Добірка наукової літератури з теми "Reaction path finding"

In recent times, autonomous robots have become more relevant, aiming not only to be an extension of mobility and human performance but also allowing them to independently solve specific problems such as finding free-collision paths within some defined environments. In order to achieve this, several techniques have been developed, like action-reaction algorithms, sampling-based algorithms, and deterministic algorithms such as the Homotopy Path Planning Method (HPPM). This work presents, for the first time, a complete deterministic collision-free path planning scheme implemented in FPGA, which is mounted on a Scribbler 2 robot from Parallax. Then, an automatic algorithm of the repulsion parameter for the HPPM method is presented, using as a reference the minimum distance between the center of each obstacle with respect to the homotopic ideal path; furthermore, an algorithm is proposed for discriminating dead-end routes and collision risk trajectories, which allows us to obtain a feasible free-collision path that takes into account the robot dimensions. Besides, comparative performance tests have been carried out against other path-finding methods from the low degrees of freedom (low DoF) and sampling-based planners. Our proposal exhibits path calculation times which are 5 to 10 times faster on FPGA implementation, compared to the other methods and 10 to 100 times faster on PC implementation also compared to the rest. Similar results are obtained with regards to memory consumption, namely 20 to 200 times lower on FPGA implementation and 10 to 100 times lower on PC implementation.

Analysis of the fragmentation pathways of molecules in mass spectrometry gives a fundamental insight into gas-phase ion chemistry. However, the conventional intrinsic reaction coordinates method requires knowledge of the transition states of ion structures in the fragmentation pathways. Herein, we use the nudged elastic band method, using only the initial and final state ion structures in the fragmentation pathways, and report the advantages and limitations of the method. We found a minimum energy path of p-benzoquinone ion fragmentation with two saddle points and one intermediate structure. The primary energy barrier, which corresponded to the cleavage of the C–C bond adjacent to the CO group, was calculated to be 1.50 eV. An additional energy barrier, which corresponded to the cleavage of the CO group, was calculated to be 0.68 eV. We also found an energy barrier of 3.00 eV, which was the rate determining step of the keto-enol tautomerization in CO elimination from the molecular ion of phenol. The nudged elastic band method allowed the determination of a minimum energy path using only the initial and final state ion structures in the fragmentation pathways, and it provided faster than the conventional intrinsic reaction coordinates method. In addition, this method was found to be effective in the analysis of the charge structures of the molecules during the fragmentation in mass spectrometry.

The reaction path is an important concept of theoretical chemistry. We use a definition with a reduced gradient (see Quapp et al., Theor Chem Acc100:285, 1998), also named Newton trajectory (NT). To follow a reaction path, we design a numerical scheme for a method for finding a transition state between reactant and product on the potential energy surface: the growing string (GS) method. We extend the method (see W. Quapp, J Chem Phys122:174106, 2005) by a second-order scheme for the corrector step, which includes the use of the Hessian matrix. A dramatic performance enhancement for the exactness to follow the NTs, and a dramatic reduction of the number of corrector steps are to report. Hence, we can calculate flows of NTs. The method works in nonredundant internal coordinates. The corresponding metric to work with is curvilinear. The GS calculation is interfaced with the GamessUS package (we have provided this algorithm on ). Examples for applications are the HCN isomerization pathway and NTs for the isomerization C7ax ↔ C5 of alanine dipeptide.

The probability of existence of a stepwise route which is in parallel with the well-known concerted pathway for the mechanism of 1,3-dipolar cycloaddition is debated by many researchers. As the route is stepwise, it would lead to emergence of at least a metastable intermediate which would produce some stereoisomers such as enantiomers and diastereomers. In 1986 the first clear stepwise example for a 1,3-dipolar cycloaddition was reported by Huisgen where an electron-poor alkene was reacted with a thiocarbonyl ylide. Since then, researchers have focused on the thiocarbonyl ylide 1,3-dipolar group in finding more stepwise examples. It was found that some reactions of a thiocarbonyl ylide with some dipolarophiles proceeded by a stepwise route, while others did not. This situation led us to investigate the probability of existence a stepwise route in parallel with the concerted path for the reaction of methyl thiocarbonyl S-oxide and C20 fullerene as a chemically active and nano-dimension electronegative alkene. To give more reliable data, Born–Oppenheimer ab initio QM/MM molecular dynamics was used.

Shallow subsurface flow is a dominant process controlling hillslope runoff generation, soil development, and solute reaction and transport. Despite their importance, the location and geometry of these flow paths are difficult to determine. In arctic environments, shallow subsurface flow paths are limited to a thin zone of seasonal thaw above permafrost, which is traditionally assumed to mimic the surface topography. We have used a combined approach of electrical resistivity tomography (ERT) and self-potential (SP) measurements to map shallow subsurface flow paths in and around water tracks, drainage features common to arctic hillslopes. ERT measurements delineate thawed zones in the subsurface that control flow paths, whereas SP is sensitive to groundwater flow. We have found that areas of low electrical resistivity in the water tracks were deeper than manual thaw depth estimates and varied from the surface topography. This finding suggests that traditional techniques might underestimate active-layer thaw and the extent of the flow path network on arctic hillslopes. SP measurements identify complex 3D flow paths in the thawed zone. Our results lay the groundwork for investigations into the seasonal dynamics, hydrologic connectivity, and climate sensitivity of spatially distributed flow path networks on arctic hillslopes.

