Search results for " shape"
showing 10 items of 298 documents
Fluorescence excitation and emission spectroscopy on single MEH-PPV chains at low temperature.
2008
Fluorescence emission and excitation spectra of single MEH-PPV polymer molecules dispersed in thin PMMA films have been recorded at 1.2 and 20 K. We observe single as well as multichromophore emission in single chain emission spectra, whereby the relative fractions depend on the two different molecular weights (50 and 350 kDa) studied. The molecular weight also affects the distribution of peak emission maxima, which is monomodal (bimodal) for the low (high) molecular weight. The appearance of an additional "red" subpopulation for the high molecular weight sample is attributed to interactions of multiple chromophores from a sufficiently flexible single chain. The comparison of emission spect…
Beta-spectrum shapes of forbidden β decays
2018
The neutrinoless [Formula: see text] decay of atomic nuclei continues to attract fervent interest due to its potential to confirm the possible Majorana nature of the neutrino, and thus the nonconservation of the lepton number. At the same time, the direct dark matter experiments are looking for weakly interacting massive particles (WIMPs) through their scattering on nuclei. The neutrino-oscillation experiments on reactor antineutrinos base their analyses on speculations of [Formula: see text]-spectrum shapes of nuclear decays, thus leading to the notorious “reactor antineutrino anomaly.” In all these experimental efforts, one encounters the problem of [Formula: see text]-spectrum shapes of…
The size and shape of shells used by hermit crabs: A multivariate analysis of Clibanarius erythropus
2009
Shell attributes such as weight and shape affect the reproduction, growth, predator avoidance and behaviour of several hermit crab species. Although the importance of these attributes has been extensively investigated, it is still difficult to assess the relative role of size and shape. Multivariate techniques allow concise and efficient quantitative analysis of these multidimensional properties, and this paper aims to understand their role in determining patterns of hermit crab shell use. To this end, a multivariate approach based on a combination of size-unconstrained (shape) PCA and RDA ordination was used to model the biometrics of southern Mediterranean Clibanarius erythropus populatio…
Modeling of female human body shapes for apparel design based on cross mean sets
2014
This paper is concerned with a method to build prototypes of human bodies that can be used for apparel design. One of the most important issues in the apparel development process is to define a sizing system to provide a good fitting for the majority of the population. Since anthropometric measures do not present the same linear growth with size in each dimension, it is very important to find a prototype that represents as accurately as possible each class in the sizing system. In this paper we propose a method based on the concept of random compact mean set to define prototypes in apparel design. From a cloud of 3D points obtained with a 3D scanner a solid that represents the human body is…
El cuerpo materno en la red: entre el orden de lo ?deseable? y el de lo real
2019
El estilo de vida fitness se realiza en, y a través de, un entramado subjetivo y de poder en el que circulan y se ensamblan dispositivos empresariales, terapéuticos, sanitarios y de espectacularización de los cuerpos, tendientes a inscribir la vida de la población en las tramas conflictivas de un capitalismo heterosexista, neoliberal e informacional. En dicho marco, la temporalidad, metamorfosis y plasticidad del cuerpo materno irrumpe como problema y objeto de intervención de tecnologías diversas orientadas a ajustar su tamaño, forma y devenir a los parámetros de la vida activa y saludable. En escenarios digitales, dicha tensión se materializa, por un lado, a través de dispositivos visuale…
On Augmented Reality for the Learning of 3D-Geometric Contents: A Preliminary Exploratory Study with 6-Grade Primary Students
2019
Nowadays, Augmented Reality (AR) is one of the emerging technologies with a greater impact in the Education field. Research has proved that AR-based activities improve the teaching and learning processes. Also, the use of this type of technology in classroom facilitates the understanding of contents from different areas as Arts, Mathematics or Science. In this work we propose an AR-based instruction in order to explore the benefits in a 6th-grade Primary course related to 3D-geometry shapes. This first experiment, designed from an exploratory approach, will shed light on new study variables to perform new implementations whose conclusions become more consistent. The results obtained allow u…
Multi-parameter analysis of the obstacle scattering problem
2022
Abstract We consider the acoustic field scattered by a bounded impenetrable obstacle and we study its dependence upon a certain set of parameters. As usual, the problem is modeled by an exterior Dirichlet problem for the Helmholtz equation Δu + k 2 u = 0. We show that the solution u and its far field pattern u ∞ depend real analytically on the shape of the obstacle, the wave number k, and the Dirichlet datum. We also prove a similar result for the corresponding Dirichlet-to-Neumann map.
Jet shape modification in Pb-Pb collisions at √S[sub]N[sub]N= 2.76 TeV using two-particle correlations
2018
This thesis focuses on two separate topics. The first topic concerns the upgrade of the Time Projection Chamber (TPC) detector of the ALICE experiment. The upgrade will take place during the second Long Shutdown (2019-2020). The part of the upgrade I participated in was the replacement of the detector’s current readout electronics with Gas Electron Multiplier (GEM) foils. This change would allow for the continuous readout of the data, resulting in a hundredfold increase in the amount of data the ALICE experiment can process, as the TPC is the central tracking detector. I was involved in the Quality Assurance (QA) of these GEM foils. The advanced QA procedure consists of three measurements, a…
Antipredatory function of head shape for vipers and their mimics.
2011
Most research into the adaptive significance of warning signals has focused on the colouration and patterns of prey animals. However, behaviour, odour and body shape can also have signal functions and thereby reduce predators' willingness to attack defended prey. European vipers all have a distinctive triangular head shape; and they are all venomous. Several non-venomous snakes, including the subfamily Natricinae, commonly flatten their heads (also known as head triangulation) when disturbed. The adaptive significance of this potential behavioural mimicry has never been investigated. We experimentally tested if the triangular head shape typical of vipers offers protection against predation.…
Data from: Seasonal dynamics of Atlantic herring (Clupea harengus L.) populations spawning in the vicinity of marginal habitats
2015
Gillnet sampling and analyses of otolith shape, vertebral count and growth indicated the presence of three putative Atlantic herring (Clupea harengus L.) populations mixing together over the spawning season February–June inside and outside an inland brackish water lake (Landvikvannet) in southern Norway. Peak spawning of oceanic Norwegian spring spawners and coastal Skagerrak spring spawners occurred in March–April with small proportions of spawners entering the lake. In comparison, spawning of Landvik herring peaked in May–June with high proportions found inside the lake, which could be explained by local adaptations to the environmental conditions and seasonal changes of this marginal hab…