Search results for "Diameter"
showing 10 items of 189 documents
In-line holography of cloud volumes applied to the measurement of raindrops and snowflakes
1998
Abstract The ground-based HODAR (HOlographic Droplet and Aerosol Recording) of the University of Mainz has been operational since 1989 on the Kleiner Feldberg Mountain Observatory near Frankfurt/Main, Germany, in a `small volume' configuration. With this setup an air volume of approximately 1 l can be in situ recorded, which allows it to image all aerosol particles and droplets with diameter larger than 6 μm contained in the sample volume in situ. Recently the beam diameter and optical path length of the inline system have been enlarged such that large cloud volumes (approximately 500 l) can be recorded on single holograms. During the holographic image reconstruction step in the laboratory,…
Inverse problem for tripotential measures in the study of buried cavities
1996
This paper presents a solution to the inverse electrical problem for the interpretation of apparent resistivity anomalies due to empty buried cavities of quasi-spherical shape when tripotential measures are carried out. The anomalies of the apparent resistivities ra,rb andrg,and the composed resistivitiesrmand rt were previously calculated for a sufficient class of spherical models of resistivity anomalies. Then, for the whole class of models, some functionals of spatial distribution of the apparent and composed resistivity were identified and analyzed. They represent the average characteristics of the anomalies and, depending in a simple way on the fundamental parameters of the sources of …
Calibrating the Operational Beam Width and Maximum Range of a Ship Radar Used for Bird Observations
2010
In order to analyse quantitative radar observations of bird movements, one needs to know the dimensions of the air space surveyed by the radar. The present study shows how to calibrate the operational beam width and the maximum range of any radar for cross sections for different body sizes of songbirds. The trial used an X-band fan beam ship radar of 25 KW (Furuno Fr-2125) and a captive balloon. Metal spheres of different diameters, fastened to the bottom of the balloon at defined distances, corresponding to the radar cross sections of song birds, were moved in all three dimensions of the air space. Simultaneously to the location by radar, the position of the suspended sphere was measured b…
High-power laser-beam characteristics
2004
Applications of high-power lasers are very important, especially for cutting and welding. As it is known, laser-beam characteristics have not constant value in time. So we may have suitable testing methods which allow us to determine the principal beam characteristics. The testing methods have to be very accurate, very efficient and in the same time very short as duration. We must apply a 3-dimensional intensity analysis, to the photonic beam we are studying. The number of industrial applications of lasers is increasing. An important thing is to know the optical characteristics of the laser that we study. Only the complete knowledge of the laser parameters allows controlling the process. Fo…
Fibre Bragg gratings tuned and chirped using magnetic fields
1997
The authors report on the use of magnetic fields in conjunction with magnetostrictive materials for tuning and chirping optical fibre Bragg gratings. The Bragg wavelength shifts as a consequence of the strain induced in the fibre by a magnetostrictive rod when a magnetic field is applied. A tuning range of 1.1 nm has been achieved by a magnetic field of 103 mT and the grating has been chirped by applying non-uniform magnetic fields.
Short-term response of the Ca cycle of a montane forest in Ecuador to low experimental CaCl2 additions
2013
The tropical montane forests of the E Andean cordillera in Ecuador receive episodic Sahara-dust inputs particularly increasing Ca deposition. We added CaCl2 to isolate the effect of Ca deposition by Sahara dust to tropical montane forest from the simultaneously occurring pH effect. We examined components of the Ca cycle at four control plots and four plots with added Ca (2 x 5kg ha(-1) Ca annually as CaCl2) in a random arrangement. Between August 2007 and December 2009 (four applications of Ca), we determined Ca concentrations and fluxes in litter leachate, mineral soil solution (0.15 and 0.30 m depths), throughfall, and fine litterfall and Al concentrations and speciation in soil solutions…
Gibberellic acid and flower bud development in loquat (Eriobotrya japonica Lindl.)
2011
The application of gibberellic acid (GA 3) to the whole loquat tree from mid-May to early June and from early August to the onset of flowering, significantly reduced the number of premature flowering shoots per current shoot and per m 3 of canopy, and so reduced the total number of panicles per m 3 of canopy. The number of vegetative shoots per m 3 of canopy was also significantly reduced by applying GA 3. The response depended on the concentration applied and produced optimal results at 50mgl -1. Differences in the number of flowers per panicle and leaves per shoot were not significantly modified by the treatment. Nevertheless, GA 3 applied directly to the developing apex near to flower di…
The organismic and the continuous approaches applied to phytosociological relationships in a lowland neotropical forest, Venezuela
2011
Abstract The Organismic and the Continuous theories are traditionally considered as antagonist in ecology studies. In this research, we make the floristic characterization of different forest communities and establish the corresponding classification, taking into account the approaches derived from the theories aforementioned. We used 1 ha plots to evaluate individuals bigger than 10 cm dbh (diameter at breast height). In each one of that plots, four sub-plots of 100 m2 were measured, to study all the spermatophyta in the understory. The data obtained were considered in an Enlarged Importance Index (EII), for each species in each plot. Then, the phytosociological relationships were establis…
Necessary Catheter Diameters for Mechanical Thrombectomy with ADAPT
2017
BACKGROUND AND PURPOSE: Large-bore catheters allow mechanical thrombectomy in ischemic stroke by engaging and retrieving clots without additional devices (direct aspiration first-pass technique [ADAPT]). The purpose of this study was to establish a model for minimal catheter diameters needed for ADAPT. MATERIALS AND METHODS: We established a theoretic model for the calculation of minimal catheter diameters needed for ADAPT. We then verified its validity in 28 ADAPT maneuvers in a porcine in vivo model. To account for different mechanical thrombectomy techniques, we factored in ADAPT with/without a hypothetic 0.021-inch microcatheter or 0.014-inch microwire inside the lumen of the aspiration…
Constancy of diameter through the cell cycle ofSalmonella typhimurium LT2
1982
Measurements of cell diameter and length inSalmonella typhimurium LT2 cells were correlated using both light and electron microscopy. In cultures growing at high, intermediate, and low rates, cell diameter does not change with length. This constancy is also maintained in septated cells before division. Since length increases continuously with cell age, the above observations mean that cells maintain a constant diameter during the cell cycle.