Wednesday, December 31, 2014
Tuesday, December 30, 2014
"The Extreme Accuracy Tasked Ordnance (EXACTO) system seeks to improve sniper effectiveness and enhance troop safety by allowing greater shooter standoff range and reduction in target engagement timelines. The objective of the EXACTO program is to revolutionize rifle accuracy and range by developing the first ever guided small-caliber bullet. The EXACTO 50- caliber round and optical sighting technology expects to greatly extend the day and nighttime range over current state-of-the-art sniper systems. The system combines a maneuverable bullet and a real-time guidance system to track and deliver the projectile to the target, allowing the bullet to change path during flight to compensate for any unexpected factors that may drive it off course."
Monday, December 29, 2014
Tuesday, December 23, 2014
Monday, December 15, 2014
Saturday, December 6, 2014
"This whole skating season's been incredible. I've been out for nine days in a row. We went through 11 lakes and rivers one day. We only needed to walk 1.2 km of the stretch of four mil, the rest went to go on fine ice. "
Friday, December 5, 2014
... Fails at T-10 seconds and freezes while buffering! All I get is a few frames like this mid launch. Maybe with a few billion dollars more they will master late 1990's video streaming technology.
"Vortices created by the imbalance of a centrifugal force and a radial pressure gradient in a curved pipe move fluid from the inner wall (left side) towards the outer wall. These so called 'Dean vortices' (referring to the two symmetric structures in the rightmost figure) are common features of flows in curved geometries and occur in nature, such as in rivers, and technical applications, such as in heat exchangers and piping systems, where they are sometimes specifically generated for particle separation or filtration purposes.
By measuring the speed of tracer particles it is possible to obtain snapshots of the three dimensional velocity field in a cross plane and thereby capture the unsteady behavior of the vortices under turbulent flow conditions. Surrounded by an irregular and chaotic environment, the couple of 'undetermined' vortices appears to 'dance.' Sometimes they dance together while at other times one of them is taking the lead by swinging its partner (referring to the three snapshots to the left). Nonetheless, on average, they successfully manage to keep up an ordered, laminar-like, appearance as a harmonic couple."
Wednesday, December 3, 2014
"On October 14, 1966, a "boilerplate" full Saturn V and Apollo spacecraft stack inside the Vehicle Assembly Building is rocked back and forth by employees pushing with their feet and pulling with a rope so that stability and stresses which might result from winds at the launch pad can be measured. During the test the escape tower at the top of the Saturn V broke off and fell, but no one was injured."
Monday, December 1, 2014
Sunday, November 30, 2014
Tuesday, November 25, 2014
Sunday, November 23, 2014
Friday, November 21, 2014
Thursday, November 20, 2014
"The energy deposition in a liquid drop on a nanosecond time scale by impact of a laser pulse can induce various reactions, such as vaporization or plasma generation. The response of the drop can be extremely violent: The drop gets strongly deformed and propelled forward at several m/s, and subsequently breaks up or even explodes. These effects are used in a controlled manner during the generation of extreme ultraviolet (EUV) light in nanolithography machines for the fabrication of leading-edge semiconductor microchips. Detailed understanding of the fundamentals of this process is of key importance in order to advance the latest lithography machines."
"In this video we show the impact of a focused laser pulse onto a millimeter-size drop in a regime comparable to what can be found in lithography machines. The drop’s life was recorded for various impact conditions by high-speed imaging at 20 000 frames per second (FPS). The high reproducibility of the dynamics allowed us to use stroboscopic illumination with nanosecond exposure times leading to an effective frame rate of 10 million FPS. We present a scaling law and compare experimental results to numerical simulations, in order to show how the drop is propelled and deformed."
Authors: Alexander L. Klein, Wilco Bouwhuis, Claas Willem Visser, Henri Lhuissier, Chao Sun, Jacco H. Snoeijer, Emmanuel Villermaux, Detlef Lohse, and Hanneke Gelderblom