Water targets

Mixer 6 undefined mixture in region II B5 = water (target product) M6 = mixture in region III... 

Figure 24.16 Cooling water targets limited by constraints on the return temperature.

In concentration interval (200 100 ppm), only process 1 exists, Fig. 12.3. Targeting in this concentration interval is shown in Fig. 12.6. The total amount of water required is 100 t at a concentration of 200 ppm. Since 102.5 t of water at a concentration of 200 ppm is available for reuse from the previous interval, no fresh water is required in this interval. This eventually sets 200 ppm as the pinch concentration, i.e. the concentration beyond which the water target does not change. The total amount of wastewater generated from processes is 102.5 t, which is the minimum wastewater target. 

The fresh water target for the first sequence of this system of batch processes is, therefore, 1560 kg. This target is exactly the same as that obtained in Section 12.2.2 when time was taken as the primary constraints. 

All targets in these tests were secured to a post located in 4 ft of water. Targets were suspended from the post by a rope so that the targets were approximately 1 ft from the seafloor. For initial tests, a target was constructed using a commercially available TNT simulant. The simulant consists of TNT coated onto particles of sand, but the quantity of TNT in the simulant is insufficient to sustain a detonation. This target was placed inside a water-permeable fabric bag and was affixed to the pole as previously described. 

E.J. Knust, M.J. Machulla, M. Molls, F-production in a water target with high yields for F-labelling of organic compounds Synthesis of 6-C F]nicotinic acid diethylamide, J. Label. Compds Radiopharm. 19 (1982) 1643-1644. 

E. J. Knust, H.J. Machulla, C. Astfalk, Radiopharmaceuticals V F-Labeling with water target produced fluorine-18—Synthesis and quality control of 6- F-nicotinic acid diethylamide, Radiochem. Radioanal. Lett. 55 (1983) 249-255. 

F was produced by irradiating H2160 water target in a cyclotron in the 160(3Fle, p)18F nuclear reaction. 

Treatment Chemicals treating cone. (mol/L water) Target WPG (%)... 

The —CHj— group has a 5p contribution of -.328, and 5 contribution of -.512. The slope of the —CH2— group vector in the interactive design space is. 64. This is very close to the acetic acid-water target line slope of. 49. Adding several —CH2— groups to any of the solvents shown in Table XVIII thus results in an acceptable new solvent. 

Materia1 for Drying Initial Water (%) Target Final Moisture <%) Increased Throughput Due to Ultrasound... 

Fluorine-18 (q/2 = 110 min) is produced by irradiation of lsO-water with 10-18 MeV protons in a cyclotron and recovered as 18F-sodium fluoride by passing the irradiated water target mixture through a carbonate type anion exchange resin column. The water passes through, whereas 18F is retained... 

Nishiizumi K, Finkel RC, Klein J, Kohl CP (1996) Cosmogenic production of Be and °Be in water targets. J Geophys Res 101 22225-22232... 

For many kinds of research prepared directly in water targets... 

N-Nitrite. The NOs prepared in any of the water targets described above can be quantitatively reduced to using a copperized... 

Chemical reduction of labeled oxides of nitrogen formed in water targets provide a relatively simple s)mthesis for NHs. The reduction reaction can be followed immediately by a micro-Keldahl distillation to purify and to concentrate the volatile Two reductants have been... 

N-Nitrogen can also be prepared from water targets irradiated with protons. The from a water target has been used to prepare... 

Parks and Krohn (16) used a recirculating water target for the production of NOs" and used chemical methods subsequently to produce N02" and NHs. Lindner et al. (20) also used a recirculating water target and collected NOg", N02", and NH4 during bombardment by means of a mixed-bed ion-exchange column in a side loop. The column was subsequently eluted to yield 10-30% and 90-70% NOs" +... 

Large-sized liquid targets are not common, mainly on account of hydrolysis and radiation chemical effects. In contrast, small-sized water targets for production of and have attracted considerable attention. Molten salt and flowing-loop liquid targets have found only limited application. 

The radionuclides and F are commonly produced using water targets, and several types of water targets have been developed, particularly for F production(for reviews cf. Qaim et al. 1993 Schlyer 2003). A typical pressurized water target for medium-scale production is shown in Fig. 39.7. It consists of a titanium body, electron-beam welded to two titanium foils (75 pm thick), which act as front and back windows. The target takes 1.3 ml of water with no expansion space and the thickness of the water filling amounts to 3.5 mm. During irradiation, the back window is water-cooled, typically to 8-10°C, and the front window is helium-cooled to -7°C. It withstands pressures of up to 7 bar and proton beam currents of up to 20 pA. A polyethylene-polypropylene copolymer tube with an i.d. of 0.8 mm and a He drive pressure of 1.3 bar is considered a reliable transfer system. 

Typical medium pressure water target system for production of and (after Qaim et al. 1993)... 

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