164 resultados para Reuso


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Chemical modification of polymer matrices is an alternative way to change its surface properties. The introduction of sulfonic acid groups in polymer matrices alter properties such as adhesion, wettability, biocampatibility, catalytic activity, among others. This paper describes the preparation of polymeric solid acid based on the chemical modification of poly (1-fenietileno) (PS) and Poly (1-chloroethylene) (PVC) by the introduction of sulfonic acid groups and the application of these polymers as catalysts in the esterification reaction of oleic acid with methanol. The modified materials were characterized by Infrared Spectroscopy, Elemental Analysis and titration acid-base of the acid groups. All techniques confirmed the chemical changes and the presence of sulfur associated with sulfonic acid groups or sulfates. The modified polymers excellent performance in the esterification reaction of oleic acid with methanol a degree of conversion higher than 90% for all investigated polymers (modified PS and PVC (5% w / w)), with a mass ratio of oleic acid: methanol 1:10 to 100 ° C. The best performance was observed for the modified PVC catalyst (PVCS) which showed low degree of swelling during the reactions is recovered by filtration different from that observed for polystyrene sulfonate (PSS). Given these facts, the PVCS was employed as a catalyst in the esterification reaction of oleic acid in different times and different temperatures to obtain the kinetic parameters of the reaction. Experimental data show a great fit for pseudo-homogeneous model of second order and activation energy value of 41.12 kJ mol -1, below that found in the literature for the uncatalyzed reaction, 68.65 kJ mol -1 .The PVCS exhibits good catalytic activity for 3 times of reuse, with a slight decrease in the third cycle, but with a conversion of about 78%. The results show that solid polymeric acid has good chemical stability for the application in esterification reaction of commercial importance with possible application in the biodiesel production. The advantages in use of this system are the increased reaction rate at about 150 times, at these test conditions, the replacement of sulfuric acid as a catalyst for this being the most corrosive and the possibility of reuse of the polymer for several cycles.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

One of the most common forms of reuse is through API usage. However, one of the main challenges to effective usage is an accessible and easy to understand documentation. Several papers have proposed alternatives to make more understandable API documentation, or even more detailed. However, these studies have not taken into account the complexity of understanding of the examples to make these documentations adaptable to different levels of experience of developers. In this work we developed and evaluated four different methodologies to generate tutorials for APIs from the contents of Stack Overflow and organizing them according to the complexity of understanding. The methodologies were evaluated through tutorials generated for the Swing API. A survey was conducted to evaluate eight different features of the generated tutorials. The overall outcome of the tutorials was positive on several characteristics, showing the feasibility of the use of tutorials generated automatically. In addition, the use of criteria for presentation of tutorial elements in order of complexity, the separation of the tutorial in basic and advanced parts, the nature of tutorial to the selected posts and existence of didactic source had significantly different results regarding a chosen generation methodology. A second study compared the official documentation of the Android API and tutorial generated by the best methodology of the previous study. A controlled experiment was conducted with students who had a first contact with the Android development. In the experiment these students developed two tasks, one using the official documentation of Android and using the generated tutorial. The results of this experiment showed that in most cases, the students had the best performance in tasks when they used the tutorial proposed in this work. The main reasons for the poor performance of students in tasks using the official API documentation were due to lack of usage examples, as well as its difficult use.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In this work it was developed mathematical resolutions taking as parameter maximum intensity values for the interference analysis of electric and magnetic fields and was given two virtual computer system that supports families of CDMA and WCDMA technologies. The first family were developed computational resources to solve electric and magnetic field calculations and power densities in Radio Base stations , with the use of CDMA technology in the 800 MHz band , taking into account the permissible values referenced by the Commission International Protection on non-Ionizing Radiation . The first family is divided into two segments of calculation carried out in virtual operation. In the first segment to compute the interference field radiated by the base station with input information such as radio channel power; Gain antenna; Radio channel number; Operating frequency; Losses in the cable; Attenuation of direction; Minimum Distance; Reflections. Said computing system allows to quickly and without the need of implementing instruments for measurements, meet the following calculated values: Effective Radiated Power; Sector Power Density; Electric field in the sector; Magnetic field in the sector; Magnetic flux density; point of maximum permissible exposure of electric field and power density. The results are shown in charts for clarity of view of power density in the industry, as well as the coverage area definition. The computer module also includes folders specifications antennas, cables and towers used in cellular telephony, the following manufacturers: RFS World, Andrew, Karthein and BRASILSAT. Many are presented "links" network access "Internet" to supplement the cable specifications, antennas, etc. . In the second segment of the first family work with more variables , seeking to perform calculations quickly and safely assisting in obtaining results of radio signal loss produced by ERB . This module displays screens representing propagation systems denominated "A" and "B". By propagating "A" are obtained radio signal attenuation calculations in areas of urban models , dense urban , suburban , and rural open . In reflection calculations are present the reflection coefficients , the standing wave ratio , return loss , the reflected power ratio , as well as the loss of the signal by mismatch impedance. With the spread " B" seek radio signal losses in the survey line and not targeted , the effective area , the power density , the received power , the coverage radius , the conversion levels and the gain conversion systems radiant . The second family of virtual computing system consists of 7 modules of which 5 are geared towards the design of WCDMA and 2 technology for calculation of telephone traffic serving CDMA and WCDMA . It includes a portfolio of radiant systems used on the site. In the virtual operation of the module 1 is compute-: distance frequency reuse, channel capacity with noise and without noise, Doppler frequency, modulation rate and channel efficiency; Module 2 includes computes the cell area, thermal noise, noise power (dB), noise figure, signal to noise ratio, bit of power (dBm); with the module 3 reaches the calculation: breakpoint, processing gain (dB) loss in the space of BTS, noise power (w), chip period and frequency reuse factor. Module 4 scales effective radiated power, sectorization gain, voice activity and load effect. The module 5 performs the calculation processing gain (Hz / bps) bit time, bit energy (Ws). Module 6 deals with the telephone traffic and scales 1: traffic volume, occupancy intensity, average time of occupancy, traffic intensity, calls completed, congestion. Module 7 deals with two telephone traffic and allows calculating call completion and not completed in HMM. Tests were performed on the mobile network performance field for the calculation of data relating to: CINP , CPI , RSRP , RSRQ , EARFCN , Drop Call , Block Call , Pilot , Data Bler , RSCP , Short Call, Long Call and Data Call ; ECIO - Short Call and Long Call , Data Call Troughput . As survey were conducted surveys of electric and magnetic field in an ERB , trying to observe the degree of exposure to non-ionizing radiation they are exposed to the general public and occupational element. The results were compared to permissible values for health endorsed by the ICNIRP and the CENELEC .

