869 resultados para remoção mecânica


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Toda actividad laboral lleva implícito un riesgo inherente durante su desarrollo, y a medida aumenta este riesgo se genera mayor inseguridad, lo cual muchas veces no es percibido por los propietarios de las empresas causando una serie de problemas laborales. El problema se agudiza al descubrir que la pequeña empresa salvadoreña no cuenta con suficientes recursos para desarrollar estudios especializados que analicen la gravedad de las consecuencias que están afectando su interior, es por ello que la higiene y seguridad ocupacional deben ocupar un lugar importante dentro de la empresa. La finalidad del presente documento es aportar una herramienta práctica que ayude a identificar los riesgos que se presentan en el desarrollo de las labores que se realizan dentro de los talleres de mecánica automotriz, demostrar la gravedad de las consecuencias que pueden ocasionar en la salud de los empleados y la productividad de los mismos y al mismo tiempo permita cuantificar los beneficios derivados de la inversión en higiene y seguridad ocupacional. Mediante la investigación se determinó que la mayoría de los talleres se encuentran en condiciones físicas desfavorables para un mejor desempeño de las actividades de los trabajadores, para realizar la investigación de campo con el fin de determinar los problemas que tienen los talleres de mecánica automotriz se utilizaron fuentes primarias como; encuestas dirigidas tanto a los propietarios o encargados como a los empleados de los talleres del municipio de Soyapango, así como también se hizo uso de la observación directa; además fuentes secundarias como, libros de texto, trabajos de graduación, leyes, revistas e información de Internet. Entre algunas de las principales conclusiones que se determinaron a través de la investigación, se tuvieron: A pesar de la importancia que tiene el ambiente físico, para los propietarios este aspecto no es de gran relevancia. Como se puede apreciar gran parte de los talleres se encuentran en condiciones físicas desfavorables para un mejor desempeño. Entre las enfermedades que más afectan este sector se encuentran las relacionadas con las afecciones en las vías respiratorias, este cuadro se complica debido a las condiciones físicas existentes en los talleres y los factores derivados de las mismas. La gran mayoría de empleados cuenta con alguna medida de protección personal; sin embargo, estas no son siempre utilizadas, ya que el empleado utiliza de manera inadecuada su propio criterio para su uso, reflejo de ello son los accidentes que suceden con mayor frecuencia, entre los cuales están los golpes, cortadas y quemadas leves Con el fin de mejorar las actuales condiciones de higiene y seguridad dentro de los talleres: Se recomienda a los propietarios mejorar las condiciones físicas ambientales de los talleres. Se recomienda hacer conciencia a los empleados a cerca del uso constante del equipo de protección siempre que lo necesiten, por más sencillas que parezcan las actividades laborales a realizar; además se sugiere concentración y seriedad al momento de realizar actividades en las que puedan resultar con alguna lesión.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Metal-Ceramic (M/C) Zirconia-stainless steel interfaces have been processed through brazing techniques due to the excellent combination of properties such as high temperature stability, high corrosion resistance and good mechanical properties. However, some M/C interfaces show some defects, like porosity and cracks results in the degradation of the interfaces, leading even to its total rupture. Most of time, those defects are associated with an improper brazing parameters selection to the M/C system. In this work, ZrO2 Y-TZP and ZrO2 Mg - PSZ were joint with the stainless steel grade 304 by brazing using a eutectic silver-copper (Ag28Cu) interlayer alloy with different thermal cycles. Ceramic surfaces were previous mechanically metallized with titanium to improve adhesion of the system. The effect of temperature on the M/C interface was studied. SEM-EDS and 3 point flexural bend test were performed to evaluate morphology, chemical composition and mechanical resistance of the M/C interfaces. Lower thermal cycle temperatures produced better results of mechanical resistance, and more regular/ homogeneous reaction layers between braze alloy and metal-ceramic surfaces. Also was proved the AgCu braze alloy activation in situ by titanium

Relevância:

20.00% 20.00%

Publicador:

Resumo:

O estudo avaliou os impactos ao longo de oito anos causados pela remoção da serapilheira sobre a disponibilidade de nitrogênio e carbono orgânico no solo de uma floresta secundária na Amazônia Oriental. Na área experimental foram instaladas quatro parcelas para o tratamento de remoção da serapilheira e quatro parcelas controle (testemunha). Em cada parcela amostras de solo foram coletadas na camada de 0-10 cm para avaliação do teor de nitrogênio e carbono orgânico. Os resultados mostraram que a retirada de serapilheira impactou diretamente a disponibilização de nitrogênio e carbono orgânico no solo. Os resultados deste estudo indicam que a serapilheira presente na rizosfera de florestas secundárias na Amazônia tem papel crucial nos mecanismos de transferência de nitrogênio e carbono orgânico para o solo.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

