ray photoelectron spectroscopy (XPS) and near-edge x-ray absorption fine structure (NEXAFS). XPS results from sequentially adsorbed ssDNA/OEG monolayers on gold indicate that thiolated OEG diluent molecules first incorporate into the thiolated ssDNA monolayer and, upon longer OEG exposures, competitively displace adsorbed ssDNA molecules from the gold surface. NEXAFS polarization dependence results (followed by monitoring the N 1s→π* transition) indicate that adsorbed thiolated ssDNA nucleotide base-ring structures in the mixed ssDNA monolayers are oriented more parallel to the gold surface compared to DNA bases in pure ssDNA monolayers. This supports ssDNA oligomer reorientation towards a more upright position upon OEG mixed adlayer incorporation. DNA target hybridization on mixed ssDNA probe/OEG monolayers was monitored by surface plasmon resonance (SPR). Improvements in specific target capture for these ssDNA probe surfaces due to incorporation of the OEG diluent were demonstrated using two model biosensing assays, DNA target capture from complete bovine serum and from salmon genomic DNA mixtures. SPR results demonstrate that OEG incorporation into the ssDNA adlayer improves surface resistance to both nonspecific DNA and protein

  1. Design Process Control for Improved Surface Finish of Metal Additive Manufactured Parts of Complex Build Geometry

    Directory of Open Access Journals (Sweden)

    Mikdam Jamal

    2017-12-01

    Full Text Available Metal additive manufacturing (AM is increasingly used to create complex 3D components at near net shape. However, the surface finish (SF of the metal AM part is uneven, with surface roughness being variable over the facets of the design. Standard post-processing methods such as grinding and linishing often meet with major challenges in finishing parts of complex shape. This paper reports on research that demonstrated that mass finishing (MF processes are able to deliver high-quality surface finishes (Ra and Sa on AM-generated parts of a relatively complex geometry (both internal features and external facets under select conditions. Four processes were studied in this work: stream finishing, high-energy (HE centrifuge, drag finishing and disc finishing. Optimisation of the drag finishing process was then studied using a structured design of experiments (DOE. The effects of a range of finishing parameters were evaluated and optimal parameters and conditions were determined. The study established that the proposed method can be successfully applied in drag finishing to optimise the surface roughness in an industrial application and that it is an economical way of obtaining the maximum amount of information in a short period of time with a small number of tests. The study has also provided an important step in helping understand the requirements of MF to deliver AM-generated parts to a target quality finish and cycle time.

  2. Chromate adsorption on selected soil minerals: Surface complexation modeling coupled with spectroscopic investigation

    Energy Technology Data Exchange (ETDEWEB)

    Veselská, Veronika, E-mail: veselskav@fzp.czu.cz [Department of Environmental Geosciences, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcka 129, CZ-16521, Prague (Czech Republic); Fajgar, Radek [Department of Analytical and Material Chemistry, Institute of Chemical Process Fundamentals of the CAS, v.v.i., Rozvojová 135/1, CZ-16502, Prague (Czech Republic); Číhalová, Sylva [Department of Environmental Geosciences, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcka 129, CZ-16521, Prague (Czech Republic); Bolanz, Ralph M. [Institute of Geosciences, Friedrich-Schiller-University Jena, Carl-Zeiss-Promenade 10, DE-07745, Jena (Germany); Göttlicher, Jörg; Steininger, Ralph [ANKA Synchrotron Radiation Facility, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, DE-76344, Eggenstein-Leopoldshafen (Germany); Siddique, Jamal A.; Komárek, Michael [Department of Environmental Geosciences, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcka 129, CZ-16521, Prague (Czech Republic)

    2016-11-15

    Highlights: • Study of Cr(VI) adsorption on soil minerals over a large range of conditions. • Combined surface complexation modeling and spectroscopic techniques. • Diffuse-layer and triple-layer models used to obtain fits to experimental data. • Speciation of Cr(VI) and Cr(III) was assessed. - Abstract: This study investigates the mechanisms of Cr(VI) adsorption on natural clay (illite and kaolinite) and synthetic (birnessite and ferrihydrite) minerals, including its speciation changes, and combining quantitative thermodynamically based mechanistic surface complexation models (SCMs) with spectroscopic measurements. Series of adsorption experiments have been performed at different pH values (3–10), ionic strengths (0.001–0.1 M KNO{sub 3}), sorbate concentrations (10{sup −4}, 10{sup −5}, and 10{sup −6} M Cr(VI)), and sorbate/sorbent ratios (50–500). Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy were used to determine the surface complexes, including surface reactions. Adsorption of Cr(VI) is strongly ionic strength dependent. For ferrihydrite at pH <7, a simple diffuse-layer model provides a reasonable prediction of adsorption. For birnessite, bidentate inner-sphere complexes of chromate and dichromate resulted in a better diffuse-layer model fit. For kaolinite, outer-sphere complexation prevails mainly at lower Cr(VI) loadings. Dissolution of solid phases needs to be considered for better SCMs fits. The coupled SCM and spectroscopic approach is thus useful for investigating individual minerals responsible for Cr(VI) retention in soils, and improving the handling and remediation processes.

  3. Incorporating classic adsorption isotherms into modern surface complexation models: implications for sorption of radionuclides

    International Nuclear Information System (INIS)

    Kulik, D.A.

    2005-01-01

    Full text of publication follows: Computer-aided surface complexation models (SCM) tend to replace the classic adsorption isotherm (AI) analysis in describing mineral-water interface reactions such as radionuclide sorption onto (hydr) oxides and clays. Any site-binding SCM based on the mole balance of surface sites, in fact, reproduces the (competitive) Langmuir isotherm, optionally amended with electrostatic Coulomb's non-ideal term. In most SCM implementations, it is difficult to incorporate real-surface phenomena (site heterogeneity, lateral interactions, surface condensation) described in classic AI approaches other than Langmuir's. Thermodynamic relations between SCMs and AIs that remained obscure in the past have been recently clarified using new definitions of standard and reference states of surface species [1,2]. On this basis, a method for separating the Langmuir AI into ideal (linear) and non-ideal parts [2] was applied to multi-dentate Langmuir, Frumkin, and BET isotherms. The aim of this work was to obtain the surface activity coefficient terms that make the SCM site mole balance constraints obsolete and, in this way, extend thermodynamic SCMs to cover sorption phenomena described by the respective AIs. The multi-dentate Langmuir term accounts for the site saturation with n-dentate surface species, as illustrated on modeling bi-dentate U VI complexes on goethite or SiO 2 surfaces. The Frumkin term corrects for the lateral interactions of the mono-dentate surface species; in particular, it has the same form as the Coulombic term of the constant-capacitance EDL combined with the Langmuir term. The BET term (three parameters) accounts for more than a monolayer adsorption up to the surface condensation; it can potentially describe the surface precipitation of nickel and other cations on hydroxides and clay minerals. All three non-ideal terms (in GEM SCMs implementation [1,2]) by now are used for non-competing surface species only. Upon 'surface dilution

  4. Native Liquid Extraction Surface Analysis Mass Spectrometry: Analysis of Noncovalent Protein Complexes Directly from Dried Substrates

    Science.gov (United States)

    Martin, Nicholas J.; Griffiths, Rian L.; Edwards, Rebecca L.; Cooper, Helen J.

    2015-08-01

    Liquid extraction surface analysis (LESA) mass spectrometry is a promising tool for the analysis of intact proteins from biological substrates. Here, we demonstrate native LESA mass spectrometry of noncovalent protein complexes of myoglobin and hemoglobin from a range of surfaces. Holomyoglobin, in which apomyoglobin is noncovalently bound to the prosthetic heme group, was observed following LESA mass spectrometry of myoglobin dried onto glass and polyvinylidene fluoride surfaces. Tetrameric hemoglobin [(αβ)2 4H] was observed following LESA mass spectrometry of hemoglobin dried onto glass and polyvinylidene fluoride (PVDF) surfaces, and from dried blood spots (DBS) on filter paper. Heme-bound dimers and monomers were also observed. The `contact' LESA approach was particularly suitable for the analysis of hemoglobin tetramers from DBS.

  5. Surface complexation modeling of Cu(II adsorption on mixtures of hydrous ferric oxide and kaolinite

    Directory of Open Access Journals (Sweden)

    Schaller Melinda S

    2008-09-01

    Full Text Available Abstract Background The application of surface complexation models (SCMs to natural sediments and soils is hindered by a lack of consistent models and data for large suites of metals and minerals of interest. Furthermore, the surface complexation approach has mostly been developed and tested for single solid systems. Few studies have extended the SCM approach to systems containing multiple solids. Results Cu adsorption was measured on pure hydrous ferric oxide (HFO, pure kaolinite (from two sources and in systems containing mixtures of HFO and kaolinite over a wide range of pH, ionic strength, sorbate/sorbent ratios and, for the mixed solid systems, using a range of kaolinite/HFO ratios. Cu adsorption data measured for the HFO and kaolinite systems was used to derive diffuse layer surface complexation models (DLMs describing Cu adsorption. Cu adsorption on HFO is reasonably well described using a 1-site or 2-site DLM. Adsorption of Cu on kaolinite could be described using a simple 1-site DLM with formation of a monodentate Cu complex on a variable charge surface site. However, for consistency with models derived for weaker sorbing cations, a 2-site DLM with a variable charge and a permanent charge site was also developed. Conclusion Component additivity predictions of speciation in mixed mineral systems based on DLM parameters derived for the pure mineral systems were in good agreement with measured data. Discrepancies between the model predictions and measured data were similar to those observed for the calibrated pure mineral systems. The results suggest that quantifying specific interactions between HFO and kaolinite in speciation models may not be necessary. However, before the component additivity approach can be applied to natural sediments and soils, the effects of aging must be further studied and methods must be developed to estimate reactive surface areas of solid constituents in natural samples.

  6. Constructing irregular surfaces to enclose macromolecular complexes for mesoscale modeling using the discrete surface charge optimization (DISCO) algorithm.

    Science.gov (United States)

    Zhang, Qing; Beard, Daniel A; Schlick, Tamar

    2003-12-01

    Salt-mediated electrostatics interactions play an essential role in biomolecular structures and dynamics. Because macromolecular systems modeled at atomic resolution contain thousands of solute atoms, the electrostatic computations constitute an expensive part of the force and energy calculations. Implicit solvent models are one way to simplify the model and associated calculations, but they are generally used in combination with standard atomic models for the solute. To approximate electrostatics interactions in models on the polymer level (e.g., supercoiled DNA) that are simulated over long times (e.g., milliseconds) using Brownian dynamics, Beard and Schlick have developed the DiSCO (Discrete Surface Charge Optimization) algorithm. DiSCO represents a macromolecular complex by a few hundred discrete charges on a surface enclosing the system modeled by the Debye-Hückel (screened Coulombic) approximation to the Poisson-Boltzmann equation, and treats the salt solution as continuum solvation. DiSCO can represent the nucleosome core particle (>12,000 atoms), for example, by 353 discrete surface charges distributed on the surfaces of a large disk for the nucleosome core particle and a slender cylinder for the histone tail; the charges are optimized with respect to the Poisson-Boltzmann solution for the electric field, yielding a approximately 5.5% residual. Because regular surfaces enclosing macromolecules are not sufficiently general and may be suboptimal for certain systems, we develop a general method to construct irregular models tailored to the geometry of macromolecules. We also compare charge optimization based on both the electric field and electrostatic potential refinement. Results indicate that irregular surfaces can lead to a more accurate approximation (lower residuals), and the refinement in terms of the electric field is more robust. We also show that surface smoothing for irregular models is important, that the charge optimization (by the TNPACK

  7. Surface Structures Formed by a Copper(II Complex of Alkyl-Derivatized Indigo

    Directory of Open Access Journals (Sweden)

    Akinori Honda

    2016-10-01

    Full Text Available Assembled structures of dyes have great influence on their coloring function. For example, metal ions added in the dyeing process are known to prevent fading of color. Thus, we have investigated the influence of an addition of copper(II ion on the surface structure of alkyl-derivatized indigo. Scanning tunneling microscope (STM analysis revealed that the copper(II complexes of indigo formed orderly lamellar structures on a HOPG substrate. These lamellar structures of the complexes are found to be more stable than those of alkyl-derivatized indigos alone. Furthermore, 2D chirality was observed.

  8. Riemann surfaces of complex classical trajectories and tunnelling splitting in one-dimensional systems

    Science.gov (United States)

    Harada, Hiromitsu; Mouchet, Amaury; Shudo, Akira

    2017-10-01

    The topology of complex classical paths is investigated to discuss quantum tunnelling splittings in one-dimensional systems. Here the Hamiltonian is assumed to be given as polynomial functions, so the fundamental group for the Riemann surface provides complete information on the topology of complex paths, which allows us to enumerate all the possible candidates contributing to the semiclassical sum formula for tunnelling splittings. This naturally leads to action relations among classically disjoined regions, revealing entirely non-local nature in the quantization condition. The importance of the proper treatment of Stokes phenomena is also discussed in Hamiltonians in the normal form.

  9. Surface complexation modeling calculation of Pb(II) adsorption onto the calcined diatomite

    Science.gov (United States)

    Ma, Shu-Cui; Zhang, Ji-Lin; Sun, De-Hui; Liu, Gui-Xia

    2015-12-01

    Removal of noxious heavy metal ions (e.g. Pb(II)) by surface adsorption of minerals (e.g. diatomite) is an important means in the environmental aqueous pollution control. Thus, it is very essential to understand the surface adsorptive behavior and mechanism. In this work, the Pb(II) apparent surface complexation reaction equilibrium constants on the calcined diatomite and distributions of Pb(II) surface species were investigated through modeling calculations of Pb(II) based on diffuse double layer model (DLM) with three amphoteric sites. Batch experiments were used to study the adsorption of Pb(II) onto the calcined diatomite as a function of pH (3.0-7.0) and different ionic strengths (0.05 and 0.1 mol L-1 NaCl) under ambient atmosphere. Adsorption of Pb(II) can be well described by Freundlich isotherm models. The apparent surface complexation equilibrium constants (log K) were obtained by fitting the batch experimental data using the PEST 13.0 together with PHREEQC 3.1.2 codes and there is good agreement between measured and predicted data. Distribution of Pb(II) surface species on the diatomite calculated by PHREEQC 3.1.2 program indicates that the impurity cations (e.g. Al3+, Fe3+, etc.) in the diatomite play a leading role in the Pb(II) adsorption and dominant formation of complexes and additional electrostatic interaction are the main adsorption mechanism of Pb(II) on the diatomite under weak acidic conditions.

  10. Evaluating polymer degradation with complex mixtures using a simplified surface area method.

    Science.gov (United States)

    Steele, Kandace M; Pelham, Todd; Phalen, Robert N

    2017-09-01

    Chemical-resistant gloves, designed to protect workers from chemical hazards, are made from a variety of polymer materials such as plastic, rubber, and synthetic rubber. One material does not provide protection against all chemicals, thus proper polymer selection is critical. Standardized testing, such as chemical degradation tests, are used to aid in the selection process. The current methods of degradation ratings based on changes in weight or tensile properties can be expensive and data often do not exist for complex chemical mixtures. There are hundreds of thousands of chemical products on the market that do not have chemical resistance data for polymer selection. The method described in this study provides an inexpensive alternative to gravimetric analysis. This method uses surface area change to evaluate degradation of a polymer material. Degradation tests for 5 polymer types against 50 complex mixtures were conducted using both gravimetric and surface area methods. The percent change data were compared between the two methods. The resulting regression line was y = 0.48x + 0.019, in units of percent, and the Pearson correlation coefficient was r = 0.9537 (p ≤ 0.05), which indicated a strong correlation between percent weight change and percent surface area change. On average, the percent change for surface area was about half that of the weight change. Using this information, an equivalent rating system was developed for determining the chemical degradation of polymer gloves using surface area.

  11. Tailored optical vector fields for ultrashort-pulse laser induced complex surface plasmon structuring.

    Science.gov (United States)

    Ouyang, J; Perrie, W; Allegre, O J; Heil, T; Jin, Y; Fearon, E; Eckford, D; Edwardson, S P; Dearden, G

    2015-05-18

    Precise tailoring of optical vector beams is demonstrated, shaping their focal electric fields and used to create complex laser micro-patterning on a metal surface. A Spatial Light Modulator (SLM) and a micro-structured S-waveplate were integrated with a picosecond laser system and employed to structure the vector fields into radial and azimuthal polarizations with and without a vortex phase wavefront as well as superposition states. Imprinting Laser Induced Periodic Surface Structures (LIPSS) elucidates the detailed vector fields around the focal region. In addition to clear azimuthal and radial plasmon surface structures, unique, variable logarithmic spiral micro-structures with a pitch Λ ∼1μm, not observed previously, were imprinted on the surface, confirming unambiguously the complex 2D focal electric fields. We show clearly also how the Orbital Angular Momentum(OAM) associated with a helical wavefront induces rotation of vector fields along the optic axis of a focusing lens and confirmed by the observed surface micro-structures.

  12. Spectroscopic identification of binary and ternary surface complexes of Np(V) on gibbsite.

    Science.gov (United States)

    Gückel, Katharina; Rossberg, André; Müller, Katharina; Brendler, Vinzenz; Bernhard, Gert; Foerstendorf, Harald

    2013-12-17

    For the first time, detailed molecular information on the Np(V) sorption species on amorphous Al(OH)3 and crystalline gibbsite was obtained by in situ time-resolved Attenuated Total Reflection Fourier-Transform Infrared (ATR FT-IR) and Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy. The results consistently demonstrate the formation of mononuclear inner sphere complexes of the NpO2(+) ion irrespective of the prevailing atmospheric condition. The impact of the presence of atmospheric equivalent added carbonate on the speciation in solution and on the surfaces becomes evident from vibrational data. While the 1:1 aqueous carbonato species (NpO2CO3(-)) was found to become predominant in the circumneutral pH range, it is most likely that this species is sorbed onto the gibbsite surface as a ternary inner sphere surface complex where the NpO2(+) moiety is directly coordinated to the functional groups of the gibbsite's surface. These findings are corroborated by results obtained from EXAFS spectroscopy providing further evidence for a bidentate coordination of the Np(V) ion on amorphous Al(OH)3. The identification of the Np(V) surface species on gibbsite constitutes a basic finding for a comprehensive description of the dissemination of neptunium in groundwater systems.

  13. Modeling the surface tension of complex, reactive organic-inorganic mixtures

    Science.gov (United States)

    Schwier, A. N.; Viglione, G. A.; Li, Z.; McNeill, V. Faye

    2013-11-01

    Atmospheric aerosols can contain thousands of organic compounds which impact aerosol surface tension, affecting aerosol properties such as heterogeneous reactivity, ice nucleation, and cloud droplet formation. We present new experimental data for the surface tension of complex, reactive organic-inorganic aqueous mixtures mimicking tropospheric aerosols. Each solution contained 2-6 organic compounds, including methylglyoxal, glyoxal, formaldehyde, acetaldehyde, oxalic acid, succinic acid, leucine, alanine, glycine, and serine, with and without ammonium sulfate. We test two semi-empirical surface tension models and find that most reactive, complex, aqueous organic mixtures which do not contain salt are well described by a weighted Szyszkowski-Langmuir (S-L) model which was first presented by Henning et al. (2005). Two approaches for modeling the effects of salt were tested: (1) the Tuckermann approach (an extension of the Henning model with an additional explicit salt term), and (2) a new implicit method proposed here which employs experimental surface tension data obtained for each organic species in the presence of salt used with the Henning model. We recommend the use of method (2) for surface tension modeling of aerosol systems because the Henning model (using data obtained from organic-inorganic systems) and Tuckermann approach provide similar modeling results and goodness-of-fit (χ2) values, yet the Henning model is a simpler and more physical approach to modeling the effects of salt, requiring less empirically determined parameters.

  14. Modeling and simulation for fewer-axis grinding of complex surface

    Science.gov (United States)

    Li, Zhengjian; Peng, Xiaoqiang; Song, Ci

    2017-10-01

    As the basis of fewer-axis grinding of complex surface, the grinding mathematical model is of great importance. A mathematical model of the grinding wheel was established, and then coordinate and normal vector of the wheel profile could be calculated. Through normal vector matching at the cutter contact point and the coordinate system transformation, the grinding mathematical model was established to work out the coordinate of the cutter location point. Based on the model, interference analysis was simulated to find out the right position and posture of workpiece for grinding. Then positioning errors of the workpiece including the translation positioning error and the rotation positioning error were analyzed respectively, and the main locating datum was obtained. According to the analysis results, the grinding tool path was planned and generated to grind the complex surface, and good form accuracy was obtained. The grinding mathematical model is simple, feasible and can be widely applied.

  15. Effect of glutamic acid on copper sorption onto kaolinite. Batch experiments and surface complexation modeling

    Energy Technology Data Exchange (ETDEWEB)

    Karimzadeh, Lotfallah; Barthen, Robert; Gruendig, Marion; Franke, Karsten; Lippmann-Pipke, Johanna [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Reactive Transport; Stockmann, Madlen [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Surface Processes

    2017-06-01

    In this work, we study the mobility behavior of Cu(II) under conditions related to an alternative, neutrophile biohydrometallurgical Cu(II) leaching approach. Sorption of copper onto kaolinite influenced by glutamic acid (Glu) was investigated in the presence of 0.01 M NaClO{sub 4} by means of binary and ternary batch adsorption measurements over a pH range of 4 to 9 and surface complexation modeling.

  16. Effect of glutamic acid on copper sorption onto kaolinite. Batch experiments and surface complexation modeling

    International Nuclear Information System (INIS)

    Karimzadeh, Lotfallah; Barthen, Robert; Gruendig, Marion; Franke, Karsten; Lippmann-Pipke, Johanna; Stockmann, Madlen

    2017-01-01

    In this work, we study the mobility behavior of Cu(II) under conditions related to an alternative, neutrophile biohydrometallurgical Cu(II) leaching approach. Sorption of copper onto kaolinite influenced by glutamic acid (Glu) was investigated in the presence of 0.01 M NaClO_4 by means of binary and ternary batch adsorption measurements over a pH range of 4 to 9 and surface complexation modeling.

  17. Surface complexation modeling of uranyl adsorption on corrensite from the Waste Isolation Pilot Plant Site

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sang-Won; Leckie, J.O. [Stanford Univ., CA (United States); Siegel, M.D. [Sandia National Labs., Albuquerque, NM (United States)

    1995-09-01

    Corrensite is the dominant clay mineral in the Culebra Dolomite at the Waste Isolation Pilot Plant. The surface characteristics of corrensite, a mixed chlorite/smectite clay mineral, have been studied. Zeta potential measurements and titration experiments suggest that the corrensite surface contains a mixture of permanent charge sites on the basal plane and SiOH and AlOH sites with a net pH-dependent charge at the edge of the clay platelets. Triple-layer model parameters were determined by the double extrapolation technique for use in chemical speciation calculations of adsorption reactions using the computer program HYDRAQL. Batch adsorption studies showed that corrensite is an effective adsorbent for uranyl. The pH-dependent adsorption behavior indicates that adsorption occurs at the edge sites. Adsorption studies were also conducted in the presence of competing cations and complexing ligands. The cations did not affect uranyl adsorption in the range studied. This observation lends support to the hypothesis that uranyl adsorption occurs at the edge sites. Uranyl adsorption was significantly hindered by carbonate. It is proposed that the formation of carbonate uranyl complexes inhibits uranyl adsorption and that only the carbonate-free species adsorb to the corrensite surface. The presence of the organic complexing agents EDTA and oxine also inhibits uranyl sorption.

  18. Surface complexation modeling of uranyl adsorption on corrensite from the Waste Isolation Pilot Plant Site

    International Nuclear Information System (INIS)

    Park, Sang-Won; Leckie, J.O.; Siegel, M.D.

    1995-09-01

    Corrensite is the dominant clay mineral in the Culebra Dolomite at the Waste Isolation Pilot Plant. The surface characteristics of corrensite, a mixed chlorite/smectite clay mineral, have been studied. Zeta potential measurements and titration experiments suggest that the corrensite surface contains a mixture of permanent charge sites on the basal plane and SiOH and AlOH sites with a net pH-dependent charge at the edge of the clay platelets. Triple-layer model parameters were determined by the double extrapolation technique for use in chemical speciation calculations of adsorption reactions using the computer program HYDRAQL. Batch adsorption studies showed that corrensite is an effective adsorbent for uranyl. The pH-dependent adsorption behavior indicates that adsorption occurs at the edge sites. Adsorption studies were also conducted in the presence of competing cations and complexing ligands. The cations did not affect uranyl adsorption in the range studied. This observation lends support to the hypothesis that uranyl adsorption occurs at the edge sites. Uranyl adsorption was significantly hindered by carbonate. It is proposed that the formation of carbonate uranyl complexes inhibits uranyl adsorption and that only the carbonate-free species adsorb to the corrensite surface. The presence of the organic complexing agents EDTA and oxine also inhibits uranyl sorption

  19. Lessons Learned From Microkernel Verification — Specification is the New Bottleneck

    Directory of Open Access Journals (Sweden)

    Thorsten Bormer

    2012-11-01

    Full Text Available Software verification tools have become a lot more powerful in recent years. Even verification of large, complex systems is feasible, as demonstrated in the L4.verified and Verisoft XT projects. Still, functional verification of large software systems is rare – for reasons beyond the large scale of verification effort needed due to the size alone. In this paper we report on lessons learned for verification of large software systems based on the experience gained in microkernel verification in the Verisoft XT project. We discuss a number of issues that impede widespread introduction of formal verification in the software life-cycle process.

  20. Enhancing the magnetic anisotropy of maghemite nanoparticles via the surface coordination of molecular complexes

    Science.gov (United States)

    Prado, Yoann; Daffé, Niéli; Michel, Aude; Georgelin, Thomas; Yaacoub, Nader; Grenèche, Jean-Marc; Choueikani, Fadi; Otero, Edwige; Ohresser, Philippe; Arrio, Marie-Anne; Cartier-dit-Moulin, Christophe; Sainctavit, Philippe; Fleury, Benoit; Dupuis, Vincent; Lisnard, Laurent; Fresnais, Jérôme

    2015-01-01

    Superparamagnetic nanoparticles are promising objects for data storage or medical applications. In the smallest—and more attractive—systems, the properties are governed by the magnetic anisotropy. Here we report a molecule-based synthetic strategy to enhance this anisotropy in sub-10-nm nanoparticles. It consists of the fabrication of composite materials where anisotropic molecular complexes are coordinated to the surface of the nanoparticles. Reacting 5 nm γ-Fe2O3 nanoparticles with the [CoII(TPMA)Cl2] complex (TPMA: tris(2-pyridylmethyl)amine) leads to the desired composite materials and the characterization of the functionalized nanoparticles evidences the successful coordination—without nanoparticle aggregation and without complex dissociation—of the molecular complexes to the nanoparticles surface. Magnetic measurements indicate the significant enhancement of the anisotropy in the final objects. Indeed, the functionalized nanoparticles show a threefold increase of the blocking temperature and a coercive field increased by one order of magnitude. PMID:26634987

  1. Surface Complexation Modeling of Fluoride Adsorption by Soil and the Role of Dissolved Aluminum on Adsorption

    Science.gov (United States)

    Padhi, S.; Tokunaga, T.

    2017-12-01

    Adsorption of fluoride (F) on soil can control the mobility of F and subsequent contamination of groundwater. Hence, accurate evaluation of adsorption equilibrium is a prerequisite for understanding transport and fate of F in the subsurface. While there have been studies for the adsorption behavior of F with respect to single mineral constituents based on surface complexation models (SCM), F adsorption to natural soil in the presence of complexing agents needs much investigation. We evaluated the adsorption processes of F on a natural granitic soil from Tsukuba, Japan, as a function of initial F concentration, ionic strength, and initial pH. A SCM was developed to model F adsorption behavior. Four possible surface complexation reactions were postulated with and without including dissolved aluminum (Al) and Al-F complex sorption. Decrease in F adsorption with the increase in initial pH was observed in between the initial pH range of 4 to 9, and a decrease in the rate of the reduction of adsorbed F with respect to the increase in the initial pH was observed in the initial pH range of 5 to 7. Ionic strength variation in the range of 0 to 100mM had insignificant effect on F removal. Changes in solution pH were observed by comparing the solution before and after F adsorption experiments. At acidic pH, the solution pH increased, whereas at alkaline pH, the solution pH decreased after equilibrium. The SCM including dissolved Al and the adsorption of Al-F complex can simulate the experimental results quite successfully. Also, including dissolved Al and the adsorption of Al-F complex to the model explained the change in solution pH after F adsorption.

  2. Restoration of an object from its complex cross sections and surface smoothing of the object

    International Nuclear Information System (INIS)

    Agui, Takeshi; Arai, Kiyoshi; Nakajima, Masayuki

    1990-01-01

    In clinical medicine, restoring the surface of a three-dimensional object from its set of parallel cross sections obtained by CT or MRI is useful in diagnoses. A method of connecting a pair of contours on neighboring cross sections to each other by triangular patches is generally used for this restoration. This method, however, has the complexity of triangulation algorithm, and requires the numerous quantity of calculations when surface smoothing is executed. In our new method, the positions of sampling points are expressed in cylindrical coordinates. Sampling points including auxiliary points are extracted and connected using simple algorithm. Surface smoothing is executed by moving sampling points. This method extends the application scope of restoring objects by triangulation. (author)

  3. Functionalized granular activated carbon and surface complexation with chromates and bi-chromates in wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Singha, Somdutta; Sarkar, Ujjaini, E-mail: usarkar@chemical.jdvu.ac.in; Luharuka, Pallavi

    2013-03-01

    Cr(VI) is present in the aqueous medium as chromate (CrO{sub 4}{sup 2−}) and bi-chromate (HCrO{sub 4}{sup −}). Functionalized granular activated carbons (FACs) are used as adsorbents in the treatment of wastewaters containing hexavalent chromium. The FACs are prepared by chemical modifications of granular activated carbons (GACs) using functionalizing agents like HNO{sub 3}, HCl and HF. The Brunauer, Emmett and Teller surface areas of FAC-HCl (693.5 m{sup 2}/g), FAC-HNO{sub 3} (648.8 m{sup 2}/g) and FAC-HF (726.2 m{sup 2}/g) are comparable to the GAC (777.7 m{sup 2}/g). But, the adsorption capacity of each of the FAC-HNO{sub 3}, FAC-HCl and FAC-HF is found to be higher than the GAC. The functional groups play an important role in the adsorption process and pH has practically no role in this specific case. The FACs have hydrophilic protonated external surfaces in particular, along with the functional surface sites capable to make complexes with the CrO{sub 4}{sup 2−} and HCrO{sub 4}{sup −} present. Surface complex formation is maximized in the order FAC-HNO{sub 3} > FAC-HF > FAC-HCl, in proportion to the total surface acidity. This is also confirmed by the well-known pseudo second-order kinetic model. Physi-sorption equilibrium isotherms are parameterized by using standard Freundlich and Langmuir models. Langmuir fits better. The formation of surface complexes with the functional groups and hexavalent chromium is also revealed in the images of field emission scanning electron micrograph; energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy analysis after adsorption. The intra-particle diffusion is not the only rate-controlling factor. The Boyd's film diffusion model fits very well with R{sup 2} as high as 98.1% for FAC-HNO{sub 3}. This result demonstrates that the functionalization of the GAC by acid treatments would increase the diffusion rate, predominantly with a boundary layer diffusion effect. - Highlights: ► Physico

  4. Composition and microstructure alteration of triticale grain surface after processing by enzymes of cellulase complex

    Directory of Open Access Journals (Sweden)

    Elena Kuznetsova

    2016-01-01

    Full Text Available It is found that the pericarp tissue of grain have considerable strength and stiffness, that has an adverse effect on quality of whole-grain bread. Thereby, there exists the need for preliminary chemical and biochemical processing of durable cell walls before industrial use. Increasingly used in the production of bread finds an artificial hybrid of the traditional grain crops of wheat and rye - triticale, grain which has high nutritional value. The purpose of this research was to evaluate the influence of cellulose complex (Penicillium canescens enzymes on composition and microstructure alteration of triticale grain surface, for grain used in baking. Triticale grain was processed by cellulolytic enzyme preparations with different composition (producer is Penicillium canescens. During experiment it is found that triticale grain processing by enzymes of cellulase complex leads to an increase in the content of water-soluble pentosans by 36.3 - 39.2%. The total amount of low molecular sugars increased by 3.8 - 10.5 %. Studies show that under the influence of enzymes the microstructure of the triticale grain surface is changing. Microphotographs characterizing grain surface structure alteration in dynamic (every 2 hours during 10 hours of substrate hydrolysis are shown. It is found that the depth and direction of destruction process for non-starch polysaccharides of grain integument are determined by the composition of the enzyme complex preparation and duration of exposure. It is found, that xylanase involved in the modification of hemicelluloses fiber having both longitudinal and radial orientation. Hydrolysis of non-starch polysaccharides from grain shells led to increase of antioxidant activity. Ferulic acid was identified in alcoholic extract of triticale grain after enzymatic hydrolysis under the influence of complex preparation containing cellulase, xylanase and β-glucanase. Grain processing by independent enzymes containing in complex

  5. Early bone anchorage to micro- and nano-topographically complex implant surfaces in hyperglycemia.

    Science.gov (United States)

    Ajami, Elnaz; Bell, Spencer; Liddell, Robert S; Davies, John E

    2016-07-15

    The aim of this work was to investigate the effect of implant surface design on early bone anchorage in the presence of hyperglycemia. 108 Wistar rats were separated into euglycemic (EG) controls and STZ-treated hyperglycemic (HG) groups, and received bilateral femoral custom rectangular implants of two surface topographies: grit blasted (GB) and grit-blast with a superimposed calcium phosphate nanotopography (GB-DCD). The peri-implant bone was subjected to a tensile disruption test 5, 7, and 9days post-operatively (n=28/time point); the force was measured; and the residual peri-implant bone was observed by scanning electron microscopy (SEM). Disruption forces at 5days were not significantly different from zero for the GB implants (p=0.24) in either metabolic group; but were for GB+DCD implants in both metabolic groups (pmicro-surfaced implants showed significantly different disruption forces at all time points (e.g. >15N and implants, as all values were very low (implant bone showed compromised intra-fibrillar collagen mineralization in hyperglycemia, while inter-fibrillar and cement line mineralization remained unaffected. Enhanced bone anchorage to the implant surfaces was observed on the nanotopographically complex surface independent of metabolic group. The compromised intra-fibrillar mineralization observed provides a mechanism by which early bone mineralization is affected in hyperglycemia. It is generally accepted that the hyperglycemia associated with diabetes mellitus compromises bone quality, although the mechanism by which this occurs is unknown. Uncontrolled hyperglycemia is therefore a contra-indication for bone implant placement. It is also known that nano-topographically complex implant surfaces accelerate early peri-implant healing. In this report we show that, in our experimental model, nano-topographically complex surfaces can mitigate the compromised bone healing seen in hyperglycemia. Importantly, we also provide a mechanistic explanation for

  6. Surface complexation modeling of uranium (Vi) retained onto zirconium diphosphate in presence of organic acids

    International Nuclear Information System (INIS)

    Almazan T, M. G.; Garcia G, N.; Ordonez R, E.

    2010-10-01

    In the field of nuclear waste disposal, predictions regarding radionuclide migration through the geosphere, have to take account the effects of natural organic matter. This work presents an investigation of interaction mechanisms between U (Vi) and zirconium diphosphate (ZrP 2 O 7 ) in presence of organic acids (citric acid and oxalic acid). The retention reactions were previously examined using a batch equilibrium method. Previous results showed that U (Vi) retention was more efficient when citric acid or oxalic acid was present in solid surface at lower ph values. In order to determine the retention equilibria for both systems studied, a phosphorescence spectroscopy study was carried out. The experimental data were then fitted using the Constant Capacitance Model included in the FITEQL4.0 code. Previous results concerning surface characterization of ZrP 2 O 7 (surface sites density and surface acidity constants) were used to constraint the modeling. The best fit for U (Vi)/citric acid/ZrP 2 O 7 and U (Vi)/oxalic acid/ZrP 2 O 7 systems considered the formation of a ternary surface complex. (Author)

  7. Spectroscopic evidence for ternary surface complexes in the lead(II)-malonic acid-hematite system

    Science.gov (United States)

    Lenhart, J.J.; Bargar, J.R.; Davis, J.A.

    2001-01-01

    Using extended X-ray absorption fine structure (EXAFS) and attenuated total reflectance Fourier-transform infrared (ATR-FTIR) measurements, we examined the sorption of Pb(II) to hematite in the presence of malonic acid. Pb LIII-edge EXAFS measurements performed in the presence of malonate indicate the presence of both Fe and C neighbors, suggesting that a major fraction of surface-bound malonate is bonded to adsorbed Pb(II). In the absence of Pb(II), ATR-FTIR measurements of sorbed malonate suggest the formation of more than one malonate surface complex. The dissimilarity of the IR spectrum of malonate sorbed on hematite to those for aqueous malonate suggest at least one of the sorbed malonate species is directly coordinated to surface Fe atoms in an inner-sphere mode. In the presence of Pb, little change is seen in the IR spectrum for sorbed malonate, indicating that geometry of malonate as it coordinates to sorbed Pb(II) adions is similar to the geometry of malonate as it coordinates to Fe in the hematite surface. Fits of the raw EXAFS spectra collected from pH 4 to pH 8 result in average Pb-C distances of 2.98 to 3.14 A??, suggesting the presence of both four- and six-membered Pb-malonate rings. The IR results are consistent with this interpretation. Thus, our results suggest that malonate binds to sorbed Pb(II) adions, forming ternary metal-bridging surface complexes. ?? 2001 Academic Press.

  8. Surface complexation modeling of the effects of phosphate on uranium(VI) adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Romero-Gonzalez, M.R.; Cheng, T.; Barnett, M.O. [Auburn Univ., AL (United States). Dept. of Civil Engeneering; Roden, E.E. [Wisconsin Univ., Madison, WI (United States). Dept. of Geology and Geophysics

    2007-07-01

    Previous published data for the adsorption of U(VI) and/or phosphate onto amorphous Fe(III) oxides (hydrous ferric oxide, HFO) and crystalline Fe(III) oxides (goethite) was examined. These data were then used to test the ability of a commonly-used surface complexation model (SCM) to describe the adsorption of U(VI) and phosphate onto pure amorphous and crystalline Fe(III) oxides and synthetic goethite-coated sand, a surrogate for a natural Fe(III)-coated material, using the component additivity (CA) approach. Our modeling results show that this model was able to describe U(VI) adsorption onto both amorphous and crystalline Fe(III) oxides and also goethite-coated sand quite well in the absence of phosphate. However, because phosphate adsorption exhibits a stronger dependence on Fe(III) oxide type than U(VI) adsorption, we could not use this model to consistently describe phosphate adsorption onto both amorphous and crystalline Fe(III) oxides and goethite-coated sand. However, the effects of phosphate on U(VI) adsorption could be incorporated into the model to describe U(VI) adsorption to both amorphous and crystalline Fe(III) oxides and goethite-coated sand, at least for an initial approximation. These results illustrate both the potential and limitations of using surface complexation models developed from pure systems to describe metal/radionuclide adsorption under more complex conditions. (orig.)

  9. Surface complexation modeling of the effects of phosphate on uranium(VI) adsorption

    International Nuclear Information System (INIS)

    Romero-Gonzalez, M.R.; Cheng, T.; Barnett, M.O.; Roden, E.E.

    2007-01-01

    Previous published data for the adsorption of U(VI) and/or phosphate onto amorphous Fe(III) oxides (hydrous ferric oxide, HFO) and crystalline Fe(III) oxides (goethite) was examined. These data were then used to test the ability of a commonly-used surface complexation model (SCM) to describe the adsorption of U(VI) and phosphate onto pure amorphous and crystalline Fe(III) oxides and synthetic goethite-coated sand, a surrogate for a natural Fe(III)-coated material, using the component additivity (CA) approach. Our modeling results show that this model was able to describe U(VI) adsorption onto both amorphous and crystalline Fe(III) oxides and also goethite-coated sand quite well in the absence of phosphate. However, because phosphate adsorption exhibits a stronger dependence on Fe(III) oxide type than U(VI) adsorption, we could not use this model to consistently describe phosphate adsorption onto both amorphous and crystalline Fe(III) oxides and goethite-coated sand. However, the effects of phosphate on U(VI) adsorption could be incorporated into the model to describe U(VI) adsorption to both amorphous and crystalline Fe(III) oxides and goethite-coated sand, at least for an initial approximation. These results illustrate both the potential and limitations of using surface complexation models developed from pure systems to describe metal/radionuclide adsorption under more complex conditions. (orig.)

  10. An Evaluation of Fractal Surface Measurement Methods for Characterizing Landscape Complexity from Remote-Sensing Imagery

    Science.gov (United States)

    Lam, Nina Siu-Ngan; Qiu, Hong-Lie; Quattrochi, Dale A.; Emerson, Charles W.; Arnold, James E. (Technical Monitor)

    2001-01-01

    The rapid increase in digital data volumes from new and existing sensors necessitates the need for efficient analytical tools for extracting information. We developed an integrated software package called ICAMS (Image Characterization and Modeling System) to provide specialized spatial analytical functions for interpreting remote sensing data. This paper evaluates the three fractal dimension measurement methods: isarithm, variogram, and triangular prism, along with the spatial autocorrelation measurement methods Moran's I and Geary's C, that have been implemented in ICAMS. A modified triangular prism method was proposed and implemented. Results from analyzing 25 simulated surfaces having known fractal dimensions show that both the isarithm and triangular prism methods can accurately measure a range of fractal surfaces. The triangular prism method is most accurate at estimating the fractal dimension of higher spatial complexity, but it is sensitive to contrast stretching. The variogram method is a comparatively poor estimator for all of the surfaces, particularly those with higher fractal dimensions. Similar to the fractal techniques, the spatial autocorrelation techniques are found to be useful to measure complex images but not images with low dimensionality. These fractal measurement methods can be applied directly to unclassified images and could serve as a tool for change detection and data mining.

  11. Complexation of lysozyme with adsorbed PtBS-b-SCPI block polyelectrolyte micelles on silver surface.

    Science.gov (United States)

    Papagiannopoulos, Aristeidis; Christoulaki, Anastasia; Spiliopoulos, Nikolaos; Vradis, Alexandros; Toprakcioglu, Chris; Pispas, Stergios

    2015-01-20

    We present a study of the interaction of the positively charged model protein lysozyme with the negatively charged amphiphilic diblock polyelectrolyte micelles of poly(tert-butylstyrene-b-sodium (sulfamate/carboxylate)isoprene) (PtBS-b-SCPI) on the silver/water interface. The adsorption kinetics are monitored by surface plasmon resonance, and the surface morphology is probed by atomic force microscopy. The micellar adsorption is described by stretched-exponential kinetics, and the micellar layer morphology shows that the micelles do not lose their integrity upon adsorption. The complexation of lysozyme with the adsorbed micellar layers depends on the micelles arrangement and density in the underlying layer, and lysozyme follows the local morphology of the underlying roughness. When the micellar adsorbed amount is small, the layers show low capacity in protein complexation and low resistance in loading. When the micellar adsorbed amount is high, the situation is reversed. The adsorbed layers both with or without added protein are found to be irreversibly adsorbed on the Ag surface.

  12. Sorption of uranium (VI) on homoionic sodium smectite experimental study and surface complexation modeling.

    Science.gov (United States)

    Korichi, Smain; Bensmaili, Aicha

    2009-09-30

    This paper is an extension of a previous paper where the natural and purified clay in the homoionic Na form were physico-chemically characterized (doi:10.1016/j.clay.2008.04.014). In this study, the adsorption behavior of U (VI) on a purified Na-smectite suspension is studied using batch adsorption experiments and surface complexation modeling (double layer model). The sorption of uranium was investigated as a function of pH, uranium concentration, solid to liquid ratio, effect of natural organic matter (NOM) and NaNO(3) background electrolyte concentration. Using the MINTEQA2 program, the speciation of uranium was calculated as a function of pH and uranium concentration. Model predicted U (VI) aqueous speciation suggests that important aqueous species in the [U (VI)]=1mg/L and pH range 3-7 including UO(2)(2+), UO(2)OH(+), and (UO(2))(3)(OH)(5)(+). The concentration of UO(2)(2+) decreased and that of (UO(2))(3)(OH)(5)(+) increased with increasing pH. The potentiometric titration values and uptake of uranium in the sodium smectite suspension were simulated by FITEQL 4.0 program using a two sites model, which is composed of silicate and aluminum reaction sites. We compare the acidity constants values obtained by potentiometric titration from the purified sodium smectite with those obtained from single oxides (quartz and alpha-alumina), taking into account the surface heterogeneity and the complex nature of natural colloids. We investigate the uranium sorption onto purified Na-smectite assuming low, intermediate and high edge site surfaces which are estimated from specific surface area percentage. The sorption data is interpreted and modeled as a function of edge site surfaces. A relationship between uranium sorption and total site concentration was confirmed and explained through variation in estimated edge site surface value. The modeling study shows that, the convergence during DLM modeling is related to the best estimation of the edge site surface from the N(2

  13. Physics Verification Overview

    Energy Technology Data Exchange (ETDEWEB)

    Doebling, Scott William [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-09-12

    The purpose of the verification project is to establish, through rigorous convergence analysis, that each ASC computational physics code correctly implements a set of physics models and algorithms (code verification); Evaluate and analyze the uncertainties of code outputs associated with the choice of temporal and spatial discretization (solution or calculation verification); and Develop and maintain the capability to expand and update these analyses on demand. This presentation describes project milestones.

  14. Surface reaction of SnII on goethite (α-FeOOH): surface complexation, redox reaction, reductive dissolution, and phase transformation.

    Science.gov (United States)

    Dulnee, Siriwan; Scheinost, Andreas C

    2014-08-19

    To elucidate the potential risk of (126)Sn migration from nuclear waste repositories, we investigated the surface reactions of Sn(II) on goethite as a function of pH and Sn(II) loading under anoxic condition with O2 level redox state and surface structure were investigated by Sn K edge X-ray absorption spectroscopy (XAS), goethite phase transformations were investigated by high-resolution transmission electron microscopy and selected area electron diffraction. The results demonstrate the rapid and complete oxidation of Sn(II) by goethite and formation of Sn(IV) (1)E and (2)C surface complexes. The contribution of (2)C complexes increases with Sn loading. The Sn(II) oxidation leads to a quantitative release of Fe(II) from goethite at low pH, and to the precipitation of magnetite at higher pH. To predict Sn sorption, we applied surface complexation modeling using the charge distribution multisite complexation approach and the XAS-derived surface complexes. Log K values of 15.5 ± 1.4 for the (1)E complex and 19.2 ± 0.6 for the (2)C complex consistently predict Sn sorption across pH 2-12 and for two different Sn loadings and confirm the strong retention of Sn(II) even under anoxic conditions.

  15. Surface Complexation Modeling in Variable Charge Soils: Prediction of Cadmium Adsorption

    Directory of Open Access Journals (Sweden)

    Giuliano Marchi

    2015-10-01

    Full Text Available ABSTRACT Intrinsic equilibrium constants for 22 representative Brazilian Oxisols were estimated from a cadmium adsorption experiment. Equilibrium constants were fitted to two surface complexation models: diffuse layer and constant capacitance. Intrinsic equilibrium constants were optimized by FITEQL and by hand calculation using Visual MINTEQ in sweep mode, and Excel spreadsheets. Data from both models were incorporated into Visual MINTEQ. Constants estimated by FITEQL and incorporated in Visual MINTEQ software failed to predict observed data accurately. However, FITEQL raw output data rendered good results when predicted values were directly compared with observed values, instead of incorporating the estimated constants into Visual MINTEQ. Intrinsic equilibrium constants optimized by hand calculation and incorporated in Visual MINTEQ reliably predicted Cd adsorption reactions on soil surfaces under changing environmental conditions.

  16. Stability of nano-metric colloidal dispersions of titanium: effect of surface complexation

    International Nuclear Information System (INIS)

    Peyre, Veronique

    1996-01-01

    This research thesis reports the study of the adsorption of small organic molecules at the surface of nano-particles of mineral oxides (zirconia), and of its effects on the stability of the colloidal dispersion. Adsorption has been quantified by adsorption isotherms and surface titrations. Processes and mechanisms are thus discussed with respect to pH. The influence of various protecting molecules (acetyl acetone, but also acetic acid, citric acid and diethanolamine) has been studied, and notably highlighted the role of the outer face of the complexing agent in the assessment of reactions between particles which govern the compression and re-dispersability properties of protected dispersions. This study is performed by osmotic pressure measurements and by X-ray diffusion at small angles, completed by statistical mechanics calculations [fr

  17. Ultrasonic detection technology based on joint robot on composite component with complex surface

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Juan; Xu, Chunguang; Zhang, Lan [School of Mechanical Engineering, Beijing Institute of Technology, Beijing (China)

    2014-02-18

    Some components have complex surface, such as the airplane wing and the shell of a pressure vessel etc. The quality of these components determines the reliability and safety of related equipment. Ultrasonic nondestructive detection is one of the main methods used for testing material defects at present. In order to improve the testing precision, the acoustic axis of the ultrasonic transducer should be consistent with the normal direction of the measured points. When we use joint robots, automatic ultrasonic scan along the component surface normal direction can be realized by motion trajectory planning and coordinate transformation etc. In order to express the defects accurately and truly, the robot position and the signal of the ultrasonic transducer should be synchronized.

