Active devices

Electronic. Diamonds have been used as thermistors and radiation detectors, but inhomogeneities within the crystals have seriously limited these appHcations where diamond is an active device. This situation is rapidly changing with the availabiHty of mote perfect stones of controUed chemistry from modem synthesis methods. The defect stmcture also affects thermal conductivity, but cost and size are more serious limitations on the use of diamond as a heat sink material for electronic devices. 

Fermentation Processes. The efficient production of penicillin, yeasts, and single-ceUed protein by fermentation requires defoamers to control gas evolution during the reaction. Animal fats such as lard [61789-99-9] were formerly used as a combined defoamer and nutrient, but now more effective proprietary products are usually employed. Defoamer appHcation technology has also improved. For example, in modem yeast production faciHties, the defoamers are introduced by means of automatic electrode-activated devices. One concern in the use of defoamers in fermentation processes is the potential fouHng of membranes during downstream ultrafiltration (qv). SiHcone antifoams (43,44) seem less troubled by this problem than other materials. 

Fieat activated device triggers CO2 or inert gas blanket... 

Secondary containment systems are best described as passive protective systems. They do not eliminate or prevent a spill or leak, but they can significantly moderate the impact without the need for any active device. Also, containment systems can be defeated by manual or active design features. For example, a dike may have a drain valve to remove rain water, and the valve could be left open. A door in a containment building could be left open. 

As vapor rates decrease, the tray activity also decreases. There eventually comes a point at which some of the active devices (valves or bubble caps) become inactive. Liquid passing these inactive devices gets very little contact with vapor. At very low vapor rates, the vapor activity will concentrate only in certain sections of the tray (or, in the limit, one bubble cap or one valve). At this point, it is possible that liquid may flow across the entire active area without ever contacting a significant amount ot vapor. This will result in very low tray efficiencies for a distillation process. Nothing can be done with a bubble cap tray to compensate for this. 

Payload. Generally, that part of a load that is expendable, deliverable, or ready for use in direct accomplishment of the mission. The warhead, its container, and activating devices in a military missile. The satellite or research vehicle of a space probe or research missile Refs 1) Anon, OrdTechTeim (1962), 220 2) Anon, Dictionary of United States Military Terms for Joint Usage , JCS Pub 1 (1964), 108... 

Liquid-cooled cold plates perform a function analogous to that of air-cooled heat sinks. Unlike heat pipes, they may be considered active devices in that the liquid is usually forced through them by a pump. 

Mode ofaction active devices depend on a source of electrical energy or other power, excluding gravity or the patient to perform their function. 

Additional rules applicable to active devices Rule 9... 

All active devices intended to control or monitor the performance of active therapeutic devices in Class Mb, or intended directly to influence the performance of such devices are in Class Mb. 

Active devices intended to emit ionizing radiation and intended for diagnostic and therapeutic interventional radiology including devices which control or monitor such devices, or which directly influence their performance, are in Class lib. 

All active devices intended to administer and/or remove medicines, body liquids or other substances to or from the body are in Class lla, unless this is done in a manner ... 

LOPA is a semi-quantitative tool for analyzing and assessing risk. This method includes simplified methods to characterize the consequences and estimate the frequencies. Various layers of protection are added to a process, for example, to lower the frequency of the undesired consequences. The protection layers may include inherently safer concepts the basic process control system safety instrumented functions passive devices, such as dikes or blast walls active devices, such as relief valves and human intervention. This concept of layers of protection is illustrated in Figure 11-16. The combined effects of the protection layers and the consequences are then compared against some risk tolerance criteria. 

A tandem-in-space mass spectrometer consists of an ion source, a precursor ion activation device, and at least two nontrapping mass analyzers. The first mass analyzer is used to select precursor ions within a narrow m/z range. Isolated precursor ions are allowed to enter the ion activation device, for example, a gas-filled collision cell, where they dissociate. Created fragments continue on to the second mass analyzer for analysis. The second mass analyzer can either acquire a full mass fragment spectrum or be set to monitor a selected, narrow, m/z range. In principle the second mass analyzer could be followed by more ion activation devices and mass analyzers for MSn experiments. However, due to rapidly decreasing transmission and increasing experimental... 

The hardwired ESD activation means is usually a push in knob or button. Confirmed action of the push button should be always be required to manually activate the ESD system in order to prevent accidental activations. Most commonly a protective cover is fitted over any of the push button or manual activation devices. All devices should only be manually resettable. 

Manual activation devices are normally placed in the main egress routes from the facility or location. Usually placement in the immediate high hazard location egress route and at the periphery evacuation routes or muster location of the installation is accomplished. 

Many LCDs are based on active-matrix addressing, in which an active device circuit containing one or more TFTs is connected to each pixel. The TFT circuit at each pixel effectively acts as an individual electrical switch that provides the means to store display information on a storage capacitor for the entire frame time, such that the pixel can remain emitting during this entire time rather than for a small fraction of time, as is the case in passive addressing. 

Abstract A new dif active device for light coupling between a planar optical waveguide... 

Analytical balance, equipped with a pneumatic door activation device from Zymark... 

Active devices, while covered under the above rules, are largely covered by rules 9-12 and include the following classes. 

Rule 16 classifies non-active devices specifically intended for recording X-ray diagnostic images as Class Ila, for example. X-ray films. 

Most of the other novel PV technologies suggested so far can be categorized as high-efficiency approaches, which can be divided between approaches that modify and tailor the properties of the active layer to match it better to the solar spectrum versus approaches that modify the incoming solar spectrum and are applied at the periphery of the active device (without fundamentally modifying the active layer properties). 

Stimulated by a variety of commercial applications in fields such as xerography, solar energy conversion, thin-film active devices, and so forth, international interest in this subject area has increased dramatically since these early reports. The absence of long-range order invalidates the use of simplifying concepts such as the Bloch theorem, the counterpart of which has proved elusive for disordered systems. After more than a decade of concentrated research, there remains no example of an amorphous solid for the energy band structure, and the mode of electronic transport is still a subject for continued controversy. 

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