Sink switching

The iron-based redox cycle depicted in Figure 18.9 provides an effective preconcentrating step for phosphorus by trapping remineralized phosphate in oxic sediments. The conversion of phosphorus from POM to Fe(lll)OOH to CFA is referred to as sink switching. Overall this process acts to convert phosphorus from unstable particulate phases (POM to Fe(lll)OOH) into a stable particulate phase (CFA) that acts to permanently remove bioavailable phosphorus from the ocean. This is pretty important because most of the particulate phosphate delivered to the seafloor is reminer-alized. Without a trapping mechanism, the remineralized phosphate would diffuse back into the bottom waters of the ocean, greatly reducing the burial efficiency of phosphorus. 

An interesting variant to the sink-switching scheme is found in carbonate sediments hosting... 

This sink switching results in enhanced P-retention by sediments. 

Figure 11. Percent of total reactive P in this authigenic phases (filled circles) and in the reducible and organic phases (open circles) for Site 1033. This comparison reveals the sink-switching that occurs during sedimentary P cycling, with the ingrowth of an authigenic P phase and a loss of P from other reactive phases with age and depth.

Fd Isoforms as Source and Sink Switches for Crop Productivity. 129... 

Increased productivity Since root-type Fd was able to perform as a sink switch, its application for enhancing productivity of economical crops would be promising agriculturally. 

The exciter is an AC generator with a stator-mounted field. Direct cur rent for the exciter field is provided from an external source, typically u small variable voltage rectifier mounted at the motor starter. Exciter oui put is converted to DC through a three-phase, full-wave, silicon-diode bridge rectifier. Thyristors (silicon-controlled rectifiers) switch the cur rent to the motor field and the motor-starting, field-discharge resistors These semiconductor elements are mounted on heat sinks and assembled on a drum bolted to the rotor or shaft. 

While some drain cleaners contain concentrated sulfuric acid, many more contain sodium hydroxide. Mixing these two chemicals will not release chlorine gas, but the reaction between them does release a great amount of heat. Someone who makes the mistake of trying to undog their sink with one product and then switches to a different drain cleaner when the first does not clear the drain fast enough could create enough steam to blast the whole corrosive mess out of the sink right into their face. 

Fig. 4. Vertical cross section of a high-temperature Calvet calorimeter (16) cell guides (A) thermal insulation (B) top (C) and bottom (N) electrical heaters thermostat consisting of several metal canisters (D, G, and H) switch (E) electrical heater (F) thermometers (I, J, and K) microcalorimetric element (L) and heat sink (M).

Fig. 5.17 U se of heat sinking or preheating reed switches for soldering or welding can prevent heat stress damage.

Nylon can be sterilised with steam so it is sued in hypodermic syringes and surgical accessories. Curtain runners, sinks, zips, combs and switches are manufactured from nylon. Extruded nylon is used in covering wire ropes, in packaging film for pharmaceuticals, bottles, tubing, etc. Nylon laminates are used for heavy duty driving belts. Monofilaments are used in brushes, sports equipment, surgical sutures, etc. Monofilaments are prepared from nylon 6, 10 or nylon 11. 

Thermoplastics have two properties which make them particularly suited to ultrasonic welding (a) low thermal conductivity and (b) melting or softening temperatures of between 100 and 200 °C. As soon as the ultrasonic power is switched off the substrate or bulk material becomes a heat sink, giving rapid cooling of the welded joint. When more traditional conductive heating is used for welding however the thermal... 

Based on the results of this modeling effort, the global coastal ocean appears to have acted as a net source of CO2 to the atmosphere over the past 300 y due to the combined production of CO2 from biocalcification and an overall state of net heterotrophy. This role is expected to switch to that of a net CO2 sink in response to rising atmospheric CO2 levels and increasing nutrient runoff from land. The latter is stimulating new production and causing an overall state of net autotrophy. Recent observational... 

Ocean has switched from being a small net carbon source to a large sink. 

I glanced at the clock over the kitchen sink. One more piece of toast and it would be time to switch from bathrobe blue to Army green. Still a few minutes left, however, to read the first volunteer s story. It was quite accurate, corresponding closely to what I too had observed. 

To represent the module cooling behavior, it is convenient to define the heat dissipation capability as the ratio of total heat generated to the maximum temperature difference experienced by the switch assembly. This ratio can then be plotted as a fnnction of coolant flow rate to establish the operating range and functional safety margins. Reference [31] shows the heat dissipation capability of the heat sink assembly. 

Note that as the coolant flow rate is increased at lower rates, the capability of the heat sink to remove thermal energy is enhanced. This effect has diminishing retnrns at high rates due to the increased dependency on condnctive rather than convective heat transfer. At low flow rates and at reduced effective heat-transfer coefficients, the resnlts are somewhat impractical. In these cases, adjacent IGBTs are not maintained at equal temperatures. This condition would generate imbalances in the electrical current sharing, resulting in nndesirable switch performance. 

Tellurium—copper alloys are recommended for situations demanding a high production rate with no significant sacrifice in conductivity. These alloys can be soldered, brazed, or welded without incurring embrittlement. They are used in vacuum applications, forgings, screw-machine parts, welding-torch tips, transistor bases, semiconductor heat sinks, electrical connectors (qv), motor and switch parts, and nuts, bolts, and studs. Addition of tellurium significantly improves the surface of machined parts. 

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