  18. Ultraviolet photoemission spectroscopy of hydrogen complex deactivation on InP:Zn(1 0 0) surfaces

    International Nuclear Information System (INIS)

    Williams, M.D.; Williams, S.C.; Yasharahla, S.A.; Jallow, N.

    2007-01-01

    Ultraviolet photoemission spectroscopy is used to study the kinetics of the H-Zn complex deactivation in Zn doped InP(1 0 0). Hydrogen injected into the material electronically passivates the local carrier concentration. Reverse-biased anneals of the InP under ultra-high vacuum show a dramatic change in the work function of the material with increasing temperature. Spectral features are also shown to be sensitive to sample temperature. To our knowledge, we show the first view of hydrogen retrapping at the surface using photoemission spectroscopy. A simple photoelectron threshold energy analysis shows the state of charge compensation of the material

  19. Surface complexation modelling applied to the sorption of nickel on silica

    International Nuclear Information System (INIS)

    Olin, M.

    1995-10-01

    The modelling based on a mechanistic approach, of a sorption experiment is presented in the report. The system chosen for experiments (nickel + silica) is modelled by using literature values for some parameters, the remainder being fitted by existing experimental results. All calculations are performed by HYDRAQL, a model planned especially for surface complexation modelling. Allmost all the calculations are made by using the Triple-Layer Model (TLM) approach, which appeared to be sufficiently flexible for the silica system. The report includes a short description of mechanistic sorption models, input data, experimental results and modelling results (mostly graphical presentations). (13 refs., 40 figs., 4 tabs.)

  20. The surface chemistry of divalent metal carbonate minerals; a critical assessment of surface charge and potential data using the charge distribution multi-site ion complexation model

    NARCIS (Netherlands)

    Wolthers, M.; Charlet, L.; Van Cappellen, P.

    2008-01-01

    The Charge Distribution MUltiSite Ion Complexation or CD–MUSIC modeling approach is used to describe the chemical structure of carbonate mineralaqueous solution interfaces. The new model extends existing surface complexation models of carbonate minerals, by including atomic scale information on

  1. HIFU scattering by the ribs: constrained optimisation with a complex surface impedance boundary condition

    Science.gov (United States)

    Gélat, P.; ter Haar, G.; Saffari, N.

    2014-04-01

    High intensity focused ultrasound (HIFU) enables highly localised, 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 established treatment modalities such as resection, chemotherapy and ionising 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 minimising 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 (BE) approach based on a Generalised 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 [1]. Dissipative mechanisms inside the propagating medium have since been implemented, together with a complex surface impedance condition at the surface of the ribs. A reformulation of the boundary element equations as a constrained optimisation problem was carried out to determine the complex surface velocities of a multi-element HIFU array which generated the acoustic pressure field that best fitted a required acoustic pressure distribution in a least-squares sense. This was done whilst ensuring that an acoustic dose rate parameter at the surface of the ribs was kept below a specified threshold. The methodology was tested at an

  2. Joint body and surface wave tomography applied to the Toba caldera complex (Indonesia)

    Science.gov (United States)

    Jaxybulatov, Kairly; Koulakov, Ivan; Shapiro, Nikolai

    2016-04-01

    We developed a new algorithm for a joint body and surface wave tomography. The algorithm is a modification of the existing LOTOS code (Koulakov, 2009) developed for local earthquake tomography. The input data for the new method are travel times of P and S waves and dispersion curves of Rayleigh and Love waves. The main idea is that the two data types have complementary sensitivities. The body-wave data have good resolution at depth, where we have enough crossing rays between sources and receivers, whereas the surface waves have very good near-surface resolution. The surface wave dispersion curves can be retrieved from the correlations of the ambient seismic noise and in this case the sampled path distribution does not depend on the earthquake sources. The contributions of the two data types to the inversion are controlled by the weighting of the respective equations. One of the clearest cases where such approach may be useful are volcanic systems in subduction zones with their complex magmatic feeding systems that have deep roots in the mantle and intermediate magma chambers in the crust. In these areas, the joint inversion of different types of data helps us to build a comprehensive understanding of the entire system. We apply our algorithm to data collected in the region surrounding the Toba caldera complex (north Sumatra, Indonesia) during two temporary seismic experiments (IRIS, PASSCAL, 1995, GFZ, LAKE TOBA, 2008). We invert 6644 P and 5240 S wave arrivals and ~500 group velocity dispersion curves of Rayleigh and Love waves. We present a series of synthetic tests and real data inversions which show that joint inversion approach gives more reliable results than the separate inversion of two data types. Koulakov, I., LOTOS code for local earthquake tomographic inversion. Benchmarks for testing tomographic algorithms, Bull. seism. Soc. Am., 99(1), 194-214, 2009, doi:10.1785/0120080013

  3. Surface Complexation Modeling of Calcite Zeta Potential Measurement in Mixed Brines for Carbonate Wettability Characterization

    Science.gov (United States)

    Song, J.; Zeng, Y.; Biswal, S. L.; Hirasaki, G. J.

    2017-12-01

    We presents zeta potential measurements and surface complexation modeling (SCM) of synthetic calcite in various conditions. The systematic zeta potential measurement and the proposed SCM provide insight into the role of four potential determining cations (Mg2+, SO42- , Ca2+ and CO32-) and CO2 partial pressure in calcite surface charge formation and facilitate the revealing of calcite wettability alteration induced by brines with designed ionic composition ("smart water"). Brines with varying potential determining ions (PDI) concentration in two different CO2 partial pressure (PCO2) are investigated in experiments. Then, a double layer SCM is developed to model the zeta potential measurements. Moreover, we propose a definition for contribution of charged surface species and quantitatively analyze the variation of charged species contribution when changing brine composition. After showing our model can accurately predict calcite zeta potential in brines containing mixed PDIs, we apply it to predict zeta potential in ultra-low and pressurized CO2 environments for potential applications in carbonate enhanced oil recovery including miscible CO2 flooding and CO2 sequestration in carbonate reservoirs. Model prediction reveals that pure calcite surface will be positively charged in all investigated brines in pressurized CO2 environment (>1atm). Moreover, the sensitivity of calcite zeta potential to CO2 partial pressure in the various brine is found to be in the sequence of Na2CO3 > Na2SO4 > NaCl > MgCl2 > CaCl2 (Ionic strength=0.1M).

  4. Surface phase transformations, surface complexation and solubilities of hydroxyapatite in the absence/presence of Cd(II) and EDTA

    International Nuclear Information System (INIS)

    Viipsi, Karin; Sjöberg, Staffan; Shchukarev, Andrey; Tõnsuaadu, Kaia

    2012-01-01

    The removal of Cd from aqueous solutions by hydroxyapatite (HAP) was investigated with and without EDTA being present. Batch experiments were carried out using synthetic hydroxyapatite with Ca/P 1.57 and a specific surface area of 37.5 m 2 /g in the pH range 4–9 (25 °C; 0.1 M KNO 3 ). The surface composition of the solid phases were analysed by X-ray Photoelectron Spectroscopy (XPS). The surface layer of HAP was found to undergo a phase transformation with a (Ca + Cd)/P atomic ratio of 1.4 and the involvement of an ion exchange process (Ca 2+ ↔ Cd 2+ ). The amount of Cd removed from the solution increased with increasing pH, reaching ≈100% at pH 9. In the presence of EDTA Cd removal was reduced due to the formation of [CdEDTA] 2− in solution. The solubility of HAP increases in the presence of EDTA at pH values above 5, mainly due to the formation of [CaEDTA] 2− . In contrast to this, the solubility was found to decrease in the presence of Cd 2+ and CdEDTA 2− . Using XPS the formation of a Cd-enriched HAP surface was found, which was interpreted as the formation of a solid solution of the general composition: Ca 8.4-x Cd x (HPO 4 ) 1.6 (PO 4 ) 4.4 (OH) 0.4 . The information from the chemical analyses and XPS data was used to design an equilibrium model that takes into account dissolution, solution and surface complexation, as well as possible phase transformations. The total concentration of Ca, phosphate, EDTA, and Cd in solution were used in the equilibrium analysis. In the calculations the computer code WinSGW, which is based on the SOLGASWATER algorithm, was used. The following equilibria and compositions of the solid solutions were found to give the best fit to experimental data: logK s (Ca 7.6 Cd 0.8 (HPO 4 ) 1.6 (PO 4 ) 4.4 (OH) 0.4 (s)+4.8H + ⇋7.6Ca 2+ +0.8Cd 2+ +6HPO 4 2- +0.4H 2 O)=-28.03±0.07. The corresponding value for the composition Ca 5.6 Cd 2.8 (HPO 4 ) 1.6 (PO 4 ) 4.4 (OH) 0.4 (s) is −27.39 ± 0.06. The proposed model can be used

  5. Verification and the safeguards legacy

    International Nuclear Information System (INIS)

    Perricos, Demetrius

    2001-01-01

    ; qualitative and quantitative measurements of nuclear material; familiarity and access to sensitive technologies related to detection, unattended verification systems, containment/surveillance and sensors; examination and verification of design information of large and complex facilities; theoretical and practical aspects of technologies relevant to verification objectives; analysis of inspection findings and evaluation of their mutual consistency; negotiations on technical issues with facility operators and State authorities. This experience is reflected in the IAEA Safeguards Manual which sets out the policies and procedures to be followed in the inspection process as well as in the Safeguards Criteria which provide guidance for verification, evaluation and analysis of the inspection findings. The IAEA infrastructure and its experience with verification permitted in 1991 the organization to respond immediately and successfully to the tasks required by the Security Council Resolution 687(1991) for Iraq as well as to the tasks related to the verification of completeness and correctness of the initial declarations in the cases of the DPRK. and of S. Africa. In the case of Iraq the discovery of its undeclared programs was made possible through the existing verification system enhanced by additional access rights, information and application of modern detection technology. Such discoveries made it evident that there was a need for an intensive development effort to strengthen the safeguards system to develop a capability to detect undeclared activities. For this purpose it was recognized that there was need for additional and extended a) access to information, b) access to locations. It was also obvious that access to the Security Council, to bring the IAEA closer to the body responsible for maintenance of international peace and security, would be a requirement for reporting periodically on non-proliferation and the results of the IAEA's verification activities. While the case

  6. Investigations of surface-tension effects due to small-scale complex boundaries

    Science.gov (United States)

    Feng, Jiansheng

    these two different types of surfaces differed by about 50° ˜ 60°, with the low-adhesion surfaces at about 120° ˜ 130° and the high-adhesion surfaces at about 70° ˜ 80°. Characterizations of both the microscopic structures and macroscopic wetting properties of these product surfaces allowed us to pinpoint the structural features responsible for specific wetting properties. It is found that the advancing contact angle was mainly determined by the primary structures while the receding contact angle is largely affected by the side-wall slope of the secondary features. This study established a platform for further exploration of the structure aspects of surface wettability. In the third and final project (Chapter 4), we demonstrated a new type of microfluidic channel that enable asymmetric wicking of wetting fluids based on structure-induced direction-dependent surface-tension effect. By decorating the side-walls of open microfluidic channels with tilted fins, we were able to experimentally demonstrate preferential wicking behaviors of various IPA-water mixtures with a range of contact angles in these channels. A simplified 2D model was established to explain the wicking asymmetry, and a complete 3D model was developed to provide more accurate quantitative predictions. The design principles developed in this study provide an additional scheme for controlling the spreading of fluids. The research presented in this dissertation spreads out across a wide range of physical phenomena (wicking, wetting, and capillarity), and involves a number of computational and experimental techniques, yet all of these projects are intrinsically united under a common theme: we want to better understand how simple fluids respond to small-scale complex surface structures as manifestations of surface-tension effects. We hope our findings can serve as building blocks for a larger scale endeavor of scientific research and engineering development. After all, the pursue of knowledge is most

  7. Formation mechanism of a silane-PVA/PVAc complex film on a glass fiber surface.

    Science.gov (United States)

    Repovsky, Daniel; Jane, Eduard; Palszegi, Tibor; Slobodnik, Marek; Velic, Dusan

    2013-10-21

    Mechanical properties of glass fiber reinforced composite materials are affected by fiber sizing. A complex film formation, based on a silane film and PVA/PVAc (polyvinyl alcohol/polyvinyl acetate) microspheres on a glass fiber surface is determined at 1) the nanoscale by using atomic force microscopy (AFM), and 2) the macroscale by using the zeta potential. Silane groups strongly bind through the Si-O-Si bond to the glass surface, which provides the attachment mechanism as a coupling agent. The silane groups form islands, a homogeneous film, as well as empty sites. The average roughness of the silanized surface is 6.5 nm, whereas it is only 0.6 nm for the non-silanized surface. The silane film vertically penetrates in a honeycomb fashion from the glass surface through the deposited PVA/PVAc microspheres to form a hexagonal close pack structure. The silane film not only penetrates, but also deforms the PVA/PVAc microspheres from the spherical shape in a dispersion to a ellipsoidal shape on the surface with average dimensions of 300/600 nm. The surface area value Sa represents an area of PVA/PVAc microspheres that are not affected by the silane penetration. The areas are found to be 0.2, 0.08, and 0.03 μm(2) if the ellipsoid sizes are 320/570, 300/610, and 270/620 nm for silane concentrations of 0, 3.8, and 7.2 μg mL(-1), respectively. The silane film also moves PVA/PVAc microspheres in the process of complex film formation, from the low silane concentration areas to the complex film area providing enough silane groups to stabilize the structure. The values for the residual silane honeycomb structure heights (Ha ) are 6.5, 7, and 12 nm for silane concentrations of 3.8, 7.2, and 14.3 μg mL(-1), respectively. The pH-dependent zeta-potential results suggest a specific role of the silane groups with effects on the glass fiber surface and also on the PVA/PVAc microspheres. The non-silanized glass fiber surface and the silane film have similar zeta potentials ranging

  8. Cell surface clustering of Cadherin adhesion complex induced by antibody coated beads

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Cadherin receptors mediate cell-cell adhesion, signal transduction and assembly of cytoskeletons. How a single transmembrane molecule Cadherin can be involved in multiple functions through modulating its binding activities with many membrane adhesion molecules and cytoskeletal components is an unanswered question which can be elucidated by clues from bead experiments. Human lung cells expressing N-Cadherin were examined. After co-incubation with anti-N-Cadherin monoclonal antibody coated beads, cell surface clustering of N-Cadherin was induced. Immunofluorescent detection demonstrated that in addition to Cadherin, β-Catenin, α-Catenin, α-Actinin and Actin fluorescence also aggregated respectively at the membrane site of bead attachment. Myosin heavy chain (MHC), another major component of Actin cytoskeleton, did not aggregate at the membrane site of bead attachment. Adhesion unrelated protein Con A and polylysine conjugated beads did not induce the clustering of adhesion molecules. It is indicated that the Cadherin/Catenins/α-Actinin/Actin complex is formed at Cadherin mediated cell adherens junction; occupancy and cell surface clustering of Cadherin is crucial for the formation of Cadherin adhesion protein complexes.

  9. Transmission X-ray scattering as a probe for complex liquid-surface structures

    Energy Technology Data Exchange (ETDEWEB)

    Fukuto, Masafumi; Yang, Lin; Nykypanchuk, Dmytro; Kuzmenko, Ivan

    2016-01-28

    The need for functional materials calls for increasing complexity in self-assembly systems. As a result, the ability to probe both local structure and heterogeneities, such as phase-coexistence and domain morphologies, has become increasingly important to controlling self-assembly processes, including those at liquid surfaces. The traditional X-ray scattering methods for liquid surfaces, such as specular reflectivity and grazing-incidence diffraction, are not well suited to spatially resolving lateral heterogeneities due to large illuminated footprint. A possible alternative approach is to use scanning transmission X-ray scattering to simultaneously probe local intermolecular structures and heterogeneous domain morphologies on liquid surfaces. To test the feasibility of this approach, transmission small- and wide-angle X-ray scattering (TSAXS/TWAXS) studies of Langmuir films formed on water meniscus against a vertically immersed hydrophilic Si substrate were recently carried out. First-order diffraction rings were observed in TSAXS patterns from a monolayer of hexagonally packed gold nanoparticles and in TWAXS patterns from a monolayer of fluorinated fatty acids, both as a Langmuir monolayer on water meniscus and as a Langmuir–Blodgett monolayer on the substrate. The patterns taken at multiple spots have been analyzed to extract the shape of the meniscus surface and the ordered-monolayer coverage as a function of spot position. These results, together with continual improvement in the brightness and spot size of X-ray beams available at synchrotron facilities, support the possibility of using scanning-probe TSAXS/TWAXS to characterize heterogeneous structures at liquid surfaces.

  10. On the relationship between enamel band complexity and occlusal surface area in Equids (Mammalia, Perissodactyla

    Directory of Open Access Journals (Sweden)

    Nicholas A. Famoso

    2016-07-01

    Full Text Available Enamel patterns on the occlusal surfaces of equid teeth are asserted to have tribal-level differences. The most notable example compares the Equini and Hipparionini, where Equini have higher crowned teeth with less enamel-band complexity and less total occlusal enamel than Hipparionini. Whereas previous work has successfully quantified differences in enamel band shape by dividing the length of enamel band by the square root of the occlusal surface area (Occlusal Enamel Index, OEI, it was clear that OEI only partially removes the effect of body size. Because enamel band length scales allometrically, body size still has an influence on OEI, with larger individuals having relatively longer enamel bands than smaller individuals. Fractal dimensionality (D can be scaled to any level, so we have used it to quantify occlusal enamel complexity in a way that allows us to get at an accurate representation of the relationship between complexity and body size. To test the hypothesis of tribal-level complexity differences between Equini and Hipparionini, we digitally traced a sample of 98 teeth, one tooth per individual; 31 Hipparionini and 67 Equini. We restricted our sampling to the P3-M2 to reduce the effect of tooth position. After calculating the D of these teeth with the fractal box method which uses the number of boxes of various sizes to calculate the D of a line, we performed a t-test on the individual values of D for each specimen, comparing the means between the two tribes, and a phylogenetically informed generalized least squares regression (PGLS for each tribe with occlusal surface area as the independent variable and D as the dependent variable. The slopes of both PGLS analyses were compared using a t-test to determine if the same linear relationship existed between the two tribes. The t-test between tribes was significant (p < 0.0001, suggesting different D populations for each lineage. The PGLS for Hipparionini was a positive but not

  11. Verification Account Management System (VAMS)

    Data.gov (United States)

    Social Security Administration — The Verification Account Management System (VAMS) is the centralized location for maintaining SSA's verification and data exchange accounts. VAMS account management...

  12. Get a grip on chaos: Tailored measures for complex systems on surfaces

    Science.gov (United States)

    Firle, Sascha Oliver

    Complex systems are ubiquitous in physics, biology and mathematics. This thesis is concerned with describing and understanding complex systems. Some new concepts about how large systems can be viewed in a lower dimensional framework are proposed. The systems presented are examples from ecology and chemistry. In both cases we have a large amount of interacting units that can be understood by The predator-prey system investigated consists of ground beetles, Pterostichus cuprens L. (Coleoptera: Carabidae), that feeds on bird-cherry oat aphids. The beetles' movement can consistently be described by a combined model of surface diffusion and biased random walk. This allows conclusions about how fast and in which fashion the beetle covers its habitat. Movement is dependent on aphid densities and predation, in turn modifies aphid distributions locally. The presented generalized functional response theory describes predation rates in the presence of spatial heterogeneity. A single measure for fragmentation captures all essential features of the prey aggregation and allows the estimation of outbreak densities and distributions. The chemical example is the catalytic oxidation of CO on a Pt(110) single crystal surface. Unstable periodic orbits reconstructed from experimental data are used to reveal the topology of the attractor, underlying the time series dynamics. The found braid supports an orbit which implies that the time series is chaotic. The system is simulated numerically by a set of partial differential equations for surface coverage in one space dimension. The bifurcation diagram of the corresponding traveling wave ODE reveals the homoclinic and heteroclinic orbits that organize the phase space and mediate the transition to chaos. Studies in the PDE- framework relate this to the stability and to the interaction of pulse-like solutions.

  13. Spin crossover in Fe(phen)2(NCS)2 complexes on metallic surfaces

    Science.gov (United States)

    Gruber, Manuel; Miyamachi, Toshio; Davesne, Vincent; Bowen, Martin; Boukari, Samy; Wulfhekel, Wulf; Alouani, Mebarek; Beaurepaire, Eric

    2017-03-01

    In this review, we give an overview on the spin crossover of Fe(phen)2(NCS)2 complexes adsorbed on Cu(100), Cu2N/Cu(100), Cu(111), Co/Cu(111), Co(100), Au(100), and Au(111) surfaces. Depending on the strength of the interaction of the molecules with the substrates, the spin crossover behavior can be drastically changed. Molecules in direct contact with non-magnetic metallic surfaces coexist in both the high- and low-spin states but cannot be switched between the two. Our analysis shows that this is due to a strong interaction with the substrate in the form of a chemisorption that dictates the spin state of the molecules through its adsorption geometry. Upon reducing the interaction to the surface either by adding a second molecular layer or inserting an insulating thin film of Cu2N, the spin crossover behavior is restored and molecules can be switched between the two states with the help of scanning tunneling microscopy. Especially on Cu2N, the two states of single molecules are stable at low temperature and thus allow the realization of a molecular memory. Similarly, the molecules decoupled from metallic substrates in the second or higher layers display thermally driven spin crossover as has been revealed by X-ray absorption spectroscopy. Finally, we discuss the situation when the complex is brought into contact with a ferromagnetic substrate. This leads to a strong exchange coupling between the Fe spin in the high-spin state and the magnetization of the substrate as deduced from spin-polarized scanning tunneling spectroscopy and ab initio calculation.

  14. The interaction of streptococcal enolase with canine plasminogen: the role of surfaces in complex formation.

    Directory of Open Access Journals (Sweden)

    Vinod Balhara

    Full Text Available The enolase from Streptococcus pyogenes (Str enolase F137L/E363G is a homo-octamer shaped like a donut. Plasminogen (Pgn is a monomeric protein composed of seven discrete separated domains organized into a lock washer. The enolase is known to bind Pgn. In past work we searched for conditions in which the two proteins would bind to one another. The two native proteins in solution would not bind under any of the tried conditions. We found that if the structures were perturbed binding would occur. We stated that only the non-native Str enolase or Pgn would interact such that we could detect binding. We report here the results of a series of dual polarization interferometry (DPI experiments coupled with atomic force microscopy (AFM, isothermal titration calorimetry (ITC, dynamic light scattering (DLS, and fluorescence. We show that the critical condition for forming stable complexes of the two native proteins involves Str enolase binding to a surface. Surfaces that attract Str enolase are a sufficient condition for binding Pgn. Under certain conditions, Pgn adsorbed to a surface will bind Str enolase.

  15. New insights on the structure of the picloram-montmorillonite surface complexes.

    Science.gov (United States)

    Marco-Brown, Jose L; Trinelli, María Alcira; Gaigneaux, Eric M; Sánchez, Rosa M Torres; Afonso, María dos Santos

    2015-04-15

    The environmental mobility and bioavailability of Picloram (PCM) are determined by the amine and carboxylate chemical groups interaction with the soils mineral phases. Clay particles, such as montmorillonite (Mt), and the pH value of the media could play an important role in adsorption processes. Thus, the study of the role of soil components other than organic matter deserves further investigation for a more accurate assessment of the risk of groundwater contamination. Samples with PCM adsorbed on Mt dispersions were prepared at pH 3-9. Subsequently, the dispersions were separated, washed, centrifuged and stored at room temperature. Picloram (PCM) herbicide interaction with surface groups of montmorillonite (Mt) was studied using XRD, DTA, FTIR and XPS techniques. The entrance of PCM into the Mt basal space, in two different arrangements, perpendicular and planar, is proposed and the final arrangement depends on PCM concentration. The interaction of PCM with Mt surface sites through the nitrogen of the pyridine ring and carboxylic group of PCM, forming bidentate and bridge inner-sphere complexes was confirmed by FTIR and XPS analysis. The acidity constant of the PCM adsorbed on the Mt surface was calculated. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Surface complexation modeling of Cd(II) sorption to montmorillonite, bacteria, and their composite

    Science.gov (United States)

    Wang, Ning; Du, Huihui; Huang, Qiaoyun; Cai, Peng; Rong, Xingmin; Feng, Xionghan; Chen, Wenli

    2016-10-01

    Surface complexation modeling (SCM) has emerged as a powerful tool for simulating heavy metal adsorption processes on the surface of soil solid components under different geochemical conditions. The component additivity (CA) approach is one of the strategies that have been widely used in multicomponent systems. In this study, potentiometric titration, isothermal adsorption, zeta potential measurement, and extended X-ray absorption fine-structure (EXAFS) spectra analysis were conducted to investigate Cd adsorption on 2 : 1 clay mineral montmorillonite, on Gram-positive bacteria Bacillus subtilis, and their mineral-organic composite. We developed constant capacitance models of Cd adsorption on montmorillonite, bacterial cells, and mineral-organic composite. The adsorption behavior of Cd on the surface of the composite was well explained by CA-SCM. Some deviations were observed from the model simulations at pH SCM closely coincided with the estimated value of EXAFS at pH 6. The model could be useful for the prediction of heavy metal distribution at the interface of multicomponents and their risk evaluation in soils and associated environments.

  17. Approaches to surface complexation modeling of Uranium(VI) adsorption on aquifer sediments

    Science.gov (United States)

    Davis, J.A.; Meece, D.E.; Kohler, M.; Curtis, G.P.

    2004-01-01

    Uranium(VI) adsorption onto aquifer sediments was studied in batch experiments as a function of pH and U(VI) and dissolved carbonate concentrations in artificial groundwater solutions. The sediments were collected from an alluvial aquifer at a location upgradient of contamination from a former uranium mill operation at Naturita, Colorado (USA). The ranges of aqueous chemical conditions used in the U(VI) adsorption experiments (pH 6.9 to 7.9; U(VI) concentration 2.5 ?? 10-8 to 1 ?? 10-5 M; partial pressure of carbon dioxide gas 0.05 to 6.8%) were based on the spatial variation in chemical conditions observed in 1999-2000 in the Naturita alluvial aquifer. The major minerals in the sediments were quartz, feldspars, and calcite, with minor amounts of magnetite and clay minerals. Quartz grains commonly exhibited coatings that were greater than 10 nm in thickness and composed of an illite-smectite clay with occluded ferrihydrite and goethite nanoparticles. Chemical extractions of quartz grains removed from the sediments were used to estimate the masses of iron and aluminum present in the coatings. Various surface complexation modeling approaches were compared in terms of the ability to describe the U(VI) experimental data and the data requirements for model application to the sediments. Published models for U(VI) adsorption on reference minerals were applied to predict U(VI) adsorption based on assumptions about the sediment surface composition and physical properties (e.g., surface area and electrical double layer). Predictions from these models were highly variable, with results overpredicting or underpredicting the experimental data, depending on the assumptions used to apply the model. Although the models for reference minerals are supported by detailed experimental studies (and in ideal cases, surface spectroscopy), the results suggest that errors are caused in applying the models directly to the sediments by uncertain knowledge of: 1) the proportion and types of

  18. Contaminant Organic Complexes: Their Structure and Energetics in Surface Decontamination Processes

    International Nuclear Information System (INIS)

    Satish C. B. Myneni

    2005-01-01

    Siderophores are biological macromolecules (400-2000 Da) released by bacteria in iron limiting situations to sequester Fe from iron oxyhydroxides and silicates in the natural environment. These molecules contain hydroxamate and phenolate functional groups, and exhibit very high affinity for Fe 3+ . While several studies were conducted to understand the behavior of siderophores and their application to the metal sequestration and mineral dissolution, only a few of them have examined the molecular structure of siderophores and their interactions with metals and mineral surfaces in aqueous solutions. Improved understanding of the chemical state of different functional moieties in siderophores can assist in the application of these biological molecules in actinide separation, sequestration and decontamination processes. The focus of our research group is to evaluate the (a) functional group chemistry of selected siderophores and their metal complexes in aqueous solutions, and (b) the nature of siderophore interactions at the mineral-water interfaces. We selected desferrioxamine B (desB), a hydroxamate siderophore, and its small structural analogue, acetohydroxamic acid (aHa), for this investigation. We examined the functional group chemistry of these molecules as a function of pH, and their complexation with aqueous and solid phase Fe(III). For solid phase Fe, we synthesized all naturally occurring Fe(III)-oxyhydroxides (goethite, lepidocrocite, akaganeite, feroxyhite) and hematite. We also synthesized Fe-oxides (goethite and hematite) of different sizes to evaluate the influence of particle size on mineral dissolution kinetics. We used a series of molecular techniques to explore the functional group chemistry of these molecules and their complexes. Infrared spectroscopy is used to specifically identify the variations in oxime group as a function of pH and Fe(III) complexation. Resonance Raman spectroscopy was used to evaluate the nature of hydroxamate binding in the

  19. Characterization of a complex near-surface structure using well logging and passive seismic measurements

    Science.gov (United States)

    Benjumea, Beatriz; Macau, Albert; Gabàs, Anna; Figueras, Sara

    2016-04-01

    We combine geophysical well logging and passive seismic measurements to characterize the near-surface geology of an area located in Hontomin, Burgos (Spain). This area has some near-surface challenges for a geophysical study. The irregular topography is characterized by limestone outcrops and unconsolidated sediments areas. Additionally, the near-surface geology includes an upper layer of pure limestones overlying marly limestones and marls (Upper Cretaceous). These materials lie on top of Low Cretaceous siliciclastic sediments (sandstones, clays, gravels). In any case, a layer with reduced velocity is expected. The geophysical data sets used in this study include sonic and gamma-ray logs at two boreholes and passive seismic measurements: three arrays and 224 seismic stations for applying the horizontal-to-vertical amplitude spectra ratio method (H/V). Well-logging data define two significant changes in the P-wave-velocity log within the Upper Cretaceous layer and one more at the Upper to Lower Cretaceous contact. This technique has also been used for refining the geological interpretation. The passive seismic measurements provide a map of sediment thickness with a maximum of around 40 m and shear-wave velocity profiles from the array technique. A comparison between seismic velocity coming from well logging and array measurements defines the resolution limits of the passive seismic techniques and helps it to be interpreted. This study shows how these low-cost techniques can provide useful information about near-surface complexity that could be used for designing a geophysical field survey or for seismic processing steps such as statics or imaging.

  20. Prediction of iodide adsorption on oxides by surface complexation modeling with spectroscopic confirmation.

    Science.gov (United States)

    Nagata, Takahiro; Fukushi, Keisuke; Takahashi, Yoshio

    2009-04-15

    A deficiency in environmental iodine can cause a number of health problems. Understanding how iodine is sequestered by materials is helpful for evaluating and developing methods for minimizing human health effects related to iodine. In addition, (129)I is considered to be strategically important for safety assessment of underground radioactive waste disposal. To assess the long-term stability of disposed radioactive waste, an understanding of (129)I adsorption on geologic materials is essential. Therefore, the adsorption of I(-) on naturally occurring oxides is of environmental concern. The surface charges of hydrous ferric oxide (HFO) in NaI electrolyte solutions were measured by potentiometric acid-base titration. The surface charge data were analyzed by means of an extended triple-layer model (ETLM) for surface complexation modeling to obtain the I(-) adsorption reaction and its equilibrium constant. The adsorption of I(-) was determined to be an outer-sphere process from ETLM analysis, which was consistent with independent X-ray absorption near-edge structure (XANES) observation of I(-) adsorbed on HFO. The adsorption equilibrium constants for I(-) on beta-TiO(2) and gamma-Al(2)O(3) were also evaluated by analyzing the surface charge data of these oxides in NaI solution as reported in the literature. Comparison of these adsorption equilibrium constants for HFO, beta-TiO(2), and gamma-Al(2)O(3) based on site-occupancy standard states permitted prediction of I(-) adsorption equilibrium constants for all oxides by means of the Born solvation theory. The batch adsorption data for I(-) on HFO and amorphous aluminum oxide were reasonably reproduced by ETLM with the predicted equilibrium constants, confirming the validity of the present approach. Using the predicted adsorption equilibrium constants, we calculated distribution coefficient (K(d)) values for I(-) adsorption on common soil minerals as a function of pH and ionic strength.

  1. Experimental inventory verification system

    International Nuclear Information System (INIS)

    Steverson, C.A.; Angerman, M.I.

    1991-01-01

    As Low As Reasonably Achievable (ALARA) goals and Department of Energy (DOE) inventory requirements are frequently in conflict at facilities across the DOE complex. The authors wish, on one hand, to verify the presence of correct amounts of nuclear materials that are in storage or in process; yet on the other hand, we wish to achieve ALARA goals by keeping individual and collective exposures as low as social, technical, economic, practical, and public policy considerations permit. The Experimental Inventory Verification System (EIVSystem) is a computer-based, camera-driven system that utilizes image processing technology to detect change in vault areas. Currently in the test and evaluation phase at Idaho National Engineering Laboratory, this system guards personnel. The EIVSystem continually monitors the vault, providing proof of changed status for objects sorted within the vault. This paper reports that these data could provide the basis for reducing inventory requirements when no change has occurred, thus helping implement ALARA policy; the data will also help describe there target area of an inventory when change has been shown to occur

  2. An evaluation of WRF's ability to reproduce the surface wind over complex terrain based on typical circulation patterns.

    NARCIS (Netherlands)

    Jiménez, P.A.; Dudhia, J.; González-Rouco, J.F.; Montávez, J.P.; Garcia-Bustamante, E.; Navarro, J.; Vilà-Guerau de Arellano, J.; Munoz-Roldán, A.

    2013-01-01

    [1] The performance of the Weather Research and Forecasting (WRF) model to reproduce the surface wind circulations over complex terrain is examined. The atmospheric evolution is simulated using two versions of the WRF model during an over 13¿year period (1992 to 2005) over a complex terrain region

  3. Surface rheological properties of liquid-liquid interfaces stabilized by protein fibrillar aggregates and protein-polysaccharide complexes

    NARCIS (Netherlands)

    Humblet-Hua, K.N.P.; Linden, van der E.; Sagis, L.M.C.

    2013-01-01

    In this study we have investigated the surface rheological properties of oil-water interfaces stabilized by fibrils from lysozyme (long and semi-flexible and short and rigid ones), fibrils from ovalbumin (short and semi-flexible), lysozyme-pectin complexes, or ovalbumin-pectin complexes. We have

  4. FMCT verification: Case studies

    International Nuclear Information System (INIS)

    Hui Zhang

    2001-01-01

    Full text: How to manage the trade-off between the need for transparency and the concern about the disclosure of sensitive information would be a key issue during the negotiations of FMCT verification provision. This paper will explore the general concerns on FMCT verification; and demonstrate what verification measures might be applied to those reprocessing and enrichment plants. A primary goal of an FMCT will be to have the five declared nuclear weapon states and the three that operate unsafeguarded nuclear facilities become parties. One focus in negotiating the FMCT will be verification. Appropriate verification measures should be applied in each case. Most importantly, FMCT verification would focus, in the first instance, on these states' fissile material production facilities. After the FMCT enters into force, all these facilities should be declared. Some would continue operating to produce civil nuclear power or to produce fissile material for non- explosive military uses. The verification measures necessary for these operating facilities would be essentially IAEA safeguards, as currently being applied to non-nuclear weapon states under the NPT. However, some production facilities would be declared and shut down. Thus, one important task of the FMCT verifications will be to confirm the status of these closed facilities. As case studies, this paper will focus on the verification of those shutdown facilities. The FMCT verification system for former military facilities would have to differ in some ways from traditional IAEA safeguards. For example, there could be concerns about the potential loss of sensitive information at these facilities or at collocated facilities. Eventually, some safeguards measures such as environmental sampling might be seen as too intrusive. Thus, effective but less intrusive verification measures may be needed. Some sensitive nuclear facilities would be subject for the first time to international inspections, which could raise concerns

  5. To address surface reaction network complexity using scaling relations machine learning and DFT calculations

    International Nuclear Information System (INIS)

    Ulissi, Zachary W.; Medford, Andrew J.; Bligaard, Thomas; Nørskov, Jens K.

    2017-01-01

    Surface reaction networks involving hydrocarbons exhibit enormous complexity with thousands of species and reactions for all but the very simplest of chemistries. We present a framework for optimization under uncertainty for heterogeneous catalysis reaction networks using surrogate models that are trained on the fly. The surrogate model is constructed by teaching a Gaussian process adsorption energies based on group additivity fingerprints, combined with transition-state scaling relations and a simple classifier for determining the rate-limiting step. The surrogate model is iteratively used to predict the most important reaction step to be calculated explicitly with computationally demanding electronic structure theory. Applying these methods to the reaction of syngas on rhodium(111), we identify the most likely reaction mechanism. Lastly, propagating uncertainty throughout this process yields the likelihood that the final mechanism is complete given measurements on only a subset of the entire network and uncertainty in the underlying density functional theory calculations.

  6. Areal Measurements of Ozone, Water, and Heat Fluxes Over Land With Different Surface Complexity, Using Aircraft

    International Nuclear Information System (INIS)

    Hicks, Bruce B.

    2001-01-01

    Contemporary models addressing issues of air quality and/or atmospheric deposition continue to exploit air-surface exchange formulations originating from single-tower studies. In reality,these expressions describe situations that are rare in the real world - nearly flat and spatially homogeneous. There have been several theoretical suggestions about how to extend from single-point understanding to areal descriptions, but so far the capability to address the problem experimentally has been limited. In recent years, however, developments in sensing technology have permitted adaptation of eddy-correlation methods to low-flying aircraft in a far more cost-effective manner than previously. A series of field experiments has been conducted, ranging from flat farmland to rolling countryside, employing a recently modified research aircraft operated by the US NationalOceanic and Atmospheric Administration (NOAA). The results demonstrate the complexity of the spatial heterogeneity question,especially for pollutants (ozone in particular). In general, the uncertainty associated with the adoption of any single-point formulation when describing areal averages is likely to be in the range 10% to 40%. In the case of sensible and latent heat fluxes, the overall behavior is controlled by the amount of energy available. For pollutant deposition, there is no constraint equivalent to the net radiation limitation on convective heat exchange. Consequently, dry deposition rates and air-surface exchange of trace gases in general are especially vulnerable to errors in spatial extrapolation. The results indicate that the susceptibility of dry deposition formulations to terrain complexity depends on the deposition velocity itself. For readily transferred pollutants (such as HNO 3 ), a factor of two error could be involved

  7. Modeling uranium(VI) adsorption onto montmorillonite under varying carbonate concentrations: A surface complexation model accounting for the spillover effect on surface potential

    Science.gov (United States)

    Tournassat, C.; Tinnacher, R. M.; Grangeon, S.; Davis, J. A.

    2018-01-01

    The prediction of U(VI) adsorption onto montmorillonite clay is confounded by the complexities of: (1) the montmorillonite structure in terms of adsorption sites on basal and edge surfaces, and the complex interactions between the electrical double layers at these surfaces, and (2) U(VI) solution speciation, which can include cationic, anionic and neutral species. Previous U(VI)-montmorillonite adsorption and modeling studies have typically expanded classical surface complexation modeling approaches, initially developed for simple oxides, to include both cation exchange and surface complexation reactions. However, previous models have not taken into account the unique characteristics of electrostatic surface potentials that occur at montmorillonite edge sites, where the electrostatic surface potential of basal plane cation exchange sites influences the surface potential of neighboring edge sites ('spillover' effect). A series of U(VI) - Na-montmorillonite batch adsorption experiments was conducted as a function of pH, with variable U(VI), Ca, and dissolved carbonate concentrations. Based on the experimental data, a new type of surface complexation model (SCM) was developed for montmorillonite, that specifically accounts for the spillover effect using the edge surface speciation model by Tournassat et al. (2016a). The SCM allows for a prediction of U(VI) adsorption under varying chemical conditions with a minimum number of fitting parameters, not only for our own experimental results, but also for a number of published data sets. The model agreed well with many of these datasets without introducing a second site type or including the formation of ternary U(VI)-carbonato surface complexes. The model predictions were greatly impacted by utilizing analytical measurements of dissolved inorganic carbon (DIC) concentrations in individual sample solutions rather than assuming solution equilibration with a specific partial pressure of CO2, even when the gas phase was

  8. Diazonium salt derivatives of osmium bipyridine complexes: Electrochemical grafting and characterisation of modified surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Garrett, David J. [MacDiarmid Institute for Advanced Materials and Nanotechnology, Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch (New Zealand); Jenkins, Peter [School of Chemistry, National University of Ireland, Galway (Ireland); Polson, Matthew I.J. [Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch (New Zealand); Leech, Donal [School of Chemistry, National University of Ireland, Galway (Ireland); Baronian, Keith H.R. [School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch (New Zealand); Downard, Alison J., E-mail: alison.downard@canterbury.ac.n [MacDiarmid Institute for Advanced Materials and Nanotechnology, Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch (New Zealand)

    2011-02-01

    Osmium bipyridine complexes were directly grafted to carbon electrodes through electroreduction of the diazonium salts [Os(bpy-ph-N{sub 2}{sup +}){sub 3}](PF{sub 6}){sub 5} (1) and [Os(bpy-ph-N{sub 2}{sup +}){sub 2}Cl{sub 2}](PF{sub 6}){sub 2} (2). Growth of the films was not self-limiting as is usually found for grafting from diazonium salts. It appears that electron hopping through the bipyridine ligands of the immobilised complexes enables film growth to continue at a constant rate during grafting by potential cycling. The surface concentrations of deposited films were measured electrochemically and the film thicknesses were measured by depth-profiling using the atomic force microscope. Films up to 42 nm thick were prepared with no evidence for slowing of film growth. The grafted films exhibited high stability when repetitively cycled through the Os{sup 2+/3+} couple and electron transfer rate constants of 11.4 s{sup -1} and 35.4 s{sup -1} were measured in ACN and PBS, respectively, for the Os{sup 2+/3+} couple of the film grafted from 1.

  9. Diazonium salt derivatives of osmium bipyridine complexes: Electrochemical grafting and characterisation of modified surfaces

    International Nuclear Information System (INIS)

    Garrett, David J.; Jenkins, Peter; Polson, Matthew I.J.; Leech, Donal; Baronian, Keith H.R.; Downard, Alison J.

    2011-01-01

    Osmium bipyridine complexes were directly grafted to carbon electrodes through electroreduction of the diazonium salts [Os(bpy-ph-N 2 + ) 3 ](PF 6 ) 5 (1) and [Os(bpy-ph-N 2 + ) 2 Cl 2 ](PF 6 ) 2 (2). Growth of the films was not self-limiting as is usually found for grafting from diazonium salts. It appears that electron hopping through the bipyridine ligands of the immobilised complexes enables film growth to continue at a constant rate during grafting by potential cycling. The surface concentrations of deposited films were measured electrochemically and the film thicknesses were measured by depth-profiling using the atomic force microscope. Films up to 42 nm thick were prepared with no evidence for slowing of film growth. The grafted films exhibited high stability when repetitively cycled through the Os 2+/3+ couple and electron transfer rate constants of 11.4 s -1 and 35.4 s -1 were measured in ACN and PBS, respectively, for the Os 2+/3+ couple of the film grafted from 1.

  10. Using Google Earth Surface Metrics to Predict Plant Species Richness in a Complex Landscape

    Directory of Open Access Journals (Sweden)

    Sebastián Block

    2016-10-01

    Full Text Available Google Earth provides a freely available, global mosaic of high-resolution imagery from different sensors that has become popular in environmental and ecological studies. However, such imagery lacks the near-infrared band often used in studying vegetation, thus its potential for estimating vegetation properties remains unclear. In this study, we assess the potential of Google Earth imagery to describe and predict vegetation attributes. Further, we compare it to the potential of SPOT imagery, which has additional spectral information. We measured basal area, vegetation height, crown cover, density of individuals, and species richness in 60 plots in the oak forests of a complex volcanic landscape in central Mexico. We modelled each vegetation attribute as a function of surface metrics derived from Google Earth and SPOT images, and selected the best-supported linear models from each source. Total species richness was the best-described and predicted variable: the best Google Earth-based model explained nearly as much variation in species richness as its SPOT counterpart (R2 = 0.44 and 0.51, respectively. However, Google Earth metrics emerged as poor predictors of all remaining vegetation attributes, whilst SPOT metrics showed potential for predicting vegetation height. We conclude that Google Earth imagery can be used to estimate species richness in complex landscapes. As it is freely available, Google Earth can broaden the use of remote sensing by researchers and managers in low-income tropical countries where most biodiversity hotspots are found.

  11. B lymphocytes confer immune tolerance via cell surface GARP-TGF-β complex.

    Science.gov (United States)

    Wallace, Caroline H; Wu, Bill X; Salem, Mohammad; Ansa-Addo, Ephraim A; Metelli, Alessandra; Sun, Shaoli; Gilkeson, Gary; Shlomchik, Mark J; Liu, Bei; Li, Zihai

    2018-04-05

    GARP, a cell surface docking receptor for binding and activating latent TGF-β, is highly expressed by platelets and activated Tregs. While GARP is implicated in immune invasion in cancer, the roles of the GARP-TGF-β axis in systemic autoimmune diseases are unknown. Although B cells do not express GARP at baseline, we found that the GARP-TGF-β complex is induced on activated human and mouse B cells by ligands for multiple TLRs, including TLR4, TLR7, and TLR9. GARP overexpression on B cells inhibited their proliferation, induced IgA class-switching, and dampened T cell-independent antibody production. In contrast, B cell-specific deletion of GARP-encoding gene Lrrc32 in mice led to development of systemic autoimmune diseases spontaneously as well as worsening of pristane-induced lupus-like disease. Canonical TGF-β signaling more readily upregulates GARP in Peyer patch B cells than in splenic B cells. Furthermore, we demonstrated that B cells are required for the induction of oral tolerance of T cell-dependent antigens via GARP. Our studies reveal for the first time to our knowledge that cell surface GARP-TGF-β is an important checkpoint for regulating B cell peripheral tolerance, highlighting a mechanism of autoimmune disease pathogenesis.

  12. Dynamics of Defects and Dopants in Complex Systems: Si and Oxide Surfaces and Interfaces

    Science.gov (United States)

    Kirichenko, Taras; Yu, Decai; Banarjee, Sanjay; Hwang, Gyeong

    2004-10-01

    Fabrication of forthcoming nanometer scale electronic devices faces many difficulties including formation of extremely shallow and highly doped junctions. At present, ultra-low-energy ion implantation followed by high-temperature thermal annealing is most widely used to fabricate such ultra-shallow junctions. In the process, a great challenge lies in achieving precise control of redistribution and electrical activation of dopant impurities. Native defects (such as vacancies and interstitials) generated during implantation are known to be mainly responsible for the TED and also influence significantly the electrical activation/deactivation. Defect-dopant dynamics is rather well understood in crystalline Si and SiO2. However, little is known about their diffusion and annihilation (or precipitation) at the surfaces and interfaces, despite its growing importance in determining junction profiles as device dimensions get smaller. In this talk, we will present our density functional theory calculation results on the atomic and electronic structure and dynamical behavior of native defects and dopant-defect complexes in disordered/strained Si and oxide systems, such as i) clean and absorbent-modified Si(100) surface and subsurface layers, ii) amorphous-crystalline Si interfaces and iii) amorphous SiO2/Si interfaces. The fundamental understanding and data is essential in developing a comprehensive kinetic model for junction formation, which would contribute greatly in improving current process technologies.

