Vermiculitas tratadas quimicamente na obtenção de sólidos microporosos como precursores para híbridos inorgânico-orgânicos com aplicações adsortivas

ALVES, Ana paula Melo. Vermiculitas tratadas quimicamente na obtenção de sólidos microporosos como precursores para híbridos inorgânico-orgânicos com aplicações adsortivas. 2009. 124 f. Tese (Doutorado em Quimica) - Centro de Ciências Exatas e da Natureza, Universidade Federal da Paraíba, João Pessoa, PB, 2009.

Vermiculitas tratadas quimicamente na obtenção de sólidos microporosos como precursores para híbridos inorgânico-orgânicos com aplicações adsortivas

ALVES, Ana paula Melo. Vermiculitas tratadas quimicamente na obtenção de sólidos microporosos como precursores para híbridos inorgânico-orgânicos com aplicações adsortivas. 2009. 124 f. Tese (Doutorado em Quimica) - Centro de Ciências Exatas e da Natureza, Universidade Federal da Paraíba, João Pessoa, PB, 2009.

Síntese de catalisadores nanoporosos na ausência total e parcial de direcionadores orgânicos para pirólise catalítica de óleos pesados e intermediários

The processing of heavy oil produced in Brazil is an emergency action and a strategic plan to obtain self-sufficiency and economic surpluses. Seen in these terms, it is indispensable to invest in research to obtain new catalysts for obtaining light fraction of hydrocarbons from heavy fractions of petroleum. This dissertation for the degree of Doctor of Philosophy reports the materials preparation that combine the high catalytic activity of zeolites with the greater accessibility of the mesoporosity, more particularly the HZSM-5/MCM-41 hybrid, done by synthesis processes with less environmental impact than conventional ones. Innovative methodologies were developed for the synthesis of micro-mesoporous hybrid material by dual templating mechanism and from crystalline zeolitic aluminosilicate in the absence of organic template. The synthesis of hybrid with pore bimodal distribution took place from one-single organic directing agent aimed to eliminate the use of organic templates, acids of any kind or organic solvents like templating agent of crystalline zeolitic aluminosilicate together with temperature-programmed microwave-assisted, making the experimental procedures of preparation most practical and easy, with good reproducibility and low cost. The study about crystalline zeolitic aluminosilicate in the absence of organic template, especially MFI type, is based on use of H2O and Na+ cation playing a structural directing role in place of an organic template. Advanced characterization techniques such as X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Highresolution Transmission Electron Microscopy (HRTEM), Adsorption of N2 and CO2, kinetic studies by Thermogravimetric Analysis (TGA) and Pyrolysis coupled to Gas Chromatography/Mass Spectrometry (Pyrolysis-GC/MS) were employed in order to evaluate the synthesized materials. Achieve the proposed objectives, has made available a set of new methodologies for the synthesis of zeolite and hybrid micro-mesoporous material, these suitable for catalytic pyrolysis of heavy oils aimed at producing light fraction

Plásticos reforçados a base de tecidos híbridos: efeitos da anisotropia e geometria normativa na caracterização mecânica e da fratura

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

Design gráfico da pluma de contaminação por compostos orgânicos voláteiss utilizando software CAD na investigação de passivo ambiental em um posto revendedor de combustíveis em Natal/RN

Among the potentially polluting economic activities that compromise the quality of groundwater are the gas stations. The city of Natal has about 120 gas stations, of which only has an environmental license for operation. Discontinuities in the offices were notified by the Public Ministry of Rio Grande do Norte to carry out the environmental adaptations, among which is the investigation of environmental liabilities. The preliminary and confirmatory stages of this investigation consisted in the evaluation of soil gas surveys with two confirmatory chemical analysis of BTEX, PAH and TPH. To get a good evaluation and interpretation of results obtained in the field, it became necessary three-dimensional representation of them. We used a CAD software to graph the equipment installed in a retail service station fuel in Natal, as well as the plumes of contamination by volatile organic compounds. The tool was concluded that contamination is not located in the current system of underground storage of fuel development, but reflects the historical past in which tanks were removed not tight gasoline and diesel

A influência do marketing ambiental na decisão de compra dos consumidores de produtos orgânicos