This paper presents the results of computer simulation of tautomeric transformations of the molecule 1-amino-4-phenylamino-9,10-anthraquinone. It is known from the literature that the presence of substituents in the 1,4-position of anthraquinone-9,10 leads to various tautomeric transformations, with a shift in the absorption maximum and the appearance of absorption bands in the red wave region in electronic spectra. Both the 1-amino-4-hydroxyanthraquinone described in the literature and the 1-amino-4-phenylamino-9,10-anthraquinone are characterized by two types of prototropic tautomerism – keto-enol and amino-imine. Quantum-chemical modeling contributes to the calculation of the relative energies of tautomers and isomers, the barriers of their interconversions, as well as finding their structural parameters. The aim of this study was to study the mechanism of the formation of tautomers during hydrogen transfer in the molecule of 1-amino-4-phenylamino-9,10-anthraquinone, as well as the formation of isomers during migration of the OH group. The calculations were performed using the Gaussian09 program. To study of various tautomers of 1-amino-4-phenylamino-9,10-anthraquinone, the B3LYP method with the def2TZV basis was used. A search was conducted for transition states during hydrogen transfer and OH group migration. The descent along the reaction path was calculated to confirm that the transition state is in the path of the desired reaction. The minima corresponding to the starting material and product were localized. The activation enthalpies of the studied reactions were calculated. Migration of the OH group in the 1-amino-4-phenylamino-9,10-anthraquinone molecule leads to the formation of 4-phenylamino-9-amino-1,10-anthraquinone. As the calculation shows, the keto-form of 1-amino-4-phenylamino-9,10-anthraquinone is energetically more profitable than all the isomers studied in this work, including the enol form. The smallest difference in total potential energies is 23.7 kJ/mol between the initial ketone form of 1-amino-4-phenylamino-9,10-anthraquinone and the last transformation structure – the 4-phenylamino-9-amino-1,10-anthraquinone molecule.

Les caractéristiques d'une réaction chimique sont largement déterminées par les structures moléculaires associées au réactif, au produit, à l'état de transition et au chemin qui les relie. Par conséquent, localiser les points stationnaires sur la surface du potentiel moléculaire est la première étape vers une modélisation numérique réussie. Mathématiquement, les réactifs, les produits et les intermédiaires réactifs sont des minima locaux sur la surface d'énergie potentielle. Deux minima locaux sont reliés par un point stationnaire qui est un maximum le long du chemin de réaction mais un minimum dans toutes les autres directions. Ce point de selle est appelé l'état de transition (TS) entre les deux minima locaux. Une fois que tous les points stationnaires importants sur la surface du potentiel ont été localisés, on peut modéliser l'ensemble du processus de réaction, y compris le (s) mécanisme (s) de la réaction et ses propriétés cinétiques et thermodynamiques (vitesse de réaction, constante d'équilibre, exothermicité, etc. réactions en plusieurs étapes, l'existence d'intermédiaire (s) complique le mécanisme de réaction. De plus, il peut y avoir plusieurs chemins de réaction possibles, dans lesquels différentes structures intermédiaires relient les mêmes réactifs et produits. Dans ces scénarios compliqués, avoir un chemin complet d'énergie minimale montrant La manière dont les réactifs et les produits sont reliés par diverses séquences de structures est particulièrement utile, car elle fournit aux chercheurs des détails atomistiques sur le mécanisme de réaction. Cela peut être utile, par exemple, pour concevoir de meilleurs catalyseurs. [...]
The characteristics of a chemical reaction are largely determined by the molecular structures associated with the reactant, the product, the transition state, and the path connecting them. Therefore, locating the stationary points on the molecular potential surface is the first step towards successful numerical modeling. Mathematically, reactants, products, and reactive intermediates are local minima on the potential energy surface. Two local minima are connected by a stationary point which is a maximum along the reaction path but a minimum in all other directions. This saddle point is called the transition state (TS) between the two local minima. Once all the important stationary points on the potential surface have been located, one can model the whole reaction process, including the mechanism(s) of the reaction and its kinetic and thermodynamic properties (reaction rate, equilibrium constant, exothermicity, etc.. For multistep reactions, the existence of intermediate(s) complicates the reaction mechanism. In addition, there may be multiple possible reaction paths, wherein different intermediate structures connect the same reactants and products. In these complicated scenarios, having a full minimum-energy path showing how reactants and products are connected by various sequences of structures is especially useful, as it provides researchers with atomistic detail about the reaction mechanism. This can be useful, for example, for designing better catalysts. [...]

Access to public restrooms and transgender people serving openly in the U.S. military are the two most visible public issues related to transgender rights in recent American history. This chapter describes several randomized public opinion experiments testing how to increase public support for those policies. One experiment finds that framing transgender bathroom access as about freedom or safety does little to increase support for transgender bathroom access rights; although consistent with opposition advertising campaigns, those frames can generate significant decreases in support. Elite cues and framing of the military service issue as about equality and integrity show more promise in increasing support for transgender rights. The studies in this chapter serve as the core of Identity Reassurance Theory and its central tenets about bolstering self-esteem and finding the optimal messaging strategy to mitigate emotional reactions.

