Síntese enzimática de ésteres de açúcar: surfactantes e polímeros como novos materiais ambientalmente seguros

Sugar esters are substances which possess surfactant, antifungical and bactericidal actions and can be obtained through two renewable sources of raw materials: sugars and vegetable oils. Their excellent biodegradability, allied to lhe fact that they are non toxic, insipid, inodorous, biocompatible, no-ionic, digestible and because they can resist to adverse conditions of temperature, pH and salinity, explain lhe crescent use of these substances in several sections of lhe industry. The objective of this thesis was to synthesize and characterize surfactants and polymers containing sugar branched in their structures, through enzymatic transesterification of vinyl esters and sugars, using alkaline protease from Bacillus subtilis as catalyst, in organic medium (DMF).Three types of sugars were used: L-arabinose, D-glucose and sucrose and two types of vinyl esters: vinyl laurate and vinyl adipate. Aiming to reach high conversions from substrates to products for a possible future large scale industrial production, a serie of variables was optimized, through Design of Experiments (DOE), using Response Surface Methodology (RSM).The investigated variables were: (1) enzyme concentration; (2) molar reason of substrates; (3) water/solvent rale; (4) temperature and (5) time. We obtained six distinct sugar esters: 5-0-lauroyl L-arabinose, 6-0-lauroyl D-glucose, 1'-O-lauroyl sucrose, 5-0-vinyladipoyl L-arabinose, 6-0-vinyladipoyl D-glucose and 1 '-O-vinyladipoyl sucrose, being lhe last three polymerizable. The progress of lhe reaction was monitored by HPLC analysis, through lhe decrease of sugar concentration in comparison to lhe blank. Qualitative analysis by TLC confirmed lhe formation of lhe products. In lhe purification step, two methodologies were adopted: (1) chromatographic column and (2) extraction with hot acetone. The acylation position and lhe chemical structure were determined by 13C-RMN. The polymerization of lhe three vinyl sugar esters was possible, through chemical catalysis, using H2O2 and K2S2O8 as initiators, at 60°C, for 24 hours. IR spectra of lhe monomers and respective polymers were compared revealing lhe disappearance of lhe vinyl group in lhe polymer spectra. The molar weights of lhe polymers were determined by GPC and presented lhe following results: poly (5-0-vinyladipoyl L-arabinose): Mw = 7.2 X 104; PD = 2.48; poly (6-0-vinyladipoyl D-glucose): Mw = 2.7 X 103; PD = 1.75 and poly (1'-O-vinyladipoyl sucrose): Mw = 4.2 X 104; PD = 6.57. The six sugar esters were submitted to superficial tension tests for determination of the critical micelle concentrations (CMC), which varied from 122 to 167 ppm. Finally, a study of applicability of these sugar esters, as lubricants for completion fluids of petroleum wells was' accomplished through comparative analysis of lhe efficiency of these sugar esters, in relation to three commercial lubricants. The products synthesized in this thesis presented equivalent or superior action to lhe tested commercial products

Decaimento bacteriano em lagoas de estabilização no Nordeste brasileiro

Stabilization pond system consisting in more sewage treatment used in Rio Grande do Norte (RN), Brazil, representing about 90% of all systems. Fecal bacteria are removed mainly facultative ponds and in maturation ponds. Many factors influence bacterial decay, such as the levels of pH and DO, temperature, light intensity, HDT and nutrient availability. The bacterial decay rate (Kb) is calculated considering many variables, but the hydraulic regime is a significant influence for microorganisms removal, and the dispersed flow which best characterizes a stabilization pond. However, some authors developed equations for the Kb accordant plug flow and complete mixing. This research study aimed to evaluate the bacterial decay of fecal coliform and Enterococcus sp. in stabilization ponds designed to treat domestic sewage, full-scale, in RN. All systems have assessed pretreatment, a facultative pond (LF) followed by two maturation (LM1 and LM2). The parameters availed were: temperature, pH, DO, BOD5, COD, fecal coliform, Enterococcus sp., Chlorophyll a, total suspended solids, fixed and volatile. In general, there were not significant differences for pH, DO and temperature in the ponds, except for the new systems, since they have low flow and hydraulic loads. The removal of organic matter in the ponds was low, about 70%, and nearly all are overloaded organic and operational problems. The bacterial removals were low, with average 96% for LF for fecal coliform, and 98% for Enterococcus sp.; LM1 were in itself a removal for fecal coliform about 71%, and 81% for Enterococcus sp.; LM2 have efficiency of 69% for fecal coliform, and 68% for Enterococcus sp. The equation proposed by Von Sperling (1999), according to the dispersed flow regime, generated empirical values of Kb more approximate to calculated values of Kb. On average, the calculated Kb to coliforms in the LF was 0.31 d-1, and for both maturation ponds were 0.35 d-1. For Enterococcus sp. the average was 0.40 d-1 for LF, 0.55 d-1 for LM1, and 0.58 d-1 for LM2. These results also showed that the Kb obtained in full-scale systems are smaller than those found in pilot-scale ponds. Moreover, one can say that the equation proposed by Marais (1974), according to the complete-mix regime, overestimates Kb. Actual results of Kb indicated that fecal coliforms are more resistant to adverse conditions present in stabilization ponds than Enterococcus sp., therefore, an indicator of microbiological safety and efficiency. The factors significant interventions in the rate of bacterial decay were concentrations of COD, the organic loading and HDT. The few Kb relationship between pH, DO and temperature were not significant. Finally, we conclude that it s essential to correct operation and maintenance, for not performing these activities is one of the main factors contributing to low rates of bacterial decay.

