Método del papel de filtro para la medida de la succión del suelo

The capillary pressure of the soil (i.e., the pressure difference between air and water components in soil voids) is a key variable in the analysis of the hydro-mechanical behavior of unsaturated soils. Therefore a simple and economical laboratory method for the measurement of the capillary pressure of the soil (also known as soil matric suction, the reference being the atmospheric pressure), even if a degree of approximation is involved, is of considerable value. The filter paper method calculates soil suction indirectly by measuring the gravimetric water content of the filter paper at equilibrium that is related to soil suction through a predetermined calibration curve. The advantages of the method are simplicity, economy and reasonable accuracy. It can be used to measure suctions from 10 to 30000 kPa. In this paper, the authors use the contact filter paper method for matric suction measurements of an unsaturated compacted silty sand (formed by the weathering of granite) which has been used as a building material for a road in the north of Portugal. The matric suctions inferred from filter paper measurements depend on the calibration between the water content of the filter paper and suction. Therefore, three calibration curves proposed at the literature (Chandler et al. 1992; ASTM D 5298; and Oliveira & Marinho 2006) for the Whatman 42 filter paper are used to interpret the measured filter paper gravimetric water contents. The results of these tests are compared to other techniques (i.e., tensiometers, and the osmotic technique) used to measure or control the negative pore water pressure in the compacted soil specimens and the results obtained are reasonably accurate.La presión capilar del suelo (es decir, la diferencia de la presión entre el aire y los componentes del agua en vacíos del suelo) es una variable llave en el análisis del comportamiento hidromecánico de suelos no saturados. Un método por lo tanto simple y económico del laboratorio para la medida de la presión capilar del suelo (también conocido como la succión matrica del suelo, la referencia que es la presión atmosférica), mesmo si un grado de aproximación está implicado, es de valor considerable. El método del papel de filtro calcula la succión indirectamente utilizando curvas de calibración. Las ventajas del método son simplicidad, economía y exactitud razonable. El método del papel de filtro se puede utilizar para medir succiones a partir del 10 al 30000 kPa. En este artículo, los autores utilizan el método del papel de filtro para la medida de la succión matric de una arena limosa compactada no saturada (formada por la meteorización del granito) que se ha utilizado como material de construcción para un camino en el norte de Portugal. Las succiones matric deducidas de medidas del papel de filtro dependen de una calibración entre el humedade del papel de filtro y la succión. Por lo tanto, tres curvas de calibración propuestas en la literatura (Chandler et al. 1992; ASTM D 5298; y Oliveira & Marinho 2006) para el papel de filtro de Whatman 42 se utilizan para interpretar lãs humedades gravimétricas medidas del papel de filtro. Los resultados de los ensayos se comparan a otras técnicas (es decir, tensiómetros, y la técnica osmótica) usadas para medir o controlar la presión negativa en lãs muestras compactadas del suelo y los resultados obtenidos sea razonablemente exacto

Efeito da calibração do papel filtro na curva de retenção de um solo arenoso siltoso compactado

The soil suction is a key variable in the analysis of the hydro-mechanical behavior of unsaturated soils. The filter paper method (FPM) calculates soil suction indirectly by measuring the gravimetric water content of the filter paper at equilibrium that is related to soil suction through a predetermined calibration curve. The matric suctions inferred from FPM depend on the calibration between the water content of the filter paper and suction. Therefore, some published calibration curves (Fawcett and Collis-George 1967; Hamblin 1981; Chandler and Gutierrez 1986; Chandler et al. 1992; ASTM D-5298 1992; and Oliveira and Marinho 2006) for the Whatman 42 filter paper are used to interpret the suction measurements of an unsaturated compacted silty sand. Experimental errors induced by using an inadequate calibration curve are discussed. The test results compared to other techniques used to measure or control suctions in the compacted soil specimens are reasonably accurate.A sucção de um solo é uma variável essencial na análise do comportamento de solos não saturados, e é necessário e importante o desenvolvimento de técnicas, diretas e indiretas, de determinação da pressão capilar de solos, que tentam aliar à simplicidade de aplicação, o que se espera ser uma precisão aceitável para os problemas reais do dia a dia da engenharia de solos. O MPF determina a sucção de forma indireta e depende da precisão em que foi determinada a curva de calibração. Várias curvas de calibração para o papel filtro Whatman 42 têm sido propostas na literatura (Fawcett and Collis-George 1967; Hamblin 1981; Chandler and Gutierrez 1986; Chandler et al. 1992; ASTM D-5298 1992; e Oliveira and Marinho 2006). Este artigo discute o uso do MPF para determinar valores de sucção de um solo arenoso siltoso compactado não saturado. Comparam-se os resultados obtidos com outras técnicas utilizadas para medir ou controlar sucções de amostras compactadas do solo arenoso siltoso e conclui-se que o MPF com adequada curva de calibração pode apresentar resultados satisfatórios.Universidade de Coimbra. Faculdade de Ciências e Tecnologia (FCT-UC)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Deep and shallow water effects on developing preschoolers’ aquatic skills

