873 resultados para Sun and beach
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Current coastal-evolution models generally lack the ability to accurately predict bed level change in shallow (<~2 m) water, which is, at least partly, due to the preclusion of the effect of surface-induced turbulence on sand suspension and transport. As a first step to remedy this situation, we investigated the vertical structure of turbulence in the surf and swash zone using measurements collected under random shoaling and plunging waves on a steep (initially 1:15) field-scale sandy laboratory beach. Seaward of the swash zone, turbulence was measured with a vertical array of three Acoustic Doppler Velocimeters (ADVs), while in the swash zone two vertically spaced acoustic doppler velocimeter profilers (Vectrino profilers) were applied. The vertical turbulence structure evolves from bottom-dominated to approximately vertically uniform with an increase in the fraction of breaking waves to ~ 50%. In the swash zone, the turbulence is predominantly bottom-induced during the backwash and shows a homogeneous turbulence profile during uprush. We further find that the instantaneous turbulence kinetic energy is phase-coupled with the short-wave orbital motion under the plunging breakers, with higher levels shortly after the reversal from offshore to onshore motion (i.e. wavefront).
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Cadastral survey map showing lot lines, lot nos., dimensions, acreages, and proposed streets.
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Beach sands from the Rosa Marina locality (Adriatic coast, southern Italy) were analysed mainly microscopically in order to trace the source areas of their lithoclastic and bioclastic components. The main cropping out sedimentary units were also studied with the objective to identify the potential source areas of lithoclasts. This allowed to establish how the various rock units contribute to the formation of beach sands. The analysis of the bioclastic components allows to estimate the actual role of organisms regarding the supply of this material to the beach. Identification of taxa that are present in the beach sands as shell fragments or other remains was carried out at the genus or family level. Ecologi- cal investigation of the same beach and the recognition of sub-environments (mainly distinguished on the basis of the nature of the substrate and of the water depth) was the key topic that allowed to establish the actual source areas of bioclasts in the Rosa Marina beach sands. The sedimentological analysis (including a physical study of the beach and the calculation of some statistical parameters concerning the grain-size curves) shows that the Rosa Marina beach is nowadays subject to erosion.
Microclimate, development and productivity of robusta coffee shaded by rubber trees and at full sun.
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Existem poucos estudos sobre arborização de café conilon com seringueira. Objetivou-se avaliar o microclima, desenvolvimento e produtividade do cafeeiro conilon cultivado a pleno sol e sob sombreamento proporcionado pela seringueira. O experimento foi composto por uma lavoura de café conilon (Coffea canephora), cultivada a pleno sol e outra lavoura de café consorciada com seringueira (Hevea brasiliensis). A seringueira e o cafeeiro foram plantados no sentido Leste/Oeste, em Jaguaré, Espírito Santo, Brasil. Avaliou-se a luminosidade, temperatura e umidade relativa do ar, concentração foliar de nutrientes, medição dos internódios dos ramos plagiotrópicos e ortotrópicos, área foliar, índice relativo de clorofila, e a produtividade do cafeeiro. O sombreamento influenciou diretamente no microclima, reduzindo a temperatura do ar no verão e no inverno e aumentando a umidade relativa. A luminosidade no verão teve uma redução media de 905 lumens ft-2 ao longo de todo dia, equivalente a 72,49%, e no inverno de 1665 lumens ft-2, equivalente a 88,04%. O sombreamento proporcionou maior estiolamento dos ramos plagiotrópicos e ortotrópicos, bem como maior expansão foliar. A concentração foliar de Fe e Mn foram maiores no cafeeiro arborizado. A clorofila b e total estimada foram maior no cafeeiro cultivado a pleno sol. O denso sombreamento oferecido pela seringueira nas condições estudadas proporcionou perdas na produtividade do cafeeiro, contudo, ocorre a formação da seringueira.
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Predicting the evolution of a coastal cell requires the identification of the key drivers of morphology. Soft coastlines are naturally dynamic but severe storm events and even human intervention can accelerate any changes that are occurring. However, when erosive events such as barrier breaching occur with no obvious contributory factors, a deeper understanding of the underlying coastal processes is required. Ideally conclusions on morphological drivers should be drawn from field data collection and remote sensing over a long period of time. Unfortunately, when the Rossbeigh barrier beach in Dingle Bay, County Kerry, began to erode rapidly in the early 2000’s, eventually leading to it breaching in 2008, no such baseline data existed. This thesis presents a study of the morphodynamic evolution of the Inner Dingle Bay coastal system. The study combines existing coastal zone analysis approaches with experimental field data collection techniques and a novel approach to long term morphodynamic modelling to predict the evolution of the barrier beach inlet system. A conceptual model describing the long term evolution of Inner Dingle Bay in 5 stages post breaching was developed. The dominant coastal processes driving the evolution of the coastal system were identified and quantified. A new methodology of long term process based numerical modelling approach to coastal evolution was developed. This method was used to predict over 20 years of coastal evolution in Inner Dingle Bay. On a broader context this thesis utilised several experimental coastal zone data collection and analysis methods such as ocean radar and grain size trend analysis. These were applied during the study and their suitability to a dynamic coastal system was assessed.
