The East Kent Chalk Aquifer during the 1988-92 Drought

Groundwater resources of Chalk aquifers may become depleted during drought periods; major causes of this depletion include reductions in the aquifer transmissivity and the interaction between aquifers and rivers. In the East Kent aquifer there are certain catchments where difficulties are encountered in maintaining yields but, in other catchments, drought periods have little effect on the available resources. A mathematical model is developed to help understand the flow processes within the aquifer system, and the model is used to predict the consequences of possible abstraction scenarios.     

A NOVEL METHOD FOR BITTERNESS DETERMINATION IN BEER USING A DELAYED FLUORESCENCE TECHNIQUE

The established technique of time-resolved fluorescent spectroscopy has been applied to the rapid measurement of beer bitterness. This novel application utilises the unique long-lived fluorescence properties of the lanthanide, europium. Europium ions have the ability to selectively chelate β-tricarbonyl structures such as the iso-humulones. The resultant complex is measured by irradiating the sample at a specific wavelength and measuring the intensity of the long-lived emission. The bitterness method measures the total contribution of iso-alpha acids and related congeners. A linear relationship between standard iso-alpha acids solutions and emission intensity was found. However, in beer the effects of colour and other interfering compounds were significant. Decolourization of the beer did not improve the correlation with BU. This paper presents a preliminary investigation into the potential applications of this novel method.     

SITUATIONAL AND PERSONALITY CORRELATES OF PREDICTIVE ACCURACY.

INVESTIGATED THE RELATIONSHIPS BETWEEN PREDICTIVE ACCURACY AND TYPE OF INTERVIEWER-INTERVIEWEE CONTACT. 120 UNDERGRADUATES WERE ADMINISTERED THE ADJECTIVE CHECK LIST (ACL) AND ASSIGNED THE ROLES OF INTERVIEWER, INTERVIEWEE (OBJECT), AND O. AFTER A SHORT INTERVIEW, SEEN BY THE O THROUGH A 1-WAY MIRROR, THE INTERVIEWER AND O PREDICTED THE OBJECT'S RESPONSES TO THE ACL. FEMALES WERE PREDICTED MORE ACCURATELY THAN MALES REGARDLESS OF CONDITION OF CONTACT OR SEX OF JUDGE. THERE WAS NO DIFFERENCE IN ACCURACY OF PREDICTION BETWEEN DIRECT AND INDIRECT CONTACT WITH THE OBJECT. HIGH-ACCURACY JUDGES OBTAINED HIGHER SCORES ON THE ORDER SCALE OF THE ACL AND LOWER SCORES ON THE CHANGE AND AFFILIATION SCALES THAN LOW-ACCURACY JUDGES. UNDER CONDITIONS OF DIRECT CONTACT, HIGHER ACCURACY WAS ASSOCIATED WITH A HIGHER NEED FOR ACHIEVEMENT; UNDER THE CONDITION OF INDIRECT CONTACT, THIS PERSONALITY ATTRIBUTE WAS ASSOCIATED WITH LOWER ACCURACY. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Measurement of the redox potential of wine

A reproducible method for measuring the redox potential of wines using platinum electrodes was developed involving a consistent electrode pretreatment and carefully controlled experimental conditions. Reproducibility favoured platinized electrodes (±3mV), over unplatinized electrodes (±6mV), while poisoning was found to have a greater effect on platinized electrodes. However, the dependence of the potential upon the degree of platinization indicated that both platinized and unplatinized electrodes should be used to maximize the information obtained about the redox state of a wine. A linear relationship was observed between the potential and pHof 26 wines tested, particularly on platinized electrodes. The measured potentials are discussed in terms of mixed potential theory and the influence of adsorbates.     

