Wednesday, February 27, 2008

Transreflective liquid crystal display

A transreflective liquid crystal display is a liquid crystal display (LCD) that reflects most of the sunlight it is exposed to, and automatically increases or decreases the light emanating from the screen depending on how much light shines on it. Therefore, it reduces the need for manual light adjustment of the screen.

Transreflective liquid crystal displays use a retroreflector to transmit light when external sources of light are available, such as the sun or a lamp, and illuminate the screen well. When these sources are available but do not illuminate well, the display transmits its own light from a backlight at the rear of the display.

Friday, February 22, 2008

Materials intelligence and Air Sampling

Nuclear tests, including underground tests that vent into the atmosphere, produce fallout that not only indicates that a nuclear event has taken place, but, through radiochemical analysis of radionuclides in the fallout, characterize the technology and source of the device. For example, a pure fission device will have different fallout products from a boosted fission device, which, in turn, differ from various types of thermonuclear devices.

One real-world example is a review of how xenon by-product levels could be used to distinguish if air sampling from a North Korean test, either atmospheric testing or leakage from an underground test, could be used to determine if the bomb was nuclear, and, if so, whether the Primary was plutonium or highly-enriched uranium (HEU)

Sunday, February 17, 2008

Integral action

The integral term magnifies the effect of long-term steady-state errors, applying ever-increasing effort until they reduce to zero. In the example of the furnace above working at various temperatures, if the heat being applied does not bring the furnace up to setpoint, for whatever reason, integral action increasingly moves the proportional band relative to the setpoint until the time-integral of the MV error is reduced to zero and the setpoint is achieved.

Saturday, February 09, 2008

Systems engineering

Systems Engineering is an interdisciplinary approach and means for enabling the realization and deployment of successful systems. It can be viewed as the application of engineering techniques to the engineering of systems, as well as the application of a systems approach to engineering efforts. Systems Engineering integrates other disciplines and specialty groups into a team effort, forming a structured development process that proceeds from concept to production to operation and disposal. Systems Engineering considers both the business and the technical needs of all customers, with the goal of providing a quality product that meets the user needs.