Elaboração de uma unidade de ensino potencialmente significativa em Química para abordar a temática água

The evidence of the water theme in news reports is configured as an important topic of interest to contextualize, problematize and/or generate meaning in the midst of discussion of a content from different levels of education and/or disciplines of basic education. The possibilities to use this theme in classroom is also highlighted in Brazilian official documents that guide the practice of teachers of all Brazilian curricular components of this educational level. So, the theme water can be used as subsidy to teach chemistry, since contextualises the teaching of this discipline aiding in the discussion of different chemical concepts. In this perspective, the meaningful learning theory, developed by David Ausubel, has constructivist nature and says that an individual learns significantly when he can relate new information with a specific knowledge structure that integrates the prior knowledge of its structure. In this sense, the use of water as a theme for the approach prior knowledge of chemical concepts has already been characterized as an important topic that can give meaning to the content of education in chemistry. In this dissertation, a teaching unit potentially significant (TUPS) is presented based on meaningful learning theory of David Ausubel approaching the theme water. approaching the theme water. The unit was used in a class of thirty-five students of the 2nd year of high school, a public school in the city of Extremoz-RN, metropolitan region of Natal / RN. Through it was possible to discuss an issue of interest to students of the school to address the chemical contents, such as solutions, physicochemical aspects and stages of water treatment. At first, an initial questionnaire was used to identify the students' previous ideas on the topic under study to the concept of chemical solutions. It was subsequently developed and implemented a series of activities based on students' ideas. To subsidize the sequence, it was prepared four booklets that worked the content of chemical solutions, contextualizing the theme water. The results of this work showed that the alternative conceptions that students have about concepts related to the chemical solutions are similar to the ideas of other students presented in the literature and that the development of the TUPS, allied to the contextualization strategy with the theme water, not only motivated the students for the teaching of chemical content, as yet provided the learning of chemical concepts not in isolation, but making a connection between their ideas and experiences with scientific knowledge. To this, beyond of dialogued lectures, were also used strategies as experimental activities, problem solving, group discussions and construction of concept maps. The final evaluation of the unit was conducted by a questionnaire based on the Likert scale, answered individually by students, who approved the unit as conducive to teaching and learning of chemistry process

Influência do tipo de abrigo e da frequência de oferta alimentar no comportamento do camarão Macrobrachium rosenbergii (De Man 1879)

Macrobrachium rosenbergii is a freshwater prawn which presents agonistic behavior and heterogeneous growth. It is known that captive conditions can intensify agonism causing injuries and decreased survival, generating a condition of poor welfare. Based on this, we aim to investigate the behavior of M. rosenbergii in the juvenile phase according to different types of shelter and frequencies of feed offer, emphasizing their agonistic behavior. For this, juveniles were observed in the laboratory in three steps. At step I we characterized the behavioral profile; prawns were kept in eight aquariums (27 prawns/m2 ), identified and observed four times along both phases of 24 h light cycle. At step II (2 experiments), we evaluated the use of shelters (brick or polyethylene rolls) and their influence on agonism by the animals. For classification of animals in dominance rank, the method used was David's Score. At step III (3 experiments), we evaluated different frequencies of feed offer on the behavior of individuals, in particular agonism. Results showed that juveniles do not present a pattern activity/inactivity between the phases of the light cycle. We identified a dominance hierarchy among individuals taking advantage of access to food by the dominant, which showed greater weight gain although the frequency of intake did not differ between individuals. The type of shelter influenced the behavior of animals. Brick shelter generated a higher frequency of permanence and a reduction in the frequency of agonistic interactions. The distribution of food more frequently throughout the day, decreased the motivation of animals for food, as well as to fight. Prawns fed four times showed lower frequency of feed intake and agonistic interactions. Thus, we conclude the shelters which reduce animal’s detection by coespecifics and offer the food four times along the day reduce agonistic behavior. This result causes na improvement in life quality of the prawns and also in its quality as final product.

