878 resultados para WWW application


Relevância:

30.00% 30.00%

Publicador:

Resumo:

Polymers from natural sources are particularly useful as biomaterials for medical devices applications. In this study, the results of characterization of a gelatin network electrolyte doped with europium triflate (Eu(CF3SO3)(3)) are described. The unusual electronic properties of the trivalent lanthanide ions make them well suited as luminescent reporter groups, with many applications in biotechnology. Samples of solvent-free electrolytes were prepared with a range of guest salt concentration. Materials based on Eu(CF3SO3)(3) were obtained as mechanically robust, flexible, transparent, and completely amorphous films. Samples were characterized by thermal analysis (thermo-gravimetry analysis (TGA) and differential scanning calorimetry (DSC), electrochemical stability, scanning electronmicroscopy (SEM), and photoluminescence spectroscopy.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Current SoC design trends are characterized by the integration of larger amount of IPs targeting a wide range of application fields. Such multi-application systems are constrained by a set of requirements. In such scenario network-on-chips (NoC) are becoming more important as the on-chip communication structure. Designing an optimal NoC for satisfying the requirements of each individual application requires the specification of a large set of configuration parameters leading to a wide solution space. It has been shown that IP mapping is one of the most critical parameters in NoC design, strongly influencing the SoC performance. IP mapping has been solved for single application systems using single and multi-objective optimization algorithms. In this paper we propose the use of a multi-objective adaptive immune algorithm (M(2)AIA), an evolutionary approach to solve the multi-application NoC mapping problem. Latency and power consumption were adopted as the target multi-objective functions. To compare the efficiency of our approach, our results are compared with those of the genetic and branch and bound multi-objective mapping algorithms. We tested 11 well-known benchmarks, including random and real applications, and combines up to 8 applications at the same SoC. The experimental results showed that the M(2)AIA decreases in average the power consumption and the latency 27.3 and 42.1 % compared to the branch and bound approach and 29.3 and 36.1 % over the genetic approach.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This article studied the applicability of poly(acrylamide) and methylcellulose (PAAm-MC) hydrogels as potential delivery vehicle for the controlled-extended release of ammonium sulfate (NH(4))(2)SO(4) and potassium phosphate (KH(2)PO(4)) fertilizers. PAAm-MC hydrogels with different acrylamide (AAm) and MC concentrations were prepared by a free radical polymerization method. The adsorption and desorption kinetics of fertilizers were determined using conductivity measurements based on previously built analytical curve. The addition of MC in the PAAm chains increased the quantities of (NH(4))(2)SO(4) and KH(2)PO(4) loaded and extended the time and quantities of fertilizers released. Coherently, both loading and releasing processes were strongly influenced by hydrophilic properties of hydrogels (AAm/MC mass proportion). The best sorption (124.0 mg KH(2)PO(4)/g hydrogel and 58.0 mg (NH(4))(2)SO(4)/g hydrogel) and desorption (54.9 mg KH(2)PO(4)/g hydrogel and 49.5 mg (NH(4))(2)SO(4)/g hydrogel) properties were observed for 6.0% AAm-1.0% MC hydrogels (AAm/MC mass proportion equal 6), indicating that these hydrogels are potentially viable to be used in controlled-extended release of fertilizers systems. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 123: 2291-2298, 2012

Relevância:

30.00% 30.00%

Publicador:

Resumo:

A new series of donor acceptor copolymers were synthesized via the Witting route and applied as an active layer in organic thin-films solar cells. These copolymers are composed of fluorene thiophene and phenylene thiophene units. The ratio between those was systematically varied, and copolymers containing 0%, 50%, and 75% of phenylene thiophene were characterized and evaluated when used in photovoltaic devices. The copolymers' composition, photophysical, electrical, and morphological properties are addressed and correlated with device performance. The 50% copolymer ratio was found to be the best copolymer of the series, yielding a power conversion efficiency (PCE) under air mass (AM) 1.5 conditions of 2.4% in the bilayer heterojunction with the C-60 molecule. Aiming at flexible electronics applications, solutions based on the heterojunction of this copolymer with PCBM (6,6-phenyl-C-61-butyric acid methyl ester) were also successfully deposited using an inkjet printing method and used as an active layer in solar cells.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