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Os museus são instituições que desempenham um importante papel para a sociedade, com seus acervos de grande valor cultural e científico. É dever dos museus promover o acesso aos acervos e realizar ações de comunicação para divulgação e acesso público aos bens culturais que compõem suas coleções. Os museus vêm empregando a Tecnologia da Informação e Comunicação para apoiar suas atividades, ampliar o leque de serviços prestados à sociedade, promover a cultura, ciência e conhecimento, divulgar e disponibilizar seus acervos por meio da Web. Para disponibilizar as informações de acervos de museus, tornando uma navegação mais intuitiva e natural, e possibilitar a troca de informações entre os museus, visando a Recuperação da Informação, o reuso e interoperabilidade dos dados, é preciso adaptá-las para o formato da Web Semântica. Este estudo propõe uma solução para integrar os dados de acervos da Rede de Museus e Espaços de Ciências e Cultura da Universidade Federal de Minas Gerais e disponibilizá-los na Web, utilizando conceitos da Web Semântica e Linked Data. Para atingir esse objetivo, será desenvolvido um estudo experimental e um protótipo de aplicação para validá-lo e responder à pergunta de competência.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A sociedade impõe relações conscientes e saudáveis entre ela, consumidor, meio ambiente e economia de custo. Considerando os processos de retorno e descarte de resíduos, desenvolveram-se técnicas para que haja equilíbrio nas dimensões econômica, ambiental e social, sendo uma delas a logística reversa. Esse método minimiza as quantidades de resíduos descartados e promove seu reaproveitamento como fonte de matéria-prima em novos processos produtivos. No presente artigo, desenvolveu-se estudo de caso em uma recicladora que há doze anos coleta, classifica e separa materiais sólidos de indústrias do Distrito Industrial do Rio Grande (RS) para vendê-los a siderúrgicas e/ou comercializar subprodutos em condição de reuso no mercado local. Esse estudo tem por objetivo a análise das relações existentes entre as atividades logísticas reversas da recicladora em questão e as três dimensões da sustentabilidade. Tal análise justifica-se ao evidenciar como ocorre o processo de utilização da prática de logística reversa por uma organização intermediária, apontando-se sistematicamente as implicações ambientais, sociais e econômicas decorrentes de sua gestão.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Although very little is known about the transport, fate and toxic effects of medical compounds in aquatic environments, the presence of these compounds in potable water sources can no longer be overlooked. We can argue that trace concentrations of drugs in the water is relatively a minor problem, however, the current and future demands on global potable freshwater supplies will probably lead to greater incidents of indirect and direct water-reuse situations at the local, regional, and cross-border levels. It is important to remark that the solution of this emerging ecological issue does not rely on new and better wastewater treatment technologies, but a new paradigm of responsibility and the understanding of the relations between anthropogenic actions and their ecological effects as well. The objective of this brief communication is to present the state of the art of research conducted in the last decade in Europe and United States concerning the presence of pharmaceuticals products in aquatic environments.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The main issues related to water conservation in urban centers are the increase in water supply cost, demand growth, pollution and differences in the distribution of water resources. Water conservation, the controlled and efficient use of water, includes both measures as reasonable means of water reuse. Thus, conservation practices are an effective way to meet demand and supply water to new activities and users without jeopardizing the supplying water bodies and preserving the natural environment. This study aims to examine the water management of a shopping mall and the use of rainwater harvesting combined with greywater reuse. For buildings in general, water loss is common due to leaks in the hydraulic and restroom equipment. These losses, which are caused by a high volume of water used and wasted in the system, are often the result of design errors, incorrect maintenance procedures and users' bad habits In southern Brazil, where there is rainfall almost all year long, water shortages occasionally occur, particularly in some winter mouths. One difficulty that appears on rainwater studies is the proper determination of rainwater volume that can be used to address water supply systems. In this work, the simulation method was used to determine this volume. Thus, simulations with the following variables: rainfall, catchment area and water consumption were performed. For mall's hydraulic systems, segmented alternatives are adopted. That is, focusing on the use of rainwater or greywater reuse. Other alternatives of effluent reuse have been slightly discussed due to sanitary issues, those are effluents from toilets and kitchen sinks. The adoption of greywater may be feasible if there is a significant flow of greywater to comply water demand for toilet flushing. The inspections made in this study found that the quantity of sinks was insufficient to supply an adequate amount of water to toilets and urinals. The greywater reuse system was found to be infeasible in terms of demand and supply of water. Conversely, the rainwater harvesting system was entirely feasible and easily supplied water to all restrooms and contributed to the cooling of the air conditioning system with a short payback period. One of the challenges of this work was the need to compare the actual water consumption with a water consumption parameter used in buildings. Thus, a method that addresses the generation of specific consumption indexes for specific activity (like a mall) was used. The water consumption indices showed that this mall has a satisfactory water management program.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The central question of the research if inserts in thematic current and of relevance for the studies in Preservation and a Conservation of Historical Centers. It analyzes the relations between habitacional use, satisfaction of the inhabitants and preservation of the patrimony constructed in the Historical Center of São Luis-MA It considers that the use is factor that makes possible the transformation of spaces in places , prioritizing the point of view of the user as essential element to the analysis of the reality and that enriches the evaluation technique of the functional and formal aspects of the constructed environment. It is looked to understand the relation man-environment, and mainly, to verify as it happens throughout the process of the occupation and of appropriation of historical buildings destined to habitacional reuse, and still if this appropriation favors the preservation of the Historical Center of São Luís