Influência da granulometria e taxas de filtração no tratamento de água utilizando dupla filtração

The contamination of water sources of public drinking by waste originated by anthropogenic activities has brought various risks to human health. Among the consequences of such activities can highlight the bloom of microalgae and cyanobacteria, which have the potential to produce toxins dangerous to humans, and the presence of humic substances that are generated by the decomposition of natural organic matter (NOM), such as vegetation. When found in water sources for public supply, present negative aspects conferring high color, odor and taste. The double filtration technology has good efficiency in water with the presence of cyanobacteria and different quality variations. Therefore, this study aimed to evaluate the behavior of the technique of double filtration with pre-oxidation for water purifiers the lagoon of Extremoz-RN, which currently has high concentrations of cyanobacteria. The research is summarized in four phases: the first phase turned to static tests in jarteste equipment in the laboratory and subsequent phases were tested in the Pilot Plant of Double Filtration. For the second and third stage filtration rates were tested filtration rates of 120 and 180 m3 / m2 .day for ascending boulders filters and 160 and 240 m3 / m2 .day in the filters in quick sand descendants. The last phase aimed to evaluate the double filtration with pre-oxidation. The results demonstrated that the system could produce double filtration in all trials of good quality water according to the Decree nº. 2914/11 of the Ministry of Health. The use of preoxidation favored the removal of microcystin and color at the end of the tests, reaching a percentage of color removal around 60%. The analysis of variance in the data, enabled prove that the filtration rates of 180 m3 / m2.d the gravel filter and 240 m3 /m2 .d in rapid filters, were the most significant for the removal of turbidity. The ascending filter of boulder 4 with particle size finer filter layer showed the best performance and the best means of turbidity and apparent color. The rapid filter downward 1 was more efficient in removing turbidity reaching removal about 100%

Uso de água produzida na formulação de fluidos de perfuração

Drilling fluids have fundamental importance in the petroleum activities, since they are responsible for remove the cuttings, maintain pressure and well stability, preventing collapse and inflow of fluid into the rock formation and maintain lubrication and cooling the drill. There are basically three types of drilling fluids: water-based, non-aqueous and aerated based. The water-based drilling fluid is widely used because it is less aggressive to the environment and provide excellent stability and inhibition (when the water based drilling fluid is a inhibition fluid), among other qualities. Produced water is generated simultaneously with oil during production and has high concentrations of metals and contaminants, so it’s necessary to treat for disposal this water. The produced water from the fields of Urucu-AM and Riacho da forquilha-RN have high concentrations of contaminants, metals and salts such as calcium and magnesium, complicating their treatment and disposal. Thus, the objective was to analyze the use of synthetic produced water with similar characteristics of produced water from Urucu-AM and Riacho da Forquilha-RN for formulate a water-based drilling mud, noting the influence of varying the concentration of calcium and magnesium into filtered and rheology tests. We conducted a simple 32 factorial experimental design for statistical modeling of data. The results showed that the varying concentrations of calcium and magnesium did not influence the rheology of the fluid, where in the plastic viscosity, apparent viscosity and the initial and final gels does not varied significantly. For the filtrate tests, calcium concentration in a linear fashion influenced chloride concentration, where when we have a higher concentration of calcium we have a higher the concentration of chloride in the filtrate. For the Urucu’s produced water based fluids, volume of filtrate was observed that the calcium concentration influences quadratically, this means that high calcium concentrations interfere with the power of the inhibitors used in the formulation of the filtered fluid. For Riacho’s produced water based fluid, Calcium’s influences is linear for volume of filtrate. The magnesium concentration was significant only for chloride concentration in a quadratic way just for Urucu’s produced water based fluids. The mud with maximum concentration of magnesium (9,411g/L), but minimal concentration of calcium (0,733g/L) showed good results. Therefore, a maximum water produced by magnesium concentration of 9,411g/L and the maximum calcium concentration of 0,733g/L can be used for formulating water-based drilling fluids, providing appropriate properties for this kind of fluid.

