Use of geographical information systems as a tool for predicting fish yield in tropical reservoirs : case study on Sri Lankan reservoirs

Use of geographical information systems (GIS) in inland fisheries has hitherto been essentially restricted to site evaluation for aquaculture development and assessment of limnological changes in time and space in individual water bodies. The present GIS study was conducted on the land-use pattern of the catchments of nine reservoirs in Sri Lanka, for which detailed fishery data, viz. yield, fishing intensity, landing size of major constituent species, together with selected limnological data such as conductivity and chlorophyll-a, were available. Potential statistical relationships (linear, curvilinear, exponential and second-order polynomial) of fish yield (FY, in kg ha−1 yr−1) to different land-use patterns, such as forest cover (FC, in km2) and shrub-land (SL, in km2), either singly, or in combination, and/or the ratio of each land type to reservoir area (RA in km2) and reservoir capacity (RC in km3), were explored. Highly significant relationships were evident between FY to the ratio of SL and/or FC+SL to RA and/or RC. Similarly, the above land-use types to RA and RC ratios were significantly related to limnological features of the reservoirs. The relationships of FY to various parameters obtained in this study were much better correlated than those relationships of FY to limnological and biological parameters used in yield prediction in tropical and temperate lacustrine waters previously.

Evaluation of the usefulness of 'Marvin'; a computerized assessment tool for investigative interviewers of children

This study examined the usefulness of a computerized developmental assessment tool, designed to provide investigative interviewers with knowledge about children's understanding of spatial, temporal, numerical, and color terms that may be relevant to the forensic setting. Specifically, the effect of the computer program (compared to a standard verbal and no assessment) was examined on 4- to 5-year-old children's recall of an independent event and their enjoyment of the interview process. In addition, children's performance on the computerized and verbal developmental assessment was compared with their performance when recalling the independent event. Overall, the children rated the assessment conducted on computer more favorably than the verbal assessment. Further, the verbal assessment elicited responses that were more consistent with their responses about the event than the computerized assessment. However, there was no difference in the accuracy and detail of children's responses about the independent event, irrespective of whether the children received the computerized or verbal assessment, or no assessment. Directions for future research are discussed.

Cutting angle method - a tool for constrained global optimization

Cutting angle method (CAM) is a deterministic global optimization technique applicable to Lipschitz functions f: Rn → R. The method builds a sequence of piecewise linear lower approximations to the objective function f. The sequence of solutions to these relaxed problems converges to the global minimum of f. This article adapts CAM to the case of linear constraints on the feasible domain. We show how the relaxed problems are modified, and how the numerical efficiency of solving these problems can be preserved. A number of numerical experiments confirms the improved numerical efficiency.

Cr(N,C) diffusion coating formation on pre-nitrocarburised H13 tool steel

The microstructural processes of Cr(N,C) coating formation by thermoreactive deposition and diffusion (TRD) on pre-nitrocarburised H13 tool steel were studied. Both nitrocarburising and TRD were performed in fluidized bed furnaces at 570 °C. During TRD, chromium was transferred from chromium powder in the fluidized bed, to the nitrocarburised substrates by gas-phase reactions initiated by reaction of HCl gas with the chromium. Addition of 30% H2 to the input inert gas was found to increase the rate of coating formation, although hydrogen reduction resulted in rapid loss of nitrogen to the surface. The reason for the increased rate of coating formation could not be established without further investigation, although several possible explanations have been proposed. It was found that porosity and the formation of an iron nitride ‘cover layer’ during nitrocarburising were the biggest influences on the microstructure of the Cr(N,C) coating. Microstructural characterization of the coatings was performed by scanning electron microscopy (SEM), X-ray diffraction (XRD) and glow discharge optical emission spectroscopy (GDOES).

Friction changes during compression tests using tool rotation technique

A compression test with rotating dies was employed to estimate the friction factor between aluminum samples and steel tooling during large plastic deformations. A cylindrical workpiece was compressed under dry and cold conditions. The magnitudes of torque and normal force were measured and
the average friction factor was calculated using the Coulomb friction law. It was found that under certain conditions the friction increased with increasing angular velocity of the die. This finding led to the conclusion that the choice of die rotation speed is important in interpreting the results from the twist compression test.

Application of bending under tension test to determine the effect of tool radius and the contact pressure on the coefficient of friction in sheet metal forming

To quantify the frictional behaviour in sheet forming operations, several laboratory experiments which simulate the real forming conditions are performed. The Bending Under Tension Test is one such experiment which is often used to represent the frictional flow of sheet material around a die or a punch radius. Different mathematical representations are used to determine the coefficient of friction in the Bending Under Tension Test. In general the change in the strip thickness in passing over the die radius is neglected and the radius of curvature to thickness ratio is assumed to be constant in these equations. However, the effect of roller radius, sheet thickness and the surface pressure are also omitted in some of these equations. This work quantitatively determined the effect of roller radius and the tooling pressure on the coefficient of friction. The Bending Under Tension Test was performed using rollers with different radii and also lubricants with different properties. The tool radii were found to have a direct influence in the contact pressure. The effect of roller radius on friction was considerable and it was observed that there is a clear relationship between the contact pressure and the coefficient of friction.

