On the Geometrical Non-Linearities of the Ship Load Expressions

In the structural analysis a fundamental rule is played by the internal forces and moments: they are the only variables on which the study for the primary level of the ship structural response is based, in accordance with beam theory. First of all, based on the usual decomposition of loads general expressions for the distributed still water, inertial and restoring loads have been revisited. Additionally, the influence of the non-linearity arising from the hull geometry on loads has been studied. Particular attention has been also given to the evaluation of loads due to the dynamic pressure in wave. Finally, two numerical examples have been carried out in order to verify the aforementioned influence on loads. The results obtained have been particularly discussed

Fuel saving and reduction of emissions in ports with cold ironing applications

The progress of economic globalization, the rapid growth of international trade and maritime transportation have played a significant role in providing international cargo and passenger transportation. Seaports all over the world are suffering from the problem of fuel consumption and exhaust gases coming by ships during their stopover in ports. In Italy, the emissions of the industrial and energy sectors have been reduced (almost 50% between 1998 and 2012), but the sulfur oxide (SOx ) from the maritime sector has almost doubled. The national and international maritime traffic is responsible for 80% of total emissions attributable to transportation. In this paper firstly we propose a method to compare the costs of various shore-side power sources connections with those obtained by use of auxiliary engines on board; two numerical examples have been developed. The results, in terms of costs and reduction of exhaust, have been particularly discussed

Ship stability in wave: a proposal method for dynamic behaviour evaluation

Recent IMO activities are addressed to a renewal process about Intact Stability code. The new generation of stability criteria should be developed in order to be as close as possible to the real physics. The aim of this research work is to develop and validate a tool, intended for displacement vessels, capable to evaluate the ship response to wave actions and its effect on stability

Evaluation of the environmental impact of harbour activities: problem analisys and possible solutions

A relevant problem is a main subject of this work: the pollution in ports close to inhabited zones where, due to the contemporaneous presence of many cruise ships, the contents of noxious elements in the air are excessive and the quality of life risks to become unsustainable. The impact of the operations of cruise ships in port has been analysed together with the possible consequences of their impact on the human health and the rules that attempt to reduce the effects of the pollution on it. Some possible solutions were proposed; first of all, the so called “cold ironing” consisting in a connection between the electric system of the ship and a shore system providing the ship with the electric energy to be used onboard. The major characteristics of the cold ironing were analysed together with its main problems; among them, the need of integrate this practice in a more wide scene, combining it with the microgrids in order to not to solve the problem simply by moving the production of electric energy from one site to another

CARATTERIZZAZIONE ACUSTICA DI NAVI IN PORTO

Le sorgenti acustiche portuali sono molte e variegate: tra queste, le navi occupano un posto di primo piano. La caratterizzazione della sorgente nave non è molto trattata in letteratura e presenta aspetti problematici legati alle dimensioni del mezzo ed alla sua complessità impiantistica. Il testo riporta i risultati di una campagna sperimentale condotta nel porto di Napoli su diversi tipi di imbarcazione in condizioni transitorie e stazionarie. L’attività è propedeutica alla formulazione di un modello di propagazione verso le zone abitate che circondano il porto

A sustainable electrical interface to mitigate emissions due to power supply in ports

The paper presents a proposal of an innovative sustainable power supply solution for seaports with the related design and control. This solution differs from the classical solution for the presence of a smart electrical interface composed by two basic components: the first one, a rotating converter instead of the widely used static converter that ensures higher and therefore much more detectable short-circuit currents; the second, an advanced static var compensator specifically designed for enhancing power quality issues and hence favoring these seaport connection to the main grid for cold ironing applications. The designed control strategy for the tailored power supply solution is proven successful and effective by the numerical applications reported in the last part of the paper

Chronic HBV infection in pregnant immigrants: a multicenter study of the Italian Society of Infectious and Tropical Diseases

