1,055 research outputs found
Leto, Maria F.
No full textCentro Asturiano membership record of Maria F. Leto; Socio Number: 794.https://digitalcommons.usf.edu/asturiano_membership/3959/thumbnail.jp
Estudo do comportamento do concreto asfáltico modificado pelo polímero EVA no módulo complexo e na fadiga
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia Civil.O objetivo desta pesquisa é estudar o comportamento do concreto asfáltico alterando as características originais por meio da sua modificação pelo polímero EVA (etileno acetato de vinila). Ensaios laboratoriais da metodologia francesa são realizados para formular um concreto asfáltico que seja capaz de resistir ao tráfego de maneira satisfatória, garantindo a qualidade do material ao longo da vida útil na estrutura de pavimento em que será aplicado. Nesse estudo foram utilizados dois tipos de ligantes asfálticos, sendo um ligante 50/70 convencional e um ligante 50/70 modificado com o copolímero EVA. Foram realizados ensaios de caracterização dos materiais, além dos ensaios Marshall, Duriez, Deformação Permanente, compreendendo ainda os ensaios fundamentais de Módulo Complexo e de Fadiga. Com a análise dos resultados desses ensaios pode-se concluir que o polímero EVA melhorou as características do concreto asfáltico. A eficácia do polímero foi constatado nos ensaios de Duriez (menor perda de resistência devido à ação da água), no ensaio de Deformação Permanente (maior resistência às solicitações de tráfego) e no ensaio de Fadiga (deformação admissível maior que o concreto asfáltico convencional). É feito um dimensionamento simulado onde demonstra que o uso do ligante modificado pelo polímero EVA faz com que diminua em dois centímetros a camada asfáltica. Em se tratando de obras de pavimentação, que se estendem por quilômetros, essa pequena espessura faz com que reduza os custos de uma obra rodoviária e aumente a vida útil do pavimento, visto que o concreto asfáltico modificado possui uma resistência maior à deformação permanente e à fadiga do que os concretos asfálticos convencionais.The objective of this research is to study the behavior of asphalt concrete by altering its original characteristics through its modification by the EVA polymer (ethylene vinyl acetate). Laboratory tests applying the French methodology have been performed to produce an asphalt concrete, which is designed to resist traffic loads in a satisfactory manner, ensuring the quality of the material throughout the life of the flooring structure that will be applied. In this case, we have used two types of asphalt binders: a conventional 50/70 binder and a 50/70 binder with a modified EVA copolymer. Tests have been performed to characterise the material in addition to the Marshall test, Duriez test, Permanent Deformation test, comprising also the key tests such as Module Complex and Fatigue. Through the tests result analysis we concluded that the EVA polymer provided an improvement on the asphalt concrete characteristics. The polymer effectiveness was identified Duriez test (resistance loss due the water#s action), Permanent Deformation test (high resistance on traffic requests) and Fatigue test (admissible deformation higher than conventional asphaltic concrete). A structure simulation was carried out in which demonstrates the use of asphalt binder with a modified EVA copolymer resulting in two less centimeters of asphalt layer. In the case of pavement, which are extents, this small thickness reduced road work expenditures and increased the pavement life cycle. We concluded that the modified asphalt concrete has a higher resistance than conventional asphalt concrete in relation to permanent deformation and fatigue
Il commento di Pomponio Leto all'Eneide di Virgilio
No full textAnalisi di alcune esegesi virgiliane proposte da Pomponio Leto nel suo commento inedito
C/F ratio in body weight-matched OLETF and LETO rats.
