Comparison between frequency domain and time domain riser analysis

In the optimization or parametric analyses of risers, several configurations must be analyzed. It is laborious to perform time domain solutions for the dynamic analysis, since they are time-consuming tasks. So, frequency domain solutions appear to be a possible alternative, mainly in the early stages of a riser design. However, frequency domain analysis is linear and requires that nonlinear effects are treated. The aim of this paper is to present a possible way to treat some of these nonlinearities, using an iterative process together with an analytical correction, and compare the results of a frequency domain analysis with the those of a full nonlinear analysis. [DOI: 10.1115/1.4006149]

Purification, characterization and structural determination of chitinases produced by Moniliophthora perniciosa

The enzyme chitinase from Moniliophthora perniciosa the causative agent of the witches' broom disease in Theobroma cacao, was partially purified with ammonium sulfate and filtration by Sephacryl S-200 using sodium phosphate as an extraction buffer. Response surface methodology (RSM) was used to determine the optimum pH and temperature conditions. Four different isoenzymes were obtained: ChitMp I, ChitMp II, ChitMp III and ChitMp IV. ChitMp I had an optimum temperature at 44-73ºC and an optimum pH at 7.0-8.4. ChitMp II had an optimum temperature at 45-73ºC and an optimum pH at 7.0-8.4. ChitMp III had an optimum temperature at 54-67ºC and an optimum pH at 7.3-8.8. ChitMp IV had an optimum temperature at 60ºC and an optimum pH at 7.0. For the computational biology, the primary sequence was determined in silico from the database of the Genome/Proteome Project of M. perniciosa, yielding a sequence with 564 bp and 188 amino acids that was used for the three-dimensional design in a comparative modeling methodology. The generated models were submitted to validation using Procheck 3.0 and ANOLEA. The model proposed for the chitinase was subjected to a dynamic analysis over a 1 ns interval, resulting in a model with 91.7% of the residues occupying favorable places on the Ramachandran plot and an RMS of 2.68.

Detecting an abnormality in a recovery boiler using dynamic multivariate data analysis with parallel coordinate plots

Data visualization techniques are powerful in the handling and analysis of multivariate systems. One such technique known as parallel coordinates was used to support the diagnosis of an event, detected by a neural network-based monitoring system, in a boiler at a Brazilian Kraft pulp mill. Its attractiveness is the possibility of the visualization of several variables simultaneously. The diagnostic procedure was carried out step-by-step going through exploratory, explanatory, confirmatory, and communicative goals. This tool allowed the visualization of the boiler dynamics in an easier way, compared to commonly used univariate trend plots. In addition it facilitated analysis of other aspects, namely relationships among process variables, distinct modes of operation and discrepant data. The whole analysis revealed firstly that the period involving the detected event was associated with a transition between two distinct normal modes of operation, and secondly the presence of unusual changes in process variables at this time.

Dynamic texture analysis and segmentation using deterministic partially self-avoiding walks

Dynamic texture is a recent field of investigation that has received growing attention from computer vision community in the last years. These patterns are moving texture in which the concept of selfsimilarity for static textures is extended to the spatiotemporal domain. In this paper, we propose a novel approach for dynamic texture representation, that can be used for both texture analysis and segmentation. In this method, deterministic partially self-avoiding walks are performed in three orthogonal planes of the video in order to combine appearance and motion features. We validate our method on three applications of dynamic texture that present interesting challenges: recognition, clustering and segmentation. Experimental results on these applications indicate that the proposed method improves the dynamic texture representation compared to the state of the art.

ANALYSIS OF MANGROVE FOREST SUCCESSION, USING SEDIMENT CORES: A CASE STUDY IN THE CANANEIA-IGUAPE COASTAL SYSTEM, SAO PAULO-BRAZIL

Sediment cores are an essential tool for the analysis of the dynamics of mangrove succession. Coring was used to correlate changes in depositional environments and lateral sedimentary facies with discrete stages of forest succession at the Cananeia-Iguape Coastal System in southeastern Brazil. A local level successional pattern was examined based on four core series T1) a sediment bank; T2) a smooth cordgrass Spartina alterniflora bank; T3) an active mangrove progradation fringe dominated by Laguncularia racemosa, and; T4) a mature mangrove forest dominated by Avicennia schaueriana. Cores were macroscopically described in terms of color, texture, sedimentary structure and organic components. The base of all cores exhibited a similar pattern suggesting common vertical progressive changes in depositional conditions and subsequent successional colonization pattern throughout the forest. The progradation zone is an exposed bank, colonized by S. alterniflora. L. racemosa, replaces S. alterniflora as progradation takes place. As the substrate consolidates A. schaueriana replaces L. racemosa and attains the greatest structural development in the mature forest. Cores collected within the A. schaueriana dominated stand contained S. alterniflora fragments near the base, confirming that a smooth cordgrass habitat characterized the establishment and early seral stages. Cores provide a reliable approach to describe local-level successional sequences in dynamic settings subject to drivers operating on multiple temporal and spatial scales where spatial heterogeneity can lead to multiple equilibria and where similar successional end-points may be reached through convergent paths.

