98 resultados para Organic and Polymer Systems


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Injection metering systems are an important option for the development of pesticide application equipment, with advantages relating to minimising the need for disposal of unused pesticide, improving the ease of cleaning and optimising the accuracy of chemical application. For all injection systems, characteristics such as the steady-state accuracy of delivered dose, dose stability and the time response for dose step changes are related to the ability of the system to operate with different chemical formulations. A system designed to inject liquids should be able to accommodate changes in viscosity and density. The aim of this study was to develop a methodology for testing chemical injection systems using liquids with different viscosities. The experimental arrangement simulating applications with injection metering systems used dye and salt solutions as tracers. Tests were conducted to analyse the influence of salt on the characteristics of the water and a viscous solution. Results showed that the salt interfered with the dye stability in the water solution. In tests with a viscous test liquid, the salt was introduced at different steps during the mixing process, providing four different liquids to be analysed in terms of viscosity, density and pH. Some differences in liquid characteristics were found which could influence the performance of the injection systems.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The protonation of 4-dimethylaminobenzylidenepyruvate (DMBP) and 2-chloro-4-dimethylaminobenzylidenepyruvate (2-CI-DMBP) and their complex formation with Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Pb(II), Cd(II) and Al(III) have been studied by potentiometric and spectrophotometric methods at 25 °C and ionic strength 0.500 M, held with sodium perchlorate. The stability order found for 1 :1 complexes of both ligands is Al(III) > Cu(II) > Pb(II) > Ni(II) > Zn(II) > Co(II) > Cd(II) > Mn(II). The stability changes move in the same direction as the pKa of the ligands. The results are compared with literature values reported for metal ion pyruvate systems. Thermodynamic stabilities of ternary complexes formed in Cu(II)-B-L- systems, where B = 2,2′-bipyridyl (bipy), ethylenediamine or glycinate and L = DMBP or 2-CI-DMBP, were also determined. The Cu(bipy)L+ species are more stable than would be expected on purely statistical grounds. The importance of the :t system associated with bipy on the enhanced stability of its mixed ligand complexes is stressed. Analytical applications of the investigated ligands are outlined.

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A field experiment was conducted with chamomile (Chamomilla recutita [L.] Rauschert), in an area of the Olericulture and Medicinal Plants of the Horticulture Department at UNESP - Jaboticabal Campus, with the aim to evaluate the influence of organic and chemical fertilization on the yield of flowers, and content and composition of the essential oil of chamomile. The experimental design for the yield of flowers consisted of randomized blocks with 7 treatments and 4 replications, for the analysis of the contents and composition of the oil, the completely randomized block was used and for analysis of the correlation between harvesting and treatment, the split-plot design into randomized blocks was used. The treatments tested were: no fertilization, green manure (Mucuna aterrima + Crotalaria spectabilis), green manure (plant cocktail), organic fertilizer (farmyard manure), N as urea, N as ammonium sulphate, NPK with N supplement as ammonium sulphate. There was no influence of the treatments on the yield of flowers nor on the essential oil content; on the other hand both characteristics did show significant differences in harvesting times (Tukey 5%). The main yield was 885.90 kg/ha dry flowers and the mean oil content was 0,86%. The green manure treatment (M. aterrima + C. spectabilis) showed a higher percentage of chamazulene content, with a highly significant difference in harvesting times (Tukey 1%). The a-bisabolol percentages did not evidence significant differences between treatments. However, among harvesting times, there was a variation. A negative correlation was verified between the chamazulene and abisabolol percentages; the first increasing - from 21.02 to 36.17% - and the latter decreasing - from 14.12 to 8.72 % - from the first to the sixth harvest. The observed mean content of chamazulene was 14.64 % and a-bisabolol was 16.72 %.

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Managing the great complexity of enterprise system, due to entities numbers, decision and process varieties involved to be controlled results in a very hard task because deals with the integration of its operations and its information systems. Moreover, the enterprises find themselves in a constant changing process, reacting in a dynamic and competitive environment where their business processes are constantly altered. The transformation of business processes into models allows to analyze and redefine them. Through computing tools usage it is possible to minimize the cost and risks of an enterprise integration design. This article claims for the necessity of modeling the processes in order to define more precisely the enterprise business requirements and the adequate usage of the modeling methodologies. Following these patterns, the paper concerns the process modeling relative to the domain of demand forecasting as a practical example. The domain of demand forecasting was built based on a theoretical review. The resulting models considered as reference model are transformed into information systems and have the aim to introduce a generic solution and be start point of better practical forecasting. The proposal is to promote the adequacy of the information system to the real needs of an enterprise in order to enable it to obtain and accompany better results, minimizing design errors, time, money and effort. The enterprise processes modeling are obtained with the usage of CIMOSA language and to the support information system it was used the UML language.

