Retardation effects due to overloads in aluminium-alloy aeronautical components

Fatigue data are generally derived under constant-amplitude loading conditions, but aircraft components are subjected to variable-amplitude loading. Without interaction effects, caused by overloads and underloads intermingled in a loading sequence, it could be relatively easy to establish a crack growth curve by means of a cycle-by-cycle integration. However, load-spectrum effects largely complicate a crack growth under variable-amplitude cycling. In this paper, fatigue crack growth behaviour of aeronautical aluminium alloy 2024-T3 was studied. Effects of various loading conditions such as stress ratio and amplitude loadings were investigated. In particular, the effect of different overloads on the fatigue crack growth was simulated using Zencrack code. Preliminary analyses on Compact Tension (CT) specimens proved that the numerical results generated were in agreement with the results provided by an afgrow code for the same conditions. A case study was carried out on a helicopter component, undergoing repeated overloads, to compare numerical results obtained implementing yield zone models in Zencrack.N/

European Tourism Regionalization and Globalisation

The advent of the Third Millenium, as do all periods of transition, offers the starting point for proceeding towards a new interpretation of the process of development in the field of tourism which enterprise appears to lend itself as a contribution towards the achievement of certain objectives or aims of the European Union (UE), such as the protection of the environment, sustainable development, the improvement of the quality of living standards, the overcoming of conflicts for enduring peace, the growth of European regions and of employment and not least the enacting of a policy of cohesion. During recent years numerous factors such as the globalisation of the economy, the new economy, a better functioning of a single Market and the introduction of the Euro currency have all contributed to a greater internationalisation of the streams/flows and at the same time, have obliged Member states to face new challenges, which can either constitute opportunities or risks, according to the actions which will be undertaken and according to the capacity of anticipation, programming and managing of such change. On such a premise will be founded the necessity to select an integrated policy of tourism on a communitary level which, taking into consideration the specificity of the relevant sectors, will guarantee the European Community its place as representative of the most important geographical space on the world tourist market.

Sustainable Development Planning in Kosovo

After eighteen months of intense preparation and work, in April 2003 the signing of MEMORANDUM OF COOPERATIVE RESEARCH between the NORTH ATLANTIC TREATY ORGANIZATION’S REGIONAL HEADQUARTERS ALLIED FORCES SOUTHERN EUROPE (AFSOUTH) and the DEPARTMENT FOR STUDIES ON THE ENVIRONMENT AND TERRITORY (DISAT) of the UNIVERSITY OF SALERNO was finalised. Within the framework of cooperation set up between NATO (AFSOUTH – NAPOLI) and DiSAT, we have been invited to carry out activities of study and research regarding the complex social, economic and security problems in Kosovo. Therefore, with the aim of contributing to the consolidation of the process of peace and development in Kosovo, interdisciplinary research has been carried out in the Region last September, preliminary to the drawing up of a REPORT ON SUSTAINABLE DEVELOPMENT PLANNING IN KOSOVO. The concept of security, traditionally seen from a purely military perspective, has gradually grown to embrace economic aspects, political-cultural aspects as well as others of a different nature. To guarantee security, then, means not so much or at least, not only, to increase the weight of traditional power factors but rather to reduce to a minimum the conditions of specific vulnerability. Functional to this aim would be to achieve an accurate analysis in order to consent the recommending of such actions that could avoid the most critical and dangerous union of forces. A return to the study then of the problems that encourage these phenomena, their dimension and collocation in space appears to be the longest and most laborious way but also the only one possible. An analysis of the present day economic and political questions in the region must not neglect, furthermore, the considerable imbalances existing in the region between population and uses of the resources. Infact, the report, after having indicated the principal lines of development, follows with the formulation of projects well inserted into a strategic framework, so as to overcome the gap existing between plans, programmes, laws and recommendations on the one hand and real capacity and determination to succeed on the other.

Sustainable Development Planning in Kosovo

After eighteen months of intense preparation and work, in April 2003 the signing of MEMORANDUM OF COOPERATIVE RESEARCH between the NORTH ATLANTIC TREATY ORGANIZATION'S REGIONAL HEADQUARTERS ALLIED FORCES SOUTHERN EUROPE (AFSOUTH) and the DEPARTMENT FOR STUDIES ON THE ENVIRONMENT AND TERRITORY (DISAT) of the UNIVERSITY OF SALERNO was finalised. Within the framework of cooperation set up between NATO (AFSOUTH – NAPOLI) and DiSAT, we have been invited to carry out activities of study and research regarding the complex social, economic and security problems in Kosovo. Therefore, with the aim of contributing to the consolidation of the process of peace and development in Kosovo, interdisciplinary research has been carried out in the Region last September, preliminary to the drawing up of a REPORT ON SUSTAINABLE DEVELOPMENT PLANNING IN KOSOVO. The concept of security, traditionally seen from a purely military perspective, has gradually grown to embrace economic aspects, political-cultural aspects as well as others of a different nature. To guarantee security, then, means not so much or at least, not only, to increase the weight of traditional power factors but rather to reduce to a minimum the conditions of specific vulnerability. Functional to this aim would be to achieve an accurate analysis in order to consent the recommending of such actions that could avoid the most critical and dangerous union of forces. A return to the study then of the problems that encourage these phenomena, their dimension and collocation in space appears to be the longest and most laborious way but also the only one possible. An analysis of the present day economic and political questions in the region must not neglect, furthermore, the considerable imbalances existing in the region between population and uses of the resources. Infact, the report, after having indicated the principal lines of development, follows with the formulation of projects well inserted into a strategic framework, so as to overcome the gap existing between plans, programmes, laws and recommendations on the one hand and real capacity and determination to succeed on the other

