• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 13
  • 11
  • 3
  • 1
  • 1
  • 1
  • Tagged with
  • 32
  • 10
  • 9
  • 9
  • 8
  • 6
  • 6
  • 6
  • 6
  • 6
  • 6
  • 6
  • 6
  • 5
  • 5
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Efeitos do exercício resistido na fase hospitalar do pós-operatório de revascularização do miocádio / EFFECTS OF WEATHERED EXERCISE IN THE HOSPITALAR PHASE OF POSTOPERATIVE OF THE MIOCÁDIO REVASCULARIZATION

Ximenes, Nayana Nazaré Pessoa Sousa 21 November 2014 (has links)
Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-05-16T19:35:17Z No. of bitstreams: 1 NayanaXimenes.pdf: 1996792 bytes, checksum: 8b0defdcfad78f68778fa5403df3c0ef (MD5) / Made available in DSpace on 2017-05-16T19:35:17Z (GMT). No. of bitstreams: 1 NayanaXimenes.pdf: 1996792 bytes, checksum: 8b0defdcfad78f68778fa5403df3c0ef (MD5) Previous issue date: 2014-11-21 / Regular physical activity has been beneficial post - cardiac surgery. Early resistance exercise training improves functional capacity, clinical status, cardiac function and survival of patients, leading to a reduction of the harmful effects of prolonged bed rest, reduced care costs and hospital stay. Objective: To evaluate the effects of resistance exercise during hospital postoperative coronary artery bypass grafting (CABG). Methods: It was performed a randomized controlled trial with 37 patients subjected to isolated CABG between August 2013 and May 2014, distributed by simple drawing into two groups: control group (n = 20) that received conventional physiotherapy and intervention group (n = 17) underwent resistance exercise. Pulmonary function and functional capacity were assessed preoperatively, on discharge from the intensive care unit (ICU) and hospital discharge by spirometry and six minute walk test (6MWT). For statistical analyze were utilized Shapiro-Wilk, Mann-Whitney, Student's t, Fisher and G tests. Variables with p < 0.05 were considered significant. Results: The groups were homogeneous in terms of demographic, clinical, and surgical variables. No effect of resistance exercise on pulmonary function was observed when compared to control group. However, in intervention group it was maintained functional capacity during assessments periods when compared to the control group which was observed significant reducing (p < 0.0001). It was Observed a significant reduction in length of hospital stay (6.3 ± 1 2 vs. 7.6 ± 2.5 days) (p = 0.03). Conclusion: In this study, the resistance exercise during hospital CABG postoperative provided maintaining functional capacity and reduction of hospital stay when compared to conventional physiotherapy. / A prática de atividade física tem sido benéfica pós - cirurgia cardíaca. O exercício resistido precoce melhora a capacidade funcional, quadro clínico, função cardíaca e sobrevida dos pacientes, promovendo a diminuição dos efeitos prejudiciais do repouso prolongado no leito, redução dos custos com a assistência e tempo de internação hospitalar. Objetivo: avaliar os efeitos do exercício resistido na fase hospitalar do pós-operatório de revascularização do miocárdio (RM). Métodos: realizou-se um ensaio clínico controlado randomizado com 37 pacientes submetidos à RM isolada, com circulação extracorpórea entre agosto de 2013 e maio de 2014, distribuídos por sorteio simples em dois grupos: grupo controle (n = 20) que realizou fisioterapia convencional e grupo intervenção (n = 17) submetidos ao exercício resistido. A função pulmonar e a capacidade funcional foram avaliados no pré-operatório, alta da unidade de terapia intensiva (UTI) e alta hospitalar pela espirometria e teste de caminhada de seis minutos (TC6M). Para análise estatística empregaram-se os testes de Shapiro-Wilk, Mann-Whitney, t-Student, Fisher e G. variáveis com p < 0,05 foram consideradas significativas. Resultados: Os grupos apresentaram-se homogêneos quanto às variáveis demográficas, clínicas e cirúrgicas. Não se observou efeito do exercício resistido na função pulmonar quando comparado ao grupo controle. Entretanto, no grupo intervenção houve manutenção da capacidade funcional nos três períodos avaliados quando comparado ao grupo controle para o qual se observou queda significativa (p < 0,0001).Observou-se redução significativa do tempo de internação hospitalar (6,3 ± 1,2 vs. 7,6± 2,5 dias) , (p = 0,03) .Conclusão:No presente estudo, o exercício resistido na fase hospitalar do pós-operatório de RM proporcionou manutenção da capacidade funcional e redução do tempo de internação hospitalar quando comparado a fisioterapia convencional.
2

