294 research outputs found

    Thermal suspectability analysis of the reuse of fly ash from cellulose industry as contribution filler in bituminous mixtures

    Get PDF
    The increased population has accelerated pavement deterioration of and boosted production of residues, generating a constant environmental problem. One of the main problems of pavements is a failure to develop union between bituminous mastic ligand and aggregate. The following study evaluates the use of ash from cellulose incineration as a contribution filler to improve thermal susceptibility of pavements in different climatic zones. The applied methodology for dosage was based on volumetric criteria and state curves. The obtained results showed that reusing this residue in determined conditions (Cv/Cs???1) offers lower wear loss to 35% of temperatures between ?10 and 60?°C, due to the Cv/Cs?=?0.75 ratio that maximizes the cohesive properties of the mixture. Therefore, we showed that this type of industry residue can be reused without complication in zones of certain climatic criteria and that it provides improved properties to the asphalt mix compared to conventional mixes

    Influence of free fatty acid content and degree of fat saturation in laying hen diets on egg quality, yolk fatty acid profile, and cholesterol content

    Full text link
    The aim of the present study was to evaluate the effect of dietary free fatty acid (FFA) content and the degree of saturation on egg quality, yolk fatty acid (FA) profile, and yolk cholesterol content. For a 15-wk period, a total of 144 laying hens (19-wk-old) were randomly assigned to 8 treatments arranged in a 2 × 4 factorial design, with 2 sources of crude oil (soybean oil and palm oil) and 4 levels of FFA (10, 20, 30, and 45%). The dietary treatments were achieved by progressively substituting the original oils with equivalent amounts of their corresponding acid oils (soybean acid oil and palm fatty acid distillate, respectively). No differences in ADFI or egg mass were found. However, dietary FFA reduced egg production (linear, P 0.05). The saturation degree had a significant effect on all the analyzed yolk FA (P < 0.001) except for arachidonic acid (C20:4 n-6), whereas increasing the FFA content did not affect to a great extent. These results show that varying dietary FFA level did not affect egg quality and yolk composition as much as the dietary fat source did, supporting the use of acid oils and fatty acid distillates as fat ingredients for feed

    Nonequilibrium wetting

    Full text link
    When a nonequilibrium growing interface in the presence of a wall is considered a nonequilibrium wetting transition may take place. This transition can be studied trough Langevin equations or discrete growth models. In the first case, the Kardar-Parisi-Zhang equation, which defines a very robust universality class for nonequilibrium moving interfaces, with a soft-wall potential is considered. While in the second, microscopic models, in the corresponding universality class, with evaporation and deposition of particles in the presence of hard-wall are studied. Equilibrium wetting is related to a particular case of the problem, it corresponds to the Edwards-Wilkinson equation with a potential in the continuum approach or to the fulfillment of detailed balance in the microscopic models. In this review we present the analytical and numerical methods used to investigate the problem and the very rich behavior that is observed with them.Comment: Review, 36 pages, 16 figure

    Hadronic Charmed Meson Decays Involving Tensor Mesons

    Full text link
    Charmed meson decays into a pseudoscalar meson P and a tensor meson T are studied. The charm to tensor meson transition form factors are evaluated in the Isgur-Scora-Grinstein-Wise (ISGW) quark model. It is shown that the Cabibbo-allowed decay Ds+f2(1270)π+D_s^+\to f_2(1270)\pi^+ is dominated by the W-annihilation contribution and has the largest branching ratio in DTPD\to TP decays. We argue that the Cabibbo-suppressed mode D+f2(1270)π+D^+\to f_2(1270)\pi^+ should be suppressed by one order of magnitude relative to Ds+f2(1270)π+D_s^+\to f_2(1270)\pi^+. When the finite width effect of the tensor resonances is taken into account, the decay rate of DTPD\to TP is generally enhanced by a factor of 232\sim 3. Except for Ds+f2(1270)π+D_s^+\to f_2(1270)\pi^+, the predicted branching ratios of DTPD\to TP decays are in general too small by one to two orders of magnitude compared to experiment. However, it is very unlikely that the DTD\to T transition form factors can be enhanced by a factor of 353\sim 5 within the ISGW quark model to account for the discrepancy between theory and experiment. As many of the current data are still preliminary and lack sufficient statistic significance, more accurate measurements are needed to pin down the issue.Comment: 11 page

