42 resultados para capacidade tampão do enxofre lábil
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The introduction of new digital services in the cellular networks, in transmission rates each time more raised, has stimulated recent research that comes studying ways to increase the data communication capacity and to reduce the delays in forward and reverse links of third generation WCDMA systems. These studies have resulted in new standards, known as 3.5G, published by 3GPP group, for the evolution of the third generation of the cellular systems. In this Masters Thesis the performance of a 3G WCDMA system, with diverse base stations and thousand of users is developed with assists of the planning tool NPSW. Moreover the performance of the 3.5G techniques hybrid automatic retransmission and multi-user detection with interference cancellation, candidates for enhance the WCDMA uplink capacity, is verified by means of computational simulations in Matlab of the increase of the data communication capacity and the reduction of the delays in the retransmission of packages of information
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Structures capable of absorbing large amounts of energy are of great interest, particularly for the automotive and aviation industries, to reduce tbe impact on passengers in the case of a collision. The energy absorption properties of composite materials structures can be tailored, thus making these structures an appealing option a substitute of more traditional structures in applications where energy absorption is crucial. ln this research, the influence of some parameters, which affect the energy absorption capacity of composite material tubes, was investigated. The tubes were fabricated by hand lay-up, using orthophthalic polyester resin and a plain weave E-glass fabric Test specimens were prepared and tested under compression load. The ínfluence of the following parameters on the specific energy absorption capacity of the tubes was studied: fiber configuration (0/90º or ± 45°), tube cross-section (circular or square), and processing conditions (with or without vacuum). The results indicated that circular cross-section tubes with fibers oriented at 0/90º presented the highest level of specific energy absorbed. Further, specimens from tubes fabricated under vacuum displayed higher energy absorption capacity, when compared with specimens from tubes fabricated without vacuum. Thus, it can be concluded that the fabrication process with vacuum produce composite structures with better energy absorption capacity
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This work depicts a study of the adsorption of carbon dioxide on zeolite 13X. The activities were divided into four stages: study batch adsorption capacity of the adsorbent with synthetic CO2 (4%), fixed bed dynamic evaluation with the commercial mixture of gases (4% CO2, 1.11% CO, 1 2% H2, 0.233% CH4, 0.1% C3, 0.0233% C4 argon as inert closing balance), fixed bed dynamic modeling and evaluation of the breakthrough curve of CO2 originated from the pyrolysis of sewage sludge. The sewage sludge and the adsorbent were characterized by analysis TG / DTA, SEM, XRF and BET. Adsorption studies were carried out under the following operating conditions: temperature 40 °C (for the pyrolysis of the sludge T = 600 °C), pressures of 0.55 to 5.05 bar (batch process), flow rate of the gaseous mixture between 50 - 72 ml/min and the adsorbent masses of 10, 15 and 20 g (fixed bed process). The time for the adsorption batch was 7 h and on the fixed bed was around 180 min. The results of this study showed that in batch adsorption process step with zeolite 13X is efficient and the mass of adsorbed CO2 increases with the increases pressure, decreases with temperature increases and rises due the increase of activation temperature adsorbent. In the batch process were evaluated the breakthrough curves, which were compared with adsorption isotherms represented by the models of Langmuir, Freündlich and Toth. All models well adjusted to the experimental points, but the Langmuir model was chosen in view of its use in the dynamic model does not have implications for adsorption (indeterminacy and larger number of parameters such as occurred with others) in solving the equation. In the fixed bed dynamic study with the synthetic gas mixture, 20 g of mass adsorbent showed the maximum adsorption percentage 46.7% at 40 °C temperature and 50 mL/min of flow rate. The model was satisfactorily fitted to the three breakthrough curves and the parameters were: axial dispersion coefficient (0.0165 dm2/min), effective diffusivity inside the particle (dm2/min 0.0884) and external transfer coefficient mass (0.45 dm/min). The breakthrough curve for CO2 in the process of pyrolysis of the sludge showed a fast saturation with traces of aerosols presents in the gas phase into the fixed bed under the reaction process