EVALUATION OF THE PERFORMANCE OF FLOCCULATION TO ENHANCE SEDIMENT TRAP EFFICIENCY

Scott, Derek 01 January 2015 (has links)
Weathered sandstone materials have seen increased use in reclamation due to the wide-spread adoption of the Forest Reclamation Approach (FRA) in Appalachia. Runoff from these newly FRA reclaimed sites has the potential to adversely impact aquatic environments without fine sediment retention. To reduce the size and capital investment of settling ponds, flocculant utilization was investigated. Preliminary jar tests were conducted using composite weathered mine spoil samples acquired from a surface coal mine in eastern Kentucky. Four flocculants from the Magnafloc family of products were investigated during the initial screening-level testing. Experiments were conducted at three initial sediment concentrations (500 mg/L, 2,500 mg/L and 5,000 mg/L). A nonionic flocculant, Magnafloc 351, performed best, reducing total suspended sediment to below 50 mg/L. Large scale experiments confirmed that Magnafloc 351 was effective in reducing sediment concentrations. Jar tests were expanded to determine age and environmental effects on a Magnafloc 351 solution. Magnafloc 351 performance was slightly reduced after storage in a controlled building environment for 30 days and significantly decreased after 120 days. Magnafloc 351 solution exposed to UV and high heat (111°F) was ineffective after 30 days, while storage at 4°F and 36°F for 30 days did not adversely influence performance.
3

Phytoremediation of Weathered Petroleum in Groundwater by Arroyo Willows in Nutrient Amended On-Site Mesocosms

Bragg-Flavan, Sarah E 01 March 2009 (has links)
PHYTOREMEDIATION OF WEATHERED PETROLEUM IN GROUNDWATER BY ARROYO WILLOWS IN NUTRIENT AMENDED ON-SITE MESOCOSMS SARAH BRAGG-FLAVAN A large-scale mesocosm study was conducted to determine if vegetation with willow trees enhances biodegradation and to evaluate the mechanisms of natural biodegradation of weathered petroleum compounds under field conditions. The mesocosms were designed to model conditions at a former oil field where mid-range petroleum distillates were used as a diluent for pumping crude oil contaminated the soil and groundwater at the site with petroleum compounds. Ten mesocosms were constructed at the field site using un-impacted soil and diluent-impacted groundwater from the site. Five of the mesocosms were planted with Arroyo Willow trees native to the field site and the other five served as controls without trees. Since these willow trees are phreatophytes, their roots are capable of consuming water from the water table. A previous study was conducted using these mesocosms, however the willow trees then were in poor condition. In this study, fertilizer was added to the mesocosms to promote healthy growth of the willows. Fertilizer was added equally to mesocosms with and without willow trees to avoid introducing bias. Groundwater was circulated through the mesocosms for two 109 to 126 days runs, while the total petroleum hydrocarbon (TPH) concentrations of the groundwater were measured periodically. Dissolved oxygen concentrations were also monitored in each of the mesocosms to determine if the willow trees had any impact on oxygen transfer to the subsurface. In the first run without nutrient amendments the trees did not enhance biodegradation. All the mesocosms started with an average TPH concentration of 6.3 mg/L and ended with a concentration of 1.0 mg/L. After this first run, nutrient amendments were added to all the mesocosms, resulting in healthy trees with robust growth. With healthy willow trees, the planted mesocosms resulted in a statistically significant increase in long-term biodegradation of dissolved-phase petroleum compounds. The planted mesocosms resulted in 29 percent more degradation. These results agree with prior lab studies using bench-scale microcosms with media from the former oil field which indicated that TPH concentrations after 100 days were lower in containers with willows or lupines compared to controls without plants. Microtox® toxicity decreased for both planted and control mesocosms, showing no toxic root exudates or by-products. There are several potential mechanisms of the observed phytoremediation. Terminal restriction fragment analyses showed that the planted mesocosms had different microbial communities than the unplanted mesocosms. Thus, a possible mechanism of the phytoremediation is stimulation of a rhizobial microbial community that biodegrades petroleum compounds. The dissolved oxygen (DO) concentrations were actually lower in the planted mesocosms, possibly due to consumption of oxygen during biodegradation of root exudates. The reduced DO concentrations in the planted mesocosm discounts the possibility that the plants stimulated biodegradation by increasing oxygen transfer to the subsurface. It is not known from these experiments if the petroleum compounds were taken up by the plants or if the plants stimulated bacterial biodegradation. Since it is difficult for plants to uptake non-polar compounds with a high octanol-water coefficient (Kow), it is usually unlikely that plants could uptake petroleum compounds which usually have a Kow > 3. However, the log Kow of the dissolved phase diluent determined in this research was only 0.14. Although the mechanism by which the willow trees increased biodegradation was not elucidated, this study demonstrated that phytoremediation of the polar and hydrophilic weathered petroleum compounds was successful. Column chromatography was used to fractionate petroleum compounds extracted from the groundwater into aliphatic, aromatic and polar components so that biodegradation of each of these fractions could be determined independently. The first mesocosm experiments showed that regardless of the presence of trees, there was a decrease in TPH concentration for all three fractions. The overall unfractionated biodegradation rates averaged 41 ug/L/day over this experiment, and the biodegradation rate of the polar fraction was similar at 40 ug/L/day. In comparison, the biodegradation rates of the aliphatic and aromatic fractions were considerably lower at 1.2 and 2.6 ug/L/day, respectively.
4

Comportamento ambiental de sulfadiazina em solos brasileiros / Environmental behavior of sulfadiazine in brazilian soils