The search of the man for more comfort and one better quality of life led to an increment of the production of goods and services, that results, almost always, in aggressions to the nature and to a reduction of this same quality of life. The concern with the ambient problems appears as an important element regarding the material and economic growth and of the quality of life. With this scene a new question, the Ambient Marketing appears. Although the marketing concept to be well ample, the companies use the term ambient marketing to make reference what in fact, many times, are a more specific activity of ambient communication. The ambient communication is a new form to communicate used for the companies with the objective to get advantages of its competitors ahead, since the competitiveness by means of the o price, the stated period and the quality if becomes extremely incited. In view of the current competitive market, where the organizations need distinguishing to get greater have detached front to the competition, and the fact of the society to be each time more worried about the environment and the impacts that the companies cause it, the ambient communication has been used as form to convince its customers. Of this form, she evaluated herself, through a exploratory research and qualitative, the influence of the use of the ambient communication in the decision of purchase and of that she forms the companies when using of this communication can add value to its product. The results had indicated that 77% of the interviewed ones had heard to say on marketing or ambient communication and that the television is main the media for this knowledge, a time that 90.9% of the respondents had affirmed to have seen propagandas of directed products of consumption to the ambient question in this way. In fact, the concern with the environment demonstrated for the companies has its impact, therefore 84% of the respondents had told if to sensetize with this fact. However, only a lesser number of people, 70.5% answered that this concern really influences in its decision of purchase

Fatores que afetam o interesse de compra de produtos orgânicos em supermercados de Manaus/AM

Demand for organic foods in the Brazil are growing year last, characterizing itself for if constituting in a new strategical segment of commercialization. In this context, the objective of this research was to investigate the factor that influence the interest of the consumers in the purchase decision of organic products, aiming to characterize the level of competitiveness of these products, assisting in the creation of environmental strategies for the development of the activity and contributing in the increment of the knowledge about the subject, that can assist it in the increase of the commercialization and the consumption of these foods. From data collected in the city of Manaus/AM, it was used a survey research, of exploratory and descriptive character. The sample was obtained using 421 questionnaires, in which was realized the descriptive analysis, analysis of groupings and association analysis among variables using the test qui-square. The results found in this study indicate that the majority the of consumers of supermarkets of the Manaus/AM never to purchase organic foods. Generally the consumers to have few or some knowledge about these foods, however, the level of the interest in to obtain information about the subject is high.The barriers mains in the purchase of organic products are the label fault in the product and the quality no certificate in the product. Among the profile characteristics, the variables income and level scholar are associate to interest level in the obtain information about the subject

Estratégia de marketing ambiental no varejo de alimentos: um estudo sobre as variáveis utilizadas pelo consumidor na decisão de compra de produtos orgânicos

Demand for organic foods within in Brazil are growing, characterizing itself for if constituting in a new strategical segment of commercialization. In this context, the objective of this research was to investigate the variables used by consumers in the purchase decision of organic products, aiming to characterize the level of competitiveness of these products, assisting in the creation of environmental strategies for the development of the activity and contributing in the increment of the knowledge about the subject, that can assist it in the increase of the commercialization and the consumption of these foods. From data collected in the city of Natal/RN, it was used a survey research, of exploratory and descriptive character. The sample was obtained using 401 questionnaires, in which was realized: the Test of Comparison of Averages, Descriptive analysis, analysis of Cluster and Qui-square. The results found in this study indicate that the main reasons for the organic food purchase are the absence of chemical pesticides in the product, followed by the care with own health and of the household. The main characteristics in the consumers of supermarkets, that are associates with purchase frequency of organic foods are the environmental behavior and lifestyle. Among the profile characteristics, gender, age and number of children are associates with the purchase frequency of these foods and the income and level education not showed association

Gestão ambiental e competitividade: um estudo sobre os fatores que afetam a decisão de compra de produtos orgânicos na cidade de Teresina-PI

The organic products represent one of the main trends of alimentary consumption in the new century. In Brazil, the answer is already well representative which it becomes the country, as a great consuming and exporting market of products of LVF type. The objective of this research was to investigate the factors capable to influence the food consumer in its purchase decision of organic products in the supermarkets of Teresina, capital of Piauí State. The methodology was exploratory and descriptive, using survey, with closed and opened questions in 542 interviewed. The questionnaire was based on projected scales to evaluate the factors that can influence the purchase decision of organic products, whose variable had been grouped in the following groups: behavior, knowledge, interest, competitiveness, importance, barrier and profile. The used statistical techniques were descriptive analysis and multiple regression analysis. The results demonstrate interest of the population in paying more for the organic product, due to better quality of life, however it lacks to one better spreading and greater sensitization to attract these consumers. Some recommendations and proposals are presented after the results, as suggestions for future research