Caracterização de água de lavagem de filtros em estações de tratamento de água de filtração direta

The water supply and treatment is considered as a great benefit considering that, if done efficiently, provides public health. However, considering the WTP (Water Treatment Plant) is an industry, with its inputs and waste generation, they must be constantly evaluated and monitored to verify the best and most appropriate way to process and dispose their waste, minimizing therefore the potential impacts to the environment. By volume, the most significant waste is the rapid filter backwash water. It is very common the disposal of this waste without treatment in water sources, which are used, for the most part, as a water supply source of a downstream population. This study evaluated quantitative and qualitative parameters in filter backwash water in three WTP - Itaitinga, Maranguape and Pacatuba, located in Ceará State, northeast of Brazil. It was found that the Maranguape WTP, in terms of treatment capacity, is the larger. The Itaitinga WTP is the one that consumes more water during filters washing. The Pacatuba WTP exhibited higher concentration of total suspended and settleable solids, COD and aluminum in the filters backwash water. It is noteworthy that the settleable solids and total suspended solids in all three WTP are above the effluent discharge standard recommended by Resolution 154/2002 of SEMACE (State Superintendent of Environment of Ceará). It was concluded that the filter backwash water from the study WTP exceeded the allowed values for legislation to be disposed directly into surface water bodies. It is suggested as an alternative to treat and recycle the filter backwashing water the construction of sludge settling ponds.

Sistema detector de vazamentos em instalações prediais de água fria

Building installations of cold water are key parts in any model of housing, are homes or condos. However, these systems are subject to failure, which can range from a leak in a device until faults in the structure of water reservoirs and distribution system. These faults are responsible for great economic and environmental costs. In order to reduce these losses, this work proposes the development of a system able to detect the presence and identify some types of water leaks that may occur. For implementation and testing, consumption model was used in a simulator capable of reproducing a similar behavior to a real model and its consequent failures. The detection of leaks is done based on an expert like model having two detection modules, one active and one passive, which use an array of sensors and actuators (valves) to do the sensing. For testing and implementation has been developed a software capable of coupling the system simulator and detector. From the results it can be seen that the system proposed in this work, as well as functioning satisfactorily, can be easily implemented in microcontrollers or embedded systems due to its simplicity.

Avaliação da variação sedimentológica em uma área da plataforma continental sob a atuação da indústria petrolífera

Petroleum exploration activity occurs on the offshore Potiguar Basin, from very shallow (2-3 m) until about 50 m water depth, extending from Alto de Touros (RN) to Alto de Fortaleza (CE). Take in account the biological importance and the heterogeneity of sediments on this area, it is necessary the understanding of the sedimentological dynamics, and mainly the changes generated by petroleum exploration to prevent possible damages to environment. Despite the intense activity of oil exploration in this area, research projects like these are still rare. In view to minimize this gap, this study was developed to evaluate sedimentological, mineralogical and geochemical changes in the vicinity of a exploration well, here designated as well A, located on the Middle continental shelf, near the transition to Outer shelf. The well selected for this study was the first one drilled with Riserless Mud Recovery technology (RMR) in Brazil. The main difference from this to the conventional method is the possibility of drilling phase I of the well with return of drilling material to the rig tank, minimizing fluid and gravel discharging around the vicinity, during this phase. Monitoring consisted of three surveys, first of them done before start drilling, the second one done 19 days after the end of drilling and the third one done one year after then. Comparison of the studied variables (calcium carbonate and organic matter content, sediment size, mineralogy and geochemistry) was done with their average, median and coefficient of variation values to understand the changes after drilling activity. Because operating company technical reasons, the well location was changed after the first survey (C1), resulting in a shift of the sampled area on the two last surveys (C2 e C3). Nevertheless, the acquired data presented a good correlation, with no loss to the mean goal of the study. The sedimentological, mineralogical and geochemical analyzes were done at Federal University of Rio Grande do Norte (UFRN). The results indicated a predominantly sandy environment along the three surveys. It was noticed that the first survey (C1), presented different values for all the studied variables than to the second (C2) and third (C3) surveys, which had similar values. Siliciclastic sediments are prevalent at all surveys, and quartz is the main component (more than 80%). Heavy minerals (garnet, turmaline, zircon and lmenite), rock fragments and mud aggregates also was described. Bioclastic sediments are dominated by coralline algae (more than 45%) and mollusks (more than 30%), followed by benthic foraminifera, bryozoans and worm tubes. More rarely was observed ostracoda and spike of calcareous sponge. Because the low changes of the sediments at the studied area and by the using of RMR method in the drilling, it was possible to conclude that drilling activity did not promote significant alteration on the local sediment cover. Changes in the studied variables before and after drilling activity could be influenced by the changing in the sampling area after survey 1 (C1).

