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.

Síntese e caracterização de PSFC (Pr0,5Sr0,5Fe1-xCuxO3-δ, sendo x=0,2 e x=0,4) para aplicação como catodo de células a combustível de óxido sólido

The PSFC (Pr0.5Sr0.5Fe1-xCuxO3-δ) is a new mixed oxide perovskite and has been studied and evaluated the cathode materials for intermediate temperature solid oxide fuel cells (IT-SOFCs), mainly due to its good compatibility with the electrolyte (CGO) and its high ionic conductivity and electronic in intermediate temperature. In this work, PSFC powders with two different compositions (Pr0,5Sr0,5Fe0,8Cu0,2O3- PSFC5582 and Pr0,5Sr0,5Fe0,6Cu0,4O3-PSFC5564) were synthesized by the citrate method using a new route. The powders obtained were characterized by thermal analysis (Differential Scanning Calorimetry and Thermogravimetry), and the material calcined at 800, 900 and 1000 °C for 5h were analyzed by X-ray diffractometry (XRD), with the Rietveld refinement of the diffraction data and dilatometry. PSFC5582 composite films were obtained by screen printing of powder calcined at 1000 °C. The films were deposited on substrate ceria doped with gadolinia (CGO) and then sintered at 1050 °C for 2h. The electrochemical performance of the electrodes was evaluated by impedance spectroscopy and the interface electrode/electrolyte was observed by scanning electron microscopy (SEM). The specific resistance area (ASR) was 0.44 Ω.cm² at 800 °C, slightly lower than those reported in the literature for cathodes containing cobalt. The thermal expansion coefficients of both the PSFC compositions were obtained and varied between 13 and 15 x 10-6 °C-1 , in a temperature range of 200 to 650 °C, demonstrating the good thermal compatibility of cathodes with Ce0,9Gd0,1O1,95 electrolytes (CET = 12 x 10-6 °C).

Compósitos NiO-CGO obtidos pelo método de síntese em uma etapa

Composite NiO-C0.9Gd0.1O1.95 (NiO-GDC), one of the materials most used for the manufacture of anodes of Cells Solid Oxide Fuel (SOFC) currently, were obtained by a chemical route which consists in mixing the precursor solution of NiO and CGO phases obtained previously by the Pechini method. The nanopowders as-obtained were characterized by thermal analysis techniques (thermogravimetry and Differential Scanning Calorimetry) and calcined materials were evaluated by X-ray diffraction (XRD). Samples sintered between 1400 and 1500 ° C for 4 h were characterized by Archimedes method. The effects of the composition on the microstructure and electrical properties (conductivity and activation energy) of the composites sintered at 1500 ° C were investigated by electron microscopy and impedance spectroscopy (between 300 and 650 ° C in air). The refinement of the XRD data indicated that the powders are ultrafine and the crystallite size of the CGO phase decreases with increasing content of NiO. Similarly, the crystallite of the NiO phase tends to decrease with increasing concentration of CGO, especially above 50 wt % CGO. Analysis by Archimedes shows a variation in relative density due to the NiO content. Densities above 95% were obtained in samples containing from 50 wt % NiO and sintered between 1450 and 1500 °C. The results of microscopy and impedance spectroscopy indicate that from 30-40 wt.% NiO there is an increase in the number of contacts NiO - NiO, activating the electronic conduction mechanism which governs the process of conducting at low temperatures (300 - 500 °C). On the other hand, with increasing the measuring temperature the mobility of oxygen vacancies becomes larger than that of the electronic holes of NiO, as a result, the high temperature conductivity (500-650 ° C) in composites containing up to 30-40 wt.% of NiO is lower than that of CGO. Variations in activation energy confirm change of conduction mechanism with the increase of the NiO content. The composite containing 50 wt. % of each phase shows conductivity of 19 mS/cm at 650 °C (slightly higher than 13 mS/cm found for CGO) and activation energy of 0.49 eV.

