The use of high-pressure waterjets as a method for enhancing the performance of mechanical cutting tools has been well documented over the years. However, concurrent with this development for drag bit tools, there has been some evidence that the combination was not an effective one. By using sectioned samples of rock indented with a spherical indentor (of the type used in percussive drilling) t...

PURPOSE To raise awareness of the importance of prompt and appropriate imaging in patients presenting with signs and symptoms suggestive of idiopathic intracranial hypertension. METHODS Case report with diagnostic tests and discussion of management options. RESULTS A 15-year-old girl presenting with bilateral optic disc swelling was noted to have extensive thrombosis of intracerebral venous...

Abeli, T., Dalrymple, S.E., Mondoni, A., Orsenigo, S., and Rossi, G. 2014. Integrating a biogeographical approach into assisted colonization activities is urgently needed. Plant Biosyst. 148(6):13551357. Adamidis, G.C., Dimitrakopoulos, P.G., Manolis, A., and Papageorgiou, A.C. 2014. Genetic diversity and population structure of the serpentine endemic Ni hyperaccumulator Alyssum lesbiacum. Plan...

We present the first unrestricted, three-dimensional relativistic hydrodynamical calculations of the blob of gas associated with the jet producing a gamma-ray burst. We investigate the deceleration phase of the blob corresponding to the time when afterglow radiation is produced, concentrating on the transition in which the relativistic beaming γ goes from being less than θ, where γ is the bulk ...

Salps are barrel-shaped marine invertebrates that swim by jet propulsion. Morphological variations among species and life-cycle stages are accompanied by differences in swimming mode. The goal of this investigation was to compare propulsive jet wakes and swimming performance variables among morphologically distinct salp species (Pegea confoederata, Weelia (Salpa) cylindrica, Cyclosalpa sp.) and...

The objective of this study was to determine the contribution of a plant’s foliage to the total plant’s hydrodynamic drag. Experiments were conducted in a laboratory flume using samples of vegetation with different physical forms and biomechanical properties: Branches of pine Pinus sylvestris and ivy stipes Glechoma hederacea . The drag force was measured directly using a strain gauge technique...

The computation of boundary layer properties and laminar-to-turbulent transition location is a very complex problem, generally not undertaken in the context of aircraft design. Yet if an aircraft is to exploit the advantages of laminar flow and proper trade-offs between inviscid drag, structural weight, and skin friction are to be made, this is just what must be done. This paper summarizes a de...

SUMMARY There is a need for a wave drag method that combines the speed of handbook methods with the accuracy of computational methods. Especially determining the onset of wave drag as well as the initial drag rise is important in initial design stages. Meta-models allow this by capturing the trends present in previously computed data, providing an accurate and fast representation. In this repor...

We numerically compute light and polarisation curves of γ-ray burst afterglows for various configurations of the jet luminosity structure and for different dynamical evolutions. We especially consider the standard homogeneous “top hat” jet and the “universal structured jet” with power-law wings. We also investigate a possible more physical variation of the “top hat” model: the “Gaussian jet”. T...

The flying fish (family Exocoetidae) is an exceptional marine flying vertebrate, utilizing the advantages of moving in two different media, i.e. swimming in water and flying in air. Despite some physical limitations by moving in both water and air, the flying fish has evolved to have good aerodynamic designs (such as the hypertrophied fins and cylindrical body with a ventrally flattened surface...