European Tourism Regionalization and Globalisation

The advent of the Third Millenium, as do all periods of transition, offers the starting point for proceeding towards a new interpretation of the process of development in the field of tourism which enterprise appears to lend itself as a contribution towards the achievement of certain objectives or aims of the European Union (UE), such as the protection of the environment, sustainable development, the improvement of the quality of living standards, the overcoming of conflicts for enduring peace, the growth of European regions and of employment and not least the enacting of a policy of cohesion. During recent years numerous factors such as the globalisation of the economy, the new economy, a better functioning of a single Market and the introduction of the Euro currency have all contributed to a greater internationalisation of the streams/flows and at the same time, have obliged Member states to face new challenges, which can either constitute opportunities or risks, according to the actions which will be undertaken and according to the capacity of anticipation, programming and managing of such change. On such a premise will be founded the necessity to select an integrated policy of tourism on a communitary level which, taking into consideration the specificity of the relevant sectors, will guarantee the European Community its place as representative of the most important geographical space on the world tourist market

Development and Security in Southern Europe and the Mediterranean Area

Over the course of the years, the Mediterranean region has been analysed from many different perspectives and defined on the basis of the specific approach followed at the time (i.e. historic-cultural political, economical, functional etc.). On this occasion I would like to avoid ulterior interpretations and focus attention above all on the need for a course of development to guarantee security in Southern Europe. I don't want to suggest that Europe should take on the role of a top power, but rather, that Europe can aspire to leadership, in a certain sense, considering that capitalist globalisation has in the meantime become consolidated and that space for independent strategies that are not those of the management of well constituted interests, has been removed. It has been opportune and right to concentrate on the East of Europe over the last ten years, but on the twenty first century's agenda of security and development we should not underestimate the relevance of the Mediterranean. For the countries of the Mediterranean, therefore, there is no other alternative, and for the European countries the alternative remains that of the "wall"; a project not only immoral but also unfeasible because as history has demonstrated, divisions never support the drive of men. From these considerations which emerged during the course of my studies and research, the idea of elaborating a "MASTER PLAN FOR THE MEDITERRANEAN AREA", gradually took shape, in which the roles of the individual territories, the duties of the institutional subjects and the actions to undertake in a co-ordinated way, in the light of (a) a new international order and (b) the disparity and the different directions of the forces in the field

Multiple crack propagation in friction stir welded aluminium joints

This paper is concerned with the simulation of crack propagation in friction stir welded butt joints, in order to assess the influence of process induced microstructural alterations and residual stresses on the fatigue behaviour of the assembly. The approach employed is based on the coupled use of the finite element method and the dual boundary element method in order to take advantage of the main capabilities of the two methods. The distribution of the process induced residual stresses has been mapped by means of the contour method. Then, the computed residual stresses field has been superimposed, in a dual boundary element environment, to the stress field as a result of a remote fatigue traction load and the crack growth is simulated. A two-parameter crack growth law, based on the evaluation of two thresholds, for the material being analysed, is used for the crack propagation rate assessment. The stress intensity factors are evaluated using the J-integral technique. Computational results have been compared with experimental data, provided from constant amplitude crack propagation tests on welded samples, showing the subdivision of the overall fatigue life in the two periods of crack initiation and crack propagation

FEM simulation of a crack propagation in a round bar under combined tension and torsion fatigue loading

An edge crack propagation in a steel bar of circular cross-section undergoing multiaxial fatigue loads is simulated by Finite Element Method (FEM). The variation of crack growth behaviour is studied under axial and combined in phase axial+torsional fatigue loading. Results show that the cyclic Mode III loading superimposed on the cyclic Mode I leads to a fatigue life reduction. Numerical calculations are performed using the FEM software ZENCRACK to determine the crack path and fatigue life. The FEM numerical predictions have been compared against corresponding experimental and numerical data, available from literature, getting satisfactory consistencyN/

Prevention of Dermatologic Side Effects of Bimatoprost 0.03% Topical Therapy

PURPOSE: To investigate the efficacy of reducing the drop-skin contact to prevent dermatologic side effects of bimatoprost 0.03% topical therapy. DESIGN: Prospective, randomized, single-blinded, internally controlled study. METHODS: Enrolled subjects started bimatoprost 0.03% therapy once at night in both eyes and were instructed to wipe selectively only one eye (eye 1) with an adsorbent pad during and after drops administration for four months. The fellow eye acted as the internal control. Eyelash growth, regional skin hypertrichosis, and pigmentation on the periocular skin were assessed at baseline and during the four months of follow-up. RESULTS: A lower incidence of eyelash growth and skin pigmentation in the inferonasal pericanthal region were observed in eye 1. The incidence of pigmentation in the inferotemporal skin region and skin hypertrichosis were similar in the two eyes. CONCLUSION: The reduction of the drop,skin contact affects the regional incidence and the extent of dermatologic skin changes that are related to bimatoprost 0.03% topical therapy