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The use of natural areas for underwater coastal marine activities such as snorkelling is growing, but the amount of ecological and socioeconomic data on these activities is scarce and relates mainly to coral reef areas. Three underwater self-guided routes were designed at Marinha Beach (Algarve, Portugal), based on scientific information, with in situ interpretation and guidance, as a way to enhance biodiversity awareness and, hence, reduce the probability of human impacts. The routes were implemented in two consecutive summer seasons and after each season, visual census techniques were used to describe flora composition and cover area (seaweeds and seagrasses) in order to understand patterns and evaluate human impacts. Snorkelers' opinions and perceptions about several issues related to the routes' environmental education role (e.g. role in enhancing biocliversity awareness) were investigated by questionnaire after the snorkelling activity. An inter-annual difference inflora assemblages was found, probably associated to natural variability, rather than snorkelers' impacts. Results indicate that, in fact, in situ education and interpretation can raise environmental awareness if properly addressed, resulting in a satisfactory way of engaging snorkelers in the protection and in the conservation of the visited environments, thereby preventing negative ecological impacts. (C) 2015 Elsevier Ltd. All rights reserved.
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Rapidity-odd directed flow (v1) measurements for charged pions, protons, and antiprotons near midrapidity (y=0) are reported in sNN=7.7, 11.5, 19.6, 27, 39, 62.4, and 200 GeV Au+Au collisions as recorded by the STAR detector at the Relativistic Heavy Ion Collider. At intermediate impact parameters, the proton and net-proton slope parameter dv1/dy|y=0 shows a minimum between 11.5 and 19.6 GeV. In addition, the net-proton dv1/dy|y=0 changes sign twice between 7.7 and 39 GeV. The proton and net-proton results qualitatively resemble predictions of a hydrodynamic model with a first-order phase transition from hadronic matter to deconfined matter, and differ from hadronic transport calculations.
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To compare variations in bone mineral density (BMD) and body composition (BC) in depot-medroxyprogesterone acetate (DMPA) users and nonusers after providing counselling on healthy lifestyle habits. An exploratory study in which women aged 18 to 40 years participated: 29 new DMPA users and 25 new non-hormonal contraceptive users. All participants were advised on healthy lifestyle habits: sun exposure, walking and calcium intake. BMD and BC were assessed at baseline and 12 months later. Statistical analysis included the Mann-Whitney test or Student's t-test followed by multiple linear regression analysis. Compared to the controls, DMPA users had lower BMD at vertebrae L1 and L4 after 12 months of use. They also had a mean increase of 2 kg in total fat mass and an increase of 2.2% in body fat compared to the non-hormonal contraceptive users. BMD loss at L1 was less pronounced in DMPA users with a calcium intake ≥ 1 g/day compared to DMPA users with a lower calcium intake. DMPA use was apparently associated with lower BMD and an increase in fat mass at 12 months of use. Calcium intake ≥ 1 g/day attenuates BMD loss in DMPA users. Counselling on healthy lifestyle habits failed to achieve its aims.
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The aim of the present study was to evaluate the effect of soil characteristics (pH, macro- and micro-nutrients), environmental factors (temperature, humidity, period of the year and time of day of collection) and meteorological conditions (rain, sun, cloud and cloud/rain) on the flavonoid content of leaves of Passiflora incarnata L., Passifloraceae. The total flavonoid contents of leaf samples harvested from plants cultivated or collected under different conditions were quantified by high-performance liquid chromatography with ultraviolet detection (HPLC-UV/PAD). Chemometric treatment of the data by principal component (PCA) and hierarchic cluster analyses (HCA) showed that the samples did not present a specific classification in relation to the environmental and soil variables studied, and that the environmental variables were not significant in describing the data set. However, the levels of the elements Fe, B and Cu present in the soil showed an inverse correlation with the total flavonoid contents of the leaves of P. incarnata.
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Sandy beaches are among the most extensive environments in Brazil and are generally threatened by disorderly urban growth due to their location along the coast, where human populations tend to concentrate. This is especially true in southeastern Brazil, where the largest urban areas are located. Thus, better knowledge regarding these natural resources is of considerable importance. The surf zone of sandy beaches is inhabited by a number of fish species, including juveniles seeking both food and shelter from predators. An ecological survey was conducted in the surf zone of Itamambuca beach in the city of Ubatuba, São Paulo State, Brazil, in order to evaluate the composition, structure and dynamics of the fish fauna using community descriptors. Diurnal and nocturnal samples were taken with a beach seine at five oceanographic stations over a 12-month period. Water temperature and salinity were also recorded. A total of 2,147 individuals representing 34 species and 18 families were sampled. The main variation in fish fauna was detected on the diel level, followed by a spatial repartition possibly related to salinity. Seasonal variation was also observed. The five most important species in the overall context were Atherinella brasiliensis, Eucinostomus melanopterus, Mugil sp., Trachinotus goodei and Atherinella blackburni.