We describe a model-based construction of an online tester for black-box testing. Contemporary model-based online test generators focusing mainly on computationally cheap but far from optimal planning strategies cover just a fraction of the wide spectrum of test control strategies. Typical examples of those used are simple random choice and anti-ant. Exhaustive planning during online testing of nondeterministic systems looks out of reach because of the low scalability of the methods in regard to the model size. The reactive planning tester (RPT) studied in this chapter is targeted to fill the gap between these two extremes. The key idea of RPT lies in offline static analysis of the IUT (implementation under test) model to prepare the data and constraints for efficient online reactive planning. The external behavior of the IUT is modelled as an output observable nondeterministic EFSM (extended finite state machine) with the assumption that all the transition paths are feasible. A test purpose is attributed to the transitions of the IUT model by a set of Boolean variables called traps that are used to measure the progress of the test run. We present a way to construct a tester that at runtime selects a suboptimal test path from trap to trap by finding the shortest path that covers unvisited traps within planning horizon. The principles of reactive planning are implemented in the form of the decision rules of selecting the shortest paths at runtime. Based on an industrial scale case study, namely the city lighting system controller, we demonstrate the practical use of the RPT for systems with high degree of nondeterminism, deep nested control loops, and requiring strictly bounded tester response time. Tuning the planning horizon of the RPT allows a trade-off to be found between close to optimal test length and scalability of tester behavior with computationally feasible expenses.

Odors affect various physiological and mental activities. Previous studies in rats have shown that the odors of grapefruit and Osmanthus fragrans (OSM, fragrant tea olive) attenuate food intake, leading to a reduction in body weight gain, but it is not yet clear whether the causative mechanisms underlying these effects are the same for both odors. The first part of the present study revealed that grapefruit odor had no effect on the expression of feeding-related neuropeptides, in contrast to the previous finding that OSM odor suppresses orexigenic and activates anorexigenic neuropeptides in the hypothalamus of the rat. The second part revealed that OSM odor activated the parasympathetic nerve, in contrast to the previous finding demonstrating that grapefruit odor activates sympathetic nerve activity. The third part was performed to confirm the previous findings about the effects of OSM odor on appetitive reactions in humans. In human subjects, we found that continuous exposure to OSM odor attenuated appetite and consumption of snacks (cookies) and improved mood, when evaluated using the POMS (Profile of Mood States) data from university students. In conclusion, OSM odor attenuated appetite and decreased food intake in humans, and the underlying causative mechanisms differed from those mediating the effects of grapefruit odor, specifically in terms of the expression of hypothalamic feeding-related neuropeptides and autonomic nerve activity.

In analysing attitudes and perceptions of people and political party proposals, and how we can lay the bases for searching the explanations of characteristics and level of implementation of our two values, first, we recall one of the key findings discussed in this chapter: the changes, the levels, the characteristics of the demand and elite supply of the two values are highly context- and time-dependent. Citizens’ demands and party supply are dependent on the historical trajectory and the economic situation. This partial finding shows that in the middle and long run there is a steady consistency between people’s attitudes and leader actions, on the one hand, and social, economic, cultural reality, on the other. Consequently, the requests for equality and freedom are consistent with the existing socio-economic-cultural reality. A second remark is a difference in terms of volatility/resilience between attitudes and realities. The demand and party supply of equality and freedom can be more or less volatile as reactions to the changes and uncertainties brought about by the economic situation, or other factors, such as technological changes, industrial organization developments, working conditions changes, economic mobility and the whole existing structure of external opportunities. Finally, up to now, the empirical evidence suggests that the demand for implementation of the two values seems to follow different logic and different paths. What this discussion and the related findings are pointing to is also the responsiveness seen from a more realistic perspective.

Abstract Carbon dioxide capture, utilization, and storage (CCUS), which includes conversion to valuable products, is a complex modern issue with many perspectives. In recent years, the idea of using carbon dioxide (CO2) as a feedstock for synthetic applications in the chemical and fuel sectors via reduction reactions has piqued interest. If the hydrogen is created using a renewable energy source, catalytic CO2 hydrogenation is the most viable and appealing alternative among the existing CO2-recycling solutions. CO2 hydrogenation has many chemical paths depending on the catalyst, and multiple value-added hydrocarbons can be generated. This research looks into a catalyst development for converting high CO2 gas field into methane and alcohols. The study focused on catalytic conversion of CO2 to methane over Ru based catalyst while in the case of alcohols using Cu based catalyst. Both catalysts were synthesized via impregnation techniques where the aqueous precursors’ solution were impregnated on the oxide supports, stirred, filtered and washed. The samples were then dried, ground and calcined. The synthesized catalysts were characterized using various analytical techniques (e.g., TPR, FESEM, N2 adsorption-desorption, XRD) for their physicochemical properties. The catalytic performance in CO2 hydrogenation was performed using a fixed bed reactor at various factors such as temperature, pressure, feed gas ratio and space velocity. The experimental findings indicate that conversion of CO2 to methane over Ru based catalyst resulted in >84% CO2 conversion with 99% methane selectivity in the range of temperature 280 – 320 °C and at atmospheric pressure. In the case of hydrogenation of CO2 to alcohols, the catalytic performance of Cu based catalyst exhibited CO2 conversion of >11% and selectivity towards alcohols, C1 and C2, both at 4% with reaction temperature of 250 °C and pressure 30 bar. These findings revealed that methane could easily be formed from CO2 as compared to alcohol. However, both technology conversions are dependent on the catalyst selection and its’ activity. Process parameters need to be optimized to maximize targeted product formation and suppress the side products.