  13. Nitric oxide reduction in coal combustion: role of char surface complexes in heterogeneous reactions

    Energy Technology Data Exchange (ETDEWEB)

    Arenillas, A.; Rubiera, F.; Pis, J.J. [Instituto Nacional del Carbon, CSIC, Oviedo (Spain)

    2002-12-15

    Nitrogen oxides are one of the major environmental problems arising from fossil fuel combustion. Coal char is relatively rich in nitrogen, and so this is an important source of nitrogen oxides during coal combustion. However, due to its carbonaceous nature, char can also reduce NO through heterogeneous reduction. The objectives of this work were on one hand to compare NO emissions from coal combustion in two different types of equipment and on the other hand to study the influence of char surface chemistry on NO reduction. A series of combustion tests were carried out in two different scale devices: a thermogravimetric analyzer coupled to a mass spectrometer and an FTIR (TG-MS-FTIR) and a fluidized bed reactor with on-line battery of analyzers. According to the results obtained, it can be said that the TG-MS-FTIR system provides valuable information about NO heterogeneous reduction and it can give good trends of the behaviour in other combustion equipments, i.e. fluidized bed combustors. It has been also pointed out that NO-char interaction depends to a large extent on temperature. In the low-temperature range NO heterogeneous reduction seems to be controlled by the evolution of surface complexes. In the high-temperature range a different mechanism is involved in NO heterogeneous reduction, the nature of the carbon matrix being a key factor. 27 refs., 6 figs., 1 tab.

  14. Formal Verification of Circuits and Systems

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    The problem of validation and verification of correctness of present day hardware and soft- ware systems has become extemely complex due to the enormous growth in the size of the designs. Today typically 50% to 70% of the design cycle time is spent in verifying correct- ness. While simulation remains a predominant form ...

  15. Engineering yeast consortia for surface-display of complex cellulosome structures

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Wilfred [University of Delaware

    2014-03-31

    As our society marches toward a more technologically advanced future, energy and environmental sustainability are some of the most challenging problems we face today. Biomass is one of the most abundant renewable-feedstock for sustainable production of biofuels. However, the main technological obstacle to more widespread uses of this resource is the lack of low-cost technologies to overcome the recalcitrant nature of the cellulosic structure, especially the hydrolysis step on highly ordered celluloses. In this proposal, we successfully engineered several efficient and inexpensive whole-cell biocatalysts in an effort to produce economically compatible and sustainable biofuels, namely cellulosic ethanol. Our approach was to display of a highly efficient cellulolytic enzyme complex, named cellulosome, on the surface of a historical ethanol producer Saccharomyces cerevisiae for the simultaneous and synergistic saccharification and fermentation of cellulose to ethanol. We first demonstrated the feasibility of assembling a mini-cellulosome by incubating E. coli lysates expressing three different cellulases. Resting cells displaying mini-cellulosomes produced 4-fold more ethanol from phosphoric acid-swollen cellulose (PASC) than cultures with only added enzymes. The flexibility to assemble the mini-cellulosome structure was further demonstrated using a synthetic yeast consortium through intracellular complementation. Direct ethanol production from PASC was demonstrated with resting cell cultures. To create a microorganism suitable for a more cost-effective process, called consolidated bioprocessing (CBP), a synthetic consortium capable of displaying mini-cellulosomes on the cell surface via intercellular complementation was created. To further improve the efficiency, a new adaptive strategy of employing anchoring and adaptor scaffoldins to amplify the number of enzymatic subunits was developed, resulting in the creation of an artificial tetravalent cellulosome on the

  16. Optimization of Al-CVD process based on elementary reaction simulation and experimental verification: From the growth rate to the surface morphology

    International Nuclear Information System (INIS)

    Sugiyama, Masakazu; Iino, Tomohisa; Nakajima, Tohru; Tanaka, Takeshi; Egashira, Yasuyuki; Yamashita, Kohichi; Komiyama, Hiroshi; Shimogaki, Yukihiro

    2006-01-01

    We propose a method to reduce the surface roughness of Al film in the chemical vapor deposition (CVD) using dimethyl-aluminum-hydride (DMAH) as the precursor. An elementary reaction simulation was executed not only to predict the deposition rate but also to predict the coverage of the film by surface adsorbates. It was assumed that high surface coverage is essential in order to deposit smooth films because the adsorbates protect the surface from oxidation which causes discontinuous growth of crystal grains. According to this principle, the condition, that realizes both high surface coverage and high deposition rate at the same time by using the elementary reaction simulation, was sought. A nozzle inlet was used instead of a conventional showerhead. This drastically improved the surface morphology, showing the effectiveness of this theoretical optimization procedure

  17. Nuclear test ban verification

    International Nuclear Information System (INIS)

    Chun, Kin-Yip

    1991-07-01

    This report describes verification and its rationale, the basic tasks of seismic verification, the physical basis for earthquake/explosion source discrimination and explosion yield determination, the technical problems pertaining to seismic monitoring of underground nuclear tests, the basic problem-solving strategy deployed by the forensic seismology resarch team at the University of Toronto, and the scientific significance of the team's research. The research carried out at the Univeristy of Toronto has two components: teleseismic verification using P wave recordings from the Yellowknife Seismic Array (YKA), and regional (close-in) verification using high-frequency L g and P n recordings from the Eastern Canada Telemetered Network. Major differences have been found in P was attenuation among the propagation paths connecting the YKA listening post with seven active nuclear explosion testing areas in the world. Significant revisions have been made to previously published P wave attenuation results, leading to more interpretable nuclear explosion source functions. (11 refs., 12 figs.)

  18. Standard Verification System (SVS)

    Data.gov (United States)

    Social Security Administration — SVS is a mainframe program that accesses the NUMIDENT to perform SSN verifications. This program is called by SSA Internal applications to verify SSNs. There is also...

  19. Formal Verification -26 ...

    Indian Academy of Sciences (India)

    by testing of the components and successful testing leads to the software being ... Formal verification is based on formal methods which are mathematically based ..... scenario under which a similar error could occur. There are various other ...

  20. SSN Verification Service

    Data.gov (United States)

    Social Security Administration — The SSN Verification Service is used by Java applications to execute the GUVERF02 service using the WebSphere/CICS Interface. It accepts several input data fields...

  1. Environmental technology verification methods

    CSIR Research Space (South Africa)

    Szewczuk, S

    2016-03-01

    Full Text Available Environmental Technology Verification (ETV) is a tool that has been developed in the United States of America, Europe and many other countries around the world to help innovative environmental technologies reach the market. Claims about...

  2. Verification of RADTRAN

    International Nuclear Information System (INIS)

    Kanipe, F.L.; Neuhauser, K.S.

    1995-01-01

    This document presents details of the verification process of the RADTRAN computer code which was established for the calculation of risk estimates for radioactive materials transportation by highway, rail, air, and waterborne modes

  3. An AP endonuclease 1-DNA polymerase beta complex: theoretical prediction of interacting surfaces.

    Directory of Open Access Journals (Sweden)

    Alexej Abyzov

    2008-04-01

    Full Text Available Abasic (AP sites in DNA arise through both endogenous and exogenous mechanisms. Since AP sites can prevent replication and transcription, the cell contains systems for their identification and repair. AP endonuclease (APEX1 cleaves the phosphodiester backbone 5' to the AP site. The cleavage, a key step in the base excision repair pathway, is followed by nucleotide insertion and removal of the downstream deoxyribose moiety, performed most often by DNA polymerase beta (pol-beta. While yeast two-hybrid studies and electrophoretic mobility shift assays provide evidence for interaction of APEX1 and pol-beta, the specifics remain obscure. We describe a theoretical study designed to predict detailed interacting surfaces between APEX1 and pol-beta based on published co-crystal structures of each enzyme bound to DNA. Several potentially interacting complexes were identified by sliding the protein molecules along DNA: two with pol-beta located downstream of APEX1 (3' to the damaged site and three with pol-beta located upstream of APEX1 (5' to the damaged site. Molecular dynamics (MD simulations, ensuring geometrical complementarity of interfaces, enabled us to predict interacting residues and calculate binding energies, which in two cases were sufficient (approximately -10.0 kcal/mol to form a stable complex and in one case a weakly interacting complex. Analysis of interface behavior during MD simulation and visual inspection of interfaces allowed us to conclude that complexes with pol-beta at the 3'-side of APEX1 are those most likely to occur in vivo. Additional multiple sequence analyses of APEX1 and pol-beta in related organisms identified a set of correlated mutations of specific residues at the predicted interfaces. Based on these results, we propose that pol-beta in the open or closed conformation interacts and makes a stable interface with APEX1 bound to a cleaved abasic site on the 3' side. The method described here can be used for analysis in

  4. Using AFM to probe the complexation of DNA with anionic lipids mediated by Ca(2+): the role of surface pressure.

    Science.gov (United States)

    Luque-Caballero, Germán; Martín-Molina, Alberto; Sánchez-Treviño, Alda Yadira; Rodríguez-Valverde, Miguel A; Cabrerizo-Vílchez, Miguel A; Maldonado-Valderrama, Julia

    2014-04-28

    Complexation of DNA with lipids is currently being developed as an alternative to classical vectors based on viruses. Most of the research to date focuses on cationic lipids owing to their spontaneous complexation with DNA. Nonetheless, recent investigations have revealed that cationic lipids induce a large number of adverse effects on DNA delivery. Precisely, the lower cytotoxicity of anionic lipids accounts for their use as a promising alternative. However, the complexation of DNA with anionic lipids (mediated by cations) is still in early stages and is not yet well understood. In order to explore the molecular mechanisms underlying the complexation of anionic lipids and DNA we proposed a combined methodology based on the surface pressure-area isotherms, Gibbs elasticity and Atomic Force Microscopy (AFM). These techniques allow elucidation of the role of the surface pressure in the complexation and visualization of the interfacial aggregates for the first time. We demonstrate that the DNA complexes with negatively charged model monolayers (DPPC/DPPS 4 : 1) only in the presence of Ca(2+), but is expelled at very high surface pressures. Also, according to the Gibbs elasticity plot, the complexation of lipids and DNA implies a whole fluidisation of the monolayer and a completely different phase transition map in the presence of DNA and Ca(2+). AFM imaging allows identification for the first time of specific morphologies associated with different packing densities. At low surface coverage, a branched net like structure is observed whereas at high surface pressure fibers formed of interfacial aggregates appear. In summary, Ca(2+) mediates the interaction between DNA and negatively charged lipids and also the conformation of the ternary system depends on the surface pressure. Such observations are important new generic features of the interaction between DNA and anionic lipids.

  5. Analysis of gold(I/III)-complexes by HPLC-ICP-MS demonstrates gold(III) stability in surface waters.

    Science.gov (United States)

    Ta, Christine; Reith, Frank; Brugger, Joël; Pring, Allan; Lenehan, Claire E

    2014-05-20

    Understanding the form in which gold is transported in surface- and groundwaters underpins our understanding of gold dispersion and (bio)geochemical cycling. Yet, to date, there are no direct techniques capable of identifying the oxidation state and complexation of gold in natural waters. We present a reversed phase ion-pairing HPLC-ICP-MS method for the separation and determination of aqueous gold(III)-chloro-hydroxyl, gold(III)-bromo-hydroxyl, gold(I)-thiosulfate, and gold(I)-cyanide complexes. Detection limits for the gold species range from 0.05 to 0.30 μg L(-1). The [Au(CN)2](-) gold cyanide complex was detected in five of six waters from tailings and adjacent monitoring bores of working gold mines. Contrary to thermodynamic predictions, evidence was obtained for the existence of Au(III)-complexes in circumneutral, hypersaline waters of a natural lake overlying a gold deposit in Western Australia. This first direct evidence for the existence and stability of Au(III)-complexes in natural surface waters suggests that Au(III)-complexes may be important for the transport and biogeochemical cycling of gold in surface environments. Overall, these results show that near-μg L(-1) enrichments of Au in environmental waters result from metastable ligands (e.g., CN(-)) as well as kinetically controlled redox processes leading to the stability of highly soluble Au(III)-complexes.

  6. Mathematical Optimal Sequence Model Development to Process Planes and Other Interconnected Surfaces of Complex Body Parts

    Directory of Open Access Journals (Sweden)

    I. I. Kravchenko

    2016-01-01

    Full Text Available Experience in application of multi-operational machines CNC (MOM CNC shows that they are efficient only in case of significantly increasing productivity and dramatically reducing time-to-market cycle of new products. Most full technological MOM capabilities are revealed when processing the complex body parts. The more complex is a part design and the more is its number of machined surfaces, the more tools are necessary for its processing and positioning, the more is an efficiency of their application. At the same time, the case history of using these machines in industry shows that MOM CNC are, virtually, used mostly for technological processes of universal equipment, which is absolutely unacceptable. One way to improve the processing performance on MOM CNC is to reduce nonproductive machine time through reducing the mutual idle movements of the working machine. This problem is solved using dynamic programming methods, one of which is the solution of the traveling salesman problem (Bellman's method. With a known plan for treatment of all elementary surfaces of the body part, i.e. the known number of performed transitions, each transition is represented as a vertex of some graph, while technological links between the vertices are its edges. A mathematical model is developed on the Bellman principle, which is adapted to technological tasks to minimize the idle time of mutual idle movements of the working machine to perform all transitions in the optimal sequence. The initial data to fill matrix of time expenditures are time consumed by the hardware after executing the i-th transition, and necessary to complete the j-transition. The programmer fills in matrix cells according to known routing body part taking into account the time for part and table positioning, tool exchange, spindle and table approach to the working zone, and the time of table rotation, etc. The mathematical model was tested when machining the body part with 36 transitions on the

  7. Determination of B-complex vitamins in pharmaceutical formulations by surface-enhanced Raman spectroscopy

    Science.gov (United States)

    Junior, Benedito Roberto Alvarenga; Soares, Frederico Luis Felipe; Ardila, Jorge Armando; Durango, Luis Guillermo Cuadrado; Forim, Moacir Rossi; Carneiro, Renato Lajarim

    2018-01-01

    The aim of this work was to quantify B-complex vitamins in pharmaceutical samples by surface enhanced Raman spectroscopy technique using gold colloid substrate. Synthesis of gold nanoparticles was performed according to an adapted Turkevich method. Initial essays were able to suggest the orientation of molecules on gold nanoparticles surface. Central Composite design was performed to obtain the highest SERS signal for nicotinamide and riboflavin. The evaluated parameters in the experimental design were volume of AuNPs, concentration of vitamins and sodium chloride concentration. The best condition for nicotinamide was NaCl 2.3 × 10- 3 mol L- 1 and 700 μL of AuNPs colloid and this same condition showed to be adequate to quantify thiamine. The experimental design for riboflavin shows the best condition at NaCl 1.15 × 10- 2 mol L- 1 and 2.8 mL of AuNPs colloid. It was possible to quantify thiamine and nicotinamide in presence of others vitamins and excipients in two solid multivitamin formulations using the standard addition procedure. The standard addition curve presented a R2 higher than 0.96 for both nicotinamide and thiamine, at orders of magnitude 10- 7 and 10- 8 mol L- 1, respectively. The nicotinamide content in a cosmetic gel sample was also quantified by direct analysis presenting R2 0.98. The t-student test presented no significant difference regarding HPLC method. Despite the experimental design performed for riboflavin, it was not possible its quantification in the commercial samples.

  8. Hydrous ferric oxide: evaluation of Cd-HFO surface complexation models combining Cd(K) EXAFS data, potentiometric titration results, and surface site structures identified from mineralogical knowledge.

    Science.gov (United States)

    Spadini, Lorenzo; Schindler, Paul W; Charlet, Laurent; Manceau, Alain; Vala Ragnarsdottir, K

    2003-10-01

    The surface properties of ferrihydrite were studied by combining wet chemical data, Cd(K) EXAFS data, and a surface structure and protonation model of the ferrihydrite surface. Acid-base titration experiments and Cd(II)-ferrihydrite sorption experiments were performed within 3titration data could be adequately modeled by triple bond Fe- OH(2)(+1/2)-H(+)triple bond Fe-OH(-1/2),logk((int))=-8.29, assuming the existence of a unique intrinsic microscopic constant, logk((int)), and consequently the existence of a single significant type of acid-base reactive functional groups. The surface structure model indicates that these groups are terminal water groups. The Cd(II) data were modeled assuming the existence of a single reactive site. The model fits the data set at low Cd(II) concentration and up to 50% surface coverage. At high coverage more Cd(II) ions than predicted are adsorbed, which is indicative of the existence of a second type of site of lower affinity. This agrees with the surface structure and protonation model developed, which indicates comparable concentrations of high- and low-affinity sites. The model further shows that for each class of low- and high-affinity sites there exists a variety of corresponding Cd surface complex structure, depending on the model crystal faces on which the complexes develop. Generally, high-affinity surface structures have surface coordinations of 3 and 4, as compared to 1 and 2 for low-affinity surface structures.

  9. Noncontact Surface Roughness Estimation Using 2D Complex Wavelet Enhanced ResNet for Intelligent Evaluation of Milled Metal Surface Quality

    Directory of Open Access Journals (Sweden)

    Weifang Sun

    2018-03-01

    Full Text Available Machined surfaces are rough from a microscopic perspective no matter how finely they are finished. Surface roughness is an important factor to consider during production quality control. Using modern techniques, surface roughness measurements are beneficial for improving machining quality. With optical imaging of machined surfaces as input, a convolutional neural network (CNN can be utilized as an effective way to characterize hierarchical features without prior knowledge. In this paper, a novel method based on CNN is proposed for making intelligent surface roughness identifications. The technical scheme incorporates there elements: texture skew correction, image filtering, and intelligent neural network learning. Firstly, a texture skew correction algorithm, based on an improved Sobel operator and Hough transform, is applied such that surface texture directions can be adjusted. Secondly, two-dimensional (2D dual tree complex wavelet transform (DTCWT is employed to retrieve surface topology information, which is more effective for feature classifications. In addition, residual network (ResNet is utilized to ensure automatic recognition of the filtered texture features. The proposed method has verified its feasibility as well as its effectiveness in actual surface roughness estimation experiments using the material of spheroidal graphite cast iron 500-7 in an agricultural machinery manufacturing company. Testing results demonstrate the proposed method has achieved high-precision surface roughness estimation.

  10. Surface complexation modelling: Experiments on the sorption of nickel on quartz

    International Nuclear Information System (INIS)

    Puukko, E.; Hakanen, M.

    1995-10-01

    Assessing the safety of a final repository for nuclear wastes requires knowledge concerning the way in which the radionuclides released are retarded in the geosphere. The aim of the work is to aquire knowledge of empirical methods repeating the experiments on the sorption of nickel on quartz described in the reports published by the British Geological Survey (BGS). The experimental results were modelled with computer models at the Technical Research Centre of Finland (VTT Chemical Technology). The results showed that the experimental knowledge of the sorption of Ni on quartz have been acheved by repeating the experiments of BGS. Experiments made with the two quartz types, Min-U-Sil 5 (MUS) and Nilsiae, showed the difference in sorption of Ni in the low ionic strength solution (0.001 M NaNO 3 ). The sorption of Ni on MUS was higher than predicted by the Surface Complexation Model (SCM). The phenomenon was also observed by the BGS, and may be due to the different amounts of inpurities in the MUS and in the NLS. In other respects, the results of the sorption experiments fitted quite well with those predicted by the SCM model. (8 refs., 8 figs., 11 tabs.)

  11. Direct protein quantification in complex sample solutions by surface-engineered nanorod probes

    KAUST Repository

    Schrittwieser, Stefan

    2017-06-30

    Detecting biomarkers from complex sample solutions is the key objective of molecular diagnostics. Being able to do so in a simple approach that does not require laborious sample preparation, sophisticated equipment and trained staff is vital for point-of-care applications. Here, we report on the specific detection of the breast cancer biomarker sHER2 directly from serum and saliva samples by a nanorod-based homogeneous biosensing approach, which is easy to operate as it only requires mixing of the samples with the nanorod probes. By careful nanorod surface engineering and homogeneous assay design, we demonstrate that the formation of a protein corona around the nanoparticles does not limit the applicability of our detection method, but on the contrary enables us to conduct in-situ reference measurements, thus further strengthening the point-of-care applicability of our method. Making use of sandwich assays on top of the nanorods, we obtain a limit of detection of 110 pM and 470 pM in 10-fold diluted spiked saliva and serum samples, respectively. In conclusion, our results open up numerous applications in direct protein biomarker quantification, specifically in point-of-care settings where resources are limited and ease-of-use is of essence.

  12. From LIDAR Scanning to 3d FEM Analysis for Complex Surface and Underground Excavations

    Science.gov (United States)

    Chun, K.; Kemeny, J.

    2017-12-01

    Light detection and ranging (LIDAR) has been a prevalent remote-sensing technology applied in the geological fields due to its high precision and ease to use. One of the major applications is to use the detailed geometrical information of underground structures as a basis for the generation of three-dimensional numerical model that can be used in FEM analysis. To date, however, straightforward techniques in reconstructing numerical model from the scanned data of underground structures have not been well established or tested. In this paper, we propose a comprehensive approach integrating from LIDAR scanning to finite element numerical analysis, specifically converting LIDAR 3D point clouds of object containing complex surface geometry into finite element model. This methodology has been applied to the Kartchner Caverns in Arizona for the stability analysis. Numerical simulations were performed using the finite element code ABAQUS. The results indicate that the highlights of our technologies obtained from LIDAR is effective and provide reference for other similar engineering project in practice.

  13. Explicit validation of a surface shortwave radiation balance model over snow-covered complex terrain

    Science.gov (United States)

    Helbig, N.; Löwe, H.; Mayer, B.; Lehning, M.

    2010-09-01

    A model that computes the surface radiation balance for all sky conditions in complex terrain is presented. The spatial distribution of direct and diffuse sky radiation is determined from observations of incident global radiation, air temperature, and relative humidity at a single measurement location. Incident radiation under cloudless sky is spatially derived from a parameterization of the atmospheric transmittance. Direct and diffuse sky radiation for all sky conditions are obtained by decomposing the measured global radiation value. Spatial incident radiation values under all atmospheric conditions are computed by adjusting the spatial radiation values obtained from the parametric model with the radiation components obtained from the decomposition model at the measurement site. Topographic influences such as shading are accounted for. The radiosity approach is used to compute anisotropic terrain reflected radiation. Validations of the shortwave radiation balance model are presented in detail for a day with cloudless sky. For a day with overcast sky a first validation is presented. Validation of a section of the horizon line as well as of individual radiation components is performed with high-quality measurements. A new measurement setup was designed to determine terrain reflected radiation. There is good agreement between the measurements and the modeled terrain reflected radiation values as well as with incident radiation values. A comparison of the model with a fully three-dimensional radiative transfer Monte Carlo model is presented. That validation reveals a good agreement between modeled radiation values.

  14. Direct protein quantification in complex sample solutions by surface-engineered nanorod probes

    KAUST Repository

    Schrittwieser, Stefan; Pelaz, Beatriz; Parak, Wolfgang J.; Lentijo Mozo, Sergio; Soulantica, Katerina; Dieckhoff, Jan; Ludwig, Frank; Schotter, Joerg

    2017-01-01

    Detecting biomarkers from complex sample solutions is the key objective of molecular diagnostics. Being able to do so in a simple approach that does not require laborious sample preparation, sophisticated equipment and trained staff is vital for point-of-care applications. Here, we report on the specific detection of the breast cancer biomarker sHER2 directly from serum and saliva samples by a nanorod-based homogeneous biosensing approach, which is easy to operate as it only requires mixing of the samples with the nanorod probes. By careful nanorod surface engineering and homogeneous assay design, we demonstrate that the formation of a protein corona around the nanoparticles does not limit the applicability of our detection method, but on the contrary enables us to conduct in-situ reference measurements, thus further strengthening the point-of-care applicability of our method. Making use of sandwich assays on top of the nanorods, we obtain a limit of detection of 110 pM and 470 pM in 10-fold diluted spiked saliva and serum samples, respectively. In conclusion, our results open up numerous applications in direct protein biomarker quantification, specifically in point-of-care settings where resources are limited and ease-of-use is of essence.

  15. Adsorption of uranium(VI) to manganese oxides: X-ray absorption spectroscopy and surface complexation modeling.

    Science.gov (United States)

    Wang, Zimeng; Lee, Sung-Woo; Catalano, Jeffrey G; Lezama-Pacheco, Juan S; Bargar, John R; Tebo, Bradley M; Giammar, Daniel E

    2013-01-15

    The mobility of hexavalent uranium in soil and groundwater is strongly governed by adsorption to mineral surfaces. As strong naturally occurring adsorbents, manganese oxides may significantly influence the fate and transport of uranium. Models for U(VI) adsorption over a broad range of chemical conditions can improve predictive capabilities for uranium transport in the subsurface. This study integrated batch experiments of U(VI) adsorption to synthetic and biogenic MnO(2), surface complexation modeling, ζ-potential analysis, and molecular-scale characterization of adsorbed U(VI) with extended X-ray absorption fine structure (EXAFS) spectroscopy. The surface complexation model included inner-sphere monodentate and bidentate surface complexes and a ternary uranyl-carbonato surface complex, which was consistent with the EXAFS analysis. The model could successfully simulate adsorption results over a broad range of pH and dissolved inorganic carbon concentrations. U(VI) adsorption to synthetic δ-MnO(2) appears to be stronger than to biogenic MnO(2), and the differences in adsorption affinity and capacity are not associated with any substantial difference in U(VI) coordination.

  16. Correlation of gamma spectrometer measurements at surface with concentrations and distributions of subsurface radium contamination: Development, verification and application of methodology

    International Nuclear Information System (INIS)

    McCallum, B.A.; Clement, C.H.; Huffman, D.; Stager, R.H.

    2000-01-01

    This work is a step forward in the investigation of data gathering principles and analysis tools for improved estimates of subsurface radium contamination concentrations and distributions using surface gamma radiation spectra. Techniques to solve the inverse problem of estimating surface gamma radiation spectra given a fully known subsurface radium distribution have been investigated and applied with success. These techniques fell into three broad categories: empirical (using laboratory and field data), analytical (using mathematical derivations of relationships), and computer simulation (using Monte-Carlo photon transport simulation methods). Methods of analyzing surface spectra to estimate certain source parameters have been studied. The most fully developed methods are those involving the ratio of the areas of two peaks of differing energy from the same radionuclide to determine the source depth. For a point source of radium and its progeny, these techniques are able to reliably estimate the source depth from a single gamma radiation spectrum taken at the surface directly above the source. The only significant uncertainties in this case are the soil density and uncertainties introduced as a result of counting statistics. Further work remains to fully achieve the goals of the larger project: to develop a comprehensive suite of tools for the improved interpretation of surface gamma radiation spectra from subsurface distributions of radium contaminated soil. (author)

  17. DFT study of benzyl alcohol/TiO2 interfacial surface complex: reaction pathway and mechanism of visible light absorption.

    Science.gov (United States)

    Zhao, Lei; Gu, Feng Long; Kim, Minjae; Miao, Maosheng; Zhang, Rui-Qin

    2017-09-24

    We propose a new pathway for the adsorption of benzyl alcohol on the surface of TiO 2 and the formation of interfacial surface complex (ISC). The reaction free energies and reaction kinetics were thoroughly investigated by density functional calculations. The TiO 2 surfaces were modeled by clusters consisting of 4 Ti atoms and 18 O atoms passivated by H, OH group and H 2 O molecules. Compared with solid-state calculations utilizing the periodicity of the materials, such cluster modeling allows inclusion of the high-order correlation effects that seem to be essential for the adsorption of organic molecules onto solid surfaces. The effects of both acidity and solvation are included in our calculations, which demonstrate that the new pathway is competitive with a previous pathway. The electronic structure calculations based on the relaxed ISC structures reveal that the chemisorption of benzyl alcohol on the TiO 2 surface greatly alters the nature of the frontier molecular orbitals. The resulted reduced energy gap in ISC matches the energy of visible light, showing how the adsorption of benzyl alcohol sensitizes the TiO 2 surface. Graphical Abstract The chemisorption of benzyl alcohol on TiO 2 surface greatly alters the nature of the frontier molecular orbitals and the formed interfacial surface complex can be sensitized by visible light.

  18. Re-Inversion of Surface Electrical Resistivity Tomography Data from the Hanford Site B-Complex

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Timothy C.; Wellman, Dawn M.

    2013-05-01

    This report documents the three-dimensional (3D) inversion results of surface electrical resistivity tomography (ERT) data collected over the Hanford Site B-Complex. The data were collected in order to image the subsurface distribution of electrically conductive vadose zone contamination resulting from both planned releases of contamination into subsurface infiltration galleries (cribs, trenches, and tile fields), as well as unplanned releases from the B, BX, and BY tank farms and/or associated facilities. Electrically conductive contaminants are those which increase the ionic strength of pore fluids compared to native conditions, which comprise most types of solutes released into the subsurface B-Complex. The ERT data were collected and originally inverted as described in detail in report RPP-34690 Rev 0., 2007, which readers should refer to for a detailed description of data collection and waste disposal history. Although the ERT imaging results presented in that report successfully delineated the footprint of vadose zone contamination in areas outside of the tank farms, imaging resolution was not optimized due to the inability of available inversion codes to optimally process the massive ERT data set collected at the site. Recognizing these limitations and the potential for enhanced ERT characterization and time-lapse imaging at contaminated sites, a joint effort was initiated in 2007 by the U.S. Department of Energy – Office of Science (DOE-SC), with later support by the Office of Environmental Management (DOE-EM), and the U.S. Department of Defense (DOD), to develop a high-performance distributed memory parallel 3D ERT inversion code capable of optimally processing large ERT data sets. The culmination of this effort was the development of E4D (Johnson et al., 2010,2012) In 2012, under the Deep Vadose Zone Applied Field Research Initiative (DVZ-AFRI), the U.S. Department of Energy – Richland Operations Office (DOE-RL) and CH2M Hill Plateau Remediation

  19. Structure and reactivity of heterogeneous surfaces and study of the geometry of surface complexes. Progress report, January 1, 1984-December 31, 1984

    International Nuclear Information System (INIS)

    Landman, U.

    1984-01-01

    Since the beginning of this project, our group has been involved in theoretical studies of surface phenomena and processes, aimed toward increasing our understanding of fundamental processes which govern the properties of material surfaces. Our studies cover a wide spectrum of surface phenomena: surface reactivity, surface crystallography, electronic and vibrational structure, dynamical processes, phase transformations and phase change, the properties of interfaces and investigations of material processing and novel materials preparation techniques. In these investigations we develop and employ analytical and novel numerical, simulation, methods for the study of complex surface phenomena. Our recent surface molecular dynamics studies and simulations of laser annealing phenomena opened new avenues for the investigation of the microscopic dynamics and evolution of equilibrium and non-equilibrium processes at surfaces and interfaces. Our current studies of metallic glasses using a new langrangian formulation which includes all components of the total energy (density dependent electron gas, single particle and pair interactions) of the system, represents a novel approach for theoretical studies of this important class of systems

  20. Engineering the cell surface display of cohesins for assembly of cellulosome-inspired enzyme complexes on Lactococcus lactis

    Directory of Open Access Journals (Sweden)

    Wieczorek Andrew S

    2010-09-01

    Full Text Available Abstract Background The assembly and spatial organization of enzymes in naturally occurring multi-protein complexes is of paramount importance for the efficient degradation of complex polymers and biosynthesis of valuable products. The degradation of cellulose into fermentable sugars by Clostridium thermocellum is achieved by means of a multi-protein "cellulosome" complex. Assembled via dockerin-cohesin interactions, the cellulosome is associated with the cell surface during cellulose hydrolysis, forming ternary cellulose-enzyme-microbe complexes for enhanced activity and synergy. The assembly of recombinant cell surface displayed cellulosome-inspired complexes in surrogate microbes is highly desirable. The model organism Lactococcus lactis is of particular interest as it has been metabolically engineered to produce a variety of commodity chemicals including lactic acid and bioactive compounds, and can efficiently secrete an array of recombinant proteins and enzymes of varying sizes. Results Fragments of the scaffoldin protein CipA were functionally displayed on the cell surface of Lactococcus lactis. Scaffolds were engineered to contain a single cohesin module, two cohesin modules, one cohesin and a cellulose-binding module, or only a cellulose-binding module. Cell toxicity from over-expression of the proteins was circumvented by use of the nisA inducible promoter, and incorporation of the C-terminal anchor motif of the streptococcal M6 protein resulted in the successful surface-display of the scaffolds. The facilitated detection of successfully secreted scaffolds was achieved by fusion with the export-specific reporter staphylococcal nuclease (NucA. Scaffolds retained their ability to associate in vivo with an engineered hybrid reporter enzyme, E. coli β-glucuronidase fused to the type 1 dockerin motif of the cellulosomal enzyme CelS. Surface-anchored complexes exhibited dual enzyme activities (nuclease and β-glucuronidase, and were

  1. Application of a surface complexation model to the interactions of Pu and Am with Esk Estuary sediments

    International Nuclear Information System (INIS)

    Turner, D.R.; Knox, S.; Titley, J.G.; Hamilton-Taylor, J.; Kelly, M.; Williams, G.

    1990-10-01

    Previous work has shown that Pu is remobilised from Esk sediments at low salinities of overlying water. A constant capacitance surface complexation model has been developed in order to understand and model the chemical processes occurring. The model is based on detailed chemical characterisation of sediment samples from the estuary. The following measurements were carried out to provide input parameters for the model: specific surface area; total surface sites (tritium exchange); proton and major ion exchange (potentiometric titration); and actinide (Pu and Am) partition coefficient as a function of pH and salinity at sediment and actinide concentrations typical of the Esk. (author)

  2. Verification of Ceramic Structures

    Science.gov (United States)

    Behar-Lafenetre, Stephanie; Cornillon, Laurence; Rancurel, Michael; De Graaf, Dennis; Hartmann, Peter; Coe, Graham; Laine, Benoit

    2012-07-01

    In the framework of the “Mechanical Design and Verification Methodologies for Ceramic Structures” contract [1] awarded by ESA, Thales Alenia Space has investigated literature and practices in affiliated industries to propose a methodological guideline for verification of ceramic spacecraft and instrument structures. It has been written in order to be applicable to most types of ceramic or glass-ceramic materials - typically Cesic®, HBCesic®, Silicon Nitride, Silicon Carbide and ZERODUR®. The proposed guideline describes the activities to be performed at material level in order to cover all the specific aspects of ceramics (Weibull distribution, brittle behaviour, sub-critical crack growth). Elementary tests and their post-processing methods are described, and recommendations for optimization of the test plan are given in order to have a consistent database. The application of this method is shown on an example in a dedicated article [7]. Then the verification activities to be performed at system level are described. This includes classical verification activities based on relevant standard (ECSS Verification [4]), plus specific analytical, testing and inspection features. The analysis methodology takes into account the specific behaviour of ceramic materials, especially the statistical distribution of failures (Weibull) and the method to transfer it from elementary data to a full-scale structure. The demonstration of the efficiency of this method is described in a dedicated article [8]. The verification is completed by classical full-scale testing activities. Indications about proof testing, case of use and implementation are given and specific inspection and protection measures are described. These additional activities are necessary to ensure the required reliability. The aim of the guideline is to describe how to reach the same reliability level as for structures made of more classical materials (metals, composites).

  3. Verification and validation benchmarks.

    Energy Technology Data Exchange (ETDEWEB)

    Oberkampf, William Louis; Trucano, Timothy Guy

    2007-02-01

    Verification and validation (V&V) are the primary means to assess the accuracy and reliability of computational simulations. V&V methods and procedures have fundamentally improved the credibility of simulations in several high-consequence fields, such as nuclear reactor safety, underground nuclear waste storage, and nuclear weapon safety. Although the terminology is not uniform across engineering disciplines, code verification deals with assessing the reliability of the software coding, and solution verification deals with assessing the numerical accuracy of the solution to a computational model. Validation addresses the physics modeling accuracy of a computational simulation by comparing the computational results with experimental data. Code verification benchmarks and validation benchmarks have been constructed for a number of years in every field of computational simulation. However, no comprehensive guidelines have been proposed for the construction and use of V&V benchmarks. For example, the field of nuclear reactor safety has not focused on code verification benchmarks, but it has placed great emphasis on developing validation benchmarks. Many of these validation benchmarks are closely related to the operations of actual reactors at near-safety-critical conditions, as opposed to being more fundamental-physics benchmarks. This paper presents recommendations for the effective design and use of code verification benchmarks based on manufactured solutions, classical analytical solutions, and highly accurate numerical solutions. In addition, this paper presents recommendations for the design and use of validation benchmarks, highlighting the careful design of building-block experiments, the estimation of experimental measurement uncertainty for both inputs and outputs to the code, validation metrics, and the role of model calibration in validation. It is argued that the understanding of predictive capability of a computational model is built on the level of

  4. Verification and validation benchmarks

    International Nuclear Information System (INIS)

    Oberkampf, William Louis; Trucano, Timothy Guy

    2007-01-01

    Verification and validation (V and V) are the primary means to assess the accuracy and reliability of computational simulations. V and V methods and procedures have fundamentally improved the credibility of simulations in several high-consequence fields, such as nuclear reactor safety, underground nuclear waste storage, and nuclear weapon safety. Although the terminology is not uniform across engineering disciplines, code verification deals with assessing the reliability of the software coding, and solution verification deals with assessing the numerical accuracy of the solution to a computational model. Validation addresses the physics modeling accuracy of a computational simulation by comparing the computational results with experimental data. Code verification benchmarks and validation benchmarks have been constructed for a number of years in every field of computational simulation. However, no comprehensive guidelines have been proposed for the construction and use of V and V benchmarks. For example, the field of nuclear reactor safety has not focused on code verification benchmarks, but it has placed great emphasis on developing validation benchmarks. Many of these validation benchmarks are closely related to the operations of actual reactors at near-safety-critical conditions, as opposed to being more fundamental-physics benchmarks. This paper presents recommendations for the effective design and use of code verification benchmarks based on manufactured solutions, classical analytical solutions, and highly accurate numerical solutions. In addition, this paper presents recommendations for the design and use of validation benchmarks, highlighting the careful design of building-block experiments, the estimation of experimental measurement uncertainty for both inputs and outputs to the code, validation metrics, and the role of model calibration in validation. It is argued that the understanding of predictive capability of a computational model is built on the

  5. Verification and validation benchmarks

    International Nuclear Information System (INIS)

    Oberkampf, William L.; Trucano, Timothy G.

    2008-01-01

    Verification and validation (V and V) are the primary means to assess the accuracy and reliability of computational simulations. V and V methods and procedures have fundamentally improved the credibility of simulations in several high-consequence fields, such as nuclear reactor safety, underground nuclear waste storage, and nuclear weapon safety. Although the terminology is not uniform across engineering disciplines, code verification deals with assessing the reliability of the software coding, and solution verification deals with assessing the numerical accuracy of the solution to a computational model. Validation addresses the physics modeling accuracy of a computational simulation by comparing the computational results with experimental data. Code verification benchmarks and validation benchmarks have been constructed for a number of years in every field of computational simulation. However, no comprehensive guidelines have been proposed for the construction and use of V and V benchmarks. For example, the field of nuclear reactor safety has not focused on code verification benchmarks, but it has placed great emphasis on developing validation benchmarks. Many of these validation benchmarks are closely related to the operations of actual reactors at near-safety-critical conditions, as opposed to being more fundamental-physics benchmarks. This paper presents recommendations for the effective design and use of code verification benchmarks based on manufactured solutions, classical analytical solutions, and highly accurate numerical solutions. In addition, this paper presents recommendations for the design and use of validation benchmarks, highlighting the careful design of building-block experiments, the estimation of experimental measurement uncertainty for both inputs and outputs to the code, validation metrics, and the role of model calibration in validation. It is argued that the understanding of predictive capability of a computational model is built on the

  6. Titanium biomaterials with complex surfaces induced aberrant peripheral circadian rhythms in bone marrow mesenchymal stromal cells.

    Science.gov (United States)

    Hassan, Nathaniel; McCarville, Kirstin; Morinaga, Kenzo; Mengatto, Cristiane M; Langfelder, Peter; Hokugo, Akishige; Tahara, Yu; Colwell, Christopher S; Nishimura, Ichiro

    2017-01-01

    Circadian rhythms maintain a high level of homeostasis through internal feed-forward and -backward regulation by core molecules. In this study, we report the highly unusual peripheral circadian rhythm of bone marrow mesenchymal stromal cells (BMSCs) induced by titanium-based biomaterials with complex surface modifications (Ti biomaterial) commonly used for dental and orthopedic implants. When cultured on Ti biomaterials, human BMSCs suppressed circadian PER1 expression patterns, while NPAS2 was uniquely upregulated. The Ti biomaterials, which reduced Per1 expression and upregulated Npas2, were further examined with BMSCs harvested from Per1::luc transgenic rats. Next, we addressed the regulatory relationship between Per1 and Npas2 using BMSCs from Npas2 knockout mice. The Npas2 knockout mutation did not rescue the Ti biomaterial-induced Per1 suppression and did not affect Per2, Per3, Bmal1 and Clock expression, suggesting that the Ti biomaterial-induced Npas2 overexpression was likely an independent phenomenon. Previously, vitamin D deficiency was reported to interfere with Ti biomaterial osseointegration. The present study demonstrated that vitamin D supplementation significantly increased Per1::luc expression in BMSCs, though the presence of Ti biomaterials only moderately affected the suppressed Per1::luc expression. Available in vivo microarray data from femurs exposed to Ti biomaterials in vitamin D-deficient rats were evaluated by weighted gene co-expression network analysis. A large co-expression network containing Npas2, Bmal1, and Vdr was observed to form with the Ti biomaterials, which was disintegrated by vitamin D deficiency. Thus, the aberrant BMSC peripheral circadian rhythm may be essential for the integration of Ti biomaterials into bone.

  7. Model complexity in carbon sequestration:A design of experiment and response surface uncertainty analysis

    Science.gov (United States)

    Zhang, Y.; Li, S.

    2014-12-01

    Geologic carbon sequestration (GCS) is proposed for the Nugget Sandstone in Moxa Arch, a regional saline aquifer with a large storage potential. For a proposed storage site, this study builds a suite of increasingly complex conceptual "geologic" model families, using subsets of the site characterization data: a homogeneous model family, a stationary petrophysical model family, a stationary facies model family with sub-facies petrophysical variability, and a non-stationary facies model family (with sub-facies variability) conditioned to soft data. These families, representing alternative conceptual site models built with increasing data, were simulated with the same CO2 injection test (50 years at 1/10 Mt per year), followed by 2950 years of monitoring. Using the Design of Experiment, an efficient sensitivity analysis (SA) is conducted for all families, systematically varying uncertain input parameters. Results are compared among the families to identify parameters that have 1st order impact on predicting the CO2 storage ratio (SR) at both end of injection and end of monitoring. At this site, geologic modeling factors do not significantly influence the short-term prediction of the storage ratio, although they become important over monitoring time, but only for those families where such factors are accounted for. Based on the SA, a response surface analysis is conducted to generate prediction envelopes of the storage ratio, which are compared among the families at both times. Results suggest a large uncertainty in the predicted storage ratio given the uncertainties in model parameters and modeling choices: SR varies from 5-60% (end of injection) to 18-100% (end of monitoring), although its variation among the model families is relatively minor. Moreover, long-term leakage risk is considered small at the proposed site. In the lowest-SR scenarios, all families predict gravity-stable supercritical CO2 migrating toward the bottom of the aquifer. In the highest

  8. Reload core safety verification

    International Nuclear Information System (INIS)

    Svetlik, M.; Minarcin, M.

    2003-01-01

    This paper presents a brief look at the process of reload core safety evaluation and verification in Slovak Republic. It gives an overview of experimental verification of selected nuclear parameters in the course of physics testing during reactor start-up. The comparison of IAEA recommendations and testing procedures at Slovak and European nuclear power plants of similar design is included. An introduction of two level criteria for evaluation of tests represents an effort to formulate the relation between safety evaluation and measured values (Authors)

  9. The complexity of identifying Ryu-Takayanagi surfaces in AdS{sub 3}/CFT{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Bao, N.; Chatwin-Davies, A. [Walter Burke Institute for Theoretical Physics, California Institute of Technology,Pasadena, CA 91125 (United States)

    2016-11-07

    We present a constructive algorithm for the determination of Ryu-Takayanagi surfaces in AdS{sub 3}/CFT{sub 2} which exploits previously noted connections between holographic entanglement entropy and max-flow/min-cut. We then characterize its complexity as a polynomial time algorithm.

  10. Field Verification Program (Upland Disposal): Prediction of Surface Runoff Water Quality from Black Rock Harbor Dredged Material Placed in an Upland Disposal Site.

    Science.gov (United States)

    1987-03-01

    Simulator was similar to the original rotating disk-type rainfall simulator but had several important design modifications ( Westerdahl and Skogerboe...exist- ing vegetation on the soil surface ( Westerdahl and Skogerboe 1982). A multiple-peaked natural storm event was selected from field data and pro... Westerdahl and Skogerboe 1982) and has been used as a standard storm event for comparison to natural storm events (Laws and Parsons 1943). Similar

  11. Molecular and electronic structure of osmium complexes confined to Au(111) surfaces using a self-assembled molecular bridge

    Energy Technology Data Exchange (ETDEWEB)

    Llave, Ezequiel de la; Herrera, Santiago E.; Adam, Catherine; Méndez De Leo, Lucila P.; Calvo, Ernesto J.; Williams, Federico J., E-mail: fwilliams@qi.fcen.uba.ar [INQUIMAE-CONICET, Departamento de Química Inorgánica, Analítica y Química-Física, Facultad Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón 2, Buenos Aires C1428EHA (Argentina)

    2015-11-14

    The molecular and electronic structure of Os(II) complexes covalently bonded to self-assembled monolayers (SAMs) on Au(111) surfaces was studied by means of polarization modulation infrared reflection absorption spectroscopy, photoelectron spectroscopies, scanning tunneling microscopy, scanning tunneling spectroscopy, and density functional theory calculations. Attachment of the Os complex to the SAM proceeds via an amide covalent bond with the SAM alkyl chain 40° tilted with respect to the surface normal and a total thickness of 26 Å. The highest occupied molecular orbital of the Os complex is mainly based on the Os(II) center located 2.2 eV below the Fermi edge and the LUMO molecular orbital is mainly based on the bipyridine ligands located 1.5 eV above the Fermi edge.

  12. The RSV F and G glycoproteins interact to form a complex on the surface of infected cells

    International Nuclear Information System (INIS)

    Low, Kit-Wei; Tan, Timothy; Ng, Ken; Tan, Boon-Huan; Sugrue, Richard J.

    2008-01-01

    In this study, the interaction between the respiratory syncytial virus (RSV) fusion (F) protein, attachment (G) protein, and small hydrophobic (SH) proteins was examined. Immunoprecipitation analysis suggested that the F and G proteins exist as a protein complex on the surface of RSV-infected cells, and this conclusion was supported by ultracentrifugation analysis that demonstrated co-migration of surface-expressed F and G proteins. Although our analysis provided evidence for an interaction between the G and SH proteins, no evidence was obtained for a single protein complex involving all three of the virus proteins. These data suggest the existence of multiple virus glycoprotein complexes within the RSV envelope. Although the stimulus that drives RSV-mediated membrane fusion is unknown, the association between the G and F proteins suggest an indirect role for the G protein in this process

  13. Remaining Sites Verification Package for the 100-B-1 Surface Chemical and Solid Waste Dumping Area,. Attachment to Waste Site Reclassification Form 2006-003

    International Nuclear Information System (INIS)

    Carlson, R.A.

    2006-01-01

    The 100-B-1 waste site was a dumping site that was divided into two areas. One area was used as a laydown area for construction materials, and the other area was used as a chemical dumping area. The 100-B-1 Surface Chemical and Solid Waste Dumping Area site meets the remedial action objectives specified in the Remaining Sites ROD. The results demonstrate that residual contaminant concentrations support future unrestricted land uses that can be represented by a rural-residential scenario. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River

  14. Is flow verification necessary

    International Nuclear Information System (INIS)

    Beetle, T.M.

    1986-01-01

    Safeguards test statistics are used in an attempt to detect diversion of special nuclear material. Under assumptions concerning possible manipulation (falsification) of safeguards accounting data, the effects on the statistics due to diversion and data manipulation are described algebraically. A comprehensive set of statistics that is capable of detecting any diversion of material is defined in terms of the algebraic properties of the effects. When the assumptions exclude collusion between persons in two material balance areas, then three sets of accounting statistics are shown to be comprehensive. Two of the sets contain widely known accountancy statistics. One of them does not require physical flow verification - comparisons of operator and inspector data for receipts and shipments. The third set contains a single statistic which does not require physical flow verification. In addition to not requiring technically difficult and expensive flow verification, this single statistic has several advantages over other comprehensive sets of statistics. This algebraic approach as an alternative to flow verification for safeguards accountancy is discussed in this paper

  15. Integrated Java Bytecode Verification

    DEFF Research Database (Denmark)

    Gal, Andreas; Probst, Christian; Franz, Michael

    2005-01-01

    Existing Java verifiers perform an iterative data-flow analysis to discover the unambiguous type of values stored on the stack or in registers. Our novel verification algorithm uses abstract interpretation to obtain definition/use information for each register and stack location in the program...