Archaeofacies Analysis: Using Depositional Attributes to Identify Anthropic Processes of Deposition in a Monumental Shell Mound of Santa Catarina State, Southern Brazil

In the coast of Santa Catarina State (southern Brazil), a large population of monumental shell mounds characterizes a highly dynamic coastal setting. In this paper, sedimentary facies analysis was adapted for description, sampling, and interpretation of shell mound complex and repetitive archaeostratigraphic successions. Archaeofacies identification in the field, according to depositional attributes, is tested by contrasting field description with multi-element chemical analyses, total carbon and nitrogen determinations, and micromorphological descriptions. Two vertical sequences at the black deposit of Jabuticabeira II shell mound were studied and preliminary results showed that: (1) depositional attributes are a reliable base for archaeofacies identification in the field, (2) the formation process of this site involved a sequence of anthropic depositional processes, where burned refuse was redeposited over the shell mound following a ritual construction pattern, and (3) the black deposit includes a double palimpsest that refers to provenance and meaning of mound construction material. (C) 2009 Wiley Periodicals, Inc.

ACUTE EFFECTS OF A WARM-UP INCLUDING ACTIVE, PASSIVE, AND DYNAMIC STRETCHING ON VERTICAL JUMP PERFORMANCE

Carvalho, FLP, Carvalho, MCGA, Simao, R, Gomes, TM, Costa, PB, Neto, LB, Carvalho, RLP, and Dantas, EHM. Acute effects of a warm-up including active, passive, and dynamic stretching on vertical jump performance. J Strength Cond Res 26(9): 2447-2452, 2012-The purpose of this study was to examine the acute effects of 3 different stretching methods combined with a warm-up protocol on vertical jump performance. Sixteen young tennis players (14.5 +/- 2.8 years; 175 +/- 5.6 cm; 64.0 +/- 11.1 kg) were randomly assigned to 4 different experimental conditions on 4 successive days. Each session consisted of a general and specific warm-up, with 5 minutes of running followed by 10 jumps, accompanied by one of the subsequent conditions: (a) Control Condition (CC)-5 minutes of passive rest; (b) Passive Stretching Condition (PSC)-5 minutes of passive static stretching; (c) Active Stretching Condition (ASC)-5 minutes of active static stretching; and (d) Dynamic Stretching Condition (DC)-5 minutes of dynamic stretching. After each intervention, the subjects performed 3 squat jumps (SJs) and 3 countermovement jumps (CMJs), which were measured electronically. For the SJ, 1-way repeated measures analysis of variance (CC x PSC x ASC x DC) revealed significant decreases for ASC (28.7 +/- 4.7 cm; p = 0.01) and PSC (28.7 +/- 4.3 cm; p = 0.02) conditions when compared with CC (29.9 +/- 5.0 cm). For CMJs, there were no significant decreases (p > 0.05) when all stretching conditions were compared with the CC. Significant increases in SJ performance were observed when comparing the DC (29.6 +/- 4.9 cm; p = 0.02) with PSC (28.7 +/- 4.3 cm). Significant increases in CMJ performance were observed when comparing the conditions ASC (34.0 +/- 6.0 cm; p = 0.04) and DC (33.7 +/- 5.5 cm; p = 0.03) with PSC (32.6 +/- 5.5 cm). A dynamic stretching intervention appears to be more suitable for use as part of a warm-up in young athletes.

Highly Sensitive Neurotransmitters Analysis at Platinum-Ultramicroelectrodes Arrays

An easy way to determine norepinephrine (NE) in biological fluid using a platinum ultramicroelectrode array (Pt-UMEAs) is described. Issues related to UME electrode surface treatment and characterizations are also addressed. At optimized experimental conditions the dynamic concentration range was 1.0 to 10.0 mu mol?L-1 with a detection limit of 40.5 nmol?L-1. The repeatability of current responses for injections of 5 mu mol?L-1 NE was evaluated to be 4.0?% (n=10). This approach obtained excellent sensitivity, a reliable calibration profile and stable electrochemical response for norepinephrine detection. The content of NE in urine samples without any preconcentration, purification, or pretreatment step, was successfully analyzed by the standard addition method using the Pt-UMEAs.