Reia, Marina Yasbek 16 May 2013 (has links)
A manutenção da qualidade do solo como um recurso natural vital à humanidade tem impulsionado a pesquisa sobre a dinâmica ambiental de resíduos de antibióticos veterinários no ambiente. Os processos de sorção, degradação e lixiviação da sulfadiazina (SDZ) foram avaliados em quatro solos com atributos físico-químicos distintos, conforme o uso de técnicas radiométricas e os protocolos da OECD para pesticidas. Os coeficientes de sorção (Kd) da SDZ variaram de baixo a muito alto (2,6 a 80 L kg-1). O seu baixo potencial de dessorção (< 24,2% do sorvido ou < 12,1% do aplicado) ratifica a existência de mecanismos específicos envolvidos na sorção da SDZ, afora as interações eletrostáticas e a partição hidrofóbica apontadas pelos estudos prévios. Em concentrações residuais próximas às encontradas em campo (??84 ?g kg-1), o potencial de sorção da SDZ foi consideravelmente maior do que em altas concentrações. A dissipação da SDZ foi rápida em todos os solos (t1/2 < 2,7 dias) e a formação de resíduos ligados foi a principal via de dissipação, correspondendo a > 78% do aplicado após 7 dias. A taxa média de mineralização foi < 3% do aplicado. A presença do antibiótico não impactou a biomassa do solo, indicando que em doses crônicas os efeitos sejam imperceptíveis em curto prazo. Apesar do potencial de mobilidade, a SDZ apresentou baixo potencial de lixiviação nos solos (< 0,11% do aplicado). Já a redistribuição da SDZ foi maior no perfil dos solos recém-aplicados do que nos envelhecidos e a grande maioria permaneceu nos primeiros 5 cm (> 95 % do aplicado). Nos solos envelhecidos, a sua mobilidade foi praticamente nula (0,06% do aplicado). Os resultados da pesquisa contribuem para elucidar a dinâmica de contaminantes orgânicos em solos intemperizados e ácidos de regiões tropicais, o que poderá auxiliar modelos de avaliações de risco, ações de mitigação, entre outros. / The soil quality as a vital resource for humanity has driven research on the occurrence, environmental fate and behavior of antibiotic residues in the environment. Sorption, leaching and degradation tests were performed on four soils with distinct physic-chemical attributes with 14C-sulfadiazine, following guidelines developed by OECD (USA) for laboratory studies. As the development of research on the subject has its origins in temperate countries, the soil and climatic conditions occurring in the tropics resulted in variations in the dynamic of sulfadiazine, mainly due to conditions of weathered and acidize.The results showed higher Kd (from 3, 5 to 80 L kg-1) for the residual concentration detected in monitoring studies, rapid dissipation (DT 50 between 2 and 3 days) and reduced leaching potential, in contrast with rates reported in the literature. The formation of bound residues was the major route of dissipation in all soils, reaching values between 78 % and 89 % of the total in just 7 days, whereas the mineralization did not exceed 1.5% throughout the experiment. The analysis of the variation of microbial-biomass carbon as an negative effect of antibiotic, present no difference with the content in the control, as reported by several studies that argue that the effects of chronic doses are imperceptible in short term. Although the knowledge about processes transformation of organic chemicals in soils is very divergent, laboratory tests contributed to a first elucidation about environmental of antibiotic residues, contributing to the improved performance of models to compose risk assessments and mitigation actions in tropical soils, for example.
5

Extração sequencial e cinética de sorção de cádmio em solos tropicais / Cadmium sequential extraction and sorption kinetics in tropical soils

