96 resultados para capacity check
Resumo:
The objective of this work was to evaluate the biochemical composition of six berry types belonging to Fragaria, Rubus, Vaccinium and Ribes genus. Fruit samples were collected in triplicate (50 fruit each) from 18 different species or cultivars of the mentioned genera, during three years (2008 to 2010). Content of individual sugars, organic acids, flavonols, and phenolic acids were determined by high performance liquid chromatography (HPLC) analysis, while total phenolics (TPC) and total antioxidant capacity (TAC), by using spectrophotometry. Principal component analysis (PCA) and hierarchical cluster analysis (CA) were performed to evaluate the differences in fruit biochemical profile. The highest contents of bioactive components were found in Ribes nigrum and in Fragaria vesca, Rubus plicatus, and Vaccinium myrtillus. PCA and CA were able to partially discriminate between berries on the basis of their biochemical composition. Individual and total sugars, myricetin, ellagic acid, TPC and TAC showed the highest impact on biochemical composition of the berry fruits. CA separated blackberry, raspberry, and blueberry as isolate groups, while classification of strawberry, black and red currant in a specific group has not occurred. There is a large variability both between and within the different types of berries. Metabolite fingerprinting of the evaluated berries showed unique biochemical profiles and specific combination of bioactive compound contents.
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The objective of this work was to produce a polyclonal antiserum against the coat protein (CP) of Papaya lethal yellowing virus (PLYV) and to determine its specificity and sensibility in the diagnosis of the virus, as well as to evaluate the genetic resistance to PLYV in papaya (Carica papaya) accessions and to investigate the capacity of the two-spotted spider mite Tetranychus urticae to acquire and transmit PLYV to the plants. Sixty-five papaya accessions were evaluated. For each accession, ten plants were mechanically inoculated using PLYV-infected plant extracts, and three plants were mock inoculated with phosphate buffer alone and used as negative controls. Ninety days after inoculation, newly-emerging systemic leaves were collected from the inoculated plants, and viral infection was diagnosed by indirect Elisa, using polyclonal antiserum sensible to the in vitro-expressed PLYV CP. Viral transmission by T. urticae was evaluated in greenhouse. The experiments were repeated twice. Polyclonal antiserum recognized the recombinant PLYV CP specifically and discriminated PLYV infection from infections caused by other plant viruses. Out of the 65 papaya accessions evaluated, 15 were considered resistant, 18 moderately resistant, and 32 susceptible. The two-spotted spider mite T. urticae was capable of acquiring PLYV, but not of transmitting it to papaya.
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The objective of the present study was to characterize the chemistry and the antioxidant capacity in 8 species of native fruits from Amazonia. All the fruits were collected at full physiological and commercial maturity from properties located at: Boa Vista / RR, São Luiz do Anauá / RR, Manaus / AM, and Belém / PA. At the end of the experiment, the functional pattern for the camu-camu fruits showed that the total phenolic and ascorbic acid content and antioxidant assays were superior compared to the other samples. Despite the functional losses detected for the freeze-dried samples of the camu-camu fruit, all the other freeze-dried samples kept under -20ºC showed appropriate stability for long-term storage. In addition, it was also observed that fruit peel showed higher antioxidant activity than pulp or samples containing peel and pulp tissues in the same extract. When the ratio between the ORAC and total phenolic assays were observed, the uxi fruit demonstrated the highest antioxidant power compared to the other fruits studied, despite its relatively low levels of phenolic compound content and ORAC values. This means that there is a relevant contribution of these phenolic compounds to the antioxidant activity of uxi fruit.
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The microwave oven became a common domestic equipment, due mainly to the short time spent to heat foods. One of the most interesting characteristics of the microwave oven is the selective heating. Different from the conventional oven, where the heating is not selective, the heating by microwave depends on the chemical nature of the matter. Many Students of Chemistry have no knowledge of the principles involved in this selective heating, in spite of the daily microwave oven use. The heating by microwave is feasible for chemistry courses. In discussions about the microwave absorption by the matter it is possible to explore chemical properties like: heat capacity, chemical bound, molecular structure, dipole moments, polarization and dielectric constant. This paper presents the basic principles involved in the microwave heating. It is proposed a simple and inexpensive experiment that could be developed in general chemistry courses, to illustrate the relationship between heating and the chemical properties of some solvents. Experiments to check the power of the microwave oven are also proposed.