Desenvolvimento de material BaCexPr1-xO3 (0 ≤ X ≤ 1) com estrutura perovskita para oxidação catalítica do CO a CO2 em reator de leito fixo

Barium Cerate (BaCeO3) is perovskite type structure of ABO3, wherein A and B are metal cations. These materials, or doped, have been studied by having characteristics that make them promising for the application in fuel cells solid oxide, hydrogen and oxygen permeation, as catalysts, etc .. However, as the ceramic materials mixed conductivity have been produced by different synthesis methods, some conditions directly influence the final properties, one of the most important doping Site B, which may have direct influence on the crystallite size, which in turn directly influences their catalytic activity. In this study, perovskite-type (BaCexO3) had cerium gradually replaced by praseodymium to obtain ternary type materials BaCexPr1-xO3 and BaPrO3 binaries. These materials were synthesized by EDTA/Citrate complexing method and the material characterized via XRD, SEM and BET for the identification of their structure, morphology and surface area. Moreover were performed on all materials, catalytic test in a fixed bed reactor for the identification of that person responsible for complete conversion of CO to CO2 at low operating temperature, which step can be used as the subsequent production of synthesis gas (CO + H2) from methane oxidation. In the present work the crystalline phase having the orthorhombic structure was obtained for all compositions, with a morphology consisting of agglomerated particles being more pronounced with increasing praseodymium in the crystal structure. The average crystal size was between 100 nm and 142,2 nm. The surface areas were 2,62 m²g-1 for the BaCeO3 composition, 3,03 m²g-1 to BaCe0,5Pr0,5O3 composition and 2,37 m²g-1 to BaPrO3 composition. Regarding the catalytic tests, we can conclude that the optimal flow reactor operation was 50 ml / min and the composition regarding the maximum rate of conversion to the lowest temperature was BaCeO3 to 400° C. Meanwhile, there was found that the partially replaced by praseodymium, cerium, there was a decrease in the catalytic activity of the material.

O impacto da remoção de peixes sobre a dinâmica e estrutura dos grupos funcionais fitoplanctônicos em um lago raso tropical durante uma seca severa

The artifi cial eutrophication is one of the biggest t h reat for the quality of aquatic ecosystems in the whole world. The expectations for the future climatic scenarios in arid and semi - arid regions are intense and frequent droughts enhancing the risk of eutrophicati on and cyanobacterial blooms. Restoration techniques of eutrophic lakes were proposed to reduce nutrient loading and improve the water quality. A successful technique used in temperate regions is the biomanipulation by benthivorous fish removal . Our hypoth esis is that the benthivorous fish removal reduces phytoplankton total biomass and change the composition of phytoplankton functional groups, improving water quality. The aim of the study was evaluate the impact of biomanipulation on phytoplankton function al groups and in the water quality. We applied the technique of biomanipulation in the artificial lake ESEC, in a semi - arid region of Brazil and analyzed the physical and chemical variables and the dynamic of phytoplankton functional groups monthly during November 2012 to August 2013. With the removal of benthivorous fish we observed a significant increase of the euphotic depth, phytoplankton richness and the recruitment of green algae (groups F and J ), indicators of good water quality. However, we did not observe significant differences on total phosphorous concentration and on phytoplankton biomass and diversity. The drought effect in the region during the study was evident , promoting a drastic reduction on water level which influenced the availability of resource and affected phytoplankton community before the biomanipulation. To evaluate the effect of severe drought on the dynamic of phytoplankton functional groups and test if the drought periods are favorable to dominance of cyanobacterial groups, we stu died two artificial neighbors lakes (ESEC and Pocinhos) in a semi - arid tropical region during May 2012 to February 2013. We observed a temporal differentiation of biotic and abiotic variables caused by drought. Both lakes presented reduction of 2 meters of water level and increase on conductivity, turbidity, nutrients concentration and a reduction on water transparency, during the severe drought. The deeper lake (Pocinhos) increased phytoplankton total biomass and presented cyanobacterial functional group d ominance (group S N ) and the shallower lake (ESEC) reduced phytoplankton total biomass and presented dominance of mixotrophic and flagellate functional groups (groups W 1 e W 2 ). Summarizing, the knowledge of the effects of benthivorous fish removal in semi - a rid tropical lakes still unknown and this study had limitations caused by the impact of drought. Thus, it is necessary a long term monitoring to investigate the real effects of biomanipulation on the functioning of the studied ecosystems. Otherwise, period s of drought could have opposite effects (increase or reduction) on total biomass and composition of phytoplankton functional groups. Drought not always leads to dominance of cyanobacterial groups.