Cost-effectiveness analysis of universal childhood hepatitis A vaccination in Brazil: Regional analyses according to the endemic context

Objective: To To conduct a cost-effectiveness analysis of a universal childhood hepatitis A vaccination program in Brazil. Methods: An age and time-dependent dynamic model was developed to estimate the incidence of hepatitis A for 24 years. The analysis was run separately according to the pattern of regional endemicity, one for South + Southeast (low endemicity) and one for the North + Northeast + Midwest (intermediate endemicity). The decision analysis model compared universal childhood vaccination with current program of vaccinating high risk individuals. Epidemiologic and cost estimates were based on data from a nationwide seroprevalence survey of viral hepatitis, primary data collection, National Health Information Systems and literature. The analysis was conducted from both the health system and societal perspectives. Costs are expressed in 2008 Brazilian currency (Real). Results: A universal immunization program would have a significant impact on disease epidemiology in all regions, resulting in 64% reduction in the number of cases of icteric hepatitis, 59% reduction in deaths for the disease and a 62% decrease of life years lost, in a national perspective. With a vaccine price of R$16.89 (US$7.23) per dose, vaccination against hepatitis A was a cost-saving strategy in the low and intermediate endemicity regions and in Brazil as a whole from both health system and society perspective. Results were most sensitive to the frequency of icteric hepatitis, ambulatory care and vaccine costs. Conclusions: Universal childhood vaccination program against hepatitis A could be a cost-saving strategy in all regions of Brazil. These results are useful for the Brazilian government for vaccine related decisions and for monitoring population impact if the vaccine is included in the National Immunization Program. (C) 2012 Elsevier Ltd. All rights reserved.

Analysis Methodology for Vortex-Induced Motion (VIM) of a Monocolumn Platform Applying the Hilbert-Huang Transform Method

Vortex-induced motion (VIM) is a highly nonlinear dynamic phenomenon. Usual spectral analysis methods, using the Fourier transform, rely on the hypotheses of linear and stationary dynamics. A method to treat nonstationary signals that emerge from nonlinear systems is denoted Hilbert-Huang transform (HHT) method. The development of an analysis methodology to study the VIM of a monocolumn production, storage, and offloading system using HHT is presented. The purposes of the present methodology are to improve the statistics analysis of VIM. The results showed to be comparable to results obtained from a traditional analysis (mean of the 10% highest peaks) particularly for the motions in the transverse direction, although the difference between the results from the traditional analysis for the motions in the in-line direction showed a difference of around 25%. The results from the HHT analysis are more reliable than the traditional ones, owing to the larger number of points to calculate the statistics characteristics. These results may be used to design risers and mooring lines, as well as to obtain VIM parameters to calibrate numerical predictions. [DOI: 10.1115/1.4003493]

Analysis of energy dissipation in stirred suspension polymerisation reactors using computational fluid dynamics

This work evaluates the spatial distribution of normalised rates of droplet breakage and droplet coalescence in liquidliquid dispersions maintained in agitated tanks at operation conditions normally used to perform suspension polymerisation reactions. Particularly, simulations are performed with multiphase computational fluid dynamics (CFD) models to represent the flow field in liquidliquid styrene suspension polymerisation reactors for the first time. CFD tools are used first to compute the spatial distribution of the turbulent energy dissipation rates (e) inside the reaction vessel; afterwards, normalised rates of droplet breakage and particle coalescence are computed as functions of e. Surprisingly, multiphase simulations showed that the rates of energy dissipation can be very high near the free vortex surfaces, which has been completely neglected in previous works. The obtained results indicate the existence of extremely large energy dissipation gradients inside the vessel, so that particle breakage occurs primarily in very small regions that surround the impeller and the free vortex surface, while particle coalescence takes place in the liquid bulk. As a consequence, particle breakage should be regarded as an independent source term or a boundary phenomenon. Based on the obtained results, it can be very difficult to justify the use of isotropic assumptions to formulate particle population balances in similar systems, even when multiple compartment models are used to describe the fluid dynamic behaviour of the agitated vessel. (C) 2011 Canadian Society for Chemical Engineering

Use of recent geoid models to estimate mean dynamic topography and geostrophic currents in South Atlantic and Brazil Malvinas confluence

The use of geoid models to estimate the Mean Dynamic Topography was stimulated with the launching of the GRACE satellite system, since its models present unprecedented precision and space-time resolution. In the present study, besides the DNSC08 mean sea level model, the following geoid models were used with the objective of computing the MDTs: EGM96, EIGEN-5C and EGM2008. In the method adopted, geostrophic currents for the South Atlantic were computed based on the MDTs. In this study it was found that the degree and order of the geoid models affect the determination of TDM and currents directly. The presence of noise in the MDT requires the use of efficient filtering techniques, such as the filter based on Singular Spectrum Analysis, which presents significant advantages in relation to conventional filters. Geostrophic currents resulting from geoid models were compared with the HYCOM hydrodynamic numerical model. In conclusion, results show that MDTs and respective geostrophic currents calculated with EIGEN-5C and EGM2008 models are similar to the results of the numerical model, especially regarding the main large scale features such as boundary currents and the retroflection at the Brazil-Malvinas Confluence.

