Search results for "Direct observation"
showing 10 items of 37 documents
Modes of motion in a confined colloidal suspension under shear
2004
We investigated aqueous suspensions of charged polystyrene latex spheres at low salt concentration under the combined influence of steady shear and confining walls. Their equilibrium structure was adjusted via the particle and salt concentration to be either fluid or body centred cubic. Using high-resolution real-space microscopy, we here present a first direct observation of collective modes of motion under shear. As a function of either shear rate and/or salt concentration, we find a continuous transition from registered to free sliding of layers accompanied by an equally continuous structural rearrangement lowering the dimensionality of long-ranged order.
Validez factorial de una escala de generatividad en español: ¿otra escala con efectos de método?
2017
Introducción: Erikson (1950) utilizó el término “generatividad” por primera vez y se refiere al estado de adultez en el ciclo de vida, lo que implica procreatividad, productividad y creatividad e impulsa el desarrollo de la propia identidad. Existen varias formas de medir la generatividad como las entrevistas, la observación directa, los estudios de caso o los cuestionarios de autoinforme. El método más utilizado es el autoinforme y, entre las escalas disponibles, una de las más destacadas es la Escala de Generatividad de Loyola (EGL). La EGL es una medida de autoinforme que consta de veinte ítems que miden un factor general de generatividad.Objetivo: este estudio examinó la validez factori…
Improved limit on the directly measured antiproton lifetime
2017
Continuous monitoring of a cloud of antiprotons stored in a Penning trap for 405 days enables us to set an improved limit on the directly measured antiproton lifetime. From our measurements we extract a storage time of $3.15\times {10}^{8}$ equivalent antiproton-seconds, resulting in a lower lifetime limit of ${\tau }_{\bar{{\rm{p}}}}\gt 10.2\,{\rm{a}}$ with a confidence level of $68 \% $. This result improves the limit on charge-parity-time violation in antiproton decays based on direct observation by a factor of 7.
Direct observation of a buckling transition during the formation of thin colloidal crystals
2007
We have investigated a colloidal suspension in a thin wedge formed by two glass plates in the presence of a lateral pressure. Starting with a single hexagonal layer, with increasing separation between the glass plates additional layers are added. This process is accompanied by a number of structural transitions necessary to maintain a high packing fraction under the given boundary conditions. Besides the well-known sequence of hexagonal and quadratic phases, we observe two new phases which are identified with the buckling and the rhombic phase recently predicted by other authors.
TUNGAU PADA DAUN MANGGA (Mangifera Indica)
2014
Mites have hostplant specifications or host plants. Mites can be destructive and deadly of which is the host plants a mango crop. Mites on mango crops will cause the leaves yellow and fall off prematurely. This is will lead to the disruption of the productivity of mango. It is necessary for research to identify the mites that infect the mango crop. The method is carried out by direct observation. Mites were taken from the surface of mango leaves later in preservation with several levels of concentration of alcohol, and polyvinyl laktofenol. Then, observed under a microscope and documented for identification purposes. Mites on the leaf surface of manalagi mango (<em>Mangifera indica<…
Directly Observed Physical Activity among 3-Year-Olds in Finnish Childcare
2014
The main purpose of the study was to determine 3-year-olds’ physical activity levels and how these vary across season, gender, time of day, location, and the physical and social environment in childcare settings in Finland. A modified version of the Observational System for Recording Physical Activity in Children-Preschool (OSRAC-P) was used to measure physical activity levels and contextual variables (e.g., group composition, prompts) of children attending childcare centres. In total, 81 children (42 boys and 39 girls) were observed in autumn and in winter. Three-level linear regression analyses were used to assess differences between the seasons in the association between the context vari…
Observation of Photon Polarization in theb→sγTransition
2014
This Letter presents a study of the flavor-changing neutral current radiative $B^{\pm} \to K^{\pm}\pi^{\mp}\pi^{\pm}\gamma$ decays performed using data collected in proton-proton collisions with the LHCb detector at $7$ and $8\,$TeV center-of-mass energies. In this sample, corresponding to an integrated luminosity of $3\,\text{fb}^{-1}$, nearly $14\,000$ signal events are reconstructed and selected, containing all possible intermediate resonances with a $K^{\pm}\pi^{\mp}\pi^{\pm}$ final state in the $[1.1, 1.9]\,$GeV/$c^{2}$ mass range. The distribution of the angle of the photon direction with respect to the plane defined by the final-state hadrons in their rest frame is studied in interva…
Observation directe de la croissance d'hydrosilicate de calcium sur des surfaces d'alité et de silice par microscopie à force atomique
1998
Direct observation of the growth of calcium silicate hydrates, the tricalcium silicate hydration products, at the solid-solution interface were performed by atomic force microscopy. The covering of the surface of alite or silica by a three-dimensional oriented aggregation of nano particles of calcium silicate hydrate is always observed whatever the sample. All observations and quantifications made on calcium silicate growth at the submicronic level are in agreement with the data deduced from the study of the system evolution at the macroscopic level.
Direct observation of smectic layers in side chain liquid crystal polymer films
1987
Abstract By applying stringent conditions to the imaging process it has been possible to produce electron micrographs of the smectic planes in a highly beam sensitive polymethcrylate side chain liquid crystal polymer. These planes show a high degree of internal perfection, while, at the same time, showing clear evidence of curvature. The director orientation was determined over a fairly large region.
Hydraulic jumps at drop and abrupt enlargement in rectangular channel
2002
The different types of hydraulic jumps that occur in a rectangular channel at an abrupt increase in section are experimentally studied. The abrupt section increase is due to both a drop and an increase in the channel width. Experiments were carried out with three different values of the ratio L/l between the channel widths respectively downstream and upstream of the abrupt section increase. For each L/l value five values of Froude number F1, of the supercritical flow upstream of the section increase were considered, and for each of them live values of the depth y1 of the same flow. The experiments showed that, as the depth y2 of the downstream subcritical flow increases, several types of hy…