Estudo da eficiência eletroquímica para tratamento de chorume gerado em aterro sanitário brasileiro

This work was performing effluent degradation studies by electrochemical treatment. The electrochemical oxidation (EO) hydroquinone (H2Q) was carried out in acid medium, using PbO2 electrode by galvanostatic electrolysis, applying current densities of 10 and 30 mA/cm2 . The concentration of H2Q was monitored by differential pulse voltammetry (DPV). The experimental results showed that the galvanostatic electrolysis process performance significantly depends on the applied current density, achieving removal efficiencies of 100% and 80 % and 10 applying 30 mA/cm2 , respectively. Furthermore, the electroanalytical technique was effective in H2Q be used as a detection method. In order to test the efficiency of PbO2 electrode, the electrochemical treatment was conducted in an actual effluent, leachate from a landfill. The liquid waste leachate (600ml effluent) was treated in a batch electrochemical cell, with or without addition of NaCl by applying 7 mA/cm2 . The efficiency of EO was assessed against the removal of thermo-tolerant coliforms, total organic carbon (TOC), total phosphorus and metals (copper, cobalt, chromium, iron and nickel). These results showed that efficient removal of coliforms was obtained (100%), and was further decrease the concentration of heavy metals by the cathode processes. However, results were not satisfactory TOC, achieving low total removal of dissolved organic load. Because it is considered an effluent complex were developed other tests with this effluent to monitor a larger number of decontamination parameters (Turbidity, Total Solids, Color, Conductivity, Total Organic Carbon (TOC) and metals (barium, chromium, lithium, manganese and Zinc), comparing the efficiency of this type of electrochemical treatment (EO or electrocoagulation) using a flow cell. In this assay was compared to electro streaming. In the case of the OE, Ti/IrO2-TaO5 was used as the anode, however, the electrocoagulation process, aluminum electrodes were used; applying current densities of 10, 20 and 30 mA/cm2 in the presence and absence of NaCl as an electrolyte. The results showed that EO using Ti/IrO2–TaO5 was anode as efficient when Cl- was present in the effluent. In contrast, the electrocoagulation flow reduces the dissolved organic matter in the effluent, under certain experimental conditions.

Estudo sobre a relação entre a atividade geomagnética e cintilações de sinais de GPS em Natal-RN (Brasil)

To identify the relationship between GPS scintillation in Natal-RN (Brazil) and geomagnetic disturbances of any intensities and variations, this work made analysis of the ionospheric behavior and magnetic indexes (Dst , AE and Bz of the interplanetary magnetic field) concerning to different periods of the solar cycle between 2000 and 2014. Part of the data of this research originated at the UFRN observatory, from a GEC Plessey board connected to an ANP -C 114 antenna, modified by Cornell University’s Space group Plasma Physics in order to operate the ScintMon, a GPS monitoring program. This study, therefore, found several cases of inhibited scintillations after the main phase of magnetic storms, a fact that, along with others, corroborated with categorization of Aarons (1991) and models of disturbed dynamo (according to Bonelli, 2008) and over-shielding penetration, defended by Kelley et al. (1979) and Abdu (2011) [4]. In addition to these findings, different morphologies were noted in such disruptions in the GPS signal in accordance with previous magnetic activities. It also found a moderate relationship (R2 = 0.52) between the Dst rate (concerning to specific time) and the average of S4 through a polynomial function. This finding therefore, corroborating Ilma et al. (2012) [17], is an important evidence that the scintillation GPS are not directly controlled by magnetic induction of storms. Completing this work, this relation did show itself as a way of partial predicting of scintillations.

