49 resultados para capacidade de retenção
em Universidade Federal do Rio Grande do Norte(UFRN)
Resumo:
The coatings mortars are essential elements of building structures because they execute an important role in protecting walls and are particularly exposed to aggressive action responsible for its degradation over time. The importance of wall coverings has been the subject of discussion and analysis in the conservation and rehabilitation of old buildings. Are sometimes removed and replaced with inappropriate solutions of constructive point of view or architecture. The most commonly used coatings on walls of old buildings is based on traditional hydraulic lime mortars. The present study aims at the formulation of new lime- based mortars and aerial fine aggregate, in order to contribute to a better field of conservation and restoration mortar coating of old buildings. Residue was used for polishing porcelain as fine aggregate, replacing the aggregate (sand), in percentages 05-30% by mass. We conducted a thorough evaluation of the mortar properties in fresh and hardened state by comparing the performance of the same with a reference mortar. The residue used was characterized as the density, bulk density, and particle size laser, scanning electron microscopy, X-ray diffraction and X-ray fluorescence. Formulations were produced 7, 6 with residue and one commonly used formulation, which served as a reference. In the formulations of lime mortars air (hydrated lime powder CH-I) has been adopted a stroke volume (1:3) with constant binder, was varied and the water / binder and aggregate and waste. For evaluation of mortars fresh, proceeded to consistency analysis, specific gravity, water retention and air content embedded. In the hardened state assays were performed in specific gravity, water retention, modulus of elasticity, tensile strength in bending, compressive strength, water absorption by capillary action, adhesion, tensile strength, resistance to shrinkage and salts by of crystallization trials with resources chloride solution, nitrate and sulfate all sodium in prismatic at 90 days of age, in addition to the micro structural analysis of mortars. Based on the results we can see that the mortar formulated with 10% content of waste and the reference free retraction feature more stable closer to neutrality. The composition of 10% was obtained better performance against the action of the salt crystallization. The mortar with 15% residue obtained better density, lower air content embedded and high capacity for water retention developing good workability. The replacement of 20% of waste generates a satisfactory utilization of resistance to compression, flexion and traction grip the base. And, finally, it can be seen that the mortar with 10, 15 and 20% residual show, in principle, good suitability as coatings, thus enabling a final result consistent with durability, workability and aesthetics developing therefore a material with better performance to repair or replace existing mortars in old buildings
Resumo:
In northeastern semiarid, seasonality on precipitation temporal distribution, high intensity storm events and inadequate management of native vegetation can promote soil erosion. Vegetation removal causes soil surface exposure, reduces soil water storage capacity and can be the source degradation processes. In this context, this approach aims to analyze water and soil erosion processes on a 250 m2 undisturbed experimental plot with native vegetation, slope 2.5% by using 2006 and 2007 monitoring data. The site was instrumented to monitor rainfall, overland flow runoff and erosion by using a 5 m³ tank downstream the plot. Soil erosion monitoring was made by transported sediment and organic matter collection after each event. Field infiltration experiments were made at 16 points randomly distributed within the plot area by using a constant head infiltrometer during drought and rainy seasons, respectively. Infiltration data revealed high spatial and temporal variability. It was observed that during the beginning of the rainy period, 77% of the events showed runoff coefficient less than 0.05. As the rainy season began, soil water increase produced annual species germination. High intensity storms resulted in runoff coefficients varying between 0.33 and 0.42. Once the annual species was established, it was observed that approximately 39% of the events produced no runoff, which reflects an increase on soil water retention capacity caused by the vegetation. A gradual runoff reduction during the rainy season emphasizes the effect of vegetative density increase. Soil erosion observed data allowed to fit an empirical relationship involving soil loss and precipitation height, which was used to analyze the plot installation impact on soil erosion. Observed soil loss in 2006 and 2007 was 230 Kg/ha and 54 Kg/ha, respectively
Resumo:
The improper disposal of nitrogen in receiving water courses causes problems such as toxicity to living beings through the consumption of oxygen to meet the nitrogen demand, eutrophication and nitrate contamination of aquifers. For this reason it is often necessary to be carried out complementary treatment of wastewater to eliminate or reduce the concentration of this compound in the wastewater. The objective of this study is to evaluate the biological removal of nitrogen compounds using submerged aerated and anoxic filters as post-treatment of an anaerobic system, with low cost and innovative technology, which in previous studies has shown high removal efficiency of organic matter and great potential biological nitrogen compounds removal. The simple design with perforated hoses for air distribution and filling with plastic parts proved to be very efficient in relation to organic matter removal and nitrification. The system presented, in the best stage, efficiency in converting ammonia to nitrate by 71%, and produced a final effluent concentration below 10 mg / L of NH3-N. In addition, carbon concentration was removed by 77%, producing final effluent with 24 mg/L COD. However, denitrification in anoxic filter was not effective even with the addition of an external carbon source. There was a reduction of up to 56% of nitrogen caused by the process of simultaneous nitrification and denitrification (SND). The high voids space presented by this type of support material coupled with direct aeration of the sludge, allows the respiration of biomass retained between the endogenous phase, increased cell retention time and sludge retention capacity, producing a final effluent with turbidity less than 5 UT and total suspended solids around 5.0 mg/L
Resumo:
Two methodologies were proposed to obtain micro and macroporous chitosan membranes, using two different porogenic agents. The methodologies proved to be effective in control the porosity as well as the pore size. Thus, microporous membranes were obtained through the physical blend of chitosan and polyethylene oxide (PEO) on an 80:20 (m/m) ratio, respectively, followed by the partial PEO solubilization in water at 80 ◦C. Macroporous chitosan membranes with asymmetric morphology were obtained using SiO2 as the porogenic agent. In this case, chiotsan-silica ratios used were 1:1, 1:3 and 1:5 (m/m). Membranes characterization were carried out by SEM (scanning electronic microscopy), X-ray diffraction, Fourier Transform Infrared Spectroscopy (FTIR), Thermal analysis (TG, DTG , DSC and DMTA). Permeability studies were performed using two model drugs: sodium sulfamerazine and sulfametoxipyridazine. By transmission FTIR it was possible to confirm the complete removal of SiO2. The SEM images confirmed the porous formation for both micro and macroporous membranes and also determined their respective sizes. By thermal analysis it was possible to show differences related with water sorption capacity as well as thermal stability for both membranes. DTG and DSC allowed evidencing the PEO presence on microporous membranes. The absorbance x time curves obtained on permeability tests for micro and macroporous membranes showed a linear behavior for both drugs in all range of concentration used. It was also observed, through P versus C curves, an increase in permeability of macroporous membranes according to the increase in porosity and also a decrease on P with increase in drug concentration. The influences of the drug molecular structure, as well as test temperatures were also evaluated
Resumo:
The coatings mortars are essential elements of building structures because they execute an important role in protecting walls and are particularly exposed to aggressive action responsible for its degradation over time. The importance of wall coverings has been the subject of discussion and analysis in the conservation and rehabilitation of old buildings. Are sometimes removed and replaced with inappropriate solutions of constructive point of view or architecture. The most commonly used coatings on walls of old buildings is based on traditional hydraulic lime mortars. The present study aims at the formulation of new lime- based mortars and aerial fine aggregate, in order to contribute to a better field of conservation and restoration mortar coating of old buildings. Residue was used for polishing porcelain as fine aggregate, replacing the aggregate (sand), in percentages 05-30% by mass. We conducted a thorough evaluation of the mortar properties in fresh and hardened state by comparing the performance of the same with a reference mortar. The residue used was characterized as the density, bulk density, and particle size laser, scanning electron microscopy, X-ray diffraction and X-ray fluorescence. Formulations were produced 7, 6 with residue and one commonly used formulation, which served as a reference. In the formulations of