Resumo:
Toxicity and antioxidant capacity of eugenol derivatives (E2 = 2-Methoxy-4-[1-propenylphenyl]acetate, E3 = 4-Allyl-2-methoxyphenylacetate, E4 = 4-Allyl-2-methoxy-4-nitrophenol, E5 = 5-Allyl-3-nitrobenzene-1,2-diol, E6 = 4-Allyl-2-methoxy-5-nitrophenyl acetate) were evaluated in order to determine the influence of the sustituents. E2-E6 were synthesized from eugenol (E1). E1 was extracted from cloves oil, and E2-E6 were obtained through acetylation and nitration reactions. Antioxidant capacity evaluated by DPPH (1, 1-Diphenyl-2-picrylhydrazil) and ORAC fluorescein demonstrated that E1 and E5 have a higher capacity and the minor toxicity evaluated by red blood cells haemolysis and the Artemia saline test. In accordance with our results, the compound's (E1-E5) use in the pharmaceutical, cosmetic and or food industries could be suggested.
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The polyphenol contents and antioxidant capacity of Brazilian red grape juices and wine vinegars were analyzed. Additionally, it was analyzed the human polyphenol absorption and acute effect in plasmatic oxidative metabolism biomarkers after juice ingestion. The organic Bordo grape juice (GBO) presented a higher level of trans-resveratrol, quercitin, rutin, gallic acid, caffeic acid and total flavonoids then other juices and vinegars as well as antioxidant capacity. The plasmatic polyphenol increased 27.2% after GBO juice ingestion. The results showed that juices and vinegars from Brazilian crops present similar chemical and functional properties described in studies performed in other countries.
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The content of isoorientin in passion fruit rinds (Passiflora edulis fo. flavicarpa O. Degener) was determined by HPTLC (high performance thin layer chromatography) with densitometric analysis. The results revealed a higher amount of isoorientin in healthy rinds of P. edulis (92.275 ± 0.610 mg L-1) than in rinds with typical symptoms of PWV (Passion fruit Woodiness Virus) infection (28.931 ± 0.346 mg L-1). The HPTLC data, allied to assays of radical scavenging activity, suggest the potential of P. edulis rinds as a natural source of flavonoids or as a possible functional food.
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The present paper focuses on improving chromium (III) uptake capacity of sugarcane bagasse through its chemical modification with citric acid and/or sodium hydroxide. The chemical modifications were confirmed by infrared spectroscopy, with an evident peak observed at 1730 cm-1, attributed to carbonyl groups. Equilibrium was reached after 24 h, and the kinetics followed the pseudo-second-order model. The highest chromium (III) maximum adsorption capacity (MAC) value was found when using sugarcane bagasse modified with sodium hydroxide and citric acid (58.00 mg g-1) giving a MAC value about three times greater (20.34 mg g-1) than for raw sugarcane bagasse.
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The efficiency of the chemiluminescence luminol method and colorimetric DPPH and ABTS methods in evaluating the antiradical capacity of pure compounds and plant extracts with antioxidant potential is compared. In case of pure compounds, the values of parameter 'n' (number of radicals quenched per molecule of antiradical) for ascorbic acid, p-hydroquinone, catechol, quercetin, and rutin are similar when measured by colorimetric assays; however, considerably lower values of n are obtained with the luminol assay. The antiradical activity of extracts from male and female individuals of Baccharis burchelli and Baccharis crispa were determined by the luminol assay and expressed using the new Trolox® percentage (%Trolox®) parameter.
Resumo:
An activated carbon was obtained by chemical activation with phosphoric acid, CM, from a mineral carbon. Afterwards, the carbon was modified with 2 and 5 molL-1, CMox2 and CMox5 nitric acid solutions to increase the surface acid group contents. Immersion enthalpy at pH 4 values and Pb2+ adsorption isotherms were determined by immersing activated carbons in aqueous solution. The surface area values of the adsorbents and total pore volume were approximately 560 m².g-1 and 0.36 cm³g-1, respectively. As regards chemical characteristics, activated carbons had higher acid sites content, 0.92-2.42 meq g-1, than basic sites, 0.63-0.12 meq g-1. pH values were between 7.4 and 4.5 at the point of zero charge, pH PZC. The adsorbed quantity of Pb2+ and the immersion enthalpy in solution of different pH values for CM activated carbon showed that the values are the highest for pH 4, 15.7 mgg-1 and 27.6 Jg-1 respectively. Pb2+ adsorption isotherms and immersion enthalpy were determined for modified activated carbons and the highest values were obtained for the activated carbon that showed the highest content of total acid sites on the surface.
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Five flavanones and three chalcones were isolated from Campomanesia adamantium Berg. (Myrtaceae) leaves. The contents of these compounds were determined by HPLC. The phenolic contents were also determined. The monitoring of the antioxidant activity was carried out by inhibition of peroxidation using the linoleic acid system and radical-scavenging (DPPH). The plants were collected from 4 distinct cities of the Mato Grosso do Sul State, Brazil. The different samples exhibited a range of 4.67-232.35 mg/g chalcones and 15.62-50.71 mg/g flavanones and phenolic contents of the 7.24-21.19 mg/g gallic acid. All extracts showed high antioxidant activity with a wide range of the radical-scavenging (DPPH) from 52.0 to 92.2 % and inhibition oxidation of linoleic acid from 14.6 to 94.2%.