We investigate the strong magnetic and gravity anomalies of the Goias Alkaline Province (GAP), a region of Late Cretaceous alkaline magmatism along the northern border of the Parana Basin, Brazil. The alkaline complexes (eight of which are present in outcrops, two others inferred from magnetic signals) are characterized by a series of small intrusions forming almost circular magnetic and gravimetric anomalies varying from -4000 to +6000 nT and from -10 to +40 mGal, respectively. We used the Aneuler method and Analytical Signal Amplitude to obtain depth and geometry for mapped sources from the magnetic anomaly data. These results were used as the reference models in the 3D gravity inversion. The 3D inversion results show that the alkaline intrusions have depths of 10-12 km. The intrusions in the northern GAP follow two alignments and have different sizes. In the anomaly magnetic map, dominant guidelines correlate strongly with the extensional regimes that correlate with the rise of alkaline magmatism. The emplacement of these intrusions marks mechanical discontinuities and zones of weakness in the upper crust. According to the 3D inversion results, those intrusions are located within the upper crust (from the surface to 18 km depth) and have spheres as the preferable geometry. Such spherical shapes are more consistent with magmatic chambers instead of plug intrusions. The Registro do Araguaia anomaly (similar to 15 by 25 km) has a particular magnetic signature that indicates that the top is deeper than 1500 m. North of this circular anomaly are lineaments with structural indices indicating contacts on their edges and dikes/sills in the interiors. Results of 3D inversion of magnetic and gravity data suggest that the Registro do Araguaia is the largest body in the area, reaching 18 km depth and indicating a circular layered structure. (C) 2011 Elsevier Ltd. All rights reserved.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

In a field experiment performed in Lins County (Sao Paulo State, Brazil), treated sewage effluent (TSE) irrigation increased sugarcane yield but caused an excessive increase in the exchangeable sodium percentage (ESP) and clay dispersion after 16 months due to an intense irrigation regime (2500 mm/16 months) with sodium rich effluents. After two additional complete cycles with lower TSE irrigation rates (1200 mm year(-1)), 1700 kg ha(-1) of phosphogypsum was added to a section of the irrigated plots to evaluate its residence time and its implications on Na+ dynamics and other soil properties. Undisturbed soil cores were taken 2 years after phosphogypsum application to verify soil physical properties up to 0.2 m depth, and disturbed soil samples were taken every year up to 1 m depth for chemical analyses. After 5 years of consecutive TSE irrigation (2005-2010), soil acidity (pH approximate to 5) and basic cations (Ca approximate to 12, Mg approximate to 6 and K approximate to 2 mmol(c) kg(-1)) were maintained in adequate conditions for plant development without the necessity of liming, while acidity was increased (pH approximate to 4.5) and Ca (approximate to 9 mmol(c) kg(-1)), and the Mg (approximate to 4.5 mmol(c) kg(-1)) concentration decreased in the rainfed without phosphogypsum treatment. An increase in water retention capacity at -30 (from 0.14 to 0.17 m(3) m(-3)) and -1500 kPa (from 0.08 to 0.12 m(3) m(-3)) potentials was also observed in all TSE irrigated treatments. The plots with a phosphogypsum treatment showed average increases of 2 mmol(c) kg(-1) of Ca2+ and 7 mg kg(-1) of S-SO42- in all soil profiles and an average reduction of 2 mmol(c) kg(-1) of Na+ up to 0.4 m from 2008 to 2009. However, the extent of the chemical effects was greater after the first year compared to the second year. The high concentration of Na+ found in previous studies performed in the same area returned to low concentrations after continued TSE irrigation at lower rates, even without the phosphogypsum application. An unusual phosphorus migration was observed to the 0.4-0.8 m soil layer as a result of TSE irrigation, most likely due to a high pH and a Na carbonate-dominated TSE. (C) 2012 Elsevier B.V. All rights reserved.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Aims and objectives. To compare the effect of an ice pack applied for 10, 15 and 20 minutes to relieve perineal pain after birth. Background. Perineal pain after vaginal birth, with or without vaginal trauma, is one of the most common morbidities reported for postnatal women. Cryotherapy has been used in postpartum period to relieve perineal pain and investigated in several studies. However, cryotherapy treatment protocols in perineal care vary widely regarding temperature, frequency and duration of the application. Design. A controlled trial, randomised for two groups and with a third group as a historical control. Method. The intervention was carried out in a maternity hospital in Sao Paulo, Brazil. The study population consisted of three groups of 38 women who used an ice pack on the perineum, in a single application: group A-10 minutes; group B-15 minutes; group C-20 minutes (historical control from another clinical trial). Participants perineal pain magnitude was evaluated through a numerical scale (010), at four different points: before the cryotherapy; immediately after and at 20 and 40 minutes after cryotherapy. Results. After application of the ice pack, there was no statistical difference when comparing the perineal pain among groups in the second, third and fourth evaluations. Most of the postnatal women reported pain relief, with 72.8% reporting a decrease in pain >50%; 21.9% reported a decrease between 3050%. All postnatal women subjected to cryotherapy were favourable to the procedure. Conclusion. There is no difference in pain scores following ice pack application in three different times (10, 15 and 20 minutes) in women who report moderate or intense perineal pain after normal delivery. Relevance for clinical practice. Ice treatment is safe, and application times of 10 or 15 minutes are as beneficial as an application time of 20 minutes to relieve perineal pain.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