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We investigate, from a philosophical perspective, the relation between abductive reasoning and information in the context of biological systems. Emphasis is given to the organizational role played by abductive reasoning in practical activities of embodied embedded agency that involve meaningful information. From this perspective, meaningful information is provisionally characterized as a selforganizing process of pattern generation that constrains coherent action. We argue that this process can be considered as a part of evolutionarily developed learning abilities of organisms in order to help with their survival. We investigate the case of inorganic mechanical systems (like robots), which deal only with stable forms of habits, rather than with evolving learning abilities. Some difficulties are considered concerning the hypothesis that mechanical systems may operate with meaningful information, present in abductive reasoning. Finally, an example of hypotheses creation in the domain of medical sciences is presented in order to illustrate the complexity of abduction in practical reasoning concerning human activities. © 2007 Springer-Verlag Berlin Heidelberg.

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This work presents the Petri net-based modeling of an autonomous robot's navigation system used for the application of supplies in agriculture. The model was developed theoretically and implemented through the CPNTools software. It simulates the behavior of the robot, capturing environmental characteristics by means of sensors, making appropriate decisions, and forwarding them to the corresponding actuators. By exciting the model using CPNTools it is possible to simulate situations that the robot might undergo, without the need to expose it to real potentially dangerous situations. ©2009 IEEE.

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Study objective was to evaluate economically a Nile tilapia juvenile production, employing different feeding techniques. Tilapia fingerlings of 8g were stocked at 5 fish m-2 stocking in 50 and 150 m2 ponds, during 75 days. Treatments were: inorganic fertilization (P205 and N); organic fertilization (poultry manure) and commercial ration (32% CP). Water quality results were considered adequate for fish rearing. In juvenile production there were significant differences among treatments for individual final weight, medians were: for inorganic fertilization 12.92g (13.35g in 50 m2 and 12.49g in 150 m2); for organic fertilization 30.55g (33.69g in 50 m2 and 27.40g in 150 m2) and for commercial ration 51.23g (52.90g in 50 m2 and 50.15g in 150 m2). Survival rate ranged from 63 to 71%, with no statistic difference. Commercial ration was effective to bigger juvenile production, with a better market value. Costs considered in economic analyses were tilapia fingerlings, fertilizer, ration, labor and installation depreciation. Obtained information showed that juvenile production in 50 m2 ponds is not viable economically and, in 150 m2, production is viable only when commercial ration is used.

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The cost of maintenance makes up a large part of total energy costs in ruminants. Metabolizable energy (ME) requirement for maintenance (MEm) is the daily ME intake that exactly balances heat energy (HE). The net energy requirement for maintenance (NEm) is estimated subtracting MEm from the HE produced by the processing of the diet. Men cannot be directly measured experimentally and is estimated by measuring basal metabolism in fasted animals or by regression measuring the recovered energy in fed animals. MEm and NEm usually, but not always, are expressed in terms of BW0.75. However, this scaling factor is substantially empirical and its exponent is often inadequate, especially for growing animals. MEm estimated by different feeding systems (AFRC, CNCPS, CSIRO, INRA, NRC) were compared by using dairy cattle data. The comparison showed that these systems differ in the approaches used to estimate MEm and for its quantification. The CSIRO system estimated the highest MEm, mostly because it includes a correction factor to increase ME as the feeding level increases. Relative to CSIRO estimates, those of NRC, INRA, CNCPS, and AFRC were on average 0.92, 0.86, 0.84, and 0.78, respectively. MEm is affected by the previous nutritional history of the animals. This phenomenon is best predicted by dynamic models, of which several have been published in the last decades. They are based either on energy flows or on nutrient flows. Some of the different approaches used were described and discussed.

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Influence of cutting instruments and The aim of this study was to analyze the hybrid layer in noncarious dentin prepared by different cutting instruments and restored with composite resin. The cavities were randomly prepared in 40 specimens using a high-speed diamond bur (KG Sorensen 1013) and an ultrasonic tip (CVDentus C22). The cavities were restored with composite resin by varying the adhesive system between the Adper™ Single Bond (2 x 1 system, primer+adhesive) and the Prompt L-Pop™ (3 x 1 system, self-etching). The restorations were hemisected longitudinally and analyzed in the SEM (Scanning electron microscopy) in order to evaluate the hybrid layer and resinous tags characteristics, using scores ranging from 1 to 6. The Pearson test revealed a high correlation coefficient and good significance levels for both intra- and inter-raters values (r=0.90). The data were statistically analyzed using the Mann-Whitney test (P≤0.05). A larger proportion of regular hybrid layers with numerous tags were observed in the dentin prepared using the high-speed diamond burs and restored with a 2 × 1 adhesive system. Alternatively, the 3 × 1 adhesive system promoted the generation of a thin hybrid layer with few tags. After preparation using an ultrasonic tip revealed few or no tags after the preparation and 2 × 1 or 3 × 1 adhesive system application. The high-speed diamond burs produced a dentin surface that was more favorable to restorative material adhesion than the ultrasonic tips, regardless of the adhesive system used.