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Elétrica, 2015.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The WTP produce many kinds of residue on your treatment stages, but the sludge is the more problematic from the final disposition point view. The actual rate of residue production deriving from technological evolution and the crescent population needs prevents the subtle equilibrium generation between consumption and recycling/reuse, creating problems of pollution resulting from inappropriate management of residues. Thus, is necessary achieve a new equilibrium between the grow from raw materials and energy and the residue generation. This equilibrium should be achieved by technical and economic feasibility of environmental supported models through recycling and reuse. The red ceramic industry stand out in residue absorption question as raw material due their clay mass heterogeneity, constituted by clay minerals and non-clay minerals with wide mineralogical variation, allowing residue inclusion which act like plastic or non-plastic materials, contributing to retain heavy metals contained in residues in the vitreous mass formed during the burning of the ceramic bodies. This work propose the study of the influence of incorporation of 25 wt.% sludge from wastewater treatment plant, according preliminary results, in the mass to produce ceramic bodies. The raw materials was characterized through chemical composition analyses by XRF, mineralogical analyses by XRD, thermal analyses by TG and DTA, Atterberg limits and thermodilatometry. Subsequently was composed the mass with 75 wt.% of clay and 25 wt.% of dried wastewater sludge from UFRN WWTP. Samples with 6,0 x 2,0 x 0,5 cm was produced with unidirectional compacting under pressure of 20MPa and burned in temperatures between 950 and 1,200ºC. After fired, the ceramic bodies have been submitted to physical and mechanical analyses through the measure of firing shrinkage, water absorption, density, apparent porosity and flexural strength; crystallographic analyses through XRD and microstructure analyses by SEM. The technological properties obtained was satisfactory to production of roof tiles with 25 wt.% at 1,200 ºC, but the production of others products at lower temperatures was not feasible

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Mestrado em Arquitetura Paisagista - Instituto Superior de Agronomia - UL

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The central question of the research if inserts in thematic current and of relevance for the studies in Preservation and a Conservation of Historical Centers. It analyzes the relations between habitacional use, satisfaction of the inhabitants and preservation of the patrimony constructed in the Historical Center of São Luis-MA It considers that the use is factor that makes possible the transformation of spaces in places , prioritizing the point of view of the user as essential element to the analysis of the reality and that enriches the evaluation technique of the functional and formal aspects of the constructed environment. It is looked to understand the relation man-environment, and mainly, to verify as it happens throughout the process of the occupation and of appropriation of historical buildings destined to habitacional reuse, and still if this appropriation favors the preservation of the Historical Center of São Luís

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Durante la década de los cuarenta y hasta mitad de los cincuenta, España se fundamenta en la intervención del Estado en todos los ámbitos y, es en este momento en el que se inicia la “Red Nacional de Silos y Graneros” con el fin de controlar la producción triguera. Este organismo construirá cientos de silos y graneros repartidos por todo el territorio español. Estas edificaciones en la actualidad se hallan la gran mayoría en desuso, aunque cada vez son más los casos de silos recuperados como el silo de Alcalá la Real, disfrutado por los vecinos de este municipio y aprovechado por la administración.