We investigate the occurrence of the optical Kerr effect and two-photon absorption when an oil-based magnetic Fe3O4 nanoparticles colloidal suspension is illuminated with high intensity femtosecond laser pulses. The frequency of the pulses is controlled and the Z-scan technique is employed in our measurements of the nonlinear optical Kerr coefficient (n(2)) and two-photon absorption coefficient (beta). From these values it was possible to calculate the real and imaginary parts of the third-order susceptibility. We observed that increasing the pulse frequency, additional physical processes take place, increasing artificially the absolute values of n(2) and beta. The experimental conditions are discussed to assure the obtention of reliable values of these nonlinear optical parameters, which may be useful in all-optical switching and optical power limiting applications. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4723829]

Relevância:

30.00% 30.00%

Publicador:

Resumo:

A common interest in gene expression data analysis is to identify from a large pool of candidate genes the genes that present significant changes in expression levels between a treatment and a control biological condition. Usually, it is done using a statistic value and a cutoff value that are used to separate the genes differentially and nondifferentially expressed. In this paper, we propose a Bayesian approach to identify genes differentially expressed calculating sequentially credibility intervals from predictive densities which are constructed using the sampled mean treatment effect from all genes in study excluding the treatment effect of genes previously identified with statistical evidence for difference. We compare our Bayesian approach with the standard ones based on the use of the t-test and modified t-tests via a simulation study, using small sample sizes which are common in gene expression data analysis. Results obtained report evidence that the proposed approach performs better than standard ones, especially for cases with mean differences and increases in treatment variance in relation to control variance. We also apply the methodologies to a well-known publicly available data set on Escherichia coli bacterium.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

In the last few years, the European Union (EU) has become greatly concerned about the environmental costs of road transport in Europe as a result of the constant growth in the market share of trucks and the steady decline in the market share of railroads. In order to reverse this trend, the EU is promoting the implementation of additional charges for heavy goods vehicles (HGV) on the trunk roads of the EU countries. However, the EU policy is being criticised because it does not address the implementation of charges to internalise the external costs produced by automobiles and other transport modes such as railroad. In this paper, we first describe the evolution of the HGV charging policy in the EU, and then assess its practical implementation across different European countries. Second, and of greater significance, by using the case study of Spain, we evaluate to what extent the current fees on trucks and trains reflect their social marginal costs, and consequently lead to an allocative-efficient outcome. We found that for the average case in Spain the truck industry meets more of the marginal social cost produced by it than does the freight railroad industry. The reason for this lies in the large sums of money paid by truck companies in fuel taxes, and the subsidies that continue to be granted by the government to the railroads.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

