Implementing Information Systems: Some Practical Advice and a Richer Model

Recent research suggests that implementing information systems presents considerable difficulties and that many implementations are total or partial failures. This paper argues that what both practitioners and students require are richer and more acceptable models of information systems implementation. Accordingly, case study data concerning the introduction of manufacturing resource planning (MRP II) are used to illustrate five patterns of behaviour (rites) which capture important social actions; and four components of changing psychological orientation. It is argued that appreciation of the rites and psychological developments identified here will support effective change programmes. Guidelines based on our model are provided for practitioners.     

Low-dimensional modelling of dynamics via computer algebra

I describe a method, particularly suitable to implementation by computer algebra, for the derivation of low-dimensional models of dynamical systems. The method is systematic and is based upon centre manifold theory. Computer code for the algorithm is relatively simple, robust and flexible. The method is applied to two examples: one a straightforward pitchwork bifurcation, and one being the dynamics of thin fluid films.     

Hydrolysis of 4-methylumbelliferyl butyrate: A convenient and sensitive fluorescent assay for lipase activity

A rapid, sensitive and convenient fluorescent assay was developed to screen for lipase activity. The non-fluorescent substrate, 4-methylumbelliferyl butyrate (4-MUB), solubilized in either liposomal dispersions or bile salt/lecithin mixed micelles, is hydrolyzed to butyric acid and the highly fluorescent compound, 4-methylumbelliferone (4-MU). Assays are run at 37 C for 10 min, terminated, and the changes in fluorescence quantitated with a Turner III fluorometer. Both lingual and pancreatic lipases exhibit activity against this artificial substrate. The assay has several advantages: nmoles 4 MU/ml/hr are measured allowing the detection of very low lipolytic activity; multiple samples may be simultaneously assayed, and only a brief incubation period is required.     

Simplified characterization of uniaxial and biaxial nonlinearoptical crystals: a plea for standardization of nomenclature andconventions

Standards which eliminate ambiguity in reporting nonlinear phenomena, especially in the increasingly complex realm of biaxial crystals, are proposed. In order to restore uniformity to the designation of crystallographic axes and crystal tensor properties, adoption of IEEE/ANSI Std. 176, with a small but much needed modification for crystal class mm2, is recommended. For the reporting of nonlinear interaction characteristics, other frames are proposed which result in simpler rules than heretofore given for categorizing phase-matching loci, and for characterizing eigenmode polarizations, double refraction, effective nonlinear coupling, and first- and second-order acceptance bandwidths (angular, spectral, thermal) along these loci. Similarities as well as differences between biaxial and uniaxial crystals are emphasized     

Deuterated liquid scintillator (NE230) as a fast neutron detectorfor cold-fusion and other research

Deuterated scintillators (NE230) can provide, without time-of-flight, usable neutron energy spectra for neutrons E _n⩾1 MeV. The authors have assembled and calibrated several of these detectors and used them in experiments searching for d+d fusion-neutron emission (E_n, 2.5 MeV) in Pd+D ₂O electrolysis and Ti+D₂ adsorption at LN temperatures. The detectors yielded direct fusion-neutron spectra and set limits in the Pd+D and Ti+D experiments of <7×10^-24 fusion n/s/dd pair and <3×10^-24 fusion n/s/dd pair respectively. In addition, these detectors have been used for in-beam accelerator experiments requiring coincidence between fast neutrons and scattered ions