Typical results

A few examples of the recent results gained by X-ray and neutron scattering/diffraction are detailed in this section. These 

Micro reactor Pt mass ( Z) A/2O3 mass ( Z) Pt loading (wt.-%) Pt dispersion (% Mean Pt cluster size (A) 

Time steps of about 60 s between switching on and off were realized. The performance of the MSE structures depends on their geometry, the electric field strength and the gas pressure. 

Investigations with the modular multi-channel [28,98] and silicon chip [19, 56-62] micro reactors demonstrate that by exact temperature control the oxidation of ammonia can be run with increased and deliberately steered selectivity. A major application is provided by carrying out former high-temperature reactions in the low-temperature regime. In the case of ammonia oxidation in the chip micro reactor, the yield of the value product NO was actually lower in that regime. In the case of the multi-plate-stack micro reactor, higher yields of the value product NO2 were achieved. 

The critical AT and the maximum heat flux are also dependent on the metal used. The data in Fig. 29 for ethanol on three metals at 1 atm. 

Bhow that copper gives the smallest ATei the highest hm ., and the highest 

The usual correlations proposed for the critical temperature difference or for the maximum heat flux do not specify the metal (B5, R12). Obviously this contributes to the observed deviations between the cor. relations and experimental data. Castle s table above indicates how great the deviations may be. 

Effect of type of metal on nucleate boiling. Ethanol was boiled at 1 atm. on polished surfaces (B7). 

Flow perturbation upon continuous (DC) current operation 

Flow perturbation upon alternating (AC) current operation 

The dynamic changes actually lead to the formation of a pulse, which is more or less elongated depending on the frequency [91]. This pulse is followed by a hardly deformed zone so that mixed and unmixed zones are created in an alternating 

Velocity field change upon electric field tuming-on 

Electric potential distribution change upon electric field turning-on 

Ruland and Smarsly [84] study silica/organic nanocomposite films and elucidate their lamellar nanostructure. Eigure 8.47 demonstrates the model fit and the components of the model. The parameters Ipi and (inside H ) account for deviations from the ideal two-phase system. Asr is the absorption factor for the experiment carried out in SRSAXS geometry. In the raw data an upturn at sq is clearly visible. This is no structural feature. Instead, the absorption factor is changing from full to partial illumination of the sample. Eor materials with much stronger lattice distortions one would mainly observe the Porod law, instead - and observe a sharp bend - which are no structural feature, either. 

Eigure 8.48 visualizes the selectivity of this Ruland-Smarsly method for 

Disorder of Nanocomposites and Common Polymers. If one compares the distortion parameters of particular nanocomposites with those of common polymer materials, the relative standard deviations are generally smaller by 1 order of magnitude. More than 30 layers are correlated to each other, whereas the correlation in commercial polymer materials is generally ranging shorter than 4 layers. 

It was seen in the previous section that the developed method enables deposit thickness for several locations on the channel length in conjunction with the permeate flow rate to be measured simultaneously. For a fixed position on the x axis, it is possible in the same time  

The initial permeate flux is 204 Lh m . It decreased rapidly during the first time period (fiom 0 s to 1500 s) and then more slowly to 20 L h m . At the same time, it was possible to measure the cake thickness growth. The final thickness was 55 pm for a total deposited mass of 80gm and a relative flux decrease of 87%. Analysis of the variations of the flux decrease and of thickness growth with time enabled several layers with different structures to be distinguished. The 

The deposit is thicker at the extremities, close to the walls. This could be attributed to wall effects leading to a local increased velocity and subsequently to a higher cake erosion, in the middle of the channel. The thickness profile measurement was compared to the mean thickness measurement. Thus, the integral of the profile curve on the channel width was estimated. A value of 0.162 pm was found which is dose to the value of the integral on the channel width of the mean thickness (0.158 pm ). 

Those results point out some capabilities of the method. First it is possible to follow the changes in the deposit structure with time and to distinguish several kinds of fouling layers. It is also possible to obtain the cross-section of the deposit and to detect wall effects on particle deposition. 