Research activities on the combustion of synthetic jet fuels and bio-derived jet fuels have increased notably over the last 10 years in order to solve the challenging reduction of dependence of air transportation on petroleum. Within the European Community’s Seventh Framework Programme, the combustion of a 100% GtL from Shell and a 80/20% vol. GtL/1-hexanol blend were studied in a jet-stirred reactor (JSR). This synthetic GtL fuel mainly contains n-alkanes, iso-alkanes, and cyclo-alkanes. We studied the oxidation of these alternatives jet fuels under the same conditions (temperature, 550–1150 K; pressure, 10 bar; equivalence ratio, 0.5–2; initial fuel concentration, 1000 ppm). For simulating the oxidation kinetics of these fuels we used a new surrogate mixture consisting of n-dodecane, 3-methylheptane, n-propylcyclohexane, and 1-hexanol. A detailed chemical kinetic reaction mechanism was developed and validated by comparison with the experimental results obtained in a jet-stirred reactor. The current model was also tested for the autoignition of the GtL fuel under shock tubes conditions (φ = 1 and P = 20 atm) using data from the literature. Kinetic computations involving reaction paths analyses and sensitivity analyses were used to interpret the results. The general findings are that the GTL and GTL/hexanol blend have very similar reactivity to Jet A-1, which is important since GTL is a drop-in fuel that should have similar performance to the Jet A-1 baseline and 1-hexanol should not significantly affect the reactivity if it is to be used as an additive.

An industrial axial compressor has to meet a wide range of operation requirements. These machines have to run continuously for four to five years before going for overhaul. Hence, overall high level of efficiency may be slightly relaxed to meet this requirement. This requires axial flow compressor design to be more conservative and flexible to accommodate changes required for process industry through modern design & development approaches. This paper deals with finding of optimum flow path configuration that will allow a successful detailed design to follow. The effect of various parameters such as hub to tip ratio, proper selection of design rpm, reactions, work coefficient & flow coefficient has been investigated and selected for optimal performance of the machine. Last stage of the compressor is selected as radial stage with the advantage of reduction in axial length and to provide radial outlet, which is more suitable outlet configuration. Meanline design and streamline analysis for each configuration is determined to find out good operating range (stall-free operation) before starting the detailed design.

In this paper, characteristics of turbulent combustion and NOx emission for high hydrogen-content fuel gases (H2 > 70 vol. %; “hydrogen-rich”) are addressed. An experimental investigation is performed in a perfectly-premixed axial-dump combustor under gas turbine relevant conditions. Fundamental features of turbulent combustion for these mixtures are evaluated based on OH-PLIF diagnostics. On the other hand, NOx emissions are measured with an exhaust gas sampling probe positioned downstream the combustor outlet. Compared to syngas mixtures (H2 + CO), the operational limits for hydrogen-rich fuel gases are found to occur at even leaner conditions concerning flashback phenomena. With respect to effects of operating pressure, a strongly reduced operational envelope is observed at elevated pressure. Only with decreasing the preheat temperature a viable approach to further extend the operational range is seen. Evaluation of the averaged turbulent flame shape shows that the profile of the flame front is generally approaching that of an ideal cone. Thus a simplified approach for estimating the turbulent flame speed via the location of the flame tip alone can be applied. The level of NOx emission for the hydrogen-rich fuel mixtures is generally above that of syngas mixtures, which exhibit already higher NOx emission values than natural gas. Distinct chemical kinetic features are found specifically at elevated pressure. While the pressure effects are weak for syngas, a non-monotonic behavior is observed for the hydrogen-rich fuels. Reaction path analysis is performed to complement and provide more insight to the findings from the measurements. From chemical kinetic calculations a distinct shift in NOx formation pathways (thermal NOx vs. NOx through N2O/NNH reaction channels) can be observed for the different fuel mixtures at different pressure levels.

Educational trails are a traditional tool to bring local attractions closer to the visitor of the area. However, educational trails are currently changing concepts. The classic model of whiteboards with text and images no longer works - visitors do not want to read long texts. They require interactivity and a sophisticated visual experience. With the development of modern communication technologies, there is an opportunity to meet these expectations by connecting educational content with a virtual environment. The article aims to present several different types of virtual nature trails in Czechia and assess the strengths and weaknesses of their implementation from visitors' perspective. The input data are data from evaluation questionnaires from guided excursions, a substantial part of which were these educational trails; the method used is content analysis. The main findings include that visitors accept these new forms of nature trails mostly positively. Negative reactions were more of a practical nature when something did not work as it should. In addition, creating and maintaining a virtual nature trail can be significantly cheaper than its physical form, which is an advantage in rural regions where local governments do not have large budgets. The author of this article is also a co-author of one of the assessed paths; therefore, practical advice regarding the implementation of virtual educational paths is also discussed.