Colzato, Marina 02 December 2016 (has links)
A interação de elementos potencialmente tóxicos com solos e a caracterização quanto à mobilidade e potencial de liberação ao ambiente são importantes para avaliação de risco ambiental. No caso de solos altamente intemperizados, como os Latossolos, a interação pode ser diferenciada devido à elevada acidez, baixa densidade de cargas negativas, maiores quantidades de minerais de argila 1:1 e de (hidr)óxidos de Fe, Al e Mn, em que predominam cargas negativas variáveis com o pH. O objetivo nesta tese foi caracterizar a capacidade de sorção, a distribuição entre as frações do solo, a especiação temporal, a predição da capacidade de sorção e a dessorção com método dinâmico de extração de Cd(II) em seis solos tropicais, incluindo três Latossolos. Amostras dos seis solos foram utilizadas para avaliação da interação com Cd(II), utilizando extração sequencial e especiação por espectroscopia de absorção de raios-X próximo à estrutura da borda (XANES) para avaliação da cinética de sorção. Dados de 29 solos foram utilizados para desenvolvimento de modelo de regressão linear para predição das capacidades de sorção de Cd(II). A caracterização da dessorção de Cd por extração convencional e dinâmica foi feita em solos de textura médio-arenosa, argilosa e em um solo de referência certificado. Os resultados de sorção foram ajustados ao modelo de Langmuir. As capacidades de sorção e as energias livres padrão de Gibbs variaram de 37 à 1296 mg kg-1 e de -16,6 até -27,0 kJ mol-1, respectivamente. A sorção foi fraca e reversível, e mais de 90% do Cd estava sorvido como espécies disponíveis. A especiação temporal indicou evidências fracas e variáveis para as alterações químicas do Cd no solo, sugerindo que o elemento liberado nessas amostras se ligou à matéria orgânica do solo e aos óxidos minerais ou permaneceu dissolvido, com pequenas alterações na especiação nos meses seguintes. O modelo linear representou 98% dos resultados empíricos apenas em função de uma variável, que foi o ensaio de sorção simplificado com apenas uma concentração de Cd(II). Apesar de a capacidade de sorção prevista com o modelo ter apresentado variação de cerca de 20% em relação ao empírico, o modelo de predição apresenta potencialidade de aplicação para avaliações iniciais e rápidas. A dessorção avaliada em batelada e em fluxo indicou dessorção próxima de 100% nas frações que representam disponibilidade no ambiente, enquanto o sistema desenvolvido para extração dinâmica foi adequado na mistura das soluções com a amostra de solo e propiciou rápida troca de extratores. De modo geral os atributos do solo, bem como a classe, influenciaram, mas não definiram a interação do Cd(II) com o solo. Por sua vez, o Cd(II) incorporado ao solo apresenta grande risco ambiental e de interação com a biota / The interaction of potentially toxic elements in soils and characterization as mobility and potential of environmental release are important for environmental risk assessment. In the case of highly weathered soils, as Oxisols, interaction can be differentiated, due to the high acidity, low density of negative charges, and higher amounts of 1:1 clay minerals and Fe, Al and Mn (hidr)oxides, in which negative charges are variables with pH. The objectives in this thesis was to characterize the Cd(II) sorption capacity, distribution between soil fractions, temporal speciation, prediction of sorption capacity and desorption with dynamic extraction method in six tropical soils, including three Oxisols. Samples of the six soils were used to assess the interaction with Cd(II) using sequential extraction and the speciation with X-ray absorption near edge structure spectroscopy (XANES) to evaluate the adsorption kinetics. Data of 29 soils were used to develop a linear regression model for prediction of Cd(II) sorption capacity. The Cd desorption characterization trough conventional and dynamics extractions was performed in a medium-sandy, a clayey and a certified reference soils. The sorption results were fitted to the Langmuir model. Sorption capacities and standard Gibbs free energy ranged from 37 to 1296 mg kg-1 and from -16.6 to -27.0 kJ mol-1, respectively. Sorption was weak and reversible, and more 90% Cd was sorbed as available species. The temporal speciation indicated weak and variables evidence of chemical changes of Cd in the soil, suggesting that this element released in these soils bound to the soil organic matter and to mineral oxides or remained dissolved, with minor changes in speciation in the following months. The linear model accounted for 98% of empirical results only on the basis of a single variable, which was the sorption simplified experiment with only one Cd(II) concentration. Although the sorption capacity predicted with the model ranged about 20% of the empirical, prediction model has potential of application for initial and rapid assessments. The desorption evaluated in batch and flow indicated desorption of about 100% in the fractions representing availability in the environment, meanwhile the system developed for dynamic extraction was adequate to mix the solutions with the soil sample and provided rapid exchange of extractants. Overall, the soil characteristics and the class had influence, but did not define the interaction of Cd(II) with the soil. On the other hand, the Cd(II) incorporated into the soil has a great environmental risk and to interact with the biota
6

Dinâmica do fósforo no solo em função da adição de ácidos orgânicos de baixa massa molar / Phosphorus dynamics in soils amended with low molar mass organic acids