Desenvolvimento e caracterização de um eco-compósito de poliuretano de mamona e fibra de lã canina

The Sustainability has been evidence in the world today; organizations have sought to be more and more into this philosophy in their processes, whether products or attendance. In the present work were manufactured eco-composites with animal fiber (dog wool) that is currently discarded into the environment without any use. Project phases consisted on the initial treatment of fibers with alkaline solution (NaOH) at 0.05 mols for removal of impurities, developing methods to convert these fibers (reinforcement) blended with castor oil polyurethane (matrix) in eco-composite with different proportions (5%, 10%, 15% and 20%). Fiber properties were evaluated by analysis of SEM, XRD and FTIR. The composites were produced by compression molding with dimensions 30x30x1cm. For characterization of the composites the following tests were performed: mechanical (tensile, compression, shore hardness A) according the standards and testing water absorption, moisture regain and biodegradation. The analysis of thermal properties on fibers and composites were by TG, DSC, thermal conductivity, resistivity, heat capacity and thermal resistance. Analyzing the results of these tests, it was observed that the composite reinforced with 20% showed a better thermal performance between others composites and dimensional stability when compared to commercial thermal insulation. Also is possible to observe a balance in moisture absorption of the composite being shown with its higher absorption rate in this same sample (20%). The micrographs show the fiber interaction regions with polyurethane to fill the empty spaces. In hardness and compression testing can identify that with increasing percentage of the fiber material acquires a greater stiffness by making a higher voltage is used for forming necessary. So by the tests performed in eco-composites, the highest percentage of fiber used as reinforcement in their composition obtained a better performance compared to the remaining eco-composites, reaching values very close to the PU.

Ocorrência de leite instável na região semiárida do Rio Grande do Norte e sua correlação com a qualidade do leite

The unstable non acid milk (UNAM) is characterized by coagulation in the alcohol test and wanted acidity (14-18°D). Among Brazilian regions, the South and Southeast have the highest occurrence of LINA, which has been causing problems for both producers and for industries, due to the disposal or undervaluation of milk. In the Northeast there are few studies that indicate their occurrence and quality. The objective of this study was to identify the occurrence of unstable non-acid milk in the west and central mesoregions of Rio Grande do Norte, determine their physicochemical characteristics, test alcoholic graduations and evaluate their correlation with the quality of milk. 176 raw milk samples were analyzed in the period from September to December /2014 from 23 APASA’s cooling tanks, located in 7 cities of west and central mesoregions RN. The samples were collected in duplicate, one sample used for alcohol testing at 68, 72 and 76%, measurement of pH, acidity, electrical conductivity and boiling proof, made in LABOLEITE / UFRN; and the other sample containing Bronopol® preservative, was sent to the APCBRH (Cattle Breeders Association Paranaense Holstein) laboratory in Curitiba-PR, which were analyzed fat, protein, total solids, lactose, casein, urea nitrogen and somatic cell count. The test alcohol samples disapproved 31.82%, of which 30% proved to be non-acid, and 30% had high acidity. The samples were divided into three classes: Stable Milk, UNAM and acid milk. 3% Tukey test was used for comparison of stable milk components and UNAM and there was no significant difference between them. Both classes obtained averages within the standard required by IN 62. The average value of electric conductivity was 4.84 mS/cm for stable milk, 4.55 mS/cm for unstable and acid milk and 4.53 mS/cm for non-acid unstable milk. The electrical conductivity was positively correlated with alcohol stability of milk and negative correlation with acidity and pH. Could not observe direct relationship between the electrical conductivity and the somatic cell count.The boiling test was negative for all samples UNAM. It can be concluded that the incidence of UNAM in the studied region is low, although the predisposing factors such as heat stress, drought and nutritional deficiency. In conclusion, the UNAM has quality similar to stable milk, conform the norms required by Agriculture Ministry, and with adequate thermal stability, which proves that there is no reason to reject this milk by industry.