The aims of the study were to estimate the clinical impact of HBV infection in pregnant immigrants and their family members and to identify a useful approach to managing the healthcare of HBsAg-positive immigrants. Included in this study were 143 HBsAg-positive pregnant immigrants of the 1,970 from countries with intermediate/high HBV endemicity who delivered in 8 Italian hospitals in 2012-2013. In addition, 172 family members of 96 HBsAg-positive pregnant immigrants were tested for serum HBsAg. The median age of the 143 HBsAg-positive pregnant immigrants was 31.0±12.1 years and the length of stay in Italy 5.0±4.1 years; 56.5% were unaware of their HBsAg positivity. HBV DNA was detected in 74.5% of the pregnant immigrants, i.e., 94.3% from Eastern Europe, 72.2% from East Asia and 58.1% from Sub-Saharan Africa. HBV DNA ≥2000 IU/mL was detected in 47.8% of pregnant immigrants, associated with ALT ≥1.5 times the upper normal value in 15% of cases. Anti-HDV was detected in 10% of cases. HBsAg was detected in 31.3% of the 172 family members. All HBsAg-positive immigrants received counseling on HBV infection and its prevention, and underwent a complete clinical evaluation. The findings validate the approach used for the healthcare management of the HBsAg-positive immigrant population

Alternative binders as milestone of 3R strategy for sustainable construction materials

The main challenge for concrete industry - and in general for construction materials - is to serve the two major needs of human society, the protection of the environment, on one hand, and the requirements of buildings and infrastructures by the world’s growing population, on the other. In the past concrete industry has satisfied these needs well. However, for a variety of reasons, the situation has changed dramatically in the last years. First of all, the concrete industry is the largest consumer of natural resources. Secondly, Portland cement, the binder of modern concrete mixtures, is not as environmentally friendly. The world's cement production, in fact, contributes to the earth's atmosphere about 7% of the total CO2 emissions, CO2 being one of the primary greenhouse gas (GHG) responsible for global warming and climate change. As a consequence, concrete industry in the future has to face two antithetically needs. In other words, how the concrete industry can feed the growing population needs being - at the same time - sustainable? The answer to this question is represented by the “3R-Green Strategy” widely discussed in the first chapter of this PhD thesis: Reduction in consumption of gross energy for construction materials production, Reduction in polluting emissions and Reduction in consuming not renewable natural resources. In particular, this thesis is focused on the alternative binders to Portland cement such as alkali-activated slag cements and calcium sulphoaluminate cement-based binders in order to manufacture sustainable mixtures for special applications such as repair mortars, lightweight reinforced plasters and concretes for slabs on ground. The experimental results show the feasibility of manufacturing both EN 1504-3 R3 class mortars and Portland-free concretes for jointless slabs on ground with calcium sulphoaluminate cement, supplementary cementitious materials (fly ash, ground granulated blast furnace slag) and hydrated lime instead of Portland cement. Moreover, alkali-activated mortars and concretes seem to be a reasonable alternative to natural hydraulic lime-based and/or traditional Portland cement-based mixtures for rehabilitation or restoration of ancient masonry buildings and existing concretes structures. Finally, a new sustainability index was developed taking into account the environmental impact, the performances and the durability of mixtures. In particular, in the environmental impact section, the natural raw materials consumption, the greenhouse gas emissions and the energy consumption have been considered. Furthermore, depending on the applications and the environments, design parameters and properties related to durability have been assigned to each mixture

Poster: Kotlin Assimilating the Android Ecosystem - An Appraisal of Diffusion and Impact on Maintainability

Kotlin is a language alternative to Java, introduced in 2011. It promises to address many of Java's limitations and lead to better application maintainability. In 2017, it became a first-class language for Android development with full tool support. We mined a dataset of 2708 Android applications on which we based our study. Our empirical assessment of the diffusion of Kotlin in Android app development shows that it is now used in around 40% of projects. Kotlin adoption has a significant positive effect on code maintainability metrics and in popularity among end-users and developers. Overall, Kotlin appears to be successfully fulfilling its promise of being a better Java for Android development

Know Your Bugs: A Survey of Issues in Automated Game Testing Literature

As the complexity of video games continues to evolve, so does the importance of effective game testing methodologies. To this end, automated game testing has emerged as a pivotal approach to ensure the quality and functionality of modern games. The objective of the present paper is to identify, through a literature review and the application of Open and Axial coding, the most commonly analysed and mentioned issues in automated game testing literature. The results of the study provide a taxonomy of 26 different issues that are assessed in the software engineering literature by automated game testing practice, grouped in five higher-level categories. The elicited taxonomy can serve as an instrument for game testers, researchers and tool developers to evaluate testing approaches and techniques, enable comparability of research results, and design instruments to investigate functional aspects of games in development