CO2Laser Cutting, 2nd Edition, 
John Powell. 1998. Springer-Verlag. 248 pp. $79.95. ISBN 1-852-33047-3.

This book treats the most widespread application of high-power laser materials processing, that is, CO2 laser cutting. Although called CO2 laser cutting, most of the content of the book is also valid for cutting with other lasers such as Nd:YAG or Cu Vapor lasers. The technology is described in a very useful style by emphasizing practical aspects and by replacing highly scientific phrases by clear, illustrative explanations. Nevertheless, this guide through the complex field of laser cutting is accompanied by critical physical explanations throughout the whole book. It should be emphasized that Dr. Powell is the technical director of two job shops on laser cutting, but has also been highly active in science for many years. This ideal combination of practical experience with scientific know-how is reflected throughout the whole book by highlighting the practical aspects of laser cutting, often accompanied by very critical scientific explanations. It should be noted that the present second edition of the book differs from the first edition, printed in 1993, only by several pages that had to be updated according to the state of the art.

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Achievements and Current Issues in Decommissioning of Research Reactors

9th ASME International Conference on Radioactive Waste Management and Environmental Remediation: Volumes 1, 2, and 3 ◽

10.1115/icem2003-4634 ◽

2003 ◽

Author(s):

Michele Laraia

Keyword(s):

State Of The Art ◽

Nuclear Research ◽

Practical Experience ◽

Financial Resources ◽

Extended State ◽

Member States ◽

Staff Morale ◽

Research Reactors ◽

Know How ◽

Learning From Others

Although the state-of-the-art technology for decommissioning nuclear research reactors is probably adequate to cope with most difficulties associated with the dismantling of such facilities, it is generally imperative to improve, adapt or optimise technologies for the specific needs of the reactor to be dismantled. Learning from others rather than re-inventing the wheel makes sense in today’s globalisation context. This approach is expected to match the needs of many developing countries. The objective of the IAEA’s Co-ordinated Research Project (CRP) on Decommissioning Techniques for Research Reactors was to promote the exchange of information on the practical experience gained by Member States in decommissioning or operation, maintenance, and refurbishment activities which would be eventually related to the decommissioning of research reactors. Special emphasis was given to the development/adaptation of methods and approaches for optimisation of the decommissioning process. Fourteen institutions from thirteen Member States of the IAEA took part in this CRP that lasted from 1997 to 2002. It is felt that the IAEA project succeeded in transferring information and know-how from active decommissioning projects to those planning for decommissioning. It is also expected that this project will draw Member States’ attention to the need for timely planning for and implementation of decommissioning. In some Member States there are research reactors that are kept in an extended state of shutdown, pending decisions on continued operation, extensive refurbishment or decommissioning. This situation — which frequently lasts for many years — weighs heavily on staff morale and motivation, state resources, entails deterioration of structures and components, and may in the longer term have very serious safety implications. The IAEA project is expected to offer the Member States the opportunity of considering financial and other impacts of decommissioning research reactors, so that decommissioning actions can be initiated without undue delay. Aspects such as fuel and waste management and provisions for other technical, administrative and financial resources require timely preparation.

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Wavelength dependency in high power laser cutting and welding

10.1117/12.906811 ◽

2012 ◽

Cited By ~ 1

Author(s):

David Havrilla ◽

Stephan Ziermann ◽

Marco Holzer

Keyword(s):

High Power ◽

Laser Cutting ◽

High Power Laser ◽

Power Laser

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Detection of Corrosion Damage on Pressure Equipment with Acoustic Emission

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.13-14.127 ◽

2006 ◽

Vol 13-14 ◽

pp. 127-132 ◽

Cited By ~ 1

Author(s):

Gerold Lackner ◽

Peter Tscheliesnig

Keyword(s):

