A 7-year follow-up of sacral anterior root stimulation for bladder control in patients with a spinal cord injury: quality of life and users' experiences\ud

Study design: Cross-sectional descriptive study.\ud \ud Objectives: To assess long-term effects and quality of life (QoL) of using sacral anterior root stimulation (SARS) in spinal cord injured patients.\ud \ud Setting: Neurosurgical and Urological Departments of a large teaching hospital and a large rehabilitation centre in the Netherlands.\ud \ud Methods: In all, 42 patients with complete spinal cord injury (SCI) implanted between 1987 and 2000 were included. A questionnaire was constructed to determine complications, technical failures and personal experiences of the patients. The Qualiveen questionnaire was used and the outcome was compared with data obtained from a reference group of 400 SCI patients with neurogenic bladder problems not using the bladder controller. The Qualiveen questionnaire measures disease-specific aspects in four domains with respect to limitations, constraints, fears and feelings and general QoL aspects, suitable for use in SCI patients with urinary disorders.\ud \ud Results: The results of 37 patients are presented. Our results with the bladder controller with respect to medical and technical complications and infection rates are similar to the results presented by others. From users' experiences, the most important advantages reported were a decreased infection rate (68%), improved social life (54%) and continence (54%). Comparison of the obtained results of our patient group with the Qualiveen questionnaire with a reference group not using the bladder controller indicates that the specific impact of urinary disorders in the four domains on QoL is reduced and that general QoL is improved.\ud \ud Conclusion: SARS is effective and safe for neurogenic bladder management in patients with complete SCI. Users' experiences are positive. Furthermore, this therapy seems to reduce the effects of urinary-disorder-specific QoL aspects, and to increase the QoL in general\u

EDITAR: a module for reaction rate editing and cross-section averaging within the AUS neutronics code system.

The EDITAR module of the AUS neutronics code system edits one and two-dimensional flux data pools produced by other AUS modules to form reaction rates for materials and their constituent nuclides and to average cross sections over space and energy. The module includes a Bsub(L) flux calculation for application to cell leakage. The STATUS data pool of the AUS system is used to enable the 'unsmearing' of fluxes and nuclide editing with minimal user input. The module distinguishes between neutron and photon groups and printed reaction rates are formed accordingly. Bilinear weighting may be used to obtain material reactivity worths and to average cross sections. Bilinear weighting is at present restricted to diffusion theory leakage estimates made using mesh-average fluxes

Comparison of neutron resonance absorption in thermal reactor lattices in the AUS neutronics code system with Monte Carlo calculations.

The calculation of resonance shielding by the subgroup method as incorporated in the MIRANDA module of the AUS neutronics code system is compared with Monte Carlo calculatons for a number of thermal reactor lattices. For the large range of single rod and rod cluster lattices considered AUS results for resonance absorption were high by up to two per cent

MIRANDA - module based on multiregion resonance theory for generating cross sections within the AUS neutronics code system.

MIRANDA is the cross-section generation module of the AUS neutronics code system used to prepare multigroup cross-section data which are pertinent to a particular study from a general purpose multigroup library of cross sections. Libraries have been prepared from ENDF/B which are suitable for thermal and fast fission reactors and for fusion blanket studies. The libraries include temperature dependent data resonance cross sections represented by subgroup parameters and may contain photon as well as neutron data. The MIRANDA module includes a multiregion resonance calculation in slab cylinder or cluster geometry a homogeneous B sub L flux solution and a group condensation facility. This report documents the modifications to an earlier version of MIRANDA and provides a complete user's manual

CHAR and BURNMAC - burnup modules of the AUS neutronics code system.

In the AUS neutronics code system the burnup module CHAR solves the nuclide depletion equations by an analytic technique in a number of spatial zones. CHAR is usually used as one component of a lattice burnup calculation but contains features which also make it suitable for some global burnup calculations. BURNMAC is a simple accounting module based on the assumption that cross sections for a rector zone depend only on irradiation. BURNMAC is used as one component of a global calculation in which burnup is achieved by interpolation in the cross sections produced from a previous lattice calculation

Extension of the AUS reactor neutronics system for application to fusion blanket neutronics.

The AUS modular code scheme for reactor neutronics computations has been extended to apply to fusion blanket neutronics. A new group cross-section library with 200 neutron groups 37 photon groups and kerma factor data has been generated from ENDF/B-IV. The library includes neutron resonance subgroup parameters and temperature-dependent data for thermal neutron scattering matrices. The validity of the overall calculation system for fusion applications has been checked by comparison with a number of published conceptual design studies

ICPP - a collision probability module for the AUS neutronics code system.

The isotropic collision probability program (ICPP) is a module of the AUS neutronics code system which calculates first flight collision probabilities for neutrons in one-dimensional geometries and in clusters of rods. Neutron sources including scattering are assumed to be isotropic and to be spatially flat within each mesh interval. The module solves the multigroup collision probability equations for eigenvalue or fixed source problems

Neutronics study of reduced enrichment fuel for the HIFAR research reactor.

The neutronics consequences of using lower enrichment fuels for the research reactor HIFAR have been assessed. Comparative results include neutron flux reactivity performance plutonium production and a selection of reactivity coefficients and safety-related parameters for both high and low burn-up of the fuels considered

MCRP - a Monte Carlo resonance program for neutrons slowing down in single rod and rod cluster lattices.

MCRP is a Monte Carlo computer program for tracking neutrons slowing down in single rod and rod cluster lattices. The code is intended for calculations of resonance absorption in reactor fuel nuclides using cross sections at 124 000 energy points below 20 keV. The only intrinsic assumptions are that scattering is both elastic and isotropic in the centre of mass system

A Computational Comparison of Optimization Methods for the Golomb Ruler Problem

The Golomb ruler problem is defined as follows: Given a positive integer n, locate n marks on a ruler such that the distance between any two distinct pair of marks are different from each other and the total length of the ruler is minimized. The Golomb ruler problem has applications in information theory, astronomy and communications, and it can be seen as a challenge for combinatorial optimization algorithms. Although constructing high quality rulers is well-studied, proving optimality is a far more challenging task. In this paper, we provide a computational comparison of different optimization paradigms, each using a different model (linear integer, constraint programming and quadratic integer) to certify that a given Golomb ruler is optimal. We propose several enhancements to improve the computational performance of each method by exploring bound tightening, valid inequalities, cutting planes and branching strategies. We conclude that a certain quadratic integer programming model solved through a Benders decomposition and strengthened by two types of valid inequalities performs the best in terms of solution time for small-sized Golomb ruler problem instances. On the other hand, a constraint programming model improved by range reduction and a particular branching strategy could have more potential to solve larger size instances due to its promising parallelization features