Search results for "Fragment size"
showing 4 items of 4 documents
Wind tunnel study on the size distribution of droplets after collision induced breakup of levitating water drops
2018
Abstract Wind tunnel experiments on collisions between drop pairs of 2.5 and 0.5 mm diameter have been performed and the coalescence and breakup events have been recorded by a high-speed digital camera. From the comprehensive analysis of the captured images, the most important parameters utilized in numerical models, such as coalescence efficiency, breakup type, number of fragments and fragment size distribution after breakup were determined. The experimentally obtained parameters have been compared to parameterizations based on earlier laboratory studies of Low and List, and on direct numerical simulations. A very good agreement between experimental results and parameterizations has been f…
Solution for the fragment-size distribution in a crack-branching model of fragmentation
2007
It is well established that rapidly propagating cracks in brittle material are unstable such that they generate side branches. It is also known that cracks are attracted by free surfaces, which means that they attract each other. This information is used here to formulate a generic model of fragmentation in which the small-size part of the fragment-size distribution results from merged crack branches in the damage zones along the paths of the propagating cracks. This model is solved under rather general assumptions for the fragment-size distribution. The model leads to a generic distribution S(-gamma) exp(-S/S(0)) for fragment sizes S, where gamma = 2d-1/d with d the Euclidean dimension, an…
Report of a european collaborative exercise comparing DNA typing results using a single locus VNTR probe
1991
A collaborative exercise was carried out in 1989 among 12 European forensic laboratories using the single locus VNTR probe pYNH24, the restriction enzyme HinfI, the same set of human genomic DNA samples, and a standardized DNA size marker. The objectives of the exercise were: (1) to study the degree of variation within and between laboratories, (2) to obtain information on requirements for technical standardization allowing the exchange of typing results and (3) to compare different approaches for the identification of allelic DNA fragments of unknown size. Each laboratory carried out up to 10 independent typing experiments using the same DNA samples. The results were analysed independently…
What are the biological determinants of regeneration of perennial weeds? Effect of fragment weight and bud number on the regrowth of five perennial w…
2022
Perennial weeds have become an increasing problem with the reduction of herbicide use andtillage. Because of their capacity to regenerate from vegetative organs, such as roots andrhizomes, they must be controlled with different management techniques than annuals. Todate, few studies exist on this topic and farmers often lack solutions to control perennials intheir cropping systems. Management strategies must focus on the depletion of theregenerative organ reserves to hamper the production of new shoots. However, there is aneed for a better understanding of below-ground organs physiology and the determiningfactors of their regrowth capacities.Our aim was to assess the number of shoots and th…