El presente trabajo de graduación incluye un estudio en la industria metal mecánica salvadoreña fabricante de herramientas manuales de metal, en especial a una empresa como caso ilustrativo, diseñándose una estrategia de mercadeo que le permita incrementar sus niveles de venta en un mercado competitivo. El desarrollo de la investigación se realizó en el área metropolitana de San Salvador por medio de entrevistas y encuestas dirigidas a las empresas fabricantes, distribuidores y consumidores finales; considerándose como consumidores los talleres de estructuras metálicas por ser los principales demandantes de los productos fabricados por la empresa en estudio; además se obtuvo información de otras fuentes, como: Banco Central de Reserva (BCR), Fundación Salvadoreña para el Desarrollo Económico y Social (FUSADES), Cámara de Comercio de El Salvador, Dirección General de Estadísticas y Censos (DIGESTYC). El análisis de la información recopilada permitió realizar un diagnóstico de la situación competitiva de mercado en que se encuentra la industria y la empresa en particular. Así mismo, se obtuvieron datos de importancia relativos al comportamiento del consumidor y la calificación que da a los productos de la metal mecánica fabricados en El Salvador. En cuanto a la empresa en estudio se determinó que tiene demanda principalmente en los talleres de estructuras metálicas; sin embargo, no existe una lealtad firme de marca; la rivalidad es intensa; los distribuidores ejercen un alto poder de negociación en cuanto a calidad; posee un número limitado de proveedores, lo que propicia un alto poder de negociación; además, existe limitada información acerca de las herramientas que fabrica. Al reconocer la situación de la empresa, se diseña la propuesta, especificándose la misión, visión, objetivos y estrategias para cada una de las variables del mercado, orientadas de manera que se incorporen a un plan de comercialización para cinco años; además, se incluyen presupuestos para dar a conocer el efecto financiero del diseño, el plan de implementación de la propuesta; así como, el control de dicho plan y las recomendaciones respectivas.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

As most current studies, reinforced plastics have been, in recent years, a viable alternative in building structural elements of medium and large, since the lightness accompanied by high performance possible. The design of hybrid polymer composites (combination of different types of reinforcements) may enable structural applications thereof, facing the most severe service conditions. Within this class of composite materials, reinforced the underlying tissues hybrid high performance are taking space when your application requires high load bearing and high rigidity. The objective of this research work is to study the challenges in designing these fabrics bring these materials as to its mechanical characterization and fracture mechanisms involved. Some parameters associated with the process and / or form of hybridization stand out as influential factors in the final performance of the material such as the presence of anisotropy, so the fabric weave, the process of making the same, normative geometry of the specimens, among others. This sense, four laminates were developed based hybrid reinforcement fabrics involving AS4 carbon fiber, kevlar and glass 49-E as the matrix epoxy vinyl ester resin (DERAKANE 411-350). All laminates were formed each with four layers of reinforcements. Depending on the hybrid fabric, all the influencing factors mentioned above have been studied for laminates. All laminates were manufactured industrially used being the lamination process manual (hand-lay-up). All mechanical characterization and study of the mechanism of fracture (fracture mechanics) was developed for laminates subjected to uniaxial tensile test, bending in three and uniaxial compression. The analysis of fracture mechanisms were held involving the macroscopic, optical microscopy and scanning electron microscopy

