319 research outputs found
Confinement and chiral symmetry breaking in heavy-light quark systems
Assuming a Gaussian approximation for the QCD gluodynamics, all the
nonperturbative physics can be encoded into two parameters: the gluon
correlation length and the gluon condensate . These parameters are
sufficient in order to describe the heavy-heavy quark nonperturbative
interaction. In this work we adopt the same framework in order to study
heavy-light bound states in the non-recoil limit. Spontaneous chiral symmetry
breaking and a confining chiral non-invariant interaction emerge quite
naturally. The gap equation is solved and discussed. In particular a relation
between the light quark condensate and is derived. The energy spectrum
for the bound state equation is evaluated and commented.Comment: 15 pages, 2 figures, elsart.st
Ageing and creeping management in major accident plants according to seveso III directive
The focus of this paper is the management of critical equipment ageing within the context of lower and upper tier Seveso process plants, with a peculiar insight into the effectiveness of safety management systems in setting-up reliable procedure for critical element identification. Recent research studies in fact evidenced that in Europe nearly 50% of major 'loss of containment' events, arising from technical plant failures, were primarily due to ageing plant mechanisms such as erosion, corrosion and fatigue. The critical ageing elements should be included in maintenance, inspection and periodic monitoring programs in relation to their reliability, as assumed in the risk assessment and their lifetime or frequency ranges, based on their operational experience. This paper will accurately discuss how the issue of ageing is currently handled in the process industry. The methodology builds on the critical results of actual findings from the inspections on the safety management systems of major accident plants, which were performed by a working group. The primary objective is to stimulate the introduction of effective ageing management changes into the safety management of companies, by taking advantages of findings of the previous assessment and establishing proper and effective audits
A Bayesian belief network for local air quality forecasting
This study is focused on the development of a Bayesian network for air quality assessment and aims at offering a pragmatic and scientifically credible approach to modelling complex systems where substantial uncertainties exist. In particular, the main object is the prediction of the occurrence of suitable conditions for the stagnation of pollutants in a given area. The analytical modeling of the network provides a set of independent nodes, represented by the outputs of a forecasting meteorological Limited Area Model, from which descend the conditions for the stagnation of pollutants in different areas of the city (through measurements of the heuristic pollutant from monitoring stations) and finally the global conditions. The urban area of Genoa (Italy) was selected in order to test the actual capability of the model prototype. Network training was performed by means of historical data resulting from significant statistical series of the past years by the air quality-monitoring network. The system used for data assimilation, construction and network learning is completely based on an open source statistical processing software
Organic Action Plans. Development, implementation and evaluation. A resource manual for the organic food and farming sector
In 2004, the European Action Plan for Organic Food and Farming was launched. Many European countries have also developed national Organic Action Plans to promote and support organic agriculture.
As part of the EU funded ORGAP project (âEuropean Action Plan of Organic Food and Farming - Development of criteria and procedures for the evaluation of the EU Action Plan for Organic Agricultureâ) a toolbox to evaluate and monitor the implementation of national and European Action Plans has been developed.
In order to communicate the results of this project as widely as possible, a practical manual for initiating and evaluating Organic Action Plans has been produced.
This manual has been created to inspire the people, organisations and institutions involved, or with an interest, in the organic food and farming sector to engage in the initiation, review, revision and renewal of regional, national and European Organic Action Plans.
The objectives of the manual are to provide:
âą a tool for stakeholder involvement in future Action Plan development and implementation processes at EU, national and regional level
âą a guide to the use of the Organic Action Plan Evaluation Toolbox (ORGAPET) developed through the project
The manual summarises the key lessons learnt from more than 10 years experience of development, implementation and evaluation of Organic Action Plans throughout Europe.
The Organic Action Plan Evaluation Toolbox (ORGAPET), which includes comprehensive
information to support the Organic Action Plan development and evaluation process is included with the manual as a CD-ROM, and is also accessible on-line at www.orgap.org/orgapet.
The ORGAP website www.orgap.org provides a further information on the project
and the European and national organic action plans.