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Discussions about pollution caused by vehicles emission are old and have been developed along the years. The search for cleaner technologies and frequent weather alterations have been inducing industries and government organizations to impose limits much more rigorous to the contaminant content in fuels, which have an direct impact in atmospheric emissions. Nowadays, the quality of fuels, in relation to the sulfur content, is carried out through the process of hydrodesulfurization. Adsorption processes also represent an interesting alternative route to the removal of sulfur content. Both processes are simpler and operate to atmospheric temperatures and pressures. This work studies the synthesis and characterization of aluminophosphate impregnate with zinc, molybdenum or both, and its application in the sulfur removal from the gasoline through the adsorption process, using a pattern gasoline containing isooctane and thiophene. The adsorbents were characterized by x-ray diffraction, differential thermal analysis (DTG), x-ray fluorescence and scanning electron microscopy (SEM). The specific area, volume and pore diameter were determined by BET (Brunauer- Emmet-Teller) and the t-plot method. The sulfur was quantified by elementary analysis using ANTEK 9000 NS. The adsorption process was evaluated as function of the temperature variation and initial sulfur content through the adsorption isotherm and its thermodynamic parameters. The parameters of entropy (ΔS), enthalpy variation (ΔH) and free Gibbs energy (ΔG) were calculated through the graph ln(Kd) versus 1/T. Langmuir, Freundlich and Langmuir-Freundlich models were adjusted to the experimental data, and the last one had presented better results. The thermodynamic tests were accomplished in different temperatures, such as 30, 40 and 50ºC, where it was concluded the adsorption process is spontaneous and exothermic. The kinetic of adsorption was studied by 24 h and it showed that the capability adsorption to the adsorbents studied respect the following order: MoZnPO > MoPO > ZnPO > AlPO. The maximum adsorption capacity was 4.91 mg/g for MoZnPO with an adsorption efficiency of 49%.
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The restriction of physical fitness is directly related with hypertension and sleep disorders, while the respiratory muscle strength is associated with hypertension, but the literature is scarce regarding its relationship with sleep disorders and particularly with excessive daytime sleepiness. Objectives: To compare physical fitness and strength of respiratory muscles between people with hypertension with excessive daytime sleepiness (EDS) and non EDS people, those who do not feel excessive daytime sleepiness, in addition to relate aerobics resistance and functional mobility of patients. Methods: An observational, analytical and transversal study, evaluated 32 elderly with hypertension, divided into two groups (EDS and non EDS), in which the following topics were measured; respiratory muscular strength, functional fitness, level of physical activity, level of excessive daytime sleepiness, quality of sleep and intensity of the patients snoring. Results: There was a significant difference in the level of EDS (P=0,00) and quality of sleep (p=0,03), however, the data related to snoring intensity (p=0,18), maximum inspiratory pressure PImax (p=0,39) and maximum expiratory pressure PEmax (p=0,98) did not show any difference. Also, no significant difference was observed concerning physical fitness, presenting p=0,08 for the sitting and getting up test on the chair in 30 ; p=0,54 for the extension and flexing of the elbow test in 30 ; p=0,38 for the walking test 6 ; p=0,38 for the parking gear test 2 , p=0,08 for the sitting and reaching test; p=0,42 for the scratching the back test; p=0,49 for the getting up and walking test; and p=0,62 for the global rate of activity limitation. There was moderate positive correlation between 6MWT and 2MST, r=0,54 (p=0,01) and negative moderate correlation between 6MWT and TUG, r=-0,61 (p=0,000) and between 2MST and TUG, r=-0,60 (p=0,000). Conclusion: The presence of EDS in the hypertension people studied, showed a bad quality of sleep, however this sleepiness did not influence the strength of the respiratory muscles. The physical fitness came out diminished in all hypertension people, regardless of the presence or non presence of sleep disturbance; and there is a close relationship between cardiovascular resistance and physical mobility, since when there is less cardiovascular resistance, there is precarious physical mobility and vice-versa