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The production of water has become one of the most important wastes in the petroleum industry, specifically in the up stream segment. The treatment of this kind of effluents is complex and normally requires high costs. In this context, the electrochemical treatment emerges as an alternative methodology for treating the wastewaters. It employs electrochemical reactions to increase the capability and efficiency of the traditional chemical treatments for associated produced water. The use of electrochemical reactors can be effective with small changes in traditional treatments, generally not representing a significant additional surface area for new equipments (due to the high cost of square meter on offshore platforms) and also it can use almost the same equipments, in continuous or batch flow, without others high costs investments. Electrochemical treatment causes low environmental impact, because the process uses electrons as reagent and generates small amount of wastes. In this work, it was studied two types of electrochemical reactors: eletroflocculation and eletroflotation, with the aim of removing of Cu2+, Zn2+, phenol and BTEX mixture of produced water. In eletroflocculation, an electrical potential was applied to an aqueous solution containing NaCl. For this, it was used iron electrodes, which promote the dissolution of metal ions, generating Fe2+ and gases which, in appropriate pH, promote also clotting-flocculation reactions, removing Cu2+ and Zn2+. In eletroflotation, a carbon steel cathode and a DSA type anode (Ti/TiO2-RuO2-SnO2) were used in a NaCl solution. It was applied an electrical current, producing strong oxidant agents as Cl2 and HOCl, increasing the degradation rate of BTEX and phenol. Under different flow rates, the Zn2+ was removed by electrodeposition or by ZnOH formation, due the increasing of pH during the reaction. To better understand the electrochemical process, a statistical protocol factor (22) with central point was conducted to analyze the sensitivity of operating parameters on removing Zn2+ by eletroflotation, confirming that the current density affected the process negatively and the flow rate positively. For economical viability of these two electrochemical treatments, the energy consumption was calculated, taking in account the kWh given by ANEEL. The treatment cost obtained were quite attractive in comparison with the current treatments used in Rio Grande do Norte state. In addition, it could still be reduced for the case of using other alternative energy source such as solar, wind or gas generated directly from the Petrochemical Plant or offshore platforms

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A oportunidade de utilização do sorgo biomassa como fonte para cogeração de energia nas usinas de cana-de-açúcar, durante o período de descanso desta cultura, permitiu à Embrapa Milho e Sorgo estabelecer um trabalho integrado com a indústria de máquinas para viabilizar a produção extensiva, principalmente na colheita mecânica, com a empresa Case New Holland, de Sorocaba-SP. Este trabalho foi muito importante para resolver um dos gargalos do sistema de produção do sorgo, que vinha utilizando as colhedoras de cana-de-açúcar, com modificações no arranjo das linhas de plantio, e com baixo rendimento. A possibilidade de utilização de uma forrageira, com alta capacidade operacional, entre 140 e 160 t/ha, com o arranjo de plantas normal, sem modificações, indicava ser um grande potencial para testes com o híbrido BRS 716, que vem demonstrando excelentes produtividades de massa verde, entre 120 e 150 t/ha, em um curto período de 150 a 180 dias. Este trabalho apresenta resultados inéditos no mundo, por sermos pioneiros com a cultura do sorgo biomassa, e teve a participação da Usina Santa Vitória, em Santa Vitória-MG, da empresa Energias Renováveis do Brasil - ERB; e da Usina Rio Vermelho, em Dracena-SP, que plantaram grandes áreas para testes dos sistemas de produção, além da Embrapa Meio Ambiente, em Jaguariúna, SP, com uma área de testes, de 5 ha.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Produced water is the main effluent linked to the activity of extraction of oil and their caring management is necessary due to the large volume involved, to ensure to minimize the negative impacts of discharges of these waters in the environment. This study aimed to analyze the use of retorted shale, which is a reject from the pyrolysis of pirobituminous shale, as adsorbent for the removal of phenols in produced water. The material was characterized by different techniques (grain sized analysis, thermal analysis, BET, FRX, FT-IR, XRD and SEM), showing the heterogeneity in their composition, showing its potential for the removal of varied compounds, as well as the phenols and their derivatives. For the analysis of the efficiency of the oil shale for the adsorption process, assays of adsorption balance were carried through, and also kinetic studies and dynamics adsorption, in the ETE of the UTPF of Petrobras, in Guamaré-RN. The balance assays shown a bigger conformity with the model of Langmuir and the kinetic model more adjusted to describe the adsorption of phenols in retorted shale was of pseudo-second order. The retorted shale presented a low capacity of adsorption of phenols (1,3mg/g), when related to others conventional adsorbents, however it is enough to the removal of these composites in concentrations presented in the produced water of the UTPF of Guamaré. The assays of dynamics adsorption in field had shown that the concentration of phenol in the effluent was null until reaching its rupture (58 hours). The results showed the possibility of use of the reject for removal of phenols in the final operations of the treatment process, removing as well, satisfactorily, the color and turbidity of the produced water, with more than 90% of removal

