Heavy quark collisional energy loss in the quark-gluon plasma including finite relaxation time

In this paper, we calculate the soft-collisional energy loss of heavy quarks traversing the viscous quark-gluon plasma including the effects of a finite relaxation time $\tau_\pi$ on the energy loss. We find that the collisional energy loss depends appreciably on $\tau_\pi$ . In particular, for typical values of the viscosity-to-entropy ratio, we show that the energy loss obtained using $\tau_\pi$ = 0 can be $\sim$ 10$\%$ larger than the one obtained using $\tau_\pi$ = 0. Moreover, we find that the energy loss obtained using the kinetic theory expression for $\tau_\pi$ is much larger that the one obtained with the $\tau_\pi$ derived from the Anti de Sitter/Conformal Field Theory correspondence. Our results may be relevant in the modeling of heavy quark evolution through the quark-gluon plasma.Comment: v2: 5 pages, 4 figures, added references. Accepted for publication in Phys. Rev.

Estimating the mode of inheritance in genetic association studies of qualitative traits based on the degree of dominance index

<p>Abstract</p> <p>Background</p> <p>The biological justification for the choice of the genetic mode in genetic association studies (GAS) is seldom available. Then, the mode of inheritance is approximated by investigating a number of non-orthogonal genetic contrasts making the interpretation of results difficult.</p> <p>Methods</p> <p>We propose to define the mode of inheritance by the significance of the deviance of the co-dominant contrast and the degree of dominance (<it>h</it>), which is a function of two orthogonal contrasts (the co-dominant and additive). Non-dominance exists when the co-dominant contrast is non-significant and, hence, the risk effect of heterozygotes lies in the middle of the risk of the two homozygotes. Otherwise, dominance (including over- and under-dominance) is present and the direction of dominance depends on the value of <it>h</it>.</p> <p>Results</p> <p>Simulations show that <it>h </it>may capture the real mode of inheritance and it is affected by deviations from Hardy-Weinberg equilibrium (HWE). In addition, power for detecting significance of <it>h </it>when the study conforms to HWE rule increases with the degree of dominance and to some extent is related to the mutant allele frequency.</p> <p>Conclusion</p> <p>The introduction of the degree of dominance provides useful insights into the mode of inheritance in GAS.</p

Airport Level of Service: A Model according to Departing Passenger’s Perceptions at a Small-sized Airport

Purpose: This study proposes a conceptual model of level of service evaluation to a small-sized airport with a focus on departing passengers. Design/methodology: The variables selected to compose the model were chosen according to their adequacy to departing passengers and the airport’s characteristics. A survey was conducted, and, posteriorly, exploratory factor analysis was used in order to verify the adequacy of the conceptual model proposed and also to improve it according to the results obtained. Findings: The results show that the level of service of the airport is composed of three dimensions: airport characteristics, passenger processing, and prices. The relative importance of the dimensions according to their contribution to the composition of the airport’s overall level of service was also determined. Originality/value: The paper combines theoretical and practical findings in a model for level of service evaluation to a small-sized airport from an air transportation management perspective.Peer Reviewe

Impedance and Instability Studies in LEIR with Xenon

In 2017, the LEIR accelerator has been operated with Xe39+ beam for fixed target experiments in the SPS North Area. The different ion species, with respect to the standard Pb54+, allowed for additional comparative measurements of tune shift versus intensity at injection energy both in coasting and bunched beams. The fast transverse instability observed for high accumulated intensities has been as well characterized and additional observations relevant to impedance have been collected from longitudinal Schottky signal and BTF measurements. The results of these measurements are summarised and compared to the currently developed machine impedance model

Espalhamento Raman dependente da temperatura no condutor superionico B-Eucryptite

Orientador: Ram Sharan KatiyarDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb WataghinResumo: Usando técnicas de espalhamento Raman, estudamos os modos normais de vibração e a dinâmica do movimento iônico, no condutor superiônico b-Eucryptite, como função da temperatura, da temperatura ambiente a ~ 750ºC. Nossos resultados confirmaram que a alta condutividade iônica apresentada por ele (~ 10-2 W-1 cm-1, em 600ºC), pode ser explicado em termos do movimento altamente correlacionado de ions Li+, produzidos pelos canais estruturais e pela distribuição desordenada desses ions em temperaturas elevadas. Essa alta condutividade iônica é obtida por meio de uma transição de fase gradual de ordem desordem que se processa no intervalo de temperaturas de 500 a 600ºC. Como a estrutura do b-Eucryptite apresenta similaridades com a do quartzo, as freqüências dos fonons nos dois cristais são quase as mesmas. No entanto, desde que a zona de Brillouin do b-Eucryptite é metade da do quartzo, fonons característicos de pontos críticos no quartzo são ativos em Raman, no b-Eucryptite. Além disso, observamos o aparecimento de fatores extras nos espectros Raman do b-Eucryptite associados aos movimentos vibracionais e difusivos dos ions Li+Abstract: By using Raman scattering techniques, we have studied the normal modes of vibration and the dynamics of the ionic motion in the superionic conductor b-Eucryptite, as a function of temperature, from room temperature to ~ 750ºC. Our results have proved that the high ionic conductivity it displays (~ 10-2 W-1cm-1, at 600ºC), can be explained in terms of the highly correlatet Li+ motions, brought about by the structure channels and by the disordered distribution of these ions in high temperatures. This high ionic conductivity is achieved via a gradual order-disorder phase transition which takes place at the 500-600ºC range of temperatures. As the structure of the b-Eucryptite shows simililarities to quartz, the phonon frequencies in both crystals are nearly the same. However, since the b-Eucryptite Brillouin zone is halved compared with that of quartz, phonons characteristic of critical points in quartz are Raman active in b-Eucryptite, Furthermore we have noted the appearance of extra features in Raman spectra of b-Eucryptite, attributed to vibrational and diffusive motions of Li+ ionsMestradoFísicaMestre em Físic