ON THE CHOICE OF A DERIVATIVE BOUNDARY ELEMENT FORMULATION USING HERMITE INTERPOLATION

This paper reports on some problems that can arise with the use of regularized derivative boundary integral equations. It concentrates on developing a formulation for the simple Laplace equation using a cubic Hermite interpolation and shows how certain combinations of derivative and conventional boundary integral equations can result in a solution scheme severely lacking in stability. With some simple two- and three-dimensional geometries, the derivative equations on their own do not provide enough information to solve a Dirichlet problem. Even combinations of the conventional and derivative equations fail for some simple geometries. We conclude that the only consistently successful combination is that of the conventional equation with the tangential derivative equation, which showed cubic convergence of results with mesh refinement. Numerical results are presented for this scheme in both two and three dimensions.     

Heat Inactivation of Protease Inhibitors in a Soybean Line Lacking the Kunitz Trypsin Inhibitor

The effect of heat treatment (autoclaving at 121°C, 15 psi for various periods of time) on the trypsin- and chymotrypsin-inhibitor activities of a soybean line lacking the Kunitz trypsin inhibitor (SBTI) was compared to that of commercial untoasted soy flour. The trypsin- and chymotrypsin-inhibitor activites of the SBTI-free soybeans were approximately one-half and three-fourths that of the soy flour, respectively. Less heat treatment was required to produce a given level of destruction of these inhibitor activities in the case of the SBTI-free soybeans than with the soy flour. The effect of heat on the ratio of chymotrypsin- to trypsin-inhibitor activities was notably different between the two soybean samples and presumably reflects differences in the amounts and thermal stability of the various protease inhibitors known to be present in soybeans. The nutritional implications of these findings are discussed.     

Three-dimensional surface texture visualization of bone tissue through epifluorescence-based serial block face imaging

Serial block face imaging is a microscopy technique in which the top of a specimen is cut or ground away and a mosaic of images is collected of the newly revealed cross-section. Images collected from each slice are then digitally stacked to achieve 3D images. The development of fully automated image acquisition devices has made serial block face imaging more attractive by greatly reducing labour requirements. The technique is particularly attractive for studies of biological activity within cancellous bone as it has the capability of achieving direct, automated measures of biological and morphological traits and their associations with one another. When used with fluorescence microscopy, serial block face imaging has the potential to achieve 3D images of tissue as well as fluorescent markers of biological activity. Epifluorescence-based serial block face imaging presents a number of unique challenges for visualizing bone specimens due to noise generated by sub-surface signal and local variations in tissue autofluorescence. Here we present techniques for processing serial block face images of trabecular bone using a combination of non-uniform illumination correction, precise tiling of the mosaic in each cross-section, cross-section alignment for vertical stacking, removal of sub-surface signal and segmentation. The resulting techniques allow examination of bone surface texture that will enable 3D quantitative measures of biological processes in cancellous bone biopsies.     

Deposition and characterization of copper indium gallium diselenide films by laser ablation and flash evaporation for use in solar cells

Copper indium gallium diselenide (CIGS) thin films have shown considerable promise for use as an absorber layer in high-efficiency solar cells. The initial results obtained from the preparation of CIGS films via laser ablation and flash evaporation are presented along with a comparison of the two deposition processes. The as-deposited CIGS films have been characterized by a variety of techniques, namely Rutherford back scattering and energy dispersive analysis using X-rays for composition measurements X-ray diffraction and Raman spectroscopy for structure elucidation, SEM for surface examination, and the four-point probe for resistivity measurements. In essence, good-quality coatings of CIGS were produced from both deposition processes in terms of their stoichiometry, electrical and structural properties. This revised version was published online in November 2006 with corrections to the Cover Date.     

Measuring stress intensity factors during fatigue crack growth using thermoelasticity

Thermoelastic stress analysis has been developed in recent years as a direct method of investigating the crack tip stresses in a structure under cyclic loading. This is a consequence of the fact that stress intensity factors obtained from thermoelastic experiments are determined from the cyclic stress field ahead of a fatigue crack, rather than inferred from measurement of the crack length and load range. In the present paper the results of fatigue crack growth tests performed on welded ferritic steel plates are reported. From the results it can be observed that the technique is sensitive to the effects of crack closure and the presence of tensile and compressive residual stresses due to welding.