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We present measurements of net charge fluctuations in Au+Au collisions at s(NN)=19.6, 62.4, 130, and 200 GeV, Cu+Cu collisions at s(NN)=62.4 and 200 GeV, and p+p collisions at s=200 GeV using the dynamical net charge fluctuations measure nu(+-,dyn). We observe that the dynamical fluctuations are nonzero at all energies and exhibit a modest dependence on beam energy. A weak system size dependence is also observed. We examine the collision centrality dependence of the net charge fluctuations and find that dynamical net charge fluctuations violate 1/N(ch) scaling but display approximate 1/N(part) scaling. We also study the azimuthal and rapidity dependence of the net charge correlation strength and observe strong dependence on the azimuthal angular range and pseudorapidity widths integrated to measure the correlation.
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We present the first spin alignment measurements for the K*(0)(892) and phi(1020) vector mesons produced at midrapidity with transverse momenta up to 5 GeV/c at root s(NN) = 200 GeV at RHIC. The diagonal spin-density matrix elements with respect to the reaction plane in Au+Au collisions are rho(00) = 0.32 +/- 0.04 (stat) +/- 0.09 (syst) for the K*(0) (0.8 < p(T) < 5.0 GeV/c) and rho(00) = 0.34 +/- 0.02 (stat) +/- 0.03 (syst) for the phi (0.4 < p(T) < 5.0 GeV/c) and are constant with transverse momentum and collision centrality. The data are consistent with the unpolarized expectation of 1/3 and thus no evidence is found for the transfer of the orbital angular momentum of the colliding system to the vector-meson spins. Spin alignments for K(*0) and phi in Au+Au collisions were also measured with respect to the particle's production plane. The phi result, rho(00) = 0.41 +/- 0.02 (stat) +/- 0.04 (syst), is consistent with that in p+p collisions, rho(00) = 0.39 +/- 0.03 (stat) +/- 0.06 (syst), also measured in this work. The measurements thus constrain the possible size of polarization phenomena in the production dynamics of vector mesons.
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We present STAR results on the elliptic flow upsilon(2) Of charged hadrons, strange and multistrange particles from,root s(NN) = 200 GeV Au+Au collisions at the BNL Relativistic Heavy Ion Collider (RHIC). The detailed study of the centrality dependence of upsilon(2) over a broad transverse momentum range is presented. Comparisons of different analysis methods are made in order to estimate systematic uncertainties. To discuss the nonflow effect, we have performed the first analysis Of upsilon(2) with the Lee-Yang zero method for K(S)(0) and A. In the relatively low PT region, P(T) <= 2 GeV/c, a scaling with m(T) - m is observed for identified hadrons in each centrality bin studied. However, we do not observe nu 2(p(T))) scaled by the participant eccentricity to be independent of centrality. At higher PT, 2 1 <= PT <= 6 GeV/c, V2 scales with quark number for all hadrons studied. For the multistrange hadron Omega, which does not suffer appreciable hadronic interactions, the values of upsilon(2) are consistent with both m(T) - m scaling at low p(T) and number-of-quark scaling at intermediate p(T). As a function ofcollision centrality, an increase of p(T)-integrated upsilon(2) scaled by the participant eccentricity has been observed, indicating a stronger collective flow in more central Au+Au collisions.
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We present a re-analysis of the Geneva-Copenhagen survey, which benefits from the infrared flux method to improve the accuracy of the derived stellar effective temperatures and uses the latter to build a consistent and improved metallicity scale. Metallicities are calibrated on high-resolution spectroscopy and checked against four open clusters and a moving group, showing excellent consistency. The new temperature and metallicity scales provide a better match to theoretical isochrones, which are used for a Bayesian analysis of stellar ages. With respect to previous analyses, our stars are on average 100 K hotter and 0.1 dex more metal rich, which shift the peak of the metallicity distribution function around the solar value. From Stromgren photometry we are able to derive for the first time a proxy for [alpha/Fe] abundances, which enables us to perform a tentative dissection of the chemical thin and thick disc. We find evidence for the latter being composed of an old, mildly but systematically alpha-enhanced population that extends to super solar metallicities, in agreement with spectroscopic studies. Our revision offers the largest existing kinematically unbiased sample of the solar neighbourhood that contains full information on kinematics, metallicities, and ages and thus provides better constraints on the physical processes relevant in the build-up of the Milky Way disc, enabling a better understanding of the Sun in a Galactic context.
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The growing interest in solar twins is motivated by the possibility of comparing them directly to the Sun. To carry on this kind of analysis, we need to know their physical characteristics with precision. Our first objective is to use asteroseismology and interferometry on the brightest of them: 18 Sco. We observed the star during 12 nights with HARPS for seismology and used the PAVO beam-combiner at CHARA for interferometry. An average large frequency separation 134.4+/-0.3 mu Hz and angular and linear radiuses of 0.6759 +/- 0.0062 mas and 1.010 +/- 0.009 R(circle dot) were estimated. We used these values to derive the mass of the star, 1.02 +/- 0.03 M(circle dot).