Published by: Research Institute of Organic Agriculture (FiBL), Frick, Switzerland; IFOAM EU Group, Brussels
Table of contents
Foreword 1
1 Introduction 3
1.1 About this manual 3
1.2 Organic farming â origins, definition & principles 6
1.3 Development of organic food & farming in Europe 8
1.3.1 Organic food and farming regulation in Europe 10
1.3.2 Policy support for organic food and farming in Europe 11
2 Organic Action Plans â what are they about? 16
2.1 Why Organic Action Plans? 16
2.2 European Organic Action Plan 21
2.3 Overview of national and regional Organic Action Plans 23
3 Planning and implementing Organic Action Plans 28
3.1 Policy development 28
3.2 Defining organic sector development needs and potential 31
3.3 Defining policy goals and objectives 34
3.4 Involving stakeholders 40
3.4.1 The case for stakeholder involvement 40
3.4.2 Identifying relevant stakeholders 42
3.4.3 Participatory approaches for stakeholders involvement 44
3.5 Decision making: selecting, integrating and prioritising
relevant measures 46
3.5.1 Deciding on policy instruments and action points 47
3.5.2 Priorities for action â allocating resources 50
3.6 Implementing Organic Action Plans 52
3.7 Including monitoring and evaluation of Organic Action Plans
from outset 56
3.8 Managing communication 58
3.9 Development of Action Plans in countries that joined the
EU in 2004 and later 59
4 Evaluating Organic Action Plans 61
4.1 Principles of evaluation 61
4.2 Conducting an evaluation 64
4.3 Evaluating Action Plan design and implementation 70
4.3.1 Evaluating programme design and implementation processes 70
4.3.2 Evaluating programme coherence 72
4.3.3 Evaluating stakeholder involvement 74
4.4 Evaluating Action Plan effects 78
4.4.1 Developing and using indicators for evaluation 78
4.5 Overall evaluation of Organic Action Plans â judging success 85
4.6 Evaluating Action Plans in countries that joined the EU
in 2004 and later 89
5 Organic Action Plans â the Golden Rules 91
5.1 Key elements of Organic Action Plan development 91
5.2 The Golden rules for Organic Action Plan 93
References 96
Annex Detailed synopsis of ORGAPET 10
An oil pipeline catastrophic failure: Accident scenario modelling and emergency response development
In spite of advanced technologies, inherent safety and safety management system, pipeline loss of containments and large-scale releases of hazardous substances are still common accidents leading to severe consequences for human health, environment and assets, both in Europe and in developing Countries. This paper presents a detailed analysis of the catastrophic failure of a pipeline connecting the port oil terminal with a downstream oil plant, in the North part of Italy, causing a major oil spill into a river and subsequently into the Genoa harbor (Italy). Firstly, the impact of atmospheric dispersion is evaluated then, assuming oil containment failure, the hydrodynamic dispersion of the spill into the sea is studied. By means of numerical methods, we performed a consequence-based assessment incorporating the effects, the hazardous distance and the reaction time scale, related to oil spill. Results are focused on the atmospheric dispersion of the "key" oil volatile fractions and the propagation in the sea of the medium-heavy fractions, both performed by Lagrangian simulations
Make Bow-tie Dynamic by Rethinking it as a Hierarchical Bayesian Network. Dynamic Risk Assessment of an LNG Bunkering Operation
In the present era, the spread of cyber-physical systems in the framework of the so-called Industry 4.0, is leading towards a complete automation of industrial processes, which are increasingly decentralized, smart, and require fewer and fewer frontline personnel. The risk assessment process is certainly not excluded from the revolution, and in perspective needs to be automatic, dynamic and linked with the conditions that emerge, moment by moment, in the life of a complex system. Analytical techniques can help in converting data in information and hence system knowledge to spot trends in operational performance, thus improving risk assessment quality. Even though the bow-tie approach is widely used within the context of complex systems, it still evidences several limitations, mainly connected to the actual assessment of likelihood and interdependencies in the fault and event trees. This paper shows how a bow tie analysis can be reframed as a Hierarchical Bayesian Network, where the probability distributions of the network nodes are updated with real time predictions during the operations. The proposed model was then applied to the risk assessment of a shore-to-ship LNG bunkering operation
Codes and standards on computational wind engineering for structural design: State of art and recent trends