Abstract Carbon dioxide injection into sedimentary formations has been widely used in enhanced oil recovery (EOR) and geological-storage projects. Several field cases have shown an increase in water injectivity during CO2 Water-Alternating-Gas (WAG) projects. Although there is consensus that the rock-fluid interaction is the main mechanism, modeling this process is still challenging. Our main goal is to validate a physically based model on experimental observations and use the validated model to predict CO2 injectivity alteration based on geochemical reactions in carbonate rocks. In this paper, we present a new method for CO2 reactive transport in porous media and its impact on injectivity. We hypothesize that if CO2 solubilizes in the connate water, then it induces a shift in chemical equilibrium that stimulates mineral dissolution. Consequently, porosity and permeability will increase, and cause alterations to well injectivity. We develop a predictive model to capture this phenomenon and validate the model against available data in the literature. We use UTCOMP-IPhreeqc, which is a fully coupled fluid-flow and geochemical simulator to account for rock/hydrocarbon/water interactions. In addition, we perform several experiments to test CO2/water slug sizes, mineralogy assembly, injected brine composition, and gravity segregation combined with the effect of heterogeneity. Coreflood simulations using chemical equilibrium and kinetics indicate mineral dissolution at reservoir conditions. The results suggest that the intensity of rock dissolution depends on formation mineralogy and brine composition as carbonate systems work as buffers. Additionally, we show that prolonged CO2 and brine injection induces petrophysical alteration close to the injection region. Our field-scale heterogeneous reservoir simulations show that permeability alteration calculated based on Carman-Kozeny correlation and wormhole formulation had the same results. Furthermore, we observed that water injectivity increased by almost 20% during subsequent cycles of CO2-WAG. This finding is also supported by the Pre-Salt carbonate field data available in the literature. In the case of continuous CO2 injection, the carbonate dissolution was considerably less severe in comparison with WAG cases, but injectivity increased due to unfavorable CO2 mobility. With the inclusion of gravity segregation, we report that the injectivity doubles in magnitude. The simulations show more extensive dissolution at the upper layers of the reservoir, suggesting that preferential paths are the main cause of this phenomenon. The ideas presented in this paper can be utilized to improve history-matching of production data and consequently reduce the uncertainty inherent to CO2-EOR and carbon sequestration projects.

In the late 1980s and early 90s, several companies tested a range of acoustic devices for monitoring valve leakage during the check-valve diagnostic system research performed at the Utah State Water Research Laboratory as part of two separate nuclear-industry-sponsored initiatives. The acoustic sensor technology and analysis techniques evaluated were found helpful but no progress was made in non-intrusively quantifying the leak rate through the valves tested during these programs. Around that same time, oil & gas companies in the UK were experimenting with detection and quantification of valve leakage using acoustic emission (AE) technology. The AE sensors and signal-processing technology selected for the UK oil & gas effort responded to much higher frequencies compared to the sensors and systems used during the nuclear-utility initiative in the U.S. This research led to new products for detection and quantification of valve leakage in oil & gas applications. Because of minimum leak threshold and accuracy concerns, non-intrusive acoustic valve leak measurement has remained an elusive goal for commercial nuclear power. Various general-purpose acoustic tools have been trialed to detect leakage with mixed results because of complications caused by plant and system acoustic characteristics. Several of today’s moderately successful check-valve diagnostic systems employ acoustic sensors and can detect the most likely event representing flow cutoff when a check-valve disc fully closes, but leak-rate quantification with any of these systems is not possible. Correlation methods and other AE analysis techniques that have been developed to quantify leakage in steam systems have been generalized as small, medium, and large leakage classifications with no clear criteria for these levels. During the last couple of years, nuclear-plant engineers responsible for programs for compliance with Appendix J, “Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors,” to Part 50, “Domestic Licensing of Production and Utilization Facilities,” of Title 10, “Energy,” of the Code of Federal Regulations (Appendix J to 10 CFR 50) have made extensive use of a new acoustic valve leak-detection system known as MIDAS Meter®. Appendix J valve testing (also known as Type C testing) requires that sections of nuclear-plant piping be isolated by closing a number of valves, thereby creating a confined pressure boundary. The isolated piping within the boundary is pressurized with approximately 344.7 kilopascals (kPa) [50 pounds per square inch (psi)] of air and the leak-tightness of the boundary is evaluated. When the isolated piping exhibits excess leakage or cannot maintain the test pressure, the valves creating the boundary are evaluated one by one to find the culprit leaker. The process of finding and correcting the problem valve can take from hours to several days and may become an outage critical-path activity. Appendix J engineers have enjoyed considerable success with their newfound ability to quickly and confidently identify the leaking valves with MIDAS Meter® and remove their test programs from the critical path. MIDAS Meter® is a high-frequency acoustic-emission-based system which includes algorithms that convert the acoustic emission signal to leak rate. The basic algorithms were first developed from the field results obtained during the early development work for UK oil & gas operators and refined over the next 20 years. Though not originally validated under a quality-assurance (QA) program of the 10 CFR 50 type, nuclear plants that own MIDAS Meter® have been eager to go beyond simple troubleshooting and use the leak quantification results for nuclear applications, including safety-related decisionmaking. In order to support owners and avoid improper application of this very successful new tool, Score Atlanta embarked on an extensive validation program consistent with 10 CFR Part 50 requirements. A purpose-built leak-test flow loop and valve simulator apparatus were constructed in the Atlanta facility and testing began in early 2013. To support Appendix J users, the air testing was performed first and completed in July 2013. The water testing followed and should be completed in early 2014. Numerous combinations of leak path, leak-path geometry, and differential pressure were created and evaluated during the air phase of the program. Pressure was limited to 1034 kPa [150 psi] for air testing. The water testing includes pressures up to 8,618 kPa [1,250 psi] and a similar number of varying leak paths and pressure test points. This paper discusses the preliminary results of the test program, including any special limitations required for use of AE-derived valve leak results in nuclear safety-related applications. The full results of the test program and guidance for nuclear safety-related use of the technology are expected to be available ahead of the 2014 ASME-NRC Valve Symposium. Paper published with permission.