Santos, Sheila Renata 16 February 2016 (has links)
A baixa eficiência da adubação fosfatada em solos altamente intemperizados é devido, entre outros fatores, à adsorção do fósforo (P) à superfície das argilas silicatadas do tipo 1:1 e, principalmente, dos (hidr)óxidos de Fe e de Al. Manejos do solo que induzem a solubilização de formas de P indisponíveis para as plantas têm sido intensamente estudados nos últimos anos. Uma tentativa de aumentar a concentração de P disponível na solução do solo para sua absorção pelas plantas é a mobilização de P por ânions de ácidos orgânicos de baixa massa molar (AOBMM). Ânions derivados de AOBMM exsudados pelas raízes de plantas ou excretados por microrganismos são associados com algumas condições de rizosfera como deficiência de P e fitotoxidez de Al e interagem com o solo de forma a aumentar a biodisponibilidade de P. Dependendo dos atributos do solo, do grau de dissociação, das propriedades e do número de grupos carboxílicos dos ânions orgânicos, o P pode ser mobilizado do solo principalmente devido à dissolução complexométrica de minerais e à adsorção competitiva dos grupos funcionais carboxílicos e fosfato nos sítios de superfície coloidais. A capacidade dos ânions citrato, malato e oxalato em mobilizar P de amostras de um Neossolo Quartzarênico típico (RQ) e de um Latossolo Vermelho ácrico (LVwf) foi avaliada por meio de um estudo de lixiviação de ânions em colunas. Devido a não detecção de P nos efluentes das colunas com LVwf, foi realizado outro estudo em colunas, no qual somente citrato foi lixiviado, mas num volume maior, e as alterações das formas de P nas amostras desse solo induzidas pela lixiviação de citrato foram identificadas por espectroscopia de absorção de raios-X na borda K do fósforo (X-ray absorption near edge structure -XANES - spectroscopy). A capacidade dos ânions de AOBMM em solubilizar P foi mais dependente do teor de P disponível e de outros atributos do solo que do número de grupos funcionais carboxílicos dos ânions orgânicos. Somente o oxalato mobilizou P do RQ, enquanto todos os ânions de AOBMM foram capazes de mobilizar P do LVwf. Quando baixos volumes de solução contendo ânions de AOBMM foram lixiviados no solo, além do aumento do pH, a mobilização de P foi acompanhada pela mobilização de Al no RQ (pH água = 5), e pela mobilização de Ca no LVwf (pH água = 5.6), o que indica solubilização de P pela complexação de Al, Ca, ou Fe, de fosfatos insolúveis, ou pela inibição da precipitação de P com esses metais. Ao lixiviar um volume maior de citrato no LVwf, o P também não foi detectado nos efluentes das colunas, mas houve lixiviação intensa de Al e Fe, bem como mudanças nas proporções de formas de P no solo caracterizadas pelos espectros XANES. Embora tenhamos encontrado indícios da ação dos principais mecanismos de solubilização de P (dissolução complexométrica de minerais e troca de ligantes entre grupos funcionais carboxílicos e P adsorvido ao solo), os ânions de AOBMM mostraram pouco potencial de efetivamente aumentar a biodisponibilidade de P. / Phosphate fertilization of acidic, highly weathered soils is inefficient because of the adsorption of phosphorus (P) to 1:1 silicate clays and, especially, to Fe and Al oxides. Different soil management practices to induce solubilization of unavailable forms of P to plants nutrition have been intensively studied in recent years. The mobilization of P with anions of low molecular weight organic acids (LMWOA) increases the concentration of available P in the soil solution for plant uptake. Anions derived from LMWOA exudates from plants root or excreted by microbes are associated with some rhizosphere conditions, as deficiency of P and Al phytotoxicity, and they interact with the soil in order to increase P availability. Depending on the soil attributes, and degree of dissociation, properties, and number of carboxyl groups from organic anions, P can be mobilized from soil mainly because of complexometric dissolution of soil minerals and ligand exchange of functional carboxyl groups and P adsorbed in soil surface sites. The capacity of citrate, malate and oxalate anions to mobilize P from a Typic Quartzipsamment (RQ) and an Anionic Acrudox (LVwf) was evaluated in a column leaching study. Because no P was detectable in columns effluents from LVwf, another column leaching study was performed, but only citrate was leached with a greater volume of solution, and citrate-induced changes at P forms in the soil were identified by P K-edge X-ray absorption near edge structure - XANES - spectroscopy. The capacity of LMWOA anions to solubilize P was more dependent of P status and other soil attributes, than number of carboxyl groups of organic anions. Only oxalate mobilized P from RQ, and all LMWOA anions were able to mobilize P from LVwf. Increasing of P mobilization and soil pH were followed by increases of Al mobilization from RQ (pH water = 5), and Ca mobilization from LVwf (pH water = 5.6) at lower volumes of LMWOA anions leaching. Phosphorus was solubilized by complexation of Al, Ca or Fe from insoluble phosphate minerals, or by inhibition of Al, Ca or Fe phosphate precipitation. After leaching a greater volume of citrate through LVwf, P was still undetectable in effluents from columns, but there was an intensively leaching of Al and Fe, as well as changes in proportions of adsorbed P characterized in soil XANES spectra. Although we have found evidences about the action of main mechanisms of P solubilization (complexometric dissolution, and ligand exchange of carboxylic functional groups for adsorbed P on soil minerals) by LMWOA anions, they had a little potential to really increase P availability.
7

Dinâmica do fósforo no solo em função da adição de ácidos orgânicos de baixa massa molar / Phosphorus dynamics in soils amended with low molar mass organic acids