An high performance liquid chromatography (HPLC) method for the enantioselective determination of donepezil (DPZ), 5-O-desmethyl donepezil (5-ODD), and 6-O-desmethyl donepezil (6-ODD) in Czapek culture medium to be applied to biotransformation studies with fungi is described for the first time. The HPLC analysis was carried out using a Chiralpak AD-H column with hexane/ethanol/methanol (75:20:5, v/v/v) plus 0.3 % triethylamine as mobile phase and UV detection at 270 nm. Sample preparation was carried out by liquid-liquid extraction using ethyl acetate as extractor solvent. The method was linear over the concentration range of 100-10,000 ng mL(-1) for each enantiomer of DPZ (r a parts per thousand yenaEuro parts per thousand 0.9985) and of 100-5,000 ng mL(-1) for each enantiomer of 5-ODD (r a parts per thousand yenaEuro parts per thousand 0.9977) and 6-ODD (r a parts per thousand yenaEuro parts per thousand 0.9951). Within-day and between-day precision and accuracy evaluated by relative standard deviations and relative errors, respectively, were lower than 15 % for all analytes. The validated method was used to assess DPZ biotransformation by the fungi Beauveria bassiana American Type Culture Collection (ATCC) 7159 and Cunninghamella elegans ATCC 10028B. Using the fungus B. bassiana ATCC 7159, a predominant formation of (R)-5-ODD was observed while for the fungus C. elegans ATCC 10028B, DPZ was biotransformed to (R)-6-ODD with an enantiomeric excess of 100 %.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Statistical methods have been widely employed to assess the capabilities of credit scoring classification models in order to reduce the risk of wrong decisions when granting credit facilities to clients. The predictive quality of a classification model can be evaluated based on measures such as sensitivity, specificity, predictive values, accuracy, correlation coefficients and information theoretical measures, such as relative entropy and mutual information. In this paper we analyze the performance of a naive logistic regression model (Hosmer & Lemeshow, 1989) and a logistic regression with state-dependent sample selection model (Cramer, 2004) applied to simulated data. Also, as a case study, the methodology is illustrated on a data set extracted from a Brazilian bank portfolio. Our simulation results so far revealed that there is no statistically significant difference in terms of predictive capacity between the naive logistic regression models and the logistic regression with state-dependent sample selection models. However, there is strong difference between the distributions of the estimated default probabilities from these two statistical modeling techniques, with the naive logistic regression models always underestimating such probabilities, particularly in the presence of balanced samples. (C) 2012 Elsevier Ltd. All rights reserved.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

In this article, we propose a new Bayesian flexible cure rate survival model, which generalises the stochastic model of Klebanov et al. [Klebanov LB, Rachev ST and Yakovlev AY. A stochastic-model of radiation carcinogenesis - latent time distributions and their properties. Math Biosci 1993; 113: 51-75], and has much in common with the destructive model formulated by Rodrigues et al. [Rodrigues J, de Castro M, Balakrishnan N and Cancho VG. Destructive weighted Poisson cure rate models. Technical Report, Universidade Federal de Sao Carlos, Sao Carlos-SP. Brazil, 2009 (accepted in Lifetime Data Analysis)]. In our approach, the accumulated number of lesions or altered cells follows a compound weighted Poisson distribution. This model is more flexible than the promotion time cure model in terms of dispersion. Moreover, it possesses an interesting and realistic interpretation of the biological mechanism of the occurrence of the event of interest as it includes a destructive process of tumour cells after an initial treatment or the capacity of an individual exposed to irradiation to repair altered cells that results in cancer induction. In other words, what is recorded is only the damaged portion of the original number of altered cells not eliminated by the treatment or repaired by the repair system of an individual. Markov Chain Monte Carlo (MCMC) methods are then used to develop Bayesian inference for the proposed model. Also, some discussions on the model selection and an illustration with a cutaneous melanoma data set analysed by Rodrigues et al. [Rodrigues J, de Castro M, Balakrishnan N and Cancho VG. Destructive weighted Poisson cure rate models. Technical Report, Universidade Federal de Sao Carlos, Sao Carlos-SP. Brazil, 2009 (accepted in Lifetime Data Analysis)] are presented.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Background: The species of T. harzianum are well known for their biocontrol activity against many plant pathogens. However, there is a lack of studies concerning its use as a biological control agent against F. solani, a pathogen involved in several crop diseases. In this study, we have used subtractive library hybridization (SSH) and quantitative real-time PCR (RT-qPCR) techniques in order to explore changes in T. harzianum genes expression during growth on cell wall of F. solani (FSCW) or glucose. RT-qPCR was also used to examine the regulation of 18 genes, potentially involved in biocontrol, during confrontation between T. harzianum and F. solani. Results: Data obtained from two subtractive libraries were compared after annotation using the Blast2GO suite. A total of 417 and 78 readable EST sequence were annotated in the FSCW and glucose libraries, respectively. Functional annotation of these genes identified diverse biological processes and molecular functions required during T. harzianum growth on FSCW or glucose. We identified various genes of biotechnological value encoding to proteins which function such as transporters, hydrolytic activity, adherence, appressorium development and pathogenesis. Fifteen genes were up-regulated and sixteen were down-regulated at least at one-time point during growth of T. harzianum in FSCW. During the confrontation assay most of the genes were up-regulated, mainly after contact, when the interaction has been established. Conclusions: This study demonstrates that T. harzianum expressed different genes when grown on FSCW compared to glucose. It provides insights into the mechanisms of gene expression involved in mycoparasitism of T. harzianum against F. solani. The identification and evaluation of these genes may contribute to the development of an efficient biological control agent.