Acoustic Emission ◽

Test Procedure ◽

Corrosion Damage ◽

Practical Experience ◽

Pressure Vessels ◽

Destructive Testing ◽

Widespread Application ◽

Traditional Procedure ◽

Emission Testing ◽

Service Period

Acoustic emission testing (AT) is in Europe an already well established non-destructive testing (NDT) method. Qualification requirements as well as certification of testing personnel are laid down in European standard EN 473. A widespread application of AT deals with testing of unfired pressure vessels for re-qualification after a certain period of service (repetition test). The advantages of applying AT compared to the traditional procedure of hydrostatic test plus visual inside inspection are numerous. Just to name the most important: reduction of downtime, omitting of residual humidity and no risk of product contamination with water. It is a fact that AT provides much more useful information concerning the condition of the pressure vessel under test than a simple ‘passed’ or ‘not passed’ obtained usually by a hydrostatic test. This contribution gives two examples of practical experience, where severe corrosion defects have been detected by AT. The defects have been found in both cases on the vessel’s shell under the thermal insulation, where they have been hidden undetected for years. It can be assumed that even the vessel with the most severe damage (loss of more than 50% of the nominal wall thickness) would have passed the traditional repetition test procedure and that failure within the following service period would have occurred. In contrary to this scenario, AT enabled the vessel operator to perform appropriate repair in time.

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Laser cutting: From first principles to the state of the art

Pacific International Conference on Applications of Lasers and Optics ◽

10.2351/1.5056075 ◽

2004 ◽

Cited By ~ 7

Author(s):

J. Powell ◽

A. Kaplan

Keyword(s):

First Principles ◽

Laser Cutting ◽

State Of The Art ◽

The State

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Applicability of various beam sources for high power laser cutting of non-oriented electrical steel

10.1117/12.907832 ◽

2012 ◽

Author(s):

René Siebert ◽

Harry Thonig ◽

Andreas Wetzig ◽

Eckhard Beyer

Keyword(s):

High Power ◽

Laser Cutting ◽

Electrical Steel ◽

High Power Laser ◽

Power Laser

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Graph Neural Networks Meet Neural-Symbolic Computing: A Survey and Perspective

Proceedings of the Twenty-Ninth International Joint Conference on Artificial Intelligence ◽

10.24963/ijcai.2020/679 ◽

2020 ◽

Cited By ~ 2

Author(s):

Luís C. Lamb ◽

Artur d’Avila Garcez ◽

Marco Gori ◽

Marcelo O.R. Prates ◽

Pedro H.C. Avelar ◽

...

Keyword(s):

Neural Networks ◽

Constraint Satisfaction ◽

State Of The Art ◽

Relational Reasoning ◽

Widespread Application ◽

Symbolic Computing ◽

Industry Research ◽

Optimization Constraint ◽

The Subject ◽

Graph Neural Networks

Neural-symbolic computing has now become the subject of interest of both academic and industry research laboratories. Graph Neural Networks (GNNs) have been widely used in relational and symbolic domains, with widespread application of GNNs in combinatorial optimization, constraint satisfaction, relational reasoning and other scientific domains. The need for improved explainability, interpretability and trust of AI systems in general demands principled methodologies, as suggested by neural-symbolic computing. In this paper, we review the state-of-the-art on the use of GNNs as a model of neural-symbolic computing. This includes the application of GNNs in several domains as well as their relationship to current developments in neural-symbolic computing.

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Retained Austenite Benefits or Avoidance Requires Dependable Determination

10.31399/asm.cp.ht2021p0212 ◽

2021 ◽

Author(s):

Thomas Wingens

Keyword(s):

Retained Austenite ◽

State Of The Art ◽

Practical Experience ◽

X Ray ◽

Heat Treated ◽

Individual Solution ◽

The Right

Abstract Retained austenite can be disastrous or increase the life of heat treated components. However, discussions on the right amount of retained austenite are only meaningful when measured correctly. The proper determination in microstructures samples requires a trained metallurgist and remains to be very subjective to the individual’s eye. Company standards of microstructure tables are used as individual solution. However, factual results are only achievable with the use of an X-ray diffractometer. This paper discusses the practical experience of metallurgical results and shows state of the art solutions as today’s standard.

