Polar chart

Step 1 Plot data on the polar chart (Figure J-1). Scale the chart so the largest and smallest amplitude will fit conveniently. 

You now have a correlation between the units on the polar chart and the g in of actual balance. 

The circle you have drawn must contain the origin of the polar chart. If it doesn t, the residual unbalance of the rotor exceeds the applied test unbalance. 

NOTE Several possibilities for the drawn circle not including the origin of the polar chart are operator error during balancing, a faulty balancing machine pickup or cable, or the balancing machine is not sensitive enough. 

If the circle does contain the origin of the polar chart, the distance between origin of the chart and the center of your circle is the actual residual unbalance present on the rotor correction plane. Measure the distance in units of scale you choose in Step 1 and multiply this number by the scale factor determined in Step 6. Distance in units of scale between origin and center of the circle times scale factor equals actual residual unbalance. 

Relative elution solvent strength (or eluotropic strength) is depicted in solvent polarity charts (Figure 2.39). The relative elution strength for a solvent on a polar, normal-phase sorbent such as silica or alumina increases in reverse order to that measured on a nonpolar, reversed-phase sorbent. Ac-... 

Figure 2.39. Solvent polarity chart indicates relative elution strength. (Reprinted with permission from Ref. 116. Copyright > 2002 Alltech Associates.)...

Fig. 2 Polar display and strip chart diqilay windows.

With polarizers fidly crossed and the specimen rotated to maximum brightness, the sample thickness is determined with the aid of a calibrated eyepiece micrometer, and the polarization (retardation) color is noted. From these the birefringence may be determined mathematically or graphically with the aid of a Michel-L vy chart. 

A few comments on the polar effects of the substituents reported in Tables IX—XI are now relevant. With the exception of 4-chloro-5-nitroquinoline (see Section IV, C, l,c), they involve only positions not subject to primary steric effects. The relations to the reaction center are of the conjugative cata, amphi) as well as of the non-conjugative class meta, epi, pros) as shown in Chart 3 by structures 45 and 46. 

Figure 4.27 Flow chart for coluwi selection based on sample type (m - molecular weight). PLC precipitation-liquid chromatography SEC = size-exclusion chromatography lEC - ion-exchange chromatography HIC hydrophobic interaction chromatography LSC liquid-solid chromatography RPC - reversed-phase liquid chromatography BPC (polar) bonded-phase chromatography and IPC - ion-pair chromatography.

SPE is a useful device for working up of polymer additive dissolutions the apolar polymer is retained on the Cj 8 sorbent, while analytes may be eluted. In the fractionation of dissolutions it is advantageous to make use of the differences in polarity and affinity of the components with the sorbent. SPE of applied samples may be done with cartridges or disks, either off- or on-line. A flow-chart for the use of SPE has been published [3], Applications of SPE have been described in several monographs [511,512]. 

Choose a solvent to develop the plate. You let this solvent (eluent) pass through the adsorbant by capillary action. Nonpolar eluents (solvents) will force nonpolar compounds to the top of the plate, whereas polar eluents will force BOTH polar andnonpolar materials up the plate. There is only one way to choose eluents. Educated guesswork. Use the chart of eluents in Chapter 18. 

Whereas poly(9,9-dihexylfluorene) (PDHF, 195) is generally considered as amorphous, PF with longer octyl side chains, PFO 196, is crystalline material. Many PFs — dioctyl (PFO 196 [228,230,231]) or 2-ethyl hexyl) (197 [232]) as well as some fluorene copolymers [233] exhibit liquid crystalline behavior, opening a possibility to fabricate polarized LEDs [224,234,235] (Chart 2.45). 

In addition to 195-200, many other alkyl substituents and their derivatives have been introduced at position 9 of the fluorene nucleus in order to create a processible stable blue-emitting PF material, e.g., 203a-h [273-275,305], Chiral-substituted PFs 200 and 203g,h have been synthesized to study their chiroptical properties [306], particularly interesting due to polarized emission in such materials (see Chapter 5 in this book) (Chart 2.47). 

Dow Chemicals group and coworkers [276,350] synthesized similar triarylamine-fluorene copolymers 251 and 252, possessing carboxylic acid substituents, via hydrolysis of the corresponding ethyl ester polymers, prepared by Suzuki polymerization. Due to the very polar substituents, the copolymers 251 and 252 are only soluble in polar solvents such as DMF but not in aromatic hydrocarbons as toluene or xylene, which allowed simple fabrication of multilayer PLEDs by solution processes (Chart 2.65). 

A series of fluorene copolymers with amino-functionalized side chains 373 and 374 has been prepared by the same group (Chart 2.92). Upon quaternization, they gave copolymers 375 and 376, which were soluble in polar solvents (methanol, DMF, DMSO) [439]. Devices from the... 

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