Sheila Renata Santos 16 February 2016 (has links)
A baixa eficiência da adubação fosfatada em solos altamente intemperizados é devido, entre outros fatores, à adsorção do fósforo (P) à superfície das argilas silicatadas do tipo 1:1 e, principalmente, dos (hidr)óxidos de Fe e de Al. Manejos do solo que induzem a solubilização de formas de P indisponíveis para as plantas têm sido intensamente estudados nos últimos anos. Uma tentativa de aumentar a concentração de P disponível na solução do solo para sua absorção pelas plantas é a mobilização de P por ânions de ácidos orgânicos de baixa massa molar (AOBMM). Ânions derivados de AOBMM exsudados pelas raízes de plantas ou excretados por microrganismos são associados com algumas condições de rizosfera como deficiência de P e fitotoxidez de Al e interagem com o solo de forma a aumentar a biodisponibilidade de P. Dependendo dos atributos do solo, do grau de dissociação, das propriedades e do número de grupos carboxílicos dos ânions orgânicos, o P pode ser mobilizado do solo principalmente devido à dissolução complexométrica de minerais e à adsorção competitiva dos grupos funcionais carboxílicos e fosfato nos sítios de superfície coloidais. A capacidade dos ânions citrato, malato e oxalato em mobilizar P de amostras de um Neossolo Quartzarênico típico (RQ) e de um Latossolo Vermelho ácrico (LVwf) foi avaliada por meio de um estudo de lixiviação de ânions em colunas. Devido a não detecção de P nos efluentes das colunas com LVwf, foi realizado outro estudo em colunas, no qual somente citrato foi lixiviado, mas num volume maior, e as alterações das formas de P nas amostras desse solo induzidas pela lixiviação de citrato foram identificadas por espectroscopia de absorção de raios-X na borda K do fósforo (X-ray absorption near edge structure -XANES - spectroscopy). A capacidade dos ânions de AOBMM em solubilizar P foi mais dependente do teor de P disponível e de outros atributos do solo que do número de grupos funcionais carboxílicos dos ânions orgânicos. Somente o oxalato mobilizou P do RQ, enquanto todos os ânions de AOBMM foram capazes de mobilizar P do LVwf. Quando baixos volumes de solução contendo ânions de AOBMM foram lixiviados no solo, além do aumento do pH, a mobilização de P foi acompanhada pela mobilização de Al no RQ (pH água = 5), e pela mobilização de Ca no LVwf (pH água = 5.6), o que indica solubilização de P pela complexação de Al, Ca, ou Fe, de fosfatos insolúveis, ou pela inibição da precipitação de P com esses metais. Ao lixiviar um volume maior de citrato no LVwf, o P também não foi detectado nos efluentes das colunas, mas houve lixiviação intensa de Al e Fe, bem como mudanças nas proporções de formas de P no solo caracterizadas pelos espectros XANES. Embora tenhamos encontrado indícios da ação dos principais mecanismos de solubilização de P (dissolução complexométrica de minerais e troca de ligantes entre grupos funcionais carboxílicos e P adsorvido ao solo), os ânions de AOBMM mostraram pouco potencial de efetivamente aumentar a biodisponibilidade de P. / Phosphate fertilization of acidic, highly weathered soils is inefficient because of the adsorption of phosphorus (P) to 1:1 silicate clays and, especially, to Fe and Al oxides. Different soil management practices to induce solubilization of unavailable forms of P to plants nutrition have been intensively studied in recent years. The mobilization of P with anions of low molecular weight organic acids (LMWOA) increases the concentration of available P in the soil solution for plant uptake. Anions derived from LMWOA exudates from plants root or excreted by microbes are associated with some rhizosphere conditions, as deficiency of P and Al phytotoxicity, and they interact with the soil in order to increase P availability. Depending on the soil attributes, and degree of dissociation, properties, and number of carboxyl groups from organic anions, P can be mobilized from soil mainly because of complexometric dissolution of soil minerals and ligand exchange of functional carboxyl groups and P adsorbed in soil surface sites. The capacity of citrate, malate and oxalate anions to mobilize P from a Typic Quartzipsamment (RQ) and an Anionic Acrudox (LVwf) was evaluated in a column leaching study. Because no P was detectable in columns effluents from LVwf, another column leaching study was performed, but only citrate was leached with a greater volume of solution, and citrate-induced changes at P forms in the soil were identified by P K-edge X-ray absorption near edge structure - XANES - spectroscopy. The capacity of LMWOA anions to solubilize P was more dependent of P status and other soil attributes, than number of carboxyl groups of organic anions. Only oxalate mobilized P from RQ, and all LMWOA anions were able to mobilize P from LVwf. Increasing of P mobilization and soil pH were followed by increases of Al mobilization from RQ (pH water = 5), and Ca mobilization from LVwf (pH water = 5.6) at lower volumes of LMWOA anions leaching. Phosphorus was solubilized by complexation of Al, Ca or Fe from insoluble phosphate minerals, or by inhibition of Al, Ca or Fe phosphate precipitation. After leaching a greater volume of citrate through LVwf, P was still undetectable in effluents from columns, but there was an intensively leaching of Al and Fe, as well as changes in proportions of adsorbed P characterized in soil XANES spectra. Although we have found evidences about the action of main mechanisms of P solubilization (complexometric dissolution, and ligand exchange of carboxylic functional groups for adsorbed P on soil minerals) by LMWOA anions, they had a little potential to really increase P availability.
8

Comportamento ambiental de sulfadiazina em solos brasileiros / Environmental behavior of sulfadiazine in brazilian soils

