The science-industry interface: Correlation of time series of indicators and their spectra,and growth models in the nuclear fuels industry

This paper is the third in a series on the flows of influence at the interface between geoscience research and the exploration for and mining of nuclear fuels. It deals with the application of signal processing methods to research and industry indicators, with emphasis on time and frequency domain correlations and lags, and on growth modelling of the indicators using the special and general logistic models. The findings include the following: there was a strong interchange across the science-industry interface; quantitative methods can establish the degree of correlation and the time periods in which these correlations mainly reside; also the timing of decisions to initiate exploration and research can be specified in this case. A strategy of applying quantitative methods, history of science, and periodic analyses of the state of the industry to studies of science policy is suggested by this research.     

A comparison of leaf-spring with aircushion trailer suspensions in the transport environment

Packaging engineers need to be able to accurately determine the forces present in the shipping environment in order to protect packaged goods. The purpose of this study was to determine the vertical vibration levels measured in three separate truck-trailer suspension systems; conventional leaf-spring, conventional air-ride and damaged air-ride. The main conclusion reached in this study is that the air-ride suspension when maintained gives lower power density (PD) levels on all road surfaces studied. A damaged air-ride suspension and leaf-spring suspension are very similar in response frequencies, although the damaged air-ride produces higher vibration levels at lower frequencies.     

Base alumina ceramics with dispersoids: mechanical behaviour and tissue response afterin vivo implantation

Base alumina ceramics with dispersoids (BAC) are a new class of ceramics with improved mechanical properties as compared to pure alumina. They are obtained by dispersion of powder within an alumina matrix. Of the three new ceramics studied here, A20Z possesses the best mechanical properties as well as tribological properties superior to those of pure alumina whether it is used in ceramic-ceramic or ceramic-polyethylene combination.Mechanical behaviour and tissue response afterin vivo implantation were studied. Small four-point flexion bars obtained by pressureless sintering were implanted subcutaneously in the rat. The mechanical properties were unmodified even after one year from implantation.The tissue response was studied up to one year on cylinders implanted in the paravertebral muscles of Wistar rats, and was evaluated by qualitative examination of the encapsulating membrane and measurement of its thickness in relation to pure alumina. The tissue responses were comparable for both alumina and the three tested ceramics.     

Vector characterization of photodetectors, photoreceivers, andoptical pulse sources by time-domain pulse response measurements

Deconvolution of measurement system effects from pulse response measurements is demonstrated to yield reproducible, accurate characterization of the impulse response (and vector frequency response) of a photodetector or photoreceiver, as well as the intensity waveform of an optical pulse. Calibration is based on a <3-ps FWHM (full width at half maximum) optical pulse and a 50-GHz 3-dB bandwidth electrical sampling system. Vector characterization of a photodetector/photoreceiver to >40 GHz and an optical pulse source to >30 GHz are demonstrated. Calibration and effects of noise are discussed     

Performance characteristics of a composite multivariate quality control system.

We present the results of an evaluation of the performance characteristics of a composite multivariate quality control (CMQC) system that incorporates quality control rules for univariate, multivariate, and correlation conditions. The CMQC system evaluated is designed to help analysts detect unacceptable trends and systematic error in one or more variables, unacceptable random error in one or more variables, and unacceptable changes in the correlation structure of any pair of variables. It is also designed to be tolerant of missing data, to allow analysts to reject as few as one or as many as all variables in a run, and to provide analysts with control statistics and graphics that logically relate to sources of analytical error. We show that the various components of the CMQC system have adequate statistical power to detect systematic errors, random errors, and correlation changes under the conditions likely to be encountered with multivariate analytical measurement systems: (1) a single variable with increased systematic or random error; (2) all variables or a subgroup of variables affected by a common problem that increases systematic or random error; and (3) missing data for one or more variables in a run. We also show that the power of the multivariate component of the CMQC system to detect systematic and random errors is higher than the power of an alternative multivariate test criterion.     

The use of probability theory in fracture mechanics—A case study

A probabilistic approach to fracture mechanics in the form of a typical case study is described wherein the integrity of a high-pressure water pipeline is assessed. An analysis methodology is discussed incorporating the probability density functions of defect sizes, the statistics of defect occurrences and the statistical distribution of material properties. This method enables the analyst to supply a very simple assessment of safety, based on the probability of failure (a single number) which may be compared to accepted industrial standards (e.g. 10⁻⁶ for nuclear applications). It is argued that this method often offers the only way to scientifically and economically assess the integrity of fracture prone structures.     

Pullout tests of epoxy-coated reinforcement in concrete

The bond strength and slip of epoxy-coated reinforcing bars in concrete have been evaluated by carrying out single pullout and double pullout tests. In extended single pullout tests, slip measurements were made while tensile force was applied to reinforcing bars embedded in concrete. In double pullout tests, 20 cycles of load were applied at levels of steel stress between zero and 0·5 times characteristic steel strength. Strains were measured by electrical resistance strain gauges glued inside the bars. Both epoxy-coated and uncoated bars were used in the investigation, to obtain comparative results. The strain gradient along the bar was found to be less for the coated reinforcement. In general, the epoxy coating was found to increase slip in bond and thereby reduce the bond performance of coated bars.