Remoção de nitratos em água utilizando diferentes materiais e processos

The need to preserve the environment has led to the search for new materials for efficient disposal of chemical compounds that alter the stability of our natural resources. Among these resources, stands in first place the water, as a precious commodity and scarce, leading to the proper use and reuse. As a result, the World Health Organization has established maximum permissible values in drinking water, such as: 50 mg/L, 0, 1 mg/L and 0, 5 mg/L to at-3, at-2, NH 4, respectively. For these reasons, assesses the implementation of new materials and water treatment processes aiming at the removal of these compounds, such as alumina, in the form of powder or as a support for a catalytic system using inorganic membranes capable of supporting more severe conditions of temperature and pressure by opening new possibilities for applications of membrane reactors; and also for electrochemical treatments with doped diamond bobo electrodes (BDD) as anode and copper as cathode. For such purpose, was conducted the study of adsorption of nitrate in different times to assess the time required to achieve equilibrium by employing three commercial alumina called: acidic, basic and neutral alumina, with subsequent treatment only in the acidic alumina impregnating metals (PdCu/Al2O3) for the catalytic reaction. The materials were previously characterized by XRD, SEM techniques and ABET. Aluminas presented a considerable adsortive capacity of nitrate in the first thirty minutes, equivalent to 50% of removal reaching equilibrium in that time. After treatment, using alumina as catalyst for the reaction in batch reactor (Pd-Cu/Al2O3), the results were more favourable, totalling 64% reduction of ion NO3-at the end of three hours. On the other hand, the results for the catalytic reaction using the catalytic support Pd-Cu/TiO2 in membrane reactor proved to be low. -if, in this way, improve the conditions of catalytic system to optimize the process. Already, for the electrochemical tests using DDB1 electrodes as anode, and Cu, as cathode, there was a fairly significant nitrate reduction, approximately 80% of ion removal during three hours and cost viable applications.

Influência de eventos hidrológicos extremos na qualidade da água de reservatórios na região tropical semiárida

Reservoirs are artificial ecosystems, intermediate between rivers and lakes, with diferent morphological and hydrological characteristics that can provide many important benefits to society. However, the use of this water for human consumption, watering livestock, leisure, irrigated agricultural production and pisciculture development, directly influence the increase loading of nutrients to aquatic environments and contribute to acceleration of eutrophication. Furthermore, global climate models are predicting a higher occurrence of extreme events such as floods and severe droughts, which will create hydrological stresses in lakes. In the semiarid northeast we can see the occurrence of these events, the drought of the years 2012, 2013 and 2014 was the worst drought in 60 years, according to the National Water Agency (ANA). Thus, this study aimed to evaluate the quality of the semiarid tropical water sources, identifying temporal patterns in periods with extreme hydrological events (floods and severe droughts). The study results showed that Gargalheiras and Cruzeta reservoirs presented significative changes in the limnological variables between rain and severe drought periods, with better appearance and in the most of the water quality variables in the rainy season and higher nutrientes concentrations and high electrical conductivity values in severe season, indicating decay of its quality. However, we found diferent behaviors between the reservoirs in severe drought. While Gargalheiras showed a typical behavior of the region, with high concentrations of algal biomass, indicating the worsening eutrophication, Cruzeta demonstrated a colapse in the total phytoplankton biomass, evidenced by the decrease in chla concentrations. This fact occurred because the low depth and proximity with the sediment facilited the inorganic solids resuspension and, consequently, resulted in turbid water column and light by limitation. In addition, the different behaviors between the reservoirs indicate that the responses of these environments problems such as extreme events must take into account factors such the region climate, size, depth of the reservoir and the basin characteristics.

