Improving particle size measurement using multi-flash imaging

An accurate calculation of the size distribution of coarse particles is crucial in the mining and quarrying industry. Machine vision has the capability to overcome many inherent limitations of traditional sieving methods and is an active research area. However, inaccurate image segmentation of particles through software based algorithms is a significant source of error. In this paper, a hardware based approach to improving image segmentation is demonstrated using multi-flash Imaging (MFI), where multiple images captured with different illumination allows depth edges around a particle to be captured through shadow information. The MFI method is compared with conventional segmentation methods such as watershed and Canny edge detection. In order to provide more accurate evaluation of performance wooden spheres of known diameter were evaluated. Imaging the size distribution of pebbles provided a practical scenario in the evaluation of MFI. The results revealed that MFI produced more accurate size estimations than conventional segmentation techniques for both the wooden spheres and pebbles, demonstrating the potential for future use in the mining industry.     

Active Micromachined Integrated Terahertz Circuits

Schottky barrier diodes have been integrated into on-chip rectangular waveguides. Two novel techniques have been developed to fabricate diodes with posts suitable for integration into waveguides. One technique produces diodes with anode diameters of the order of microns with post heights from 90 to 125 microns and the second technique produces sub-micron anodes with post heights around 20 microns. A method has been developed to incorporate these structures into a rectangular waveguide and provide a top contact onto the anode which could be used as an I.F. output in a mixer circuit. Devices have been fabricated and D.C. characterized.     

A pilot study of the efficacy of residuum lodges for managing sediment delivery to impoundment reservoirs

Residuum lodges comprise small dams constructed on feeder streams immediately before they enter a reservoir, behind which ponds form, where sediment is deposited. Despite their construction on many impoundment reservoirs (IRE) and catchwaters, little research has previously investigated their efficacy at removing sediments from feeder streams. The current pilot study has, therefore, been carried out at an IRE supplying Halifax, West Yorkshire, UK, where a residuum lodge was recently cleaned out. Sediment concentrations reaching the reservoir were reduced by up to 42% although no certain impacts were noted on the other water quality variables that were measured. Moreover, it was found that the clearance operation did not result in the release of excessive quantities of sediment into the reservoir. It was estimated that the cleared residuum lodge would take 12 years to refill. A survey of other residuum lodges in the Yorkshire region showed there to be considerable differences in their remaining capacities.     

Reliability and validity of Mississippi Scale for Combat-Related Posttraumatic Stress Disorder.

This study examined the reliability and validity of the Mississippi Scale for Combat-Related Posttraumatic Stress Disorder (M-PTSD) in a sample of Vietnam combat veterans with PTSD (n?=?101) and substance-abusing patients without combat-related PTSD (n?=?102). The M-PTSD was found to have high internal consistency, and a principle-components analysis indicated that its items measure three dimensions: intrusive reexperiencing/numbing-avoidance, anger/lability, and social alienation. Discriminant validity of the M-PTSD was supported by its high sensitivity in identifying PTSD patients (93%) and specificity in discriminating them from substance-abusing control subjects (88.2%). Finally, convergent validity of the M-PTSD was substantiated by significant correlations of the instrument with measures of combat exposure and interview and psychometric measures of PTSD symptomatology. The M-PTSD was shown to be a highly reliable and valid measure of the spectrum of PTSD symptoms in Vietnam combat veterans. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

High‐throughput microbial bioassays to screen potential New Zealand functional food ingredients intended to manage the growth of probiotic and pathogenic gut bacteria

A spectrophotometric bioassay was used to screen selected food ingredients intended for development of functional foods designed to influence the growth of gut bacteria. Dose–response profiles displaying Δ_growth, the magnitude of deviation from growth of controls, were generated for probiotics Lactobacillus reuteri, Lactobacillus rhamnosus, Bifidobacterium lactis and pathogens Escherichia coli, Salmonella Typhimurium and Staphylococcus aureus. Ingredients were manuka honey UMF?20+(dose‐dependently increased probiotics and decreased pathogens); bee pollen (biphasic growth effects against all); Rosehips and BroccoSprouts^® (increased all dose‐dependently); blackcurrant oil (little effect) and propolis (inhibited all strains). Ingredients were also bioassayed in pairs to assess desirable or undesirable synergistic interactions. Observed synergies included manuka honey (predominantly desirable); rosehips or BroccoSprouts® (desirable and undesirable); blackcurrant oil (desirable) and propolis (tended towards synergies reinforcing its antimicrobial effects), collectively revealing a complex web of interactions which varied by ingredient and bacterial strain. Manuka honey was particularly effective at influencing gut bacteria. The surprising frequency of undesirable synergistic interactions illustrates the importance of pre‐testing potential ingredient combinations intended for use in functional foods.     

