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/

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.

Il paesaggio sonoro campano tra contemporaneità e nuove forme di progettualità turistica

Full awareness of landscape occurs when it is holistically perceived. In other words, when there is osmosis between subject and object in terms of our observing, touching, breathing and listening to the same. Contemporaneously, the diminished attention paid to information provided by acoustic perception has had the effect of generating a propensity for looking rather than listening. The contribution intends to illustrate the soundscape of Campania through the tammurriata. It is not just one of the many forms of popular music expression, but the dance contains the focal points of a complex experience of collective participation, resulting in a significant tool for territorial knowledge, capable of promoting alternative forms of tourism and sense of community

Multiple crack propagation by DBEM in a riveted butt-joint: a simplified bidimensional approach

A Multi-Site Damage (MSD) crack growth simulation is presented, carried out by means of Dual Boundary Element Method (DBEM), in a two-dimensional analysis of a cracked butt-joint made of aluminium 2024 T3. An equivalent crack length is proposed for an approximated 2D analysis of a 3D problem where the crack front assumes a part elliptical shape due to secondary bending effects. The assumptions made to perform such simplified bidimensional analyses are validated by comparing numerical results with experimental data, the latter obtained from a fatigue tested riveted butt-joint

Residual strength evaluation by DBEM for a cracked lap joint

The present work summarizes a numerical procedure aimed at the evaluation of the residual strength of a cracked lap joint, based on the competing failure mechanisms regulated by the R-curve analysis and plastic collapse. The model adopted for Stress Intensity Factors (SIFs) evaluation is based on the use of the Dual Boundary Element Method (DBEM) within the theoretical frame of Linear Elastic Fracture Mechanics (LEFM). The value of failure load was available from experiments, allowing a comparison with numerical results and consequent validation of the described procedure

A review of acetabular prostheses for total hip arthroplasty

This study explores the evolution, design, and clinical progress of contemporary prostheses used in orthopaedic reconstruction of the socket of the hip joint. A literature search was performed to study acetabular implants, as used in total hip arthroplasty. The history of the design of these implants is chronicled. Next, the anatomy of the acetabular region and the surgical technique performed to replace the hip socket are presented. A comprehensive discussion of the design features, rationale, and clinical results for commercially available cemented and cementless prostheses follows. Hydroxyapatite, a bioceramic which has just recently been approved for applications in total hip arthroplasty, is described, the coating process explained, and its clinical effects evaluated. Finally, the abnormal or deficient acetabulum is reviewed. Corrective implants and reconstructive techniques are described

Taking the Plunge: Enhancing the Visitor Experience in Waterfall-Based State Parks

Waterfalls have long been popular tourist attractions due to their soundscape, beauty, natural pool, and recreational opportunities. With technological advances and abundant tourism information, more visitors are being drawn to waterfalls. Such high visitation and use amplifies the risk of degrading pristine waterfall sites and their resources. Not only are waterfalls experiencing high demand, but state parks are also seeing large increases in visitation. State parks are typically located closer to population centers and complement the more well-known and iconic national parks by providing recreational opportunities to more, diverse visitors. The present study aims to provide a basis for understanding the visitor experience and carrying capacity at a waterfall-based state park where visitors engage in an activity with the water (e.g., swim in the natural pool, climb the waterfall). Further, the study investigates intrasite displacement from an activity with the water in tandem with the examination of carrying capacity. Visitor surveys and time-lapse field cameras were deployed to collect data on visitor use at a popular waterfall-based state park in Tennessee. The results indicate that use levels are near or above crowding-based thresholds, supporting the implementation of a carrying capacity. While the results do not provide evidence for intrasite or activity displacement, they seem to reflect a reduction in the visitors’ freedom of choice in activity or location. The present study fills a gap in the literature by empirically investigating the carrying capacity of visitors at a waterfall site and utilizing an indicators and thresholds-based approach in a state park. Empirical research on these is needed since citizens highly value waterfalls and primarily gain exposure to nature through state park visits

Il Sistema Locale per lo Sviluppo Turistico-Creativo in Costiera Amalfitana

In recent years creativity has become a resource not only in relation to artistic and cultural activities but also in terms of economic growth and development of tourism enterprises and geographical regions. This has determined the diffusion of creative tourism based on principles of sustainability. However, debate on the issue – above all in Italy – is still ongoing as concerns definitions in line with scientific literature. Our research attempts to show that the foundations for the success of this kind of tourism lies in the consolidating of the local economy based on creativity in a systems logic. To this aim a case study on the Amalfi Coast area (Salerno) is presented providing a framework of the characteristics and creative potential in terms of tourism in order to highlight both the dynamics in act and the most significant elements for the construction of a creative ambience. Our study concludes however, that such a model cannot be considered merely a solution for all ills, but on the contrary, can be exploited only by territories that enjoy a creative humus. In other words, strategies put in place should exalt what is rooted in the geographical, social and cultural reality, i.e. as the potential base for the affirming of this new niche of cultural tourism. Otherwise, any initiatives undertaken risk becoming useless and a waste of resources.Negli ultimi anni la creatività è stata sempre più considerata una risorsa non solo in relazione alle attività artistiche e culturali, ma anche per lo sviluppo economico di imprese turistiche e di regioni geografiche, al punto da determinare la diffusione del turismo creativo, secondo i principi della sostenibilità, pure se il dibattito - soprattutto in Italia - ancora non è perfettamente definito. In sintonia con la letteratura scientifica, la presente ricerca si pone l’obiettivo di dimostrare che la condizione ineludibile per il decollo di tale forma di turismo è il consolidamento dell’economia locale basata sulla creatività, in chiave sistemica. A tal fine si presenta il caso della Costiera Amalfitana (Salerno), fornendo un quadro delle caratteristiche turistiche e delle potenzialità creative, mettendo in luce le dinamiche in atto e gli elementi più significativi per la costruzione di un’atmosfera creativa. Questo lavoro giunge a sostenere che il modello a cui si fa riferimento non può essere assunto come una “panacea”, bensì può essere implementato soltanto da quei territori che godono di humus creativi, in modo che le strategie vadano ad esaltare quanto è radicato nella realtà geografica, sociale e culturale, ossia la base potenziale per l’affermazione di questa nuova nicchia del turismo culturale. In caso contrario, qualunque iniziativa rischia di risultare un inutile dispendio di risorse