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RESUMOEste estudo teve como objetivo principal avaliar, qualitativa e quantitativamente, os impactos ambientais de um programa de fomento florestal, por meio do método da matriz de interação, coadjuvado por uma lista de verificação complementar, conhecida como método do check-list. Verificou-se, também, a aplicabilidade e complementaridade desses métodos para este caso. O referido programa foi realizado na região de influência do Polo Moveleiro de Ubá, na Zona da Mata mineira. O método da matriz de interação identificou 473 impactos, sendo 172 positivos (36,4%) e 301 negativos (63,6%), enquanto o método do check-list identificou 94 impactos, sendo 34 positivos (36,2%) e 60 negativos (63,8%). Concluiu-se que o referido programa possui impactos ambientais negativos e positivos, numa proporção de cerca de dois para um, respectivamente, bem como que os métodos usados se mostraram eficientes para a situação verificada, uma vez que foram capazes de identificar e descrever, em plenitude, tais impactos ambientais e de forma complementar.
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It is presented a software developed with Delphi programming language to compute the reservoir's annual regulated active storage, based on the sequent-peak algorithm. Mathematical models used for that purpose generally require extended hydrological series. Usually, the analysis of those series is performed with spreadsheets or graphical representations. Based on that, it was developed a software for calculation of reservoir active capacity. An example calculation is shown by 30-years (from 1977 to 2009) monthly mean flow historical data, from Corrente River, located at São Francisco River Basin, Brazil. As an additional tool, an interface was developed to manage water resources, helping to manipulate data and to point out information that it would be of interest to the user. Moreover, with that interface irrigation districts where water consumption is higher can be analyzed as a function of specific seasonal water demands situations. From a practical application, it is possible to conclude that the program provides the calculation originally proposed. It was designed to keep information organized and retrievable at any time, and to show simulation on seasonal water demands throughout the year, contributing with the elements of study concerning reservoir projects. This program, with its functionality, is an important tool for decision making in the water resources management.
Resumo:
ABSTRACT The objective of this study was to evaluate the thermoregulatory response of dairy buffaloes in pre-milking and post-milking. To identify animal thermoregulatory capacity, skin surface temperatures were taken by an infrared thermometer (SST), a thermographic camera (MTBP) as well as respiratory rate records (RR). Black Globe and Humidity Index (BGHI), radiating thermal load (RTL) and enthalpy (H) were used to characterize the thermal environment. Artificial Neural Networks analyzed those indices as well as animal physiological data, using a single layer trained with the least mean square (LMS) algorithm. The results indicated that pre-milking and post-milking environments reached BGHI, RR, SST and MTBP values above thermal neutrality zone for buffaloes. In addition, limits of surface skin temperatures were mostly influenced by changing ambient conditions to the detriment of respiratory rates. It follows that buffaloes are sensitive to environmental changes and their skin temperatures are the best indicators of thermal comfort in relation to respiratory rate.
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ABSTRACT Understanding the critical period of weed competition is indispensable in the development of an effective weed management program in field crops. Current experiment was planned to evaluate the critical growth period ofSetaria and level of yield losses associated with delay in weeding in rain-fed drip irrigated wheat production system of Saudi Arabia. Field experiment was conducted to evaluate the effect of weeding interval (07-21, 14-28, 21-35, 28-42 and 35-49 days after sowing) and drought stress (75% and 50% of field capacity) on Setaria growth, wheat yield and water use efficiency. Season long weedy check and wellwatered (100% FC) plots were also maintained for comparison. Weeding interval and drought stress significantly (p ≤ 0.05) affected the growth and yield of Setaria and wheat. Drought stress from 75% to 50% FC resulted in reductions of 29-40% in Setaria height, 14-27% in Setaria density and 11-26% in Setaria dry biomass. All weeding intervals except 35-49 DAS significantly suppressedSetaria growth as compared with control. Delay in weeding increased weed-crop competition interval and reduced wheat yield and yield contributors. Therefore, the lowest yield of 1836 kg ha-1 was attained for weeding interval of 35-49 DAS at 50% FC. Water use efficiency and harvest index increased with decreasing FC levels but reduced with delay in weeding. Correlation analysis predicted negative association ofSetariadensity with wheat yield and yield contributors and the highest negative association was for harvest index (-0.913) and water use efficiency (-0.614). Early management of Setaria is imperative for successful wheat production otherwise yield losses are beyond economical limits.