Compósitos híbridos: desenvolvimento de configuração e efeitos de umidificação

The advantage in using vegetable fibres in place of synthetic fibres such as glass fibre, for reinforcements in composites are: biodegradability, low cost, low density, good tenacity, good thermal properties, low energy content and reduced use of instruments for its treatment or processing. Even though, problems related to low mechanical performance of some of the natural fibres, has caused difficulty in their direct application in structural elements. The use of alternative materials like hybrid composites has been encouraged, thus trying to better the structural performance of the composites with natural fibres. This work presents a comparative study of the strength and stiffness of hybrid composites with orthopthalic polyester matrix reinforced with E-fibre glass, jute and curauá. The experimental part includes uniaxial tension and three point bending tests to determine the mechanical properties of the final product. The hybrid composite was manufactured in a local industry and was in the form of laminates. All the samples were projected to withstand the possible structural applications as reservoirs and pipes. CH (laminated hybrid composite with glass and curauá fibres). The results obtained show clearly the influence of the hybridization in all the types tested and indicate a good mechanical performance of the composite with glass/curauá fibres in relation to the composite with glass fibres. Aspects in relation to the interfaces glass/curauá composites besides the fracture characteristics for all loading types were also analysed

Envelhecimento ambiental acelerado em PRF a base de tecidos híbridos kevlar/vidro: propriedades e instabilidade estrutural

There are a number of damaging mechanisms that various materials can suffer in service. However, when working with polymer composite materials, this is something that requires analysis, especially when exposed to adverse environmental conditions. Thus, the objective of the present thesis is the study of the direct influence of environmental aging and the form of hybridization of the reinforcement woven on the structural stability, surfacedegradation and fracture process of polymer composites laminates. For this, the development of two polymer composite laminates was necessary, where one of them was reinforced with a bi-directional woven with hybrid strandsofkevlar-49/glass-Efibers, and the other also with a bi-directionalwoven, however with weft and warpformed of alternating strandsof Kevlar-49 fibers and glass-E fiber The reinforcementwoven are industrially manufactured. Both laminates use a polyester resin as a matrixand are made up of four layers each. All laminates were industrially prepared by the hand lay-up method of manufacturing. To do this, test specimens were manufactured of the respective laminates and submitted to environmental aging accelerated through the aging chamber. They were exposed to alternating cycles of UV radiation and moisture (heated steam) for a standard defined period. At the end of the exposure period the specimens were subjected to mechanical tests of uniaxial tensile and bending in three points and to the characterizationsof the fracture and surface deterioration. In addition, they were submitted to a structural degradation assessment by the measurement of mass variation technique (MMVT) and the measurement of thickness variation technique (MTVT), this last technique being developed in this thesis. At the end of the analysis it was observed that the form of hybridization of the reinforcement woven and the aging process directly influence with losses or gain in mechanical properties, with losses in the structural degradation and in the formation and propagation of damage mechanism of the developedcomposite laminates

Desempenho mecânico de compósitos híbridos de fibras naturais e poliéster não saturado

With the objective to promote sustainable development, the fibres found in nature in abundance, which are biodegradable, of low cost in comparison to synthetic fibres are being used in the manufacture of composites. The mechanical behavior of the curauá and pineapple leaf fibre (PALF) composites in different proportions, 25% x 75% (P1), 50% x 50% (P2) e 75% x 25% (P3) were respectively studied, being initially treated with a 2% aqueous solution of sodium hydroxide. Mechanical analyses indicated that with respect to studies of traction, for the combination of P1 and P3, better results of 22.17 MPa and 16.98 MPa, were obtained respectively, which are higher than that of the combination P2. The results of the same pattern were obtained for analysis of bending resistance where P1 is 1.21% and P3 represents 0.96%. In the case of resistance to bending, best results were obtained for the combination P1 at 49.07 MPa. However, when Young's modulus values were calculated, the values were different to the pattern of the results of other tests, where the combination P2 with the value of 4.06 GPa is greater than the other combinations. This shows that the PALF had a greater influence in relation to curauá fibre. The analysis of the results generally shows that in combinations of two vegetable fibers of cellulosic origin, the fiber which shows higher percentage (75%) is the best option than to the composition of 50%/50%. In the meantime, according to the results obtained in this study, in the case where the application should withstand bending loads, the better composition would be 50%/50%