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Introduction: The ability to walk is impaired in obese by anthropometric factors (BMI and height), musculoskeletal pain and level of inactivity. Little is known about the influence of body adiposity and the acute response of the cardiovascular system during whole the 6-minute walk test (6mWT). Objective: To evaluate the effect of anthropometric measures (BMI and WHR waist-to-hip ratio), the effort heart and inactivity in ability to walk the morbidly obese. Materials and Methods: a total 36 morbidly obese (36.23 + 11.82 years old, BMI 49.16 kg/m2) were recruited from outpatient department of treatment of obesity and bariatric surgery in University Hospital Onofre Lopes and anthropometric measurements of obesity (BMI and WHR), pulmonary function, pattern habitual physical activity (Baecke Questionnaire) and walking capacity (6mWT). The patient was checking to measure: heart rate (HR), breathing frequency (BF), peripheral oxygen saturation, level of perceived exertion, systemic arterial pressure and duplo-produto (DP), moreover the average speed development and total distance walking. The data were analysed between gender and pattern of body adiposity, measuring the behavior minute by minute of walking. The Pearson and Spearmam correlation coefficients were calculated, and stepwise multiple Regression examined the predictors of walking capacity. All analyses were performed en software Statistic 6.0. Results: 20 obese patients had abdominal adiposity (WHR = 1.01), waist circumference was 135.8 cm in women (25) and 139.8 cm in men (10). Walked to the end of 6mWT 412.43 m, with no differences between gender and adiposity. The total distance walked by obesity alone was explained by BMI (45%), HR in the sixth minute (43%), the Baecke (24%) and fatigue (-23%). 88.6% of obese (31) performed the test above 60% of maximal HR, while the peak HR achieved at 5-minute of 6mWT. Systemic arterial pressure and DP rised after walking, but with no differences between gender and adiposity. Conclusion: The walk of obese didn´t suffers influence of gender or the pattern of body adiposity. The final distance walked is attributed to excess body weight, stress heart, the feeling of effort required by physical activity and level of sedentary to obese. With a minute of walking, the obeses achieved a range of intensity cardiovascular trainning
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The results of studies about the ideal resistance training intensity for reduction of resting blood pressure levels, as well as this type of training to increase the functional capacity of hypertensive older women are still unclear, since the few investigations usually analyze young individuals normotensive, and the literature lacks precise information in elderly hypertensive subjects. Objectives: To determine the effect of two resistance training intensities on resting blood pressure and the effect of resistance training on functional capacity in elderly women with systemic arterial hypertension, analyzing these variables before and after eight weeks of intervention. Methods: Patients underwent eight weeks of resistance training, with a frequency of three times per week on alternate days, in the afternoon. The exercises performed were: leg press, bench press, knee extension, lat pull-down, knee flexion, shoulder abduction, standing cable hip abduction and biceps curl. Results: It was found that patients who underwent training with moderate resistance, showed a reduction on resting values of diastolic blood pressure (DBP) p<0.03 and of mean arterial pressure (MAP) p<0.03. Patients who underwent mild resistance training showed reduction in resting values of MAP (p<0.03) and a tendency to decrease in DBP (p<0.06). With regard to functional capacity, the results showed significant increase in the strength of arms and legs, agility and aerobic endurance (p<0.001) and maintaining flexibility (p>0.05). Conclusion: The data indicated that both mild and moderate resistance training, even when started in old age, promoted cardiovascular benefits and also improve the functional capacity of hypertensive older women.
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Morbidly obese patients present an increase in heart rate, blood pressure and perceived exertion besides lower walking ability compared to normal weight people. However, little is known about how these variables are presented after bariatric surgery. Moreover, despite the distance walked during the six-minute walk (6MWT) improve after surgery is not well established if the level of physical activity influences this improvement. Objective: To evaluate cardiovascular performance, perceived effort, ability of walking and physical activity level of patients with morbid obesity before and after bariatric surgery. Methods: The cardiovascular performance, perception of effort, the ability to walk and level of physical activity were assessed in 22 patients before (BMI = 50.4 kg/m2) and after (BMI = 34.8 kg/m2) bariatric surgery through the 6MWT. The heart rate, blood pressure and perceived exertion were assessed at rest, at the end of the 6MWT and in the second minute post-test (HR recovery). The ability to walk was measured by total distance walked at the end of the test while the level of physical activity was estimated by applying the Baecke questionnaire, analyzing domains occupation, leisure and locomotion and leisure and physical activity. Results: The HR at rest and recovery decreased significantly (91.2 ± 15.8 bpm vs. 71.9 ± 9.8 bpm, 99.5 ± 15.3 bpm vs 82.5 ± 11.1 bpm, respectively), as well as all the arterial pressure and perceived exertion after surgery. The distance