  16. Axisymmetric flow in a cylindrical tank over a rotating bottom. Part II. Deformation of the water surface and experimental verification of the theory

    Energy Technology Data Exchange (ETDEWEB)

    Iga, Keita; Watanabe, Shunichi; Niino, Hiroshi; Misawa, Nobuhiko [Atmosphere and Ocean Research Institute, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa, Chiba 277-8564 (Japan); Yokota, Sho [Meteorological Research Institute, 1-1 Nagamine, Tsukuba, Ibaraki 305-0052 (Japan); Ikeda, Takashi, E-mail: iga@aori.u-tokyo.ac.jp [Japan Patent Office, 3-4-3 Kasumigaseki, Chiyoda, Tokyo 100-8915 (Japan)

    2017-12-15

    The theory of axisymmetric flow in a cylindrical container with a rotating bottom, as described in Part I, is validated against the results of previous and our own laboratory experiments. First, deformation of the water surface is derived using the velocity distribution of the axisymmetric flow obtained by the theory. The form of the water surface is classified into three regimes, and the rotation rates of the transitions between these regimes are determined. The parameters predicted from this theory are compared with the results measured in laboratory experiments and also with data from previous experimental studies. The theory predicts the experimental data well, but a slight difference was found in the narrow region close to the side wall. Corrections estimated by considering the fluid behavior around the side wall boundary layer successfully explain most of the discrepancies. This theory appears to predict the results of the laboratory experiments very well, much better than a theory using an assumption of quadratic drag as a model of turbulent boundary layers. (paper)

  17. Planification de trajectoires pour placement automatise de fibres sur surfaces de geometries complexes

    Science.gov (United States)

    Hely, Clement

    During the past 50 years, the use of composite materials drastically increase, mainly thanks to the interest of aeronautical industries for these strong and lightweight materials. To improve the productivity of composite materials manufacturing some of the largest aeronautics companies began to develop automated processes such as Automated Fibre Placement (AFP). The AFP workcells currently used by the industry were mainly developed for production of large, nearly flat, plates with low curvatures such as aircraft fuselages. However, the fields of aeronautics and sport goods production begin nowadays to show an interest for manufacturing of smaller and more complex parts. The aim of the project in which this research takes place is to design a new AFP workcell and to develop new techniques allowing production of parts with small size and complex geometry. The work presented in this thesis focuses on the path planning on multi-axial revolution surfaces, e.g. Y-shaped tubes of constant circular cross section. Several path planning algorithms will be presented aiming at the exhaustive coverage of a mandrel with pre-impregnated (prepreg) composite tape. The methodology used in two of these algorithms is to individually cover each branch of the Y-shaped part with paths deriving from a helix. In the first one, the helix will be cut at the boundary between a branch and the junction region (algorithm HD) while in the second (algorithm HA) the pseudo-helix path can be adjusted to follow this boundary. These two methods were shown to have some drawbacks compromising their practical use and possibly leading to parts with diminished mechanical properties. To avoid these drawbacks, two others algorithms were developed with a new methodology. With them, the aim is to cover two branches of the Y-shape with a continuous course (i.e. without cut). The first one uses a well known strategy which defines plies with a constant fibre orientation. Parallel paths are then computed to

  18. Energy transfer between surface-immobilized light-harvesting chlorophyll a/b complex (LHCII) studied by surface plasmon field-enhanced fluorescence spectroscopy (SPFS).

    Science.gov (United States)

    Lauterbach, Rolf; Liu, Jing; Knoll, Wolfgang; Paulsen, Harald

    2010-11-16

    The major light-harvesting chlorophyll a/b complex (LHCII) of the photosynthetic apparatus in green plants can be viewed as a protein scaffold binding and positioning a large number of pigment molecules that combines rapid and efficient excitation energy transfer with effective protection of its pigments from photobleaching. These properties make LHCII potentially interesting as a light harvester (or a model thereof) in photoelectronic applications. Most of such applications would require the LHCII to be immobilized on a solid surface. In a previous study we showed the immobilization of recombinant LHCII on functionalized gold surfaces via a 6-histidine tag (His tag) in the protein moiety. In this work the occurrence and efficiency of Förster energy transfer between immobilized LHCII on a functionalized surface have been analyzed by surface plasmon field-enhanced fluorescence spectroscopy (SPFS). A near-infrared dye was attached to some but not all of the LHC complexes, serving as an energy acceptor to chlorophylls. Analysis of the energy transfer from chlorophylls to this acceptor dye yielded information about the extent of intercomplex energy transfer between immobilized LHCII.

  19. Retrievals of Surface Air Temperature Using Multiple Satellite Data Combinations over Complex Terrain in the Korean Peninsula

    Science.gov (United States)

    Jang, K.; Won, M.; Yoon, S.; Lim, J.

    2016-12-01

    Surface air temperature (Tair) is a fundamental factor for terrestrial environments and plays a major role in the fields of applied meteorology, climatology, and ecology. The satellite remotely sensed data offers the opportunity to estimate Tair on the earth's surface with high spatial and temporal resolutions. The Moderate Resolution Imaging Spectroradiometer (MODIS) provides effective Tair retrievals although restricted to clear sky condition. MODIS Tair over complex terrain can result in significant retrieval errors due to the retrieval height mismatch to the elevation of local weather stations. In this study, we propose the methodology to estimate Tair over complex terrain for all sky conditions using multiple satellite data fusion based on the pixel-wise regression method. The combination of synergistic information from MODIS Tair and the brightness temperature (Tb) retrievals at 37 GHz frequency from the satellite microwave sensor were used for analysis. The air temperature lapse rate was applied to estimate the near-surface Tair considering the complex terrain such as mountainous regions. The retrieval results produced from this study showed a good agreement (RMSE Administration (KMA). The gaps in the MODIS Tair data due to cloud contamination were successfully filled using the proposed method which yielded similar accuracy as retrievals of clear sky. The results of this study indicate that the satellite data fusion can continuously produce Tair retrievals with reasonable accuracy and that the application of the temperature lapse rate can lead to improvement of the reliability over complex terrains such as the Korean Peninsula.

  20. Verification Games: Crowd-Sourced Formal Verification

    Science.gov (United States)

    2016-03-01

    additional paintbrushes. Additionally, in Paradox , human players are never given small optimization problems (for example, toggling the values of 50...were developed by the Center for Game Science: Pipe Jam, Traffic Jam, Flow Jam and Paradox . Verification tools and games were integrated to verify...4 4. Paradox …………………………………………………......5 5. MyClass ………………………………………………….....7 6. Results …………………………………………………......11 7. Time to

  1. Guest-Host Complex Formed between Ascorbic Acid and β-Cyclodextrin Immobilized on the Surface of an Electrode

    Directory of Open Access Journals (Sweden)

    María Teresa Ramírez-Silva

    2014-05-01

    Full Text Available This work deals with the formation of supramolecular complexes between ascorbic acid (AA, the guest, and β-cyclodextrin (β-CD, the host, that was first potentiodynamically immobilized on the surface of a carbon paste electrode (CPE throughout the formation of a β-CD-based conducting polymer (poly-β-CD. With the bare CPE and the β-CD-modified CPE, an electrochemical study was performed to understand the effect of such surface modification on the electrochemical response of the AA. From this study it was shown that on the modified-CPE, the AA was surface-immobilized through formation of an inclusion complex with β-CD, which provoked the adsorption of AA in such a way that this stage became the limiting step for the electrochemical oxidation of AA. Moreover, from the analysis of the experimental voltammetric plots recorded during AA oxidation on the CPE/poly-β-CD electrode surfaces, the Gibbs’ standard free energy of the inclusion complex formed by the oxidation product of AA and β-CD has been determined for the first time, ∆G0inclus = −36.4 kJ/mol.

  2. The need for verification of the Polish lignite deposits owing to development and nature conservation protection on land at the surface

    Directory of Open Access Journals (Sweden)

    Naworyta Wojciech

    2016-12-01

    Full Text Available Poland is a country rich in lignite. The area where the lignite occurs occupies approx. 22% of the total surface area of the country. Geological resources of Polish lignite deposits are estimated at 23.5 billion Mg, but in the majority (69% the accuracy of their identification is poor. Nevertheless the amount of coal in Polish deposits allows - at least in theory - for mining and energy production at the current level for hundreds of years to come. It is an important raw material for the energy security of the country both currently and in the future. Because the vast majority of Polish and foreign mines use an open pit method for lignite extraction the actual amount of mineral available for the extraction depends not only on the properties of the deposit but to a large extent on the method of development of the surface land above the deposit, as well as on the sensitivity of the environment in the vicinity of any future mines. After careful analysis it can be stated that only a few of the lignite deposits may be subject to cost-effective mining operations. These deposits should be subjected to special protection as a future resource base which will ensure the energy security of the country. Some examples of domestic deposits have been presented where due to the conflict resulting from the development of the area should be deleted from the Balance Sheet of Mineral Deposits because their exploitation is irrational and uneconomic. Keeping such deposits in the Balance Sheet, and the use of large numbers in the context of their resource base leads to an unwarranted sense of wealth which consequently does not encourage the protection of these deposits which may actually be subject to rational exploitation in the near future. In summary there is a need to find a compromise in order to adequately protect all natural resources including mineral deposits.

  3. Automated Formal Verification for PLC Control Systems

    CERN Multimedia

    Fernández Adiego, Borja

    2014-01-01

    Programmable Logic Controllers (PLCs) are widely used devices used in industrial control systems. Ensuring that the PLC software is compliant with its specification is a challenging task. Formal verification has become a recommended practice to ensure the correctness of the safety-critical software. However, these techniques are still not widely applied in industry due to the complexity of building formal models, which represent the system and the formalization of requirement specifications. We propose a general methodology to perform automated model checking of complex properties expressed in temporal logics (e.g. CTL, LTL) on PLC programs. This methodology is based on an Intermediate Model (IM), meant to transform PLC programs written in any of the languages described in the IEC 61131-3 standard (ST, IL, etc.) to different modeling languages of verification tools. This approach has been applied to CERN PLC programs validating the methodology.

  4. Android-Based Verification System for Banknotes

    Directory of Open Access Journals (Sweden)

    Ubaid Ur Rahman

    2017-11-01

    Full Text Available With the advancement in imaging technologies for scanning and printing, production of counterfeit banknotes has become cheaper, easier, and more common. The proliferation of counterfeit banknotes causes loss to banks, traders, and individuals involved in financial transactions. Hence, it is inevitably needed that efficient and reliable techniques for detection of counterfeit banknotes should be developed. With the availability of powerful smartphones, it has become possible to perform complex computations and image processing related tasks on these phones. In addition to this, smartphone users have increased greatly and numbers continue to increase. This is a great motivating factor for researchers and developers to propose innovative mobile-based solutions. In this study, a novel technique for verification of Pakistani banknotes is developed, targeting smartphones with android platform. The proposed technique is based on statistical features, and surface roughness of a banknote, representing different properties of the banknote, such as paper material, printing ink, paper quality, and surface roughness. The selection of these features is motivated by the X-ray Diffraction (XRD and Scanning Electron Microscopy (SEM analysis of genuine and counterfeit banknotes. In this regard, two important areas of the banknote, i.e., serial number and flag portions were considered since these portions showed the maximum difference between genuine and counterfeit banknote. The analysis confirmed that genuine and counterfeit banknotes are very different in terms of the printing process, the ingredients used in preparation of banknotes, and the quality of the paper. After extracting the discriminative set of features, support vector machine is used for classification. The experimental results confirm the high accuracy of the proposed technique.

  5. Tree dimension in verification of constrained Horn clauses

    DEFF Research Database (Denmark)

    Kafle, Bishoksan; Gallagher, John Patrick; Ganty, Pierre

    2018-01-01

    In this paper, we show how the notion of tree dimension can be used in the verification of constrained Horn clauses (CHCs). The dimension of a tree is a numerical measure of its branching complexity and the concept here applies to Horn clause derivation trees. Derivation trees of dimension zero c...... algorithms using these constructions to decompose a CHC verification problem. One variation of this decomposition considers derivations of successively increasing dimension. The paper includes descriptions of implementations and experimental results....

  6. The design of verification regimes

    International Nuclear Information System (INIS)

    Gallagher, N.W.

    1991-01-01

    Verification of a nuclear agreement requires more than knowledge of relevant technologies and institutional arrangements. It also demands thorough understanding of the nature of verification and the politics of verification design. Arms control efforts have been stymied in the past because key players agreed to verification in principle, only to disagree radically over verification in practice. In this chapter, it is shown that the success and stability of arms control endeavors can be undermined by verification designs which promote unilateral rather than cooperative approaches to security, and which may reduce, rather than enhance, the security of both sides. Drawing on logical analysis and practical lessons from previous superpower verification experience, this chapter summarizes the logic and politics of verification and suggests implications for South Asia. The discussion begins by determining what properties all forms of verification have in common, regardless of the participants or the substance and form of their agreement. Viewing verification as the political process of making decisions regarding the occurrence of cooperation points to four critical components: (1) determination of principles, (2) information gathering, (3) analysis and (4) projection. It is shown that verification arrangements differ primarily in regards to how effectively and by whom these four stages are carried out

  7. Functional Verification of Enhanced RISC Processor

    OpenAIRE

    SHANKER NILANGI; SOWMYA L

    2013-01-01

    This paper presents design and verification of a 32-bit enhanced RISC processor core having floating point computations integrated within the core, has been designed to reduce the cost and complexity. The designed 3 stage pipelined 32-bit RISC processor is based on the ARM7 processor architecture with single precision floating point multiplier, floating point adder/subtractor for floating point operations and 32 x 32 booths multiplier added to the integer core of ARM7. The binary representati...

  8. Interferometry with flexible point source array for measuring complex freeform surface and its design algorithm

    Science.gov (United States)

    Li, Jia; Shen, Hua; Zhu, Rihong; Gao, Jinming; Sun, Yue; Wang, Jinsong; Li, Bo

    2018-06-01

    The precision of the measurements of aspheric and freeform surfaces remains the primary factor restrict their manufacture and application. One effective means of measuring such surfaces involves using reference or probe beams with angle modulation, such as tilted-wave-interferometer (TWI). It is necessary to improve the measurement efficiency by obtaining the optimum point source array for different pieces before TWI measurements. For purpose of forming a point source array based on the gradients of different surfaces under test, we established a mathematical model describing the relationship between the point source array and the test surface. However, the optimal point sources are irregularly distributed. In order to achieve a flexible point source array according to the gradient of test surface, a novel interference setup using fiber array is proposed in which every point source can be independently controlled on and off. Simulations and the actual measurement examples of two different surfaces are given in this paper to verify the mathematical model. Finally, we performed an experiment of testing an off-axis ellipsoidal surface that proved the validity of the proposed interference system.

  9. Trajectory Optimization of Spray Painting Robot for Complex Curved Surface Based on Exponential Mean Bézier Method

    Directory of Open Access Journals (Sweden)

    Wei Chen

    2017-01-01

    Full Text Available Automated tool trajectory planning for spray painting robots is still a challenging problem, especially for a large complex curved surface. This paper presents a new method of trajectory optimization for spray painting robot based on exponential mean Bézier method. The definition and the three theorems of exponential mean Bézier curves are discussed. Then a spatial painting path generation method based on exponential mean Bézier curves is developed. A new simple algorithm for trajectory optimization on complex curved surfaces is introduced. A golden section method is adopted to calculate the values. The experimental results illustrate that the exponential mean Bézier curves enhanced flexibility of the path planning, and the trajectory optimization algorithm achieved satisfactory performance. This method can also be extended to other applications.

  10. Final Report: Optimal Model Complexity in Geological Carbon Sequestration: A Response Surface Uncertainty Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ye [Univ. of Wyoming, Laramie, WY (United States)

    2018-01-17

    The critical component of a risk assessment study in evaluating GCS is an analysis of uncertainty in CO2 modeling. In such analyses, direct numerical simulation of CO2 flow and leakage requires many time-consuming model runs. Alternatively, analytical methods have been developed which allow fast and efficient estimation of CO2 storage and leakage, although restrictive assumptions on formation rock and fluid properties are employed. In this study, an intermediate approach is proposed based on the Design of Experiment and Response Surface methodology, which consists of using a limited number of numerical simulations to estimate a prediction outcome as a combination of the most influential uncertain site properties. The methodology can be implemented within a Monte Carlo framework to efficiently assess parameter and prediction uncertainty while honoring the accuracy of numerical simulations. The choice of the uncertain properties is flexible and can include geologic parameters that influence reservoir heterogeneity, engineering parameters that influence gas trapping and migration, and reactive parameters that influence the extent of fluid/rock reactions. The method was tested and verified on modeling long-term CO2 flow, non-isothermal heat transport, and CO2 dissolution storage by coupling two-phase flow with explicit miscibility calculation using an accurate equation of state that gives rise to convective mixing of formation brine variably saturated with CO2. All simulations were performed using three-dimensional high-resolution models including a target deep saline aquifer, overlying caprock, and a shallow aquifer. To evaluate the uncertainty in representing reservoir permeability, sediment hierarchy of a heterogeneous digital stratigraphy was mapped to create multiple irregularly shape stratigraphic models of decreasing geologic resolutions: heterogeneous (reference), lithofacies, depositional environment, and a (homogeneous) geologic formation. To ensure model

  11. Verification and Validation of The Tritium Transport Code TMAP7

    International Nuclear Information System (INIS)

    Glen R. Longhurst; James Ambrosek

    2004-01-01

    previously existing features for heat transfer, flows between enclosures, and chemical reactions within the enclosures have been retained, but the allowed problem size and complexity have been increased to take advantage of the greater memory and speed available on modern computers. One additional feature unique to TMAP7 is radioactive decay for both trapped and mobile species. Recently, TMAP7 has undergone verification and validation processes to ensure its performance in a wide variety of problems. This paper describes the use and new capabilities of TMAP7 and presents results of verification and validation testing

  12. A coupled remote sensing and the Surface Energy Balance with Topography Algorithm (SEBTA) to estimate actual evapotranspiration under complex terrain

    OpenAIRE

    Z. Q. Gao; C. S. Liu; W. Gao; N. B. Chang

    2010-01-01

    Evapotranspiration (ET) may be used as an ecological indicator to address the ecosystem complexity. The accurate measurement of ET is of great significance for studying environmental sustainability, global climate changes, and biodiversity. Remote sensing technologies are capable of monitoring both energy and water fluxes on the surface of the Earth. With this advancement, existing models, such as SEBAL, S_SEBI and SEBS, enable us to estimate the regional ET with limited temporal and spa...

  13. Surface-Induced Dissociation of Protein Complexes in a Hybrid Fourier Transform Ion Cyclotron Resonance Mass Spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Jing; Zhou, Mowei; Gilbert, Joshua D.; Wolff, Jeremy J.; Somogyi, Árpád; Pedder, Randall E.; Quintyn, Royston S.; Morrison, Lindsay J.; Easterling, Michael L.; Paša-Tolić, Ljiljana; Wysocki, Vicki H.

    2017-01-03

    Mass spectrometry continues to develop as a valuable tool in the analysis of proteins and protein complexes. In protein complex mass spectrometry studies, surface-induced dissociation (SID) has been successfully applied in quadrupole time-of-flight (Q-TOF) instruments. SID provides structural information on non-covalent protein complexes that is complementary to other techniques. However, the mass resolution of Q-TOF instruments can limit the information that can be obtained for protein complexes by SID. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) provides ultrahigh resolution and ultrahigh mass accuracy measurements. In this study, an SID device was designed and successfully installed in a hybrid FT-ICR instrument in place of the standard gas collision cell. The SID-FT-ICR platform has been tested with several protein complex systems (homooligomers, a heterooligomer, and a protein-ligand complex, ranging from 53 kDa to 85 kDa), and the results are consistent with data previously acquired on Q-TOF platforms, matching predictions from known protein interface information. SID fragments with the same m/z but different charge states are well-resolved based on distinct spacing between adjacent isotope peaks, and the addition of metal cations and ligands can also be isotopically resolved with the ultrahigh mass resolution available in FT-ICR.

  14. An initial research on solute migration model coupled with adsorption of surface complexation in groundwater

    International Nuclear Information System (INIS)

    Qian Tianwei; Chen Fanrong

    2003-01-01

    The influence of solution chemical action in groundwater on solute migration has attracted increasing public attention, especially adsorption action occurring on surface of solid phase and liquid phase, which has play a great role in solute migration. There are various interpretations on adsorption mechanism, in which surface complexion is one of successful hypothesis. This paper first establishes a geochemical model based on surface complexion and then coupled it with traditional advection-dispersion model to constitute a solute migration model, which can deal with surface complexion action. The simulated results fit very well with those obtained by the precursors, as compared with a published famous example, which indicates that the model set up by this paper is successful. (authors)

  15. Profile Curvature Derivative Surface used to characterize the complexity of the seafloor around St. John, USVI

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Profile curvature was calculated from the bathymetry surface for each raster cell using the ArcGIS 3D Analyst "Curvature" Tool. Profile curvature describes the rate...

  16. Rugosity Derivative Surface used to characterize the complexity of the seafloor around St. John, USVI

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Rugosity was calculated from the bathymetry surface for each cell using the "Rugosity" function in the Benthic Terrain Modeler toolbox (Jenness 2002, 2004; Wright et...

  17. Curvature Derivative Surface used to characterize the complexity of the seafloor around St. John, USVI

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Curvature was calculated from the bathymetry surface for each raster cell using the ArcGIS 3D Analyst "Curvature" Tool. Curvature describes the rate of change of...

  18. Slope Derivative Surface used to characterize the complexity of the seafloor around St. John, USVI

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Slope was calculated from the bathymetry surface for each raster cell using ArcGIS's Spatial Analyst 'Slope' Tool. Slope describes the maximum steepness of a terrain...

  19. Distorted Fingerprint Verification System

    Directory of Open Access Journals (Sweden)

    Divya KARTHIKAESHWARAN

    2011-01-01

    Full Text Available Fingerprint verification is one of the most reliable personal identification methods. Fingerprint matching is affected by non-linear distortion introduced in fingerprint impression during the image acquisition process. This non-linear deformation changes both the position and orientation of minutiae. The proposed system operates in three stages: alignment based fingerprint matching, fuzzy clustering and classifier framework. First, an enhanced input fingerprint image has been aligned with the template fingerprint image and matching score is computed. To improve the performance of the system, a fuzzy clustering based on distance and density has been used to cluster the feature set obtained from the fingerprint matcher. Finally a classifier framework has been developed and found that cost sensitive classifier produces better results. The system has been evaluated on fingerprint database and the experimental result shows that system produces a verification rate of 96%. This system plays an important role in forensic and civilian applications.

  20. Effect of complex alloying of powder materials on properties of laser melted surface layers

    International Nuclear Information System (INIS)

    Tesker, E.I.; Gur'ev, V.A.; Elistratov, V.S.; Savchenko, A.N.

    2001-01-01

    Quality and properties of laser melted surface layers produced using self-fluxing powder mixture of Ni-Cr-B-Si system and the same powders with enhanced Fe content alloyed with Co, Ti, Nb, Mo have been investigated. Composition of powder material is determined which does not cause of defect formation under laser melting and makes possible to produce a good mechanical and tribological properties of treated surface [ru

  1. Whisker growth: a new mechanism for helium blistering of surfaces in complex radiation environments

    International Nuclear Information System (INIS)

    McDonell, W.R.

    1978-01-01

    Implantation of helium concurrent with the generation of large numbers of displaced atoms in surface layers of materials exposed to 252 Cf α-particles and fission fragments produces a unique form of low temperature surface blistering. The purpose of this paper is to formulate a basis for the whisker-growth mechanism for helium blistering as an aid to the specification of conditions under which the mechanism might apply

  2. RESRAD-BUILD verification

    International Nuclear Information System (INIS)

    Kamboj, S.; Yu, C.; Biwer, B. M.; Klett, T.

    2002-01-01

    The results generated by the RESRAD-BUILD code (version 3.0) were verified with hand or spreadsheet calculations using equations given in the RESRAD-BUILD manual for different pathways. For verification purposes, different radionuclides--H-3, C-14, Na-22, Al-26, Cl-36, Mn-54, Co-60, Au-195, Ra-226, Ra-228, Th-228, and U-238--were chosen to test all pathways and models. Tritium, Ra-226, and Th-228 were chosen because of the special tritium and radon models in the RESRAD-BUILD code. Other radionuclides were selected to represent a spectrum of radiation types and energies. Verification of the RESRAD-BUILD code was conducted with an initial check of all the input parameters for correctness against their original source documents. Verification of the calculations was performed external to the RESRAD-BUILD code with Microsoft Excel to verify all the major portions of the code. In some cases, RESRAD-BUILD results were compared with those of external codes, such as MCNP (Monte Carlo N-particle) and RESRAD. The verification was conducted on a step-by-step basis and used different test cases as templates. The following types of calculations were investigated: (1) source injection rate, (2) air concentration in the room, (3) air particulate deposition, (4) radon pathway model, (5) tritium model for volume source, (6) external exposure model, (7) different pathway doses, and (8) time dependence of dose. Some minor errors were identified in version 3.0; these errors have been corrected in later versions of the code. Some possible improvements in the code were also identified

  3. Methods of Software Verification

    Directory of Open Access Journals (Sweden)

    R. E. Gurin

    2015-01-01

    Full Text Available This article is devoted to the problem of software verification (SW. Methods of software verification designed to check the software for compliance with the stated requirements such as correctness, system security and system adaptability to small changes in the environment, portability and compatibility, etc. These are various methods both by the operation process and by the way of achieving result. The article describes the static and dynamic methods of software verification and paid attention to the method of symbolic execution. In its review of static analysis are discussed and described the deductive method, and methods for testing the model. A relevant issue of the pros and cons of a particular method is emphasized. The article considers classification of test techniques for each method. In this paper we present and analyze the characteristics and mechanisms of the static analysis of dependencies, as well as their views, which can reduce the number of false positives in situations where the current state of the program combines two or more states obtained both in different paths of execution and in working with multiple object values. Dependences connect various types of software objects: single variables, the elements of composite variables (structure fields, array elements, the size of the heap areas, the length of lines, the number of initialized array elements in the verification code using static methods. The article pays attention to the identification of dependencies within the framework of the abstract interpretation, as well as gives an overview and analysis of the inference tools.Methods of dynamic analysis such as testing, monitoring and profiling are presented and analyzed. Also some kinds of tools are considered which can be applied to the software when using the methods of dynamic analysis. Based on the work a conclusion is drawn, which describes the most relevant problems of analysis techniques, methods of their solutions and

  4. Material integrity verification radar

    International Nuclear Information System (INIS)

    Koppenjan, S.K.

    1999-01-01

    The International Atomic Energy Agency (IAEA) has the need for verification of 'as-built' spent fuel-dry storage containers and other concrete structures. The IAEA has tasked the Special Technologies Laboratory (STL) to fabricate, test, and deploy a stepped-frequency Material Integrity Verification Radar (MIVR) system to nondestructively verify the internal construction of these containers. The MIVR system is based on previously deployed high-frequency, ground penetrating radar (GPR) systems that have been developed by STL for the U.S. Department of Energy (DOE). Whereas GPR technology utilizes microwave radio frequency energy to create subsurface images, MTVR is a variation for which the medium is concrete instead of soil. The purpose is to nondestructively verify the placement of concrete-reinforcing materials, pipes, inner liners, and other attributes of the internal construction. The MIVR system underwent an initial field test on CANDU reactor spent fuel storage canisters at Atomic Energy of Canada Limited (AECL), Chalk River Laboratories, Ontario, Canada, in October 1995. A second field test at the Embalse Nuclear Power Plant in Embalse, Argentina, was completed in May 1996. The DOE GPR also was demonstrated at the site. Data collection and analysis were performed for the Argentine National Board of Nuclear Regulation (ENREN). IAEA and the Brazilian-Argentine Agency for the Control and Accounting of Nuclear Material (ABACC) personnel were present as observers during the test. Reinforcing materials were evident in the color, two-dimensional images produced by the MIVR system. A continuous pattern of reinforcing bars was evident and accurate estimates on the spacing, depth, and size were made. The potential uses for safeguard applications were jointly discussed. The MIVR system, as successfully demonstrated in the two field tests, can be used as a design verification tool for IAEA safeguards. A deployment of MIVR for Design Information Questionnaire (DIQ

  5. Comparison of surface extraction techniques performance in computed tomography for 3D complex micro-geometry dimensional measurements

    DEFF Research Database (Denmark)

    Torralba, Marta; Jiménez, Roberto; Yagüe-Fabra, José A.

    2018-01-01

    micro-geometries as well (i.e., in the sub-mm dimensional range). However, there are different factors that may influence the CT process performance, being one of them the surface extraction technique used. In this paper, two different extraction techniques are applied to measure a complex miniaturized......The number of industrial applications of computed tomography (CT) for dimensional metrology in 100–103 mm range has been continuously increasing, especially in the last years. Due to its specific characteristics, CT has the potential to be employed as a viable solution for measuring 3D complex...... dental file by CT in order to analyze its contribution to the final measurement uncertainty in complex geometries at the mm to sub-mm scales. The first method is based on a similarity analysis: the threshold determination; while the second one is based on a gradient or discontinuity analysis: the 3D...

  6. The verification of operational surface wave forecast system in the South China Sea%南海海浪业务化数值预报系统检验

    Institute of Scientific and Technical Information of China (English)

    周水华; 俞胜宾; 梁昌霞; 冯伟忠; 吴迪生

    2012-01-01

    In order to estimate the Operational Surface Wave Forecast System of South China Sea Marine Fore-cast Center, SOA, by using the observational data during March-November in 2010 and 2011 in the South Chi-na Sea, the 24 h ,48 h, 72 h forecast result from the System is verified. The statistical results show that the predic-tion error of significant wave height and mean period is 24 h<48 h< 72h, and the average absolute error of signif-icant wave height forecasted in 24h, 48h, 72h is less than 0.5m. The average absolute error in the average period of 24h, 48h , 72 h is less than 0.8s. Meanwhile, the forecast error is significantly smaller in October and November than that in other months. Regression analysis revealed that the forecast value and the observed value exists in highly linear correlation relationship, and with the prediction time growth, the correlation is gradually decreasing, and overall the forecast values are larger than observed value. In conclusion, the system which forecast error is ac-ceptable and meets the basic requirements of operational forecasting. However, there are still larger gaps between this system and other similar system, such as ECMWF .%为检验南海海浪业务化数值预报系统的预报效果,利用2010年和2011年3-11月的观测资料,通过计算预报值和观测值的绝对误差、相对误差等统计参数和线性回归分析对南海海浪业务化数值预报系统进行检验.统计结果显示有效波高和平均周期的预报误差24 h<48 h<72 h,有效波高的24 h、48 h、72 h预报平均绝对误差小于0.5 m,平均周期的24 h、48 h、72 h预报平均绝对误差小于0.8 s;预报误差有明显的季节变化,10月和11月的预报误差显著小于其它各月;回归分析结果显示预报值与观测值存在中度高度线性相关关系,随着预报时效的增长相关度逐渐递减,预报值较观测值偏大.总体来说,该系统的预报误差在可接受的范围之内,满足业务化

  7. Bipodal surface organometallic complexes with surface N-donor ligands and application to the catalytic cleavage of C-H and C-C bonds in n -Butane

    KAUST Repository

    Bendjeriou-Sedjerari, Anissa

    2013-11-27

    We present a new generation of "true vicinal" functions well-distributed on the inner surface of SBA15: [(Sî - Si-NH 2)(≡Si-OH)] (1) and [(≡Si-NH2)2] (2). From these amine-modified SBA15s, two new well-defined surface organometallic species [(≡Si-NH-)(≡Si-O-)]Zr(CH2tBu) 2 (3) and [(≡Si-NH-)2]Zr(CH2tBu) 2 (4) have been obtained by reaction with Zr(CH2tBu) 4. The surfaces were characterized with 2D multiple-quantum 1H-1H NMR and infrared spectroscopies. Energy-filtered transmission electron microscopy (EFTEM), mass balance, and elemental analysis unambiguously proved that Zr(CH2tBu)4 reacts with these vicinal amine-modified surfaces to give mainly bipodal bis(neopentyl)zirconium complexes (3) and (4), uniformly distributed in the channels of SBA15. (3) and (4) react with hydrogen to give the homologous hydrides (5) and (6). Hydrogenolysis of n-butane catalyzed by these hydrides was carried out at low temperature (100 C) and low pressure (1 atm). While (6) exhibits a bis(silylamido)zirconium bishydride, [(≡Si-NH-)2]Zr(H) 2 (6a) (60%), and a bis(silylamido)silyloxozirconium monohydride, [(≡Si-NH-)2(≡Si-O-)]ZrH (6b) (40%), (5) displays a new surface organometallic complex characterized by an 1H NMR signal at 14.46 ppm. The latter is assigned to a (silylimido)(silyloxo)zirconium monohydride, [(≡Si-Nî)(≡Si-O-)]ZrH (5b) (30%), coexistent with a (silylamido)(silyloxo)zirconium bishydride, [(≡Si-NH-)(≡Si-O-)] Zr(H)2 (5a) (45%), and a silylamidobis(silyloxo)zirconium monohydride, [(≡Si-NH-)(≡Si-O-)2]ZrH (5c) (25%). Surprisingly, nitrogen surface ligands possess catalytic properties already encountered with silicon oxide surfaces, but interestingly, catalyst (5) with chelating [N,O] shows better activity than (6) with chelating [N,N]. © 2013 American Chemical Society.

  8. Bipodal surface organometallic complexes with surface N-donor ligands and application to the catalytic cleavage of C-H and C-C bonds in n -Butane

    KAUST Repository

    Bendjeriou-Sedjerari, Anissa; Azzi, Joachim; Abou-Hamad, Edy; Anjum, Dalaver H.; Pasha, Fahran A.; Huang, Kuo-Wei; Emsley, Lyndon; Basset, Jean-Marie

    2013-01-01

    We present a new generation of "true vicinal" functions well-distributed on the inner surface of SBA15: [(Sî - Si-NH 2)(≡Si-OH)] (1) and [(≡Si-NH2)2] (2). From these amine-modified SBA15s, two new well-defined surface organometallic species [(≡Si-NH-)(≡Si-O-)]Zr(CH2tBu) 2 (3) and [(≡Si-NH-)2]Zr(CH2tBu) 2 (4) have been obtained by reaction with Zr(CH2tBu) 4. The surfaces were characterized with 2D multiple-quantum 1H-1H NMR and infrared spectroscopies. Energy-filtered transmission electron microscopy (EFTEM), mass balance, and elemental analysis unambiguously proved that Zr(CH2tBu)4 reacts with these vicinal amine-modified surfaces to give mainly bipodal bis(neopentyl)zirconium complexes (3) and (4), uniformly distributed in the channels of SBA15. (3) and (4) react with hydrogen to give the homologous hydrides (5) and (6). Hydrogenolysis of n-butane catalyzed by these hydrides was carried out at low temperature (100 C) and low pressure (1 atm). While (6) exhibits a bis(silylamido)zirconium bishydride, [(≡Si-NH-)2]Zr(H) 2 (6a) (60%), and a bis(silylamido)silyloxozirconium monohydride, [(≡Si-NH-)2(≡Si-O-)]ZrH (6b) (40%), (5) displays a new surface organometallic complex characterized by an 1H NMR signal at 14.46 ppm. The latter is assigned to a (silylimido)(silyloxo)zirconium monohydride, [(≡Si-Nî)(≡Si-O-)]ZrH (5b) (30%), coexistent with a (silylamido)(silyloxo)zirconium bishydride, [(≡Si-NH-)(≡Si-O-)] Zr(H)2 (5a) (45%), and a silylamidobis(silyloxo)zirconium monohydride, [(≡Si-NH-)(≡Si-O-)2]ZrH (5c) (25%). Surprisingly, nitrogen surface ligands possess catalytic properties already encountered with silicon oxide surfaces, but interestingly, catalyst (5) with chelating [N,O] shows better activity than (6) with chelating [N,N]. © 2013 American Chemical Society.

  9. Modeling the Excess Cell Surface Stored in a Complex Morphology of Bleb-Like Protrusions.

    Directory of Open Access Journals (Sweden)

    Maryna Kapustina

    2016-03-01

    Full Text Available Cells transition from spread to rounded morphologies in diverse physiological contexts including mitosis and mesenchymal-to-amoeboid transitions. When these drastic shape changes occur rapidly, cell volume and surface area are approximately conserved. Consequently, the rounded cells are suddenly presented with a several-fold excess of cell surface whose area far exceeds that of a smooth sphere enclosing the cell volume. This excess is stored in a population of bleb-like protrusions (BLiPs, whose size distribution is shown by electron micrographs to be skewed. We introduce three complementary models of rounded cell morphologies with a prescribed excess surface area. A 2D Hamiltonian model provides a mechanistic description of how discrete attachment points between the cell surface and cortex together with surface bending energy can generate a morphology that satisfies a prescribed excess area and BLiP number density. A 3D random seed-and-growth model simulates efficient packing of BLiPs over a primary rounded shape, demonstrating a pathway for skewed BLiP size distributions that recapitulate 3D morphologies. Finally, a phase field model (2D and 3D posits energy-based constitutive laws for the cell membrane, nematic F-actin cortex, interior cytosol, and external aqueous medium. The cell surface is equipped with a spontaneous curvature function, a proxy for the cell surface-cortex couple, that is a priori unknown, which the model "learns" from the thin section transmission electron micrograph image (2D or the "seed and growth" model image (3D. Converged phase field simulations predict self-consistent amplitudes and spatial localization of pressure and stress throughout the cell for any posited stationary morphology target and cell compartment constitutive properties. The models form a general framework for future studies of cell morphological dynamics in a variety of biological contexts.

  10. Final Technical Report: Metal—Organic Surface Catalyst for Low-temperature Methane Oxidation: Bi-functional Union of Metal—Organic Complex and Chemically Complementary Surface

    Energy Technology Data Exchange (ETDEWEB)

    Tait, Steven L. [Indiana Univ., Bloomington, IN (United States)

    2016-10-01

    Stabilization and chemical control of transition metal centers is a critical problem in the advancement of heterogeneous catalysts to next-generation catalysts that exhibit high levels of selectivity, while maintaining strong activity and facile catalyst recycling. Supported metal nanoparticle catalysts typically suffer from having a wide range of metal sites with different coordination numbers and varying chemistry. This project is exploring new possibilities in catalysis by combining features of homogeneous catalysts with those of heterogeneous catalysts to develop new, bi-functional systems. The systems are more complex than traditional heterogeneous catalysts in that they utilize sequential active sites to accomplish the desired overall reaction. The interaction of metal—organic catalysts with surface supports and their interactions with reactants to enable the catalysis of critical reactions at lower temperatures are at the focus of this study. Our work targets key fundamental chemistry problems. How do the metal—organic complexes interact with the surface? Can those metal center sites be tuned for selectivity and activity as they are in the homogeneous system by ligand design? What steps are necessary to enable a cooperative chemistry to occur and open opportunities for bi-functional catalyst systems? Study of these systems will develop the concept of bringing together the advantages of heterogeneous catalysis with those of homogeneous catalysis, and take this a step further by pursuing the objective of a bi-functional system. The use of metal-organic complexes in surface catalysts is therefore of interest to create well-defined and highly regular single-site centers. While these are not likely to be stable in the high temperature environments (> 300 °C) typical of industrial heterogeneous catalysts, they could be applied in moderate temperature reactions (100-300 °C), made feasible by lowering reaction temperatures by better catalyst control. They also

  11. Directed assembly of functional light harvesting antenna complexes onto chemically patterned surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Escalante, Maryana [Biophysical Engineering Group, MESA and Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands); Maury, Pascale [Molecular Nanofabrication Group, MESA and Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands); Bruinink, Christiaan M [Molecular Nanofabrication Group, MESA and Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands); Werf, Kees van der [Biophysical Engineering Group, MESA and Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands); Olsen, John D [Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN (United Kingdom); Timney, John A [Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN (United Kingdom); Huskens, Jurriaan [Molecular Nanofabrication Group, MESA and Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands); Hunter, C Neil [Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN (United Kingdom); Subramaniam, Vinod [Biophysical Engineering Group, MESA and Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands); Otto, Cees [Biophysical Engineering Group, MESA and Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede (Netherlands)

    2008-01-16

    We report the directed assembly of the photosynthetic membrane proteins LH1 and LH2 isolated from the purple bacterium Rhodobacter sphaeroides onto chemically patterned substrates. Nanoimprint lithography was used to pattern discrete regions of amino- and fluoro-terminated or poly(ethylene glycol) self-assembled monolayers onto a glass substrate. Densely packed layers of assembled protein complexes were observed with atomic force microscopy. The protein complexes attached selectively to the amino-terminated regions by electrostatic interactions. Spectral images generated with a hybrid scanning probe and fluorescence microscope confirmed that the patterned proteins retained their native optical signatures.

  12. Directed assembly of functional light harvesting antenna complexes onto chemically patterned surfaces

    International Nuclear Information System (INIS)

    Escalante, Maryana; Maury, Pascale; Bruinink, Christiaan M; Werf, Kees van der; Olsen, John D; Timney, John A; Huskens, Jurriaan; Hunter, C Neil; Subramaniam, Vinod; Otto, Cees

    2008-01-01

    We report the directed assembly of the photosynthetic membrane proteins LH1 and LH2 isolated from the purple bacterium Rhodobacter sphaeroides onto chemically patterned substrates. Nanoimprint lithography was used to pattern discrete regions of amino- and fluoro-terminated or poly(ethylene glycol) self-assembled monolayers onto a glass substrate. Densely packed layers of assembled protein complexes were observed with atomic force microscopy. The protein complexes attached selectively to the amino-terminated regions by electrostatic interactions. Spectral images generated with a hybrid scanning probe and fluorescence microscope confirmed that the patterned proteins retained their native optical signatures

  13. A preliminary investigation of the applicability of surface complexation modeling to the understanding of transportation cask weeping

    International Nuclear Information System (INIS)

    Granstaff, V.E.; Chambers, W.B.; Doughty, D.H.

    1994-01-01

    A new application for surface complexation modeling is described. These models, which describe chemical equilibria among aqueous and adsorbed species, have typically been used for predicting groundwater transport of contaminants by modeling the natural adsorbents as various metal oxides. Our experiments suggest that this type of modeling can also explain stainless steel surface contamination and decontamination mechanisms. Stainless steel transportation casks, when submerged in a spent fuel storage pool at nuclear power stations, can become contaminated with radionuclides such as 137 Cs, 134 Cs, and 60 Co. Subsequent release or desorption of these contaminants under varying environmental conditions occasionally results in the phenomenon known as open-quotes cask weeping.close quotes We have postulated that contaminants in the storage pool adsorb onto the hydrous metal oxide surface of the passivated stainless steel and are subsequently released (by conversion from a fixed to a removable form) during transportation, due to varying environmental factors, such as humidity, road salt, dirt, and acid rain. It is well known that 304 stainless steel has a chromium enriched passive surface layer; thus its adsorption behavior should be similar to that of a mixed chromium/iron oxide. To help us interpret our studies of reversible binding of dissolved metals on stainless steel surfaces, we have studied the adsorption of Co +2 on Cr 2 O 3 . The data are interpreted using electrostatic surface complexation models. The FITEQL computer program was used to obtain the model binding constants and site densities from the experimental data. The MINTEQA2 computer speciation model was used, with the fitted constants, in an attempt to validate this approach

  14. Immobilization of rhodium complexes at thiolate monolayers on gold surfaces : Catalytic and structural studies

    NARCIS (Netherlands)

    Belser, T; Stöhr, Meike; Pfaltz, A

    2005-01-01

    Chiral rhodium-diphosphine complexes have been incorporated into self-assembled thiolate monolayers (SAMS) on gold colloids. Catalysts of this type are of interest because they combine properties of homogeneous and heterogeneous systems. In addition, it should be possible to influence the catalytic

  15. Wear of carbide inserts with complex surface treatment when milling nickel alloy

    Science.gov (United States)

    Fedorov, Sergey; Swe, Min Htet; Kapitanov, Alexey; Egorov, Sergey

    2018-03-01

    One of the effective ways of strengthening hard alloys is the creating structure layers on their surface with the gradient distribution of physical and mechanical properties between the wear-resistant coating and the base material. The article discusses the influence of the near-surface layer which is modified by low-energy high-current electron-beam alloying and the upper anti-friction layer in a multi-component coating on the wear mechanism of the replaceable multifaceted plates in the dry milling of the difficult to machine nickel alloys.

  16. Structural complexity and land-surface energy exchange along a gradient from arctic tundra to boreal forest

    Science.gov (United States)

    Thompson, C.; Beringer, J.; Chapin, F. S.; McGuire, A.D.

    2004-01-01

    Question: Current climate changes in the Alaskan Arctic, which are characterized by increases in temperature and length of growing season, could alter vegetation structure, especially through increases in shrub cover or the movement of treeline. These changes in vegetation structure have consequences for the climate system. What is the relationship between structural complexity and partitioning of surface energy along a gradient from tundra through shrub tundra to closed canopy forest? Location: Arctic tundra-boreal forest transition in the Alaskan Arctic. Methods: Along this gradient of increasing canopy complexity, we measured key vegetation characteristics, including community composition, biomass, cover, height, leaf area index and stem area index. We relate these vegetation characteristics to albedo and the partitioning of net radiation into ground, latent, and sensible heating fluxes. Results: Canopy complexity increased along the sequence from tundra to forest due to the addition of new plant functional types. This led to non-linear changes in biomass, cover, and height in the understory. The increased canopy complexity resulted in reduced ground heat fluxes, relatively conserved latent heat fluxes and increased sensible heat fluxes. The localized warming associated with increased sensible heating over more complex canopies may amplify regional warming, causing further vegetation change in the Alaskan Arctic.

  17. Tunable Complex Stability in Surface Molecular Recognition Mediated by Self-Complementary Quadruple Hydrogen Bonds

    NARCIS (Netherlands)

    Zou, S(han); Zhang, Zhihong; Forch, Renate; Knoll, Wolfgang; Schönherr, Holger; Vancso, Gyula J.

    2003-01-01

    We show that surfaces modified with asymmetric 2-ureido-4[1H]-pyrimidinone-hydroxyalkane disulfide adsorbates exhibit efficient and controllable self-complementary molecular recognition of the pyrimidinone moieties. Two novel asymmetric 2-ureido-4[1H]-pyrimidinone-hydroxyalkane disulfide adsorbates,

  18. Validation of solar radiation surfaces from MODIS and reanalysis data over topographically complex terrain

    Science.gov (United States)

    Todd A. Schroeder; Robbie Hember; Nicholas C. Coops; Shunlin Liang

    2009-01-01

    The magnitude and distribution of incoming shortwave solar radiation (SW) has significant influence on the productive capacity of forest vegetation. Models that estimate forest productivity require accurate and spatially explicit radiation surfaces that resolve both long- and short-term temporal climatic patterns and that account for topographic variability of the land...

  19. The complex dispersion relation of surface plasmon polaritons at gold/para-hexaphenylene interfaces

    DEFF Research Database (Denmark)

    Lemke, Christoph; Leißner, Till; Klick, Alwin

    2014-01-01

    Two-photon photoemission electron microscopy (2P-PEEM) is used to measure the real and imaginary part of the dispersion relation of surface plasmon polaritons at different interface systems. A comparison of calculated and measured dispersion data for a gold/vacuum interface demonstrates...

  20. Quantum money with classical verification

    Energy Technology Data Exchange (ETDEWEB)

    Gavinsky, Dmitry [NEC Laboratories America, Princeton, NJ (United States)

    2014-12-04

    We propose and construct a quantum money scheme that allows verification through classical communication with a bank. This is the first demonstration that a secure quantum money scheme exists that does not require quantum communication for coin verification. Our scheme is secure against adaptive adversaries - this property is not directly related to the possibility of classical verification, nevertheless none of the earlier quantum money constructions is known to possess it.

  1. Quantum money with classical verification

    International Nuclear Information System (INIS)

    Gavinsky, Dmitry

    2014-01-01

    We propose and construct a quantum money scheme that allows verification through classical communication with a bank. This is the first demonstration that a secure quantum money scheme exists that does not require quantum communication for coin verification. Our scheme is secure against adaptive adversaries - this property is not directly related to the possibility of classical verification, nevertheless none of the earlier quantum money constructions is known to possess it

  2. Inner-sphere, outer-sphere and ternary surface complexes: a TRLFS study of the sorption process of europium(III) onto smectite

    International Nuclear Information System (INIS)

    Stumpf, Th.; Fanghaenel, Th.; Bauer, A.; Kim, J.I.

    2002-01-01

    The surface sorption process of Eu(III) onto smectite was investigated by TRLFS in the trace concentration range. With increasing pH the formation of an inner-sphere Eu(III) surface complex was observed. The differences in the spectra and the fluorescence emission lifetimes of the surface sorbed Eu(III) in presence and absence of carbonate indicate the formation of ternary clay/Eu(III)/carbonate complexes /1/. (orig.)

