Um objeto de aprendizagem para o ensino de Química Geral

Os calouros usualmente encontram dificuldades na disciplina de Química Geral. O objetivo desta proposta é o de contribuir para a melhoria da aprendizagem deles através do desenvolvimento de um hipertexto, que abrange oconteúdo discutido na disciplina oferecida no Instituto de Química da UFRGS para os alunos dos cursos de Química, Engenharia Química e Engenharia de Materiais.Cada assunto é apresentado através de diferentes abordagens: texto escrito e ilustrado, exercícios resolvidos e discutidos, problemas de diferentes graus de complexidade, além de informações complementares onde a relação e a integração com outros assuntos e também com a vida cotidiana podem ser feitas. Os alunos que se dispuseram a utilizar o material o avaliaram positivamente, embora muitos deles ainda apresentem resistência à utilização de métodos que usam estratégias de estudo mediadas por computador, sem a orientação de um professor

Reporting an experience : recovering and recording residues of teaching laboratories of Chemical Institute of the Federal University of Rio Grande do Sul.

An experience aiming to promote a residue interchange and recovery between the teaching laboratories of the Chemistry Institute of this University is described. At the present, several residues interchange have already appeared as advantageous. To make the work easier, a software has been developed in order to keep a record of all the residues generated by the teaching laboratories. Standard labels have been developed for the residues in order to organize them. The software and the label design are described

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

The performance of GARCH option pricing models : An empirical study on Swedish OMXS30 call options

The purpose of this thesis is to examine the properties for different specifications of the HestonNandi GARCH option pricing model and the pricing performance on european Swedish OMXS30 call options. The sample consists of a total of 2467 options (both in-sample and out-of-sample) for 2011 and 2012, which are priced with three specifications of the HestonNandi-GARCH model and then compared to the pricing performance of the BlackScholes model. The examination shows that the BlackScholes model performs better out-of-sample then the specifications of the HestonNandi GARCH model. All models pricing errors show significant relationship to moneyness and the term structure of the interest rate. We also confirm the findings of Heston and Nandi (2000) who states that their model is especially sensitive to the volatility of volatility and the skewness parameter.

La correspondencia de Valencia : diario de noticias : eco imparcial de la opinión y de la prensa: Año XLVI Número 18941 - 1923 Marzo 03

Copia digital. Madrid : Ministerio de Cultura. Subdirección General de Coordinación Bibliotecaria, 200

Verificação de inibição da corrosão da liga Fe64Ni36 em perclorato de pH 6,0 por silicato

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Verificação de inibição da corrosão da liga Fe64Ni36 em perclorato de pH 6,0 por silicato

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An attempt of experimental separation of the potentiodynamic anodic peaks of iron in alkaline solutions and application of the ohmic model for passive film growth

The composition of the oxide film formed on iron during potentiodynamic experiments as well as the formation mechanism are still under much discussion. In the present study an experimental separation of anodic peaks was performed from the first voltammetric scan obtained for iron in borax 0.1 mol l−1 and NaOH 0.01 mol l−1+sodium silicate (500 ppm SiO2). A charge density balance has also been performed in order to discuss mechanisms already proposed in the literature. Among several models proposed for the kinetics of passive film growth, the ohmic model is recent and was applied to the study of the second potentiodynamic anodic peak obtained for iron in borate 0.1 mol l−1 and to the third potentiodynamic anodic peak obtained for iron in NaOH 0.01 mol l−1+sodium silicate (500 ppm SiO2). The results showed that the model is suitable to explain the electrochemical behaviour of iron under these conditions

Influência do pH na ação inibidora do silicato sobre a corrosão do ferro e do alumínio

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Influência do pH na ação inibidora do silicato sobre a corrosão do ferro e do alumínio

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