lime mortars air (hydrated lime powder CH-I) has been adopted a stroke volume (1:3) with constant binder, was varied and the water / binder and aggregate and waste. For evaluation of mortars fresh, proceeded to consistency analysis, specific gravity, water retention and air content embedded. In the hardened state assays were performed in specific gravity, water retention, modulus of elasticity, tensile strength in bending, compressive strength, water absorption by capillary action, adhesion, tensile strength, resistance to shrinkage and salts by of crystallization trials with resources chloride solution, nitrate and sulfate all sodium in prismatic at 90 days of age, in addition to the micro structural analysis of mortars. Based on the results we can see that the mortar formulated with 10% content of waste and the reference free retraction feature more stable closer to neutrality. The composition of 10% was obtained better performance against the action of the salt crystallization. The mortar with 15% residue obtained better density, lower air content embedded and high capacity for water retention developing good workability. The replacement of 20% of waste generates a satisfactory utilization of resistance to compression, flexion and traction grip the base. And, finally, it can be seen that the mortar with 10, 15 and 20% residual show, in principle, good suitability as coatings, thus enabling a final result consistent with durability, workability and aesthetics developing therefore a material with better performance to repair or replace existing mortars in old buildings
Resumo:
Discrepancies between classical model predictions and experimental data for deep bed filtration have been reported by various authors. In order to understand these discrepancies, an analytic continuum model for deep bed filtration is proposed. In this model, a filter coefficient is attributed to each distinct retention mechanism (straining, diffusion, gravity interception, etc.). It was shown that these coefficients generally cannot be merged into an effective filter coefficient, as considered in the classical model. Furthermore, the derived analytic solutions for the proposed model were applied for fitting experimental data, and a very good agreement between experimental data and proposed model predictions were obtained. Comparison of the obtained results with empirical correlations allowed identifying the dominant retention mechanisms. In addition, it was shown that the larger the ratio of particle to pore sizes, the more intensive the straining mechanism and the larger the discrepancies between experimental data and classical model predictions. The classical model and proposed model were compared via statistical analysis. The obtained p values allow concluding that the proposed model should be preferred especially when straining plays an important role. In addition, deep bed filtration with finite retention capacity was studied. This work also involves the study of filtration of particles through porous media with a finite capacity of filtration. It was observed, in this case, that is necessary to consider changes in the boundary conditions through time evolution. It was obtained a solution for such a model using different functions of filtration coefficients. Besides that, it was shown how to build a solution for any filtration coefficient. It was seen that, even considering the same filtration coefficient, the classic model and the one here propposed, show different predictions for the concentration of particles retained in the porous media and for the suspended particles at the exit of the media
Resumo:
Discrepancies between classical model predictions and experimental data for deep bed filtration have been reported by various authors. In order to understand these discrepancies, an analytic continuum model for deep bed filtration is proposed. In this model, a filter coefficient is attributed to each distinct retention mechanism (straining, diffusion, gravity interception, etc.). It was shown that these coefficients generally cannot be merged into an effective filter coefficient, as considered in the classical model. Furthermore, the derived analytic solutions for the proposed model were applied for fitting experimental data, and a very good agreement between experimental data and proposed model predictions were obtained. Comparison of the obtained results with empirical correlations allowed identifying the dominant retention mechanisms. In addition, it was shown that the larger the ratio of particle to pore sizes, the more intensive the straining mechanism and the larger the discrepancies between experimental data and classical model predictions. The classical model and proposed model were compared via statistical analysis. The obtained p values allow concluding that the proposed model should be preferred especially when straining plays an important