Marina Yasbek Reia 16 May 2013 (has links)
A manutenção da qualidade do solo como um recurso natural vital à humanidade tem impulsionado a pesquisa sobre a dinâmica ambiental de resíduos de antibióticos veterinários no ambiente. Os processos de sorção, degradação e lixiviação da sulfadiazina (SDZ) foram avaliados em quatro solos com atributos físico-químicos distintos, conforme o uso de técnicas radiométricas e os protocolos da OECD para pesticidas. Os coeficientes de sorção (Kd) da SDZ variaram de baixo a muito alto (2,6 a 80 L kg-1). O seu baixo potencial de dessorção (< 24,2% do sorvido ou < 12,1% do aplicado) ratifica a existência de mecanismos específicos envolvidos na sorção da SDZ, afora as interações eletrostáticas e a partição hidrofóbica apontadas pelos estudos prévios. Em concentrações residuais próximas às encontradas em campo (??84 ?g kg-1), o potencial de sorção da SDZ foi consideravelmente maior do que em altas concentrações. A dissipação da SDZ foi rápida em todos os solos (t1/2 < 2,7 dias) e a formação de resíduos ligados foi a principal via de dissipação, correspondendo a > 78% do aplicado após 7 dias. A taxa média de mineralização foi < 3% do aplicado. A presença do antibiótico não impactou a biomassa do solo, indicando que em doses crônicas os efeitos sejam imperceptíveis em curto prazo. Apesar do potencial de mobilidade, a SDZ apresentou baixo potencial de lixiviação nos solos (< 0,11% do aplicado). Já a redistribuição da SDZ foi maior no perfil dos solos recém-aplicados do que nos envelhecidos e a grande maioria permaneceu nos primeiros 5 cm (> 95 % do aplicado). Nos solos envelhecidos, a sua mobilidade foi praticamente nula (0,06% do aplicado). Os resultados da pesquisa contribuem para elucidar a dinâmica de contaminantes orgânicos em solos intemperizados e ácidos de regiões tropicais, o que poderá auxiliar modelos de avaliações de risco, ações de mitigação, entre outros. / The soil quality as a vital resource for humanity has driven research on the occurrence, environmental fate and behavior of antibiotic residues in the environment. Sorption, leaching and degradation tests were performed on four soils with distinct physic-chemical attributes with 14C-sulfadiazine, following guidelines developed by OECD (USA) for laboratory studies. As the development of research on the subject has its origins in temperate countries, the soil and climatic conditions occurring in the tropics resulted in variations in the dynamic of sulfadiazine, mainly due to conditions of weathered and acidize.The results showed higher Kd (from 3, 5 to 80 L kg-1) for the residual concentration detected in monitoring studies, rapid dissipation (DT 50 between 2 and 3 days) and reduced leaching potential, in contrast with rates reported in the literature. The formation of bound residues was the major route of dissipation in all soils, reaching values between 78 % and 89 % of the total in just 7 days, whereas the mineralization did not exceed 1.5% throughout the experiment. The analysis of the variation of microbial-biomass carbon as an negative effect of antibiotic, present no difference with the content in the control, as reported by several studies that argue that the effects of chronic doses are imperceptible in short term. Although the knowledge about processes transformation of organic chemicals in soils is very divergent, laboratory tests contributed to a first elucidation about environmental of antibiotic residues, contributing to the improved performance of models to compose risk assessments and mitigation actions in tropical soils, for example.
9

EFEITOS DO EXERCÍCIO RESISTIDO NA FASE HOSPITALAR DO PÓS-OPERATÓRIO DE REVASCULARIZAÇÃO DO MIOCÁDIO / EFFECTS OF WEATHERED EXERCISE IN THE HOSPITALAR PHASE OF POSTOPERATIVE OF THE MIOCÁDIO REVASCULARIZATION