Optical sensing systems based on Erbium-doped W-fiber

Orientadores: Carlos Kenichi Suzuki, João Batista RosolemTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia MecânicaResumo: Fibras ópticas de casca rebaixada (também conhecidas como fibras ópticas de dupla-casca ou fibras ópticas de perfil-"W") com cortes do modo fundamental proporcionam perdas distribuídas altas em comprimentos de onda longos e perdas baixas em comprimentos de onda curtos. A grandeza da brusca transição entre a perda baixa em comprimentos de onda curtos e a perda alta em comprimentos de onda longos excede 200 dB/km e é extremamente sensível à curvatura aplicada na fibra. O fenômeno é atribuído ao acoplamento modal entre o modo guiado no núcleo e os modos discretos guiados na casca externa. A fibra óptica ativa de casca rebaixada Er: Al/Ge/SiO2 (DC-EDF) pode ser projetada para ter um corte do modo fundamental próximo de 1530 nm o que proporciona supressão distribuída da emissão espontânea amplificada (ASE) na banda-C em proveito da ASE na banda-S. Este fenômeno, associado a um outro, o de perda induzida por curvatura, proporciona um modelo alternativo para obter amplificação óptica na banda-S, exigida para expandir a capacidade de sistemas de multiplexação por divisão de comprimentos de onda (WDM). Um laser à fibra óptica, configurado na forma de anel, de fibra óptica de casca rebaixada dopada com érbio, que pode ser sintonizado através de perdas induzidas por curvatura na fibra óptica, ou pelo uso de um filtro óptico sintonizável, também pode ser projetado. Devido às características de amplificação e "lasing" desenvolvidas para aplicação na banda-S, baseadas em propriedades únicas, a fibra DC-EDF foi base dos sistemas de sensores desenvolvidos neste trabalho. De fato, os sistemas de sensores propostos mostraram alta sensibilidade, larga faixa dinâmica, e ampla largura de banda, e podem ser usados para monitorar parâmetros estáticos, tais como força, pressão, deslocamentos e parâmetros dinâmicos usados em acústica e vibrações. Dois tipos de sistemas de sensores, com diferentes modelos, foram estudados: um sensor-amplificador e um sensor-laser. Os desempenhos desses sistemas de sensores na banda-S (1490 e 1510 nm) foram estudados e analisados nas condições estática e dinâmicaAbstract: Depressed-cladding (often referred to as dual-clad or "W"- fiber) fibers with fundamental-mode cutoffs provide high distributed losses at long wavelengths and low losses at short wavelengths. The magnitude of the abrupt transition between low-loss at short wavelengths and high-loss at long wavelengths exceeds 200 dB/km and is found to be extremely sensitive to fiber curvature. The phenomenon is attributed to mode coupling between the core-guided mode and the discrete modes guided in the outer cladding. The active depressed-cladding Er: Al/Ge/SiO2 fiber (DC ? EDF) may be designed to have a fundamental mode cutoff near 1530 nm and provides distributed suppression of C-band amplified spontaneous emission (ASE) to the advantage of that in the S-band. This phenomenon, associated with the mechanism of induced bending loss, provides an alternative approach to obtain amplification in S-band, required to expand the capacity of wavelength-division multiplexing (WDM) systems. A S-band depressed-cladding erbium-doped fiber ring laser which can be tuned through the active fiber bending losses or by using an optical tunable filter, can be designed as well. Due to the amplification and lasing characteristics developed for S-band, based on unique properties, the DC - EDF was the basis of the optical sensing systems developed in this work. In fact, the sensing systems proposed showed high sensitivity, high dynamic range and wide bandwidth, and can be used to monitor static parameters, such as force, pressure, displacement and dynamic parameters used in acoustics and vibrations. Two types of sensing systems, with different approaches, have been studied: an amplifier-sensor and a laser-sensor. The performances of these sensing systems in S-band (1490 and 1510 nm) were studied and analyzed in static and dynamic conditionsDoutoradoMateriais e Processos de FabricaçãoDoutor em Engenharia Mecânic