Variações horárias na entrada e saída dos golfinhos-rotadores e sua relação com fatores ambientais, na Baía dos Golfinhos em Fernando de Noronha PE

The dolphins are found in all world s marine environments, except for poles. On Brazil, the major concentration of this animals is on Fernando de Noronha Islands, wich have a tropical climate with two well-defined rainfall seasons: dry and rainy season. The Baía dos Golfinhos, wich is the most crowded piece of dolphins on the archipelago. These research looks for to characterize the circadian rhythms of the spinner dolphin behavior, Stenella longirostris, on the Baía dos Golfinhos occupation, at the Fernando de Noronha islands, Brazil s northeast, according to the fluctuations of environment that they all are inserted. The research was realized daily between 1991 January and 2009 December, with observations from a fixed point up to Mirante dos Golfinhos, located on Baía dos Golfinhos. The data was examined with the PASW Statistics 18 program, up to nonparametric tests, being analyzed on the incoming and out coming time of the spinner dolphins and the relationship with moon phases, the wind incidence, and the rainfall season, the dolphins were inserted. The spinner dolphins diurnal rhythms are influenced by moon phases, the spinner dolphins arrival at Baía dos Golfinhos earlier when it s full moon because of the high luminosity at night cause a bigger food efficiency for these animals. The outgoing time of spinner dolphins didn t show statistic difference between moon phases, despite follows the same pattern for the incoming time. When the spinner dolphins are submitted to bigger wind incidence conditions around the archipelago, the dolphins come early to the Baía dos Golfinhos, since that one is protected from wind that reaches Fernando de Noronha, the spinner dolphins tends to arrive later and leave earlier of the bay because the rain may cause adverse conditions for your rest.

O lugar do estudo das mídias na formação de professores numa perspectiva emancipatória

The media currently play a dual role in the physical and symbolic structure of social organization. It is through the media that companies have achieved control of their distribution and production. It is not only through the media, but mainly so, that certain world views circulate and are legitimized. Access to material and symbolic goods has become a mark of social distinction. The project of a more democratic society also involves the preparation of its citizens to be able both to deal with the media products that already circulate as well as to develop a critical perspective of media products. This research stemmed from the need to understand what place this study of the media occupies in training for teachers in early grades, given that children are already immersed in a media world from an early age. This research shows that this is a place which is under construction and despite the existing adverse conditions, emancipatory practices are being developed. The research is guided by the study of the media in teacher education from an emancipatory perspective. This perspective develops in a time that, in this case, has proved slow and fragmented, but not nonexistent. The process of teacher training is influenced by working conditions and educational policies that hinder both working with the media in school and also improving the critical understanding of the media. The research shows that training opportunities, even in these conditions, can allow for more meaningful criticism. The emancipatory perspective also includes a reflection on practices. These practices are being developed and this research sought to provide support for a proposed study of the media from this perspective

