5,407 research outputs found

    Correction of diffraction effects in confocal raman microspectroscopy

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    A mathematical approach developed to correct depth profiles of wet-chemically modified polymer films obtained by confocal Raman microscopy is presented which takes into account scattered contributions originated from a diffraction-limited laser focal volume. It is demonstrated that the problem can be described using a linear Fredholm integral equation of the first kind which correlates apparent and true Raman intensities with the depth resolution curve of the instrument. The calculations of the corrected depth profiles show that considerable differences between apparent and corrected depth profiles exist at the surface, especially when profiles with strong concentration gradients are dealt with or an instrument with poor depth resolution is used. Degrees of modification at the surface obtained by calculation of the corrected depth profiles are compared with those measured by FTIR-ATR and show an excellent concordance.</p

    The boundary field theory induced by the Chern-Simons theory

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    The Chern-Simons theory defined on a 3-dimensional manifold with boundary is written as a two-dimensional field theory defined only on the boundary of the three-manifold. The resulting theory is, essentially, the pullback to the boundary of a symplectic structure defined on the space of auxiliary fields in terms of which the connection one-form of the Chern-Simons theory is expressed when solving the condition of vanishing curvature. The counting of the physical degrees of freedom living in the boundary associated to the model is performed using Dirac's canonical analysis for the particular case of the gauge group SU(2). The result is that the specific model has one physical local degree of freedom. Moreover, the role of the boundary conditions on the original Chern- Simons theory is displayed and clarified in an example, which shows how the gauge content as well as the structure of the constraints of the induced boundary theory is affected.Comment: 10 page

    Blade loss transient dynamics analysis. Volume 3: User's manual for TETRA program

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    The users manual for TETRA contains program logic, flow charts, error messages, input sheets, modeling instructions, option descriptions, input variable descriptions, and demonstration problems. The process of obtaining a NASTRAN 17.5 generated modal input file for TETRA is also described with a worked sample

    Screening of heterogeneous surfaces: charge renormalization of Janus particles

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    Nonlinear ionic screening theory for heterogeneously charged spheres is developed in terms of a mode-decomposition of the surface charge. A far-field analysis of the resulting electrostatic potential leads to a natural generalization of charge renormalization from purely monopolar to dipolar, quadropolar, etc., including mode-couplings. Our novel scheme is generally applicable to large classes of surface heterogeneities, and is explicitly applied here to Janus spheres with differently charged upper and lower hemispheres, revealing strong renormalization effects for all multipoles.Comment: 2 figure

    Influences of thermal environment on fish growth

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    Indexación: Scopus.Thermoregulation in ectothermic animals is influenced by the ability to effectively respond to thermal variations. While it is known that ectotherms are affected by thermal changes, it remains unknown whether physiological and/or metabolic traits are impacted by modifications to the thermal environment. Our research provides key evidence that fish ectotherms are highly influenced by thermal variability during development, which leads to important modifications at several metabolic levels (e.g., growth trajectories, microstructural alterations, muscle injuries, and molecular mechanisms). In Atlantic salmon (Salmo salar), a wide thermal range (ΔT 6.4°C) during development (posthatch larvae to juveniles) was associated with increases in key thermal performance measures for survival and growth trajectory. Other metabolic traits were also significantly influenced, such as size, muscle cellularity, and molecular growth regulators possibly affected by adaptive processes. In contrast, a restricted thermal range (ΔT 1.4°C) was detrimental to growth, survival, and cellular microstructure as muscle growth could not keep pace with increased metabolic demands. These findings provide a possible basic explanation for the effects of thermal environment during growth. In conclusion, our results highlight the key role of thermal range amplitude on survival and on interactions with major metabolism-regulating processes that have positive adaptive effects for organisms.http://onlinelibrary.wiley.com/doi/10.1002/ece3.3239/ful