Concentrations of 1 g and 2 g were tested for clay suspensions. In both cases, image processing allowed the determination of a sharp maximum in the light intensity profile and thus the deposit thickness measurement was possible. Higher concentrations will be tested but it currently appears that the LSGI method is well suited to a range of concentrations larger than for other optical techniques. 

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Using the method outlined above, calculations were performed for ten ternary systems. All binary parameters are shown in Table 4. Some typical results are shown in Figures 16 to 19. 

Nowadays this database is composed of about a hundred tests and is continually updated with new tests. The tests are summarized for each case by a description of the vessel, the installation of the sensors used, as well as by a typical result and the conclusions of the control. 

The HILL-SCAN 30XX boards can be used in different PCs. Desktop- and tower-PCs as well suited for laboratory uses. For in-field inspections rugged notebooks and portable PCs are advantageous. A typical portable system is shown in Fig. 2 (USPC 3010), used in MUSE (Mobile Ultrasonic Equipment). This portable PC not only contains the boards for ultrasonic testing but also a controller with power supply for stepper motors, so that a manipulator can be connected directly. The MUSE system is enlarged with a water circulation system which enables a local immersion technique" for in-field inspections. A typical result is shown in Fig. 3, which presents a D-scan of a CFRP- component in RTM-techniques. The defect area caused by an impact is clearly indicated. The manipulator is described in [3]. 

Some fairly typical results, obtained by LaMer and co-workers [275] are shown in Fig. IV-24. At the higher film pressures, the reduction in evaporation rate may be 60-90%—a very substantial effect. Similar results have been reported for the various fatty acids and their esters [276,277]. Films of biological materials may offer little resistance, as is the case for cholesterol [278] and dimyristoylphosphatidylcholine (except if present as a bilayer) [279]. 

Typical results for a semiconducting liquid are illustrated in figure Al.3.29 where the experunental pair correlation and structure factors for silicon are presented. The radial distribution function shows a sharp first peak followed by oscillations. The structure in the radial distribution fiinction reflects some local ordering. The nature and degree of this order depends on the chemical nature of the liquid state. For example, semiconductor liquids are especially interesting in this sense as they are believed to retain covalent bonding characteristics even in the melt. 

Relatively strong adsorbate-adsorbate interactions have a different effect the adsorbates attempt to first optimize the bonding between them, before trying to satisfy their bonding to the substrate. This typically results in close-packed overlayers with an internal periodicity that it is not matched, or at least is poorly matched, to the substrate lattice. One thus finds well ordered overlayers whose periodicity is generally not closely related to the substrate lattice tiiis leads... 

The following are typical results using a lipase cream of average activity ... 

Figure 4 shows a typical result for as a function of temperature for a Fe -containing MnZn-ferrite. changes sign at a certain temperature Tq... 

A AlI lation. 1-Substitution is favored when the indole ring is deprotonated and the reaction medium promotes the nucleophilicity of the resulting indole anion. Conditions which typically result in A/-alkylation are generation of the sodium salt by sodium amide in Hquid ammonia, use of sodium hydride or a similar strong base in /V, /V- dim ethyl form am i de or dimethyl sulfoxide, or the use of phase-transfer conditions. 

A = 4.05 X lO " cm/(s-kPa)(4.1 X 10 cm/(s-atm)) and = 1.3 x 10 cm/s (4)//= 1 mPa-s(=cP), NaCl diffusivity in water = 1.6 x 10 cm /s, and solution density = 1 g/cm . Figure 4 shows typical results of this type of simulation of salt water permeation through an RO membrane. Increasing the Reynolds number in Figure 4a decreases the effect of concentration polarization. The effect of feed flow rate on NaCl rejection is shown in Figure 4b. Because the intrinsic rejection, R = 1 — Cp / defined in terms of the wall concentration, theoretically R should be independent of the Reynolds... 