Estudo comparativo de estratégias de controle aplicadas a um gerador síncrono

The robustness and performance of the Variable Structure Adaptive Pole Placement Controller are evaluated in this work, where this controller is applied to control a synchronous generator connected to an infinite bus. The evaluation of the robustness of this controller will be accomplished through simulations, where the control algorithm was subjected to adverse conditions, such as: disturbances, parametric variations and unmodeled dynamic. It was also made a comparison of this control strategy with another one, using classic controllers. In the simulations, it is used a coupled model of the synchronous generator which variables have a high degree of coupling, in other words, if there is a change in the input variables of the generator, it will change all outputs simultaneously. The simulation results show which control strategy performs better and is more robust to disturbances, parametric variations and unmodeled dynamics for the control of Synchronous Generator

O laboratório de ensino de matemática temático centrado nos instrumentos de navegação: uma proposta para o IFRN de Mossoró-RN

This work presents a proposal to build a Mathematics Teaching Laboratory (MTL) whose main theme is the study, construction and use of instruments for navigation and location of mathematical content in an interdisciplinary way approach, and develop a notebook of activities focused on navigational instruments. For this it was necessary a literature review to understand the different conceptions of MTL and its pedagogical implications. The methodology used was literature research, construction and handling of instruments, and pedagogical experimentation. Lorenzato (2006) highlights the importance of an environment and suitable for a professional who can do a good job instruments. The implementation of an LEM can find some obstacles. The lack of support from other teachers or the management, the lack of a suitable place to store the materials produced, the lack of time in the workload of the teacher to prepare the lab activity, etc. Even in unfavorable or adverse conditions, according Lorenzato (2006), its implementation will benefit teachers and students. The lack of teacher training in their initial and continuing education, to use materials, and the lack of manuals with lab activities are also mentioned as factors that keep teachers from MTL. With propóposito assist the teacher of elementary or middle school in building a theme MTL prepared and we are providing a notebook of activities that provides a didactic sequence involving History and Mathematics. The book consists of four accompanied by suggestions for teachers activities, however the teacher has full autonomy to adapt the activities to the reality of your school. Among the instruments of navigation presented in this study chose to build the quadrant due to its simplicity, low cost of material and great teaching potential that this instrument has. But a theme lab is always being built and rebuilt as it is a research environment

Otimização dos parâmetros de um modelo de bomba em sistemas de bombeio centrífugo submerso

One of several techniques applied to production processes oil is the artificial lift, using equipment in order to reduce the bottom hole pressure, providing a pressure differential, resulting in a flow increase. The choice of the artificial lift method depends on a detailed analysis of the some factors, such as initial costs of installation, maintenance, and the existing conditions in the producing field. The Electrical Submersible Pumping method (ESP) appears to be quite efficient when the objective is to produce high liquid flow rates in both onshore and offshore environments, in adverse conditions of temperature and in the presence of viscous fluids. By definition, ESP is a method of artificial lift in which a subsurface electric motor transforms electrical into mechanical energy to trigger a centrifugal pump of multiple stages, composed of a rotating impeller (rotor) and a stationary diffuser (stator). The pump converts the mechanical energy of the engine into kinetic energy in the form of velocity, which pushes the fluid to the surface. The objective of this work is to implement the optimization method of the flexible polyhedron, known as Modified Simplex Method (MSM) applied to the study of the influence of the modification of the input and output parameters of the centrifugal pump impeller in the channel of a system ESP. In the use of the optimization method by changing the angular parameters of the pump, the resultant data applied to the simulations allowed to obtain optimized values of the Head (lift height), lossless efficiency and the power with differentiated results.