  3. Scalable Techniques for Formal Verification

    CERN Document Server

    Ray, Sandip

    2010-01-01

    This book presents state-of-the-art approaches to formal verification techniques to seamlessly integrate different formal verification methods within a single logical foundation. It should benefit researchers and practitioners looking to get a broad overview of the spectrum of formal verification techniques, as well as approaches to combining such techniques within a single framework. Coverage includes a range of case studies showing how such combination is fruitful in developing a scalable verification methodology for industrial designs. This book outlines both theoretical and practical issue

  4. A Practitioners Perspective on Verification

    Science.gov (United States)

    Steenburgh, R. A.

    2017-12-01

    NOAAs Space Weather Prediction Center offers a wide range of products and services to meet the needs of an equally wide range of customers. A robust verification program is essential to the informed use of model guidance and other tools by both forecasters and end users alike. In this talk, we present current SWPC practices and results, and examine emerging requirements and potential approaches to satisfy them. We explore the varying verification needs of forecasters and end users, as well as the role of subjective and objective verification. Finally, we describe a vehicle used in the meteorological community to unify approaches to model verification and facilitate intercomparison.

  5. Development and verification of the CATHENA GUI

    International Nuclear Information System (INIS)

    Chin, T.

    2008-01-01

    This paper presents the development and verification of a graphical user interface for CATHENA MOD-3.5d. The thermalhydraulic computer code CATHENA has been developed to simulate the physical behaviour of the hydraulic components in nuclear reactors and experimental facilities. A representation of the facility is developed as an ASCII text file and used by CATHENA to perform the simulation. The existing method of manual generation of idealizations of a physical system for performing thermal hydraulic analysis is complex, time-consuming and prone to errors. An overview is presented of the CATHENA GUI and its depiction of a CATHENA idealization through the manipulation of a visual collection of objects. The methodologies and rigour involved in the verification of the CATHENA GUI will be discussed. (author)

  6. Structural characterization and Hirshfeld surface analysis of a CoII complex with imidazo[1,2-a]pyridine

    Directory of Open Access Journals (Sweden)

    Saikat Kumar Seth

    2018-05-01

    Full Text Available A new mononuclear tetrahedral CoII complex, dichloridobis(imidazo[1,2-a]pyridine-κN1cobalt(II, [CoCl2(C7H6N22], has been synthesized using a bioactive imidazopyridine ligand. X-ray crystallography reveals that the solid-state structure of the title complex exhibits both C—H...Cl and π–π stacking interactions in building supramolecular assemblies. Indeed, the molecules are linked by C—H...Cl interactions into a two-dimensional framework, with finite zero-dimensional dimeric units as building blocks, whereas π–π stacking plays a crucial role in building a supramolecular layered network. An exhaustive investigation of the diverse intermolecular interactions via Hirshfeld surface analysis enables contributions to the crystal packing of the title complex to be quantified. The fingerprint plots associated with the Hirshfeld surface clearly display each significant interaction involved in the structure, by quantifying them in an effective visual manner.

  7. Nucleolin inhibits Fas ligand binding and suppresses Fas-mediated apoptosis in vivo via a surface nucleolin-Fas complex.

    Science.gov (United States)

    Wise, Jillian F; Berkova, Zuzana; Mathur, Rohit; Zhu, Haifeng; Braun, Frank K; Tao, Rong-Hua; Sabichi, Anita L; Ao, Xue; Maeng, Hoyoung; Samaniego, Felipe

    2013-06-06

    Resistance to Fas-mediated apoptosis is associated with poor cancer outcomes and chemoresistance. To elucidate potential mechanisms of defective Fas signaling, we screened primary lymphoma cell extracts for Fas-associated proteins that would have the potential to regulate Fas signaling. An activation-resistant Fas complex selectively included nucleolin. We confirmed the presence of nucleolin-Fas complexes in B-cell lymphoma cells and primary tissues, and the absence of such complexes in B-lymphocytes from healthy donors. RNA-binding domain 4 and the glycine/arginine-rich domain of nucleolin were essential for its association with Fas. Nucleolin colocalized with Fas on the surface of B-cell lymphoma cells. Nucleolin knockdown sensitized BJAB cells to Fas ligand (FasL)-induced and Fas agonistic antibody-induced apoptosis through enhanced binding, suggesting that nucleolin blocks the FasL-Fas interaction. Mice transfected with nucleolin were protected from the lethal effects of agonistic anti-mouse Fas antibody (Jo2) and had lower rates of hepatocyte apoptosis, compared with vector and a non-Fas-binding mutant of nucleolin. Our results show that cell surface nucleolin binds Fas, inhibits ligand binding, and thus prevents induction of Fas-mediated apoptosis in B-cell lymphomas and may serve as a new therapeutic target.

  8. Development and Verification of Smoothed Particle Hydrodynamics Code for Analysis of Tsunami near NPP

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Young Beom; Kim, Eung Soo [Seoul National Univ., Seoul (Korea, Republic of)

    2014-10-15

    It becomes more complicated when considering the shape and phase of the ground below the seawater. Therefore, some different attempts are required to precisely analyze the behavior of tsunami. This paper introduces an on-going activities on code development in SNU based on an unconventional mesh-free fluid analysis method called Smoothed Particle Hydrodynamics (SPH) and its verification work with some practice simulations. This paper summarizes the on-going development and verification activities on Lagrangian mesh-free SPH code in SNU. The newly developed code can cover equation of motions and heat conduction equation so far, and verification of each models is completed. In addition, parallel computation using GPU is now possible, and GUI is also prepared. If users change input geometry or input values, they can simulate for various conditions geometries. A SPH method has large advantages and potential in modeling of free surface, highly deformable geometry and multi-phase problems that traditional grid-based code has difficulties in analysis. Therefore, by incorporating more complex physical models such as turbulent flow, phase change, two-phase flow, and even solid mechanics, application of the current SPH code is expected to be much more extended including molten fuel behaviors in the sever accident.

  9. Carborane-beta-cyclodextrin complexes as a supramolecular connector for bioactive surfaces

    Czech Academy of Sciences Publication Activity Database

    Neirynck, P.; Schimer, Jiří; Jonkheijm, P.; Milroy, L. G.; Cígler, Petr; Brunsveld, L.

    2015-01-01

    Roč. 3, č. 4 (2015), s. 539-545 ISSN 2050-750X R&D Projects: GA MŠk(CZ) LH11027 Institutional support: RVO:61388963 Keywords : beta-cyclodextrine/carborane host-guest system * supramolecular chemistry * bioactive surfaces Subject RIV: CD - Macromolecular Chemistry Impact factor: 4.872, year: 2015 http://pubs.rsc.org/en/content/articlepdf/2015/tb/c4tb01489h

  10. Complex surface deformation of Akutan volcano, Alaska revealed from InSAR time series

    Science.gov (United States)

    Wang, Teng; DeGrandpre, Kimberly; Lu, Zhong; Freymueller, Jeffrey T.

    2018-02-01

    Akutan volcano is one of the most active volcanoes in the Aleutian arc. An intense swarm of volcano-tectonic earthquakes occurred across the island in 1996. Surface deformation after the 1996 earthquake sequence has been studied using Interferometric Synthetic Aperture Radar (InSAR), yet it is hard to determine the detailed temporal behavior and spatial extent of the deformation due to decorrelation and the sparse temporal sampling of SAR data. Atmospheric delay anomalies over Akutan volcano are also strong, bringing additional technical challenges. Here we present a time series InSAR analysis from 2003 to 2016 to reveal the surface deformation in more detail. Four tracks of Envisat data acquired from 2003 to 2010 and one track of TerraSAR-X data acquired from 2010 to 2016 are processed to produce high-resolution surface deformation, with a focus on studying two transient episodes of inflation in 2008 and 2014. For the TerraSAR-X data, the atmospheric delay is estimated and removed using the common-master stacking method. These derived deformation maps show a consistently uplifting area on the northeastern flank of the volcano. From the TerraSAR-X data, we quantify the velocity of the subsidence inside the caldera to be as high as 10 mm/year, and identify another subsidence area near the ground cracks created during the 1996 swarm.

  11. Simulation of tracer dispersion from elevated and surface releases in complex terrain

    Science.gov (United States)

    Hernández, J. F.; Cremades, L.; Baldasano, J. M.

    A new version of an advanced mesoscale dispersion modeling system for simulating passive air pollutant dispersion in the real atmospheric planetary boundary layer (PBL), is presented. The system comprises a diagnostic mass-consistent meteorological model and a Lagrangian particle dispersion model (LADISMO). The former version of LADISMO, developed according to Zannetti (Air pollution modelling, 1990), was based on the Monte Carlo technique and included calculation of higher-order moments of vertical random forcing for convective conditions. Its ability to simulate complex flow dispersion has been stated in a previous paper (Hernández et al. 1995, Atmospheric Environment, 29A, 1331-1341). The new version follows Thomson's scheme (1984, Q. Jl Roy. Met. Soc.110, 1107-1120). It is also based on Langevin equation and follows the ideas given by Brusasca et al. (1992, Atmospheric Environment26A, 707-723) and Anfossi et al. (1992, Nuovo Cemento 15c, 139-158). The model is used to simulate the dispersion and predict the ground level concentration (g.l.c.) of a tracer (SF 6) released from both an elevated source ( case a) and a ground level source ( case b) in a highly complex mountainous terrain during neutral and synoptically dominated conditions ( case a) and light and apparently stable conditions ( case b). The last case is considered as being a specially difficult task to simulate. In fact, few works have reported situations with valley drainage flows in complex terrains and real stable atmospheric conditions with weak winds. The model assumes that nearly calm situations associated to strong stability and air stagnation, make the lowest layers of PBL poorly diffusive (Brusasca et al., 1992, Atmospheric Environment26A, 707-723). Model results are verified against experimental data from Guardo-90 tracer experiments, an intensive field campaign conducted in the Carrion river valley (Northern Spain) to study atmospheric diffusion within a steep walled valley in mountainous

  12. Survey on Offline Finger Print Verification System

    NARCIS (Netherlands)

    Suman, R.; Kaur, R.

    2012-01-01

    The fingerprint verification, means where "verification" implies a user matching a fingerprint against a single fingerprint associated with the identity that the user claims. Biometrics can be classified into two types Behavioral (signature verification, keystroke dynamics, etc.) And Physiological

  13. Analysis of progression of fatigue conditions in biceps brachii muscles using surface electromyography signals and complexity based features.

    Science.gov (United States)

    Karthick, P A; Makaram, Navaneethakrishna; Ramakrishnan, S

    2014-01-01

    Muscle fatigue is a neuromuscular condition where muscle performance decreases due to sustained or intense contraction. It is experienced by both normal and abnormal subjects. In this work, an attempt has been made to analyze the progression of muscle fatigue in biceps brachii muscles using surface electromyography (sEMG) signals. The sEMG signals are recorded from fifty healthy volunteers during dynamic contractions under well defined protocol. The acquired signals are preprocessed and segmented in to six equal parts for further analysis. The features, such as activity, mobility, complexity, sample entropy and spectral entropy are extracted from all six zones. The results are found showing that the extracted features except complexity feature have significant variations in differentiating non-fatigue and fatigue zone respectively. Thus, it appears that, these features are useful in automated analysis of various neuromuscular activities in normal and pathological conditions.

  14. Challenges in the Verification of Reinforcement Learning Algorithms

    Science.gov (United States)

    Van Wesel, Perry; Goodloe, Alwyn E.

    2017-01-01

    Machine learning (ML) is increasingly being applied to a wide array of domains from search engines to autonomous vehicles. These algorithms, however, are notoriously complex and hard to verify. This work looks at the assumptions underlying machine learning algorithms as well as some of the challenges in trying to verify ML algorithms. Furthermore, we focus on the specific challenges of verifying reinforcement learning algorithms. These are highlighted using a specific example. Ultimately, we do not offer a solution to the complex problem of ML verification, but point out possible approaches for verification and interesting research opportunities.

  15. Nonaqueous electrocatalytic water oxidation by a surface-bound Ru(bda)(L)₂ complex.

    Science.gov (United States)

    Sheridan, Matthew V; Sherman, Benjamin D; Wee, Kyung-Ryang; Marquard, Seth L; Gold, Alexander S; Meyer, Thomas J

    2016-04-21

    The rate of electrocatalytic water oxidation by the heterogeneous water oxidation catalyst [Ru(bda)(4-O(CH2)3P(O3H2)2-pyr)2], , (pyr = pyridine; bda = 2,2'-bipyridine-6,6'-dicarboxylate) on metal oxide surfaces is greatly enhanced relative to water as the solvent. In these experiments with propylene carbonate (PC) as the nonaqueous solvent, water is the limiting reagent. Mechanistic studies point to atom proton transfer (APT) as the rate limiting step in water oxidation catalysis.

  16. Surface complexation modeling of U(VI) sorption on GMZ bentonite in the presence of fulvic acid

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Jie [Lanzhou Univ. (China). Radiochemistry Laboratory; Ministry of Industry and Information Technology, Guangzhou (China). The 5th Electronics Research Inst.; Luo, Daojun [Ministry of Industry and Information Technology, Guangzhou (China). The 5th Electronics Research Inst.; Qiao, Yahua; Wang, Liang; Zhang, Chunming [Ministry of Environmental Protection, Beijing (China). Nuclear and Radiation Safety Center; Wu, Wangsuo [Lanzhou Univ. (China). Radiochemistry Laboratory; Ye, Yuanlv [Ministry of Environmental Protection, Beijing (China). Nuclear and Radiation Safety Center; Lanzhou Univ. (China). Radiochemistry Laboratory

    2017-03-01

    In this work, experiments and modeling for the interactions between uranyl ion and GMZ bentonite in the presence of fulvic acid are presented. The results demonstrated that FA is strongly bound to GMZ bentonite, and these molecules have a very large effect on the U(VI) sorption. The results also demonstrated that U(VI) sorption to GMZ bentonite in the presence and absence of sorbed FA can be well predicted by combining SHM and DLM. According to the model calculations, the nature of the interactions between FA with U(VI) at GMZ bentonite surface is mainly surface complex. The first attempt to simulate clay interaction with humus by the SHM model.

  17. Correlation and prediction of ion exchange equilibria on weak-acid resins by means of the surface complex formation model

    International Nuclear Information System (INIS)

    Horst, J.

    1988-11-01

    The present work summarizes investigations of the equilibrium of the exchange of protons, copper, zinc, calcium, magnesium and sodium ions on two weak-acid exchange resins in hydrochloric and carbonic acid bearing solutions at 25 0 C. The description of the state of equilibrium between resin and solution is based on the individual chemical equilibria which have to be adjusted simultaneously. The equilibrium in the liquid phase is described by the mass action law and the condition of electroneutrality using activity coefficients calculated according to the theory of Debye and Hueckel. The exchange equilibria are described by means of a surface complex formation model, which was developed by Davis, James and Leckie for activated aluminia and which has been applied to weak-acid resins. The model concept assumes the resin as a plane surface in which the functional groups are distributed uniformly. (orig./RB) [de

  18. Exploring the science of thinking independently together: Faraday Discussion Volume 204 - Complex Molecular Surfaces and Interfaces, Sheffield, UK, July 2017.

    Science.gov (United States)

    Samperi, M; Hirsch, B E; Diaz Fernandez, Y A

    2017-11-23

    The 2017 Faraday Discussion on Complex Molecular Surfaces and Interfaces brought together theoreticians and experimentalists from both physical and chemical backgrounds to discuss the relevant applied and fundamental research topics within the broader field of chemical surface analysis and characterization. Main discussion topics from the meeting included the importance of "disordered" two-dimensional (2D) molecular structures and the utility of kinetically trapped states. An emerging need for new experimental tools to address dynamics and kinetic pathways involved in self-assembled systems, as well as the future prospects and current limitations of in silico studies were also discussed. The following article provides a brief overview of the work presented and the challenges discussed during the meeting.

  19. A simple method for the preparation of difficult 99mTc complexes using surface adsorbed stannous ions

    International Nuclear Information System (INIS)

    Maddalena, D.J.; Snowdon, G.M.; Pojer, P.M.

    1987-01-01

    A simple new technique where stannous tin is adsorbed on the inner surface of plastic tubing and used to reduce ( 99m Tc) pertechnetate prior to labelling radiopharmaceuticals, has been evaluated, using some lipophillic and metal containing ligands. Complexes formed using the technique had good labelling efficiency and behaved the same in rat biodistribution studies as those prepared using conventional labelling methods. The labelling efficiency of the ligands was not related to their lipophillicity suggesting that this technique may be useful for labelling lipophillic and other difficult ligands such as those containing metals, which are incompatible with free stannous ions in solution. (M.E.L.) [es

  20. High-resolution MR imaging of triangular fibrocartilage complex (TFCC): comparison of microscopy coils and a conventional small surface coil

    Energy Technology Data Exchange (ETDEWEB)

    Yoshioka, Hiroshi [Department of Radiology, University of Tsukuba, Tsukuba (Japan); Department of Radiology, Brigham and Women' s Hospital, 75 Francis Street, 02115, Boston, MA (United States); Ueno, Teruko; Itai, Yuji [Department of Radiology, University of Tsukuba, Tsukuba (Japan); Tanaka, Toshikazu [Department of Orthopedic Surgery, Tsukuba Kinen Hospital, Tsukuba (Japan); Shindo, Masashi [Tsukuba University Hospital, Tsukuba (Japan)

    2003-10-01

    To compare MR images of the triangular fibrocartilage complex (TFCC) using microscopy coils with those using a conventional surface coil qualitatively and quantitatively. Proton density-weighted images and T2*-weighted images of the TFCC from ten normal volunteers were obtained with a conventional surface coil (C4 coil; 80 mm in diameter), a 47-mm microscopy surface coil and a 23-mm microscopy surface coil at 1.5 T. Qualitative image analysis of MR images with three coils was performed by two radiologists who assigned one of five numerical scores (0, nonvisualization; 1, poor; 2, average; 3, good; 4, excellent) for five TFCC components, which were disc proper, triangular ligament, meniscus homologue, ulnotriquetral and ulnolunate ligament. Quantitative analysis included the signal-to-noise ratio (S/N) of the disc proper of TFCC, the lunate cartilage, the lunate bone and the contrast-noise-ratio (C/N) between articular cartilage and disc proper or bone marrow were measured. All structures show higher scores qualitatively on MR with microscopy coils than those with a C4 coil, and the difference was significant with the exception of the ulnolunate ligament. MR with microscopy coils showed significantly higher S/N values than those with a conventional surface coil (P<0.05 to P<0.001). T2*-weighted images using microscopy coils showed significantly higher cartilage-disc proper C/N and cartilage-bone marrow C/N (P<0.01 to P<0.001). On proton density-weighted images, the C/N between cartilage and disc proper with two microscopy coils was significantly higher (P<0.01) than that with a conventional coil. High-resolution MR images of the normal wrist using microscopy coils were superior to those using a conventional surface coil qualitatively and quantitatively. High-resolution MR imaging with a microscopy coil would be a promising method to diagnose TFCC lesions. (orig.)

  1. Nitric oxide reduction in coal combustion: role of char surface complexes in heterogeneous reactions.

    Science.gov (United States)

    Arenillas, Ana; Rubiera, Fernando; Pis, José J

    2002-12-15

    Nitrogen oxides are one of the major environmental problems arising from fossil fuel combustion. Coal char is relatively rich in nitrogen, and so this is an important source of nitrogen oxides during coal combustion. However, due to its carbonaceous nature, char can also reduce NO through heterogeneous reduction. The objectives of this work were on one hand to compare NO emissions from coal combustion in two different types of equipment and on the other hand to study the influence of char surface chemistry on NO reduction. A series of combustion tests were carried out in two different scale devices: a thermogravimetric analyzer coupled to a mass spectrometer and an FTIR (TG-MS-FTIR) and a fluidized bed reactor with an on line battery of analyzers. The TG-MS-FTIR system was also used to perform a specific study on NO heterogeneous reduction reactions using chars with different surface chemistry. According to the results obtained, it can be said that the TG-MS-FTIR system provides valuable information about NO heterogeneous reduction and it can give good trends of the behavior in other combustion equipments (i.e., fluidized bed combustors). It has been also pointed out that NO-char interaction depends to a large extent on temperature. In the low-temperature range (800 degrees C), a different mechanism is involved in NO heterogeneous reduction, the nature of the carbon matrix being a key factor.

  2. Complex of spectral techniques for remote monitoring of oil spills on water surface

    International Nuclear Information System (INIS)

    Patsayeva, S.; Yuzhakov, V.; Barbini, R.; Fantini, R.; Frassanito, C.; Palucci, A.; Varlamov, V.

    1999-01-01

    Spectral properties of oil films on water surfaces were studied under laboratory conditions. A laser fluorosensor was used to measure fluorescence response; fluorescence decay measurements were also performed. Differences in decay time were noted for different mineral oils (ranging from 1 ns to 3.5 ns) and for refined oils (which ranged from 3.5 ns to 8 ns). Film thickness was estimated by calculating the wavelength -dependent absorption of the mineral oil. This new approach is independent of many accidental factors, and does not demand the a priori measured signal from clean water which is required by the more conventional method of suppression of the water Raman integral signal. These experiments confirmed the suitability of fluorescent spectroscopy as a very sensitive tool for oil detection and mapping, however, when applied to quantitative measurement or oil recognition in remote sensing, care must be taken to account for the factors influencing fluorescence response of mineral oil. It was also shown that fluorescence decay time is a useful technique to characterize the type of mineral oil spilled on water surface in that it provides a means to distinguish between the various types, using time-resolved spectra. 12 refs., 1 tab., 4 figs

  3. HDL to verification logic translator

    Science.gov (United States)

    Gambles, J. W.; Windley, P. J.

    1992-01-01

    The increasingly higher number of transistors possible in VLSI circuits compounds the difficulty in insuring correct designs. As the number of possible test cases required to exhaustively simulate a circuit design explodes, a better method is required to confirm the absence of design faults. Formal verification methods provide a way to prove, using logic, that a circuit structure correctly implements its specification. Before verification is accepted by VLSI design engineers, the stand alone verification tools that are in use in the research community must be integrated with the CAD tools used by the designers. One problem facing the acceptance of formal verification into circuit design methodology is that the structural circuit descriptions used by the designers are not appropriate for verification work and those required for verification lack some of the features needed for design. We offer a solution to this dilemma: an automatic translation from the designers' HDL models into definitions for the higher-ordered logic (HOL) verification system. The translated definitions become the low level basis of circuit verification which in turn increases the designer's confidence in the correctness of higher level behavioral models.

  4. Excitation of multipolar surface plasmon resonance in plasmonic nanoparticles by complex accelerating beams

    Science.gov (United States)

    Yang, Yang; Li, Jiafang; Li, Zhi-Yuan; Chen, Yue-Gang

    2015-07-01

    In this paper, through a vector-spherical harmonics approach, we investigate the optical spectra of plasmonic Au nanoparticles excited by two special accelerating beams: a non-paraxial Airy beam and a Bessel beam. We systematically analyze the impacts of the beam profile, phase, and helical wave front of the electromagnetic fields on the optical spectrum and the excitation of the surface plasmon resonance (SPR). We find that the high-order phase in the Airy beam would result in strong plasmonic oscillations in the optical spectra, while the cone angle and orbital angular momentum carried by the Bessel beam could be employed to engineer the plasmon modes excited in Au nanoparticles. Furthermore, the optical spectrum excited by a combined Airy-Bessel-Gauss beam is discussed. The study could help to deeply explore new ways to manipulate SPR in metal nanoparticles via the wave front engineering of optical beams for enhancing light-matter interaction and optical sensing performance.

  5. Excitation of multipolar surface plasmon resonance in plasmonic nanoparticles by complex accelerating beams

    International Nuclear Information System (INIS)

    Yang, Yang; Li, Jiafang; Li, Zhi-Yuan; Chen, Yue-Gang

    2015-01-01

    In this paper, through a vector-spherical harmonics approach, we investigate the optical spectra of plasmonic Au nanoparticles excited by two special accelerating beams: a non-paraxial Airy beam and a Bessel beam. We systematically analyze the impacts of the beam profile, phase, and helical wave front of the electromagnetic fields on the optical spectrum and the excitation of the surface plasmon resonance (SPR). We find that the high-order phase in the Airy beam would result in strong plasmonic oscillations in the optical spectra, while the cone angle and orbital angular momentum carried by the Bessel beam could be employed to engineer the plasmon modes excited in Au nanoparticles. Furthermore, the optical spectrum excited by a combined Airy–Bessel–Gauss beam is discussed. The study could help to deeply explore new ways to manipulate SPR in metal nanoparticles via the wave front engineering of optical beams for enhancing light–matter interaction and optical sensing performance. (paper)

  6. Verification and validation in computational fluid dynamics

    Science.gov (United States)

    Oberkampf, William L.; Trucano, Timothy G.

    2002-04-01

    Verification and validation (V&V) are the primary means to assess accuracy and reliability in computational simulations. This paper presents an extensive review of the literature in V&V in computational fluid dynamics (CFD), discusses methods and procedures for assessing V&V, and develops a number of extensions to existing ideas. The review of the development of V&V terminology and methodology points out the contributions from members of the operations research, statistics, and CFD communities. Fundamental issues in V&V are addressed, such as code verification versus solution verification, model validation versus solution validation, the distinction between error and uncertainty, conceptual sources of error and uncertainty, and the relationship between validation and prediction. The fundamental strategy of verification is the identification and quantification of errors in the computational model and its solution. In verification activities, the accuracy of a computational solution is primarily measured relative to two types of highly accurate solutions: analytical solutions and highly accurate numerical solutions. Methods for determining the accuracy of numerical solutions are presented and the importance of software testing during verification activities is emphasized. The fundamental strategy of validation is to assess how accurately the computational results compare with the experimental data, with quantified error and uncertainty estimates for both. This strategy employs a hierarchical methodology that segregates and simplifies the physical and coupling phenomena involved in the complex engineering system of interest. A hypersonic cruise missile is used as an example of how this hierarchical structure is formulated. The discussion of validation assessment also encompasses a number of other important topics. A set of guidelines is proposed for designing and conducting validation experiments, supported by an explanation of how validation experiments are different

  7. Chirality of weakly bound complexes: The potential energy surfaces for the hydrogen-peroxide−noble-gas interactions

    Energy Technology Data Exchange (ETDEWEB)

    Roncaratti, L. F., E-mail: lz@fis.unb.br; Leal, L. A.; Silva, G. M. de [Instituto de Física, Universidade de Brasília, 70910 Brasília (Brazil); Pirani, F. [Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia, 06123 Perugia (Italy); Aquilanti, V. [Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia, 06123 Perugia (Italy); Instituto de Física, Universidade Federal da Bahia, 40210 Salvador (Brazil); Gargano, R. [Instituto de Física, Universidade de Brasília, 70910 Brasília (Brazil); Departments of Chemistry and Physics, University of Florida, Quantum Theory Project, Gainesville, Florida 32611 (United States)

    2014-10-07

    We consider the analytical representation of the potential energy surfaces of relevance for the intermolecular dynamics of weakly bound complexes of chiral molecules. In this paper we study the H{sub 2}O{sub 2}−Ng (Ng=He, Ne, Ar, Kr, and Xe) systems providing the radial and the angular dependence of the potential energy surface on the relative position of the Ng atom. We accomplish this by introducing an analytical representation which is able to fit the ab initio energies of these complexes in a wide range of geometries. Our analysis sheds light on the role that the enantiomeric forms and the symmetry of the H{sub 2}O{sub 2} molecule play on the resulting barriers and equilibrium geometries. The proposed theoretical framework is useful to study the dynamics of the H{sub 2}O{sub 2} molecule, or other systems involving O–O and S–S bonds, interacting by non-covalent forces with atoms or molecules and to understand how the relative orientation of the O–H bonds changes along collisional events that may lead to a hydrogen bond formation or even to selectivity in chemical reactions.

  8. Removal of radioactive cesium from surface soils solidified using polyion complex. Rapid communication for decontamination test at Iitate-mura in Fukushima Prefecture

    International Nuclear Information System (INIS)

    Naganawa, Hirochika; Yanase, Nobuyuki; Mitamura, Hisayoshi; Nagano, Tetsushi; Yoshida, Zenko; Kumazawa, Noriyuki; Saitoh, Hiroshi; Kashima, Kaoru; Fukuda, Tatsuya; Tanaka, Shun-ichi

    2011-01-01

    We tried the decontamination of surface soils for three types of agricultural land at Nagadoro district of Iitate-mura (village) in Fukushima Prefecture, which is highly contaminated by deposits of radionuclides from the plume released from the Fukushima Daiichi nuclear power plant. The decontamination method consisted of the peeling of surface soils solidified using a polyion complex, which was formed from a salt solution of polycations and polyanions. Two types of polyion complex solution were applied to an upland field in a plastic greenhouse, a pasture, and a paddy field. The decontamination efficiency of the surface soils reached 90%, and dust release was effectively suppressed during the removal of surface soils. (author)

  9. Surface stabilized GMR nanorods of silver coated CrO2 synthesized via a polymer complex at ambient pressure

    International Nuclear Information System (INIS)

    Biswas, S.; Singh, G.P.; Ram, S.; Fecht, H.-J.

    2013-01-01

    Stable anisotropic nanorods of surface modified CrO 2 (∼18 nm diameter) with a correlated diamagnetic layer (2–3 nm thickness) of silver efficiently tailors useful magnetic and magnetoresistance (MR) properties. Essentially, it involves a core-shell structure that is developed by displacing part of Cr 4+ ions by Ag atoms on the CrO 2 surface (topotactic surface layer) via an etching reaction of a CrO 2 -polymer complex with Ag + ions in hot water followed by heating the dried sample at 300–400 °C in air. The stable Ag-layer so obtained in the form of a shell protects CrO 2 such that it no longer converts to Cr 2 O 3 in ambient pressure during the processing. X-ray diffractogram of the Rutile type tetragonal CrO 2 structure (lattice parameters a=0.4429 nm and c=0.2950 nm) includes weak peaks of a minority phase of an fcc-Ag (a=0.4086 nm). The silver surface layer, which manifests itself in a doublet of the 3d 5/2 and 3d 3/2 X-ray photoelectron bands of binding energies 368.46 eV and 374.48 eV, respectively, suppresses almost all Cr bands to appear in a measurable intensity. The sample exhibits a distinctly enhanced MR-value, e.g., (−) 7.6% at 77 K, than reported values in compacted CrO 2 powders or composites. Such a large MR-value in the Coulomb blockade regime ( 2 nanorods. - Highlights: • Synthesis and structural studies of a novel GMR material of Ag coated CrO 2 . • Tailoring useful GMR property in CrO 2 nanorods of controlled shape and anisotropy. • Enhanced GMR is explained in correlation to the surface structure of CrO 2 nanorods

  10. Verification of Simulation Tools

    International Nuclear Information System (INIS)

    Richard, Thierry

    2015-01-01

    Before qualifying a simulation tool, the requirements shall first be clearly identified, i.e.: - What type of study needs to be carried out? - What phenomena need to be modeled? This phase involves writing a precise technical specification. Once the requirements are defined, the most adapted product shall be selected from the various software options available on the market. Before using a particular version of a simulation tool to support the demonstration of nuclear safety studies, the following requirements shall be met. - An auditable quality assurance process complying with development international standards shall be developed and maintained, - A process of verification and validation (V and V) shall be implemented. This approach requires: writing a report and/or executive summary of the V and V activities, defining a validated domain (domain in which the difference between the results of the tools and those of another qualified reference is considered satisfactory for its intended use). - Sufficient documentation shall be available, - A detailed and formal description of the product (software version number, user configuration, other settings and parameters) in the targeted computing environment shall be available. - Source codes corresponding to the software shall be archived appropriately. When these requirements are fulfilled, the version of the simulation tool shall be considered qualified for a defined domain of validity, in a given computing environment. The functional verification shall ensure that: - the computer architecture of the tool does not include errors, - the numerical solver correctly represents the physical mathematical model, - equations are solved correctly. The functional verification can be demonstrated through certification or report of Quality Assurance. The functional validation shall allow the user to ensure that the equations correctly represent the physical phenomena in the perimeter of intended use. The functional validation can

  11. Complex source mechanisms of mining-induced seismic events - implications for surface effects

    Science.gov (United States)

    Orlecka-Sikora, B.; Cesca, S.; Lasocki, S.; Rudzinski, L.; Lizurek, L.; Wiejacz, P.; Urban, P.; kozlowska, M.

    2012-04-01

    The seismicity of Legnica-Głogów Copper District (LGCD) is induced by mining activities in three mines: Lubin, Rudna and Polkowice-Sieroszowice. Ground motion caused by strong tremors might affect local infrastructure. "Żelazny Most" tailings pond, the biggest structure of this type in Europe, is here under special concern. Due to surface objects protection, Rudna Mine has been running ground motion monitoring for several years. From June 2010 to June 2011 unusually strong and extensive surface impact has been observed for 6 mining tremors induced in one of Rudna mining sections. The observed peak ground acceleration (PGA) for both horizontal and vertical component were in or even beyond 99% confidence interval for prediction. The aim of this paper is analyze the reason of such unusual ground motion. On the basis of registrations from Rudna Mine mining seismological network and records from Polish Seismological Network held by the Institute of Geophysics Polish Academy of Sciences (IGF PAN), the source mechanisms of these 6 tremors were calculated using a time domain moment tensor inversion. Furthermore, a kinematic analysis of the seismic source was performed, in order to determine the rupture planes orientations and rupture directions. These results showed that in case of the investigated tremors, point source models and shear fault mechanisms, which are most often assumed in mining seismology, are invalid. All analyzed events indicate extended sources with non-shear mechanism. The rapture planes have small dip angles and the rupture starts at the tremors hypocenter and propagates in the direction opposite to the plane dip. The tensional component plays here also big role. These source mechanisms well explain such observed strong ground motion, and calculated synthetic PGA values well correlates with observed ones. The relationship between mining tremors were also under investigation. All subsequent tremors occurred in the area of increased stress due to

  12. Property-driven functional verification technique for high-speed vision system-on-chip processor

    Science.gov (United States)

    Nshunguyimfura, Victor; Yang, Jie; Liu, Liyuan; Wu, Nanjian

    2017-04-01

    The implementation of functional verification in a fast, reliable, and effective manner is a challenging task in a vision chip verification process. The main reason for this challenge is the stepwise nature of existing functional verification techniques. This vision chip verification complexity is also related to the fact that in most vision chip design cycles, extensive efforts are focused on how to optimize chip metrics such as performance, power, and area. Design functional verification is not explicitly considered at an earlier stage at which the most sound decisions are made. In this paper, we propose a semi-automatic property-driven verification technique. The implementation of all verification components is based on design properties. We introduce a low-dimension property space between the specification space and the implementation space. The aim of this technique is to speed up the verification process for high-performance parallel processing vision chips. Our experimentation results show that the proposed technique can effectively improve the verification effort up to 20% for the complex vision chip design while reducing the simulation and debugging overheads.

  13. Conformational Explosion: Understanding the Complexity of the Para-Dialkylbenzene Potential Energy Surfaces

    Science.gov (United States)

    Mishra, Piyush; Hewett, Daniel M.; Zwier, Timothy S.

    2017-06-01

    This talk focuses on the single-conformation spectroscopy of small-chain para-dialkylbenzenes. This work builds on previous studies from our group on long-chain n-alkylbenzenes that identified the first folded structure in octylbenzene. The dialkylbenzenes are representative of a class of molecules that are common components of coal and aviation fuel and are known to be present in vehicle exhaust. We bring the molecules para-diethylbenzene, para-dipropylbenzene and para-dibutylbenzene into the gas phase and cool the molecules in a supersonic expansion. The jet-cooled molecules are then interrogated using laser-induced fluorescence excitation, fluorescence dip IR spectroscopy (FDIRS) and dispersed fluorescence. The LIF spectra in the S_{0}-S_{1} origin region show dramatic increases in the number of resolved transitions with increasing length of alkyl chains, reflecting an explosion in the number of unique low-energy conformations formed when two independent alkyl chains are present. Since the barriers to isomerization of the alkyl chain are similar in size, this results in an 'egg carton' shape to the potential energy surface. We use a combination of electronic frequency shift and alkyl CH stretch infrared spectra to generate a consistent set of conformational assignments.

  14. Sorption of phosphate onto calcite; results from batch experiments and surface complexation modeling

    DEFF Research Database (Denmark)

    Sø, Helle Ugilt; Postma, Dieke; Jakobsen, Rasmus

    2011-01-01

    The adsorption of phosphate onto calcite was studied in a series of batch experiments. To avoid the precipitation of phosphate-containing minerals the experiments were conducted using a short reaction time (3h) and low concentrations of phosphate (⩽50μM). Sorption of phosphate on calcite was stud......The adsorption of phosphate onto calcite was studied in a series of batch experiments. To avoid the precipitation of phosphate-containing minerals the experiments were conducted using a short reaction time (3h) and low concentrations of phosphate (⩽50μM). Sorption of phosphate on calcite...... of a high degree of super-saturation with respect to hydroxyapatite (SIHAP⩽7.83). The amount of phosphate adsorbed varied with the solution composition, in particular, adsorption increases as the CO32- activity decreases (at constant pH) and as pH increases (at constant CO32- activity). The primary effect...... of ionic strength on phosphate sorption onto calcite is its influence on the activity of the different aqueous phosphate species. The experimental results were modeled satisfactorily using the constant capacitance model with >CaPO4Ca0 and either >CaHPO4Ca+ or >CaHPO4- as the adsorbed surface species...

  15. Adaptive Robust Online Constructive Fuzzy Control of a Complex Surface Vehicle System.

    Science.gov (United States)

    Wang, Ning; Er, Meng Joo; Sun, Jing-Chao; Liu, Yan-Cheng

    2016-07-01

    In this paper, a novel adaptive robust online constructive fuzzy control (AR-OCFC) scheme, employing an online constructive fuzzy approximator (OCFA), to deal with tracking surface vehicles with uncertainties and unknown disturbances is proposed. Significant contributions of this paper are as follows: 1) unlike previous self-organizing fuzzy neural networks, the OCFA employs decoupled distance measure to dynamically allocate discriminable and sparse fuzzy sets in each dimension and is able to parsimoniously self-construct high interpretable T-S fuzzy rules; 2) an OCFA-based dominant adaptive controller (DAC) is designed by employing the improved projection-based adaptive laws derived from the Lyapunov synthesis which can guarantee reasonable fuzzy partitions; 3) closed-loop system stability and robustness are ensured by stable cancelation and decoupled adaptive compensation, respectively, thereby contributing to an auxiliary robust controller (ARC); and 4) global asymptotic closed-loop system can be guaranteed by AR-OCFC consisting of DAC and ARC and all signals are bounded. Simulation studies and comprehensive comparisons with state-of-the-arts fixed- and dynamic-structure adaptive control schemes demonstrate superior performance of the AR-OCFC in terms of tracking and approximation accuracy.

  16. Gallium sorption on montmorillonite and illite colloids: Experimental study and modelling by ionic exchange and surface complexation

    International Nuclear Information System (INIS)

    Benedicto, Ana; Degueldre, Claude; Missana, Tiziana

    2014-01-01

    Highlights: • Ga sorption onto illite and montmorillonite was studied and modelled for the first time. • The developed sorption model was able to well explain Ga sorption in both clays. • Number of free parameters was reduced applying the linear free energy relationship. • Cationic exchange dominate sorption at pH < 4.5; surface complexation at higher pH. - Abstract: The migration of metals as gallium (Ga) in the environment is highly influenced by their sorption on clay minerals, as montmorillonite and illite. Given the increased usage of gallium in the industry and the medicine, the Ga-associated waste may result in environmental problems. Ga sorption experiments were carried out on montmorillonite and illite colloids in a wide range of pH, ionic strength and Ga concentration. A Ga sorption model was developed combining ionic exchange and surface complexation on the edge sites (silanol and aluminol-like) of the clay sheets. The complexation constants were estimated as far as possible from the Ga hydrolysis constants applying the linear free energy relationship (LFER), which allowed to reduce the number of free parameters in the model. The Ga sorption behaviour was very similar on illite and montmorillonite: decreasing tendency with pH and dependency on ionic strength at very acidic conditions. The experimental data modelling suggests that the Ga sorption reactions avoid the Ga precipitation, which is predicted in absence of clay colloids between pH 3.5 and 5.5. Assuming this hypothesis, clay colloids would affect Ga aqueous speciation, preventing precipitation in favour of sorption. Ga sorption on montmorillonite and illite can be explained on the basis of three main reactions: Ga 3+ exchange at very acidic conditions (pH < ∼3.8); Ga(OH) 4 - complexation on protonated weak sites in acidic-neutral conditions (between pH ∼5.2 and pH ∼7.9); and Ga(OH) 3 complexation on strong sites at basic conditions (pH > ∼7.9)

  17. Dosimetric verification of IMRT plans

    International Nuclear Information System (INIS)

    Bulski, W.; Cheimicski, K.; Rostkowska, J.

    2012-01-01

    Intensity modulated radiotherapy (IMRT) is a complex procedure requiring proper dosimetric verification. IMRT dose distributions are characterized by steep dose gradients which enable to spare organs at risk and allow for an escalation of the dose to the tumor. They require large number of radiation beams (sometimes over 10). The fluence measurements for individual beams are not sufficient for evaluation of the total dose distribution and to assure patient safety. The methods used at the Centre of Oncology in Warsaw are presented. In order to measure dose distributions in various cross-sections the film dosimeters were used (radiographic Kodak EDR2 films and radiochromic Gafchromic EBT films). The film characteristics were carefully examined. Several types of tissue equivalent phantoms were developed. A methodology of comparing measured dose distributions against the distributions calculated by treatment planning systems (TPS) was developed and tested. The tolerance level for this comparison was set at 3% difference in dose and 3 mm in distance to agreement. The so called gamma formalism was used. The results of these comparisons for a group of over 600 patients are presented. Agreement was found in 87 % of cases. This film dosimetry methodology was used as a benchmark to test and validate the performance of commercially available 2D and 3D matrices of detectors (ionization chambers or diodes). The results of these validations are also presented. (authors)

  18. Shift Verification and Validation

    Energy Technology Data Exchange (ETDEWEB)

    Pandya, Tara M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Evans, Thomas M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Davidson, Gregory G [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Johnson, Seth R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Godfrey, Andrew T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-09-07

    This documentation outlines the verification and validation of Shift for the Consortium for Advanced Simulation of Light Water Reactors (CASL). Five main types of problems were used for validation: small criticality benchmark problems; full-core reactor benchmarks for light water reactors; fixed-source coupled neutron-photon dosimetry benchmarks; depletion/burnup benchmarks; and full-core reactor performance benchmarks. We compared Shift results to measured data and other simulated Monte Carlo radiation transport code results, and found very good agreement in a variety of comparison measures. These include prediction of critical eigenvalue, radial and axial pin power distributions, rod worth, leakage spectra, and nuclide inventories over a burn cycle. Based on this validation of Shift, we are confident in Shift to provide reference results for CASL benchmarking.

  19. Online fingerprint verification.

    Science.gov (United States)

    Upendra, K; Singh, S; Kumar, V; Verma, H K

    2007-01-01

    As organizations search for more secure authentication methods for user access, e-commerce, and other security applications, biometrics is gaining increasing attention. With an increasing emphasis on the emerging automatic personal identification applications, fingerprint based identification is becoming more popular. The most widely used fingerprint representation is the minutiae based representation. The main drawback with this representation is that it does not utilize a significant component of the rich discriminatory information available in the fingerprints. Local ridge structures cannot be completely characterized by minutiae. Also, it is difficult quickly to match two fingerprint images containing different number of unregistered minutiae points. In this study filter bank based representation, which eliminates these weakness, is implemented and the overall performance of the developed system is tested. The results have shown that this system can be used effectively for secure online verification applications.

  20. Surface properties of self-assembled monolayer films of tetra-substituted cobalt, iron and manganese alkylthio phthalocyanine complexes

    Energy Technology Data Exchange (ETDEWEB)

    Akinbulu, Isaac Adebayo; Khene, Samson [Department of Chemistry, Rhodes University, Grahamstown 6140 (South Africa); Nyokong, Tebello, E-mail: t.nyokong@ru.ac.z [Department of Chemistry, Rhodes University, Grahamstown 6140 (South Africa)

    2010-09-30

    Self-assembled monolayer (SAM) films of iron (SAM-1), cobalt (SAM-2) and manganese (SAM-3) phthalocyanine complexes, tetra-substituted with diethylaminoethanethio at the non-peripheral positions, were formed on gold electrode in dimethylformamide (DMF). Electrochemical, impedimentary and surface properties of the SAM films were investigated. Cyclic voltammetry was used to investigate the electrochemical properties of the films. Ability of the films to inhibit common faradaic processes on bare gold surface (gold oxidation, solution redox chemistry of [Fe(H{sub 2}O){sub 6}]{sup 3+}/[Fe(H{sub 2}O){sub 6}]{sup 2+} and underpotential deposition (UDP) of copper) was investigated. Electrochemical impedance spectroscopy (EIS), using [Fe(CN){sub 6}]{sup 3-/4-} redox process as a probe, offered insights into the electrical properties of the films/electrode interfaces. Surface properties of the films were probed using atomic force microscopy (AFM) and scanning electron microscopy (SEM). The films were employed for the electrocatalytic oxidation of the pesticide, carbofuran. Electrocatalysis was evidenced from enhanced current signal and less positive oxidation potential of the pesticide on each film, relative to that observed on the bare gold electrode. Mechanism of electrocatalytic oxidation of the pesticide was studied using rotating disc electrode voltammetry.

  1. Conformational explosion: Understanding the complexity of short chain para-dialkylbenzene potential energy surfaces

    Science.gov (United States)

    Mishra, Piyush; Hewett, Daniel M.; Zwier, Timothy S.

    2018-05-01

    The single-conformation ultraviolet and infrared spectroscopy of three short-chain para-dialkylbenzenes (para-diethylbenzene, para-dipropylbenzene, and para-dibutylbenzene) is reported for the jet-cooled, isolated molecules. The present study builds off previous work on single-chain n-alkylbenzenes, where an anharmonic local mode Hamiltonian method was developed to account for stretch-bend Fermi resonance in the alkyl CH stretch region [D. P. Tabor et al., J. Chem. Phys. 144, 224310 (2016)]. The jet-cooled molecules are interrogated using laser-induced fluorescence (LIF) excitation, fluorescence dip infrared spectroscopy, and dispersed fluorescence. The LIF spectra in the S1 ← S0 origin region show a dramatic increase in the number of resolved transitions with increasing length of the alkyl chains, reflecting an explosion in the number of unique low-energy conformations formed when two independent alkyl chains are present. Since the barriers to isomerization of the alkyl chain are similar in size, this results in an "egg carton" shaped potential energy surface. A combination of electronic frequency shift and alkyl CH stretch infrared spectra is used to generate a consistent set of conformational assignments. Using these experimental techniques in conjunction with computational methods, subsets of origin transitions in the LIF excitation spectrum can be classified into different conformational families. Two conformations are resolved in para-diethylbenzene, seven in para-dipropylbenzene, and about nineteen in para-dibutylbenzene. These chains are largely independent of each other as there are no new single-chain conformations induced by the presence of a second chain. A cursory LIF excitation scan of para-dioctylbenzene shows a broad congested spectrum at frequencies consistent with interactions of alkyl chains with the phenyl π cloud.

  2. Complex Indigenous Organic Matter Embedded in Apollo 17 Volcanic Black Glass Surface Deposits

    Science.gov (United States)

    Thomas-Keprta, Kathie L.; Clemett, S. J.; Ross, D. K.; Le, L.; Rahman, Z.; Gonzalez, C.; McKay, D. S.; Gibson, E. K.

    2013-01-01

    Papers presented at the first Lunar Science Conference [1] and those published in the subsequent Science Moon Issue [2] reported the C content of Apollo II soils, breccias, and igneous rocks as rang-ing from approx.50 to 250 parts per million (ppm). Later Fegley & Swindle [3] summarized the C content of bulk soils from all the Apollo missions as ranging from 2.5 (Apollo 15) to 280 ppm (Apollo 16) with an overall average of 124+/- 45 ppm. These values are unexpectedly low given that multiple processes should have contributed (and in some cases continue to contribute) to the lunar C inventory. These include exogenous accretion of cometary and asteroidal dust, solar wind implantation, and synthesis of C-bearing species during early lunar volcanism. We estimate the contribution of C from exogenous sources alone is approx.500 ppm, which is approx.4x greater than the reported average. While the assessm ent of indigenous organic matter (OM) in returned lunar samples was one of the primary scientific goals of the Apollo program, extensive analysis of Apollo samples yielded no evidence of any significant indigenous organic species. Furthermore, with such low concentrations of OM reported, the importance of discriminating indigenous OM from terrestrial contamination (e.g., lunar module exhaust, sample processing and handling) became a formidable task. After more than 40 years, with the exception of CH4 [5-7], the presence of indigenous lunar organics still remains a subject of considerable debate. We report for the first time the identification of arguably indigenous OM present within surface deposits of black glass grains collected on the rim of Shorty crater during the Apollo 17 mission by astronauts Eugene Cernan and Harrison Schmitt.

