Morphometric properties of alternate bars and water discharge: A laboratory investigation

The formation of alternate bars in straightened river reaches represents a fundamental process of river morphodynamics that has received great attention in the last decades. It is well-established that migrating alternate bars arise from an autogenic instability mechanism occurring when the channel width-to-depth ratio is sufficiently large. While several empirical and theoretical relations are available for predicting how bar height and length depend on the key dimensionless parameters, there is a lack of direct, quantitative information about the dependence of bar properties on flow discharge. We performed a series of experiments in a long, mobile-bed flume with fixed and straight banks at different discharges. The self-formed bed topography was surveyed, different metrics were analyzed to obtain quantitative information about bar height and shape, and results were interpreted in the light of existing theoretical models. The analysis reveals that the shape of alternate bars highly depends on their formative discharge, with remarkable variations in the harmonic composition and a strong decreasing trend of the skewness of the bed elevation. Similarly, the height of alternate bars clearly decreases with the water discharge, in quantitative agreement with theoretical predictions. However, the disappearance of bars when discharge exceeds a critical threshold is not as sharp as expected due to the formation of so-called "diagonal bars". This work provides basic information for modeling and interpreting short-term morphological variations during individual flood events and long-term trajectories due to alterations of the hydrological regime

About the kinetics and mechanism of the reactions of 4-(2-pyridylaza) resorcinol, with Zn2+, Cu2+, and Zn2++Cu2+ equimolar mixtures, in aqueous solutions

The kinetics and mechanism of the reactions between 4-(2-pyridylazo)-resorcinol and Zn-2+, Cu2+ and Zn2++Cu2+ equimolar mixtures were studied. The reactions were performed in aqueous solution (pH = 8.5, borate buffer) and monitored spectrophotometrically at 500 nm using stopped-flow technique. Spectral and kinetic data indicate that the Zn2++Cu2+ equimolar mixture behaves as an unique species and it can be attributed to the interactions of Zn2+ and of Cu2+ with water molecules in the aqueous solution. A mechanism is proposed and the rate constants are calculated.281556

A Green Method for Determination of Acid Number of Biodiesel

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)A simple green method for the determination of the acid number of biodiesel is described. The sample is dissolved in a 1:1 v/v ethanol: water mixture, avoiding the use of the usual toluene: isopropanol:water mixture (1:0.95:0.5 v/v/v). The titration is performed with a 0.02 mol L(-1) NaOH solution in water. The method was compared with that of ABNT NBR 14448, which is similar to ASTM D 664 and to EN 14104. A statistical comparison using the student's t test and the Snedecor F test showed that the proposed method offers equivalent results to ABNT NBR 14448, with better precision.22610731081Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Assessment of the Triage System in a Pediatric Emergency Department. A pilot study on critical code

Introduction. In Italy, triage involves assigning a priority color code to patients arriving at the hospital Emergency Department: red (very critical), yellow (moderately critical), green (not very critical), and white (not critical). Methods. This study was aimed at assessing the triage system in the Emergency Department of ?Giannina Gaslini? Children? s Hospital in Genoa, Italy. The authors examined 130 triage forms assigning a yellow code in 2003, in order to determine whether they had been correctly filled in with regard to the detection of vital parameters, identification of main symptoms and color code assignment. Results. Results showed that vital signs were recorded in 94% of patients, main symptoms were identified in 97%, and a yel- low code was assigned according to hospital guidelines in 84%. The percentage of underestimation (3.2%) was higher than that reported in the literature (2%). Conclusions. The study shows the need to improve compliance with the guidelines and to evaluate green and white codes

Quantitative reflectance spot test for the determination of acetylsalicylic acid in pharmaceutical preparations

This paper describes a quantitative reflectance spot test procedure for the determination of acetylsalicylic acid (ASA) in pharmaceutical preparations. The method is based on the reaction of salicylic acid, obtained from the hydrolysis of ASA, with Fe(III) forming a deep blue-violet compound. Medicines containing ASA can be easily analyzed by the proposed method as it is not necessary to do any separation. The final mixture is placed on a sheet of filter paper, and the reflectance is directly measured. Nine commercial medicines containing acetylsalicylic acid were analyzed with the proposed method. The mean RSD was 0.9%. Results were compared with those obtained with the United States Pharmacopoeia recommended procedure (RSD 0.6%). The quantitative detection limit is 0.6 mg ASA in the working solution. For a degree of freedom n = 4 (n = n1+ n2 - 2) and a confidence coefficient a = 0.05 all the results agree under the tabulated t-Student test value (2.78).Este trabalho descreve um método para a determinação quantitativa de ácido acetilsalicílico (ASA) utilizando procedimento spot test e reflectância difusa. O método é baseado na formação do complexo de cor roxa intensa entre o ácido salicílico, obtido a partir da hidrólise alcalina do ASA, e íons Fe(III). O procedimento proposto permite a análise de medicamentos contendo ASA de forma fácil e simples, uma vez que não é necessário fazer separações. A reflectância da mistura final, colocada sobre um disco de papel de filtro, é medida diretamente. Foram analisados nove medicamentos comerciais contendo ASA cujos resultados apresentaram um desvio padrão relativo médio de 0,9%. O limite para a determinação quantitativa é de 0,6 mg de ASA na solução de trabalho. As análises feitas com o método proposto foram comparadas com outras análises, das mesmas amostras, segundo o procedimento recomendado pela United States Pharmacopoeia, onde se observou um desvio padrão relativo de 0,6%. Compararam-se os dois métodos utilizando-se o teste t de Student. Para um grau de liberdade n = 4 (n = n1 + n2 - 2) e um limite de confiança a = 0.05, onde t = 2,78, todos os resultados foram concordantes.327330Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Perspectives of stack and environmental monitoring in the surroundings of a waste-to-energy plant