Análise das LER/DORT notificadas no Rio Grande do Norte de 2010 a 2014

The increasing prevalence of Repetitive Strain Injury / Work-Related Musculoskeletal Disorders (RSI / MSDs) has been explained by changes in the work that has been characterized by setting goals and productivity. This fact does not take into account the psycho-physiological characteristics of workers who become ill as a result of professional activities engaged in and also the adverse conditions in which his work was done. This study aimed to analyze the RSI / MSDs reported in the state of Rio Grande do Norte, Brazil, 2010-2014 compared to the profile of the population, epidemiological aspects and features of these diseases. It is a descriptive epidemiological cross-sectional study using secondary data obtained in the Notifiable Diseases Information System (SINAN) in May 2015 was used as the area covered by the Rio Grande do Norte. Data were collected regarding the grievances of work-related RSI / MSDs, assigned by the Worker's Health Reference Center (CEREST) of the State Health Department. Data were processed with the help of Microsoft Excel® 2013 and presented in tables in absolute frequency (n) and relative frequency (%). The results showed a total of 403 notifications of RSI / MSDs, where the vast majority 72% (290) was recorded in Natal. Regarding the profile of notified employees, 88.59% (357) have aged between 25 and 54 years, 62.78% (253) were female, and in relation to education, 31.51% (127) had high school complete. The most affected occupations were seamstresses (the clothing industry) with 24.97% (97), followed by masons, construction with 3.23% (13) and cashiers with 2.99% (12). About the work situation, 75.93% (306) had a formal contract, however, were sent to Communications Occupational accidents (CAT) only 67% (270) of the cases. Regarding the signs and symptoms, pain and limitation of movement were the most mentioned respectively with 98.01% (395) and 95.04% (383) of notifications. Notifications, 94.29% (380) showed exposure to repetitive movements in their workplace. The most frequent specific diagnoses were synovitis and tenosynovitis (CID F 65), with 30.02% (121) of notifications, followed by back pain (CID F 54) to 19.35% (78) and shoulder injuries (ICD M 75) with 15.88% (64). They were away from work 81.64% (329) of workers reported with RSI / MSDs. Evolution more prevalent among cases was temporary disability with 75.68% (305). It was concluded that the SINAN is a database of potential to characterize the profile of RSI / MSDs, requiring, however, an improvement in the coverage of records and data quality. In addition, this study reflects the need to implement protection strategies to workers by companies, signaling promotion, prevention and rehabilitation aimed at reducing these injuries and the improvement of occupational health indicators in Rio Grande do Norte.

Síntese enzimática de ésteres de açúcar: surfactantes e polímeros como novos materiais ambientalmente seguros

Sugar esters are substances which possess surfactant, antifungical and bactericidal actions and can be obtained through two renewable sources of raw materials: sugars and vegetable oils. Their excellent biodegradability, allied to lhe fact that they are non toxic, insipid, inodorous, biocompatible, no-ionic, digestible and because they can resist to adverse conditions of temperature, pH and salinity, explain lhe crescent use of these substances in several sections of lhe industry. The objective of this thesis was to synthesize and characterize surfactants and polymers containing sugar branched in their structures, through enzymatic transesterification of vinyl esters and sugars, using alkaline protease from Bacillus subtilis as catalyst, in organic medium (DMF).Three types of sugars were used: L-arabinose, D-glucose and sucrose and two types of vinyl esters: vinyl laurate and vinyl adipate. Aiming to reach high conversions from substrates to products for a possible future large scale industrial production, a serie of variables was optimized, through Design of Experiments (DOE), using Response Surface Methodology (RSM).The investigated variables were: (1) enzyme concentration; (2) molar reason of substrates; (3) water/solvent rale; (4) temperature and (5) time. We obtained six distinct sugar esters: 5-0-lauroyl L-arabinose, 6-0-lauroyl D-glucose, 1'-O-lauroyl sucrose, 5-0-vinyladipoyl L-arabinose, 6-0-vinyladipoyl D-glucose and 1 '-O-vinyladipoyl sucrose, being lhe last three polymerizable. The progress of lhe reaction was monitored by HPLC analysis, through lhe decrease of sugar concentration in comparison to lhe blank. Qualitative analysis by TLC confirmed lhe formation of lhe products. In lhe purification step, two methodologies were adopted: (1) chromatographic column and (2) extraction with hot acetone. The acylation position and lhe chemical structure were determined by 13C-RMN. The polymerization of lhe three vinyl sugar esters was possible, through chemical catalysis, using H2O2 and K2S2O8 as initiators, at 60°C, for 24 hours. IR spectra of lhe monomers and respective polymers were compared revealing lhe disappearance of lhe vinyl group in lhe polymer spectra. The molar weights of lhe polymers were determined by GPC and presented lhe following results: poly (5-0-vinyladipoyl L-arabinose): Mw = 7.2 X 104; PD = 2.48; poly (6-0-vinyladipoyl D-glucose): Mw = 2.7 X 103; PD = 1.75 and poly (1'-O-vinyladipoyl sucrose): Mw = 4.2 X 104; PD = 6.57. The six sugar esters were submitted to superficial tension tests for determination of the critical micelle concentrations (CMC), which varied from 122 to 167 ppm. Finally, a study of applicability of these sugar esters, as lubricants for completion fluids of petroleum wells was' accomplished through comparative analysis of lhe efficiency of these sugar esters, in relation to three commercial lubricants. The products synthesized in this thesis presented equivalent or superior action to lhe tested commercial products