Aplicação e otimização de métodos eletroquímicos combinados para remoção e determinação de cromo hexavalente em efluentes simulados

Hexavalent chromium is a heavy metal present in various industrial effluents, and depending on its concentration may cause irreparable damage to the environment and to humans. Facing this surrounding context, this study aimed on the application of electrochemical methods to determine and remove the hexavalent chromium (Cr6+) in simulated wastewater. To determine was applied to cathodic stripping voltammetry (CSV) using ultra trace graphite electrodes ultra trace (work), Ag/AgCl (reference) and platinum (counter electrode), the samples were complexed with 1,5- diphenylcarbazide and then subjected to analysis. The removal of Cr6+ was applied electrocoagulation process (EC) using Fe and Al electrodes. The variables that constituted the factorial design 24, applied to optimizing the EC process, were: current density (5 and 10 mA.cm-2), temperature (25 and 60 ºC), concentration (50 and 100 ppm) and agitation rate (400 and 600 RPM). Through the preliminary test it was possible the adequacy of applying the CSV for determining of Cr6+, removed during the EC process. The Fe and Al electrodes as anodes sacrifice showed satisfactory results in the EC process, however Fe favored complete removal in 30 min, whereas with Al occurred at 240 min. In the application of factorial design 24 and analysis of Response Surface Methodology was possible to optimize the EC process for removal of Cr6+ in H2SO4 solution (0.5 mol.L-1), in which the temperature, with positive effect, was the variable that presented higher statistical significance compared with other variables and interactions, while in optimizing the EC process for removal of Cr6+ in NaCl solution (0.1 mol.L-1) the current density, with positive effect, and concentration, with a negative effect were the variables that had greater statistical significance with greater statistical significance compared with other variables and interactions. The utilization of electrolytes supports NaCl and Na2SO4 showed no significant differences, however NaCl resulted in rapid improvement in Cr6+ removal kinetics and increasing the NaCl concentration provided an increase in conductivity of the solution, resulting in lower energy consumption. The wear of the electrodes evaluated in all the process of EC showed that the Al in H2SO4 solution (0.5 mol.L-1), undergoes during the process of anodization CE, then the experimental mass loss is less than the theoretical mass loss, however, the Fe in the same medium showed a loss of mass greater experimental estimated theoretically. This fact is due to a spontaneous reaction of Fe with H2SO4, and when the reaction medium was the NaCl and Na2SO4 loss experimental mass approached the theoretical mass loss. Furthermore, it was observed the energy consumption of all processes involved in this study had a low operating cost, thus enabling the application of the EC process for treating industrial effluents. The results were satisfactory, it was achieved complete removal of Cr6+ in all processes used in this study.

Influência da pressão e da vazão de concentrado sobre o desempenho de ultrafiltração no pós-tratamento de esgotos