No full textC/F ratio in body weight-matched OLETF and LETO rats.</p
Analytical evaluation of the Tosoh HLC-723 G7 automated HPLC analyzer for hemoglobin A2 and F determination
No full textObjectives: The analytical performance of a new automated HPLC system (Tosoh HLV-723 G7) for Hb A2 and Hb F quantification in blood was studied. Design and methods: Hb A2 and Hb F measurements were studied for imprecision, linearity, carry-over, interferences and sample concentration effect. Method comparison study was performed with the Bio-Rad Variant II HPLC system. Hb F results were also compared with those obtained by the alkaline denaturation test. The detection of some common Hb variants was also studied. Results: Hb A2 within-run and between-run CVs were found between 0.8–2.2 % and 2.9–7.2 %, respectively, while CVs for Hb F were up to 10.0 % in normal and between 1.9–5.3 % at more clinically relevant Hb F concentrations (N1.5 %). Comparison study with Bio-Rad Variant II for Hb A2 determination showed good correlation but highlighted calibration differences. The following results were obtained in two different laboratories: y = 1.163x 0.52, r = 0.9918, n = 144 (Lab A); y = 1.060x 0.40, r = 0.9920, n = 93 (Lab B). With regard to the determination of Hb F, the measurements performed by the tested method was found to correlate well with the alkaline denaturation test ( y = 1.0138x 0.36, r = 0.9842, n = 20) and with the Variant II HPLC system ( y = 0.812x + 0.52, r = 0.9835, n = 110). An excellent linearity (r = 0.999) was found for both Hb A2 and Hb F in the range 0.8–19 %. Hb S, Hb C and Hb D can be presumptively identified by the assigned retention time windows. Conclusion: The new analyzer Tosoh HLV-723 G7 was found to be a reliable method for Hb A2 and Hb F quantification and for the presumptive identification of some common Hb variants
De lingua latina
No full text[84] h. ; 4o. -- Edición al cuidado de Pomponio Leto. -- Sign.: [*10, a-c10, d-e6, f-g10, h12]
Intuizioni esegetiche di Pomponio Leto nel suo commento a georgiche e all'Eneide
No full textIl commento virgiliano inedito di Pomponio Leto (sec. XV) anticipa numerosi spunti esegetici emersi nei secoli successivi. L'articolo interessa in particolare le esegesi relative al codice Mediceo e alla sua interpretazione
Lifespan of neurons is uncoupled from organismal lifespan.
No full textNeurons in mammals do not undergo replicative aging, and, in absence of pathologic conditions, their lifespan is limited only by the maximum lifespan of the organism. Whether neuronal lifespan is determined by the strain-specific lifetime or can be extended beyond this limit is unknown. Here, we transplanted embryonic mouse cerebellar precursors into the developing brain of the longer-living Wistar rats. The donor cells integrated into the rat cerebellum developing into mature neurons while retaining mouse-specific morphometric traits. In their new environment, the grafted mouse neurons did not die at or before the maximum lifespan of their strain of origin but survived as long as 36 mo, doubling the average lifespan of the donor mice. Thus, the lifespan of neurons is not limited by the maximum lifespan of the donor organism, but continues when transplanted in a longer-living host
Energy transformations in primary school: outcomes from a research based experimentation
No full textEnergy is a topic which appears many times in Italian curricula. The school puts a strong socioeconomical
attention to protection of the environment and experts often are invited to make speeches
on this topic in primary classroom. This type of approaches are those of newspapers and the common
language. A vast literature has highlighted those learning difficulties linked to common sense way of
looking to energy concepts and its processing (Millar R. 2005, Heron P., Michelini M. and Stefanel A.,
2008). Didactic proposals on energy topic of different approaches (Kaper, W. and Goedhart, M. 2002;
Hobson A. 2004) offer to the teacher the opportunity to treat this topic revisiting concepts in such a
way as to help children overcome the conceptual knots (Driver R. and Warrington L. 1985; Heron et.
al. 2008) that the daily context poses. In a research based experimentation the HMS (HMS - Heron et.
al. 2008) approach is adopted to build the concepts of energy by means of experimental exploration,
and to complete a teaching of energy based on the content offered by text book: energy form, energy
production. The experimental class includes twenty three 8-year-old children of a school of Perugia, Italy.
HMS educational path has been applied using Inquiry based learning strategy and monitoring learning by
means of boarding diary, in(I)-out(O)- and post(P)-tests (IOP tests). Some interesting elements emerge,
especially concerning transformation concept, which appears in different key-situations explored
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