Best Possible Cut From Gemstones With New Machine

SOURCE

ScienceDaily (June 26, 2009) — Emeralds, rubies and the likes are referred to as colored gemstones by experts. They sparkle and shine with varying intensity, depending on the cut. A new machine can achieve the best possible cut and extract up to 30 per cent more precious stone from the raw material.

“We were astounded when our customer, Markus Wild, approached us and we were not at all certain whether mathematics could offer a solution for the very complex problem of volume optimization of gemstones,” says Dr. Anton Winterfeld from the Fraunhofer Institute for Industrial Mathematics ITWM. Jointly with his colleague Dr. Peter Klein, he will receive one of the 2009 Joseph von Fraunhofer prizes for the development of GemOpt, a new industrial process for the volume-optimized utilization of colored gemstones.
In contrast to diamonds, there are innumerable combinations of types and proportions of cut, and types of facet patterns for colored gemstones. When chosen correctly, the interplay of these variables ensures the luster in the stone, its shine. Sometimes just a few facets are sufficient to make a gemstone sparkle, sometimes several hundred. The task was to set limits on what seemed to be infinite and to calculate the optimal volume. The mathematical approach, which finally resulted in a solution, originated from the area of general semi-infinite optimization.
This involved a new type of algorithm, which had until now only been theoretically defined. The team at the ITWM continued to develop this approach and implemented it for this specific problem. The result is an outstanding achievement, also in scientific terms. The second essential part of GemOpt is process control, which Dr. Peter Klein has worked out. For this he ascertained precisely how raw gemstones behave when processed and transferred his findings to the control unit of the machine.
The machine runs fully automatically. First of all, the raw stone is measured. On the basis of these data, the computer calculates optimal embedments, proportions and facet patterns for different basic geometries. The customer then opts for one of the proposed solutions and the machine begins cutting. The process control unit is finely balanced, so that the machine does not split the stones as it cuts them.
The system then moves seamlessly on to the polishing step. The 17 axes ensure that the stone can move along any desired path. The machine cuts the facets to ten micrometers exactly – the stones are therefore perfectly geometric. A further advantage is that the machine can produce identical stones – ideal for necklaces. Cutting with the machine can result in up to 30 per cent more weight. This puts a significantly higher price on the stone.
Adapted from materials provided by Fraunhofer-Gesellschaft.

Near-Infrared LIDAR Helps Pilots

Source:

http://www.sciencedaily.com/releases/2007/08/070823120237.htm

Science Daily — Airline pilots will have more advance warning of potentially hazardous atmospheric conditions ¡V such as icing ¡V using a new near-infrared Light Detection and Ranging (LIDAR) system developed by scientists at RL Associates in Chester, Pa. The system, now in a prototype testing phase, will also provide better images in foggy, rainy or extremely hazy conditions, making it easier for pilots to take off and land in those conditions, thereby potentially reducing flight delays.
Right now, other experimental systems use visible green light to detect the different types of particles in the atmosphere. Most commercial planes, however, don't have this kind of system, and flights are grounded rather than risk a foggy landing or misidentifying clouds of icy particles. The RL Associates LIDAR system, which could be quickly commercially deployed, is slated for testing in approximately 18 months.
LIDAR exploits the same basic principle as radar, using light waves instead of radio waves. Lasers use light at wavelengths much smaller than radio waves, so they are much better at detecting very small objects. LIDAR already is frequently used in atmospheric physics ¡V but not on commercial planes ¡V to measure the densities of various particles in the middle and upper atmospheres. According to Mary Ludwig of RL Associates, the system uses a laser light beam that is polarized, or has its electric field pointing in a specific direction. The system beams the polarized infrared light out, and then records the amount of polarization that returns to the sensors. Rain and fog return a less polarized signal, and metal and people return a more polarized signal. The data is then processed to form an image of the ground, or could be translated into verbal commands if needed.
The system can better detect different types of particles in the atmosphere, such as ice, supercooled liquid or just regular water vapor. It can also identify the difference between water vapor and other kinds of substances, such as metal or the human body. Ludwig says the RL Associates system is the first of its kind to use near-infrared. The system also employs a "range-gated detector" that is only turned on for very short periods of time when the return signal is expected. This leads to a vastly improved signal-to-noise ratio, resulting in better images, particularly in obscuring conditions such as fog or haze.
Article: FThG4, "Near-Infrared LIDAR System for Hazard Detection and Mitigation Onboard Aircraft"
Note: This story has been adapted from a news release issued by Optical Society of America.

Fausto Intilla
www.oloscience.com