A test of the extended intergroup contact hypothesis: The mediating role of intergroup anxiety, perceived ingroup and outgroup norms, and inclusion of the outgroup in the self.

S. C. Wright, A. Aron, T. McLaughlin-Volpe, and S. A. Ropp (1997) proposed that the benefits associated with cross-group friendship might also stem from vicarious experiences of friendship. Extended contact was proposed to reduce prejudice by reducing intergroup anxiety, by generating perceptions of positive ingroup and outgroup norms regarding the other group, and through inclusion of the outgroup in the self. This article documents the first test of Wright et al.'s model, which used structural equation modeling among two independent samples in the context of South Asian-White relations in the United Kingdom. Supporting the model, all four variables mediated the relationship between extended contact and outgroup attitude, controlling for the effect of direct contact. A number of alternative models were ruled out, indicating that the four mediators operate concurrently rather than predicting one another. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A quasi-experimental assessment of the effect of computerizing noncognitive paper-and-pencil measurements: A test of measurement equivalence.

Previous studies have provided evidence to question the equivalence of data gathered by different administration modes and to suggest that noncognitive instruments validated for paper-and-pencil administration may not be valid for computerized administration. In this study, a series of analyses of the variance–covariance matrices tested the measurement equivalence of data collected from paper-and-pencil and computerized formats. Four work-related noncognitive psychological measures were tested in this study. There was no evidence that administration mode had an effect on measurement equivalence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Output waveforms in the replay process in digital magneticrecording

The output voltage waveforms expected when replaying with various head structures from media magnetized in arbitrary directions are predicted. Expressions are given in useful closed forms for the outputs in isolated and pulse crowded circumstances. Output waveforms are shown for a range of orientations of the recorded magnetization to reveal aspects of pulse symmetry and their effects on “roll-off” curves     

AIDS Clinical Trials Group Study 094: a phase I/II trial of ABV chemotherapy with zidovudine and recombinant human GM-CSF in AIDS-related Kaposi''s sarcoma

The aim of this study was to evaluate psychosocial quality of life after heart transplantation. We examined 29 patients (25 M and 4 F), average age was 43.5 y (18-62 y). The age at time of heart transplantation was 43 years (17-55 y). The time after heart transplantation was 3.3 year (0.3-9 y). Spielberger's Questionnaire of Anxiety, Knobloch's inventory of neuroticism, Freiburg's Personality Inventory and Quality of Life Inventory were used, 33% of patients demonstrated increasing frequency and 29% of patients increasing intensity of neurotic symptoms. 23% of patients presented increasing levels of anxiety (as a state). The personality dimensions (depression, excitability and low emotional stability) displayed high frequency. The results showed that patients were more satisfied with family support, with sexual activities, and less satisfied with financial situation, social activities, social isolations, sleep, memory, excitability, fatigue. 41.5% of patients returned back to work. The results indicate that these psychosocial factors play an important role in quality of life after heart transplantation. That is why if is necessary to dedicate an increasing attention to them. (Tab. 1, Fig. 6, Ref. 14.)     

Failure of femoral head fixation: a cadaveric analysis of lag screw cut-out with the gamma locking nail and AO dynamic hip screw

The most commonly reported failure mode of sliding hip screws in published literature is cut-out of the lag screw. This study investigates the resistance to failure of the femoral head, with lag screws used in two types of sliding hip screws, the gamma locking nail (Howmedica) and the dynamic hip screw (DHS) (Synthes). The investigation consisted of biomechanical tests under static loading conditions on 12 pairs of cadaveric femoral heads, to establish the failure loads due to screw cut-out for the two implant lag screws. The gamma nail appeared to reduce the tendency to cut-out in the osteoporotic bone (soft) associated with elderly patients in whom these devices are commonly used (p < 0.05). In high density bone (hard) the gamma lag screw also appeared to be stronger, because the DHS showed a tendency to bend. The larger diameter of the gamma nail lag screw resists bending and appears to reduce the risk of cut-out compared with the DHS.