The aim of the study was to assess deep and shallow water teaching methods in swimming lessons for preschool children and identify variations in the basic aquatic skills acquired. The study sample included 32 swimming instructors (16 from deep water programs and 16 from shallow water programs) and 98 preschool children (50 from deep water swimming pool and 48 from shallow water swimming pool). The children were also studied regarding their previous experience in swimming (6, 12 and 18 months or practice). Chi-Square test and Fisher's exact test were used to compare the teaching methodology. A discriminant analysis was conducted with Λ wilk's method to predict under what conditions students are better or worse (aquatic competence). Results suggest that regardless of the non-significant variations found in teaching methods, the water depth can affect aquatic skill acquisition - shallow water lessons seem to impose greater water competence particularly after 6 months of practice. The discriminant function revealed a significant association between groups and all predictors for 6 months of swimming practice (p <0.001). Body position in gliding and leg displacements were the main predictors. For 12 and 18 months of practice, the discriminant function do not revealed any significant association between groups. As a conclusion, it seems that the teaching methodology of aquatic readiness based on deep and shallow water programs for preschoolers is not significantly different. However, shallow water lessons could be preferable for the development of basic aquatic skills

Antioxidant Effects of Quercetin and Catechin Encapsulated into PLGA Nanoparticles

Polymeric nanoparticles (PLGA) have been developed for the encapsulation and controlled release of quercetin and catechin. Nanoparticles were fabricated using a solvent displacement method. Physicochemical properties were measured by light scattering, scanning electron microscopy and ζ-potential, X-ray diffraction, infrared spectroscopy and differential scanning calorimetry. Encapsulation efficiency and in vitro release profiles were obtained from differential pulse voltammetry experiments. Antioxidant properties of free and encapsulated flavonoids were determined by TBARS, fluorescence spectroscopy and standard chelating activity methods. Relatively small (d≈ 400 nm) polymeric nanoparticles were obtained containing quercetin or catechin in a non-crystalline form (EE ≈ 79%) and the main interactions between the polymer and each flavonoid were found to consist of hydrogen bonds. In vitro release profiles were pH-dependant, the more acidic pH, the faster release of each flavonoid from the polymeric nanoparticles. The inhibition of the action of free radicals and chelating properties, were also enhanced when quercetin and catechin were encapsulated within PLGA nanoparticles. The information obtained from this study will facilitate the design and fabrication of polymeric nanoparticles as possible oral delivery systems for encapsulation, protection and controlled release of flavonoids aimed to prevent oxidative stress in human body or food products

Intramuscular Hemangioma in Lip Treated with Sclerotherapy and Surgery

Intramuscular hemangioma is a relatively rare, benign tumor of vascular origin, accounting for less than 1% of all hemangiomas. This paper reports a case of a 48-year-old female patient with intramuscular hemangioma in the upper lip, treated with sclerotherapy and subsequent complementary surgery