role. In addition, deep bed filtration with finite retention capacity was studied. This work also involves the study of filtration of particles through porous media with a finite capacity of filtration. It was observed, in this case, that is necessary to consider changes in the boundary conditions through time evolution. It was obtained a solution for such a model using different functions of filtration coefficients. Besides that, it was shown how to build a solution for any filtration coefficient. It was seen that, even considering the same filtration coefficient, the classic model and the one here propposed, show different predictions for the concentration of particles retained in the porous media and for the suspended particles at the exit of the media
Resumo:
This study addresses the question of attraction and retention of talent in companies that produce engineering projects in the area of oil and natural gas in the city of Natal. The objectives were to identify the mechanisms that these companies use to attract and retain talented professionals and what the relationship between these practices and performance of these organizations in the market. This is a case study of a qualitative nature which were included in the fullness of companies that work in that class in the capital Potiguar. Have been applied to the managers of these companies structured questionnaires with eleven issues orientativas based on theoretical reference adopted. The research finds that managers understand the word "talent", recognize the importance of the appreciation of its employees and the development of their innate abilities to better organizational performance, much due to the fact they are acting in a market of fierce competition. His companies - though not submit the formal procedures related to the subject in question - have mechanisms that can be characterized as the attraction and retention of talent. The relationships identified in this study are consistent with the results found in other studies and put the information here can serve as the basis for that other managers, including other areas, to reach excellence in their respective industries
Resumo:
The aims of this study were: i) assessing the trophic state of the Mendubim reservoir (semi-arid, Rio Grande do Norte, Brazil; 05° 38 99,0 S 36°55 98,0 W) based on chlorophyll-a, total phosphorus and nitrogen concentrations and water transparency; ii) relating the patterns of temporal variation of zooplankton and phytoplankton to the trophic state of the reservoir and iii) investigating the carrying capacity of the reservoir for cage fish farming. The samplingwas done monthly from July 2006 to July 2007 in three stations at the reservoir: next to the dam (barrage), in the central region and in the mouth of the main tributary. The abiotic and biotic variables analyzed were: Secchi depth, volatiles and fixed suspended solids, chlorophyll-a, total phosphorus and nitrogen, TN:TP ratio and mesozooplankton and phytoplankton composition and biomass. The results showed that the reservoir can be considered as mesotrophic with mean concentrations of total nitrogen, phosphorus and chlorophyll-a equal to 1711, 1 μg.L-1, 30,8 μg.L-1 and 5,62 μg.L-1 respectively. The Cyanophyceae class was the most representative in terms of density, with the presence of potentially toxic species such as Microcystis aeruginosa, Planktothrix planctonica, Cylindrospermopsis raciborskii, Aphanizomenon sp. ,Aphanocapsa delicatissima and Pseudanabaena acicularis. Among the zooplankton, the genus Notodiaptomus presented the largest biomass values. Overall, our results show that the light limitation should explain the weak relationship between chlorophyll-a and total phosphorus and nitrogen concentrations. We concluded that the water of Mendubim reservoir is suitable for intensive fish cage aquaculture. Based on the carrying capacity calculations for this reservoir, we found that the maximum sustainable yield of tilapias in cages in the reservoir is 126 ton per year assuming a factor of food conversion of 1.5: 1.0 and a phosphorus content in the fish food of 1%
Resumo:
The eutrofization is a natural process of accumulation of nutrients in aquatic´s body that it has been accelerated for the human´s actives, mainly the related with the activities of camp, industrial and the inadequate disposition of the domestic sewage. The enrichment of the aquatic´s body with nutrients, mainly the nitrogen and the phosphorus, and the consequent proliferation of algae and Cyanobacteria can commit the quality of the water for the public provisioning, for the fish farming and for other ends. The problem becomes more critical when there is a shortage of water naturally as in the semi-arid area of the Brazilian northeast. Before that problem this work had as objective evaluates the trophic state of six reservoirs of the basin of River Seridó