In situ heating

UHV is necessary but not sufficient to ensure an uncontaminated surface. Certainly, the surface will not be contaminated by atoms arriving from the vacuum space, but such contamination as it had before the vacuum was formed has to be removed by bombardment with argon ions. This damages the surface structurally, and that has to be healed by in situ heat treatment. That, however, allows dissolved impurities to diffuse to the surface and cause contamination from below. This problem has to be dealt with by many cycles of bombardment and annealing, until the internal contaminants are exhausted. This is a convincing example of Murphy s Law in action one of the many corollaries of the Law is that new systems generate new problems . 

In situ soil remediation with physical methods includes the in situ heating (in situ thermal treatment), ground-freezing, hydraulic fracturing, immobilization/stabilization, flushing, chemical detoxification, vapor extraction, steam extraction, biodegradation/bioremediation, electroosmosis/ electrokinetic processes, etc. 

Dev, H., Bridges, J.E., and Sresty, G.C., Decontamination of hazardous waste substances from spills and uncontrolled waste sites by radio frequency in situ heating, in Hazardous Material Spills Conference Proceedings, Government Institutes, Rockville, MD, 1984. 

The same concept of volumetric in situ heating by microwaves was also exploited by Larhed and coworkers in the context of scaling-up a biochemical process such as the polymerase chain reaction (PCR) [25], In PCR technology, strict control of temperature in the heating cycles is essential in order not to deactivate the enzymes involved. With classical heating of a milliliter-scale sample, the time required for heat transfer through the wall of the reaction tube and to obtain an even temperature in the whole sample is still substantial. In practice, the slow distribution of heat... 

The allenylsilane ene reaction is also well suited for the synthesis of cyclohexane rings. Jin and Weinreb have described the process of Eq. 13.55 in a synthesis of 5,11-methanomorphanthridine, an Amaryllidaceae alkaloid [64], Conversion of aldehyde 163 to imine 164 with piperonylamine took place in situ. Heating the solution of imine at reflux in mesitylene for 2 h led to cyclization through the conformer shown. The yield of 165 from aldehyde 163 was 66%. 

The Macro porous polymer (MPP) system is an ex situ technology designed to remove hydrocarbon pollutants from process water, groundwater, and wastewater. This technology uses a patented, porous polymer containing an immobilized extraction fluid that assimilates the hydrocarbons into the polymer structure. The particles are regenerated with an in situ heating cycle, and the contaminants are recovered for reuse, recycle, or disposal. 

HeatTrodes can function as in situ heat exchangers to achieve effective warming rates for bioremediation and soil vapor extraction processes. 

Underground coal gasification The production of recoverable and useful combustible gases from the in situ heating of subsurface coal deposits. 

In situ heating of epoxy film adhesives may be accomplished by laminating high-resistance filaments into the film and subsequently applying an electric current. This provides the advantage of a one-component adhesive without the requirements of external heat sources. Once the element is heated, the surrounding material melts, flows, and finally crosslinks. After the adhesive cures, the resistance element that is exterior to the joint is cut off. 

In situ heat treatment is useful for increasing the wear resistance of the finished material... 

FIG. 13.10 Birefringence cycles on freshly prepared p4MAN films. For film a, the linearly polarized light is turned on at t = 0 for 500 s after a 500 s relaxation period, the sample is in situ heated at a rate of 5°C/min to I75°C and then cooled to room temperature. For film b, the sample is cooled rapidly when the maximum birefringence is reached at approximately t = 2200 s as the temperature reached 120 C. Reprinted with permission from reference 41. Copyright 2000 American Chemical Society. 

Prior to placement on feed the catalyst was reduced in situ, heating from room temperature to 515 <>C, under a flow of hydrogen. It was reduced at 515 OC for 8 hours. The temperature was then lowered to 370 OC, and n-heptane was added to the reactor. The reactor was slowly brought to reaction temperature (482 oc) in 3 hours. It should be eu hasized that the catalyst has not been presulfided and no sulfur was added to the n-heptane during the run. On-oil time was started when reactor attained 482 <>C. 

The alkylation reaction of isobutane with a mixture of C4 linear olefins was carried out in liquid phase at temperatures between 25 and 80°C, and at 30 Kg/cm, in a fixed-bed reactor. The space velocity was WHSV = 1 ft referred to the olefins. The isobutane is premixed with the olefins. The molar ratio used in this study was 15. The C4 olefins fraction contains 38% 1-butene, 22% trans-butene, 14% cis-2-butene and 26 % isobutene. In order to analyze the products coming out of the reactor, a ten-loop valve was used to collect the sample to be analyzed after the mn. Products are analyzed by GC, using a 100 m squalane column. Prior to the reaction, catalysts were pretreated in-situ, heating up to 250 C in an air stream. 

Figure 11.7 Chemistry calculated from the XRD QPA of the in situ heating of an SFCA mixture.

DEVELOPMENT OF A RANGE OF BIOLUMINESCENT FOOD BORNE PATHOGENS FOR ASSESSING IN-SITU HEAT INACTIVATION AND RECOVERY OF BACTERIA DURING HEAT TREATMENT OF FOODS... 

Rabiei, A., Thomas, B., Jin, C., Narayan, R., Cuomo, J., Yang, Y., and Ong, J.L. (2006) A study on functionally graded HA coatings processed using ion beam assisted deposition with in situ heat treatment. Surf. Coat. Technol., 200 (20/21), 6111-6116. 

Fig. 7.1. Electron diffraction pattern along the [001] zone, in a tetragonal sample (from the observation of unsplit spots). In situ heating and cooling causes disorder reflected in the presence of diffuse scattering along the basic directions.

The composition of the films depends strongly on the deposition parameters and varies between 0.9-1.3 and 0.3-0.9 for nitrogen and carbon, respectively. Due to the carbon content, the resistivites of these film were quite high, ranging from 550 to 4500 pQ cm. A reduction to 450 pQ cm could be achieved by in situ heat treatment with ammonia. 

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