Stability investigation damaged ships

There are many areas in which naval vessels could improve safety standards, although naval vessels are not necessarily regarded as less secure than the civil vessels. Although the navies never have considered water on deck a problem, it seems that this problem has a critical value in the ship damage stability analysis. As an example, this damage should be investigated if the ship has a low freeboard. For this research various studies and calculations have been carried out on several designed test vessels. It is possible to decide which criteria to use in terms of damages for each type of vessel, for example a landing ship faces more risk having grounding or raking on its bottom. This technical paper concludes with a method that helps and supports the naval architect in the analysis of damage stability. In this way, the naval engineer is able to determine which of the existing criteria fits best with the requirements of the ships function by following these few principles

Multiprocessing for the particle tracking model MODPATH

Particle tracking has several important applications for solute transport studies in aquifer systems. Travel time distribution at observation points, particle coordinates in time and streamlines are some practical results providing information of expected transport patterns and interaction with boundary conditions. However, flow model complexity and simultaneous displacement of multiple particle groups leads to rapid increase of computational requirements. MODPATH is a particle tracking engine for MODFLOW models and source code displays potential for parallel processing of particles. This article addresses the implementation of this feature with the OpenMP library. Two synthetic aquifer applications are employed for performance tests on a desktop computer with increasing number of particles. Speed up analysis shows that dynamic thread scheduling is preferable for highly heterogeneous flows, providing processing adaptivity to the presence of slow particles. In simulations writing particles position in time, thread exclusive output files lead to higher speed up factors. Results show that above a threshold number of particles, simulation runtimes become independent of flow model grid complexity and are controlled by the large number of particles, then parallel processing reduces simulation runtimes for the particle tracking model MODPATH.Peer ReviewedPostprint (published version

Análisis de las Pruebas PISA: comparación entre los sistemas educativos de Finlandia y España y las causas de la diferencia de resultados en dichas pruebas

Parece evidente que el sistema educativo español, al igual que la sociedad en general está en crisis. Las pruebas más objetivas de esta crisis en lo que al sistema educativo se refiere, son los mediocres resultados obtenidos por los alumnos en las pruebas PISA. Por el contrario, en dichas pruebas, los alumnos de Finlandia obtienen muy buenos resultados. Es llamativa esta diferencia, al tratarse de países de características parecidas (renta per cápita, pertenecía a la UE,...). El presente trabajo trata de analizar las causas de estas disparidades. Se fija como objetivos, por tanto, analizar en profundidad el sistema de evaluación PISA, parámetros que considera, muestras, tipos de pruebas, competencias que evalúa y comparar los sistemas educativos finlandés y español y las razones de los buenos resultados de uno y los no tan buenos del otro. La realización del trabajo se ha planificado siguiendo una serie de etapas que permitan aproximarse al problema planteado siguiendo un orden para después proponer una serie de soluciones. En este caso el problema son los malos resultados obtenidos por los alumnos españoles en las pruebas PISA en comparación con otros países de características similares, como Finlandia. Las soluciones a éste problema pasarán por un análisis de las pruebas en sí, un análisis del sistema educativo finlandés y las causas de sus buenos resultados y por último una serie de propuestas que siguiendo los hallazgos obtenidos en el estudio podrían hacer mejorar los resultados de los alumnos catalanes y españoles en las pruebas PISA. Los factores analizados se han agrupado en las siguientes categorías, económicos, sociales, y propios del sistema educativo. Evidentemente, no todos los factores identificados como causas de los buenos resultados de los alumnos finlandeses en las pruebas PISA son extrapolables a otros países y en este caso a España. Las circunstancias, geográficas, climáticas, económicas y socioculturales son totalmente diferentes, aunque si presenten algunas similitudes. Sin embargo hay algunos aspectos del sistema educativo finlandés que si que se podrían incorporar al español