of Rio Grande of Norte and also estimate the capacity of load of match of the reservoir and risk probabilities based on the established limits by the resolution Conama 357/05. The results demonstrate that the six reservoirs are eutrofization, with concentration of total phosphorus and cloro a in the water upster to 50 e 12 μg l-1. The results show that space homogeneity exists in the state trophic of the reservoirs, but a significant variation interanual in function of the increase of the concentrations of nutrients and decrease of the transparency of the water with the reduction of the body of water accumulated in the reservoirs.The results of the simulation risk estocastic show that the reservoirs could receive annually from 72 to 216 Kg of P, assuming a risk of 10% of increasing in more than 30 μg l-1 the annual medium concentrations of total match in the water of these reservoirs. This load could be high in until 360 kg of P a year in case the managers assume a risk of 10% of increasing in more than 50 μg l-1 the annual medium concentrations of total phosphorus in the waters of these reservoirs
Resumo:
The aim of this study was to evaluate the pain influence regarding location, intensity and duration over functional capacity in institutionalized elderly (Fundacao Leur Brito). This is a descriptive exploratory study with a transversal design and quantitative approach. The population of the study was composed of 60 elderly, being 50% males with 60 years-old minimum age and 104 years-old maximum age, with mean age 77,6 (?}11,64) years-old. Data was collected by a structured query formulary divided in four parts: 1) Social, health and demographic characterization; 2) Pain related aspects (time and location); 3) Pain evaluation by numeric scale and 4) Functional capacity measured by Barthel Index. It was observed after evaluation by Squared-chi test (x2) statistical significant difference between pain presence and Barthel Index activities: bath (pvalue=0,015), dressing (p-value= 0,041), intimal hygiene transference (p-value=0,001), chair and bed transference (p-value=0,032), walking (p-value=0,010) and go upstairs (p-value=0,008). It was also observed statistical difference between total Barthel score (dependent/independent) and pain presence, p-value<0, 000. Through data obtained by this study, a multiprofessional approach is necessary to proper pain control and maintenance and/or regain of functional capacity, leading to an increase in life quality with more independence and autonomy to elderly
Resumo:
(Objective) Assess the functional capacity and determine the difference between the means of functional capacity (basic and instrumental activities of daily living) and the age groups of elderly residents in an outlying area in the hinterland of Bahia/Northeast of Brazil. (Methods) Analytical study with cross-sectional design and a sample of 150 elderly individuals enrolled in four Health Units in the municipality of Jequié, Bahia, Brazil. The instrument consisted of sociodemographic and health data, the Barthel Index and the Lawton scale. (Results) In all, 78.00% of the elderly were classified as dependent in the basic activities and 65.33% in the instrumental activities of daily living. Using the Kruskal- Wallis test, we found a statistically significant difference between the means of instrumental activities and the age groups (p= 0.011). (Conclusion) An elevated number of elderly were classified as dependent in terms of functional capacity and increased age is related to greater impairment in the execution of instrumental activities of daily living
Resumo:
A incapacidade funcional e o déficit cognitivo são condições relacionadas com o processo de envelhecimento humano. O déficit cognitivo é considerado um importante fator preditor de prejuízos funcionais em populações idosas. Este estudo teve um caráter multidisciplinar na sua elaboração e execução, contando com profissionais de distintas áreas da saúde. Trata-se de um estudo transversal que analisou a associação do desempenho cognitivo na capacidade funcional de uma amostra populacional idosa residente em Natal-RN. Foram avaliados 213 idosos pelo Questionário Multidimensional BOAS e pelo Mini-Exame do Estado Mental (MEEM). Através de análise multivariada, mediante regressão linear, os resultados apontam a idade e o nível de escolaridade como fatores associados ao desempenho cognitivo nos idosos do estudo. O modelo explicativo final elaborado através de regressão logística apresentou o desempenho cognitivo como a única variável associada à incapacidade funcional para as atividades da vida diária, mesmo quando ajustado por variáveis sócio-demográficas. A identificação dos fatores, associados ao declínio do estado funcional dos idosos que vivem na comunidade, poderá reduzir o impacto dessas condições na capacidade funcional através da aplicação de medidas preventivas voltadas para este fim