Despite the numerous advantages resulting from the use of membrane filters technology, intrinsic limitations fouling process become relevant to its applicability. The control of operating conditions is an important tool to mitigate fouling and achieve good levels of efficiency. In this sense, the objective of this study was to investigate the effect of transmembrane pressure and concentrate flow in the performance of ultrafiltration, applied to the post-treatment of domestic sewage. The process was evaluated and optimized by varying the pressure (0.5 and 1.5 bar) and the concentrate flow (300 and 600 L/h), using a 22 factorial design, in order to investigate the effects on the permeate flow and quality of effluents generated at each operating condition. We evaluated the following quality indicators for permeate: pH, electrical conductivity, total suspended solids, turbidity, calcium and Chemical Oxygen Demand (COD). In all tests, we observed marked reduction in the permeate flux at the early stages, followed by a slow decline that lasted until it reaches a relatively constant level, around 120 minutes of filtration. The increased pressure resulted in a higher initial permeate flux, but the decrease of the flow with time is greater for tests at higher pressure, indicating a more pronounced fouling process. On the other hand, increasing the concentrate flow resulted in a slower decline in permeate flux with the filtration time. Regarding the quality of permeate, the transmembrane pressure of 0,5 bar was the one that allowed better results, and was statistically confirmed through the two-way ANOVA test with repeated measures, significant effect of pressure on the turbidity of the permeate. The concentrate flow, in turn, showed no significant influence on any of the quality parameters. Thus, we conclude that, from an economic and environmental point of view, it is more interesting to operate ultrafiltration membrane system with a lower concentrate flow associated with a low transmembrane pressure, since under these conditions will produce less waste, and the permeate will present lower concentrations of the analyzed constituent, especially lower turbidity.

Testes para a avaliação da qualidade fisiológica de sementes de Moringa oleifera Lam

The evaluation of seed vigor is an important factor for detection of lots of high quality seeds, so that development of procedures to evaluate the physiological potential has been an important tool in quality control programs seeds. In this sense the study aimed to adapt the methodologies of accelerated aging, electrical conductivity and potassium leaching to evaluate Moringa oleifera seed vigor LAM.. Therefore, four lots of moringa seeds were subjected to the germination tests, seedling emergence, speed of emergence index, emergence first count, length and dry mass of seedlings and cold test for their physiological characterization, in addition to accelerated aging, electrical conductivity and potassium leaching. The experimental design was completely randomized with four replications of 50 seeds and the means compared by Tukey test at 5% probability. For accelerated aging the periods were studied aging 12, 24 and 72 hours at 40, 42 and 45°C. For the electrical conductivity test was used to a temperature of 25°C for periods of 4, 8, 12, 16 and 24 hours of immersion in 75 to 125 mL of distilled water, using 25 to 50 seeds, and for potassium leaching test samples were used 25 to 50 seeds, placed in plastic cups containing 70 and 100 mL of distilled water at 25°C for periods of 1, 2, 3, 4, 5 and 6 hours. From the results obtained, it can be inferred that the methods best fit for the accelerated aging test Moringa seeds were a temperature of 40°C for 12 to 72 hours, 42°C 72 hours 45°C 24 hours . In the electrical conductivity test Moringa seeds, the combination of 50 seeds in 75 mL distilled water for a period of immersion of 4 hours and 50 seeds in 125 mL of 4 hours were efficient for the differentiation of lots of Moringa seeds as to vigor and for potassium leaching test moringa seeds, the combination of 50 seeds in 100mL of distilled water allowed the separation of lots of four levels of vigor, at 2 hours of immersion, showing promise in evaluate the quality of moringa seeds.

Testes para a avaliação da qualidade fisiológica de sementes de Moringa oleifera Lam