achieved by the patients increased by 58.4 m (p = 0.001) postoperatively. Time postoperatively had correlation with the percentage of excess weight lost (r = 0.48, p = 0.02), BMI (r =- 0.68, p = 0.001) and the Baecke (r = 0.52, p = 0.01) which did not happen with the distance walked (r = 0.37, p = 0.09). Despite weight loss, patients showed no difference in the level of physical activity in any of the areas before and after surgery. Conclusion: The cardiovascular performance, the perception of effort and ability to walk seem to improve after bariatric surgery. However, despite improvement in the ability to walk by the distance achieved in the 6MWT after weight loss, this is not reflected in an increase in physical activity level of obese patients after surgery
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INTRODUCTION: Cardiac and pulmonary manifestations of the Chagas disease (CD) affect between 20-30% of the infected subjects. The chronic Chagas cardiomyopathy (CCC) has some peculiarities such as arrhythmias and, especially heart failure (HF) and is potentially lethal due to left ventricular dysfunction. How respiratory disorders, patients get progressive loss of functional capacity, which contributes to a poor quality of life related to disease. Measurements of lung volume by the movement of the chest wall surface are an alternative evaluation of lung function and kinematics of complex thoracoabdominal for these patients. OBJECTIVE: evaluate the kinematics of the thoracoabdominal complex through the regional pulmonary volumes and to correlate with functional evaluation of the cardiorrespiratory system in patients with Chagas disease at rest. MATERIALS AND METHODS: a cross-section study with 42 subjects had been divided in 3 groups, 15 composed for patients with CCC, 12 patients with HF of different etiologies and 15 healthful presented control group. An optoelectronic plethysmography (POE), Minnesota questionnaire, six minute walk test, spirometer and manovacuometer was used. RESULTS: It was observed in the 6MWT where group CRL presented greater distance 464,93±44,63m versus Group HF with 399,58± 32,1m (p=0,005) and group CCC 404±68,24m (p=0,015), both the groups presented difference statistics with regard to Group CRL. In the manovacuometer 54,59±19,98; of the group CCC and 42,11±13,52 of group IC found group CRL presented 81,31±15,25 of the predicted versus, presenting in relation to group CRL. In the POE it observed a major contribution in abdominal compartment in patients with IC if compared like CCC and control groups. On the basis of the questionnaire of quality of life of Minessota, verified a low one groups CCC and IC 43,2±15,2 and 44,4±13,1, respectively (p<0,05) when compared with the control group (19,6±17,31). CONCLUSION: it seems that the patients with CCC possess same functional and respiratory characteristics, observed for the POE, 6MWT, manovacuometer and spirometer to the patients of group HF, being able to consider similar interventions for this complementary group as therapeutical of this neglected disease
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Population aging is one of the greatest challenges to contemporary public health and, in this perspective, the functional capacity emerges as an important feature in geriatric assessment. The oral health of elderly, in turn, deserves special attention because, historically, in the dental services, this population group was not considered a priority for attention, which is verified by high rates of edentulism found even among these individuals. The present study proposes to examine the relationship between oral health status and functional capacity in an elderly population. To this end, intra-oral epidemiological examination was performed to assess the degree of dental caries, periodontal status, use and need of prosthesis and the presence of lesions. Functional capacity was assessed by the Independence in Activities of Daily Living, which considers the independence or not in the performance of six self-care functions. Socioeconomic and demographic characteristics and general health status were also investigated, in view of the possibility of intervention of these variables in the investigated relation. An factor analysis of the principal components was conducted which resulted four indicators of oral health conditions, representative of the population studied. 441 seniors were enrolled with mean age of 71.7 (± 8.7) years, the majority being female (68%). Functional capacity was dichotomized into completely independent individuals (89.6%) and dependent on at least one of the functions considered (10.4%). There was an association between functional capacity and the indicators related to the presence of many teeth and dental caries, and to that associated with the use and need of prostheses. These associations in turn, lost statistical significance when adjusting for confounding variables, combined in separate models for each indicator. Some of these variables, however, remained associated with functional capacity. It is considered that the study of oral health status of elderly, associeted with the search for an association with functional capacity is important in the construction of indicators necessary for planning preventive and therapeutic interventions that reduce the risk for loss of ability in daily physical functions and their consequences, as the harm in the oral self-care