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The acceleration of industrial growth in recent decades on all continents aroused the interest of the companies to counter the impacts produced on the environment, spurred primarily by major disasters in the petroleum industry. In this context, the water produced is responsible for the largest volume of effluent from the production and extraction of oil and natural gas. This effluent has in its composition some critical components such as inorganic salts, heavy metals (Fe, Cu, Zn, Pb, Cd, ), presence of oil and chemicals added in the various production processes. In response to impact, have been triggered by research alternative adsorbent materials for water treatment and water produced, in order to removing oils and acids and heavy metals. Many surveys of diatomaceous earth (diatomite) in Brazil involve studies on the physico-chemical, mineral deposits, extraction, processing and applications. The official estimated Jazi are around 2.5 million tonnes, the main located in the states of Bahia (44%) and Rio Grande do Norte (37,4%). Moreover, these two states appear as large offshore producers, earning a prominent role in research of adsorbents such as diatomite for treatment of water produced. Its main applications are as an agent of filtration, adsorption of oils and greases, industrial load and thermal insulator. The objective of this work was the processing and characterization of diatomite diatomaceous earth obtained from the municipality of Macaíba-RN (known locally as tabatinga) as a low cost regenerative adsorbent for removal of heavy metals in the application of water produced treatment. In this work we adopted a methodology for batch processing, practiced by small businesses located in producing regions of Brazil. The characterization was made by X-ray diffraction (XRD), scanning electron microscopy (SEM) and specific surface area (BET). Research conducted showed that the improvement process used was effective for small volume production of diatomite concentrated. The diatomite obtained was treated by calcination at temperature of 900 oC for 2 hours, with and without fluxing Na2CO3 (4%), according to optimal results in the literature. Column adsorption experiments were conducted to percolation of the in nature, calcined and calcined fluxing diatomites. Effluent was used as a saline solution containing ions of Cu, Zn, Na, Ca and Mg simulating the composition of produced waters in the state of Rio Grande do Norte, Brazil. The breakthrough curves for simultaneous removal of copper ions and zinc as a result, 84.3% for calcined diatomite and diatomite with 97.3 % for fluxing. The calcined fluxing diatomite was more efficient permeability through the bed and removal of copper and zinc ions. The fresh diatomite had trouble with the permeability through the bed under the conditions tested, compared with the other obtained diatomite. The results are presented as promising for application in the petroleum industry

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In the Hydrocarbon exploration activities, the great enigma is the location of the deposits. Great efforts are undertaken in an attempt to better identify them, locate them and at the same time, enhance cost-effectiveness relationship of extraction of oil. Seismic methods are the most widely used because they are indirect, i.e., probing the subsurface layers without invading them. Seismogram is the representation of the Earth s interior and its structures through a conveniently disposed arrangement of the data obtained by seismic reflection. A major problem in this representation is the intensity and variety of present noise in the seismogram, as the surface bearing noise that contaminates the relevant signals, and may mask the desired information, brought by waves scattered in deeper regions of the geological layers. It was developed a tool to suppress these noises based on wavelet transform 1D and 2D. The Java language program makes the separation of seismic images considering the directions (horizontal, vertical, mixed or local) and bands of wavelengths that form these images, using the Daubechies Wavelets, Auto-resolution and Tensor Product of wavelet bases. Besides, it was developed the option in a single image, using the tensor product of two-dimensional wavelets or one-wavelet tensor product by identities. In the latter case, we have the wavelet decomposition in a two dimensional signal in a single direction. This decomposition has allowed to lengthen a certain direction the two-dimensional Wavelets, correcting the effects of scales by applying Auto-resolutions. In other words, it has been improved the treatment of a seismic image using 1D wavelet and 2D wavelet at different stages of Auto-resolution. It was also implemented improvements in the display of images associated with breakdowns in each Auto-resolution, facilitating the choices of images with the signals of interest for image reconstruction without noise. The program was tested with real data and the results were good

Relevância:

20.00% 20.00%

Publicador:

Resumo:

