Corrosion Protection Systems in Offshore Structures

Corrosion plays a pivotal role in the engineering world. Engineers of all disciplines must consider the dangers that this phenomenon can incur. Interestingly, corrosion mitigation is not a topic that is addressed in most academic curricula. The goal of this paper is to give engineering students a brief introduction into corrosion and some of the prevention techniques commonly used today. The design of a corrosion protection system for offshore structures is discussed in order to illustrate how these techniques can be utilized even in the most extreme environments. First, the driving force behind corrosion is examined, introducing the basic mechanics that fuel this phenomenon. Some of the most common types of corrosion experienced by structures are discussed to make engineers aware of what to expect in the field. Next, the most widely used corrosion mitigation techniques such as coatings and cathodic protection are addressed. Utilizing currently recommended industry practice, an in-depth discussion of the process of designing a cathodic protection system for offshore structures is studied. Finally, this procedure is demonstrated by applying the design process to an existing offshore structure

Stochastic processes of the urn type with convergent predictive distributions

In this work we propose a general class of stochastic processes with random reinforcement that are extensions of the celebrated Pòlya sequence by Blackwell and MacQueen [Ann. Stat. 1 (1973) 353--355]. The resulting randomly reinforced Pòlya sequences (RRPS) can be described as urn schemes with countable number of colors and general replacement rules. Under assumptions of conditional independence between reinforcement and observation, a RRPS becomes conditionally identically distributed (in the sense of [Ann. Probab. 32 (2004) 2029--2052]), and thus predictively convergent, in which case we show that it is asymptotically equivalent in law to an exchangeable species sampling sequence. This result has important implications on the generated random partition, which can be visualized as a weighted version of the Chinese Restaurant Process. We then provide complete distributional characterization of the predictive limit for the model with dichotomous reinforcements. Throughout the second part of the thesis, we consider an alternative specification of the replacement mechanism of a RRPS, whereby we deem some colors to be probabilistically dominant. In this situation the predictive and empirical distributions evaluated near the set of dominant colors both tend to 1. In fact, under some further restrictions on the reinforcement, the predictive and empirical distributions converge in the sense of almost sure weak convergence to one and the same random probability measure, whose mass is concentrated on the dominant set. As a consequence, the process becomes asymptotically exchangeable and its law -- directed by the above random measure, so that the data structure gets relatively sparse with time. The predictive limit for both models is generally unknown, however, so we derive central limit results, with which to approximate its distribution. The last chapter of the thesis is addressed towards applications of the RRPS, with the dominant-color model being considered in the context of clinical trials with response-adaptive design. Sections discussing uni- and multivariate extensions of the RRPS complete our study

Testbed Emulator of Satellite-to-Ground FSO Downlink Affected by Atmospheric Seeing Including Scintillations and Clouds

Free Space Optics (FSO) technology enabling next-generation near-Earth communication is prone to severe propagation losses due to atmospheric-turbulence-induced fading and Mie scattering (clouds). As an alternative to the real-time evaluation of the weather effects over optical signal, a state-of-the-art laboratory testbed for verification of slant APD-based (Avalanche Photodiode) FSO links in laboratory conditions is proposed. In particular, a hardware channel emulator representing an FSO channel by means of fiber-coupled Variable Optical Attenuator (VOA) controlled by driver board and software is utilized. While atmospheric scintillation data are generated based on Radiosonde Observation (RAOB) databases combined with a statistical design approach, cloud attenuation is introduced using Mie theory together with empirical Log-Normal modeling. The estimation of atmospheric-turbulence-induced losses within the emulated optical downlink is done with an FSO IM/DD prototype (Intensity Modulation/Direct Detection) relying on two different data throughputs using a transmitter with external and internal modulation. Moreover, the receiver under-test is a high-speed 10 Gbps APD photodetector with integrated Transimpedance Amplifier (TIA) typically installed in OGSs (Optical Ground Stations) for LEO/GEO satellite communication. The overall testbed performance is addressed by a BER tester and a digital oscilloscope, providing BER graphs and eye diagrams that prove the applied approach for testing APD-TIA in the presence of weather-based disruptions. Furthermore, the testbed benefits from the used beam camera that measures the quality of the generated FSO beam

Bomberman modo multijugador

Este trabajo presenta el proyecto Bomberman, realizado en la asignatura Sistemas Empotrados Distribuidos, perteneciente a la titulación del Máster en Ingeniería Informática de la Universidad Complutense de Madrid. En este trabajo se describe e implementa una adaptación del conocido juego Bomberman en modo multijugador (dos jugadores). En esta versión los dos jugadores tratarán de salir de un laberinto o derrotar a su contrincante para ganar. Este proyecto utiliza dos placas de desarrollo S3CEV40 representado a cada jugador, una Raspberry Pi 2, dos cables hembra-hembra de 9 pines y dos adaptadores a 9 pines-USB para conectar cada cable desde cada placa S3CEV40 a la Raspberry.This paper presents the Bomberman project, carried out in the Distributed Embedded Systems subject, which belongs to the Computer Science Master that is taught at the Complutense University of Madrid. This work describes and implements an adaptation of the well-known Bomberman game in multiplayer mode (for two players). In this version, the two players will try to escape from a labyrinth or to destroy his opponent to win. This project use two S3CEV40 boards to represent the players, a Raspberry Pi 2, two female-to-female 9 pin cables and two 9 pins-to-USB adapters to connect each board to the Raspberry.Universidad de Granada: Departamento de Arquitectura y Tecnología de Computadores; Vicerrectorado para la Garantía de la Calidad