Estudo da variação da periodicidade e do acoplamento entre superfícies seletivas de frequência com elementos fractais e helicoidais em estruturas de multicamadas

This work aims to investigate the behavior of fractal and helical elements structures in planar microstrip. In particular, the frequency selective surfaces (FSSs) had changed its conventional elements to fractal and helical formats. The dielectric substrate used was fiberglass (FR-4) and has a thickness of 1.5 mm, a relative permittivity 4.4 and tangent loss equal to 0.02. For FSSs, was adopting the Dürer’s fractal geometry and helical geometry. To make the measurements, we used two antennas horns in direct line of sight, connected by coaxial cable to the vector network analyzer. Some prototypes were select for built and measured. From preliminary results, it was aimed to find practical applications for structures from the cascading between them. For FSSs with Dürer’s fractal elements was observed behavior provided by the multiband fractal geometry, while the bandwidth has become narrow as the level of iteration fractal increased, making it a more selective frequency with a higher quality factor. A parametric analysis allowed the analysis of the variation of the air layer between them. The cascading between fractal elements structure were considered, presented a tri-band behavior for certain values of the layer of air between them, and find applications in the licensed 2.5GHz band (2.3-2.7) and 3.5GHz band (3.3-3.8). For FSSs with helical elements, six structures were considered, namely H0, H1, H2, H3, H4 and H5. The electromagnetic behavior of them was analyzed separately and cascaded. From preliminary results obtained from the separate analysis of structures, including the cascade, the higher the bandwidth, in that the thickness of the air layer increases. In order to find practical applications for helical structures cascaded, the helical elements structure has been cascaded find applications in the X-band (8.0-12.0) and unlicensed band (5.25-5.85). For numerical and experimental characterization of the structures discussed was used, respectively, the commercial software Ansoft Designer and a vector network analyzer, Agilent N5230A model.

Morfometria, variação anual no peso e demografia do Tico-tico-rei-cinza (Lanio pileatus: thraupidae) em dois ambientes de caatinga no nordeste do Brasil

The caatinga is considered the only exclusively Brazilian biome, with a total area of 735.000km². It is estimated that about 59% of this area has already been removed and only 2% are protected in conservations units. The region is characteristic by strong seasonality and heterogeneity in their environments. This paper sets generate information on morphological and population patterns Lanio pilatus in two areas of caatinga of Estação Ecológica do Seridó (ESEC – Seridó), Serra Negra do Norte - RN. Data collection was performed in six phases between July 2012 and December 2014, covering the end of the dry and rainy seasons in the region. The captures were performed with nets and individuals captured were marked with metal rings and measured (weight, wing length, tail, tarsus, culmen and tip of the bill to nostril). Through these measures, we observed that only males of open area range in weight during the dry and rainy season, youngs were significantly lower for all parameters measured, and males were larger than females in three characteristics (weight, wing length and tail) in open area and only one (wing length) in the closed area. The population parameters were generated from the mark-capture-recapture technique by program MARK, using the techniques of robust design and CJS. The survival probability of detection and population estimates varied with time. Only individuals of open area fluctuated in their estimates during the study. Overall, the environment was a great mediator of results which increases the need for more studies on the life history of the species in the region.

