Sidewalls

Keywords d rec methods, indirect methods, rock properties, coring, core barrel, standard core analysis, special core analysis, slabbed core, sidewall samples, direct indications, microfossils, sonde, logging unit, invasion, mudcake, formation pressure measurement, fluid sampling, measurement while drilling, formation evaluation while drilling. 

The sidewall sampling tool (Sl/VS) can be used to obtain small plugs (2 cm diameter, 5 cm length, often less) directly from the borehole wall. The tool is run on wireline after the hole has been drilled. Some 20 to 30 individual bullets are fired from each gun (Fig. 5.35) at different depths. The hollow bullet will penetrate the formation and a rock sample will be trapped inside the steel cylinder. By pulling the tool upwards, wires connected to the gun pull the bullet and sample from the borehole wall. 

In a more recent development a new wireline tool has been developed that actually drills a plug out of the borehole wall. With sidewall coring (Fig. 5.36) some the main disadvantages of the SWS tool are mitigated, in particular the crushing of the sample. Up to 20 samples can be individually cut and are stored in a container inside the tool. 

Another design, shown ia Figure 5, functions similarly but all components are iaside the furnace. An internal fan moves air (or a protective atmosphere) down past the heating elements located between the sidewalls and baffle, under the hearth, up past the work and back iato the fan suction. Depending on the specific application, the flow direction may be reversed if a propeUer-type fan is used. This design eliminates floorspace requirements and eliminates added heat losses of the external system but requires careful design to prevent radiant heat transfer to the work. 

These processes are considerably more complex in actual CMOS fabrication. First, the lower layers of a CMOS stmcture typically have a twin-tub design which includes both PMOS and NMOS devices adjacent to each other (see Fig. 3b). After step 1, a mask is opened such that a wide area is implanted to form the -weU, followed by a similar procedure to create the -weU. Isolation between active areas is commonly provided by local oxidation of sihcon (LOCOS), which creates a thick field oxide. A narrow strip of lightly doped drain (LDD) is formed under the edges of the gate to prevent hot-carrier induced instabiUties. Passivation sidewalls are used as etch resists. A complete sequence of fabrication from wafer to packaged unit is shown in Figure 10. 

The most widely used approach to channel flow calculations assumes a steady qua si-one-dimensional flow in the channel core, modified to account for boundary layers on the channel walls. Electrode wall and sidewall boundary layers may be treated differently, and the core flow may contain nonuniformities. 

In order to support the design and fabrication of the prototypical flow train, extensive component testing at the 50 MW level was performed at the CDIF, in addition to testing of electrodes and sidewalls and of coal-fired channels of 20 MW si2e at Textron Defense Systems. 

This process used an all-fluoride electrolyte, a portion of which was frozen on the carbon sidewalls to prevent short circuiting through the wads. One version of the cell operated at 20,000 A and 950—1000°C. The highest purity aluminum produced was 99.98%. A summary of the cell characteristics is given in Table 9. 

Protection Against Flex Cracking. Most antioxidants including waxes provide oxidation protection under static conditions. However, most of them are not effective in mbber products subjected to dynamic flexing, eg, sidewall compounds in tires. The best dynamic protection is provided by either /V-alkyl-/V-phenyl or diaryl-/)-phenylene diamines. 

The steel belt, which provides strength and protection for the ply or pHes, is encased ia a compouad that must possess adhesioa to the steel which provides stress transfer from the very rigid steel to the many times more flexible tread, sidewall, and textile carcass components. The wedge compound is formulated to reduce belt-edge sheer stresses while tying the belt to the carcass and reduciag hysteresis. 

Like HIIR, EPR has a fiiUy saturated backbone and has only unsaturation points available for vulcanization cross-linking in very small percentages of the pendent diene modifier (EPDM). It is an excellent aging compound with high dex fatigue life even when heavily loaded with fillers and is utilized in PCT white sidewalls. 

Tread Sidewall Ply breaker Apex Chafer Bead Liner... 

In tires, carbon black is important because of the high flex fatigue and tear strength requirements of this product. Poor dispersion can result in premature cracking in both treads and sidewalls. In off-the-road tires poor dispersion results in excessive chip/chunk causing a significant loss in treadwear in addition to tread lug cracking which can lead to loss of an entire lug (radial tread bar). 

Clays. Clay, which is generally considered a mild reinforcing filler, is used sparingly in tires. It is most often used in white sidewalls or in low performance tires. Clay toimage in tires worldwide is estimated at 36,000 t annually. Clay can also be coupled to mbber with silanes, and this is the more popular version used in tires. Even with silane coupling, clays are still a weak reinforcing filler compared to both carbon black and siUca. 

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