Colorectal resections - clinical and immunological results

INTRODUCTION: Surgery induces a generalized state of postoperative immunosuppression responsible for a lot of complications in postoperative period. Magnitude and type of the intraoperative injury depend on the extent and duration of postoperative immune suppression. This study compared clinical outcomes and immune changes after minimally invasive and open colorectal resections in patients with colorectal cancer (CRC).MATERIAL AND METHODS: Study included 40 patients with CRC who underwent colorectal resections in our clinic last year. Twenty one of them underwent minimally invasive surgery, with a mean age of 64.8 years (49-86). The rest 19 patients underwent conventional surgery, with a mean age of 66.2 years (56-84). Blood tests were performed 24 hours prior to surgery, 24 hours and 7 days after surgery. Analysis included full blood count, total protein, albumin and markers of inflammation (CRP, ESR, fibrinogen). T- (CD3+), B- (CD19+) and NK-cell lymphocyte populations were studied by means of flow cytometry, as well as activation of leucocytes, according to the expression of HLA-DR, CD38, CD279, CD163 and some clinical parameters. All data were analyzed using SPSS version 21.RESULTS: There was no significant difference in preoperative results between minimally invasive group and conventional group. At 24 hours after surgery there were significant decrease in lymphocyte percentages and increased leucocyte count, granulocyte percentages and CRP levels in conventional group. This ratio maintained at 7 days after surgery. Activated monocyte (CD 163+), total protein and albumin, eosinophiles, percentage of monocytes, lymphocytes and NKT-cells (CD3+ CD16/CD56+) were significant decrease in conventional group compared with minimally invasive group at first postoperative day.CONCLUSIONS: Minimally invasive colorectal cancer resection is a technically feasible option, with comparable results in terms of oncologic clearance, lesser degrees of tissue injury, surgical metabolic stress, and immunosuppressive response to conventional open surgery. Patients undergoing minimally invasive resections demonstrated improved clinical recovery and shorter hospital stay than patients undergoing open surgery. 

Who Smokes in Europe? Data From Twelve European Countries in the TackSHS Survey (2017-2018)

Background: Population data on tobacco use and its determinants require continuous monitoring and careful inter-country comparison. We aimed to provide the most up-to-date estimates on tobacco smoking from a large cross-sectional survey, conducted in selected European countries. Methods: Within the TackSHS Project, a face-to-face survey on smoking was conducted in 2017–2018 in 12 countries: Bulgaria, England, France, Germany, Greece, Ireland, Italy, Latvia, Poland, Portugal, Romania, and Spain, representing around 80% of the 432 million European Union (EU) adult population. In each country, a representative sample of around 1,000 subjects aged 15 years and older was interviewed, for a total of 11,902 participants. Results: Overall, 25.9% of participants were current smokers (31.0% of men and 21.2% of women, P \u3c 0.001), while 16.5% were former smokers. Smoking prevalence ranged from 18.9% in Italy to 37.0% in Bulgaria. It decreased with increasing age (compared to Conclusions: These smoking prevalence estimates represent the most up-to-date evidence in Europe. From them, it can be derived that there are more than 112 million current smokers in the EU-28. Lower socio-economic status is a major determinant of smoking habit in both sexes

Who smokes in Europe? Data from 12 European countries in the TackSHS survey (2017-2018)

Background: Population data on tobacco use and its determinants require continuous monitoring and careful inter-country comparison. We aimed to provide the most up-to-date estimates on tobacco smoking from a large cross-sectional survey, conducted in selected European countries. Methods: Within the TackSHS Project, a face-to-face survey on smoking was conducted in 2017-2018 in 12 countries: Bulgaria, England, France, Germany, Greece, Ireland, Italy, Latvia, Poland, Portugal, Romania, and Spain, representing around 80% of the 432 million European Union (EU) adult population. In each country, a representative sample of around 1,000 subjects aged 15 years and older was interviewed, for a total of 11,902 participants. Results: Overall, 25.9% of participants were current smokers (31.0% of men and 21.2% of women, P < 0.001), while 16.5% were former smokers. Smoking prevalence ranged from 18.9% in Italy to 37.0% in Bulgaria. It decreased with increasing age (compared to <45, multivariable odds ratio [OR] for ≥65 year, 0.31; 95% confidence interval [CI], 0.27-0.36), level of education (OR for low vs high, 1.32; 95% CI, 1.17-1.48) and self-rated household economic level (OR for low vs high, 2.05; 95% CI, 1.74-2.42). The same patterns were found in both sexes. Conclusions: These smoking prevalence estimates represent the most up-to-date evidence in Europe. From them, it can be derived that there are more than 112 million current smokers in the EU-28. Lower socio-economic status is a major determinant of smoking habit in both sexes