This paper first provides a wide overview about the design codes and standards covering the use of Computational Wind Engineering / Computational Fluid Dynamics (CWE/CFD) for wind-sensitive structures and built environment. Second, the paper sets out the basic assumptions and underlying concepts of the new Annex T "Simulations by Computational Fluid Dynamics (CFD/CWE)" of the revised version "Guide for the assessment of wind actions and effects on structures" issued by the Advisory Committee on Technical Recommendations for Constructions of the Italian National Research Council in February 2019 and drafted by the members of the Special Interest Group on Computational Wind Engineering of the Italian Association for Wind Engineering (ANIV-CWE). The same group is currently advising UNI CT021/SC1 in supporting the drafting of the new Annex K - "Derivation of design parameters from wind tunnel tests and numerical simulations" of the revised Eurocode 1: Actions on structures - Part 1-4: General actions - Wind actions. Finally, the paper outlines the subjects most open to development at the technical and applicative level
Quarkonium in Hot Medium
I review recent progress in studying quarkonium properties in hot medium as
well as possible consequences for quarkonium production in heavy ion
collisions.Comment: Invited talk at SQM 2009, Buzios, Brazil, Sep. 27 -Oct. 2 2009,
LaTeX, 8 pages,3 figures; typos corrected, references adde
A path integral for heavy-quarks in a hot plasma
We propose a model for the propagation of a heavy-quark in a hot plasma, to
be viewed as a first step towards a full description of the dynamics of heavy
quark systems in a quark-gluon plasma, including bound state formation. The
heavy quark is treated as a non relativistic particle interacting with a
fluctuating field, whose correlator is determined by a hard thermal loop
approximation. This approximation, which concerns only the medium in which the
heavy quark propagates, is the only one that is made, and it can be improved.
The dynamics of the heavy quark is given exactly by a quantum mechanical path
integral that is calculated in this paper in the Euclidean space-time using
numerical Monte Carlo techniques. The spectral function of the heavy quark in
the medium is then reconstructed using a Maximum Entropy Method. The path
integral is also evaluated exactly in the case where the mass of the heavy
quark is infinite; one then recovers known results concerning the complex
optical potential that controls the long time behavior of the heavy quark. The
heavy quark correlator and its spectral function is also calculated
semi-analytically at the one-loop order, which allows for a detailed
description of the coupling between the heavy quark and the plasma collective
modes
Understanding the Vulnerability of Complex Systems. An Integrated Approach
The increasing complexity of current system realities (e.g., pandemics, healthcare, energy transition, process industry 4.0 etc.) would require the evaluation of the actual way systems are modified, often referred with âwork as doneâ, rather than âwork as imaginedâ. The safety of a complex system is one of the emergent properties depending upon the interactions between the system's components and subsystems. This paper is focused on the analysis of the nature of the interactions within a complex system when it is subjected to cumulative stresses, crises and accidents. The objective is to identify, test and validate integrated emergency management procedures in the event of accidents, crises or major incidents occurring during the loading and unloading of goods and hazardous substances. To test the applicability of the framework, we developed a prototypal application identifying as a target complex system an Italian port area. An interactive simulation model was ad-hoc designed and developed, which makes it possible to reproduce the evolution of the crisis and its impact on structures, systems, people and goods by considering both the physical aspects and the domino effect in a multiple/sequential accidental scenario simulation. Additionally, it is possible testing the effectiveness of new technological and infrastructural solutions to reduce vulnerability, mitigate damage and prevent possible escalation of the event. Relevant accident scenarios were firstly thoroughly selected and subsequently integrated into a digital twin of the port. The interactivity allows a dynamic simulation of the possible actions of the different elements and active subsystems considered as a complex system, exploring their interactions in the face of crises and disasters, including the determining role of human factor
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