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In the present study, the composition of essential oil of leaves and inflorescences of jambu (Spilanthes oleracea. Jambuarana), under organic manuring and mineral fertilization, was stuhed. Jambu plants show important chemical properties and their production has been addressed for the extraction of the essential oils for cosmetics industries, due to their pharmacolopcal properties. The experimental area of treatments contained urea as mineral fertilizer (120 g m2), applied twice and organic fertilizer (8 kg m2), applied at the planting. Jambu leaves and flowers were harvested twice: the first at 90 days after seedling transplantation and at the opening of the flower buds. Branches were cut at 7 cm from the soil, thus new branches can bud for the accomplishment of the second crop which happened 40 days after the re-budhng. The essential oil was analyzed by gas chromatography coupled with mass-spectrometry. According to our results the most representative compounds were trans-caryophyllene, germacrene-D, 1-dodecene, spathulenol and spilanthol (a compound presenting anesthetic properties) occurring in inflorescences. Fertilization procedure does not affect the content and the quality of the essential oil in Jambu plants. © 2012 Academic Journals Inc.

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This research was conducted with objective to evaluate the effect of different zinc (Zn) sources and doses in the diet for Santa Ines sheep. Forty lambs at weaning, with 18.4 kg of body weight were supplemented with three different sources of zinc (zinc oxide (ZnO), zinc amino acid and zinc proteinate) and three doses of zinc (200, 400 and 600 mg/kg DM) added to the basal diet. At every 28 days, animals were weighted and blood samples were collected for analyses of zinc (Zn), alkaline phosphatase and immunoglobulin G (IgG) and M (IgM). At the end of experiment, liver samples were collected for determination of the hepatic zinc levels. Zinc was analyzed with atomic absorption spectrophotometer, while phosphatase alkaline and immunoglobulins G and M were analyzed using Laborlab and Bioclin kits, respectively. There was no effect of diets on phosphatase alkaline levels and hepatic zinc, but there was difference in the plasmatic zinc levels and IgG and IgM levels. Based on the accumulation of hepatic zinc, the estimate of the zinc bioavailability, through the regression equation, showed that supplementation with organic and inorganic sources of zinc did not differ in the diet of Santa Ines sheep. © 2012 Sociedade Brasileira de Zootecnia.

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While searching for healthier diets, people became more attentive to organic produce. Yet, organic foods may be more susceptible to microbiological contamination because of the use of organic fertilizers, a possible source of pathogenic bacteria. In this study, 130 samples of different organic and conventional vegetable varieties sold in Brazil were analyzed for mesophilic aerobic bacteria, yeasts and molds, total coliforms, Escherichia coli and Salmonella spp. Most of the mesophilic aerobic bacteria counts in organic and conventional vegetables ranged from 6 to 7 log10 CFU/g; most of the yeasts and molds counts ranged from 5 to 6 log10 CFU/g and most of the total coliforms counts ranged from 4 to 5 log10 CFU/g. E. coli was found in 41.5% of the organic and 40.0% of the conventional vegetables, and most samples had counts ranging from 1 to 2 log10 CFU/g. Salmonella spp. was not found in any sample. Comparative analyses of the microbial counts of organic and conventional vegetables showed that some organic varieties have greater counts. However, the global results show that this is not a trend. These results indicate the need of good farming practices, and proper sanitization before consumption, to ensure food quality and safety. © 2012 Elsevier Ltd.

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The limited availability of foods that are free of pesticides has led Brazil to search for alternative production methods to meet the desires of consumers. Currently, organic cultivation represents a production system that complies with general expectations of producers and consumers. Organic cultivation is particularly interesting mainly because of its effect on plant secondary metabolite content, which may help plants to naturally combat pests; in humans, these substances can also contribute to the prevention of chronic diseases. We report on the extraction of glucosinolates (both as total glucosinolates and as benzylglucosinolate) with trifluoroacetic acid addition in a 70:30 MeOH:water (v/v). Total glucosinolates, determined by a thioglucosidase coupled assay, were measured in different Brassicaceae species and were similar to values reported in the literature. For broccoli, analyses were carried out separately on inflorescences, leaves and stalks; analyses were also conducted on thermally processed samples to simulate cooking. Furthermore, when the analysis was conducted on conventional and organic products, the highest concentrations of these substances were most often found in organically cultivated Brassicaceae. The benzylglucosinolate concentrations were evaluated on the same samples using HPLC. The concentration of benzylglucosinolate was significantly higher in organically cultivated vegetables, as well. © 2012 Elsevier Ltd.