Resumo:
A prática regular de exercício físico possibilita redução dos efeitos das disfunções hormonais e envelhecimento biológico natural que promovem desajustes hemodinâmicos, vasculares e músculo-esqueléticos, principalmente na população feminina no período pós-menopausa. Nesta fase da vida, o exercício aquático representa mais do que uma forma de ajuste funcional, é uma forma de manutenção de independência para as atividades da vida diária (AVD s) e melhoria na qualidade de vida. Este estudo teve como objetivo avaliar as modificações adquiridas pela prática regular de um programa de exercício aquático concorrente de intensidade moderada no nível de óxido nítrico (ON), no índice de resistividade arterial (IR), no perfil lipídico, na capacidade funcional e na qualidade de vida de idosas. A amostra foi formada por idosas (60 a 80 anos) selecionadas por randomização, por sorteio simples divididas em grupo controle e grupo de intervenção as quais foram submetidas a um programa de exercícios aquáticos proposto inicialmente em projeto piloto, por 12 semanas (n=34) e o ensaio clínico teve duração de 16 semanas (n=40). Foi coletada amostra sanguínea das idosas e avaliado o perfil lipídico pelo método enzimático com kit Labtest e o ON por medida indireta a partir da concentração de nitrito no sobrenadante das células em cultura em leitor de ELISA. A avaliação das artérias carótidas e vertebrais foi feita utilizando o método de ultra-som Doopler. A capacidade funcional foi avaliada por quatro testes que simulam atividades da vida diária que são: caminhar 10 metros (C10m), levantar da posição sentada (LPS), levantar da cadeira e locomover-se pela casa (LCLC) e o de levantar-se da posição decúbito ventral (LPDV). No estudo piloto foi avaliado o índice geral de autonomia funcional (IG) e a qualidade de vida através do questionário WHOQOL-100. Empregou-se a análise de variância (ANOVA) com medidas repetidas nos fatores grupo (GH e GC) e tempo (pré e pós-teste) para as comparações intra e intergrupos nas variáveis seguida do post hoc de Scheffé. Utilizou-se o teste de correlação de Pearson e adotado o valor de p<0,05 para a significância estatística. Houve aumento do ON circulante, redução nos índices de resistividade arterial, melhoria significativa nos níveis de colesterol e triglicérides e ganho na capacidade funcional das idosas após a intervenção. Existiu correlação inversa entre a resistividade da artéria vertebral direita (VERTD) e níveis de ON e entre a VERTD e os níveis plasmáticos de HDL, assim como entre estes e o teste C10m nas idosas em estudo. Não houve modificações significativas na qualidade de vida das idosas. Em conclusão, o programa de exercício proposto foi capaz de oferecer melhorias funcionais, aumentar o nível de óxido nítrico circulante, diminuindo a resistência arterial promovendo modificações no perfil lipídico de idosas
Resumo:
O estudo tem como objetivo principal comparar o limiar e a tolerância à dor em mulheres com fibromialgia e mulheres sem sintomas de dor, correlacionando com capacidade funcional, qualidade do sono e força de preensão manual. Trata-se de um estudo descritivo de corte transversal realizado na Universidade Potiguar e na Universidade Federal do Rio Grande do Norte, envolvendo uma equipe multidisciplinar com fisioterapeutas, médicos e educadores físicos. Setenta e duas mulheres foram divididas em dois grupos: grupo com fibromialgia (GF, n = 40) e grupo controle (GC, n = 32) sem sintomas de dor, pareadas por idade e índice de massa corporal. Questionários foram usados para medir capacidade funcional (Fibromyalgia Impact Questionnaire FIQ) e qualidade do sono (Pittsburgh Sleep Quality Index - PSQI). Limiar e tolerância à dor foram medidas por um algômetro de pressão e para determinar força foi usado um dinamômetro de preensão manual. Na análise estatística o teste T de Student foi usado para comparar grupos e o coeficiente de correlação de Spearman foi usado no GF para correlacionar limiar e tolerância à dor com as demais medidas. O GF mostrou piores resultados nas medianas comparado ao GC: limiar de dor 2 kg/cm2 versus 5,5 kg/cm2 (p <0,001), tolerância à dor 2,8 kg/cm2 versus 7,2 kg/cm2 (p <0,001) e força de preensão manual 14,5 kgf versus 25,2 kgf (p <0,001). Adicionalmente os dois questionários apresentaram resultados piores também no GF em relação ao GC, respectivamente: FIQ 65 versus 14,3 (p <0,001) e PSQI 13 versus 5 (p <0,001). No GF foi observada correlação negativa tanto entre o limiar de dor quanto a tolerância à dor com os escores do FIQ e do PSQI. No GF foram observadas correlações positivas tanto entre o limiar de dor (p <0,01) quanto a tolerância à dor (p <0,01) com força de preensão manual. É possível concluir que limiar de dor e tolerância à dor estão correlacionados com capacidade funcional, qualidade do sono e força de preensão manual em mulheres com fibromialgia