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Kertsopoulos Innovation: The Three Multi-plane Polarities and the Three Interactions and Schematic Representations in the Sense of the General Cause of the Dynamic Difference

Advances in Nanoscience and Nanotechnology ◽

10.33140/ann.03.01.07 ◽

2019 ◽

Vol 3 (1) ◽

Keyword(s):

Magnetic Fields ◽

Magnetic System ◽

State Of The Art ◽

Magnetic Devices ◽

Know How ◽

Patented Invention ◽

Scientific Laws ◽

First Time ◽

Multiple Interactions

As it is known: in the state of the art, the like and the unlike polarity between two magnets remains independent of the distance between them. According to the invention: “Magnetic System of Three Interactions”, International office of patents WIPO-PCT, bearing the No WO/2013/136097of the inventor Georgios K. Kertsopoulos, the like and the unlike polarity between two magnetic constructions depends on the distance between them [1], [2], [3], [4], [5], [6], [7], [8], [9], [10]. The know-how of the invention makes it possible for interacting magnetic constructions to possess and perform interchangeable more than 96 polarities and interactions. Polarities and magnetic fields can in multiple ways interchange, depending on the varying distance between two interacting confronted magnetic constructions, offering many new variable design capabilities. For the first time, new types of poles are created, for example: simultaneous like-unlike poles or simultaneous unlike-like poles are created, causing stable or unstable balance as an interaction; also, for the first time in magnetism, new types of magnetic fields are formed never before observed, for example: remote fields of very strong attraction, without however, the contact of the magnetic constructions. The magnetic devices that perform these multiple interactions are fully patented internationally, published in a book in English, by the inventor a book in English, by the inventor [11]. The new scientific laws and principles, revealed through these experiments enrich the very basics, the foundation of magnetism, since many new types of polarities and interactions are introduced and are made possible for the first time in science and technology. In figure 1 of the article we observe the division and determination of the empty air space, between the magnetic constructions, at three distances and two boundaries which apply both for the like and the unlike front poles and in figure 2 we observe the three typical spatial distances, the three multi-plane polarities and the three interactions with properties and with spatial boundaries and interactions based on the bundles of the dynamic lines between the two magnetic constructions, on the guide, when the poles of the front poles of the arrangements are initially like. Furthermore, in figure 7 we observe a schematic representation of the three different fields (175), (177) and (178) between the above-mentioned magnetic arrangements of the constructions of the invention, with initially like front poles, in the sense of the general cause of the dynamic difference. This article is in continuation of the following published article that introduces the reader to the invention’s technology: Georgios K. Kertsopoulos (2018) Innovation article: 36 over passed restrictions of magnetism achieved by the 96 multiple magnetic polarities-interactions performed by the Kertsopoulos world patented invention vs. the known two. Advances in Nanoscience and nanotechnology [12]. https://www.opastonline.com/wp-content/uploads/2018/12/36-over-passed-restrictions-of-magnetism-achieved-by-the-96- multiple-magnetic-polarities-interactions-performed-by-the-kertsopoulos-world-ann-18.pdf?fbclid=IwAR1jYPFME5mhX2FLbKKTPAdu0YMe3FqHtoUdoRoeao8mKIp1GRuWeovEaA

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Effect of Laser Beam Diameter on Cut Edge of Steel Plates Obtained by Laser Machining

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.467.227 ◽

2013 ◽

Vol 467 ◽

pp. 227-232 ◽

Cited By ~ 4

Author(s):

Imed Miraoui ◽

Mouna Zaied ◽

Mohamed Boujelbene

Keyword(s):

Laser Beam ◽

Laser Cutting ◽

Steel Plates ◽

Beam Diameter ◽

Power Laser ◽

Laser Beam Diameter ◽

Machined Surface ◽

Cut Edge ◽

Thermal Influence ◽

Cut Surface

Laser cutting is a thermal process which is used contactless to separate materials. In the present study, high-power laser cutting of steel plates is considered and the thermal influence of laser cutting on the cut edges is examined. The microstructure and the microhardness of the cut edge are affected by the input laser cutting parameter: laser beam diameter. The aim of this work is to investigate the effect of the laser beam diameter on the microhardness beneath the cut surface of steel plates obtained by CO2 laser cutting. The cut surface was studied based on microhardness depth profiles beneath the machined surface. The results show that laser cutting has a thermal effect on the surface microstructure and on the microhardness beneath the cut section. Also the microhardness of the hardening zone depends on the laser beam diameter.

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