Distribution pulse

D. Spatially Distributed Pulsed Gradient Spin-Echo NMR Using Single-Wire Proximity... 

Callaghan, P. T., and Stepisnik, J. (1995b). Spatially-distributed pulsed gradient spin echo NMR using single-wire proximity. Phys. Rev. Lett. 75, 4532-4535. 

The model in Fig 14-14b is PFR and CSTR in parallel. The exit age distribution for the eSTR is a negative gradient curve, intcmipted by the distinct exit age distribution pulse of the PFR. The CSTR will always provide a fraction of eflluenc which has been inside the reactor for less than time t, which incicases with time. But when (he effluent exits the PFR at a specified time after zero, this increased effluent is superimposed upon F9t) of the CSTR. giving a combined F(t). 

Pulsed sources can be used to tailor the material s internal temperature distribution. Pulsing is typically used to sharpen spatial temperature gradients. Solutions to Eq. 18.9 involving a single pulse for Pe = 0, p = 1 have been obtained by a number of researchers, and consideration of the general case of pulsed irradiation of a moving material with elliptical Gaussian beams is presented by Sanders [27],... 

The detector signal is a train of randomly distributed pulses corresponding to the detection of the individual photons. There are many signal periods without photons other signal periods contain one photon pulse. Periods with more than one photon are very rare. When a photon is detected, the time of the corresponding detector pulse in the signal period is measured. The events are collected in a memory by adding a T in a memory location with an address proportional to the detection time. After many photons, the distribution of the detection times, i.e. the waveform of the optical pulse, builds up in the memory. 

The upper limit of the counting rate depends on the time resolution of the discriminator, which may be below 10 ns. This allows counting of randomly distributed pulse rates up to about 10 MHz without essential counting errors. 

Introduction Electric Power Distribution Pulsed Power... 

Iwankiewicz R, Nielsen SRK, Thoft-Christensen P (1990) Dynamic response of non-linear systems to Poisson-distributed pulse trains Markov approach. Struct Saf 8 223-238... 

In the previous section we discussed light and matter at equilibrium in a two-level quantum system. For the remainder of this section we will be interested in light and matter which are not at equilibrium. In particular, laser light is completely different from the thennal radiation described at the end of the previous section. In the first place, only one, or a small number of states of the field are occupied, in contrast with the Planck distribution of occupation numbers in thennal radiation. Second, the field state can have a precise phase-, in thennal radiation this phase is assumed to be random. If multiple field states are occupied in a laser they can have a precise phase relationship, something which is achieved in lasers by a teclmique called mode-locking Multiple frequencies with a precise phase relation give rise to laser pulses in time. Nanosecond experiments... 

Figure Al.6.30. (a) Two pulse sequence used in the Tannor-Rice pump-dump scheme, (b) The Husuni time-frequency distribution corresponding to the two pump sequence in (a), constmcted by taking the overlap of the pulse sequence with a two-parameter family of Gaussians, characterized by different centres in time and carrier frequency, and plotting the overlap as a fiinction of these two parameters. Note that the Husimi distribution allows one to visualize both the time delay and the frequency offset of pump and dump simultaneously (after [52a]).

FigureBl.5.16 Rotational relaxation of Coumarin 314 molecules at the air/water interface. The change in the SFI signal is recorded as a fimction of the time delay between the pump and probe pulses. Anisotropy in the orientational distribution is created by linearly polarized pump radiation in two orthogonal directions in the surface. (After [90].)...

Figure Bl.12.2. Power distribution for an RF pulse of duration applied at frequency v...

Figure Bl.14.6. J -maps of a sandstone reservoir eore whieh was soaked in brine, (a), (b) and (e), (d) represent two different positions in the eore. For J -eontrast a saturation pulse train was applied before a standard spin-eeho imaging pulse sequenee. A full -relaxation reeovery eiirve for eaeh voxel was obtained by inerementing the delay between pulse train and imaging sequenee. M - ((a) and (e)) and r -maps ((b) and (d)) were ealeulated from stretehed exponentials whieh are fitted to the magnetization reeovery eurves. The maps show the layered stnieture of the sample. Presumably -relaxation varies spatially due to inliomogeneous size distribution as well as surfaee relaxivity of the pores. (From [21].)...

Figure Bl.14.9. Imaging pulse sequence including flow and/or diflfiision encoding. Gradient pulses before and after the inversion pulse are supplemented in any of the spatial dimensions of the standard spin-echo imaging sequence. Motion weighting is achieved by switching a strong gradient pulse pair G, (see solid black line). The steady-state distribution of flow (coherent motion) as well as diffusion (spatially...

In TOF-SARS [9], a low-keV, monoenergetic, mass-selected, pulsed noble gas ion beam is focused onto a sample surface. The velocity distributions of scattered and recoiled particles are measured by standard TOF methods. A chaimel electron multiplier is used to detect fast (>800 eV) neutrals and ions. This type of detector has a small acceptance solid angle. A fixed angle is used between the pulsed ion beam and detector directions with respect to the sample as shown in figure Bl.23.4. The sample has to be rotated to measure ion scattering... 

Consequently, the reaction yield F in figure B2.5.15 is shown as a fiinction of the fluence, F. At the end of a laser-pulse sequence with a typical fluence F 3 J cm, practically 100% of the CF I is photolysed. As described in section B2.5.4.3. the product-level distribution of the iodine atoms fonned in this type of reaction can be detemiined... 

With broad-band pulses, pumping and probing processes become more complicated. With a broad-bandwidth pulse it is easy to drive fundamental and overtone transitions simultaneously, generating a complicated population distribution which depends on details of pulse stmcture [75], Broad-band probe pulses may be unable to distinguish between fundamental and overtone transitions. For example in IR-Raman experiments with broad-band probe pulses, excitation of the first overtone of a transition appears as a fundamental excitation with twice the intensity, and excitation of a combination band Q -t or appears as excitation of the two fundamentals 1761. 

Pulsed Columns. The efficiency of sieve-plate or packed columns is increased by the appHcation of sinusoidal pulsation to the contents of the column. The weU-distributed turbulence promotes dispersion and mass transfer while tending to reduce axial dispersion in comparison with the unpulsed column. This leads to a substantial reduction in HETS or HTU values. 

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