Automated analysis of lidocaine and its metabolite in plasma by in-tube solid-phase microextraction coupled with LC-UV for pharmacokinetic study

A sensitive, selective, and reproducible in-tube solid-phase microextraction and liquid chromatographic (in-tube SPME/LC-UV) method for determination of lidocaine and its metabolite monoethylglycinexylidide (MEGX) in human plasma has been developed, validated, and further applied to pharmacokinetic study in pregnant women with gestational diabetes mellitus (GDM) subjected to epidural anesthesia. Important factors in the optimization of in-tube SPME performance are discussed, including the draw/eject sample volume, draw/eject cycle number, draw/eject flow rate, sample pH, and influence of plasma proteins. The limits of quantification of the in-tube SPME/LC method were 50 ng/mL for both metabolite and lidocaine. The interday and intraday precision had coefficients of variation lower than 8%, and accuracy ranged from 95 to 117%. The response of the in-tube SPME/LC method for analytes was linear over a dynamic range from 50 to 5000 ng/mL, with correlation coefficients higher than 0.9976. The developed in-tube SPME/LC method was successfully used to analyze lidocaine and its metabolite in plasma samples from pregnant women with GDM subjected to epidural anesthesia for pharmacokinetic study.

Metabolic oligosaccharide engineering of Plasmodium falciparum intraerythrocytic stages allows direct glycolipid analysis by mass spectrometry

A recent addition to the arsenal of tools for glycome analysis is the use of metabolic labels that allow covalent tagging of glycans with imaging probes. In this work we show that N-azidoglucosamine was successfully incorporated into glycolipidic structures of Plasmodium falciparum intraerythrocytic stages. The ability to tag glycoconjugates selectively with a fluorescent reporter group permits TLC detection of the glycolipids providing a new method to quantify dynamic changes in the glycosylation pattern and facilitating direct mass spectrometry analyses. Presence of glycosylphosphatidylinositol and glycosphingolipid structures was determined in the different extracts. Furthermore, the fluorescent tag was used as internal matrix for the MALDI experiment making even easier the analysis. (C) 2012 Elsevier B.V. All rights reserved.

Effect of enzymatic treatment on the cross-flow microfiltration of acai pulp: Analysis of the fouling and recovery of phytochemicals

This study aimed to investigate the effects of pectinase enzyme treatment of acai pulp on cross-flow microfiltration (CFMF) performance and on phytochemical and functional characteristics of their compounds. Analyses of fouling mechanisms were carried out through resistance in series and blocking in law models. The enzymatic treatment was conducted using Ultrazym(R) AFPL (Novozymes A/S) at 500 mg kg(-1) of acai pulp for 30 min at 35 degrees C. Before microfiltrations, untreated and enzyme-treated acai pulps were previously diluted in distilled water (1:3; w/v). CFMFs were conducted using commercial alpha-alumina (alpha-Al2O3) ceramic membranes (Andritz AG, Austria) of 0.2 mu m and 0.8 mu m pore sizes, and 0.0047 m(2) of filtration area. The microfiltration unit was operated in batch mode for 120 min at 25 degrees C and the fluid-dynamic conditions were transmembrane pressure of Delta P = 100 kPa and cross-flow velocity of 3 m s(-1) in turbulent flow. The highest values of permeate flux and accumulated permeate volume were obtained using enzyme-treated pulp and 0.2 mu m pore size membranes with steady flux values exceeding 100 L h(-1) m(-2). For the 0.8 mu m pore size membrane, the estimated total resistance after the microfiltration of enzyme-treated acai pulp was 21% lower than the untreated pulp, and for the 0.2 mu m pore size membrane, it was 18%. Cake filtration was the dominant mechanism in the early stages of most of the CFMF processes. After approximately 20 min, however, intermediate pore blocking and complete pore blocking contributed to the overall fouling mechanisms. The reduction of the antioxidant capacity of the permeates obtained after microfiltration of the enzyme-treated pulp was higher (p < 0.01) than that obtained using untreated pulp. For total polyphenols, on the contrary, the permeates obtained after microfiltration of the enzyme-treated pulp showed a lower mean reduction (p < 0.01) than those from the untreated pulp. The results show that the enzymatic treatment had a positive effect on the CFMF process of acai pulp. (C) 2012 Elsevier Ltd. All rights reserved.