The evaluation of seed vigor is an important factor for detection of lots of high quality seeds, so that development of procedures to evaluate the physiological potential has been an important tool in quality control programs seeds. In this sense the study aimed to adapt the methodologies of accelerated aging, electrical conductivity and potassium leaching to evaluate Moringa oleifera seed vigor LAM.. Therefore, four lots of moringa seeds were subjected to the germination tests, seedling emergence, speed of emergence index, emergence first count, length and dry mass of seedlings and cold test for their physiological characterization, in addition to accelerated aging, electrical conductivity and potassium leaching. The experimental design was completely randomized with four replications of 50 seeds and the means compared by Tukey test at 5% probability. For accelerated aging the periods were studied aging 12, 24 and 72 hours at 40, 42 and 45°C. For the electrical conductivity test was used to a temperature of 25°C for periods of 4, 8, 12, 16 and 24 hours of immersion in 75 to 125 mL of distilled water, using 25 to 50 seeds, and for potassium leaching test samples were used 25 to 50 seeds, placed in plastic cups containing 70 and 100 mL of distilled water at 25°C for periods of 1, 2, 3, 4, 5 and 6 hours. From the results obtained, it can be inferred that the methods best fit for the accelerated aging test Moringa seeds were a temperature of 40°C for 12 to 72 hours, 42°C 72 hours 45°C 24 hours . In the electrical conductivity test Moringa seeds, the combination of 50 seeds in 75 mL distilled water for a period of immersion of 4 hours and 50 seeds in 125 mL of 4 hours were efficient for the differentiation of lots of Moringa seeds as to vigor and for potassium leaching test moringa seeds, the combination of 50 seeds in 100mL of distilled water allowed the separation of lots of four levels of vigor, at 2 hours of immersion, showing promise in evaluate the quality of moringa seeds.

Obtenção e caracterização de um eco-compósito à base de látex e bainha da palha do coqueiro para isolamento térmico e acústico

With the emergence of new technologies, has grown the need to use new materials, and this has intensified research on the collection and use of materials from renewable sources, is to reduce production costs and / or environmental impact. In this context, it was found that the sheath coconut straw, can be utilized as raw material for the production of a eco-composite that can be used as a thermal and acoustic insulator. After selected from the coconut sheaths were subjected to treatment with aqueous 2 % sodium hydroxide (NaOH). The composite study was produced with the sheath and coconut natural latex, with coconut sheath percentage in the proportions 15%, 25% and 35% of the total compound volume. Physical, thermal and acoustic properties of the composites were analyzed in order to obtain data on the use of viability as thermoacoustic insulation. The CP15 composites, CP25 and CP35 showed thermal conductivity 0.188 W/m.K, 0.155 W/m.K and 0.150 W/m.K, respectively. It can be applied as thermal insulation in hot systems to 200 ° C. The CP35 composite was more efficient as a thermal and acoustic insulation, providing 20% noise reduction, 31% and 34% for frequencies of 1 kHz, 2 kHz and 4 kHz, respectively. The analyzes were based on ABNT, ASTM, UL. Based on these results, it can be concluded that the eco-composite produced the hem of coconut can be used as thermal and acoustic insulation. Thus, it gives a more noble end to this material, which most often is burned or disposed of improperly in the environment.

Obtenção e caracterização de um eco-compósito à base de látex e bainha da palha do coqueiro para isolamento térmico e acústico

With the emergence of new technologies, has grown the need to use new materials, and this has intensified research on the collection and use of materials from renewable sources, is to reduce production costs and / or environmental impact. In this context, it was found that the sheath coconut straw, can be utilized as raw material for the production of a eco-composite that can be used as a thermal and acoustic insulator. After selected from the coconut sheaths were subjected to treatment with aqueous 2 % sodium hydroxide (NaOH). The composite study was produced with the sheath and coconut natural latex, with coconut sheath percentage in the proportions 15%, 25% and 35% of the total compound volume. Physical, thermal and acoustic properties of the composites were analyzed in order to obtain data on the use of viability as thermoacoustic insulation. The CP15 composites, CP25 and CP35 showed thermal conductivity 0.188 W/m.K, 0.155 W/m.K and 0.150 W/m.K, respectively. It can be applied as thermal insulation in hot systems to 200 ° C. The CP35 composite was more efficient as a thermal and acoustic insulation, providing 20% noise reduction, 31% and 34% for frequencies of 1 kHz, 2 kHz and 4 kHz, respectively. The analyzes were based on ABNT, ASTM, UL. Based on these results, it can be concluded that the eco-composite produced the hem of coconut can be used as thermal and acoustic insulation. Thus, it gives a more noble end to this material, which most often is burned or disposed of improperly in the environment.