Approach to rapid mission design and planning

Methods and techniques are described for implementation in automated computer systems to assess parametric data, capabilities, requirements and constraints for planning earth orbit missions. Mission planning and design procedures are defined using two types of typical missions as examples. These missions were the high energy Astronomical Observatory Satellite missions, and Small Applications Technology Satellite missions

Behavior of large-scale rectangular columns confined with FRP composites

This paper focuses on axially loaded, large-scale rectangular RC columns confined with fiber-reinforced polymer (FRP) wrapping. Experimental tests are conducted to obtain the stress-strain response and ultimate load for three field-size columns having different aspect ratios and/or corner radii. Effective transverse FRP failure strain and the effect of increasing confining action on the stress-strain behavior are examined. Existing strength models, the majority of which were developed for small-scale specimens, are applied to predict the structural response. Since some of them fail to adequately characterize the test data and others are complex and require significant calculation, a simple design-oriented model is developed. The new model is based on the confinement effectiveness coefficient, an aspect ratio coefficient, and a corner radius coefficient. It accurately predicts the axial ultimate strength of the large-scale columns at hand and, when applied to the small-scale columns studied by other investigators, produces reasonable results

Lunar targeting study: Lunar and planetary Ephemeris tapes

The Univac 1108 computer tape data formats are documented for the ephermeris tape generated by the Jet Propulsion Laboratory and the ephemeris tape used by the Quick Response Targeting Program (QRTP). Ephermeris tapes are used as the data source for the position and velocity components of those celestial bodies being considered in an integrated trajectory simulation program. The QRTP ephemeris tape has data only for lunar mission simulations. The JPL ephemeris tape has data for the moon and the nine planets. The ephemeris tapes, the data formats, the coordinate systems, and units are defined. The transformation from the mean-of-1950 coordinate system to the nearest mean Besselian year is given

Flight Flutter Testing of Rotary Wing Aircraft Using a Control System Oscillation Technique

A flight flutter testing technique is described in which the rotor controls are oscillated by series actuators to excite the rotor and airframe modes of interest, which are then allowed to decay. The moving block technique is then used to determine the damped frequency and damping variation with rotor speed. The method proved useful for tracking the stability of relatively well damped modes. The results of recently completed flight tests of an experimental soft-in-plane rotor are used to illustrate the technique. Included is a discussion of the application of this technique to investigation of the propeller whirl flutter stability characteristics of the NASA/Army XV-15 VTOL tilt rotor research aircraft

Electron paramagnetic resonance study of Eu2+ centers in melt-grown CsBr single crystals

The structure of Eu2+ monomer centers in CsBr single crystals is investigated using electron paramagnetic resonance (EPR) spectroscopy. These centers are produced by heating the melt-grown crystals above 600 K in vacuum followed by a rapid quench to room temperature (RT) or 77 K. The angular dependence of their EPR spectrum demonstrates that these centers have cubic symmetry. At RT the EPR spectrum decays by aggregation of the Eu2+ ions. This strongly contrasts with the situation for CsBr:Eu needle image plates synthesized by physical vapor deposition, where the Eu2+-related EPR spectrum was observed to exhibit long-term stability at RT

Handreiking ex ante evaluatie contraterrorismebeleid

Security and Global Affair

Numerical modelling of the debonding between CFRP strips and concrete in shear tests under static loads using different approaches

The present paper deals with the finite element (FE) analysis of bond slip between concrete and carbon fiber reinforced polymer (CFRP) strips in a single pull-out test under static loads. The commercial software LS-DYNA is used to simulate the test set-up using a plastic damage material model and an elastic material model for the concrete prism and the unidirectional CFRP strip, respectively. The bond interface between the concrete and the CFRP strip is simulated following three different approaches using a perfect bond model, a cohesive bond model and contact algorithms based on recently developed proposed bond slip models. The numerical model is validated based on experimental test results available from literature. The debonding failure mode and the delamination loads of the CFRP strip are predicted. The numerical results show a good agreement with the experimental data using the cohesive bond model. The perfect bond model gives an overestimation of the delamination loads and of the damage distribution in the concrete prism

Wireless flow-sensor to inspect spray rate controllers

In Belgium, the mandatory inspection of sprayers was already started up in 1996 and the 8th inspection cycle (2017-2018-2019) is currently running. The inspection of sprayers is performed by official and mobile teams ruled by two inspection authorities and the management is done by the Federal Ministry for Consumer Protection, Public Health and the Environment (FAVV). In the Flemish region the inspection is delegated to the Institute for Agricultural and Fisheries Research (ILVO). In the past decade the number of field crop sprayers equipped with a spray rate controller increased significantly. In the first inspection cycle (1996-1998), only 4.58% of the field crop sprayers were equipped with a spray rate controller in Flanders. In the 7th inspection cycle (2014-2016), this percentage increased significantly to 26.92%. As the original inspection method for spray rate controllers showed some lacks and was time consuming, ILVO developed a simple and reliable method to test rate controllers on field crop and orchard sprayers.In Belgium, the mandatory inspection of sprayers was already started up in 1996 and the 8th inspection cycle (2017-2018-2019) is currently running. The inspection of sprayers is performed by official and mobile teams ruled by two inspection authorities and the management is done by the Federal Ministry for Consumer Protection, Public Health and the Environment (FAVV). In the Flemish region the inspection is delegated to the Institute for Agricultural and Fisheries Research (ILVO). In the past decade the number of field crop sprayers equipped with a spray rate controller increased significantly. In the first inspection cycle (1996-1998), only 4.58% of the field crop sprayers were equipped with a spray rate controller in Flanders. In the 7th inspection cycle (2014-2016), this percentage increased significantly to 26.92%. As the original inspection method for spray rate controllers showed some lacks and was time consuming, ILVO developed a simple and reliable method to test rate controllers on field crop and orchard sprayers

Boost-HiC: computational enhancement of long-range contacts in chromosomal contact maps

International audienceGenome-wide chromosomal contact maps are widely used to uncover the 3D organisation of genomes. They rely on the collection of millions of contacting pairs of genomic loci. Contact frequencies at short range are usually well measured in experiments, while there is a lot of missing information about long-range contacts. We propose to use the sparse information contained in raw contact maps to determine high-confidence contact frequency between all pairs of loci. Our algorithmic procedure, Boost-HiC, enables the detection of Hi-C patterns such as chromosomal compartments at a resolution that would be otherwise only attainable by sequencing a hundred times deeper the experimental Hi-C library

Nederland mensenrechtengidsland?: Interview met Quirine Eijkman

Security and Global Affair