Pin on disc wear investigation of nitrocarburised H13 tool steel

Nitrocarburised H13 disks were tested in dry, sliding wear against a stationary ruby ball (pin). Three different 4 h nitrocarburising treatments were compared, using N2/NH3/CO2, N2/NH3/natural gas and N2/NH3 gas mixtures, resulting in compound layers of varying thickness, hardness, porosity and oxide morphology. During mild, oxidative wear, with the formation of abrasive wear debris, the most brittle and oxidised surfaces performed poorly. Polishing to a bright, reflective finish greatly reduced wear. However, the N2/NH3/CO2 sample also frequently maintained a 'very mild' wear regime, owing to the formation of a protective film between the wear surfaces, and resulting in a lowering of the friction coefficient. This treated surface was porous and covered in a complex layer of coarse oxide+epsi-carbonitride. Nitrocarburised samples and wear tracks were characterised by optical microscopy, SEM, atomic force microscopy and stylus profilometry.

Ferritic nitrocarburising of tool steels

Four different tool steel materials, P20, H13, M2 and D2, were nitrocarburised at 570°C in a fluidised bed furnace. The reactive diffusion of nitrogen and carbon into the various substrate microstructures is compared and related to the different alloy carbide distributions. The effect of carbon bearing gas (carbon dioxide, natural gas) on carbon absorption is reported, as well as its influence on compound layer growth and porosity. Partial reduction of Fe3O4 at the surface resulted in the formation of a complex, epsi-nitride containing oxide layer. In H13, carbon was deeply absorbed throughout the entire diffusion zone, affecting the growth of grain boundary cementite, nitrogen diffusivity and the sharpness of the compound layer: diffusion zone interface. When natural gas was used, carbon became highly concentrated in the compound layer, while surface decarburisation occurred with carbon dioxide. These microstructural effects are discussed in relation to hardness profiles, and compound layer hardness and ductility. The surfaces were characterised using glow discharge optical emission spectroscopy, optical and scanning electron microscopy and X-ray diffraction.

Mobile Architecture and Built Environment Laboratory (MABEL) - a building performance evaluation tool

This paper describes the Mobile Architecture and Built Environment Laboratory (MABEL) and its application for systematic building performance evaluation for compliance testing, commissioning, strategic and operational facility management and continuous improvement in the built environment.

The first part of the paper introduces the application areas of on-site building performance evaluation and discusses the shortcomings in this regard in current practice. It emphasises the need for on-site investigations to generate information on 'as built performance' for the 'feedback' loop between design, operation and occupancy of new buildings, retrofit or adjustment.

The second part introduces the Energy-Comfort-Behaviour Framework for 'across-the-board' building evaluation and discusses MABEL's role in this scheme. MABEL's objectives, procedures and the performance measurement matrix are explained and discussed.

Calibration and reliability of a school food checklist: a new tool for assessing school food and beverage consumption

There is a pressing need in Australia and other countries to develop systems for monitoring secular trends in childhood obesity and related behavioural and environmental determinants. Energy from foods and beverages consumed at school is an accessible indicator of children’s eating patterns and we have developed a school food checklist (SFC) to measure this. The SFC records the number of serves and source (home, canteen, vending machine) of 20 food and beverage categories. This study aims to assess the accuracy and to calibrate the SFC by comparing it to a weighed record (WR) and to evaluate inter-recorder reliability. Participants were 910 primary school children aged 5 to 12 years from a rural township in Victoria, Australia. WR were collected from a nonrandom sub-sample of 106 and a second sub-sample (n=46) had intake measured twice using the SFC to assess inter-recorder reliability. Mean energy values were 2992 kJ ± 924 and 3008 kJ ± 952 for the SFC and WR respectively and the correlation coefficient was strong (Pearson r = 0.77). The mean difference between the WR and SFC methods was 15 kJ (95% CI, -107 kJ to 138 kJ) and the limits of agreement (+2 standard deviations) were ± 1270 kJ. The SFC overestimated the energy/serve of breads and fruit drinks and under-estimated energy/serve from fat spreads, biscuits/crackers, muesli/fruit bars and fruit. Inter-recorder reliability was good (kappa 0.51). The SFC was designed to measure energy from food and beverages in schools. It has good accuracy and reliability and the revised version should further improve accuracy of the instrument.

High reproducibility of patellar tendon vascularity assessed by colour doppler ultrasonography : a reliable measurement tool for quantifying tendon pathology

Background: This study examined whether patellar tendon vascularity could be quantified accurately in the clinical setting using colour Doppler ultrasonography.

Methods: A sonographer and two radiologists visually estimated tendon vascularity in millimetres in 74 tendons during ultrasound (US) examination and from hard copy films. These estimates were then compared to the length of vessels measured from the digital image in millimetres and the correlation between them was determined. A subset of 16 tendons was used to compare the estimates of vascularity by two examiners at US examination.

Results: The estimation of vascular length at US examination correlated highly with the measured vascular length (r = 0.92; 95% confidence interval (CI) 0.87 to 0.94), as did the length estimated from the films (r = 0.94; 95% CI 0.9 to 0.96). The correlation between examiners was 0.84 (95% CI 0.51 to 0.94) for the estimates made during US examination and 0.85 (95% CI 0.59 to 0.95) for the vessel lengths measured from the digital images.

Conclusions: These excellent correlations indicate that tendon vascularity can be reliably estimated using colour Doppler ultrasonography and tendon vascularity could therefore be used by clinicians to rate clinical change. This method of quantifying tendon vascularity could also be used in research to investigate the effects of tendon treatments on vascularity.

Deception: a tool and curse for security management

With the proliferation of electronic information systems over the last two decades, the integrity of the stored data and its uses have become an essential component of effective organisational functioning. This digitised format, used in input, output, processing, storage, and communication, has given those wishing to deceive new opportunities. This paper examines the nature of deception and its potential as a new security risk in the information age.