La industria metal mecánica, aporta un porcentaje importante del producto interno bruto del país, su éxito se debe a que sirve de complemento para muchas otras industrias a quienes les soluciona problemas en su maquinaria (Automotriz, Maquila de la confección, industria de embasado, etc.). Existe un auge de esta industria pero de manera empírica y desordenada, en sus procedimientos administrativos y de control. De ahí la motivación para desarrollar un trabajo de investigación sobre un sistema de costos por órdenes específicas de producción, enfocado como herramienta financiera para obtener información eficiente y oportuna para tomar decisiones gerenciales, en las industrias de metal mecánica. El objetivo principal para la realización de este trabajo de investigación es: diseñar una guía que explique el control y registro razonable de los costos de producción. Que en forma amplia, adecuada y actualizada Explique las técnicas y procedimientos para su desarrollo e implementación; y que sirva como instrumento de apoyo a las empresas de metal mecánica a obtener información para la toma de decisiones gerenciales. La Metodología seleccionada para la investigación fue el método hipotético deductivo; que mediante la técnica de la observación permitió identificar los problemas reales siendo el principal: la falta de un sistema de costos, sus causas, efectos, y consecuencias en la industria metal mecánica. La indagación se efectuó en las empresas de metalmecánica, ubicadas en el área metropolitana de San Salvador. Al concluir quedo en evidencia que la industria metalmecánica es importante para la economía Salvadoreña, pero carecen de un sistema de información apropiado (Sistema contable y sistema de costos) que les permita obtener información eficiente y confiable para la toma de decisiones. Se les recomendó implementar un sistema contable, y un sistema de Costos por órdenes específicas que les permitan generar y obtener información oportuna y eficiente para tomar decisiones.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Los profesores de Química en la Universidad se encuentran con el problema del escaso interés que, en general, tienen los alumnos/as por esta materia, y sobre todo, los de las titulaciones de Ingeniería que se manifiesta, entre otros aspectos, en un bajo rendimiento académico. Esta falta de interés dificulta su aprendizaje significativo, provocando una adquisición mecánica de conocimientos y escasa retención. Además la Química no es una disciplina fácil. La Química es una ciencia experimental que supone el manejo de conceptos y principios de alto nivel de abstracción cuya comprensión ofrece severas dificultades a muchos estudiantes. La Química va desde un nivel microscópico (concepto de átomos, teorías atómicas, etc.) hasta la perspectiva macroscópica y simbólica (soluciones, equilibrios, etc.). Por todo ello, son numerosos los intentos para motivar al alumnado haciendo atractiva la Química mediante su acercamiento a situaciones cotidianas mostrando la importancia de la Química en nuestra sociedad, o mediante el uso de simulaciones o aplicaciones informáticas, TICs (Tecnologías de la Información y la Comunicación). La eficacia de estas experiencias va a depender de la conexión entre el fenómeno considerado, el fundamento científico del mismo y el nivel del alumno/a. Por otro lado, un ambiente de aprendizaje enriquecido con TIC juega un papel muy importante en la enseñanza de la Química, permitiendo a los estudiantes acercarse a conceptos más complejos. En este trabajo se presenta una investigación sobre el uso de los simuladores y videos sobre procesos de la vida cotidiana o profesional en los que se llevan a cabo procesos redox para favorecer el aprendizaje de las reacciones de oxidación-reducción. La investigación se ha realizado con estudiantes de la Universidad de Málaga, durante el curso 2015/16. Para estudiar el efecto del uso de las TIC sobre el proceso de aprendizaje los estudiantes de la asignatura cumplimentaron un cuestionario que consta de 10 preguntas, 8 redactadas en forma positiva y 2 en forma negativa, para evitar tendencias al responder. De los resultados obtenidos, la población estudiada considera útil el uso de la aplicación multimedia, aunque no para involucrarse en su estudio, sino para comprender la naturaleza. En líneas generales la mayoría de los alumnos/as encuestados prefiere el uso de las TICs como recurso a la enseñanza en detrimento a la lectura u otros métodos convencionales. Por ello, considera acertado su uso y, además, se muestra a favor de hacer extensivo este método en la enseñanza en otras ramas.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Dissertação (mestrado)—Universidade de Brasília, Faculdade UnB Planaltina, Mestrado em Ciências de Materias, 2016.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Civil e Ambiental, 2016.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The preparation of cement slurries for offshore well cementing involves mixing all solid components to be added to the mixing water on the platform. The aim of this work was to study the formulation of pre-prepared dry mixtures, or grouts, for offshore oilwell cementing. The addition of mineral fillers in the strength of lightweight grouts applied for depths down to 400 m under water depths of 500 m was investigated. Lightweight materials and fine aggregates were selected. For the choice of starting materials, a study of the pozzolanic activity of low-cost fillers such as porcelain tile residue, microsilica and diatomaceous earth was carried out by X-ray diffraction and mechanical strength tests. Hardened grouts containing porcelain tile residue and microsilica depicted high strength at early ages. Based on such preliminary investigation, a study of the mechanical strength of grouts with density 1.74 g/cm3 (14.5 lb/gal) cured initially at 27 °C was performed using cement, microsilica, porcelain tile residue and an anti-foaming agent. The results showed that the mixture containing 7% of porcelain tile residue and 7% of microsilica was the one with the highest compressive strength after curing for 24 hours. This composition was chosen to be studied and adapted for offshore conditions based on testes performed at 4 °C. The grout containing cement, 7% of porcelain tile residue, 7% of active silica and admixtures (CaCl2), anti-foaming and dispersant resulted satisfactory rheology and mechanical strength after curing for 24 hours of curing