Medical error in the portuguese press: when patients are part of the news

Esta investigação aborda a qualidade da produção noticiosa sobre o erro médico, como um fator essencial na construção do conhecimento público sobre o tema, com o objetivo de compreender que características definem tal produção e até que ponto poderão ser explicadas pela periodicidade e orientação editorial dos jornais; que conceito de erro médico é veiculado pela produção noticiosa sobre o tema; e quais são os protagonistas no discurso jornalístico sobre o erro médico. Foram analisadas as edições de três jornais portugueses, de 2008 a 2011, resultando num corpus de 266 (4,2%) artigos, que foram classificados de acordo com as seguintes variáveis: as fontes de informação citadas (o seu estatuto e especialidade, no caso dos médicos); os temas que são tratados; as características de enquadramento da informação publicada (tom, género jornalístico; e a presença e número de fontes de informação). Pela análise de conteúdo quantitativa, apurou-se que esse tema está em crescimento, essencialmente com notícias de tom negativo e fontes de informação habitualmente identificadas. Não há evidência para afirmar que a periodicidade e a orientação editorial expliquem as variações dessas características, a não ser relativamente ao número de fontes citadas. Vigoram as notícias centradas nos resultados dos erros (mortes ou lesões), provocados por "erros de omissão" e por "erros de comissão", envolvendo uma diversidade de protagonistas: são, tal como acontece na informação sobre saúde em geral, fontes oficiais e especializadas do campo da saúde. Destacam-se os médicos e os juristas e é dado relevo aos pacientes.This research addresses the quality of news production on medical error, as an essential factor in building public knowledge on the subject, in order to understand which characteristics define the news production of medical error and to what extent can they be explained by the periodicity and editorial orientation of the newspaper; which concept of medical error is transmitted by the news production on the subject; and who are the main actors in the journalistic discourse about medical error. The editions of three Portuguese newspapers were analyzed, from 2008 to 2011, resulting in a corpus of 266 (4.2%) articles, which were classified according to the following variables: the sources of information quoted (their status and specialty, in the case of doctors); the issues covered; and characteristic framework of the published information (tone, journalistic style, and the presence and number of information sources). Through quantitative content analysis, it was found that this topic is growing, essentially with negative news and information sources usually being identified. There is no evidence to support that periodicity and editorial orientation explain the variations in these characteristics, except for the number of cited sources. News focused on the results of errors (death or injury), caused by "errors of omission" and "commission errors", prevail, involving a variety of actors: they are, such as it happens in health information, in general, official sources and experts in health. Doctors and lawyers stand out, and special attention is given to patients

Salivary flow rate, pH, and concentrations of calcium, phosphate, and sIgA in Brazilian pregnant and non-pregnant women

BACKGROUND: Studies on salivary variables and pregnancy in Latin America are scarce. This study aimed to compare salivary flow rate, pH, and concentrations of calcium, phosphate, and sIgA of unstimulated whole saliva in pregnant and non-pregnant Brazilians. METHODS: Cross-sectional study. Sample was composed by 22 pregnant and 22 non-pregnant women attending the Obstetrics and Gynecology Clinics, São Lucas Hospital, in Porto Alegre city, South region of Brazil. Unstimulated whole saliva was collected to determine salivary flow rate, pH, and biochemical composition. Data were analyzed by Student t test and ANCOVA (two-tailed α = 0.05). RESULTS: No difference was found for salivary flow rates and concentrations of total calcium and phosphate between pregnant and non-pregnant women (p > 0.05). Pregnant women had lower pH (6.7) than non-pregnant women (7.5) (p < 0.001), but higher sIgA level (118.9 mg/L) than the latter (90.1 mg/L) (p = 0.026). CONCLUSION: Some of the tested variables of unstimulated whole saliva were different between pregnant and non-pregnant Brazilians in this sample. Overall, the values of the tested salivary parameters were within the range of international references of normality

Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE

Combined search for the quarks of a sequential fourth generation

Results are presented from a search for a fourth generation of quarks produced singly or in pairs in a data set corresponding to an integrated luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in 2011. A novel strategy has been developed for a combined search for quarks of the up and down type in decay channels with at least one isolated muon or electron. Limits on the mass of the fourth-generation quarks and the relevant Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a simple extension of the standard model with a sequential fourth generation of fermions. The existence of mass-degenerate fourth-generation quarks with masses below 685 GeV is excluded at 95% confidence level for minimal off-diagonal mixing between the third- and the fourth-generation quarks. With a mass difference of 25 GeV between the quark masses, the obtained limit on the masses of the fourth-generation quarks shifts by about +/- 20 GeV. These results significantly reduce the allowed parameter space for a fourth generation of fermions.Comment: Replaced with published version. Added journal reference and DO

Search for anomalous t t-bar production in the highly-boosted all-hadronic final state

A search is presented for a massive particle, generically referred to as a Z', decaying into a t t-bar pair. The search focuses on Z' resonances that are sufficiently massive to produce highly Lorentz-boosted top quarks, which yield collimated decay products that are partially or fully merged into single jets. The analysis uses new methods to analyze jet substructure, providing suppression of the non-top multijet backgrounds. The analysis is based on a data sample of proton-proton collisions at a center-of-mass energy of 7 TeV, corresponding to an integrated luminosity of 5 inverse femtobarns. Upper limits in the range of 1 pb are set on the product of the production cross section and branching fraction for a topcolor Z' modeled for several widths, as well as for a Randall--Sundrum Kaluza--Klein gluon. In addition, the results constrain any enhancement in t t-bar production beyond expectations of the standard model for t t-bar invariant masses larger than 1 TeV.Comment: Submitted to the Journal of High Energy Physics; this version includes a minor typo correction that will be submitted as an erratu