Waste-to-Energy (WtE) processes respond both to the emerging need for reducing the flow of waste into the environment and, at the same time, to the increasing demand for energy. Despite, these evident advantages, WtE plants still present some critical issues regarding the emissions of heavy metals into the atmosphere, which are regulated by the environmental legislations but, concerning the European Union, are regarded as groups of metals with no consideration of the different carcinogenic potential of each metal. In addition, there are uncertainties on the estimation of the balance of carbon dioxide, which depends on several factors like transportation, type of incoming waste, processes in use and secondary emissions. Despite great improvements in air pollution control from this sector, persistent organic pollutants are still emitted by WtE plants. Therefore, the implementation of adequate environmental monitoring (EM) plans is essential to monitor the impact of WtE plants in their surroundings, especially in the presence of the population, fields and pastures. In view of these considerations, this paper aims to provide guidance on basic and novel approaches that are necessary for a comprehensive monitoring of the impacts of a new WtE plant in terms of air quality and public health. A case study regarding the EM plan proposed for a new WtE plant will also be reported as an example

Spot-test identification and rapid quantitative sequential analysis of dipyrone

A qualitative spot-test and tandem quantitative analysis of dipyrone in the bulk drug and in pharmaceutical preparations is proposed. The formation of a reddish-violet color indicates a positive result. In sequence a quantitative procedure can be performed in the same flask. The quantitative results obtained were statistically compared with those obtained with the method indicated by the Brazilian Pharmacopoeia, using the Student's t and the F tests. Considering the concentration in a 100 µL aliquot, the qualitative visual limit of detection is about 5×10-6 g; instrumental LOD ≅ 1.4×10-4 mol L-1 ; LOQ ≅ 4.5×10-4 mol L-1.Um método spot-test qualitativo e seqüencialmente quantitativo é proposto para análise de dipirona em fármaco puro e em preparações farmacêuticas. A formação de coloração vermelho-violeta indica um resultado qualitativo positivo. Na seqüência, um procedimento quantitativo pode ser realizado no mesmo frasco. Os resultados quantitativos obtidos foram comparados estatisticamente com os resultados obtidos pelo método indicado pela Farmacopéia Brasileira, utilizando o teste t de Student e o teste F. Considerando a concentração em uma alíquota de 100 µL, o limite qualitativo visual de detecção foi de cerca 5×10-6 g; instrumentalmente o limite de detecção foi de LOD ≅ 1.4×10-4 mol L-1 e o limite de quantificação de LOQ ≅ 4.5×10-4 mol L-1.4146Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

One Dimensional Polymeric Organic Photonic Crystals for DFB Lasers

We present a very simple method to realize a one-dimensional photonic crystal (1D PC), consisting of a dye-doped polymeric multilayer. Due to the high photonic density of states at the edges of the photonic band-gap (PBG), a surface emitting distributed feedback (DFB) laser is obtained with this structure. Furthermore, the incidence angle dependence of the PBG of the polymeric multilayer is reported

Influence of water and ultraviolet irradiation on the induction period of the oxidation of biodiesel

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Biodiesel degrades due to oxidative processes, causing a decrease in its quality. In the present work, it has been clearly shown that the incidence of ultraviolet radiation on biodiesels obtained from soy, canola, linseed and microalgae oils initiate oxidative processes which lead to the decrease in the induction period (IP) of the fuel. The influence of the residual water content of the same biodiesels on the oxidation process was also investigated with and without the incidence of ultraviolet radiation. Between 190 and 850 ppm of water in the biodiesel and without UV irradiation, no significant change in the IP values was observed under the experimental conditions.Biodiesel degrades due to oxidative processes, causing a decrease in its quality. In the present work, it has been clearly shown that the incidence of ultraviolet radiation on biodiesels obtained from soy, canola, linseed and microalgae oils initiate oxid284676680FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)sem informaçãosem informaçãoThe authors are grateful to CNPq for financial support and to Dr. Fabio Batista (EXTRAE-UNICAMP) who graciously provided the microalgae oi