  3. Near-surface Imaging of a Maya Plaza Complex using Ground-Penetrating Radar

    Science.gov (United States)

    Aitken, J. A.; Stewart, R. R.

    2005-05-01

    The University of Calgary has conducted a number of ground-penetrating radar surveys at a Maya archaeological site. The purpose of the study is to discern the near-surface structure and stratigraphy of the plaza, and to assist the archaeologists in focusing their excavation efforts. The area of study is located in Belize, Central America at the ancient Maya site of Maax Na. Flanked by structures believed to be temples to the north and west, the archaeologists were interested in determining how many levels of plaza were built and if there was any discernable slope to the plaza. Over the last three years, both 2-D lines and 3-D grids were acquired at the plaza using a Sensors and Software Inc. Noggin Plus system at an antenna frequency of 250 MHz. The processing flow consisted of the application of gain, various filtering techniques and a diffraction stack migration using Reflexw. Interpolation of the gridded data was investigated using simple averaging, F-K migration, pre-stack migration and inversion techniques. As this study has evolved over different field seasons, measured velocities appear to change with the saturation level of the shallow section. Velocity measurements ranged from 0.058 - .106 m/ns during the wet conditions encountered in 2002 and 2004, while velocities of 1.22 - 1.40 m/ns were measured in the drought of 2003. The GPR images to date indicate continuous and interpretable images of the subsurface, showing evidence of structure, discontinuities and amplitude variations. A number of interesting anomalies have been identified, and prioritized for excavation.

  4. Design verification for large reprocessing plants (Proposed procedures)

    International Nuclear Information System (INIS)

    Rolandi, G.

    1988-07-01

    In the 1990s, four large commercial reprocessing plants will progressively come into operation: If an effective and efficient safeguards system is to be applied to these large and complex plants, several important factors have to be considered. One of these factors, addressed in the present report, concerns plant design verification. Design verification provides an overall assurance on plant measurement data. To this end design verification, although limited to the safeguards aspects of the plant, must be a systematic activity, which starts during the design phase, continues during the construction phase and is particularly performed during the various steps of the plant's commissioning phase. The detailed procedures for design information verification on commercial reprocessing plants must be defined within the frame of the general provisions set forth in INFCIRC/153 for any type of safeguards related activities and specifically for design verification. The present report is intended as a preliminary contribution on a purely technical level, and focusses on the problems within the Agency. For the purpose of the present study the most complex case was assumed: i.e. a safeguards system based on conventional materials accountancy, accompanied both by special input and output verification and by some form of near-real-time accountancy involving in-process inventory taking, based on authenticated operator's measurement data. C/S measures are also foreseen, where necessary to supplement the accountancy data. A complete ''design verification'' strategy comprehends: informing the Agency of any changes in the plant system which are defined as ''safeguards relevant''; ''reverifying by the Agency upon receiving notice from the Operator on any changes, on ''design information''. 13 refs

  5. Improved verification methods for safeguards verifications at enrichment plants

    International Nuclear Information System (INIS)

    Lebrun, A.; Kane, S. C.; Bourva, L.; Poirier, S.; Loghin, N. E.; Langlands, D.

    2009-01-01

    The International Atomic Energy Agency (IAEA) has initiated a coordinated research and development programme to improve its verification methods and equipment applicable to enrichment plants. The programme entails several individual projects to meet the objectives of the IAEA Safeguards Model Approach for Gas Centrifuge Enrichment Plants updated in 2006. Upgrades of verification methods to confirm the absence of HEU (highly enriched uranium) production have been initiated and, in particular, the Cascade Header Enrichment Monitor (CHEM) has been redesigned to reduce its weight and incorporate an electrically cooled germanium detector. Such detectors are also introduced to improve the attended verification of UF 6 cylinders for the verification of the material balance. Data sharing of authenticated operator weighing systems such as accountancy scales and process load cells is also investigated as a cost efficient and an effective safeguards measure combined with unannounced inspections, surveillance and non-destructive assay (NDA) measurement. (authors)

  6. Improved verification methods for safeguards verifications at enrichment plants

    Energy Technology Data Exchange (ETDEWEB)

    Lebrun, A.; Kane, S. C.; Bourva, L.; Poirier, S.; Loghin, N. E.; Langlands, D. [Department of Safeguards, International Atomic Energy Agency, Wagramer Strasse 5, A1400 Vienna (Austria)

    2009-07-01

    The International Atomic Energy Agency (IAEA) has initiated a coordinated research and development programme to improve its verification methods and equipment applicable to enrichment plants. The programme entails several individual projects to meet the objectives of the IAEA Safeguards Model Approach for Gas Centrifuge Enrichment Plants updated in 2006. Upgrades of verification methods to confirm the absence of HEU (highly enriched uranium) production have been initiated and, in particular, the Cascade Header Enrichment Monitor (CHEM) has been redesigned to reduce its weight and incorporate an electrically cooled germanium detector. Such detectors are also introduced to improve the attended verification of UF{sub 6} cylinders for the verification of the material balance. Data sharing of authenticated operator weighing systems such as accountancy scales and process load cells is also investigated as a cost efficient and an effective safeguards measure combined with unannounced inspections, surveillance and non-destructive assay (NDA) measurement. (authors)

  7. Projected Impact of Compositional Verification on Current and Future Aviation Safety Risk

    Science.gov (United States)

    Reveley, Mary S.; Withrow, Colleen A.; Leone, Karen M.; Jones, Sharon M.

    2014-01-01

    The projected impact of compositional verification research conducted by the National Aeronautic and Space Administration System-Wide Safety and Assurance Technologies on aviation safety risk was assessed. Software and compositional verification was described. Traditional verification techniques have two major problems: testing at the prototype stage where error discovery can be quite costly and the inability to test for all potential interactions leaving some errors undetected until used by the end user. Increasingly complex and nondeterministic aviation systems are becoming too large for these tools to check and verify. Compositional verification is a "divide and conquer" solution to addressing increasingly larger and more complex systems. A review of compositional verification research being conducted by academia, industry, and Government agencies is provided. Forty-four aviation safety risks in the Biennial NextGen Safety Issues Survey were identified that could be impacted by compositional verification and grouped into five categories: automation design; system complexity; software, flight control, or equipment failure or malfunction; new technology or operations; and verification and validation. One capability, 1 research action, 5 operational improvements, and 13 enablers within the Federal Aviation Administration Joint Planning and Development Office Integrated Work Plan that could be addressed by compositional verification were identified.

  8. Surface stabilized GMR nanorods of silver coated CrO2 synthesized via a polymer complex at ambient pressure

    Science.gov (United States)

    Biswas, S.; Singh, G. P.; Ram, S.; Fecht, H.-J.

    2013-08-01

    Stable anisotropic nanorods of surface modified CrO2 (˜18 nm diameter) with a correlated diamagnetic layer (2-3 nm thickness) of silver efficiently tailors useful magnetic and magnetoresistance (MR) properties. Essentially, it involves a core-shell structure that is developed by displacing part of Cr4+ ions by Ag atoms on the CrO2 surface (topotactic surface layer) via an etching reaction of a CrO2-polymer complex with Ag+ ions in hot water followed by heating the dried sample at 300-400 °C in air. The stable Ag-layer so obtained in the form of a shell protects CrO2 such that it no longer converts to Cr2O3 in ambient pressure during the processing. X-ray diffractogram of the Rutile type tetragonal CrO2 structure (lattice parameters a=0.4429 nm and c=0.2950 nm) includes weak peaks of a minority phase of an fcc-Ag (a=0.4086 nm). The silver surface layer, which manifests itself in a doublet of the 3d5/2 and 3d3/2 X-ray photoelectron bands of binding energies 368.46 eV and 374.48 eV, respectively, suppresses almost all Cr bands to appear in a measurable intensity. The sample exhibits a distinctly enhanced MR-value, e.g., (-) 7.6% at 77 K, than reported values in compacted CrO2 powders or composites. Such a large MR-value in the Coulomb blockade regime (<100 K) arises not only due to the suppressed spin flipping at low temperature but also from a spin dependent co-tunneling through an interlinked structure of silver and silver coated CrO2 nanorods.

  9. Organics Verification Study for Sinclair and Dyes Inlets, Washington

    Energy Technology Data Exchange (ETDEWEB)

    Kohn, Nancy P.; Brandenberger, Jill M.; Niewolny, Laurie A.; Johnston, Robert K.

    2006-09-28

    Sinclair and Dyes Inlets near Bremerton, Washington, are on the State of Washington 1998 303(d) list of impaired waters because of fecal coliform contamination in marine water, metals in sediment and fish tissue, and organics in sediment and fish tissue. Because significant cleanup and source control activities have been conducted in the inlets since the data supporting the 1998 303(d) listings were collected, two verification studies were performed to address the 303(d) segments that were listed for metal and organic contaminants in marine sediment. The Metals Verification Study (MVS) was conducted in 2003; the final report, Metals Verification Study for Sinclair and Dyes Inlets, Washington, was published in March 2004 (Kohn et al. 2004). This report describes the Organics Verification Study that was conducted in 2005. The study approach was similar to the MVS in that many surface sediment samples were screened for the major classes of organic contaminants, and then the screening results and other available data were used to select a subset of samples for quantitative chemical analysis. Because the MVS was designed to obtain representative data on concentrations of contaminants in surface sediment throughout Sinclair Inlet, Dyes Inlet, Port Orchard Passage, and Rich Passage, aliquots of the 160 MVS sediment samples were used in the analysis for the Organics Verification Study. However, unlike metals screening methods, organics screening methods are not specific to individual organic compounds, and are not available for some target organics. Therefore, only the quantitative analytical results were used in the organics verification evaluation. The results of the Organics Verification Study showed that sediment quality outside of Sinclair Inlet is unlikely to be impaired because of organic contaminants. Similar to the results for metals, in Sinclair Inlet, the distribution of residual organic contaminants is generally limited to nearshore areas already within the

  10. The interaction between surface color and color knowledge: behavioral and electrophysiological evidence.

    Science.gov (United States)

    Bramão, Inês; Faísca, Luís; Forkstam, Christian; Inácio, Filomena; Araújo, Susana; Petersson, Karl Magnus; Reis, Alexandra

    2012-02-01

    In this study, we used event-related potentials (ERPs) to evaluate the contribution of surface color and color knowledge information in object identification. We constructed two color-object verification tasks - a surface and a knowledge verification task - using high color diagnostic objects; both typical and atypical color versions of the same object were presented. Continuous electroencephalogram was recorded from 26 subjects. A cluster randomization procedure was used to explore the differences between typical and atypical color objects in each task. In the color knowledge task, we found two significant clusters that were consistent with the N350 and late positive complex (LPC) effects. Atypical color objects elicited more negative ERPs compared to typical color objects. The color effect found in the N350 time window suggests that surface color is an important cue that facilitates the selection of a stored object representation from long-term memory. Moreover, the observed LPC effect suggests that surface color activates associated semantic knowledge about the object, including color knowledge representations. We did not find any significant differences between typical and atypical color objects in the surface color verification task, which indicates that there is little contribution of color knowledge to resolve the surface color verification. Our main results suggest that surface color is an important visual cue that triggers color knowledge, thereby facilitating object identification. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. Accurate prediction of complex free surface flow around a high speed craft using a single-phase level set method

    Science.gov (United States)

    Broglia, Riccardo; Durante, Danilo

    2017-11-01

    This paper focuses on the analysis of a challenging free surface flow problem involving a surface vessel moving at high speeds, or planing. The investigation is performed using a general purpose high Reynolds free surface solver developed at CNR-INSEAN. The methodology is based on a second order finite volume discretization of the unsteady Reynolds-averaged Navier-Stokes equations (Di Mascio et al. in A second order Godunov—type scheme for naval hydrodynamics, Kluwer Academic/Plenum Publishers, Dordrecht, pp 253-261, 2001; Proceedings of 16th international offshore and polar engineering conference, San Francisco, CA, USA, 2006; J Mar Sci Technol 14:19-29, 2009); air/water interface dynamics is accurately modeled by a non standard level set approach (Di Mascio et al. in Comput Fluids 36(5):868-886, 2007a), known as the single-phase level set method. In this algorithm the governing equations are solved only in the water phase, whereas the numerical domain in the air phase is used for a suitable extension of the fluid dynamic variables. The level set function is used to track the free surface evolution; dynamic boundary conditions are enforced directly on the interface. This approach allows to accurately predict the evolution of the free surface even in the presence of violent breaking waves phenomena, maintaining the interface sharp, without any need to smear out the fluid properties across the two phases. This paper is aimed at the prediction of the complex free-surface flow field generated by a deep-V planing boat at medium and high Froude numbers (from 0.6 up to 1.2). In the present work, the planing hull is treated as a two-degree-of-freedom rigid object. Flow field is characterized by the presence of thin water sheets, several energetic breaking waves and plungings. The computational results include convergence of the trim angle, sinkage and resistance under grid refinement; high-quality experimental data are used for the purposes of validation, allowing to

  12. Verification report for SIMREP 1.1

    International Nuclear Information System (INIS)

    Tarapore, P.S.

    1987-06-01

    SIMREP 1.1 is a discrete event computer simulation of repository operations in the surface waste-handling facility. The logic for this model is provided by Fluor Technology, Inc., the Architect/Engineer of the salt repository. The verification methods included a line-by-line review of the code, a detailed examination of a generated trace of all simulated events over a given period of operations, and a comparison of the simulation output results with expected values. SIMREP 1.1 performs in the required manner under the given range of input conditions

  13. Inner-sphere complexation of cations at the rutile-water interface: A concise surface structural interpretation with the CD and MUSIC model

    NARCIS (Netherlands)

    Ridley, M.K.; Hiemstra, T.; Riemsdijk, van W.H.; Machesky, M.L.

    2009-01-01

    Acid–base reactivity and ion-interaction between mineral surfaces and aqueous solutions is most frequently investigated at the macroscopic scale as a function of pH. Experimental data are then rationalized by a variety of surface complexation models. These models are thermodynamically based which in

  14. Neptunium (V) Adsorption to a Halophilic Bacterium Under High Ionic Strength Conditions: A Surface Complexation Modeling Approach

    Energy Technology Data Exchange (ETDEWEB)

    Ams, David A [Los Alamos National Laboratory

    2012-06-11

    Rationale for experimental design: Np(V) -- important as analog for Pu(V) and for HLW scenarios; High ionic strength -- relevant to salt-based repositories such as the WIPP; Halophilic microorganisms -- representative of high ionic strength environments. For the first time showed: Significant adsorbant to halophilic microorganisms over entire pH range under high ionic strength conditions; Strong influence of ionic strength with increasing adsorption with increasing ionic strength (in contrast to trends of previous low ionic strength studies); Effect of aqueous Np(V) and bacterial surface site speciation on adsorption; and Developed thermodynamic models that can be incorporated into geochemical speciation models to aid in the prediction of the fate and transport of Np(V) in more complex systems.

  15. Surface-enhanced Raman scattering and density functional theory study of 1,4-benzenedithiol and its silver complexes.

    Science.gov (United States)

    Shao, Yangfan; Li, Chongyang; Feng, Yuanming; Lin, Wang

    2013-12-01

    This paper experimentally and theoretically investigated Raman and surface-enhanced Raman scattering (SERS) of 1,4-benzenedithiol (1,4-BDT). Density functional theory methods were used to study Raman scattering spectra of isolated 1,4-BDT and 1,4-BDT-Agn (n=2,4,6) complexes with B3LYP/6-311+g(d)(C,H,S)/Lanl2dz(Ag) basis set. A full assignment of the Raman spectrum of 1,4-BDT has been made based on the DFT analysis. The calculated data showed good agreement with experimental observations. The adsorption sites, metal cluster size, and HOMO-LUMO energies are discussed to give insight in the SERS mechanisms for 1,4-BDT molecules. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Role of competing ions in the mobilization of arsenic in groundwater of Bengal Basin: insight from surface complexation modeling.

    Science.gov (United States)

    Biswas, Ashis; Gustafsson, Jon Petter; Neidhardt, Harald; Halder, Dipti; Kundu, Amit K; Chatterjee, Debashis; Berner, Zsolt; Bhattacharya, Prosun

    2014-05-15

    This study assesses the role of competing ions in the mobilization of arsenic (As) by surface complexation modeling of the temporal variability of As in groundwater. The potential use of two different surface complexation models (SCMs), developed for ferrihydrite and goethite, has been explored to account for the temporal variation of As(III) and As(V) concentration, monitored in shallow groundwater of Bengal Basin over a period of 20 months. The SCM for ferrihydrite appears as the better predictor of the observed variation in both As(III) and As(V) concentrations in the study sites. It is estimated that among the competing ions, PO4(3-) is the major competitor of As(III) and As(V) adsorption onto Fe oxyhydroxide, and the competition ability decreases in the order PO4(3-) ≫ Fe(II) > H4SiO4 = HCO3(-). It is further revealed that a small change in pH can also have a significant effect on the mobility of As(III) and As(V) in the aquifers. A decrease in pH increases the concentration of As(III), whereas it decreases the As(V) concentration and vice versa. The present study suggests that the reductive dissolution of Fe oxyhydroxide alone cannot explain the observed high As concentration in groundwater of the Bengal Basin. This study supports the view that the reductive dissolution of Fe oxyhydroxide followed by competitive sorption reactions with the aquifer sediment is the processes responsible for As enrichment in groundwater. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Numident Online Verification Utility (NOVU)

    Data.gov (United States)

    Social Security Administration — NOVU is a mainframe application that accesses the NUMIDENT to perform real-time SSN verifications. This program is called by other SSA online programs that serve as...

  18. Theoretical investigation of potential energy surface and bound states for the van der Waals complex Ar–BrCl dimer

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Rui [School of Mathematics and Information Science, North China University of Water Resources and Electric Power, Zhengzhou (China); Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Centre for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan (China); Li, Song, E-mail: lsong@yangtzeu.edu.cn [School of Physics and Optoelectronic Engineering, Yangtze University, Jingzhou (China); Chen, Shan-Jun; Chen, Yan [School of Physics and Optoelectronic Engineering, Yangtze University, Jingzhou (China); Zheng, Li-Min [Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Centre for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan (China)

    2015-09-08

    Highlights: • A two-dimensional potential for Ar–BrCl is constructed at the CCSD(T) level. • The PES is characterized by three minima and two saddle points between them. • Bound state calculations were carried out for the complex. - Abstract: The intermolecular potential energy surface (PES) of the ground electronic state for the Ar–BrCl dimer is constructed at the CCSD(T) level with the aug-cc-pVQZ basis set and mid-bond functions. The PES is characterized by three minima and two saddle points. The global minimum corresponding to a collinear Ar–BrCl configuration, which has been observed experimentally, is located at R = 4.10 Å and θ = 2.5° with a well depth of −285.207 cm{sup −1}. A nearly T-shaped structure and an anti-linear Ar–ClBr geometry is also predicted. The bound state calculations are preformed to study intermolecular vibrational modes, rotational levels and average structures for the complex. Our transition frequencies, spectroscopic constants and average structures for all isotopomers of the collinear isomer agree well with experimental data. We have also provided pure rotational transitional frequencies for both nearly T-shaped and anti-linear isomers. These results are significant for further experimental investigations of the Ar–BrCl dimer.

  19. Potential energy surface of the CO{sub 2}–N{sub 2} van der Waals complex

    Energy Technology Data Exchange (ETDEWEB)

    Nasri, Sameh; Ajili, Yosra [Laboratoire de Spectroscopie Atomique, Moléculaire et Applications-LSAMA, Université de Tunis El Manar, Tunis (Tunisia); Université Paris-Est, Laboratoire Modélisation et Simulation Multi Echelle, MSME UMR 8208 CNRS, 5 bd Descartes, 77454 Marne-la-Vallée (France); Jaidane, Nejm-Eddine [Laboratoire de Spectroscopie Atomique, Moléculaire et Applications-LSAMA, Université de Tunis El Manar, Tunis (Tunisia); Kalugina, Yulia N. [Department of Optics and Spectroscopy, Tomsk State University, 36 Lenin Ave., Tomsk 634050 (Russian Federation); Halvick, Philippe; Stoecklin, Thierry [Institut des Sciences Moléculaires, Université de Bordeaux, CNRS UMR 5255, 33405 Talence Cedex (France); Hochlaf, Majdi, E-mail: hochlaf@univ-mlv.fr [Université Paris-Est, Laboratoire Modélisation et Simulation Multi Echelle, MSME UMR 8208 CNRS, 5 bd Descartes, 77454 Marne-la-Vallée (France)

    2015-05-07

    Four-dimensional potential energy surface (4D-PES) of the atmospherically relevant CO{sub 2}–N{sub 2} van der Waals complex is generated using the explicitly correlated coupled cluster with single, double, and perturbative triple excitation (CCSD(T)-F12) method in conjunction with the augmented correlation consistent triple zeta (aug-cc-pVTZ) basis set. This 4D-PES is mapped along the intermonomer coordinates. An analytic fit of this 4D-PES is performed. Our extensive computations confirm that the most stable form corresponds to a T-shape structure where the nitrogen molecule points towards the carbon atom of CO{sub 2}. In addition, we located a second isomer and two transition states in the ground state PES of CO{sub 2}–N{sub 2}. All of them lay below the CO{sub 2} + N{sub 2} dissociation limit. This 4D-PES is flat and strongly anisotropic along the intermonomer coordinates. This results in the possibility of the occurrence of large amplitude motions within the complex, such as the inversion of N{sub 2}, as suggested in the recent spectroscopic experiments. Finally, we show that the experimentally established deviations from the C{sub 2v} structure at equilibrium for the most stable isomer are due to the zero-point out-of-plane vibration correction.

  20. Structure and reactivity of oxalate surface complexes on lepidocrocite derived from infrared spectroscopy, DFT-calculations, adsorption, dissolution and photochemical experiments

    Science.gov (United States)

    Borowski, Susan C.; Biswakarma, Jagannath; Kang, Kyounglim; Schenkeveld, Walter D. C.; Hering, Janet G.; Kubicki, James D.; Kraemer, Stephan M.; Hug, Stephan J.

    2018-04-01

    Oxalate, together with other ligands, plays an important role in the dissolution of iron(hdyr)oxides and the bio-availability of iron. The formation and properties of oxalate surface complexes on lepidocrocite were studied with a combination of infrared spectroscopy (IR), density functional theory (DFT) calculations, dissolution, and photochemical experiments. IR spectra measured as a function of time, concentration, and pH (50-200 μM oxalate, pH 3-7) showed that several surface complexes are formed at different rates and in different proportions. Measured spectra could be separated into three contributions described by Gaussian line shapes, with frequencies that agreed well with the theoretical frequencies of three different surface complexes: an outer-sphere complex (OS), an inner-sphere monodentate mononuclear complex (MM), and a bidentate mononuclear complex (BM) involving one O atom from each carboxylate group. At pH 6, OS was formed at the highest rate. The contribution of BM increased with decreasing pH. In dissolution experiments, lepidocrocite was dissolved at rates proportional to the surface concentration of BM, rather than to the total adsorbed concentration. Under UV-light (365 nm), BM was photolyzed at a higher rate than MM and OS. Although the comparison of measured spectra with calculated frequencies cannot exclude additional possible structures, the combined results allowed the assignment of three main structures with different reactivities consistent with experiments. The results illustrate the importance of the surface speciation of adsorbed ligands in dissolution and photochemical reactions.

  1. Tomotherapy: IMRT and tomographic verification

    International Nuclear Information System (INIS)

    Mackie, T.R.

    2000-01-01

    include MLC's and many clinics use them to replace 90% or more of the field-shaping requirements of conventional radiotherapy. Now, several academic centers are treating patients with IMRT using conventional MLC's to modulate the field. IMRT using conventional MLC's have the advantage that the patient is stationary during the treatment and the MLC's can be used in conventional practice. Nevertheless, tomotherapy using the Peacock system delivers the most conformal dose distributions of any commercial system to date. The biggest limitation with the both the NOMOS Peacock tomotherapy system and conventional MLC's for IMRT delivery is the lack of treatment verification. In conventional few-field radiotherapy one relied on portal images to determine if the patient was setup correctly and the beams were correctly positioned. With IMRT the image contrast is superimposed on the beam intensity variation. Conventional practice allowed for monitor unit calculation checks and point dosimeters placed on the patient's surface to verify that the treatment was properly delivered. With IMRT it is impossible to perform hand calculations of monitor units and dosimeters placed on the patient's surface are prone to error due to high gradients in the beam intensity. NOMOS has developed a verification phantom that allows multiple sheets of film to be placed in a light-tight box that is irradiated with the same beam pattern that is used to treat the patient. The optical density of the films are adjusted, normalized, and calibrated and then quantitatively compared with the dose calculated for the phantom delivery. However, this process is too laborious to be used for patient-specific QA. If IMRT becomes ubiquitous and it can be shown that IMRT is useful on most treatment sites then there is a need to design treatment units dedicated to IMRT delivery and verification. Helical tomotherapy is such a redesign. Helical tomotherapy is the delivery of a rotational fan beam while the patient is

  2. Cleanup Verification Package for the 600-47 Waste Site

    International Nuclear Information System (INIS)

    Cutlip, M.J.

    2005-01-01

    This cleanup verification package documents completion of interim remedial action for the 600-47 waste site. This site consisted of several areas of surface debris and contamination near the banks of the Columbia River across from Johnson Island. Contaminated material identified in field surveys included four areas of soil, wood, nuts, bolts, and other metal debris

  3. SiSn diodes: Theoretical analysis and experimental verification

    KAUST Repository

    Hussain, Aftab M.; Wehbe, Nimer; Hussain, Muhammad Mustafa

    2015-01-01

    We report a theoretical analysis and experimental verification of change in band gap of silicon lattice due to the incorporation of tin (Sn). We formed SiSn ultra-thin film on the top surface of a 4 in. silicon wafer using thermal diffusion of Sn

  4. Three-channel false colour AFM images for improved interpretation of complex surfaces: A study of filamentous cyanobacteria

    International Nuclear Information System (INIS)

    Kurk, Toby; Adams, David G.; Connell, Simon D.; Thomson, Neil H.

    2010-01-01

    Imaging signals derived from the atomic force microscope (AFM) are typically presented as separate adjacent images with greyscale or pseudo-colour palettes. We propose that information-rich false-colour composites are a useful means of presenting three-channel AFM image data. This method can aid the interpretation of complex surfaces and facilitate the perception of information that is convoluted across data channels. We illustrate this approach with images of filamentous cyanobacteria imaged in air and under aqueous buffer, using both deflection-modulation (contact) mode and amplitude-modulation (tapping) mode. Topography-dependent contrast in the error and tertiary signals aids the interpretation of the topography signal by contributing additional data, resulting in a more detailed image, and by showing variations in the probe-surface interaction. Moreover, topography-independent contrast and topography-dependent contrast in the tertiary data image (phase or friction) can be distinguished more easily as a consequence of the three dimensional colour-space.

  5. Long-term drug modification to the surface of mesenchymal stem cells by the avidin-biotin complex method.

    Science.gov (United States)

    Takayama, Yukiya; Kusamori, Kosuke; Hayashi, Mika; Tanabe, Noriko; Matsuura, Satoru; Tsujimura, Mari; Katsumi, Hidemasa; Sakane, Toshiyasu; Nishikawa, Makiya; Yamamoto, Akira

    2017-12-05

    Mesenchymal stem cells (MSCs) have various functions, making a significant contribution to tissue repair. On the other hand, the viability and function of MSCs are not lasting after an in vivo transplant, and the therapeutic effects of MSCs are limited. Although various chemical modification methods have been applied to MSCs to improve their viability and function, most of conventional drug modification methods are short-term and unstable and cause cytotoxicity. In this study, we developed a method for long-term drug modification to C3H10T1/2 cells, murine mesenchymal stem cells, without any damage, using the avidin-biotin complex method (ABC method). The modification of NanoLuc luciferase (Nluc), a reporter protein, to C3H10T1/2 cells by the ABC method lasted for at least 14 days in vitro without major effects on the cellular characteristics (cell viability, cell proliferation, migration ability, and differentiation ability). Moreover, in vivo, the surface Nluc modification to C3H10T1/2 cells by the ABC method lasted for at least 7 days. Therefore, these results indicate that the ABC method may be useful for long-term surface modification of drugs and for effective MSC-based therapy.

  6. Synthesis, structural characterization, Hirshfeld surface analysis and spectroscopic studies of cadmium (II) chloride complex with 4-hydroxy-1-methylpiperidine

    Energy Technology Data Exchange (ETDEWEB)

    Soudani, S. [Université de Carthage, Laboratoire de Chimie des Matériaux, Faculté des Sciences de Bizerte, 7021 Zarzouna (Tunisia); Ferretti, V. [Department of Chemical and Pharmaceutical Sciences and Center for Structural Diffractometry, via Fossato di Mortara 17, I-44121 Ferrara (Italy); Jelsch, C. [CRM2, CNRS, Institut Jean Barriol, Université de Lorraine, Vandoeuvre les Nancy CEDEX (France); Lefebvre, F. [Laboratoire de Chimie Organométallique de Surface (LCOMS), Ecole Supérieure de Chimie Physique Electronique, 69626 Villeurbanne Cedex (France); Nasr, C. Ben, E-mail: cherif_bennasr@yahoo.fr [Université de Carthage, Laboratoire de Chimie des Matériaux, Faculté des Sciences de Bizerte, 7021 Zarzouna (Tunisia)

    2016-05-15

    The chemical preparation, crystal structure, Hirshfeld surface analysis and spectroscopic characterization of the novel cadmium (II) 4-hydroxy-1-methylpiperidine complex, Cd{sub 4}Cl{sub 10}(C{sub 6}H{sub 14}NO){sub 2}·2H{sub 2}O, have been reported. The atomic arrangement can be described as built up by an anionic framework, formed by edge sharing CdCl{sub 6} and CdCl{sub 5}O octahedral linear chains spreading along the a-axis. These chains are interconnected by water molecules via O–H⋯Cl and O–H⋯O hydrogen bonds to form layers parallel to (011) plane. The organic cations are inserted between layers through C–H⋯Cl hydrogen bonds. Investigation of intermolecular interactions and crystal packing via Hirshfeld surface analysis reveals that the H{sub C}⋯Cl and H{sub C}⋯H{sub C} intermolecular interactions are the most abundant contacts of the organic cation in the crystal packing. The statistical analysis of crystal contacts reveals the driving forces in the packing formation. The {sup 13}C and {sup 15}N CP-MAS NMR spectra are in agreement with the X-ray structure. The vibrational absorption bands were identified by infrared spectroscopy. DFT calculations allowed the attribution of the NMR peaks and of the IR bands.

  7. Three-channel false colour AFM images for improved interpretation of complex surfaces: A study of filamentous cyanobacteria

    Energy Technology Data Exchange (ETDEWEB)

    Kurk, Toby, E-mail: phytak@leeds.ac.uk [School of Physics and Astronomy, University of Leeds, Leeds, West Yorkshire LS2 9JT (United Kingdom); Adams, David G., E-mail: D.G.Adams@leeds.ac.uk [Faculty of Biological Sciences, University of Leeds, Leeds, West Yorkshire LS2 9JT (United Kingdom); Connell, Simon D., E-mail: S.D.A.Connell@leeds.ac.uk [School of Physics and Astronomy, University of Leeds, Leeds, West Yorkshire LS2 9JT (United Kingdom); Thomson, Neil H., E-mail: N.H.Thomson@leeds.ac.uk [School of Physics and Astronomy, University of Leeds, Leeds, West Yorkshire LS2 9JT (United Kingdom); Dental Institute, University of Leeds, Leeds, West Yorkshire LS2 9JT (United Kingdom)

    2010-05-15

    Imaging signals derived from the atomic force microscope (AFM) are typically presented as separate adjacent images with greyscale or pseudo-colour palettes. We propose that information-rich false-colour composites are a useful means of presenting three-channel AFM image data. This method can aid the interpretation of complex surfaces and facilitate the perception of information that is convoluted across data channels. We illustrate this approach with images of filamentous cyanobacteria imaged in air and under aqueous buffer, using both deflection-modulation (contact) mode and amplitude-modulation (tapping) mode. Topography-dependent contrast in the error and tertiary signals aids the interpretation of the topography signal by contributing additional data, resulting in a more detailed image, and by showing variations in the probe-surface interaction. Moreover, topography-independent contrast and topography-dependent contrast in the tertiary data image (phase or friction) can be distinguished more easily as a consequence of the three dimensional colour-space.

  8. Surface stabilized GMR nanorods of silver coated CrO{sub 2} synthesized via a polymer complex at ambient pressure

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, S., E-mail: drsomnathbiswas@gmail.com [The LNM Institute of Information Technology, Jaipur-302031 (India); Singh, G.P. [Centre for Nanotechnology, Central University of Jharkhand, Ranchi-835205 (India); Ram, S. [Materials Science Centre, Indian Institute of Technology, Kharagpur-721302 (India); Fecht, H.-J. [Insitut für Micro-und Nanomaterialien, Universität Ulm, Albert Einstein Allee-47, Ulm, D-89081, and Forschungszentrum Karlsruhe, Institute of Nanotechnology, Karlsruhe, D-76021 (Germany)

    2013-08-15

    Stable anisotropic nanorods of surface modified CrO{sub 2} (∼18 nm diameter) with a correlated diamagnetic layer (2–3 nm thickness) of silver efficiently tailors useful magnetic and magnetoresistance (MR) properties. Essentially, it involves a core-shell structure that is developed by displacing part of Cr{sup 4+} ions by Ag atoms on the CrO{sub 2} surface (topotactic surface layer) via an etching reaction of a CrO{sub 2}-polymer complex with Ag{sup +} ions in hot water followed by heating the dried sample at 300–400 °C in air. The stable Ag-layer so obtained in the form of a shell protects CrO{sub 2} such that it no longer converts to Cr{sub 2}O{sub 3} in ambient pressure during the processing. X-ray diffractogram of the Rutile type tetragonal CrO{sub 2} structure (lattice parameters a=0.4429 nm and c=0.2950 nm) includes weak peaks of a minority phase of an fcc-Ag (a=0.4086 nm). The silver surface layer, which manifests itself in a doublet of the 3d{sub 5/2} and 3d{sub 3/2} X-ray photoelectron bands of binding energies 368.46 eV and 374.48 eV, respectively, suppresses almost all Cr bands to appear in a measurable intensity. The sample exhibits a distinctly enhanced MR-value, e.g., (−) 7.6% at 77 K, than reported values in compacted CrO{sub 2} powders or composites. Such a large MR-value in the Coulomb blockade regime (<100 K) arises not only due to the suppressed spin flipping at low temperature but also from a spin dependent co-tunneling through an interlinked structure of silver and silver coated CrO{sub 2} nanorods. - Highlights: • Synthesis and structural studies of a novel GMR material of Ag coated CrO{sub 2}. • Tailoring useful GMR property in CrO{sub 2} nanorods of controlled shape and anisotropy. • Enhanced GMR is explained in correlation to the surface structure of CrO{sub 2} nanorods.

  9. Technical safety requirements control level verification

    International Nuclear Information System (INIS)

    STEWART, J.L.

    1999-01-01

    A Technical Safety Requirement (TSR) control level verification process was developed for the Tank Waste Remediation System (TWRS) TSRs at the Hanford Site in Richland, WA, at the direction of the US. Department of Energy, Richland Operations Office (RL). The objective of the effort was to develop a process to ensure that the TWRS TSR controls are designated and managed at the appropriate levels as Safety Limits (SLs), Limiting Control Settings (LCSs), Limiting Conditions for Operation (LCOs), Administrative Controls (ACs), or Design Features. The TSR control level verification process was developed and implemented by a team of contractor personnel with the participation of Fluor Daniel Hanford, Inc. (FDH), the Project Hanford Management Contract (PHMC) integrating contractor, and RL representatives. The team was composed of individuals with the following experience base: nuclear safety analysis; licensing; nuclear industry and DOE-complex TSR preparation/review experience; tank farm operations; FDH policy and compliance; and RL-TWRS oversight. Each TSR control level designation was completed utilizing TSR control logic diagrams and TSR criteria checklists based on DOE Orders, Standards, Contractor TSR policy, and other guidance. The control logic diagrams and criteria checklists were reviewed and modified by team members during team meetings. The TSR control level verification process was used to systematically evaluate 12 LCOs, 22 AC programs, and approximately 100 program key elements identified in the TWRS TSR document. The verification of each TSR control required a team consensus. Based on the results of the process, refinements were identified and the TWRS TSRs were modified as appropriate. A final report documenting key assumptions and the control level designation for each TSR control was prepared and is maintained on file for future reference. The results of the process were used as a reference in the RL review of the final TWRS TSRs and control suite. RL

  10. Technical safety requirements control level verification; TOPICAL

    International Nuclear Information System (INIS)

    STEWART, J.L.

    1999-01-01

    A Technical Safety Requirement (TSR) control level verification process was developed for the Tank Waste Remediation System (TWRS) TSRs at the Hanford Site in Richland, WA, at the direction of the US. Department of Energy, Richland Operations Office (RL). The objective of the effort was to develop a process to ensure that the TWRS TSR controls are designated and managed at the appropriate levels as Safety Limits (SLs), Limiting Control Settings (LCSs), Limiting Conditions for Operation (LCOs), Administrative Controls (ACs), or Design Features. The TSR control level verification process was developed and implemented by a team of contractor personnel with the participation of Fluor Daniel Hanford, Inc. (FDH), the Project Hanford Management Contract (PHMC) integrating contractor, and RL representatives. The team was composed of individuals with the following experience base: nuclear safety analysis; licensing; nuclear industry and DOE-complex TSR preparation/review experience; tank farm operations; FDH policy and compliance; and RL-TWRS oversight. Each TSR control level designation was completed utilizing TSR control logic diagrams and TSR criteria checklists based on DOE Orders, Standards, Contractor TSR policy, and other guidance. The control logic diagrams and criteria checklists were reviewed and modified by team members during team meetings. The TSR control level verification process was used to systematically evaluate 12 LCOs, 22 AC programs, and approximately 100 program key elements identified in the TWRS TSR document. The verification of each TSR control required a team consensus. Based on the results of the process, refinements were identified and the TWRS TSRs were modified as appropriate. A final report documenting key assumptions and the control level designation for each TSR control was prepared and is maintained on file for future reference. The results of the process were used as a reference in the RL review of the final TWRS TSRs and control suite. RL

  11. Inventory of present verification techniques. Viewpoint of EURATOM

    International Nuclear Information System (INIS)

    Kloeckner, W.; Eecken, D. Van der; Gmelin, W.

    1998-01-01

    Starting from the role of Euratom as an established regional safeguards system, an overview is given of verification techniques currently practised by Euratom. In the stage-light of a rapidly changing and complex international safeguards scene, Euratom considers it has an important role to play. Having in mind the possibilities created by accelerating modern technology, recommendations are given for an enhanced use of technological means in safeguards. The viewpoint of Euratom is that the majority of methodologies and techniques in place may very well be copied to or used for a cut-off verification system currently under discussion

  12. Verification and Validation for Flight-Critical Systems (VVFCS)

    Science.gov (United States)

    Graves, Sharon S.; Jacobsen, Robert A.

    2010-01-01

    On March 31, 2009 a Request for Information (RFI) was issued by NASA s Aviation Safety Program to gather input on the subject of Verification and Validation (V & V) of Flight-Critical Systems. The responses were provided to NASA on or before April 24, 2009. The RFI asked for comments in three topic areas: Modeling and Validation of New Concepts for Vehicles and Operations; Verification of Complex Integrated and Distributed Systems; and Software Safety Assurance. There were a total of 34 responses to the RFI, representing a cross-section of academic (26%), small & large industry (47%) and government agency (27%).

  13. IDEF method for designing seismic information system in CTBT verification

    International Nuclear Information System (INIS)

    Zheng Xuefeng; Shen Junyi; Jin Ping; Zhang Huimin; Zheng Jiangling; Sun Peng

    2004-01-01

    Seismic information system is of great importance for improving the capability of CTBT verification. A large amount of money has been appropriated for the research in this field in the U.S. and some other countries in recent years. However, designing and developing a seismic information system involves various technologies about complex system design. This paper discusses the IDEF0 method to construct function models and the IDEF1x method to make information models systemically, as well as how they are used in designing seismic information system in CTBT verification. (authors)

  14. Modeling the adsorption of metal ions (Cu 2+, Ni 2+, Pb 2+) onto ACCs using surface complexation models

    Science.gov (United States)

    Faur-Brasquet, Catherine; Reddad, Zacaria; Kadirvelu, Krishna; Le Cloirec, Pierre

    2002-08-01

    Activated carbon cloths (ACCs), whose efficiency has been demonstrated for microorganics adsorption from water, were here studied in the removal of metal ions from aqueous solution. Two ACCs are investigated, they are characterized in terms of porosity parameters (BET specific surface area, percentage of microporosity) and chemical characteristics (acidic surface groups, acidity constants, point of zero charge). A first part consists in the experimental study of three metal ions removal (Cu 2+, Ni 2+ and Pb 2+) in a batch reactor. Isotherms modeling by Freundlich and Brunauer-Emmett-Teller (BET) equations enables the following adsorption order: Cu 2+>Ni 2+>Pb 2+ to be determined for adsorption capacities on a molar basis. It may be related to adsorbates characteristics in terms of electronegativity and ionic radius. The influence of adsorbent's microporosity is also shown. Adsorption experiments carried out for pH values ranging from 2 to 10 demonstrate: (i) an adsorption occurring below the precipitation pH; (ii) the strong influence of pH, with a decrease of electrostatic repulsion due to the formation of less charged hydrolyzed species coupled with a decrease of activated carbon surface charge as pH increases. The second part focuses on the modeling of adsorption versus the pH experimental data by the diffuse layer model (DLM) using Fiteql software. The model is efficient to describe the system behavior in the pH range considered. Regarding complexation constants, they show the following affinity for ACC: Pb 2+>Cu 2+>Ni 2+. They are related to initial concentrations used for the three metal ions.

  15. Uranium(VI) sorption on iron oxides in Hanford Site sediment: Application of a surface complexation model

    International Nuclear Information System (INIS)

    Um, Wooyong; Serne, R. Jeffrey; Brown, Christopher F.; Rod, Kenton A.

    2008-01-01

    Sorption of U(VI) on Hanford fine sand (HFS) with varying Fe-oxide (especially ferrihydrite) contents showed that U(VI) sorption increased with the incremental addition of synthetic ferrihydrite into HFS, consistent with ferrihydrite being one of the most reactive U(VI) sorbents present in natural sediments. Surface complexation model (SCM) calculations for U(VI) sorption, using only U(VI) surface-reaction constants obtained from U(VI) sorption data on freshly synthesized ferrihydrite at different pHs, were similar to the measured U(VI) sorption results on pure synthetic ferrihydrite and on HFS with high contents of ferrihydrite (5 wt%) added. However, the SCM prediction using only U(VI) sorption reactions and constants for synthetic ferrihydrite overestimated U(VI) sorption on the natural HFS or HFS with addition of low amounts of added ferrihydrite (1 wt% added). Over-predicted U(VI) sorption was attributed to reduced reactivity of natural ferrihydrite present in Hanford Site sediments, compared to freshly prepared synthetic ferrihydrite. Even though the SCM general composite (GC) approach is considered to be a semi-quantitative estimation technique for contaminant sorption, which requires systematic experimental data on the sorbent-sorbate system being studied to obtain credible SCM parameters, the general composite SCM model was still found to be a useful technique for describing U(VI) sorption on natural sediments. Based on U(VI) batch sorption results, two simple U(VI) monodentate surface species, SO U O 2 HCO 3 and SO U O 2 OH on ferrihydrite and phyllosillicate in HFS, respectively, can be successfully used to describe U(VI) sorption onto Hanford Site sediment contacting varying geochemical solutions

  16. Effect of pullulan nanoparticle surface charges on HSA complexation and drug release behavior of HSA-bound nanoparticles.

    Directory of Open Access Journals (Sweden)

    Xiaojun Tao

    Full Text Available Nanoparticle (NP compositions such as hydrophobicity and surface charge are vital to determine the presence and amount of human serum albumin (HSA binding. The HSA binding influences drug release, biocompatibility, biodistribution, and intercellular trafficking of nanoparticles (NPs. Here, we prepared 2 kinds of nanomaterials to investigate HSA binding and evaluated drug release of HSA-bound NPs. Polysaccharides (pullulan carboxyethylated to provide ionic derivatives were then conjugated to cholesterol groups to obtain cholesterol-modified carboxyethyl pullulan (CHCP. Cholesterol-modified pullulan (CHP conjugate was synthesized with a similar degree of substitution of cholesterol moiety to CHCP. CHCP formed self-aggregated NPs in aqueous solution with a spherical structure and zeta potential of -19.9 ± 0.23 mV, in contrast to -1.21 ± 0.12 mV of CHP NPs. NPs could quench albumin fluorescence intensity with maximum emission intensity gradually decreasing up to a plateau at 9 to 12 h. Binding constants were 1.12 × 10(5 M(-1 and 0.70 × 10(5 M(-1 to CHP and CHCP, respectively, as determined by Stern-Volmer analysis. The complexation between HSA and NPs was a gradual process driven by hydrophobic force and inhibited by NP surface charge and shell-core structure. HSA conformation was altered by NPs with reduction of α-helical content, depending on interaction time and particle surface charges. These NPs could represent a sustained release carrier for mitoxantrone in vitro, and the bound HSA assisted in enhancing sustained drug release.

  17. Non-invasive identification of metal-oxalate complexes on polychrome artwork surfaces by reflection mid-infrared spectroscopy.

    Science.gov (United States)

    Monico, Letizia; Rosi, Francesca; Miliani, Costanza; Daveri, Alessia; Brunetti, Brunetto G

    2013-12-01

    In this work a reflection mid-infrared spectroscopy study of twelve metal-oxalate complexes, of interest in art conservation science as alteration compounds, was performed. Spectra of the reference materials highlighted the presence of derivative-like and/or inverted features for the fundamental vibrational modes as result of the main contribution from the surface component of the reflected light. In order to provide insights in the interpretation of theses spectral distortions, reflection spectra were compared with conventional transmission ones. The Kramers-Kronig (KK) algorithm, employed to correct for the surface reflection distortions, worked properly only for the derivative-like bands. Therefore, to pay attention to the use of this algorithm when interpreting the reflection spectra is recommended. The outcome of this investigation was exploited to discriminate among different oxalates on thirteen polychrome artworks analyzed in situ by reflection mid-infrared spectroscopy. The visualization of the νs(CO) modes (1400-1200 cm(-1)) and low wavenumber bands (below 900 cm(-1)) in the raw reflection profiles allowed Ca, Cu and Zn oxalates to be identified. Further information about the speciation of different hydration forms of calcium oxalates were obtained by using the KK transform. The work proves reflection mid-infrared spectroscopy to be a reliable and sensitive spectro-analytical method for identifying and mapping different metal-oxalate alteration compounds on the surface of artworks, thus providing conservation scientists with a non-invasive tool to obtain information on the state of conservation and causes of alteration of artworks. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Response surface method applied to the thermoeconomic optimization of a complex cogeneration system modeled in a process simulator

    International Nuclear Information System (INIS)

    Pires, Thiago S.; Cruz, Manuel E.; Colaço, Marcelo J.

    2013-01-01

    This work presents the application of a surrogate model – a response surface – to replace the objective function to be minimized in the thermoeconomic optimization of a complex thermal system modeled with the aid of an expert process simulator. The objective function accounts for fuel, capital, operation and maintenance costs of the thermal system, and depends on nine decision variables. The minimization task is performed through the computational integration of two professional programs, a process simulator and a mathematical platform. Five algorithms are used to perform the optimization: the pattern search and genetic algorithms, both available in the mathematical platform, plus three custom-coded algorithms, differential evolution, particle swarm and simulated annealing. A comparative analysis of the performance of all five methods is presented, together with a critical appraisal of the surrogate model effectiveness. In the course of the optimization procedure, the process simulator computes the thermodynamic properties of all flows of the thermal system and solves the mass and energy balances each time the objective function has to be evaluated. By handling a set of radial basis functions as an approximation model to the original computationally expensive objective function, it is found here that the number of function evaluations can be appreciably reduced without significant deviation of the optimal value. The present study indicates that, for a thermoeconomic system optimization problem with a large number of decision variables and/or a costly objective function, the application of the response surface surrogate may prove more efficient than the original simulation model, reducing substantially the computational time involved in the optimization. - Highlights: ► A successful response surface method was proposed. ► The surrogate model may be more efficient than the original simulation model. ► Relative differences of less than 5% were found for the

  19. Implementation and Testing of Advanced Surface Boundary Conditions Over Complex Terrain in A Semi-idealized Model

    Science.gov (United States)

    Li, Y.; Epifanio, C.