The Functional Failure Identification and Propagation (FFIP) framework has been proposed in prior work to study the reliability of early phase designs of complex systems. For the specified functionality, a model of mechanical, electrical and software components has been defined to support simulation and discovery of fault propagation paths. The advantage of this approach has been the possibility to identify unreliable designs before high cost design commitments have been made. However, a weakness is that the results are specific to the component model that is created for the purpose of running the FFIP simulations; it is unclear how the results would change if different modeling choices would have been made. Further, the usefulness of the method in design has been limited to evaluating reliability rather than actively finding more robust design alternatives. In order to address these weaknesses, the FFIP component model needs to incorporate a capability to describe design alternatives. The feature modeling syntax and semantics, which has been successfully used by software engineers to describe customer variations in product lines, is applied here to specify alternative mechanical, electrical and software features of a cyber-physical system. In the concept phase, all plausible design alternatives are described with a feature model. FFIP analyses can be performed for each valid configuration of this model, and all alternatives that are found unreliable are removed. The result is a restricted feature model, comprising significantly fewer design alternatives, that is delivered as source information for the detailed design phase. A toolchain for performing these analyses is presented, integrating open source feature modeling and configuration tools to the FFIP environment. The methodology is illustrated with a case study from boiling water nuclear reactor design.

Abstract How can a business develop sustainable societal relationships in a world that is often described as volatile, uncertain, complex and ambiguous? While public expectations of companies are complicated and continuously changing, there are clear underlying trends in modern society that shape this relationship. Understanding these trends allows a company to develop the capability of proactively managing societal relationships. The findings of the study are especially relevant for industries that visibly operate in the public space and should anticipate societal resistance. This paper first describes the societal trends that shaped the way people and organizations have interacted since the Second World War. In this period increasing environmental and social awareness and assertiveness developed along three evolutionary paths: –active public discourse that continuously pushes the boundaries of what is deemed acceptable and desirable, with increasing focus on human values and space for the individual;–industry sectors and international organizations that try to preempt new societal expectations with voluntary guidelines and self-regulation; and–governments that formalize important and matured parts of the public discourse and voluntary guidelines in laws and regulations. Secondly, the authors adopt a practical model to describe how companies have struggled to keep up with this continuously evolving and dynamic societal landscape due to lack of adaptation. An increasingly defensive and reactive business approach to societal pressure has led to a low point in trust from stakeholders. To regain trust and their social license to operate companies need to take a more proactive approach to societal relationships, which require both organizational and cultural change. Finally, the authors take the example from the safety journey, where the oil and gas industry has been very successful in demonstrating that excellence in safety is both a moral obligation and good for the bottom line. The same applies to excellence in societal relationships. Using the evolutionary model of safety culture with its maturity ladder as analogue, the authors provide a practical and value-driven framework to guide companies on their organizational and cultural change journey towards effective societal relationship management.