EFFECT OF INCREASING THE FERTILIZER DOSE ON BIOMASS PRODUCTION OF Eucalyptus dunnii Maiden

With the recent expansion of Eucalyptus dunnii Maiden cultivation in central region of Rio Grande do Sul state, recurrent questions arise from both research and operational silviculture, especially in relation to mineral fertilization. The objective of this study was to test the effect of fertilizer dose increase (150, 225 and 450 g plant-1 of N-P2O5-K2O, in 24:00:24 proportion) on the biomass production, carbon stock and nutrients in Eucalyptus dunnii trees cultivated in dystrophic Inceptisol, in central region of Rio Grande do Sul state, Brazil. This study revealed that there is no effect of the fertilizer dose increase on the accumulation of biomass, carbon and nutrients in components of Eucalyptus dunnii trees. The nutrients were more concentrated in leaves; in stemwood there was greater stock of carbon and potassium; in branches and stembark the calcium prevailed. Due to the significant biomass production, regardless of fertilizer dose, aiming at reducing costs and environmental impacts, it is recommended to apply mineral fertilization with 150 g plant-1 of N-P2O5-K2O, in 24:00:24 proportion, in Eucalyptus dunnii stand cultivated in dystrophic Inceptisol, in central region of Rio Grande do Sul state, Brazil

Fertilização em Eucalyptus dunnii Maiden no bioma Pampa - Brasil

In silviculture, mineral fertilization is necessary to supply the nutritional demand, however, the recommendation of the quantities to be applied should aim at maintaining the productive capacity of the soil. The purpose of this study is to test whether increasing the recommended fertilizer dose improves soil fertility and increases the productivity of Eucalyptus dunnii in sites in the central region of the Pampa biome, Brazil. The doses of 150 g (T0), 225 g (T1) and 450 g (T2) of N-P2O5-K2O were applied 24:00:24 per plant, after 14 months of planting. In all tested doses, the species productivity is considered satisfactory for the site. There was an improvement in soil fertility, especially in potassium contents, in addition to a higher individual volume of Eucalyptus dunnii trees after the application of the dose of 450 g plant-1 of N-P2O5-K2O, 24:00:24 in coverage (T2).Na silvicultura a fertilização mineral é necessária para suprir a demanda nutricional, no entanto, a recomendação das quantidades a serem aplicadas devem almejar à manutenção da capacidade produtiva do solo. O objetivo deste estudo é testar se o aumento da dose recomendada de fertilizante, melhora a fertilidade do solo e incrementa a produtividade de Eucalyptus dunnii em sítios da região central do bioma Pampa, Brasil. Foram aplicadas as doses de 150 g (T0), 225 g (T1) e 450 g (T2) de N-P2O5-K2O 24:00:24 por planta, após 14 meses do plantio. Em todas as doses testadas, a produtividade da espécie é considerada satisfatória para o sítio. Houve melhoria da fertilidade do solo, especialmente nos teores de potássio, além de maior volume individual das árvores de Eucalyptus dunnii após a aplicação da dose de 450 g planta-1 de N-P2O5-K2O, 24:00:24 em cobertura (T2)

Reproductive cycle and gonad development of the Northern Argentinean Mesodesma mactroides (Bivalvia: Mesodesmatidae)

The reproductive cycle and gonad development of the yellow clam Mesodesma mactroides was studied over a period of 24 months (January 2005?December 2006) at the Argentinean sandy beach Santa Teresita. Histological examination of gonadal tissue revealed that sex ratios did notsignificantly deviate from the proportion of 1:1 and no case of hermaphroditism was found. The reproductive cycle of M. mactroides followed an annual cyclicality, which was significantly correlated to monthly mean sea surface temperatures (SST). Oocytes showed highest abundance in winter, indicating a process of gonadal development and sexual maturation. The mean oocyte size decreased significantly during spring. Modal oocyte sizes decreased significantly during winter and late spring of each year, suggesting spawning events. The condition index was not useful in describing the annual reproductive cycle of M. mactroides. Ash-free, shell-free dry mass was chosen to detect the condition of the specimens, and this significantly correlated with monthly mean SST and the gametogenic cycle. Annual recruitment patterns during summer?autumn indicated a 3-month-long planktonic phase of M. mactroides. The reproduction cycle and gonad development of M. mactroides showed only weak differences between data from the present study and those collected 40 years ago.Fil: Herrmann, Marko. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina. Alfred Wegener Institute for Polar and Marine Research; AlemaniaFil: Fernandez Alfaya, Jose Elias. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Lepore, Mauro L.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Penchaszadeh, Pablo Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Laudien, Jurgen. Alfred Wegener Institute for Polar and Marine Research; Alemani