Determination of Resistance Parameters of Contaminated Compacted Tropical Soils in the State of Rio de Janeiro

Direct shear (DS) tests with controlled shear rates were performed in two soils from the Baixada Fluminense region, in the city of São João do Meriti – Rio de Janeiro, Brazil. The first soil characterized as Inorganic Clay of high plasticity (CH) was located in a hillside region. The second soil characterized as medium plasticity clay (CL) was located in a central region of the studied area with a slight slope. The soils in question are deposited on non-compacted soft soil with the addition of Municipal Solid Waste (MSW). Both samples of compacted soil were excavated at a depth of 1.0 m, and undisturbed samples were collected. In addition to the previously mentioned tests, oedometric tests and soil physical classification tests were carried out to evaluate geotechnical parameters. In both tests the shear rate of 0.043 mm / min was adopted. The tests presented coherent results with probabilistic accuracy greater than 95% inreliability compared to three tests with compacted tropical soils

External Corrosion of the bottom plate of Petroleum and Derivative Storage tanks on Compacted Soils

Inspections carried out on petroleum and derivative storage tanks on compacted soils have shown external corrosion on the bottom plates of the tanks despite cathodic protection by an impressed current. The holes or cavities in the outer plates of the bottom of the tank (in contact with the soil) result in oil leakage, thereby having significant environmental impacts. The objective of this paper is to show, in laboratory experiments, that cathodic protection is not reliable when there are voids or spaces between the plates and the soil. In addition, it proposes the application of a thermal spray with aluminium in the parts of the bottom plates that are in contact with the soil to protect these plates from localised corrosion. It is important to note that the welding temperature was 320°C, without affecting the aluminium coating applied by the thermal spray

Propargyl alcohol as a corrosion inhibitor for AISI 304L stainless steel in hydrochloric acid

Hydrochloric acid solutions (at concentrations of 5 to 28%) are used to acidify or acid-stimulate a rock-reservoir, increasing productivity of an oil well and removing calcareous deposits that lodge inside the carbon steel pipes. Typically, AISI 304 L stainless steel is used to manufacture various components, such as valves, adapters, rings, connectors, and rotors of pumps that are used in these acidifications. In order to guarantee the protection of both the carbon steel and the AISI 304 L, propargyl alcohol can be used as a corrosion inhibitor. The results of mass loss (gravimetric) and electrochemical tests (polarization curve) show a good efficiency of propargyl alcohol as a corrosion inhibitor for AISI 304 L stainless steel in concentrations of 5% (by volume) and 10% (by volume) of hydrochloric acid

A contribuição da disciplina de introdução à engenharia química no diagnóstico da evasão La contribución del curso "introducción a la ingeniería química" en el diagnostico de la evasión The contribution of introduction to chemical engineering in evasion diagnostic

Um grave problema, ainda não solucionado, que atinge os cursos de graduação em engenharia no país, são as altas taxas de evasão. Estas se devem a diversos fatores, mas em recente pesquisa realizada no curso de engenharia química da Universidade Federal Fluminense - UFF, verificou-se uma grande retenção dos alunos no ciclo básico, causada por altos índices de reprovação, que culminam em abandono. Essa grande retenção provoca também um aumento no tempo médio de permanência na universidade que na média chega a 13 semestres, quando o normal deveria ser de 10 semestres. Menos do que 20% dos alunos conseguem se formar no tempo normal. Estes dados indicam claramente um grande obstáculo a ser vencido, que prejudica a eficiência do sistema de ensino superior. Na busca por soluções, a disciplina de Introdução à Engenharia Química foi incluída no 1º período do curso de Engenharia Química, inicialmente como optativa, com o objetivo de diagnosticar e correlacionar os problemas existentes. As aulas nesta disciplina têm por base melhorar a adaptação do aluno no curso e identificar pontos de conflito. Diversas informações são passadas, sobre a universidade, o curso, a profissão, o mercado, dentre outras, buscando-se sempre motivá-los. Como resultado, verificou-se que o relacionamento professor-aluno é determinante nesta etapa do curso, resultando numa melhora global do rendimento acadêmico dos alunos.<br>La evasión en el programa de ingeniería es un tema bastante estudiado que aun no tiene solución. Estadísticas realizadas recientemente en el Departamento de Ingeniería Química de la Universidade Federal Fluminense - UFF, se observa que la mayoría de los estudiantes registrados en el curso de ingeniería se encuentran en el ciclo básico, el cual es conocido como un obstáculo difícil de pasar para muchos estudiantes, el alto índice de desaprobación es el factor mas importante para que muchos alumnos tomen la decisión de abandonar el curso. Esta grande retención en los ciclos básicos provoca un aumento en el tiempo medio de permanencia en la universidad, de 10 (tiempo normal) para 13 semestres, además de esto, menos del 20% de estudiantes logran graduarse en el tiempo normal. Todo esto indica un enorme obstáculo que daña la eficiencia del sistema de la educación superior. Observando este problema la facultad de ingeniería química da UFF implemento en el primer periodo el curso "Introducción a la Ingeniería Química", el cual tiene por objetivo diagnosticar y correlacionar estos problemas para encontrar la forma de resolverlos. Las clases de esta disciplina tienen el propósito de mejorar la adaptación del estudiante en el programa, dándoles informaciones acerca de la universidad, de los cursos de los trabajos y del mercado laboral, buscando sobre todo motivarlos. Se ha verificado que la relación entre profesores y estudiantes es muy importante en esta experiencia, que resulto en un mejor desempeño académico.<br>It has told a lot about the evasion at the engineering course, but the solution hasn't been found yet. In recent statistics accomplished at the Chemical Engineering from Universidade Federal Fluminense - UFF, it was checked out that the most of the students enrolled are the basic cycle, which becomes, at this way, a difficult obstacle to a lot of students. Several factors influences and the high index of reproval is one of those that causes a big lack of motivation among the students, specially to thoses who are on the first period, where there is the worst situation. This big retention provokes an increasing of average time of permanence in the university to 13 semesters, when the normal time is 10 semesters. Less than 20% of students are able to form in normal time. These indicates a enormous obstacle, which damaged the superior education system efficiency. The subject called Introduction to Chemical Engineering was included in the first period of the curriculum, intending to research about problem and study a way to solve it. The lessons of this subject used to have for purpose getting better the student's adaptation at the course, cooperating for his maturation. Severals informations are passed about the university, the course, the jobs, the marked, having always as an objective motivating the students. It has been verified that the relation teachers-students were very important in this experience, which resulted higher global academic performance