Attention to safety and health are of ever-increasing priority to industrial organizations. Good Safety is demanded by stockholders, employees, and the community while increasing injury costs provide additional motivation for safety and health excellence. Safety has always been a strong corporate value of DuPont and a vital part of its culture. As a result, DuPont has become a benchmark in safety and health performance. Since 1990, DuPont has re-engineered itself to meet global competition and address future vision. In the new re-engineered organizational structures, DuPont has also had to re-engineer its safety management systems. A special Discovery Team was chartered by DuPont senior management to determine the “best practices’ for safety and health being used in DuPont best-performing sites. A summary of the findings is presented, and five of the practices are discussed. Excellence in safety and health management is more important today than ever. Public awareness, federal and state regulations, and enlightened management have resulted in a widespread conviction that all employees have the right to work in an environment that will not adversely affect their safety and health. In DuPont, we believe that excellence in safety and health is necessary to achieve global competitiveness, maintain employee loyalty, and be an accepted member of the communities in which we make, handle, use, and transport products. Safety can also be the “catalyst” to achieving excellence in other important business parameters. The organizational and communication skills developed by management, individuals, and teams in safety can be directly applied to other company initiatives. As we look into the 21st Century, we must also recognize that new organizational structures (flatter with empowered teams) will require new safety management techniques and systems in order to maintain continuous improvement in safety performance. Injury costs, which have risen dramatically in the past twenty years, provide another incentive for safety and health excellence. Shown in the Figure 1, injury costs have increased even after correcting for inflation. Many companies have found these costs to be an “invisible drain” on earnings and profitability. In some organizations, significant initiatives have been launched to better manage the workers’ compensation systems. We have found that the ultimate solution is to prevent injuries and incidents before they occur. A globally-respected company, DuPont is regarded as a well-managed, extremely ethical firm that is the benchmark in industrial safety performance. Like many other companies, DuPont has re-engineered itself and downsized its operations since 1985. Through these changes, we have maintained dedication to our principles and developed new techniques to manage in these organizational environments. As a diversified company, our operations involve chemical process facilities, production line operations, field activities, and sales and distribution of materials. Our customer base is almost entirely industrial and yet we still maintain a high level of consumer awareness and positive perception. The DuPont concern for safety dates back to the early 1800s and the first days of the company. In 1802 E.I. DuPont, a Frenchman, began manufacturing quality grade explosives to fill America’s growing need to build roads, clear fields, increase mining output, and protect its recently won independence. Because explosives production is such a hazardous industry, DuPont recognized and accepted the need for an effective safety effort. The building walls of the first powder mill near Wilmington, Delaware, were built three stones thick on three sides. The back remained open to the Brandywine River to direct any explosive forces away from other buildings and employees. To set the safety example, DuPont also built his home and the homes of his managers next to the powder yard. An effective safety program was a necessity. It represented the first defense against instant corporate liquidation. Safety needs more than a well-designed plant, however. In 1811, work rules were posted in the mill to guide employee work habits. Though not nearly as sophisticated as the safety standards of today, they did introduce an important basic concept — that safety must be a line management responsibility. Later, DuPont introduced an employee health program and hired a company doctor. An early step taken in 1912 was the keeping of safety statistics, approximately 60 years before the federal requirement to do so. We had a visible measure of our safety performance and were determined that we were going to improve it. When the nation entered World War I, the DuPont Company supplied 40 percent of the explosives used by the Allied Forces, more than 1.5 billion pounds. To accomplish this task, over 30,000 new employees were hired and trained to build and operate many plants. Among these facilities was the largest smokeless powder plant the world had ever seen. The new plant was producing granulated powder in a record 116 days after ground breaking. The trends on the safety performance chart reflect the problems that a large new work force can pose until the employees fully accept the company’s safety philosophy. The first arrow reflects the World War I scale-up, and the second arrow represents rapid diversification into new businesses during the 1920s. These instances of significant deterioration in safety performance reinforced DuPont’s commitment to reduce the unsafe acts that were causing 96 percent of our injuries. Only 4 percent of injuries result from unsafe conditions or equipment — the remainder result from the unsafe acts of people. This is an important concept if we are to focus our attention on reducing injuries and incidents within the work environment. World War II brought on a similar set of demands. The story was similar to World War I but the numbers were even more astonishing: one billion dollars in capital expenditures, 54 new plants, 75,000 additional employees, and 4.5 billion pounds of explosives produced — 20 percent of the volume used by the Allied Forces. Yet, the performance during the war years showed no significant deviation from the pre-war years. In 1941, the DuPont Company was 10 times safer than all industry and 9 times safer than the Chemical Industry. Management and the line organization were finally working as they should to control the real causes of injuries. Today, DuPont is about 50 times safer than US industrial safety performance averages. Comparing performance to other industries, it is interesting to note that seemingly “hazard-free” industries seem to have extraordinarily high injury rates. This is because, as DuPont has found out, performance is a function of injury prevention and safety management systems, not hazard exposure. Our success in safety results from a sound safety management philosophy. Each of the 125 DuPont facilities is responsible for its own safety program, progress, and performance. However, management at each of these facilities approaches safety from the same fundamental and sound philosophy. This philosophy can be expressed in eleven straightforward principles. The first principle is that all injuries can be prevented. That statement may seem a bit optimistic. In fact, we believe that this is a realistic goal and not just a theoretical objective. Our safety performance proves that the objective is achievable. We have plants with over 2,000 employees that have operated for over 10 years without a lost time injury. As injuries and incidents are investigated, we can always identify actions that could have prevented that incident. If we manage safety in a proactive — rather than reactive — manner, we will eliminate injuries by reducing the acts and conditions that cause them. The second principle is that management, which includes all levels through first-line supervisors, is responsible and accountable for preventing injuries. Only when senior management exerts sustained and consistent leadership in establishing safety goals, demanding accountability for safety performance and providing the necessary