The Role of Final State Interactions in Quasielastic 56^{56}Fe(e,e′)(e,e') Reactions at large ∣q⃗∣|\vec q|

A relativistic finite nucleus calculation using a Dirac optical potential is used to investigate the importance of final state interactions [FSI] at large momentum transfers in inclusive quasielastic electronuclear reactions. The optical potential is derived from first-order multiple scattering theory and then is used to calculate the FSI in a nonspectral Green's function doorway approach. At intermediate momentum transfers excellent predictions of the quasielastic $^{56}$Fe$(e,e')$ experimental data for the longitudinal response function are obtained. In comparisons with recent measurements at $|{\vec q|}=1.14$~GeV/c the theoretical calculations of $R_L$ give good agreement for the quasielastic peak shape and amplitude, but place the position of the peak at an energy transfer of about $40$~MeV higher than the data.Comment: 13 pages typeset using revtex 3.0 with 6 postscript figures in accompanying uuencoded file; submitted to Phys. Rev.

Full-Folding Optical Potentials for Elastic Nucleon-Nucleus Scattering based on Realistic Densities

Optical model potentials for elastic nucleon nucleus scattering are calculated for a number of target nuclides from a full-folding integral of two different realistic target density matrices together with full off-shell nucleon-nucleon t-matrices derived from two different Bonn meson exchange models. Elastic proton and neutron scattering observables calculated from these full-folding optical potentials are compared to those obtained from `optimum factorized' approximations in the energy regime between 65 and 400 MeV projectile energy. The optimum factorized form is found to provide a good approximation to elastic scattering observables obtained from the full-folding optical potentials, although the potentials differ somewhat in the structure of their nonlocality.Comment: 21 pages, LaTeX, 17 postscript figure

A Temporal Expert System for Engineering Design Change Workflow

Workflow management, which is concerned with the coordination and control of business processes using information technology, has grown from its origins in document routing to include the automation of process logic in business process engineering. Workflow also has a strong temporal aspect. Activity sequencing, deadlines, routing conditions,and scheduling all involve the element of time. Temporal expert systems, which use knowledge-based constructs to represent and reason about time, can be used to enhance the capabilities of workflow software. This paper presents a temporal expert system workflow component for tracking engineering design changes. We use Allen\u27s theory of temporal intervals in our model to enhance the decision-making, timing, and routing activities in a workflow application. We test the model using information from a real-world engineering design situation and suggest further research opportunitie

Energy Dependence of the NN t-matrix in the Optical Potential for Elastic Nucleon-Nucleus Scattering

The influence of the energy dependence of the free NN t-matrix on the optical potential of nucleon-nucleus elastic scattering is investigated within the context of a full-folding model based on the impulse approximation. The treatment of the pole structure of the NN t-matrix, which has to be taken into account when integrating to negative energies is described in detail. We calculate proton-nucleus elastic scattering observables for $^{16}$O, $^{40}$Ca, and $^{208}$Pb between 65 and 200 MeV laboratory energy and study the effect of the energy dependence of the NN t-matrix. We compare this result with experiment and with calculations where the center-of-mass energy of the NN t-matrix is fixed at half the projectile energy. It is found that around 200 MeV the fixed energy approximation is a very good representation of the full calculation, however deviations occur when going to lower energies (65 MeV).Comment: 11 pages (revtex), 6 postscript figure

An Acoustic Technique for the Noninvasive in-Situ Measurement of Crystal Size and Solution Concentration

We demonstrated the use of acoustic measurements for tracking potassium dihydrogen phosphate (KDP) crystal growth. Both KDP solution concentration and KDP crystal size can be found by using information derived from acoustic wave propagation in the solution. Acoustic measurements show good correlation to conductivity measurements for KDP solution concentration

Irrigation demand model

Presented at the 2002 USCID/EWRI conference, Energy, climate, environment and water - issues and opportunities for irrigation and drainage on July 9-12 in San Luis Obispo, California.Includes bibliographical references.Like many jurisdictions in North America, the irrigation industry in Alberta, Canada has found it necessary to intensively examine its future state of development, in view of substantially increased competition for a finite supply of available water. In order to do so, it was recognized that available technical science and assessment tools needed to be up-dated and expanded. Specifically, the opportunity and ability to utilize state-of-the-art computer modelling techniques could allow much more detailed and varied analyses to be carried out. As part of a broad scope basin water management planning review, the development of a complex irrigation demand model was undertaken. After several years of detailed and intensive software development, a suite of data input, irrigation simulation and analysis tools has been derived. The application of the irrigation demand model component provides for very detailed projections of daily water requirements, consumptive use, conveyance and application losses, as well as return flows. Annual and multi-year irrigation demands can be determined in conjunction with water supply conditions that reflect both the interrelationship with the vagaries of climate as well as varying scenarios of development within the industry. In particular, output from the application of the whole suite of tools indicates both the projected level of water supply deficits as well as the potential impacts of those shortages

Model-Based Signal Processing for Laser Ultrasonic Signal Enhancement

The use of laser-based ultrasonics in the testing of materials and structures offers various advantages over more traditional ultrasonic methods, but is often less sensitive when applied to real materials. Although high energy laser pulses can generate large ultrasonic displacements, nondestructive evaluation requires that the ablation regime be avoided, thus limiting the amount of optical energy which may be used. For this reason, signal processing of laser generated ultrasonic waveforms detected using laser interferometers may be required to extract the desired information from a nondestructive laser ultrasonic test. A model-based signal processing technique offers a way to enhance the signal-to-noise ratios significantly for ultrasonic waveforms obtained using laser-based systems with the generation of the ultrasound occurring in the nondestructive thermoelastic regime

Sensitivities of the Proton-Nucleus Elastical Scattering Observables of 6He and 8He at Intermediate Energies

We investigate the use of proton-nucleus elastic scattering experiments using secondary beams of 6He and 8He to determine the physical structure of these nuclei. The sensitivity of these experiments to nuclear structure is examined by using four different nuclear structure models with different spatial features using a full-folding optical potential model. The results show that elastic scattering at intermediate energies (<100 MeV per nucleon) is not a good constraint to be used to determine features of structure. Therefore researchers should look elsewhere to put constraints on the ground state wave function of the 6He and 8He nuclei.Comment: To be published in Phys. Rev.