The special case involving the removal of a low (2—3 mol %) mole fraction impurity at high (>99 mol%) recovery is called purification separation. Purification separation typically results in one product of very high purity. It may or may not be desirable to recover the impurity in the other product. The separation methods appHcable to purification separation include equiUbrium adsorption, molecular sieve adsorption, chemical absorption, and catalytic conversion. Physical absorption is not included in this Hst as this method typically caimot achieve extremely high purities. Table 8 presents a Hst of the gas—vapor separation methods with their corresponding characteristic properties. The considerations for gas—vapor methods are as follows (26—44). 

In early years the contact process frequentiy employed only two or three catalyst stages (passes) to obtain overall SO2 conversions of approximately 95—96%. Later, four pass converters were used to obtain conversions of from 97% to slightiy better than 98%. For sulfur-burning plants, this typically resulted in sulfur dioxide stack emissions of 1500—2000 ppm. 

Many of the by-products of microbial metaboHsm, including organic acids and hydrogen sulfide, are corrosive. These materials can concentrate in the biofilm, causing accelerated metal attack. Corrosion tends to be self-limiting due to the buildup of corrosion reaction products. However, microbes can absorb some of these materials in their metaboHsm, thereby removing them from the anodic or cathodic site. The removal of reaction products, termed depolari tion stimulates further corrosion. Figure 10 shows a typical result of microbial corrosion. The surface exhibits scattered areas of localized corrosion, unrelated to flow pattern. The corrosion appears to spread in a somewhat circular pattern from the site of initial colonization. 

Computations are more difficult for subsequent 2one passes, siace the starting composition of the rod is no longer uniform. Nevertheless, a variety of numerical and analytical results has been obtained for infinite and for finite rods (1,4,12—16). A typical result is shown in Figure 5. Substantial purification can be attained even when k is not significantly different from 1. 

The second front originates in the polymer synthesis community. Efforts are mainly directed toward production of monodisperse block copolymers by living polymerizations. These stmctures typically result in microphase separated systems if one block is a high T material and the other is elastomeric in... 

FIG. 12-44 Typical results of dryer-performance tests. To convert British thermal units per hour-cubic foot-degree Fahrenheit to joules per cubic meter-second-kelvin, multiply by 1.73. 

These differential equations are readily solved, as shown by Luyben (op. cit.), by simple Euler numerical integration, starling from an initial steady state, as determined, e.g., by the McCabe-Thiele method, followed by some prescribed disturbance such as a step change in feed composition. Typical results for the initial steady-state conditions, fixed conditions, controller and hydraulic parameters, and disturbance given in Table 13-32 are listed in Table 13-33. 

The most common impellers are the marine impeller or disc flat-blade turbine the flowpatterns which typically result are illustrated in Fig. 15-22. 

Although each machine has its pecuhar charac teristics and time requirements for various types of grinding, Fig. 20-40 illustrates some typical results obtained under optimum conditions for several materials. 

Typical results from the various types of hazard evaluation techniques. 

Some typical results for the physical properties of common gases which are of indusuial importance are given in Table 3.3. The special position of hydrogen which results from the small mass and size of the H2 molecule should be noted. 

Typical results achieved by application of the DFA technique to date are approximately as follows ... 

In precoating, the prime objective is to prevent the filter medium from fouling. The volume of initial precoat normally applied should be 25 to 50 times greater than that necessary to fill the filter and connecting lines. This amounts to about 5-10 lb/100 fF of filter area, which typically results in a 1/16-in. to 1/8-in. precoat layer over the outer surface of the filter medium. An exception to this rule is in the precoating of continuous rotary drum filters where a 2-in. to 4-in. cake is deposited before filtration. The recommended application method is to mix the precoat material with clear liquor (which may consist of a portion of the filtrate). This mixture should be recycled until all the precoat has been deposited onto the filter medium. The... 

We illustrate some typical results below for electrons and phonons. Closely related results are given elsewhere in this volumc[8,l 1]. 

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