Neutron Probes

Field methods of measuring soil water are primarily designed to measure water in the range of -10 to -1500 kPa of pressure. However, different instruments have different ranges as shown in Table 5.1. Tensiometers, porous blocks, and thermocouple psychrometers are usually installed in the field and measurements are taken on a regular basis. Neutron probe and time domain reflectometry (TDR) equipment are usually carried to the field each time a... 

Neutron probe 0 to <-1,500 Cannot be used in high organic soils... 

Figure 8.2. Neutron probe for determining soil moisture, where nf is fast neutrons and ns is slow neutrons.

E. Rhodes, C. E. Dickerman, C. W. Peters, Associated-Particle Sealed-Tube Neutron Probe for Characterization of Materials, ANL/B-E/CP-78949, Active Probe Technologies Conference on International Symposium on Substance Identification Technologies, 4—8 October 1993, Innsbruck, Austria. 

Prask, H.Jr Neutron Probes Tackle Industrial Problems. Advanced Materials Processes, 26 (September 1991). 

Thus neutrons probe the dynamics of density fluctuations. The properties pk(0 can be regarded as collective coordinates. 

Franchet-Beuzit J, Spotheim-Maurizot M, Sabattier R, Blazy-Baudras B, Charlier M (1993) Radiolytic footprint. (1 rays, y photons, and fast neutrons probe DNA-protein interactions. Biochemistry 32 2104-2110... 

A flow-through alpha detector in the column effluent line is used to monitor the progress of an elution, and a movable neutron probe is used to determine the location of the 252Cf... 

Monitoring of the 232Cf band movement with the neutron probe (Fig. 3) provides advance information on when to expect einsteinium in the eluate and can be used as a backup indicator for changing effluent collection bottles during the einsteinium-californium elution if the alpha detector fails. Also/ the neutron probe can be used to detect problems such as insufficient resin in the columns or incomplete elution from the loading column. 

Figure 3. Movement of the 252Cf peak as measured by the neutron probe during a typical run to separate transplutonium elements...

The used resin from each column may contain a small amount of actinides that failed to elute. The amount is estimated by counting fast neutrons from 2 2Cf with the in-cell neutron probe. The 252Cf content of the resin, usually <100 pg of 252Cf, can be recovered by leaching with strong HNC. After acid leaching several batches of resin have been calcined in an electric resistance furnace and the ashes leached with HNO3 however, very little additional 2 2cf was recovered. 

We now introduce a set of preferred coordinates ), cf Refs. [Kiibler 1973 Zeh 1973 Zurek 1981 Zurek 1982 Zurek 2003], These are the relevant degrees of freedom coupled to the neutron probe. The density matrix needed in (13) is then the reduced one in the space spanned by these states, and it is obtained by tracing out the (huge number of the) remaining degrees of freedom belonging to the "environment" of the microscopic scattering system (e.g., a proton and its adjacent particles). To simplify notations, we denote this reduced density matrix by p too. 

Eqs. (2) and (3) stand, respectively, for bilinear and linear probe-system coupling. For optical probes (2) and (3) correspond to Raman and single-photon scattering, respectively. For atom or neutron probes (2) is appropriate. 

Neutron probe assembly consisting of probe, detector, scalar (cormting device) and cable (Fig. 2.7)... 

Fig. 2.8. A schematic representation of a typical calibration curve for measuring soil water content by neutron probe method.

Soil water content and soil water potential were measured with a neutron probe and tensiometers. Plant water potential was measured... 

The sludge concentration in the trickling filter is assessed by a neutron probe and determines how often the bed will be cleaned or whether to modify the throughput rate (load limits of 800 to 1000 kg of sludge per cubic meter of bed). 

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