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Central Nervous System are the most common pediatric solid tumors. 60% of these tumors arise in posterior fossa, mainly in cerebellum. The first therapeutic approach is surgical resection. Malignant tumors require additional strategies - chemotherapy and radiotherapy. The increasing survival evidences that childhood brain tumors result in academic and social difficulties that compromise the quality of life of the patients. This study investigated the intellectual functioning of children between 7 to 15 years diagnosed with posterior fossa tumors and treated at CEHOPE - Recife / PE. 21 children were eligible - including 13 children with pilocytic astrocytoma (G1) who underwent only surgery resection, and eight children with medulloblastoma (G2) - submitted to surgical resection, chemotherapy and craniospinal radiotherapy. Participants were evaluated by the Wechsler Intelligence Scale for Children - WISC-III. Children of G1 scored better than children of G2. Inferential tools (Mann-Whitney Ü Test) identified significant diferences (p ≤ 0.05) between the Performance IQ (PIQ) and Processing Speed Index (PSI) as a function of treatment modality; Full Scale IQ (FSIQ), PIQ and PSI as a function of parental educational level; PIQ, FSIQ, IVP and Freedom from Distractibility (FDI) as a function of time between diagnosis and evaluation. These results showed the late and progressive impact of radiotherapy on white matter and information processing speed. Furthermore, children whose parents have higher educational level showed better intellectual performance, indicating the influence of xxii socio-cultural variables on cognitive development. The impact of cancer and its treatment on cognitive development and learning should not be underestimated. These results support the need to increase the understanding of such effects in order to propose therapeutic strategies which ensure that, in addition to the cure, the full development of children with this pathology
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In this work, chitosan was used as a coating of pure perlite in order to increase the accessibility of the groups OH- e NH2+the adsorptionof ions Mn2+ e Zn2+.The characterization results of the expanded perlite classified as microporous and whose surface area 3,176 m2 g-1after the change resulted in 4,664 m2g-1.From the thermogravimetry(TG) it was found that the percentage of coating was34,3%.The infrared analysis can prove the presence of groups Si-OH, Si-O e Al-O-Siresulting from the perlite and C=O, NH2and OH characterization of chitosan. The experiments on experiments on the adsorption of Mn and Zn were performed in the concentration range of10 a 50 mgL-1and the adsorption capacity inpH 5,8 e 5,2 was 19,49 and 23,09 mgg-1to 25 oC,respectively.The adsorption data were best fitted to Langmuir adsorption model to Langmuir adsorption model for both metalionsisindicative of monolayer adsorption. The kinetics of adsorption were calculated from the equation of Lagergren fitting the model pseudo-second-order for all initial concentrations, suggesting that adsorption of ions Mn2+ and Zn2+ follows the kinetics of pseudo-second-order and whose constant Speedk2(g/mg.min) are 0,105 e 3,98 and capacity and maximum removal qe 4,326 e 3,348,respectively.In this study we used a square wave voltammetry cathodic stripping voltammetry to quantify the adsorbed ions, and the working electrode glassy carbon, reference electrode silver / silver chloride and a platinum auxiliary electrode. The attainment of the peaks corresponding to ions Mn2+ and Zn2+ was evaluated in and electrochemical cell with a capacity of 30 mL using a buffer system (Na2HPO4/NaH2PO4)at pH 4 and was adjusted with solutionsH3PO4 0,1molL-1and NaOH 0,1 molL-1and addition of the analyte has been a cathodic peak in- 0,873 Vand detection limit of2,55x10-6molL-1para Zn.The dough used for obtaining the adsorption isotherm was 150 mg and reached in 120 min time of equilibrium for both metal ions.The maximum adsorption for 120 min with Mn concentration 20 mgL-1 and Zn 10 mgL-1,was91, 09 e 94, 34%, respectively