resources, can a safety program be effective in an industrial environment. The third principle states that, while recognizing management responsibility, it takes the combined energy of the entire organization to reach sustained, continuous improvement in safety and health performance. Creating an environment in which employees feel ownership for the safety effort and make significant contributions is an essential task for management, and one that needs deliberate and ongoing attention. The fourth principle is a corollary to the first principle that all injuries are preventable. It holds that all operating exposures that may result in injuries or illnesses can be controlled. No matter what the exposure, an effective safeguard can be provided. It is preferable, of course, to eliminate sources of danger, but when this is not reasonable or practical, supervision must specify measures such as special training, safety devices, and protective clothing. Our fifth safety principle states that safety is a condition of employment. Conscientious assumption of safety responsibility is required from all employees from their first day on the job. Each employee must be convinced that he or she has a responsibility for working safely. The sixth safety principle: Employees must be trained to work safely. We have found that an awareness for safety does not come naturally and that people have to be trained to work safely. With effective training programs to teach, motivate, and sustain safety knowledge, all injuries and illnesses can be eliminated. Our seventh principle holds that management must audit performance on the workplace to assess safety program success. Comprehensive inspections of both facilities and programs not only confirm their effectiveness in achieving the desired performance, but also detect specific problems and help to identify weaknesses in the safety effort. The Company’s eighth principle states that all deficiencies must be corrected promptly. Without prompt action, risk of injuries will increase and, even more important, the credibility of management’s safety efforts will suffer. Our ninth principle is a statement that off-the-job safety is an important part of the overall safety effort. We do not expect nor want employees to “turn safety on” as they come to work and “turn it off” when they go home. The company safety culture truly becomes of the individual employee’s way of thinking. The tenth principle recognizes that it’s good business to prevent injuries. Injuries cost money. However, hidden or indirect costs usually exceed the direct cost. Our last principle is the most important. Safety must be integrated as core business and personal value. There are two reasons for this. First, we’ve learned from almost 200 years of experience that 96 percent of safety incidents are directly caused by the action of people, not by faulty equipment or inadequate safety standards. But conversely, it is our people who provide the solutions to our safety problems. They are the one essential ingredient in the recipe for a safe workplace. Intelligent, trained, and motivated employees are any company’s greatest resource. Our success in safety depends upon the men and women in our plants following procedures, participating actively in training, and identifying and alerting each other and management to potential hazards. By demonstrating a real concern for each employee, management helps establish a mutual respect, and the foundation is laid for a solid safety program. This, of course, is also the foundation for good employee relations. An important lesson learned in DuPont is that the majority of injuries are caused by unsafe acts and at-risk behaviors rather than unsafe equipment or conditions. In fact, in several DuPont studies it was estimated that 96 percent of injuries are caused by unsafe acts. This was particularly revealing when considering safety audits — if audits were only focused on conditions, at best we could only prevent four percent of our injuries. By establishing management systems for safety auditing that focus on people, including audit training, techniques, and plans, all incidents are preventable. Of course, employee contribution and involvement in auditing leads to sustainability through stakeholdership in the system. Management safety audits help to make manage the “behavioral balance.” Every job and task performed at a site can do be done at-risk or safely. The essence of a good safety system ensures that safe behavior is the accepted norm amongst employees, and that it is the expected and respected way of doing things. Shifting employees norms contributes mightily to changing culture. The management safety audit provides a way to quantify these norms. DuPont safety performance has continued to improve since we began keeping records in 1911 until about 1990. In the 1990–1994 time frame, performance deteriorated as shown in the chart that follows: This increase in injuries caused great concern to senior DuPont management as well as employees. It occurred while the corporation was undergoing changes in organization. In order to sustain our technological, competitive, and business leadership positions, DuPont began re-engineering itself beginning in about 1990. New streamlined organizational structures and collaborative work processes eliminated many positions and levels of management and supervision. The total employment of the company was reduced about 25 percent during these four years. In our traditional hierarchical organization structures, every level of supervision and management knew exactly what they were expected to do with safety, and all had important roles. As many of these levels were eliminated, new systems needed to be identified for these new organizations. In early 1995, Edgar S. Woolard, DuPont Chairman, chartered a Corporate Discovery Team to look for processes that will put DuPont on a consistent path toward a goal of zero injuries and occupational illnesses. The cross-functional team used a mode of “discovery through learning” from as many DuPont employees and sites around the world. The Discovery Team fostered the rapid sharing and leveraging of “best practices” and innovative approaches being pursued at DuPont’s plants, field sites, laboratories, and office locations. In short, the team examined the company’s current state, described the future state, identified barriers between the two, and recommended key ways to overcome these barriers. After reporting back to executive management in April, 1995, the Discovery Team was realigned to help organizations implement their recommendations. The Discovery Team reconfirmed key values in DuPont — in short, that all injuries, incidents, and occupational illnesses are preventable and that safety is a source of competitive advantage. As such, the steps taken to improve safety performance also improve overall competitiveness. Senior management made this belief clear: “We will strengthen our business by making safety excellence an integral part of all business activities.” One of the key findings of the Discovery Team was the identification of the best practices used within the company, which are listed below: ▪ Felt Leadership – Management Commitment ▪ Business Integration ▪ Responsibility and Accountability ▪ Individual/Team Involvement and Influence ▪ Contractor Safety ▪ Metrics and Measurements ▪ Communications ▪ Rewards and Recognition ▪ Caring Interdependent Culture; Team-Based Work Process and Systems ▪ Performance Standards and Operating Discipline ▪ Training/Capability ▪ Technology ▪ Safety and Health Resources ▪ Management and Team Audits ▪ Deviation Investigation ▪ Risk Management and Emergency Response ▪ Process Safety ▪ Off-the-Job Safety and Health Education Attention to each of these best practices is essential to achieve sustained improvements in safety and health. The Discovery Implementation in conjunction with DuPont Safety and Environmental Management Services has developed a Safety Self-Assessment around these systems. In this presentation, we will discuss a few of these practices and learn what they mean. Paper published with permission.