Floating potential

POTENTIAL FLOATING IN FINE POWDERY SEMICONDUCTORS UNDER ILLUMINATION... 

The photoemission of adsorbed xenon (PAX) method, developed by Wandelt to measure local surface potentials with atomic resolution, deserves particular attention. Here, the 5p core levels of adsorbed xenon atoms are used as probes for the local surface potential. The binding energy of these orbitals is measured by photoemission. The method is based on the idea that the Xe core potential floats with the local surface potential. In fact, the 5p binding energy depends on the initial state of the adsorbed neutral Xe atom and the final state of the adsorbed, ionized Xe atom. In a first approximation, both, the polarization of the Xe atom in the initial state and the interaction of the ionized Xe atom with the substrate in the final state... 

Similarly, blocked intake screens caused by aquatic weeds, mussels, or floating debris reduce the heat transfer potential of the condenser. 

The detailed design of the tube bundle must take into account both shell-side and tube-side pressures since these will both affect any potential leakage between the tube bundle and the shell which cannot be tolerated where high purity or uncontaminated materials are required. In general, tube bundles make use of a fixed tubesheet, a floating-head or U-tubes which are shown in Figures 9.62, 9,63 and 9.64 respectively. It may be noted here that the thickness of the fixed tubesheet may be obtained from a relationship of the form ... 

When a probe is inserted into a plasma, it will experience electrons and ions colliding with its tip. Due to the high mean speed of electrons, the flow of electrons is higher than the flow of ions. Consequently, the tip will charge up negatively until the electrons are repelled, and the net current then is zero. The probe potential then is the floating potential, Vfl. The electron current density Je then balances the ion current density 7,. At potentials lower than Vfl the ion current cannot increase further—in fact, only ions are collected from the plasma—and the ion saturation current /,s is measured. The plasma potential Vpi is defined as the potential at which all electrons arriving near the probe are collected and the probe current equals the electron current. Note that the plasma assumes the plasma potential in the absence of a probe hence probe perturbation at Vpi is... 

The open-top floating roof tank design eliminates the potential for BLEVE. Further, the material being handled has no potential for chemical reactions or for condensed-phase explosions. Thus, these types of explosions can also be eliminated from consideration. 

The French drain (also called a channel drain or floating slab) is a construction feature that appears to provoke strong reaction from its defenders and detractors alike. French drains are only a concern in basement foundations. This slab detail is a standard feature in new houses in parts of the country as varied as New York and Colorado, but in other places it is virtually unknown. French drains are used in areas with expansive soils, such as parts of Colorado, to protect the slab from damage if the wall moves. In central New York State, the main function of the French drain is to drain away water that may seep down the walls. One national builder has discontinued and now prohibits the use of French drains in houses because of the potential for radon problems. This builder states that French drains also have been found to significantly increase indoor moisture levels. 

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