Ximenes, Nayana Nazaré Pessoa Sousa 21 November 2014 (has links)
Made available in DSpace on 2016-08-19T18:15:54Z (GMT). No. of bitstreams: 1 Dissertacao NAYANA NAZARE PESSOA SOUSA XIMENES.pdf: 1995028 bytes, checksum: 3ae92b8f1b5e63655e1c2d926c972116 (MD5) Previous issue date: 2014-11-21 / Regular physical activity has been beneficial post - cardiac surgery. Early resistance exercise training improves functional capacity, clinical status, cardiac function and survival of patients, leading to a reduction of the harmful effects of prolonged bed rest, reduced care costs and hospital stay. Objective: To evaluate the effects of resistance exercise during hospital postoperative coronary artery bypass grafting (CABG). Methods: It was performed a randomized controlled trial with 37 patients subjected to isolated CABG between August 2013 and May 2014, distributed by simple drawing into two groups: control group (n = 20) that received conventional physiotherapy and intervention group (n = 17) underwent resistance exercise. Pulmonary function and functional capacity were assessed preoperatively, on discharge from the intensive care unit (ICU) and hospital discharge by spirometry and six minute walk test (6MWT). For statistical analyze were utilized Shapiro-Wilk, Mann-Whitney, Student's t, Fisher and G tests. Variables with p < 0.05 were considered significant. Results: The groups were homogeneous in terms of demographic, clinical, and surgical variables. No effect of resistance exercise on pulmonary function was observed when compared to control group. However, in intervention group it was maintained functional capacity during assessments periods when compared to the control group which was observed significant reducing (p < 0.0001). It was Observed a significant reduction in length of hospital stay (6.3 ± 1 2 vs. 7.6 ± 2.5 days) (p = 0.03). Conclusion: In this study, the resistance exercise during hospital CABG postoperative provided maintaining functional capacity and reduction of hospital stay when compared to conventional physiotherapy. / A prática de atividade física tem sido benéfica pós - cirurgia cardíaca. O exercício resistido precoce melhora a capacidade funcional, quadro clínico, função cardíaca e sobrevida dos pacientes, promovendo a diminuição dos efeitos prejudiciais do repouso prolongado no leito, redução dos custos com a assistência e tempo de internação hospitalar. Objetivo: avaliar os efeitos do exercício resistido na fase hospitalar do pós-operatório de revascularização do miocárdio (RM). Métodos: realizou-se um ensaio clínico controlado randomizado com 37 pacientes submetidos à RM isolada, com circulação extracorpórea entre agosto de 2013 e maio de 2014, distribuídos por sorteio simples em dois grupos: grupo controle (n = 20) que realizou fisioterapia convencional e grupo intervenção (n = 17) submetidos ao exercício resistido. A função pulmonar e a capacidade funcional foram avaliados no pré-operatório, alta da unidade de terapia intensiva (UTI) e alta hospitalar pela espirometria e teste de caminhada de seis minutos (TC6M). Para análise estatística empregaram-se os testes de Shapiro-Wilk, Mann-Whitney, t-Student, Fisher e G. variáveis com p < 0,05 foram consideradas significativas. Resultados: Os grupos apresentaram-se homogêneos quanto às variáveis demográficas, clínicas e cirúrgicas. Não se observou efeito do exercício resistido na função pulmonar quando comparado ao grupo controle. Entretanto, no grupo intervenção houve manutenção da capacidade funcional nos três períodos avaliados quando comparado ao grupo controle para o qual se observou queda significativa (p < 0,0001).Observou-se redução significativa do tempo de internação hospitalar (6,3 ± 1,2 vs. 7,6± 2,5 dias) , (p = 0,03) .Conclusão:No presente estudo, o exercício resistido na fase hospitalar do pós-operatório de RM proporcionou manutenção da capacidade funcional e redução do tempo de internação hospitalar quando comparado a fisioterapia convencional.
10

Geotechnical Investigations of Wind Turbine Foundations Using Multichannel Analysis of Surface Waves (MASW)

Hicks, Malcolm Andrew January 2011 (has links)
The geophysical technique known as Multichannel Analysis of Surface Waves, or MASW (Park et al., 1999) is a relatively new seismic characterisation method which utilises Rayleigh waves propagation. With MASW, the frequency dependent, planar travelling Rayleigh waves are created by a seismic source and then measured by an array of geophone receivers. The recorded data is used to image characteristics of the subsurface. This thesis explains how MASW was used as a geotechnical investigation tool on windfarms in the lower North Island, New Zealand, to determine the stiffness of the subsurface at each wind turbine site. Shear‐wave velocity (VS) profiles at each site were determined through the processing of the MASW data, which were then used to determine physical properties of the underlying, weathered greywacke. The primary research site, the Te Rere Hau Windfarm in the Tararua Ranges of the North Island, is situated within the Esk Head Belt of Torlesse greywacke (Lee & Begg, 2002). Due to the high level of tectonic activity in the area, along with the high rates of weathering, the greywacke material onsite is highly fractured and weathering grades vary significantly, both vertically and laterally. MASW was performed to characterise the physical properties at each turbine site through the weathering profile. The final dataset included 1‐dimensional MASW shear‐wave evaluations from 100 turbine sites. In addition, Poisson’s ratio and density values were characterised through the weathering profile for the weathered greywacke. During the geotechnical foundation design at the Te Rere Hau Windfarm site, a method of converting shear wave velocity profiles was utilised. MASW surveying was used to determine VS profiles with depth, which were converted to elastic modulus profiles, with the input parameters of Poisson’s ratio and density. This study focuses on refining and improving the current method used for calculating elastic modulus values from shear‐wave velocities, primarily by improving the accuracy of the input parameters used in the calculation. Through the analysis of both geotechnical and geophysical data, the significant influence of overburden pressure, or depth, on the shear wave velocity was identified. Through each of the weathering grades, there was a non‐linear increase in shear wave velocity with depth. This highlights the need for overburden pressure conditions to be considered before assigning characteristic shear wave velocity values to different lithologies. Further to the dataset analysis of geotechnical and geophysical information, a multiple variant non‐linear regression analysis was performed on the three variables of shear wave velocity, depth and weathering grade. This produced a predictive equation for determining shear wave velocity within the Esk Head belt ‘greywacke’ when depth and weathering data are known. If the insitu geological conditions are not comparable to that of the windfarm sites in this study, a set of guidelines have been developed, detailing the most efficient and cost effective method of using MASW surveying to calculate the elastic modulus through the depth profile of an investigation site.

Page generated in 0.0567 seconds