Contactos Sociales y Orientación Estratégica: algunas implicaciones para la RSC

Las redes sociales de los directivos suelen tener un claro reflejo en las decisiones estratégicas que guían a la firma a la hora de actuar. Éstas proporcionan alternativas y ayudan a conformar los marcos de referencia que se utilizan en la toma de decisiones. Todo ello influye en el tipo de orientación estratégica de la organización y por tanto, en el nivel de responsabilidad social corporativa (RSC) que se desprende de las acciones directivas. Esto es debido a que los grupos de interés que forman parte de las mismas van a tener más probabilidades de ver cumplidas sus expectativas dependiendo del posicionamiento estratégico elegido finalmente por la empresa. Por todo esto, la propia estructura de la red que envuelve al directivo, que en este caso es estudiada desde dos de sus dimensiones, como son: la fortaleza (calidad) y la diversidad (cantidad) de los nexos que unen y conforman la red; puede condicionar definitivamente la orientación y el comportamiento estratégico y social de la organización. Cuanto mayor es el nivel de relaciones sociales, se suelen adoptar posicionamientos estratégicos más proactivos con mayor grado de desarrollo de ciertos principios de su RSC

Applying a Green Solvent with Microwave, Ultrasound, and Soxhlet Extraction Techniques to Quantify the Slip Additive Cis-1,3-docosenamide and Nine Oxidative Degradation Byproducts in Polypropylene Samples

Erucamide is used as an important slip agent for polymers. However, erucamide can degrade during processing and long-term storage, forming various oxidation products. These degra dation products can affect the recovery rates of erucamide. In this study, investigated different solid–liquid extraction methods (Soxhlet, microwave, and ultrasound) and used gas chromatography with mass spectrometry (GC-MS) to quantify erucamide and its degradation byproducts in polypropy lene (PP). A multivariable experiment was designed, and a mixed-effect approach was used to analyze the results. Various extraction variables were examined, such as temperature, time, solvents, and PP pretreatments. Using a mixed-effect model with a Kenward–Roger approximation, an R2 of the model of 97% and p values of 0.168, 0.000, and 0.000 were obtained for the technical, solvent, and type of PP pretreatment variables, respectively. The highest average recoveries of erucamide were found with the microwave technique and were 96.4% using dichloromethane, 94.57% using cyclohexane, and 93.05% using limonene. With ultrasound, recoveries ranged between 85 and 92% for dichloromethane and limonene. In addition, it was observed that the extraction method had better recovery results in ground PP than in films and in pellets. Nine oxidative degradation byproducts of erucamide were identified and semi-quantified by GC-MS. The reaction mechanisms for forming each byproduct were proposed. The byproducts that experienced a higher rate of degradation of erucamide were erucamide with a hydroxyl group at position one and 12-amino-6-12-oxo-dodecanoic acid, showing more prominent peaks using the Soxhlet method with cyclohexane and dichloromethane as solvents and polypropylene (PP) films as the type of material used.Universidad Tecnológica de Bolivar, Universidad de Cartagena, Universidad de la Cost

Designing an Advanced Regional Research Network

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Sexual Satisfaction and Mental Health in Prison Inmates

The main goal of this study was to investigate the association between sexual satisfaction and mental health, and the combined e ect of two previously found, statistically significant moderators: partner status and sexual abstinence. In-person interviews were conducted with 223 participants (49.327% males and 50.673% females). The e ect of sexual satisfaction on mental health and the interactions of sexual satisfaction partner status, sexual satisfaction sexual abstinence, and sexual satisfaction partner status sexual abstinence were examined using simple moderation and moderated moderation tests after controlling for a set of sociodemographic, penitentiary, and interpersonal variables. Results revealed a direct relationship between sexual satisfaction and mental health only for the sexually abstinent group. Partner status was not significant as a moderator. It seems that the lack of sexual relationships is more powerful as a moderator than the lack of a romantic relationship. Additionally, the sexually abstinent group showed lower levels of sexual satisfaction in those with a partner outside or inside prison, and lower mental health independently of the current romantic status, than sexually active inmates. These findings point to the importance of sexual satisfaction to mental health in sexual situations of extreme disadvantage