    2017-12-01

    In numerical prediction models, the interaction between the Earth's surface and the atmosphere is typically accounted for in terms of surface layer parameterizations, whose main job is to specify turbulent fluxes of heat, moisture and momentum across the lower boundary of the model domain. In the case of a domain with complex geometry, implementing the flux conditions (particularly the tensor stress condition) at the boundary can be somewhat subtle, and there has been a notable history of confusion in the CFD community over how to formulate and impose such conditions generally. In the atmospheric case, modelers have largely been able to avoid these complications, at least until recently, by assuming that the terrain resolved at typical model resolutions is fairly gentle, in the sense of having relatively shallow slopes. This in turn allows the flux conditions to be imposed as if the lower boundary were essentially flat. Unfortunately, while this flat-boundary assumption is acceptable for coarse resolutions, as grids become more refined and the geometry of the resolved terrain becomes more complex, the appproach is less justified. With this in mind, the goal of our present study is to explore the implementation and usage of the full, unapproximated version of the turbulent flux/stress conditions in atmospheric models, thus taking full account of the complex geometry of the resolved terrain. We propose to implement the conditions using a semi-idealized model developed by Epifanio (2007), in which the discretized boundary conditions are reduced to a large, sparse-matrix problem. The emphasis will be on fluxes of momentum, as the tensor nature of this flux makes the associated stress condition more difficult to impose, although the flux conditions for heat and moisture will be considered as well. With the resulotion of 90 meters, some of the results show that the typical differences between flat-boundary cases and full/stress cases are on the order of 10%, with extreme

  20. Woodward Effect Experimental Verifications

    Science.gov (United States)

    March, Paul

    2004-02-01

    The work of J. F. Woodward (1990 1996a; 1996b; 1998; 2002a; 2002b; 2004) on the existence of ``mass fluctuations'' and their use in exotic propulsion schemes was examined for possible application in improving space flight propulsion and power generation. Woodward examined Einstein's General Relativity Theory (GRT) and assumed that if the strong Machian interpretation of GRT as well as gravitational / inertia like Wheeler-Feynman radiation reaction forces hold, then when an elementary particle is accelerated through a potential gradient, its rest mass should fluctuate around its mean value during its acceleration. Woodward also used GRT to clarify the precise experimental conditions necessary for observing and exploiting these mass fluctuations or ``Woodward effect'' (W-E). Later, in collaboration with his ex-graduate student T. Mahood, they also pushed the experimental verification boundaries of these proposals. If these purported mass fluctuations occur as Woodward claims, and his assumption that gravity and inertia are both byproducts of the same GRT based phenomenon per Mach's Principle is correct, then many innovative applications such as propellantless propulsion and gravitational exotic matter generators may be feasible. This paper examines the reality of mass fluctuations and the feasibility of using the W-E to design propellantless propulsion devices in the near to mid-term future. The latest experimental results, utilizing MHD-like force rectification systems, will also be presented.

  1. Verification of hypergraph states

    Science.gov (United States)

    Morimae, Tomoyuki; Takeuchi, Yuki; Hayashi, Masahito

    2017-12-01

    Hypergraph states are generalizations of graph states where controlled-Z gates on edges are replaced with generalized controlled-Z gates on hyperedges. Hypergraph states have several advantages over graph states. For example, certain hypergraph states, such as the Union Jack states, are universal resource states for measurement-based quantum computing with only Pauli measurements, while graph state measurement-based quantum computing needs non-Clifford basis measurements. Furthermore, it is impossible to classically efficiently sample measurement results on hypergraph states unless the polynomial hierarchy collapses to the third level. Although several protocols have been proposed to verify graph states with only sequential single-qubit Pauli measurements, there was no verification method for hypergraph states. In this paper, we propose a method for verifying a certain class of hypergraph states with only sequential single-qubit Pauli measurements. Importantly, no i.i.d. property of samples is assumed in our protocol: any artificial entanglement among samples cannot fool the verifier. As applications of our protocol, we consider verified blind quantum computing with hypergraph states, and quantum computational supremacy demonstrations with hypergraph states.

  2. Study of solid/liquid and solid/gas interfaces in Cu–isoleucine complex by surface X-ray diffraction

    International Nuclear Information System (INIS)

    Ferrer, Pilar; Rubio-Zuazo, Juan; Castro, German R.

    2013-01-01

    The enzymes could be understood like structures formed by amino acids bonded with metals, which act as active sites. The research on the coordination of metal–amino acid complexes will bring light on the behavior of metal enzymes, due to the close relation existing between the atomic structure and the functionality. The Cu–isoleucine bond is considered as a good model system to attain a better insight into the characteristics of naturally occurring copper metalloproteins. The surface structure of metal–amino acid complex could be considered as a more realistic model for real systems under biologic working conditions, since the molecular packing is decreased. In the surface, the structural constrains are reduced, keeping the structural capability of surface complex to change as a function of the surrounding environment. In this work, we present a surface X-ray diffraction study on Cu–isoleucine complex under different ambient conditions. Cu(Ile) 2 crystals of about 5 mm × 5 mm × 1 mm have been growth, by seeding method in a supersaturated solution, presenting a surface of high quality. The sample for the surface diffraction study was mounted on a cell specially designed for solid/liquid or solid/gas interface analysis. The Cu–isoleucine crystal was measured under a protective dry N 2 gas flow and in contact with a saturated metal amino acid solution. The bulk and the surface signals were compared, showing different atomic structures. In both cases, from surface diffraction data, it is observed that the atomic structure of the top layer undergoes a clear structural deformation. A non-uniform surface relaxation is observed producing an inhomogeneous displacement of the surface atoms towards the surface normal.

  3. Verification of Triple Modular Redundancy Insertion for Reliable and Trusted Systems

    Science.gov (United States)

    Berg, Melanie; LaBel, Kenneth

    2016-01-01

    If a system is required to be protected using triple modular redundancy (TMR), improper insertion can jeopardize the reliability and security of the system. Due to the complexity of the verification process and the complexity of digital designs, there are currently no available techniques that can provide complete and reliable confirmation of TMR insertion. We propose a method for TMR insertion verification that satisfies the process for reliable and trusted systems.

  4. DESIGN INFORMATION VERIFICATION FOR NUCLEAR SAFEGUARDS

    Energy Technology Data Exchange (ETDEWEB)

    Robert S. Bean; Richard R. M. Metcalf; Phillip C. Durst

    2009-07-01

    A critical aspect of international safeguards activities performed by the International Atomic Energy Agency (IAEA) is the verification that facility design and construction (including upgrades and modifications) do not create opportunities for nuclear proliferation. These Design Information Verification activities require that IAEA inspectors compare current and past information about the facility to verify the operator’s declaration of proper use. The actual practice of DIV presents challenges to the inspectors due to the large amount of data generated, concerns about sensitive or proprietary data, the overall complexity of the facility, and the effort required to extract just the safeguards relevant information. Planned and anticipated facilities will (especially in the case of reprocessing plants) be ever larger and increasingly complex, thus exacerbating the challenges. This paper reports the results of a workshop held at the Idaho National Laboratory in March 2009, which considered technologies and methods to address these challenges. The use of 3D Laser Range Finding, Outdoor Visualization System, Gamma-LIDAR, and virtual facility modeling, as well as methods to handle the facility data issues (quantity, sensitivity, and accessibility and portability for the inspector) were presented. The workshop attendees drew conclusions about the use of these techniques with respect to successfully employing them in an operating environment, using a Fuel Conditioning Facility walk-through as a baseline for discussion.

  5. Hypervelocity Wind Tunnel No. 9 Mach 7 Thermal Structural Facility Verification and Calibration

    National Research Council Canada - National Science Library

    Lafferty, John

    1996-01-01

    This report summarizes the verification and calibration of the new Mach 7 Thermal Structural Facility located at the White Oak, Maryland, site of the Dahlgren Division, Naval Surface Warfare Center...

  6. Chemical functionalization of crystalline silicon surface with complexes of type (M3 (Dpa) 4X2) for the development of electronic devices

    International Nuclear Information System (INIS)

    Sanchez Zamora, Maria Alejandra

    2012-01-01

    New surfaces on crystalline silicon (100) diamines have been developed. The diamines 4-aminopyridine, 4-aminomethylpyridine and 1,12-dodecildiame, and self-assembled surfaces Si-diamine-metallic complexes, with cooper (II) acetate and trimetal Cu 3 (dpa) 4 CI 2 were studied. These surfaces are characterized with X-ray photoelectron spectroscopy (XPS), chemical force microscopy (CFM), by contact angle and cyclic voltammetry (CV). The XPS has suggested the formation of diamines monolayers with covalent binding to crystalline silicon, and modification of these surfaces, with metal complexes by coordination chemistry. The CFM has confirmed that surfaces are modified with diamines and cooper (II) acetate, and that were determined different chemical forces according to the change. The contact angle has been suggested that the functionalized surface with 4-aminomethylpyridine has had similar basicity to 1,12-dodecildiame, and more than 4-aminopyridine. This implies that the coordination with metallics complexes is benefited with 4-aminopyridine, which in turn is reflected with electrochemical data. Cyclic voltammetry analysis have showed that silicon surfaces with 4-aminomethylpyridine and 4-aminopyridine with cooper (II) acetate and trimetal have been electrochemically active. Thus, the surfaces could to have interesting applications in molecular electronics. (author) [es

  7. Verification and Diagnostics Framework in ATLAS Trigger/DAQ

    CERN Document Server

    Barczyk, M.; Caprini, M.; Da Silva Conceicao, J.; Dobson, M.; Flammer, J.; Jones, R.; Kazarov, A.; Kolos, S.; Liko, D.; Lucio, L.; Mapelli, L.; Soloviev, I.; Hart, R.; Amorim, A.; Klose, D.; Lima, J.; Pedro, J.; Wolters, H.; Badescu, E.; Alexandrov, I.; Kotov, V.; Mineev, M.; Ryabov, Yu.; Ryabov, Yu.

    2003-01-01

    Trigger and data acquisition (TDAQ) systems for modern HEP experiments are composed of thousands of hardware and software components depending on each other in a very complex manner. Typically, such systems are operated by non-expert shift operators, which are not aware of system functionality details. It is therefore necessary to help the operator to control the system and to minimize system down-time by providing knowledge-based facilities for automatic testing and verification of system components and also for error diagnostics and recovery. For this purpose, a verification and diagnostic framework was developed in the scope of ATLAS TDAQ. The verification functionality of the framework allows developers to configure simple low-level tests for any component in a TDAQ configuration. The test can be configured as one or more processes running on different hosts. The framework organizes tests in sequences, using knowledge about components hierarchy and dependencies, and allowing the operator to verify the fun...

  8. A static analysis tool set for assembler code verification

    International Nuclear Information System (INIS)

    Dhodapkar, S.D.; Bhattacharjee, A.K.; Sen, Gopa

    1991-01-01

    Software Verification and Validation (V and V) is an important step in assuring reliability and quality of the software. The verification of program source code forms an important part of the overall V and V activity. The static analysis tools described here are useful in verification of assembler code. The tool set consists of static analysers for Intel 8086 and Motorola 68000 assembly language programs. The analysers examine the program source code and generate information about control flow within the program modules, unreachable code, well-formation of modules, call dependency between modules etc. The analysis of loops detects unstructured loops and syntactically infinite loops. Software metrics relating to size and structural complexity are also computed. This report describes the salient features of the design, implementation and the user interface of the tool set. The outputs generated by the analyser are explained using examples taken from some projects analysed by this tool set. (author). 7 refs., 17 figs

  9. Neighbors Based Discriminative Feature Difference Learning for Kinship Verification

    DEFF Research Database (Denmark)

    Duan, Xiaodong; Tan, Zheng-Hua

    2015-01-01

    In this paper, we present a discriminative feature difference learning method for facial image based kinship verification. To transform feature difference of an image pair to be discriminative for kinship verification, a linear transformation matrix for feature difference between an image pair...... than the commonly used feature concatenation, leading to a low complexity. Furthermore, there is no positive semi-definitive constrain on the transformation matrix while there is in metric learning methods, leading to an easy solution for the transformation matrix. Experimental results on two public...... databases show that the proposed method combined with a SVM classification method outperforms or is comparable to state-of-the-art kinship verification methods. © Springer International Publishing AG, Part of Springer Science+Business Media...

  10. Knowledge base verification based on enhanced colored petri net

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Hyun; Seong, Poong Hyun [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1997-12-31

    Verification is a process aimed at demonstrating whether a system meets it`s specified requirements. As expert systems are used in various applications, the knowledge base verification of systems takes an important position. The conventional Petri net approach that has been studied recently in order to verify the knowledge base is found that it is inadequate to verify the knowledge base of large and complex system, such as alarm processing system of nuclear power plant. Thus, we propose an improved method that models the knowledge base as enhanced colored Petri net. In this study, we analyze the reachability and the error characteristics of the knowledge base and apply the method to verification of simple knowledge base. 8 refs., 4 figs. (Author)

  11. Formal development and verification of a distributed railway control system

    DEFF Research Database (Denmark)

    Haxthausen, Anne Elisabeth; Peleska, J.

    2000-01-01

    specifications which are transformed into directly implementable distributed control processes by applying a series of refinement and verification steps. Concrete safety requirements are derived from an abstract version that can be easily validated with respect to soundness and completeness. Complexity......The authors introduce the concept for a distributed railway control system and present the specification and verification of the main algorithm used for safe distributed control. Our design and verification approach is based on the RAISE method, starting with highly abstract algebraic...... is further reduced by separating the system model into a domain model and a controller model. The domain model describes the physical system in absence of control and the controller model introduces the safety-related control mechanisms as a separate entity monitoring observables of the physical system...

  12. Knowledge base verification based on enhanced colored petri net

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Hyun; Seong, Poong Hyun [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1998-12-31

    Verification is a process aimed at demonstrating whether a system meets it`s specified requirements. As expert systems are used in various applications, the knowledge base verification of systems takes an important position. The conventional Petri net approach that has been studied recently in order to verify the knowledge base is found that it is inadequate to verify the knowledge base of large and complex system, such as alarm processing system of nuclear power plant. Thus, we propose an improved method that models the knowledge base as enhanced colored Petri net. In this study, we analyze the reachability and the error characteristics of the knowledge base and apply the method to verification of simple knowledge base. 8 refs., 4 figs. (Author)

  13. Sorption of trivalent lanthanides and actinides onto montmorillonite: Macroscopic, thermodynamic and structural evidence for ternary hydroxo and carbonato surface complexes on multiple sorption sites.

    Science.gov (United States)

    Fernandes, M Marques; Scheinost, A C; Baeyens, B

    2016-08-01

    The credibility of long-term safety assessments of radioactive waste repositories may be greatly enhanced by a molecular level understanding of the sorption processes onto individual minerals present in the near- and far-fields. In this study we couple macroscopic sorption experiments to surface complexation modelling and spectroscopic investigations, including extended X-ray absorption fine structure (EXAFS) and time-resolved laser fluorescence spectroscopies (TRLFS), to elucidate the uptake mechanism of trivalent lanthanides and actinides (Ln/An(III)) by montmorillonite in the absence and presence of dissolved carbonate. Based on the experimental sorption isotherms for the carbonate-free system, the previously developed 2 site protolysis non electrostatic surface complexation and cation exchange (2SPNE SC/CE) model needed to be complemented with an additional surface complexation reaction onto weak sites. The fitting of sorption isotherms in the presence of carbonate required refinement of the previously published model by reducing the strong site capacity and by adding the formation of Ln/An(III)-carbonato complexes both on strong and weak sites. EXAFS spectra of selected Am samples and TRLFS spectra of selected Cm samples corroborate the model assumptions by showing the existence of different surface complexation sites and evidencing the formation of Ln/An(III) carbonate surface complexes. In the absence of carbonate and at low loadings, Ln/An(III) form strong inner-sphere complexes through binding to three Al(O,OH)6 octahedra, most likely by occupying vacant sites in the octahedral layers of montmorillonite, which are exposed on {010} and {110} edge faces. At higher loadings, Ln/An(III) binds to only one Al octahedron, forming a weaker, edge-sharing surface complex. In the presence of carbonate, we identified a ternary mono- or dicarbonato Ln/An(III) complex binding directly to one Al(O,OH)6 octahedron, revealing that type-A ternary complexes form with the one

  14. Independent Verification Final Summary Report for the David Witherspoon, Inc. 1630 Site Knoxville, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    P.C. Weaver

    2009-04-29

    The primary objective of the independent verification was to determine if BJC performed the appropriate actions to meet the specified “hot spot” cleanup criteria of 500 picocuries per gram (pCi/g) uranium-238 (U-238) in surface soil. Specific tasks performed by the independent verification team (IVT) to satisfy this objective included: 1) performing radiological walkover surveys, and 2) collecting soil samples for independent analyses. The independent verification (IV) efforts were designed to evaluate radioactive contaminants (specifically U-238) in the exposed surfaces below one foot of the original site grade, given that the top one foot layer of soil on the site was removed in its entirety.

  15. Independent Verification Final Summary Report for the David Witherspoon, Inc. 1630 Site Knoxville, Tennessee

    International Nuclear Information System (INIS)

    Weaver, P.C.

    2009-01-01

    The primary objective of the independent verification was to determine if BJC performed the appropriate actions to meet the specified 'hot spot' cleanup criteria of 500 picocuries per gram (pCi/g) uranium-238 (U-238) in surface soil. Specific tasks performed by the independent verification team (IVT) to satisfy this objective included: (1) performing radiological walkover surveys, and (2) collecting soil samples for independent analyses. The independent verification (IV) efforts were designed to evaluate radioactive contaminants (specifically U-238) in the exposed surfaces below one foot of the original site grade, given that the top one foot layer of soil on the site was removed in its entirety.

  16. DIMENSIONAL VERIFICATION AND QUALITY CONTROL OF IMPLANTS PRODUCED BY ADDITIVE MANUFACTURING

    Directory of Open Access Journals (Sweden)

    Teodor Toth

    2015-07-01

    Full Text Available Purpose: Development of computer technology and alternative manufacturing methods in form of additive manufacturing leads to the manufacture of products with complex shapes. In the field of medicine they include, inter alia, custom-made implants manufactured for a particular patient, such as cranial implants, maxillofacial implants, etc. With regard to the fact that such implants are inserted into a patient’s body, it is necessary to perform the verification, including the shape and dimensional verification. The article deals with the application of the industrial computer tomography within the process of inspection and verification of selected custom-made implant types.Methodology/Approach: The Department of Biomedical Engineering and Measurement performs the verification of medicinal products manufactured by the additive manufacturing technologies from the Ti-6Al-4V (Grade 5 titanium alloy, using the coordinate measuring machine Carl Zeiss Contura G2 and the industrial computed tomography machine Carl Zeiss Metrotom 1500. These equipment fulfil the requirements for the identification and evaluation of dimensions of both, the external and the internal structures. Findings: The article presents the possibilities of the computed tomography utilisation in the inspection of individual implant manufacture using the additive manufacturing technologies. The results indicate that with the adjustment of appropriate input parameters (alignment, this technology is appropriate for the analysis of shape deviations, when compared with the CAD model.Research Limitation/implication: With the increasing distance of measured object from X-ray source, the machine’s resolution function decreases. Decreasing of resolution has a minor impact on the measured dimensions (relatively high tolerances, but has a significant impact on the evaluation of porosity and inclusions. Originality/Value of paper: Currently, the verification of a manufactured implant  can be

  17. Crustal seismicity associated to rpid surface uplift at Laguna del Maule Volcanic Complex, Southern Volcanic Zone of the Andes

    Science.gov (United States)

    Cardona, Carlos; Tassara, Andrés; Gil-Cruz, Fernando; Lara, Luis; Morales, Sergio; Kohler, Paulina; Franco, Luis

    2018-03-01

    Laguna del Maule Volcanic Complex (LMVC, Southern Andes of Chile) has been experiencing large rates (ca. 30 cm/yr) of surface uplift as detected since 2008 by satellite geodetic measurements. Previous works have modeled the source of this deformation as an inflating rectangular sub-horizontal sill underlying LMVC at 5 km depth, which is supposedly related to an active process of magmatic replenishment of a shallow silicic reservoir. However little is known about the tectonic context on which this activity is taking place, particularly its relation with crustal seismicity that could help understanding and monitoring the current deformation process. Here we present the first detailed characterization of the seismic activity taking place at LMVC and integrate it with structural data acquired in the field in order to illuminate the possible connection between the ongoing process of surface uplift and the activation of crustal faults. Our main finding is the recognition of repetitive volcano-tectonic (VT) seismic swarms that occur periodically between 2011 and 2014 near the SW corner of the sill modeled by InSAR studies. A cross-correlation analysis of the waveforms recorded for these VT events allows identifying three different seismic families. Families F1 and F3 share some common features in the stacked waveform and its locations, which markedly differ from those of family F2. Swarms belonging to this later family are more energetic and its energy was increasing since 2011 to a peak in January 2013, which coincide with maximum vertical velocities detected by local GPS stations. This points to a common process relating both phenomena. The location of VT seismic swarms roughly coincides with the intersection of a NE-SW lineament with a WNW-ESE lineament. The former shows clear field evidences of dextral strike-slip that are fully consistent with one nodal plane of focal mechanism for well-recorded F2 events. The conjugate nodal plane of these focal mechanisms could

  18. Remarkable fluorescence enhancement versus complex formation of cationic porphyrins on the surface of ZnO nanoparticles

    KAUST Repository

    Aly, Shawkat Mohammede

    2014-06-12

    Fluorescence enhancement of organic fluorophores shows tremendous potential to improve image contrast in fluorescence-based bioimaging. Here, we present an experimental study of the interaction of two cationic porphyrins, meso-tetrakis(1-methylpyridinium-4-yl)porphyrin chloride (TMPyP) and meso-tetrakis(4-N,N,N-trimethylanilinium)porphyrin chloride (TMAP), with cationic surfactant-stabilized zinc oxide nanoparticles (ZnO NPs) based on several steady-state and time-resolved techniques. We show the first experimental measurements demonstrating a clear transition from pronounced fluorescence enhancement to charge transfer (CT) complex formation by simply changing the nature and location of the positive charge of the meso substituent of the cationic porphyrins. For TMPyP, we observe a sixfold increase in the fluorescence intensity of TMPyP upon addition of ZnO NPs. Our experimental results indicate that the electrostatic binding of TMPyP with the surface of ZnO NPs increases the symmetry of the porphyrin macrocycle. This electronic communication hinders the rotational relaxation of the meso unit and/or decreases the intramolecular CT character between the cavity and the meso substituent of the porphyrin, resulting in the enhancement of the intensity of the fluorescence. For TMAP, on the other hand, the different type and nature of the positive charge resulting in the development of the CT band arise from the interaction with the surface of ZnO NPs. This observation is confirmed by the femtosecond transient absorption spectroscopy, which provides clear spectroscopic signatures of photoinduced electron transfer from TMAP to ZnO NPs. © 2014 American Chemical Society.

  19. Challenges for effective WMD verification

    International Nuclear Information System (INIS)

    Andemicael, B.

    2006-01-01

    Effective verification is crucial to the fulfillment of the objectives of any disarmament treaty, not least as regards the proliferation of weapons of mass destruction (WMD). The effectiveness of the verification package depends on a number of factors, some inherent in the agreed structure and others related to the type of responses demanded by emerging challenges. The verification systems of three global agencies-the IAEA, the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO, currently the Preparatory Commission), and the Organization for the Prohibition of Chemical Weapons (OPCW)-share similarities in their broad objectives of confidence-building and deterrence by assuring members that rigorous verification would deter or otherwise detect non-compliance. Yet they are up against various constraints and other issues, both internal and external to the treaty regime. These constraints pose major challenges to the effectiveness and reliability of the verification operations. In the nuclear field, the IAEA safeguards process was the first to evolve incrementally from modest Statute beginnings to a robust verification system under the global Treaty on the Non-Proliferation of Nuclear Weapons (NPT). The nuclear non-proliferation regime is now being supplemented by a technology-intensive verification system of the nuclear test-ban treaty (CTBT), a product of over three decades of negotiation. However, there still remain fundamental gaps and loopholes in the regime as a whole, which tend to diminish the combined effectiveness of the IAEA and the CTBT verification capabilities. He three major problems are (a) the lack of universality of membership, essentially because of the absence of three nuclear weapon-capable States-India, Pakistan and Israel-from both the NPT and the CTBT, (b) the changes in US disarmament policy, especially in the nuclear field, and (c) the failure of the Conference on Disarmament to conclude a fissile material cut-off treaty. The world is

  20. Disarmament Verification - the OPCW Experience

    International Nuclear Information System (INIS)

    Lodding, J.

    2010-01-01

    The Chemical Weapons Convention is the only multilateral treaty that bans completely an entire category of weapons of mass destruction under international verification arrangements. Possessor States, i.e. those that have chemical weapons stockpiles at the time of becoming party to the CWC, commit to destroying these. All States undertake never to acquire chemical weapons and not to help other States acquire such weapons. The CWC foresees time-bound chemical disarmament. The deadlines for destruction for early entrants to the CWC are provided in the treaty. For late entrants, the Conference of States Parties intervenes to set destruction deadlines. One of the unique features of the CWC is thus the regime for verifying destruction of chemical weapons. But how can you design a system for verification at military sites, while protecting military restricted information? What degree of assurance is considered sufficient in such circumstances? How do you divide the verification costs? How do you deal with production capability and initial declarations of existing stockpiles? The founders of the CWC had to address these and other challenges in designing the treaty. Further refinement of the verification system has followed since the treaty opened for signature in 1993 and since inspection work was initiated following entry-into-force of the treaty in 1997. Most of this work concerns destruction at the two large possessor States, Russia and the United States. Perhaps some of the lessons learned from the OPCW experience may be instructive in a future verification regime for nuclear weapons. (author)

  1. Verification of Chemical Weapons Destruction

    International Nuclear Information System (INIS)

    Lodding, J.

    2010-01-01

    The Chemical Weapons Convention is the only multilateral treaty that bans completely an entire category of weapons of mass destruction under international verification arrangements. Possessor States, i.e. those that have chemical weapons stockpiles at the time of becoming party to the CWC, commit to destroying these. All States undertake never to acquire chemical weapons and not to help other States acquire such weapons. The CWC foresees time-bound chemical disarmament. The deadlines for destruction for early entrants to the CWC are provided in the treaty. For late entrants, the Conference of States Parties intervenes to set destruction deadlines. One of the unique features of the CWC is thus the regime for verifying destruction of chemical weapons. But how can you design a system for verification at military sites, while protecting military restricted information? What degree of assurance is considered sufficient in such circumstances? How do you divide the verification costs? How do you deal with production capability and initial declarations of existing stockpiles? The founders of the CWC had to address these and other challenges in designing the treaty. Further refinement of the verification system has followed since the treaty opened for signature in 1993 and since inspection work was initiated following entry-into-force of the treaty in 1997. Most of this work concerns destruction at the two large possessor States, Russia and the United States. Perhaps some of the lessons learned from the OPCW experience may be instructive in a future verification regime for nuclear weapons. (author)

  2. Spatial Evaluation and Verification of Earthquake Simulators

    Science.gov (United States)

    Wilson, John Max; Yoder, Mark R.; Rundle, John B.; Turcotte, Donald L.; Schultz, Kasey W.

    2017-06-01

    In this paper, we address the problem of verifying earthquake simulators with observed data. Earthquake simulators are a class of computational simulations which attempt to mirror the topological complexity of fault systems on which earthquakes occur. In addition, the physics of friction and elastic interactions between fault elements are included in these simulations. Simulation parameters are adjusted so that natural earthquake sequences are matched in their scaling properties. Physically based earthquake simulators can generate many thousands of years of simulated seismicity, allowing for a robust capture of the statistical properties of large, damaging earthquakes that have long recurrence time scales. Verification of simulations against current observed earthquake seismicity is necessary, and following past simulator and forecast model verification methods, we approach the challenges in spatial forecast verification to simulators; namely, that simulator outputs are confined to the modeled faults, while observed earthquake epicenters often occur off of known faults. We present two methods for addressing this discrepancy: a simplistic approach whereby observed earthquakes are shifted to the nearest fault element and a smoothing method based on the power laws of the epidemic-type aftershock (ETAS) model, which distributes the seismicity of each simulated earthquake over the entire test region at a decaying rate with epicentral distance. To test these methods, a receiver operating characteristic plot was produced by comparing the rate maps to observed m>6.0 earthquakes in California since 1980. We found that the nearest-neighbor mapping produced poor forecasts, while the ETAS power-law method produced rate maps that agreed reasonably well with observations.

  3. Resonance Raman and surface-enhanced resonance Raman spectra of LH2 antenna complex from Rhodobacter sphaeroides and Ectothiorhodospira sp. excited in the Qx and Qy transitions.

    Science.gov (United States)

    Chumanov, G; Picorel, R; Ortiz de Zarate, I; Cotton, T M; Seibert, M

    2000-05-01

    Well-resolved vibrational spectra of LH2 complex isolated from two photosynthetic bacteria, Rhodobacter sphaeroides and Ectothiorhodospira sp., were obtained using surface-enhanced resonance Raman scattering (SERRS) exciting into the Qx and the Qy transitions of bacteriochlorophyll a. High-quality SERRS spectra in the Qy region were accessible because the strong fluorescence background was quenched near the roughened Ag surface. A comparison of the spectra obtained with 590 nm and 752 nm excitation in the mid- and low-frequency regions revealed spectral differences between the two LH2 complexes as well as between the LH2 complexes and isolated bacteriochlorophyll a. Because peripheral modes of pigments contribute mainly to the low-frequency spectral region, frequencies and intensities of many vibrational bands in this region are affected by interactions with the protein. The results demonstrate that the microenvironment surrounding the pigments within the two LH2 complexes is somewhat different, despite the fact that the complexes exhibit similar electronic absorption spectra. These differences are most probably due to specific pigment-pigment and pigment-protein interactions within the LH2 complexes, and the approach might be useful for addressing subtle static and dynamic structural variances between pigment-protein complexes from different sources or in complexes altered chemically or genetically.

  4. Bloch Surface Waves Biosensors for High Sensitivity Detection of Soluble ERBB2 in a Complex Biological Environment.

    Science.gov (United States)

    Sinibaldi, Alberto; Sampaoli, Camilla; Danz, Norbert; Munzert, Peter; Sonntag, Frank; Centola, Fabio; Occhicone, Agostino; Tremante, Elisa; Giacomini, Patrizio; Michelotti, Francesco

    2017-08-17

    We report on the use of one-dimensional photonic crystals to detect clinically relevant concentrations of the cancer biomarker ERBB2 in cell lysates. Overexpression of the ERBB2 protein is associated with aggressive breast cancer subtypes. To detect soluble ERBB2, we developed an optical set-up which operates in both label-free and fluorescence modes. The detection approach makes use of a sandwich assay, in which the one-dimensional photonic crystals sustaining Bloch surface waves are modified with monoclonal antibodies, in order to guarantee high specificity during the biological recognition. We present the results of exemplary protein G based label-free assays in complex biological matrices, reaching an estimated limit of detection of 0.5 ng/mL. On-chip and chip-to-chip variability of the results is addressed too, providing repeatability rates. Moreover, results on fluorescence operation demonstrate the capability to perform high sensitive cancer biomarker assays reaching a resolution of 0.6 ng/mL, without protein G assistance. The resolution obtained in both modes meets international guidelines and recommendations (15 ng/mL) for ERBB2 quantification assays, providing an alternative tool to phenotype and diagnose molecular cancer subtypes.

  5. CASL Verification and Validation Plan

    Energy Technology Data Exchange (ETDEWEB)

    Mousseau, Vincent Andrew [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Dinh, Nam [North Carolina State Univ., Raleigh, NC (United States)

    2016-06-30

    This report documents the Consortium for Advanced Simulation of LWRs (CASL) verification and validation plan. The document builds upon input from CASL subject matter experts, most notably the CASL Challenge Problem Product Integrators, CASL Focus Area leaders, and CASL code development and assessment teams. This document will be a living document that will track progress on CASL to do verification and validation for both the CASL codes (including MPACT, CTF, BISON, MAMBA) and for the CASL challenge problems (CIPS, PCI, DNB). The CASL codes and the CASL challenge problems are at differing levels of maturity with respect to validation and verification. The gap analysis will summarize additional work that needs to be done. Additional VVUQ work will be done as resources permit. This report is prepared for the Department of Energy’s (DOE’s) CASL program in support of milestone CASL.P13.02.

  6. Technical challenges for dismantlement verification

    International Nuclear Information System (INIS)

    Olinger, C.T.; Stanbro, W.D.; Johnston, R.G.; Nakhleh, C.W.; Dreicer, J.S.

    1997-01-01

    In preparation for future nuclear arms reduction treaties, including any potential successor treaties to START I and II, the authors have been examining possible methods for bilateral warhead dismantlement verification. Warhead dismantlement verification raises significant challenges in the political, legal, and technical arenas. This discussion will focus on the technical issues raised by warhead arms controls. Technical complications arise from several sources. These will be discussed under the headings of warhead authentication, chain-of-custody, dismantlement verification, non-nuclear component tracking, component monitoring, and irreversibility. The authors will discuss possible technical options to address these challenges as applied to a generic dismantlement and disposition process, in the process identifying limitations and vulnerabilities. They expect that these considerations will play a large role in any future arms reduction effort and, therefore, should be addressed in a timely fashion

  7. Utterance Verification for Text-Dependent Speaker Recognition

    DEFF Research Database (Denmark)

    Kinnunen, Tomi; Sahidullah, Md; Kukanov, Ivan

    2016-01-01

    Text-dependent automatic speaker verification naturally calls for the simultaneous verification of speaker identity and spoken content. These two tasks can be achieved with automatic speaker verification (ASV) and utterance verification (UV) technologies. While both have been addressed previously...

  8. Refined ab initio intermolecular ground-state potential energy surface for the He-C2H2 van der Waals complex

    DEFF Research Database (Denmark)

    Fernández, Berta; Henriksen, Christian; Farrelly, David

    2013-01-01

    A refined CCSD(T) intermolecular potential energy surface is developed for the He-C2H2 van der Waals complex. For this, 206 points on the intermolecular potential energy surface, evaluated using the CCSD(T) method and the aug-cc-pVQZ basis set extended with a set of 3s3p2d1f1g midbond functions...

  9. Research on key technology of the verification system of steel rule based on vision measurement

    Science.gov (United States)

    Jia, Siyuan; Wang, Zhong; Liu, Changjie; Fu, Luhua; Li, Yiming; Lu, Ruijun

    2018-01-01

    The steel rule plays an important role in quantity transmission. However, the traditional verification method of steel rule based on manual operation and reading brings about low precision and low efficiency. A machine vison based verification system of steel rule is designed referring to JJG1-1999-Verificaiton Regulation of Steel Rule [1]. What differentiates this system is that it uses a new calibration method of pixel equivalent and decontaminates the surface of steel rule. Experiments show that these two methods fully meet the requirements of the verification system. Measuring results strongly prove that these methods not only meet the precision of verification regulation, but also improve the reliability and efficiency of the verification system.

  10. Biometric Technologies and Verification Systems

    CERN Document Server

    Vacca, John R

    2007-01-01

    Biometric Technologies and Verification Systems is organized into nine parts composed of 30 chapters, including an extensive glossary of biometric terms and acronyms. It discusses the current state-of-the-art in biometric verification/authentication, identification and system design principles. It also provides a step-by-step discussion of how biometrics works; how biometric data in human beings can be collected and analyzed in a number of ways; how biometrics are currently being used as a method of personal identification in which people are recognized by their own unique corporal or behavior

  11. IMRT plan verification in radiotherapy

    International Nuclear Information System (INIS)

    Vlk, P.

    2006-01-01

    This article describes the procedure for verification of IMRT (Intensity modulated radiation therapy) plan, which is used in the Oncological Institute of St. Elisabeth in Bratislava. It contains basic description of IMRT technology and developing a deployment plan for IMRT planning system CORVUS 6.0, the device Mimic (Multilammelar intensity modulated collimator) and the overall process of verifying the schedule created. The aim of verification is particularly good control of the functions of MIMIC and evaluate the overall reliability of IMRT planning. (author)

  12. K Basins Field Verification Program

    International Nuclear Information System (INIS)

    Booth, H.W.

    1994-01-01

    The Field Verification Program establishes a uniform and systematic process to ensure that technical information depicted on selected engineering drawings accurately reflects the actual existing physical configuration. This document defines the Field Verification Program necessary to perform the field walkdown and inspection process that identifies the physical configuration of the systems required to support the mission objectives of K Basins. This program is intended to provide an accurate accounting of the actual field configuration by documenting the as-found information on a controlled drawing

  13. Daily Based Morgan–Morgan–Finney (DMMF Model: A Spatially Distributed Conceptual Soil Erosion Model to Simulate Complex Soil Surface Configurations

    Directory of Open Access Journals (Sweden)

    Kwanghun Choi

    2017-04-01

    Full Text Available In this paper, we present the Daily based Morgan–Morgan–Finney model. The main processes in this model are based on the Morgan–Morgan–Finney soil erosion model, and it is suitable for estimating surface runoff and sediment redistribution patterns in seasonal climate regions with complex surface configurations. We achieved temporal flexibility by utilizing daily time steps, which is suitable for regions with concentrated seasonal rainfall. We introduce the proportion of impervious surface cover as a parameter to reflect its impacts on soil erosion through blocking water infiltration and protecting the soil from detachment. Also, several equations and sequences of sub-processes are modified from the previous model to better represent physical processes. From the sensitivity analysis using the Sobol’ method, the DMMF model shows the rational response to the input parameters which is consistent with the result from the previous versions. To evaluate the model performance, we applied the model to two potato fields in South Korea that had complex surface configurations using plastic covered ridges at various temporal periods during the monsoon season. Our new model shows acceptable performance for runoff and the sediment loss estimation ( NSE ≥ 0.63 , | PBIAS | ≤ 17.00 , and RSR ≤ 0.57 . Our findings demonstrate that the DMMF model is able to predict the surface runoff and sediment redistribution patterns for cropland with complex surface configurations.

  14. Monitoring/Verification Using DMS: TATP Example

    International Nuclear Information System (INIS)

    Kevin Kyle; Stephan Weeks

    2008-01-01

    Field-rugged and field-programmable differential mobility spectrometry (DMS) networks provide highly selective, universal monitoring of vapors and aerosols at detectable levels from persons or areas involved with illicit chemical/biological/explosives (CBE) production. CBE sensor motes used in conjunction with automated fast gas chromatography with DMS detection (GC/DMS) verification instrumentation integrated into situational operations management systems can be readily deployed and optimized for changing application scenarios. The feasibility of developing selective DMS motes for a 'smart dust' sampling approach with guided, highly selective, fast GC/DMS verification analysis is a compelling approach to minimize or prevent the illegal use of explosives or chemical and biological materials. DMS is currently one of the foremost emerging technologies for field separation and detection of gas-phase chemical species. This is due to trace-level detection limits, high selectivity, and small size. GC is the leading analytical method for the separation of chemical species in complex mixtures. Low-thermal-mass GC columns have led to compact, low-power field systems capable of complete analyses in 15-300 seconds. A collaborative effort optimized a handheld, fast GC/DMS, equipped with a non-rad ionization source, for peroxide-based explosive measurements

  15. Exploring inclusion complexes of ionic liquids with α- and β- cyclodextrin by NMR, IR, mass, density, viscosity, surface tension and conductance study

    Science.gov (United States)

    Barman, Biraj Kumar; Rajbanshi, Biplab; Yasmin, Ananya; Roy, Mahendra Nath

    2018-05-01

    The formation of the host-guest inclusion complexes of ionic liquids namely [BMIm]Cl and [HMIm]Cl with α-CD and β-CD were studied by means of physicochemical and spectroscopic methods. Conductivity and surface tension study were in good agreement with the 1H NMR and FT-IR studies which confirm the formation of the inclusion complexes. The Density and viscosity study also supported the formation of the ICs. Further the stoichiometry was determined 1:1 for each case and the association constants and thermodynamic parameters derived supported the most feasible formation of the [BMIm]Cl- β-CD inclusion complex.

  16. Shallow sub-surface structure of the central volcanic complex of Tenerife, Canary Islands: implications for the evolution and the recent reactivation of the Las Canadas caldera

    Energy Technology Data Exchange (ETDEWEB)

    Gottsmann, J [Department of Earth Sciences, University of Bristol, Wills Memorial Building, Queens Road, Bristol BS8 1RJ (United Kingdom); Camacho, A G; Fernandez, J [Instituto de Astronomia y Geodesia (CSIC-UCM), Ciudad Universitaria, Pza. de Ciencias, 3, 28040 Madrid (Spain); MartI, J [Institute of Earth Sciences ' Jaume Almera' , CSIC, Lluis Sole SabarIs s/n, Barcelona 08028 (Spain); Wooller, L; Rymer, H [Department of Earth and Environmental Sciences, Open University, Walton Hall, Milton Keynes, MK7 6AA (United Kingdom); GarcIa, A [Department of Volcanology, Museo Nacional de Ciencias Naturales, CSIC, C/ Jose Gutierrez Abascal, 2, 28006 Madrid (Spain)], E-mail: j.gottsmann@bristol.ac.uk

    2008-10-01

    We present a new local Bouguer anomaly map of the Central Volcanic Complex (CVC) of Tenerife, Spain. The high-density core of the CVC and the pronounced gravity low centred in the Las Canadas caldera (LCC) in greater detail than previously available. Mathematical construction of a subsurface model from the local anomaly data, employing a 3-D inversion enables mapping of the shallow structure beneath the complex, giving unprecedented insights into the sub-surface architecture of the complex, and shedding light on its evolution.

  17. Subsurface barrier verification technologies, informal report

    International Nuclear Information System (INIS)

    Heiser, J.H.

    1994-06-01

    One of the more promising remediation options available to the DOE waste management community is subsurface barriers. Some of the uses of subsurface barriers include surrounding and/or containing buried waste, as secondary confinement of underground storage tanks, to direct or contain subsurface contaminant plumes and to restrict remediation methods, such as vacuum extraction, to a limited area. To be most effective the barriers should be continuous and depending on use, have few or no breaches. A breach may be formed through numerous pathways including: discontinuous grout application, from joints between panels and from cracking due to grout curing or wet-dry cycling. The ability to verify barrier integrity is valuable to the DOE, EPA, and commercial sector and will be required to gain full public acceptance of subsurface barriers as either primary or secondary confinement at waste sites. It is recognized that no suitable method exists for the verification of an emplaced barrier's integrity. The large size and deep placement of subsurface barriers makes detection of leaks challenging. This becomes magnified if the permissible leakage from the site is low. Detection of small cracks (fractions of an inch) at depths of 100 feet or more has not been possible using existing surface geophysical techniques. Compounding the problem of locating flaws in a barrier is the fact that no placement technology can guarantee the completeness or integrity of the emplaced barrier. This report summarizes several commonly used or promising technologies that have been or may be applied to in-situ barrier continuity verification

  18. Diethylenetriamine/diamines/copper (II complexes [Cu(dien(NN]Br2: Synthesis, solvatochromism, thermal, electrochemistry, single crystal, Hirshfeld surface analysis and antibacterial activity

    Directory of Open Access Journals (Sweden)

    Fatima Abu Saleemh

    2017-09-01

    Full Text Available Two dicationic water soluble mixed triamine/diamine copper (II complexes, of general formula [Cu(dienNN]Br2 (1–2 [dien = diethelenetriamine and NN is en = ethylenediamine or Me4en = N,N′,N,N′-tetramethylethylenediamine] were prepared under ultrasonic mode with a relatively high yield. These complexes were characterized by elemental microanalysis, UV visible IR spectroscopy, and thermal and electrochemical techniques. In addition, complex 2 structure was solved by X-ray single crystal and Hirshfeld surface analysis. The complex exhibits a distorted square pyramidal coordination environment around Cu(II centre. The solvatochromism of the desired complexes was investigated in water and other suitable organic solvents. The results show that the Guttmann’s DN parameter values of the solvents have mainly contributed to the shift of the d–d absorption band towards the linear increase in the wavelength of the absorption maxima of the complexes. The complex 1 showed higher antibacterial activity against the studied microorganisms compared to complex 2. Both complexes revealed promising antibacterial activities.

  19. Likelihood-ratio-based biometric verification

    NARCIS (Netherlands)

    Bazen, A.M.; Veldhuis, Raymond N.J.

    2002-01-01

    This paper presents results on optimal similarity measures for biometric verification based on fixed-length feature vectors. First, we show that the verification of a single user is equivalent to the detection problem, which implies that for single-user verification the likelihood ratio is optimal.

  20. Likelihood Ratio-Based Biometric Verification

    NARCIS (Netherlands)

    Bazen, A.M.; Veldhuis, Raymond N.J.

    The paper presents results on optimal similarity measures for biometric verification based on fixed-length feature vectors. First, we show that the verification of a single user is equivalent to the detection problem, which implies that, for single-user verification, the likelihood ratio is optimal.

  1. inner-sphere complexation of cations at the rutile-water interface: A concise surface structural interpretation with the CD and MUSIC model

    Energy Technology Data Exchange (ETDEWEB)

    Ridley, Mora K. [Texas Tech University, Lubbock; Hiemstra, T [Oak Ridge National Laboratory (ORNL); Van Riemsdijk, Willem H. [Wageningen University and Research Centre, The Netherlands; Machesky, Michael L. [Illinois State Water Survey, Champaign, IL

    2009-01-01

    Acid base reactivity and ion-interaction between mineral surfaces and aqueous solutions is most frequently investigated at the macroscopic scale as a function of pH. Experimental data are then rationalized by a variety of surface complexation models. These models are thermodynamically based which in principle does not require a molecular picture. The models are typically calibrated to relatively simple solid-electrolyte solution pairs and may provide poor descriptions of complex multicomponent mineral aqueous solutions, including those found in natural environments. Surface complexation models may be improved by incorporating molecular-scale surface structural information to constrain the modeling efforts. Here, we apply a concise, molecularly-constrained surface complexation model to a diverse suite of surface titration data for rutile and thereby begin to address the complexity of multi-component systems. Primary surface charging curves in NaCl, KCl, and RbCl electrolyte media were fit simultaneously using a charge distribution (CD) and multisite complexation (MUSIC) model [Hiemstra T. and Van Riemsdijk W. H. (1996) A surface structural approach to ion adsorption: the charge distribution (CD) model. J. Colloid Interf. Sci. 179, 488 508], coupled with a Basic Stern layer description of the electric double layer. In addition, data for the specific interaction of Ca2+ and Sr2+ with rutile, in NaCl and RbCl media, were modeled. In recent developments, spectroscopy, quantum calculations, and molecular simulations have shown that electrolyte and divalent cations are principally adsorbed in various inner-sphere configurations on the rutile 110 surface [Zhang Z., Fenter P., Cheng L., Sturchio N. C., Bedzyk M. J., Pr edota M., Bandura A., Kubicki J., Lvov S. N., Cummings P. T., Chialvo A. A., Ridley M. K., Be ne zeth P., Anovitz L., Palmer D. A., Machesky M. L. and Wesolowski D. J. (2004) Ion adsorption at the rutile water interface: linking molecular and macroscopic

  2. Inner-sphere complexation of cations at the rutile-water interface: A concise surface structural interpretation with the CD and MUSIC model

    Science.gov (United States)

    Ridley, Moira K.; Hiemstra, Tjisse; van Riemsdijk, Willem H.; Machesky, Michael L.