Estudo da presença de entalhes semicirculares em compósitos poliméricos híbridos

Composite materials have a wide application in various sectors, such as the medical field in the manufacture of prostheses, in automotive and aerospace. Thus it is essential to the development of new composite and a better understanding in the face of various loading conditions and service. Several structural elements are manufactured in the presence of geometric discontinuity (notch, hole, etc ) in their longitudinal sections and/or cross-cutting, and these affect the mechanical response of these elements. The objective is to study the mechanical response of laminated polymer matrix hybrid composites reinforced with glass fiber/jute in a uniaxial tensile test. The mechanical response takes in account both the influence of the presence of a geometric discontinuity (semicircular notches) and the orientation of fibers in the layers (anisotropy). The semicircular notches are located in longitudinal section (with a reduction in cross section) of the same. In this analysis, the anisotropy is characterized by types of configurations (with different orientations of fibers in the outer layers). A comparative study of mechanical properties with and without the presence of notches is developed. Both configurations consist of four layers of woven jute fiber bidirectional and a central layer of bidirectional woven glass fibers. In addition to the mechanical properties was also studied the characteristics of the fracture developed in each composite laminate. The results showed that in the comparative study, the anisotropy and the presence of semicircular notches directly influences the mechanical behavior of laminates composites, mainly in reducing the tensile strength, and well as the final characteristics of the fracture

Influência da umidade nas propriedades mecânicas dos compósitos poliméricos híbridos (sisal/ vidro)

This study aims to evaluate the mechanical properties of polymer matrix composites reinforced with sisal fabric bidirectional tissue (Agave sisalana,) and E-glass fibers, containing the following configuration: a polymer matrix hybrid composite (Polyester Resin orthophalic) reinforced with three (3) layers of glass fibers and alternating-2 (two) layers of bidirectional sisal fabric, and finally a composite of polymer matrix reinforced with five (5) layers of glass fiber mat-type E. For this purpose as first step, the preparation of by sisal, since they are not on the market. The composites were made by manual lamination (Hand lay-up) and evaluated for tensile properties and three point bending both in the dry, and wet conditions aswele as immersed in oil. Macroscopic and microscopic characteristics of the materialsweve awalysed, after the completion of the mechanical tests. After the studies, it was proven that the sisal fiber decreases the tensile stiffness of the material above 50% for both situations studied the tensile strength of the material decreases by approximately 40% for the cases mentioned, and when compared to the specific strength stiffness values drop to 14.6% and 29.02% respectively for the dry state only. Constants for bending the values were are to approximately 50% to 25% for strength and stiffness of the material for the cases dry, wet and immersed in oil. Under the influence of tension fluids do not interfere in the stiffness of the material for the bending tests, the same does not occur with the resistance, and these values are modified only in the cases stiffness and flexural strength

Envelhecimento ambiental em compósitos poliméricos à base de tecidos de reforços híbridos

The utilization of synthetic fibers for plastic reinforcement is more and more frequent and this growing interest requires that their mechanic behavior under the most variable conditions of structural applications be known. The use of such materials in the open and exposed to the elements is one of them. In this case, it becomes extremely necessary to study their mechanical properties (strength, stiffness) and the mechanism of fracture by which the environment aging them out. In order to do that, the material must be submitted to hot steam and ultraviolet radiation exposure cycles, according to periods of time determined by the norms. This study proposal deals with the investigation of accelerated environmental aging in two laminated polymeric composites reinforced by hybrid woven made up of synthetic fibers. The configurations of the laminated composites are defined as: one laminate reinforced with hybrid woven of glass fibers/E and Kevlar fibers/49 (LHVK) and the other laminate is reinforced with hybrid tissue of glass fibers/E and of carbon fibers AS4 (LHVC). The woven are plane and bidirectional. Both laminates are impregnated with a thermofix resin called Derakane 470-300 Epoxy Vinyl-Ester and they form a total of four layers. The laminates were industrially manufactured and were made through the process of hand-lay-up. Comparative analyses were carried out between their mechanical properties by submitting specimen to uniaxial loading tractions and three-point flexion. The specimen were tested both from their original state, that is, without being environmentally aging out, and after environmental aging. This last state was reached by using the environmental aging chamber