    Role of toxin activation on binding and pore formation activity of the Bacillus thuringiensis Cry3 toxins in membranes of Leptinotarsa decemlineata (Say)

    Get PDF
    AbstractBinding and pore formation constitute key steps in the mode of action of Bacillus thuringiensis δ-endotoxins.In this work, we present a comparative analysis of toxin-binding capacities of proteolytically processed Cry3A, Cry3B and Cry3C toxins to brush border membranes (BBMV) of the Colorado potato beetle Leptinotarsa decemlineata (CPB), a major potato coleopteran-insect pest. Competition experiments showed that the three Cry3 proteolytically activated toxins share a common binding site. Also heterologous competition experiments showed that Cry3Aa and Cry3Ca toxins have an extra binding site that is not shared with Cry3Ba toxin. The pore formation activity of the three different Cry3 toxins is analysed. High pore-formation activities were observed in Cry3 toxins obtained by proteolytical activation with CPB BBMV in contrast to toxins activated with either trypsin or chymotrypsin proteases. The pore-formation activity correlated with the formation of soluble oligomeric structures. Our data support that, similarly to the Cry1A toxins, the Cry3 oligomer is formed after receptor binding and before membrane insertion, forming a pre-pore structure that is insertion-competent

    Nonleptonic two-body charmless B decays involving a tensor meson in ISGW2 model

    Full text link
    Nonleptonic charmless B decays into a pseudoscalar (P) or a vector (V) meson accompanying a tensor (T) meson are re-analyzed. We scrutinize the hadronic uncertainties and ambiguities of the form factors which appear in the literature. The Isgur-Scora-Grinstein-Wise updated model (ISGW2) is adopted to evaluate the relevant hadronic matrix elements. We calculate the branching ratios and CP asymmetries for various BP(V)TB\to P(V)T decay processes. With the ISGW2 model, the branching ratios are enhanced by about an order of magnitude compared to the previous estimates. We show that the ratios \calB(B\to VT)/\calB(B\to PT) for some strangeness-changing processes are very sensitive to the CKM angle γ\gamma (ϕ3\phi_3).Comment: 23 pages, REVTEX; minor clarifications included; to appear in Phys. Rev.

    Reduction in the use of mineral aggregate by recycling cellulose ashes to decrease the aging of hot asphalt mixtures

    Get PDF
    The rapid development that our society is experiencing effects road management, therefore developing economical and efficient solutions, as well as extending road service life is indispensable. Aging is a problem associated to the majority of failures at the pavement surface layer (cracks, fissures, fatigue), including those produced by traffic solicitations. Diverse studies indicate that alterations to mixtures due to age can be decreased by incorporating a filler or mineral filler. Therefore, the present study incorporates cellulose ashes at different Cv/Cs concentrations as contribution filler in bituminous mastic, analysing its influence on aging resistance using the Cantabro wear test. The results indicated that using cellulose ash as contribution filler allows promising results to be obtained in regards to aging resistance of asphalt mixtures, if they are incorporated in concentrations close to or equal to the critical concentration, with an increase in aging resistance from 45.3 to 48.6% depending on the type of bitumen used. Therefore, incorporating them into the design of asphalt mixtures could be an efficient and economical solution to the current problems of early cracking and pavements with a service life lower than the estimated, although a more thorough analysis of its behaviour in other tests and service conditions is required in bituminous mixtures.The presented results are part of the FONDECYT Initiation 2013 into Research project No. 11130309, funded by CONICYTChile. The authors also would like to thank ARAUCO, Bitumix S.A. and Química Latinoamericana for the material donations