    2009-04-01

    Acid-base reactivity and ion-interaction between mineral surfaces and aqueous solutions is most frequently investigated at the macroscopic scale as a function of pH. Experimental data are then rationalized by a variety of surface complexation models. These models are thermodynamically based which in principle does not require a molecular picture. The models are typically calibrated to relatively simple solid-electrolyte solution pairs and may provide poor descriptions of complex multi-component mineral-aqueous solutions, including those found in natural environments. Surface complexation models may be improved by incorporating molecular-scale surface structural information to constrain the modeling efforts. Here, we apply a concise, molecularly-constrained surface complexation model to a diverse suite of surface titration data for rutile and thereby begin to address the complexity of multi-component systems. Primary surface charging curves in NaCl, KCl, and RbCl electrolyte media were fit simultaneously using a charge distribution (CD) and multisite complexation (MUSIC) model [Hiemstra T. and Van Riemsdijk W. H. (1996) A surface structural approach to ion adsorption: the charge distribution (CD) model. J. Colloid Interf. Sci. 179, 488-508], coupled with a Basic Stern layer description of the electric double layer. In addition, data for the specific interaction of Ca 2+ and Sr 2+ with rutile, in NaCl and RbCl media, were modeled. In recent developments, spectroscopy, quantum calculations, and molecular simulations have shown that electrolyte and divalent cations are principally adsorbed in various inner-sphere configurations on the rutile 1 1 0 surface [Zhang Z., Fenter P., Cheng L., Sturchio N. C., Bedzyk M. J., Předota M., Bandura A., Kubicki J., Lvov S. N., Cummings P. T., Chialvo A. A., Ridley M. K., Bénézeth P., Anovitz L., Palmer D. A., Machesky M. L. and Wesolowski D. J. (2004) Ion adsorption at the rutile-water interface: linking molecular and macroscopic

  3. Modality Switching in a Property Verification Task: An ERP Study of What Happens When Candles Flicker after High Heels Click.

    Science.gov (United States)

    Collins, Jennifer; Pecher, Diane; Zeelenberg, René; Coulson, Seana

    2011-01-01

    The perceptual modalities associated with property words, such as flicker or click, have previously been demonstrated to affect subsequent property verification judgments (Pecher et al., 2003). Known as the conceptual modality switch effect, this finding supports the claim that brain systems for perception and action help subserve the representation of concepts. The present study addressed the cognitive and neural substrate of this effect by recording event-related potentials (ERPs) as participants performed a property verification task with visual or auditory properties in key trials. We found that for visual property verifications, modality switching was associated with an increased amplitude N400. For auditory verifications, switching led to a larger late positive complex. Observed ERP effects of modality switching suggest property words access perceptual brain systems. Moreover, the timing and pattern of the effects suggest perceptual systems impact the decision-making stage in the verification of auditory properties, and the semantic stage in the verification of visual properties.

  4. Future of monitoring and verification

    International Nuclear Information System (INIS)

    Wagenmakers, H.

    1991-01-01

    The organized verification entrusted to IAEA for the implementation of the NPT, of the Treaty of Tlatelolco and of the Treaty of Rarotonga, reaches reasonable standards. The current dispute with the Democratic People's Republic of Korea about the conclusion of a safeguards agreement with IAEA, by its exceptional nature, underscores rather than undermines the positive judgement to be passed on IAEA's overall performance. The additional task given to the Director General of IAEA under Security Council resolution 687 (1991) regarding Iraq's nuclear-weapons-usable material is particularly challenging. For the purposes of this paper, verification is defined as the process for establishing whether the States parties are complying with an agreement. In the final stage verification may lead into consideration of how to respond to non-compliance. Monitoring is perceived as the first level in the verification system. It is one generic form of collecting information on objects, activities or events and it involves a variety of instruments ranging from communications satellites to television cameras or human inspectors. Monitoring may also be used as a confidence-building measure

  5. Hot cell verification facility update

    International Nuclear Information System (INIS)

    Titzler, P.A.; Moffett, S.D.; Lerch, R.E.

    1985-01-01

    The Hot Cell Verification Facility (HCVF) provides a prototypic hot cell mockup to check equipment for functional and remote operation, and provides actual hands-on training for operators. The facility arrangement is flexible and assists in solving potential problems in a nonradioactive environment. HCVF has been in operation for six years, and the facility is a part of the Hanford Engineering Development Laboratory

  6. Static Verification for Code Contracts

    Science.gov (United States)

    Fähndrich, Manuel

    The Code Contracts project [3] at Microsoft Research enables programmers on the .NET platform to author specifications in existing languages such as C# and VisualBasic. To take advantage of these specifications, we provide tools for documentation generation, runtime contract checking, and static contract verification.

  7. Verification of safety critical software

    International Nuclear Information System (INIS)

    Son, Ki Chang; Chun, Chong Son; Lee, Byeong Joo; Lee, Soon Sung; Lee, Byung Chai

    1996-01-01

    To assure quality of safety critical software, software should be developed in accordance with software development procedures and rigorous software verification and validation should be performed. Software verification is the formal act of reviewing, testing of checking, and documenting whether software components comply with the specified requirements for a particular stage of the development phase[1]. New software verification methodology was developed and was applied to the Shutdown System No. 1 and 2 (SDS1,2) for Wolsung 2,3 and 4 nuclear power plants by Korea Atomic Energy Research Institute(KAERI) and Atomic Energy of Canada Limited(AECL) in order to satisfy new regulation requirements of Atomic Energy Control Boars(AECB). Software verification methodology applied to SDS1 for Wolsung 2,3 and 4 project will be described in this paper. Some errors were found by this methodology during the software development for SDS1 and were corrected by software designer. Outputs from Wolsung 2,3 and 4 project have demonstrated that the use of this methodology results in a high quality, cost-effective product. 15 refs., 6 figs. (author)

  8. Eggspectation : organic egg verification tool

    NARCIS (Netherlands)

    Ruth, van S.M.; Hoogenboom, L.A.P.

    2011-01-01

    In 2009 RIKILT conducted a study on about 2,000 eggs to evaluate three different analytical verification methods: carotenoid profiling, fatty acid profiling and isotope ratio mass spectrometry. The eggs were collected from about 50 Dutch farms. The selection was based on the farms’ location and

  9. Surface-Sensitive and Bulk Studies on the Complexation and Photosensitized Degradation of Catechol by Iron(III) as a Model for Multicomponent Aerosol Systems

    Science.gov (United States)

    Al-abadleh, H. A.; Tofan-Lazar, J.; Situm, A.; Ruffolo, J.; Slikboer, S.

    2013-12-01

    Surface water plays a crucial role in facilitating or inhibiting surface reactions in atmospheric aerosols. Little is known about the role of surface water in the complexation of organic molecules to transition metals in multicomponent aerosol systems. We will show results from real time diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) experiments for the in situ complexation of catechol to Fe(III) and its photosensitized degradation under dry and humid conditions. Catechol was chosen as a simple model for humic-like substances (HULIS) in aerosols and aged polyaromatic hydrocarbons (PAH). It has also been detected in secondary organic aerosols (SOA) formed from the reaction of hydroxyl radicals with benzene. Given the importance of the iron content in aerosols and its biogeochemistry, our studies were conducted using FeCl3. For comparison, these surface-sensitive studies were complemented with bulk aqueous ATR-FTIR, UV-vis, and HPLC measurements for structural, quantitative and qualitative information about complexes in the bulk, and potential degradation products. The implications of our studies on understanding interfacial and condensed phase chemistry relevant to multicomponent aerosols, water thin islands on buildings, and ocean surfaces containing transition metals will be discussed.

  10. Studies of surface complexation of H+, NpO2+, Co2+, Th4+ onto TiO2 and H+, UO22+ onto alumina

    International Nuclear Information System (INIS)

    Jakobsson, Anna-Maria; Albinsson, Yngve

    1998-11-01

    This report describes the determination of surface complexation reactions of some radionuclides on mineral oxides from sorption experiments and potentiometric titrations. The surface acidity constants of the mineral oxide have been determined using potentiometric titrations. A description and discussion of the extrapolation method used is included as well as the calibration method which is of uttermost importance for calculating the constants. In this report it is shown that the data close to pH pzc can not be used to calculate the apparent equilibrium constants since the assumption that either the positive or negative sites dominate gives rise to a pK app that approach infinity. Furthermore it is shown that it is a fair estimation to assume a linear relationship between the inner surface charge and the potential since pure titanium dioxide gives a pK app that has a linear dependence on the inner surface charge. Besides the surface acidity constants, the capacitance of the inner layer has been calculated from this linear dependence. The values of these agree well with other proposed in the literature. The sorption of cobalt, thorium and neptunyl ions onto titanium dioxide and uranyl ions onto alumina from aqueous solution was studied as a function of pH and ionic strength in a C0 2 free environment at moderate radionuclide concentrations. Two different experimental methods were employed; an on-line method in which samples withdrawn at a specific pH are separated and measured, and a batch method. There is no significant difference between the average results from the two methods, however the on-line method provides less scatter. Also, using this method we were able to study the desorption easily and thus the reversibility of the reactions. There is no difference in sorption between the different ionic strengths for Np, Th, Co and U ions. This indicates the formation of inner sphere complexes with the surface. Neptunyl ion forms a neutral complex with the titanium

  11. Remedial activities effectiveness verification in tailing areas.

    Science.gov (United States)

    Kluson, J; Thinova, L; Neznal, M; Svoboda, T

    2015-06-01

    The complex radiological study of the basin of sludge from the uranium ore mining and preprocessing was done. Air kerma rates (including its spectral analysis) at the reference height of 1 m above ground over the whole area were measured and radiation fields mapped during two measuring campaigns (years 2009 and 2014). K, U and Th concentrations in sludge and concentrations in depth profiles (including radon concentration and radon exhalation rates) in selected points were determined using gamma spectrometry for in situ as well as laboratory samples measurement. Results were used for the analysis, design evaluation and verification of the efficiency of the remediation measures. Efficiency of the sludge basin covering by the inert material was modelled using MicroShield code. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Remedial activities effectiveness verification in tailing areas

    International Nuclear Information System (INIS)

    Kluson, J.; Thinova, L.; Svoboda, T.; Neznal, M.

    2015-01-01

    The complex radiological study of the basin of sludge from the uranium ore mining and preprocessing was done. Air kerma rates (including its spectral analysis) at the reference height of 1 m above ground over the whole area were measured and radiation fields mapped during two measuring campaigns (years 2009 and 2014). K, U and Th concentrations in sludge and concentrations in depth profiles (including radon concentration and radon exhalation rates) in selected points were determined using gamma spectrometry for in situ as well as laboratory samples measurement. Results were used for the analysis, design evaluation and verification of the efficiency of the remediation measures. Efficiency of the sludge basin covering by the inert material was modelled using MicroShield code. (authors)

  13. Cyclophilin B mediates cyclosporin A incorporation in human blood T-lymphocytes through the specific binding of complexed drug to the cell surface.

    Science.gov (United States)

    Allain, F; Denys, A; Spik, G

    1996-07-15

    Cyclophilin B (CyPB) is a cyclosporin A (CsA)-binding protein located within intracellular vesicles and released in biological fluids. We recently reported the specific binding of this protein to T-cell surface receptor which is internalized even in the presence of CsA. These results suggest that CyPB might target the drug to lymphocytes and consequently modify its activity. To verify this hypothesis, we have first investigated the binding capacity and internalization of the CsA-CyPB complex in human peripheral blood T-lymphocytes and secondly compared the inhibitory effect of both free and CyPB-complexed CsA on the CD3-induced activation and proliferation of T-cells. Here, we present evidence that both the CsA-CyPB complex and free CyPB bind to the T-lymphocyte surface, with similar values of Kd and number of sites. At 37 degrees C, the complex is internalized but, in contrast to the protein, the drug is accumulated within the cell. Moreover, CyPB receptors are internalized together with the ligand and rapidly recycled to the cell surface. Finally, we demonstrate that CyPB-complexed CsA remains as efficient as uncomplexed CsA and that CyPB enhances the immunosuppressive activity of the drug. Taken together, our results support the hypothesis that surface CyPB receptors may be related to the selective and variable action of CsA, through specific binding and targeting of the CyPB-CsA complex to peripheral blood T-lymphocytes.

  14. CFD code verification and the method of manufactured solutions

    International Nuclear Information System (INIS)

    Pelletier, D.; Roache, P.J.

    2002-01-01

    This paper presents the Method of Manufactured Solutions (MMS) for CFD code verification. The MMS provides benchmark solutions for direct evaluation of the solution error. The best benchmarks are exact analytical solutions with sufficiently complex solution structure to ensure that all terms of the differential equations are exercised in the simulation. The MMS provides a straight forward and general procedure for generating such solutions. When used with systematic grid refinement studies, which are remarkably sensitive, the MMS provides strong code verification with a theorem-like quality. The MMS is first presented on simple 1-D examples. Manufactured solutions for more complex problems are then presented with sample results from grid convergence studies. (author)

  15. A study of compositional verification based IMA integration method

    Science.gov (United States)

    Huang, Hui; Zhang, Guoquan; Xu, Wanmeng

    2018-03-01

    The rapid development of avionics systems is driving the application of integrated modular avionics (IMA) systems. But meanwhile it is improving avionics system integration, complexity of system test. Then we need simplify the method of IMA system test. The IMA system supports a module platform that runs multiple applications, and shares processing resources. Compared with federated avionics system, IMA system is difficult to isolate failure. Therefore, IMA system verification will face the critical problem is how to test shared resources of multiple application. For a simple avionics system, traditional test methods are easily realizing to test a whole system. But for a complex system, it is hard completed to totally test a huge and integrated avionics system. Then this paper provides using compositional-verification theory in IMA system test, so that reducing processes of test and improving efficiency, consequently economizing costs of IMA system integration.

  16. In situ spectroscopic evidence for neptunium(V)-carbonate inner-sphere and outer-sphere ternary surface complexes on hematite surfaces.

    Science.gov (United States)

    Arai, Yuji; Moran, P B; Honeyman, B D; Davis, J A

    2007-06-01

    Np(V) surface speciation on hematite surfaces at pH 7-9 under pC2 = 10(-3.45) atm was investigated using X-ray absorption spectroscopy (XAS). In situ XAS analyses suggest that bis-carbonato inner-sphere and tris-carbonato outer-sphere ternary surface species coexist at the hematite-water interface at pH 7-8.8, and the fraction of outer-sphere species gradually increases from 27 to 54% with increasing pH from 7 to 8.8. The results suggest that the heretofore unknown Np(V)-carbonato ternary surface species may be important in predicting the fate and transport of Np(V) in the subsurface environment down gradient of high-level nuclear waste respositories.

  17. Hybrid Control and Verification of a Pulsed Welding Process

    DEFF Research Database (Denmark)

    Wisniewski, Rafal; Larsen, Jesper Abildgaard; Izadi-Zamanabadi, Roozbeh

    Currently systems, which are desired to control, are becoming more and more complex and classical control theory objectives, such as stability or sensitivity, are often not sufficient to cover the control objectives of the systems. In this paper it is shown how the dynamics of a pulsed welding...... process can be reformulated into a timed automaton hybrid setting and subsequently properties such as reachability and deadlock absence is verified by the simulation and verification tool UPPAAL....

  18. Modeling the dynamics of internal flooding - verification analysis

    International Nuclear Information System (INIS)

    Filipov, K.

    2011-01-01

    The results from conducted software WATERFOW's verification analysis, developed for the purposes of reactor building internal flooding analysis have been presented. For the purpose of benchmarking the integrated code MELCOR is selected. Considering the complex structure of reactor building, the sample tests were used to cover the characteristic points of the internal flooding analysis. The inapplicability of MELCOR to the internal flooding study has been proved

  19. SURVEY, REPRESENTATION AND ANALYSIS OF A WAR I COMPLEX SYSTEM OF SURFACE AND UNDERGROUND FORTIFICATIONS IN THE GRESTA VALLEY, ITALY

    Directory of Open Access Journals (Sweden)

    I. Salvador

    2012-09-01

    Full Text Available This work is part of a research on the use of terrestrial laser scanner, integrated with total station and GPS, for the documentation and comprehension of complex architectures in up-land sites. The research is performed in the framework of the project "Ambiente e Paesaggi dei siti di Altura Trentini" – APSAT (Environment and landscape of hill-top sites in Trentino, a multidisciplinary project focused on the evolution of hill-top anthropic system in the Trentino region, Italy. The study area is located in the Gresta Valley and this work concerns on the Nagià Grom site, fortified by the Austria-Hungarian Army during the World War I. The site has been interested by a significant restore operation of a large series of entrenches paths and fortifications in the last decade. The survey herein described has involved an area once interested by military barracks with Officers' Mess, water provision and by one of the biggest field kitchens discovered in the Trentino region. A second survey involved the tunnel connecting the ammunition depot to the artillery stations. The nature of such complex architectures, characterized by an irregular and composite 3D span leads, in general, to necessary simple surveys and representations and somehow to simplified studies too. The 3D point cloud, once filtered by the massive presence of dense vegetation, eventually constitutes a rich data set for further analyses on the spatial, geological, architectural and historical properties of the site. The analysis has been carried out on two different scales. At the architectural-scale, the comparison to historic photos has allowed to understand how the original structure of the barracks was made and to find building characters that now are lost. The on-site observation of the underground stratigraphic splices and their analysis in the 3D point cloud, e.g., spatial extension and slope, have permitted the understanding of the special excavation process guided by the

  20. Investigation of Navier-Stokes Code Verification and Design Optimization

    Science.gov (United States)

    Vaidyanathan, Rajkumar

    2004-01-01

    With rapid progress made in employing computational techniques for various complex Navier-Stokes fluid flow problems, design optimization problems traditionally based on empirical formulations and experiments are now being addressed with the aid of computational fluid dynamics (CFD). To be able to carry out an effective CFD-based optimization study, it is essential that the uncertainty and appropriate confidence limits of the CFD solutions be quantified over the chosen design space. The present dissertation investigates the issues related to code verification, surrogate model-based optimization and sensitivity evaluation. For Navier-Stokes (NS) CFD code verification a least square extrapolation (LSE) method is assessed. This method projects numerically computed NS solutions from multiple, coarser base grids onto a freer grid and improves solution accuracy by minimizing the residual of the discretized NS equations over the projected grid. In this dissertation, the finite volume (FV) formulation is focused on. The interplay between the xi concepts and the outcome of LSE, and the effects of solution gradients and singularities, nonlinear physics, and coupling of flow variables on the effectiveness of LSE are investigated. A CFD-based design optimization of a single element liquid rocket injector is conducted with surrogate models developed using response surface methodology (RSM) based on CFD solutions. The computational model consists of the NS equations, finite rate chemistry, and the k-6 turbulence closure. With the aid of these surrogate models, sensitivity and trade-off analyses are carried out for the injector design whose geometry (hydrogen flow angle, hydrogen and oxygen flow areas and oxygen post tip thickness) is optimized to attain desirable goals in performance (combustion length) and life/survivability (the maximum temperatures on the oxidizer post tip and injector face and a combustion chamber wall temperature). A preliminary multi-objective optimization

  1. Covalent attachment of pyridine-type molecules to glassy carbon surfaces by electrochemical reduction of in situ generated diazonium salts. Formation of ruthenium complexes on ligand-modified surfaces

    International Nuclear Information System (INIS)

    Yesildag, Ali; Ekinci, Duygu

    2010-01-01

    In this study, pyridine, quinoline and phenanthroline molecules were covalently bonded to glassy carbon (GC) electrode surfaces for the first time using the diazonium modification method. Then, the complexation ability of the modified films with ruthenium metal cations was investigated. The derivatization of GC surfaces with heteroaromatic molecules was achieved by electrochemical reduction of the corresponding in situ generated diazonium salts. X-ray photoelectron spectroscopy (XPS) was used to confirm the attachment of heteroaromatic molecules to the GC surfaces and to determine the surface concentration of the films. The barrier properties of the modified GC electrodes were studied in the presence of redox probes such as Fe(CN) 6 3- and Ru(NH 3 ) 6 3+ by cyclic voltammetry. Additionally, the presence of the resulting organometallic films on the surfaces was verified by XPS after the chemical transformation of the characterized ligand films to the ruthenium complex films. The electrochemical behavior of these films in acetonitrile solution was investigated using voltammetric methods, and the surface coverage of the organometallic films was determined from the reversible metal-based Ru(II)/Ru(III) oxidation waves.

  2. Covalent attachment of pyridine-type molecules to glassy carbon surfaces by electrochemical reduction of in situ generated diazonium salts. Formation of ruthenium complexes on ligand-modified surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Yesildag, Ali [Department of Chemistry, Faculty of Sciences, Atatuerk University, 25240 Erzurum (Turkey); Ekinci, Duygu, E-mail: dekin@atauni.edu.t [Department of Chemistry, Faculty of Sciences, Atatuerk University, 25240 Erzurum (Turkey)

    2010-09-30

    In this study, pyridine, quinoline and phenanthroline molecules were covalently bonded to glassy carbon (GC) electrode surfaces for the first time using the diazonium modification method. Then, the complexation ability of the modified films with ruthenium metal cations was investigated. The derivatization of GC surfaces with heteroaromatic molecules was achieved by electrochemical reduction of the corresponding in situ generated diazonium salts. X-ray photoelectron spectroscopy (XPS) was used to confirm the attachment of heteroaromatic molecules to the GC surfaces and to determine the surface concentration of the films. The barrier properties of the modified GC electrodes were studied in the presence of redox probes such as Fe(CN){sub 6}{sup 3-} and Ru(NH{sub 3}){sub 6}{sup 3+} by cyclic voltammetry. Additionally, the presence of the resulting organometallic films on the surfaces was verified by XPS after the chemical transformation of the characterized ligand films to the ruthenium complex films. The electrochemical behavior of these films in acetonitrile solution was investigated using voltammetric methods, and the surface coverage of the organometallic films was determined from the reversible metal-based Ru(II)/Ru(III) oxidation waves.

  3. Sum frequency generation vibrational spectroscopy (SFG-VS) for complex molecular surfaces and interfaces: Spectral lineshape measurement and analysis plus some controversial issues

    Science.gov (United States)

    Wang, Hong-Fei

    2016-12-01

    Sum-frequency generation vibrational spectroscopy (SFG-VS) was first developed in the 1980s and it has been proven a uniquely sensitive and surface/interface selective spectroscopic probe for characterization of the structure, conformation and dynamics of molecular surfaces and interfaces. In recent years, there have been many progresses in the development of methodology and instrumentation in the SFG-VS toolbox that have significantly broadened the application to complex molecular surfaces and interfaces. In this review, after presenting a unified view on the theory and methodology focusing on the SFG-VS spectral lineshape, as well as the new opportunities in SFG-VS applications with such developments, some of the controversial issues that have been puzzling the community are discussed. The aim of this review is to present to the researchers and students interested in molecular surfaces and interfacial sciences up-to-date perspectives complementary to the existing textbooks and reviews on SFG-VS.

  4. Surface modification of coronary artery stent by Ti-O/Ti-N complex film coating prepared with plasma immersion ion implantation and deposition

    International Nuclear Information System (INIS)

    Huang, N.; Leng, Y.X.; Yang, P.

    2006-01-01

    This paper reported the work of surface coating of Ti-O/Ti-N complex films on coronary stents by means of the plasma immersion ion implantation/deposition process. The deformation behavior of the Ti-O/Ti-N coated stainless steel stents was investigated. In vivo investigation of the anticoagulation behavior of Ti-O coated coronary stents was also performed. The results of mechanical characterization of the Ti-O/Ti-N coated stents show that the film has strong binding strength, and to some extent the ability to withstand plastic deformation. The biological response behavior of the coated stent surface was significantly different from the uncoated. The results of implantation of stents into rabbit ventral aorta show no thrombus formation on the surfaces of the Ti-O coated stents, although serious coagulation had occurred on the surfaces of unmodified stents over a period of 4 weeks under conditions with no anticoagulant

  5. Verification steps for the CMS event-builder software

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    The CMS event-builder software is used to assemble event fragments into complete events at 100 kHz. The data originates at the detector front-end electronics, passes through several computers and is transported from the underground to the high-level trigger farm on the surface. I will present the testing and verifications steps a new software version has to pass before it is deployed in production. I will discuss the current practice and possible improvements.

  6. Technology for bolus verification in proton therapy

    Science.gov (United States)

    Shipulin, K. N.; Mytsin, G. V.; Agapov, A. V.

    2015-01-01

    To ensure the conformal depth-dose distribution of a proton beam within a target volume, complex shaped range shifters (so-called boluses), which account for the heterogeneous structure of patient tissue and organs in the beam path, were calculated and manufactured. The precise manufacturing of proton compensators used for patient treatment is a vital step in quality assurance in proton therapy. In this work a software-hardware complex that verifies the quality and precision of bolus manufacturing at the Medico-Technical Complex (MTC) was developed. The boluses consisted of a positioning system with two photoelectric biosensors. We evaluated 20 boluses used in proton therapy of five patients. A total number of 2562 experimental points were measured, of which only two points had values that differed from the calculated value by more than 0.5 mm. The other data points displayed a deviation within ±0.5 mm from the calculated value. The technology for bolus verification developed in this work can be used for the high precision testing of geometrical parameters of proton compensators in radiotherapy.

  7. Evidence of extensive diversity in bacterial adherence mechanisms that exploit unanticipated stainless steel surface structural complexity for biofilm formation.

    Science.gov (United States)

    Davis, Elisabeth M; Li, Dongyang; Shahrooei, Mohammad; Yu, Bin; Muruve, Daniel; Irvin, Randall T

    2013-04-01

    Three protease-resistant bioorganic 304 stainless steel surfaces were created through the reaction of synthetic peptides consisting of the D-enantiomeric isomer (D-K122-4), the retro-inverso D-enantiomeric isomer (RI-K122-4), and a combination of the two peptides (D+RI) of the Pseudomonas aeruginosa PilA receptor binding domain with steel surfaces. The peptides used to produce the new materials differ only in handedness of their three-dimensional structure, but they reacted with the steel to yield materials that differed in their surface electron work function (EWF) while displaying an identical chemical composition and equivalent surface adhesive force properties. These surfaces allowed for an assessment of the relative role of surface EWF in initial biofilm formation. We examined the ability of various bacteria (selected strains of Listeria monocytogenes, L. innocua, Staphylococcus aureus and S. epidermidis) to initiate biofilm formation. The D-K1224 generated surface displayed the lowest EWF (classically associated with greater molecular interactions and more extensive biofilm formation) but was observed to be least effectively colonized by bacteria (>50% decrease in bacterial adherence of all strains). The highest surface EWF with the lowest surface free energy (RI-K122-4 generated) was more extensively colonized by bacteria, with the binding of some strains being equivalent to unmodified steel. The D+RI generated surface was least effective in minimizing biofilm formation, where some strains displayed enhanced bacterial colonization. Fluorescent microscopy revealed that the D and RI peptides displayed similar but clearly different binding patterns, suggesting that the peptides recognized different sites on the steel, and that differential binding of the peptides to the steel surfaces influences the binding of different bacterial strains and species. We have demonstrated that stainless steel surfaces can be easily modified by peptides to generate surfaces with

  8. Ontology Matching with Semantic Verification.

    Science.gov (United States)

    Jean-Mary, Yves R; Shironoshita, E Patrick; Kabuka, Mansur R

    2009-09-01

    ASMOV (Automated Semantic Matching of Ontologies with Verification) is a novel algorithm that uses lexical and structural characteristics of two ontologies to iteratively calculate a similarity measure between them, derives an alignment, and then verifies it to ensure that it does not contain semantic inconsistencies. In this paper, we describe the ASMOV algorithm, and then present experimental results that measure its accuracy using the OAEI 2008 tests, and that evaluate its use with two different thesauri: WordNet, and the Unified Medical Language System (UMLS). These results show the increased accuracy obtained by combining lexical, structural and extensional matchers with semantic verification, and demonstrate the advantage of using a domain-specific thesaurus for the alignment of specialized ontologies.

  9. Ab Initio Calculations of the Electronic Properties of Polypyridine Transition Metal Complexes and Their Adsorption on Metal Surfaces in the Presence of Solvent and Counterions

    DEFF Research Database (Denmark)

    Jónsson, E. Ö.; Thygesen, Kristian Sommer; Ulstrup, Jens

    2011-01-01

    Os(II)/(III) and Co(II)/(III) polypyridine complexes in aqueous solution are robust molecular entities both in freely solute state and adsorbed on Au(111)- and Pt(111)-electrode surfaces. This class of robust coordination chemical compounds have recently been characterized by electrochemical...... of the complexes in the presence of the solvent, are conserved upon adsorption, whereas the structural features of the different oxidation states are completely lost upon adsorption under vacuum conditions. Detailed microscopic insight such as offered by the present study will be important in molecular...

  10. Covalent co-immobilization of heparin/laminin complex that with different concentration ratio on titanium surface for selectively direction of platelets and vascular cells behavior

    International Nuclear Information System (INIS)

    Wang, Jian; Chen, Yuan; Liu, Tao; Wang, Xue; Liu, Yang; Wang, Yuan; Chen, Junying; Huang, Nan

    2014-01-01

    Highlights: • Extracellular matrix inspired surface modification with fibronectin, heparin and VEGF to construct a favorable microenvironment for selectively anticoagulant and promote endothelialization. • Take the advantage of specific intermolecular interaction, the bioactivity of above biomolecules was more efficiently maintained in compared with the common used covalent immobilization method. • Poly-l-lysine was used as a novel interlayer for surface amination, and in comparison, PLL coating was more feasible and the degradation product had no harm to human body. - Abstract: Surface biofunctional modification of coronary artery stent to improve the hemocompatibility and selectively accelerate endothelium regeneration but prevent restenosis have been become a new hotspot. For this, a novel method was developed in this work by co-immobilization of Ln and heparin complex on poly-L-lysine modified Ti surface. Take the advantage of the specific interaction between Ln and heparin, Ln and heparin complexes with different concentration ratios were set up for creating different exposure density of these two types of biomolecules. According to biocompatibility evaluation results, the Hep/Ln complexes modified surface displayed less platelet adhesion and activation. Especially, on L(150)H and L(200)H surface, the AT III binding quantity, APTT value and anti-coagulation property of modified surface were significantly promoted. Furthermore, the adherent density and proliferation activity of ECs and EPCs were positively correlated with Ln concentration. Notably, the proliferation of both ECs and EPCs on L(100)H, L(150)H and L(200)H surface were greatly promoted. Another hand, the proliferation activity of SMCs was significantly inhibited on Hep/Ln modified surfaces, which was considered mainly due to the inhibitory effect of heparin to SMCs. According to the existing results, this study demonstrated that in a certain range of heparin and laminin concentration ratio

  11. Structure of DNA-Cationic Surfactant Complexes at Hydrophobically Modified and Hydrophilic Silica Surfaces as Revealed by Neutron Reflectometry

    DEFF Research Database (Denmark)

    Cardenas Gomez, Marite; Wacklin, Hanna; Campbell, Richard A.

    2011-01-01

    with dodecyltrimethylammonium bromide (DTAB) and hexadecyltrimethylammonium bromide (CTAB) on hydrophobic surfaces, where we show that DNA molecules are located on top of a self-assembled surfactant monolayer, with the thickness of the DNA layer and the surfactant DNA ratio determined by the surface coverage of the underlying...... interfacial structures, a higher concentration in relation to its cmc is required for the more soluble DTAB surfactant with a shorter alkyl chain than for CTAB. Our results suggest that the DNA Molecules Will spontaneously form a relatively dense, thin layer on top of a surfactant monolayer (hydrophobic...... surface) or a layer of admicelles (hydrophilic surface) as long as the surface concentration of surfactant is great enough to ensure a high interfacial-charge density. These findings have implications for bioanalytical and nanotechnology applications, which require the deposition of DNA layers with well...

  12. Assessment of Land Surface Complexity In Relation To Information Capacity and the Fractal Dimension in Different Landform Regions Using Landsat Data

    International Nuclear Information System (INIS)

    Hong, Wang Xu; Huijie, Qin; Zhe, Zhang; Fei, Li

    2014-01-01

    Remote sensing images are highly structured, and contiguous pixels of space domain have strong correlations that contain abundant information on land surface structure features and land surface electromagnetic radiation features. The information capacity model, which is a quality evaluation model based on a multi-dimensional histogram, includes local correlations within different pixels. Thus, the information capacity can illustrate land surface structural information more objectively and effectively than other single-pixel calculation models. Our results reveal that the information capacity value correlates well with the meaningful grey level of remote sensing imagery. This high correlation is related to the complexity of terrestrial surface landscapes. Therefore, information capacity, as applied to geoscience, is introduced in this study to demonstrate the spatial differentiation of information capacity of different landform regions. Generally, the information capacity of a mountain is large and is followed in decreasing order by those of the hills and the plains. Moreover, the correlation between information capacity and the fractal dimension is analysed. Based on the results of this study, it can be concluded that the level of correlation for information capacity and the fractal dimension is high, and the correlation coefficient for the basic landform areas and the loess landform areas is 0.874 and 0.825, respectively. Finally, this paper proposes that information capacity be used as a new reference index for geoscientific analysis in quantitative research on the characteristics of land surface complexity

  13. Nuclear Data Verification and Standardization

    Energy Technology Data Exchange (ETDEWEB)

    Karam, Lisa R.; Arif, Muhammad; Thompson, Alan K.

    2011-10-01

    The objective of this interagency program is to provide accurate neutron interaction verification and standardization data for the U.S. Department of Energy Division of Nuclear Physics programs which include astrophysics, radioactive beam studies, and heavy-ion reactions. The measurements made in this program are also useful to other programs that indirectly use the unique properties of the neutron for diagnostic and analytical purposes. These include homeland security, personnel health and safety, nuclear waste disposal, treaty verification, national defense, and nuclear based energy production. The work includes the verification of reference standard cross sections and related neutron data employing the unique facilities and capabilities at NIST and other laboratories as required; leadership and participation in international intercomparisons and collaborations; and the preservation of standard reference deposits. An essential element of the program is critical evaluation of neutron interaction data standards including international coordinations. Data testing of critical data for important applications is included. The program is jointly supported by the Department of Energy and the National Institute of Standards and Technology.

  14. Investigation of the Effect of Small Hardening Spots Created on the Sample Surface by Laser Complex with Solid-State Laser

    Science.gov (United States)

    Nozdrina, O.; Zykov, I.; Melnikov, A.; Tsipilev, V.; Turanov, S.

    2018-03-01

    This paper describes the results of an investigation of the effect of small hardening spots (about 1 mm) created on the surface of a sample by laser complex with solid-state laser. The melted area of the steel sample is not exceed 5%. Steel microhardness change in the region subjected to laser treatment is studied. Also there is a graph of the deformation of samples dependence on the tension. As a result, the yield plateau and plastic properties changes were detected. The flow line was tracked in the series of speckle photographs. As a result we can see how mm surface inhomogeneity can influence on the deformation and strength properties of steel.

  15. Impact of terminal cleaning and disinfection on isolation of Acinetobacter baumannii complex from inanimate surfaces of hospital rooms by quantitative and qualitative methods.

    Science.gov (United States)

    Manian, Farrin A; Griesnauer, Sandra; Senkel, Diane

    2013-04-01

    Quantitative broth cultures were obtained from hospital rooms newly vacated by patients positive for multidrug-resistant Acinetobacter baumannii complex (ABC) before and after terminal cleaning and disinfection. Of 10 ABC-positive precleaned room surfaces, 6 (60%) remained culture-positive after terminal cleaning and disinfection. Of a total of 16 room surfaces with detectable ABC by the quantitative method, 5 (31.2%; 95% confidence interval, 13.9%-55.8%) were also culture-positive by the qualitative technique. Copyright © 2013 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

  16. Remarkable fluorescence enhancement versus complex formation of cationic porphyrins on the surface of ZnO nanoparticles

    KAUST Repository

    Aly, Shawkat Mohammede; Eita, Mohamed Samir; Khan, Jafar Iqbal; Alarousu, Erkki; Mohammed, Omar F.

    2014-01-01

    the first experimental measurements demonstrating a clear transition from pronounced fluorescence enhancement to charge transfer (CT) complex formation by simply changing the nature and location of the positive charge of the meso substituent of the cationic

  17. Multifunctional ultra-high vacuum apparatus for studies of the interactions of chemical warfare agents on complex surfaces

    International Nuclear Information System (INIS)

    Wilmsmeyer, Amanda R.; Morris, John R.; Gordon, Wesley O.; Mantooth, Brent A.; Lalain, Teri A.; Davis, Erin Durke

    2014-01-01

    A fundamental understanding of the surface chemistry of chemical warfare agents is needed to fully predict the interaction of these toxic molecules with militarily relevant materials, catalysts, and environmental surfaces. For example, rules for predicting the surface chemistry of agents can be applied to the creation of next generation decontaminants, reactive coatings, and protective materials for the warfighter. Here, we describe a multifunctional ultra-high vacuum instrument for conducting comprehensive studies of the adsorption, desorption, and surface chemistry of chemical warfare agents on model and militarily relevant surfaces. The system applies reflection-absorption infrared spectroscopy, x-ray photoelectron spectroscopy, and mass spectrometry to study adsorption and surface reactions of chemical warfare agents. Several novel components have been developed to address the unique safety and sample exposure challenges that accompany the research of these toxic, often very low vapor pressure, compounds. While results of vacuum-based surface science techniques may not necessarily translate directly to environmental processes, learning about the fundamental chemistry will begin to inform scientists about the critical aspects that impact real-world applications

  18. Multifunctional ultra-high vacuum apparatus for studies of the interactions of chemical warfare agents on complex surfaces.

    Science.gov (United States)

    Wilmsmeyer, Amanda R; Gordon, Wesley O; Davis, Erin Durke; Mantooth, Brent A; Lalain, Teri A; Morris, John R

    2014-01-01

    A fundamental understanding of the surface chemistry of chemical warfare agents is needed to fully predict the interaction of these toxic molecules with militarily relevant materials, catalysts, and environmental surfaces. For example, rules for predicting the surface chemistry of agents can be applied to the creation of next generation decontaminants, reactive coatings, and protective materials for the warfighter. Here, we describe a multifunctional ultra-high vacuum instrument for conducting comprehensive studies of the adsorption, desorption, and surface chemistry of chemical warfare agents on model and militarily relevant surfaces. The system applies reflection-absorption infrared spectroscopy, x-ray photoelectron spectroscopy, and mass spectrometry to study adsorption and surface reactions of chemical warfare agents. Several novel components have been developed to address the unique safety and sample exposure challenges that accompany the research of these toxic, often very low vapor pressure, compounds. While results of vacuum-based surface science techniques may not necessarily translate directly to environmental processes, learning about the fundamental chemistry will begin to inform scientists about the critical aspects that impact real-world applications.

  19. Multifunctional ultra-high vacuum apparatus for studies of the interactions of chemical warfare agents on complex surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Wilmsmeyer, Amanda R.; Morris, John R. [Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061 (United States); Gordon, Wesley O.; Mantooth, Brent A.; Lalain, Teri A. [Research and Technology Directorate, U.S. Army Edgewood Chemical Biological Center, Aberdeen Proving Ground, Maryland 21010 (United States); Davis, Erin Durke [OptiMetrics, Inc., Abingdon, Maryland 21009 (United States)

    2014-01-15

    A fundamental understanding of the surface chemistry of chemical warfare agents is needed to fully predict the interaction of these toxic molecules with militarily relevant materials, catalysts, and environmental surfaces. For example, rules for predicting the surface chemistry of agents can be applied to the creation of next generation decontaminants, reactive coatings, and protective materials for the warfighter. Here, we describe a multifunctional ultra-high vacuum instrument for conducting comprehensive studies of the adsorption, desorption, and surface chemistry of chemical warfare agents on model and militarily relevant surfaces. The system applies reflection-absorption infrared spectroscopy, x-ray photoelectron spectroscopy, and mass spectrometry to study adsorption and surface reactions of chemical warfare agents. Several novel components have been developed to address the unique safety and sample exposure challenges that accompany the research of these toxic, often very low vapor pressure, compounds. While results of vacuum-based surface science techniques may not necessarily translate directly to environmental processes, learning about the fundamental chemistry will begin to inform scientists about the critical aspects that impact real-world applications.

  20. Design verification for reactor head replacement

    International Nuclear Information System (INIS)

    Dwivedy, K.K.; Whitt, M.S.; Lee, R.

    2005-01-01

    This paper outlines the challenges of design verification for reactor head replacement for PWR plants and the program for qualification from the prospective of the utility design engineering group. This paper is based on the experience with the design confirmation of four reactor head replacements for two plants, and their interfacing components, parts, appurtenances, and support structures. The reactor head replacement falls under the jurisdiction of the applicable edition of the ASME Section XI code, with particular reference to repair/replacement activities. Under any repair/replacement activities, demands may be encountered in the development of program and plan for replacement due to the vintage of the original design/construction Code and the design reports governing the component qualifications. Because of the obvious importance of the reactor vessel, these challenges take on an added significance. Additional complexities are introduced to the project, when the replacement components are fabricated by vendors different from the original vendor. Specific attention is needed with respect to compatibility with the original design and construction of the part and interfacing components. The program for reactor head replacement requires evaluation of welding procedures, applicable examination, test, and acceptance criteria for material, welds, and the components. Also, the design needs to take into consideration the life of the replacement components with respect to the extended period of operation of the plant after license renewal and other plant improvements. Thus, the verification of acceptability of reactor head replacement provides challenges for development and maintenance of a program and plan, design specification, design report, manufacturer's data report and material certification, and a report of reconciliation. The technical need may also be compounded by other challenges such as widely scattered global activities and organizational barriers, which

  1. Container Verification Using Optically Stimulated Luminescence

    International Nuclear Information System (INIS)

    Tanner, Jennifer E.; Miller, Steven D.; Conrady, Matthew M.; Simmons, Kevin L.; Tinker, Michael R.

    2008-01-01

    Containment verification is a high priority for safeguards containment and surveillance. Nuclear material containers, safeguards equipment cabinets, camera housings, and detector cable conduit are all vulnerable to tampering. Even with a high security seal on a lid or door, custom-built hinges and interfaces, and special colors and types of finishes, the surfaces of enclosures can be tampered with and any penetrations repaired and covered over. With today's technology, these repairs would not be detected during a simple visual inspection. Several suggested solutions have been to develop complicated networks of wires, fiber-optic cables, lasers or other sensors that line the inside of a container and alarm when the network is disturbed. This results in an active system with real time evidence of tampering but is probably not practical for most safeguards applications. A more practical solution would be to use a passive approach where an additional security feature was added to surfaces which would consist of a special coating or paint applied to the container or enclosure. One type of coating would incorporate optically stimulated luminescent (OSL) material. OSL materials are phosphors that luminesce in proportion to the ionizing radiation dose when stimulated with the appropriate optical wavelengths. The OSL fluoresces at a very specific wavelength when illuminated at another, very specific wavelength. The presence of the pre-irradiated OSL material in the coating is confirmed using a device that interrogates the surface of the enclosure using the appropriate optical wavelength and then reads the resulting luminescence. The presence of the OSL indicates that the integrity of the surface is intact. The coating itself could be transparent which would allow the appearance of the container to remain unchanged or the OSL material could be incorporated into certain paints or epoxies used on various types of containers. The coating could be applied during manufacturing

  2. A surface complexation model of YREE sorption on Ulva lactuca in 0.05-5.0 M NaCl solutions

    Science.gov (United States)

    Zoll, Alison M.; Schijf, Johan

    2012-11-01

    We present distribution coefficients, log iKS, for the sorption of yttrium and the rare earth elements (YREEs) on BCR-279, a dehydrated tissue homogenate of a marine macroalga, Ulva lactuca, resembling materials featured in chemical engineering studies aimed at designing renewable biosorbents. Sorption experiments were conducted in NaCl solutions of different ionic strength (0.05, 0.5, and 5.0 M) at T = 25 °C over the pH range 2.7-8.5. Distribution coefficients based on separation of the dissolved and particulate phase by conventional filtration (3 kDa) using an existing pH-dependent model. Colloid-corrected values were renormalized to free-cation concentrations by accounting for YREE hydrolysis and chloride complexation. At each ionic strength, the pH dependence of the renormalized values is accurately described with a non-electrostatic surface complexation model (SCM) that incorporates YREE binding to three monoprotic functional groups, previously characterized by alkalimetric titration, as well as binding of YREE-hydroxide complexes (MOH2+) to the least acidic one (pKa ∼ 9.5). In non-linear regressions of the distribution coefficients as a function of pH, each pKa was fixed at its reported value, while stability constants of the four YREE surface complexes were used as adjustable parameters. Data for a single fresh U. lactuca specimen in 0.5 M NaCl show generally the same pH-dependent behavior but a lower degree of sorption and were excluded from the regressions. Good linear free-energy relations (LFERs) between stability constants of the YREE-acetate and YREE-hydroxide solution complex and surface complexes with the first and third functional group, respectively, support their prior tentative identifications as carboxyl and phenol. A similar confirmation for the second group is precluded by insufficient knowledge of the stability of YREE-phosphate complexes and a perceived lack of YREE binding in 0.05 M NaCl; this issue awaits further study. The results

  3. Adhesion and cleaning of foods with complex structure: Effect of oil content and fluoropolymer coating characteristics on the detachment of cake from baking surfaces

    OpenAIRE

    Magens, Ole; Liu, Y; Hofmans, JFA; Nelissen, JA; Wilson, David Ian

    2017-01-01

    The effect of surface coating on the detachment of a complex microstructured food material, was investigated using an improved version of the millimanipulation device described by Ali et al. (2015 $\\textit{Food & Bioproducts Processing}$, Vol. 93, 256–268). The test material was baked sponge cake batter, which contains approximately 27 vol% bubbles in a ‘continuous’ phase of emulsified oil in a flour/syrup suspension. Detachment in the dry state was studied for aluminium, 304 stainless steel ...

  4. How to Find a Bug in Ten Thousand Lines Transport Solver? Outline of Experiences from AN Advection-Diffusion Code Verification

    Science.gov (United States)

    Zamani, K.; Bombardelli, F.

    2011-12-01

    Almost all natural phenomena on Earth are highly nonlinear. Even simplifications to the equations describing nature usually end up being nonlinear partial differential equations. Transport (ADR) equation is a pivotal equation in atmospheric sciences and water quality. This nonlinear equation needs to be solved numerically for practical purposes so academicians and engineers thoroughly rely on the assistance of numerical codes. Thus, numerical codes require verification before they are utilized for multiple applications in science and engineering. Model verification is a mathematical procedure whereby a numerical code is checked to assure the governing equation is properly solved as it is described in the design document. CFD verification is not a straightforward and well-defined course. Only a complete test suite can uncover all the limitations and bugs. Results are needed to be assessed to make a distinction between bug-induced-defect and innate limitation of a numerical scheme. As Roache (2009) said, numerical verification is a state-of-the-art procedure. Sometimes novel tricks work out. This study conveys the synopsis of the experiences we gained during a comprehensive verification process which was done for a transport solver. A test suite was designed including unit tests and algorithmic tests. Tests were layered in complexity in several dimensions from simple to complex. Acceptance criteria defined for the desirable capabilities of the transport code such as order of accuracy, mass conservation, handling stiff source term, spurious oscillation, and initial shape preservation. At the begining, mesh convergence study which is the main craft of the verification is performed. To that end, analytical solution of ADR equation gathered. Also a new solution was derived. In the more general cases, lack of analytical solution could be overcome through Richardson Extrapolation and Manufactured Solution. Then, two bugs which were concealed during the mesh convergence

  5. Slope of the Slope Derivative Surface used to characterize the complexity of the seafloor around St. John, USVI

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Slope of slope was calculated from the bathymetry surface for each raster cell by applying the ArcGIS Spatial Analyst 'Slope' Tool to a previously created slope...

  6. Molecular Studies of Complex Soil Organic Matter Interactions with Metal Ions and Mineral Surfaces using Classical Molecular Dynamics and Quantum Chemistry Methods

    Science.gov (United States)

    Andersen, A.; Govind, N.; Laskin, A.

    2017-12-01

    Mineral surfaces have been implicated as potential protectors of soil organic matter (SOM) against decomposition and ultimate mineralization to small molecules which can provide nutrients for plants and soil microbes and can also contribute to the Earth's elemental cycles. SOM is a complex mixture of organic molecules of biological origin at varying degrees of decomposition and can, itself, self-assemble in such a way as to expose some biomolecule types to biotic and abiotic attack while protecting other biomolecule types. The organization of SOM and SOM with mineral surfaces and solvated metal ions is driven by an interplay of van der Waals and electrostatic interactions leading to partitioning of hydrophilic (e.g. sugars) and hydrophobic (e.g., lipids) SOM components that can be bridged with amphiphilic molecules (e.g., proteins). Classical molecular dynamics simulations can shed light on assemblies of organic molecules alone or complexation with mineral surfaces. The role of chemical reactions is also an important consideration in potential chemical changes of the organic species such as oxidation/reduction, degradation, chemisorption to mineral surfaces, and complexation with solvated metal ions to form organometallic systems. For the study of chemical reactivity, quantum chemistry methods can be employed and combined with structural insight provided by classical MD simulations. Moreover, quantum chemistry can also simulate spectroscopic signatures based on chemical structure and is a valuable tool in interpreting spectra from, notably, x-ray absorption spectroscopy (XAS). In this presentation, we will discuss our classical MD and quantum chemistry findings on a model SOM system interacting with mineral