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The underground natural gas found associated or not with oil is characterized by a mixture of hydrocarbons and residual components such as carbon dioxide (CO2), nitrogen gas (N2) and hydrogen sulfide (H2S), called contaminants. The H2S especially promotes itself as a contaminant of natural gas to be associated with corrosion of pipelines, to human toxicity and final applications of Natural Gas (NG). The sulfur present in the GN must be fully or partially removed in order to meet the market specifications, security, transport or further processing. There are distinct and varied methods of desulfurization of natural gas processing units used in Natural Gas (UPGN). In order to solve these problems have for example the caustic washing, absorption, the use of membranes and adsorption processes is costly and great expenditure of energy. Arises on such findings, the need for research to active processes of economic feasibility and efficiency. This work promoted the study of the adsorption of sulfide gas in polymer matrices hydrogen pure and modified. The substrates of Poly(vinyl chloride) (PVC), poly(methyl methacrylate) (PMMA) and sodium alginate (NaALG) were coated with vanadyl phosphate compounds (VOPO4.2H2O), vanadium pentoxide (V2O5), rhodamine B (C28H31N2O3Cl) and ions Co2+ and Cu2+, aiming to the adsorption of hydrogen sulfide gas (H2S). The adsorption tests were through a continuous flow of H2S in a column system (fixed bed reactor) adsorption on a laboratory scale. The techniques used to characterize the adsorbents were Infrared spectroscopy (FTIR), thermogravimetry analysis (TGA), X-ray fluorescence (XRF), the X-ray diffraction (XRD) electron microscopy (SEM). Such work indicates, the results obtained, the adsorbents modified PMMA, PVC and NaALG have a significant adsorptive capacity. The matrix that stood out and had the best adsorption capacity, was to ALG modified Co2+ with a score of 12.79 mg H2S / g matrix
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Intensive production of tilápias, in cages or net tanks, has been proposed as an alternative to increase fish production, that would generate income and offer animal protein in different tropical and subtropical countries. However, this system of production enriches the aquatic environment with nutrients, principally nitrogen and phosphor derived from the dejections of the metabolism of food and eventual food surpluses consumed by the fishes; the alimentation of the fishes in this production modality is dependent on fish food. The emission of these nutritions in levels above the limit that the system is capable metabolize can provoke a phenomenon called eutrofization, putting in risk the quality of water for public and for fish production activities. In this context the work had as a goal to evaluate the trófico state of the four reservoirs for intensive production of tilapias in net-tanks, in other words, he maximum fish production that the reservoirs are able to hold, keeping the desired quantity of nutrient concentrations in water for public use. The results of the four ecosystems in the Boqueirão de Parelhas reservoir showed that it s possible to have an intensive production of tilapias in net tanks, in this environment the annual average concentration of phosphor, was below the considered critical limits to deflagrate the process of eutrofization in semi-arid regions. The carrying capacity of the Boqueirão de Parelhas reservoir depends on the conversion of the feeding facts and phosphor content in the food but it should vary between 100 and 300 tons per year over a variation in the conversion feeding factor of 1,7 to 2,0:1 and a variation in the P in the food of 0,7 to 0,9%
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One of the main problems related to the use of diesel as fuel is the presence of sulfur (S) which causes environmental pollution and corrosion of engines. In order to minimize the consequences of the release of this pollutant, Brazilian law established maximum sulfur content that diesel fuel may have. To meet these requirements, diesel with a maximum sulfur concentration equal to 10 mg/kg (S10) has been widely marketed in the country. However, the reduction of sulfur can lead to changes in the physicochemical properties of the fuel, which are essential for the performance of road vehicles. This work aims to identify the main changes in the physicochemical properties of diesel fuel and how they are related to reduction of sulfur content. Samples of diesel types S10, S500 and S1800 were tested according with the methods of the American Society for Testing and Materials (ASTM). The fuels were also characterized by thermogravimetric analysis (TG) and subjected to physical distillation (ASTM D86) and simulated distillation gas chromatography (ASTM D2887). The results showed that the reduction of sulfur turned the fuel lighter and fluid, allowing a greater applicability to low temperature environments and safer for transportation and storage. Through the simulated distillation data was observed that decreasing sulfur content resulted in higher initial boiling point temperatures and the decreasing of the boiling temperature of the medium and heavy fractions. Thermogravimetric analysis showed a loss event mass attributed to volatilization or distillation of light and medium hydrocarbons. Based on these data, the kinetic behavior of the samples was investigated and it was observed that the activation energies (Ea) did not show significant changes throughout conversion. Considering the average of these energies, the S1800 had the highest Ea during the conversion and the S10 the lowest values