Lâminas de água salina e doses de adubação orgânica na produção de palma Miúda adensada no semiárido

Cactus pear is an important forage for livestock in semi-arid region of Brazil, due to its adaptation to climate conditions in this region, high productivity and nutritional value. The yield of this cactus has positively responded to techniques such as planting density, fertilization and cutting managements, however, in Rio Grande do Norte State, only certain areas have favorable climate conditions to the development of this crop. Drip irrigation, with a small amount of water, has proven to be an alternative to the viability of cactus pear cultivation in these areas. The research aimed to evaluate the effects of different levels of saline water and manure organic fertilization on the morphological characteristics and production of fresh and dry matter of the prickly-pear cactus cv. Miúda (Nopalea cochenillifera Salm Dick) in a dense planting system. The experiment was conducted at the Experimental Station of Terras Secas (EMPARN), Pedro Avelino, latitude 5°31'21" South and longitude 36°23'14" West. The soil was classified as Typical Cambisol Haplicum Carbonate and the water used in irrigation, C4S1T3 (5,25 dS.m-1), with planting spacing of 2.0 x 0.25 m (20,000 plants ha-1). A completely randomized design in a split plot was used, where water levels (0, 7.5, 15.0 and 30.0 mm month-1) with 10 days intervals, were the main plots and organic fertilization (0 , 25 and 50 Mg ha-1 yr-1) the subplots, with four replicates. The measured morphological characteristics were number of cladodes, height and volume of the plant; length, width, perimeter, thickness, area and cladodes area index, fresh and dry matter production, dry matter content, water use efficiency (WUE) and damage promoted by cochineal pest (Diaspis echinocacti) and soft rot (Erwinia carotovora). There was no influence (P>0.05) of organic fertilization on most variables, particularly in relation to the production of fresh and dry matter. The water levels had a significant influence (P<0.05) on most variables, promoting higher height and volume of the plants, larger and thicker cladodes, and increase on fresh and dry matter production (13.55 Mg DM ha-1 yr-1). The absence of irrigation caused a significant expansion in plant damage caused by the cochineal pest and when irrigated with different water levels there was an increase in damage and stand loss, caused by soft rot, been more intense at the higher water level.

Sistema mecatrônico de tempo real para monitoramento da qualidade da água embarcado em veleiro robótico autônomo

We propose a mechatronic system for monitoring water quality in rivers, lakes, dams and sea, able to perform the acquisition, processing and presentation of data via the web in real time, in order to facilitate analysis quickly and needs by interested communities. The hardware architecture and software monitoring system has been developed so that it can be generic, that is, supporting different applications. Nevertheless, as a validation of the proposed system, we built a prototype that operates embarked on an autonomous robotic sailboat, a responsible platform for collecting the data in multiple predefined points from a ground station with a planning system navigation. This final application combines the advantages of autonomy of a robotic sailboat with the need for fast and accurate monitoring of water quality, in addition to the use of an autonomous robotic sailboat unmanned facilitate the development of other research in this area.

Estudo experimental sobre o comportamento do escoamento bifásico água - ar para a medição de vazão em placa de orifício

The measurement of flow through the prediction of differential pressure is widely used in industrial day-to-day, this happens mainly due to the fact that it is used for various types of fluids, such as gas flow and liquid with viscosity distinct even flow of fluids with particles in suspension. The suitability of this equipment for measuring mass flow in two-phase flow is of paramount importance for technological development and reliability of results. When it comes to two-phase flow the relationship between the fluids and their interactions are of paramount importance in predicting the flow. In this paper, we propose the use of concentric orifice plate used in small diameter pipes of 25.4 mm order where a two-phase flow flows between water-air. The measurement of single-phase flow was made with the use of data in NBR 5167-1 which was used to Stolz equation for measuring discharge coefficient. In the two-phase flow was used two correlations widely used in the prognosis of mass flow, the pattern of Zhang (1992) and the model of Chisholm (1967), to the homogeneous flow model. It was observed that the behavior found in Zhang model are consistent more realistic way the mass flow of two-phase flow, since the model Chisholm extrapolate the parameters for the downstream pressure P2, the orifice plate, and the rated discharge coefficient. The use of the change in pressure drop P1-P2 and discharge coefficient, led to a better convergence of the values obtained for the two-phase air-water stream.

Padrões de diversidade α (alfa) e β (beta) zooplanctônica em lagos tropicais: a importância da estrutura do habitat e da identidade das espécies

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)