    Recent sediments dating using short-lived radionuclides

    Full text link
    [ES] Se presentan las características principales del método de datación de sedimentos recientes mediante el radioisótopo natural 210Pb y su validación utilizando radionucleidos artificiales tales como 137Cs y 239,240Pu. Se hace una revisión de los principios generales de esta metodología, se aportan recomendaciones prácticas para la recogida de testigos sedimentarios en el campo y su posterior procesamiento en el laboratorio, se describen diferentes técnicas analíticas utilizadas en la determinación de sus concentraciones y se explican brevemente varios modelos para la interpretación de los perfiles obtenidos. Por último, se incluyen ejemplos prácticos de su aplicación en secuencias sedimentarias procedentes de distintos ambientes marinos (estuario, bahía y plataforma continental) en el norte de la Península Ibérica.[EN] The main characteristics of the dating method of recent sediments using the natural radioisotope 210Pb and its validation with artificial radionuclides such as 137Cs and 239,240Pu are presented. A review of the general principles of this methodology is made, practical recommendations for the collection of sedimentary cores in the field and their subsequent processing in the laboratory are provided, several analytical techniques used to measure their concentrations are described and several models for the interpretation of the profiles are briefly explained. Finally, practical examples of its application in sedimentary sequences from different marine environments (estuary, bay and continental shelf) in the northern Iberian Peninsula are also included.Este artículo se ha inspirado en el manual de referencia publicado por Sanchez-Cabeza, J.A., Díaz-Asencio, M., Ruiz-Fernández, A.C., eds. (2012). Radiocronología de sedimentos costeros utilizando 210Pb: Modelos, Validación y Aplicaciones. Organismo Internacional de Energía Atómica, Viena, 105 pp., donde se profundizan diferentes aspectos tratados aquí. Trabajo financiado por los proyectos RTI2018-095678-B-C21, MCIU/AEI/FEDER, UE (MINECO) e IT976-16 (EJ/GV). Dos revisoras/es anónimas/os mejoraron el manuscrito original con sus comentarios y sugerencias. Contribución nº 56 de la Unidad de Investigación Geo-Q Zentroa (Laboratorio Joaquín Gómez de Llarena).Cearreta, A.; Gómez-Arozamena, J.; Irabien, M.; Ruiz-Fernández, A.; Sanchez-Cabeza, J.; Ortiz Moragón, J.; Sáez-Muñoz, M. (2022). Datación de sedimentos recientes utilizando radionucleidos de vida corta. Cuaternario y Geomorfología. 36(3-4):87-104. https://doi.org/10.17735/cyg.v36i3-4.9350487104363-

    Validation of miR-1228-3p as Housekeeping for MicroRNA Analysis in Liquid Biopsies from Colorectal Cancer Patients

    Get PDF
    BACKGROUND: Circulating microRNA (miRNA) analysis is a growing research field. However, it usually requires an endogenous control or housekeeping (HK) in order to normalize expression of specific miRNAs throughout different samples. Unfortunately, no adequate HK for circulating miRNA analysis is still known in the colorectal cancer (CRC) context whereas several have been suggested. Hence, our aims were to validate the previously suggested miR-1228-3p as HK for CRC studies, to compare its suitability with the widely used miR-16-5p, and to evaluate the influence of hemolysis on both miRNAs. METHODS: We analyzed by quantitative reverse-transcription polymerase chain reaction (qRT-PCR) the expression of miR-1228-3p, miR-16-5p and the spike-in cel-miR-39 in a set of 297 plasmas (92 CRC, 101 advanced adenomas -AA-, and 100 controls) and 213 serum samples (59 CRC, 74 AA and 80 controls). We also analyzed both miRNAs depending on the hemolysis degree in 7 plasmas and 31 serums. RESULTS: Levels of miR-1228-3p and miR-16-5p did not show significant differences between groups although miR-16-5p exhibited more variability in plasma and serum samples. Importantly, the combination of cel-miR-39 and miR-1228-3p was the most stable one. Moreover, we observed that miR-16-5p was significantly influenced by hemolysis in contrast with miR-1228-3p that exhibited no correlation with this confounding factor in both biofluids. CONCLUSION: MiR-1228-3p has been validated as an adequate endogenous control for circulating miRNA analysis in CRC and AA liquid biopsies

    Geometric Approach to Pontryagin's Maximum Principle

    Get PDF
    Since the second half of the 20th century, Pontryagin's Maximum Principle has been widely discussed and used as a method to solve optimal control problems in medicine, robotics, finance, engineering, astronomy. Here, we focus on the proof and on the understanding of this Principle, using as much geometric ideas and geometric tools as possible. This approach provides a better and clearer understanding of the Principle and, in particular, of the role of the abnormal extremals. These extremals are interesting because they do not depend on the cost function, but only on the control system. Moreover, they were discarded as solutions until the nineties, when examples of strict abnormal optimal curves were found. In order to give a detailed exposition of the proof, the paper is mostly self\textendash{}contained, which forces us to consider different areas in mathematics such as algebra, analysis, geometry.Comment: Final version. Minors changes have been made. 56 page
    corecore