    Advances in genetic breeding for processing tomatoes

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    de mejora genética en tomate para industria, asistido por marcadores moleculares, con el objetivo principal de generar cultivares autopolinizadas, especialmente orientadas a pequeños productores, como opción al uso de cultivares híbridas, resistentes a nematodos (Meloidogyne incognita, M. arenaria y M. javanica), peste negra (TSWV) y peca del tomate (Pseudomonas tomato syringae pv. tomato). En el proceso de mejora se siguió el método de retrocruza y selección genealógica. Las determinaciones de marcadores moleculares fueron realizadas por el Laboratorio de Biología Molecular INTA-Facultad de Ciencias Agrarias (UNCuyo). Las líneas avanzadas fueron evaluadas en el Programa Tomate 2000, con testigos híbridos difundidos en el gran cultivo. De los materiales evaluados a 2010-11, se han identificado homocigotos para resistencia combinada a nematodos y peste negra; igualmente para nematodos, peste negra y peca del tomate y homocigotos a nematodos, peste negra y peca del tomate. También se han determinado materiales heterocigotos en distintas combinaciones de los genes bajo estudio. Líneas avanzadas del programa de mejora, no arrojaron diferencias significativas con los testigos híbridos, en ensayos comparativos de rendimiento (kg·ha-1). Se analizan recomendaciones de cultivo y destino de los materiales.At the EEA La Consulta, INTA, a molecular assisted breeding program for processing tomatoes started in 2001 with the aim to generate self-pollinated cultivars, specially oriented for small growers. One of the main objectives of breeding program is the introduction of resistance to nematodes (Meloidoyne incognita, M. arenaria y M. javanica), tomato spotted wild virus (TSWV) and, tomato speck (Pseudomonas tomato syringae pv. tomato) as an alternative to use foreign and expensive hybrids cultivars. Breeding lines were obtained by pedigree and backcross selection methods.fake watches Early selection of resistant plants was done using molecular markers linked to nematode and TSWV. Molecular marker determinations were performed by the Laboratory of Molecular Biology of the INTA-Faculty of Agricultural Sciences (UNCuyo). Advanced breeding lines were tested against commercial hybrids in the Tomato 2000 Program. From all the materials evaluated up to 2010-11,a cartier replica we have identified homozygous lines that combine resistance to nematodes and tomato spotted wilt virus; homozygous lines that combine resistance to nematodes, tomato spotted wilt virus and tomato speck and homozygous lines resistant to nematodes, tomato spotted wilt virus and tomato speck (in separate genotypes). Also, heterozygous lines in different combinations for the genes under study. In comparative trials,fake watches the yiel (kg·ha-1) of the new lines did not have significant differences from controls. Horticultural recommendations are discussed.Fil: Gallardo, G. S.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Cuyo Mendoza-San Juan. Estación Experimental Agropecuaria La Consulta; Argentina;Fil: Masuelli, Ricardo Williams. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Mendoza. Instituto de Biologia Agricola de Mendoza; Argentina; Instituto Nacional de Tecnología Agropecuaria. Centro Regional Cuyo Mendoza-San Juan. Estación Experimental Agropecuaria La Consulta; Argentina; Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias; Argentina;Fil: Ferrer, S,. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Mendoza. Instituto de Biologia Agricola de Mendoza; Argentina; Instituto Nacional de Tecnología Agropecuaria. Centro Regional Cuyo Mendoza-San Juan. Estación Experimental Agropecuaria La Consulta; Argentina; Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias; Argentina

    A Possible Hybrid Cooling Channel for a Neutrino Factory

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    A Neutrino Factory requires an intense and well-cooled (in transverse phase space) muon beam. We discuss a hybrid approach for a linear 4D cooling channel consisting of high-pressure gas-filled RF cavities- potentially allowing high gradients without breakdown- and discrete LiH absorbers to provide the necessary energy loss that results in the required muon beam cooling. We report simulations of the channel performance and its comparison with the vacuum case; we also briefly discuss technical and safety issues associated with cavities filled with high-pressure hydrogen gas. Even with additional windows that might be needed for safety reasons, the channel performance is comparable to that of the original, all-vacuum Feasibility Study 2a channel on which our design is based. If tests demonstrate that the gas-filled RF cavities can operate effectively with an intense beam of ionizing particles passing through them, our approach would be an attractive way of avoiding possible breakdown problems with a vacuum RF channel.Comment: 3 pages, 9 figures; submitted to IPAC10, The First International Particle Accelerator Conference, May 23-28, 201

    Thoughts On Incorporating HPRF In A Linear Cooling Channel

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    We discuss a possible implementation of high-pressure gas-filled RF (HPRF) cavities in a linear cooling channel for muons and some of the technical issues that must be dealt with. The approach we describe is a hybrid approach that uses high-pressure hydrogen gas to avoid cavity breakdown, along with discrete LiH absorbers to provide the majority of the energy loss. Initial simulations show that the channel performs as well as the original vacuum RF channel while potentially avoiding the degradation in RF gradient associated with the strong magnetic field in the cooling channel.Comment: 5 pages, 8 figures, submitted to Proceedings of NUFACT0
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