VALIDITY OF THE POWERLINE BOAT INSTRUMENTATION SYSTEM

The PowerLine Boat Instrumentation System3 is comprised of instrumented oarlocks capable of measuring pin forces in the direction of boat travel and oarlock angles. The aim of this study was to determine the reliability and validity of the force and angle data from the PowerLine Boat Instrumentation System in a laboratory setting. Data were collected with the sculling oarlocks affixed to a horizontally aligned, stabilised wing rigger. For force analysis, signals were collected at 50 Hz from both the PowerLine system and a 1 kN load cell4 during 10 repetitions at a rate of approximately 30 repetitions per minute. For angular analysis, whilst recording with PowerLine, oarlocks were repositioned for a minimum of two seconds at known angles in a random order using an inclinometer accurate to one tenth of a degree over a range of -80° to +60°, in 20° increments. Linear regression analysis through the origin was used to compare the PowerLine values with known values from the load cell and the inclinometer. Laboratory testing proved the force and angle sensors to be valid throughout the testing range (0 N to 554.8 + 20.4 N, and -80° to +60° respectively) when fully functioning. The PowerLine Boat Instrumentation System appears to be appropriate for measuring biomechanical variables in an elite sculling programme. On-water reliability testing is still required to fully evaluate their application in quantifying the effect of interventions made to technique or boat set-up

SUBSURFACE FLOW CONSTRUCTED WETLAND SYSTEM VEGETATED WITH PHRAGMITES KARKA IN THE TREATMENT OF DYE-RICH WASTEWATER

Some major parts of tropical Africa, especially in West Africa are nowadays grappling with the problem of degradation of the quality of fresh water by the introduction of effluents containing dyes from textile industries. In this study a low cost and economical method of treating dye-rich effluent using locally available macrophyte was investigated. The pilot Constructed Wetland (CW) consists of 1200 × 1000 × 1000 mm plastic tanks, filled with 500 mm deep 10-15 mm size granite overlaid with 150 mm thick sand (Cu = 1.15 and Cc = 6.8) substrate. The substrates had an hydraulic conductivity of 0.002 m/s. The pilot CW was planted with Phragmites Karka Retz. at 200 mm c/c to provide a high density bed. Irrigation was done intermittently at 6 days retention period with 0.05 m3 indigo dye rich wastewater from the local tie and dye textile industries and plant growth monitored. Physico-chemical parameters, Cr, Pb, Cu, Zn and Fe removal were also evaluated. The study revealed a 24 % growth rate reduction in the plants irrigated with indigo dye-rich wastewater. Reduction of TDS (50 %), TSS (66 %), EC (46 %) were also observed and the heavy metals evaluated showed an uptake of 64 %, 68 %, 78 %, 58 %, and 68 % for Cr, Pb, Zn, Cu, and Fe respectively by the CW. Phragmites karka as a macrophyte in Constructed Wetland was found to be efficient in dye-rich wastewater treatment.     &nbsp

Sizing and Layout Design of an Aeroelastic Wingbox Through Nested Optimization

The goals of this work are to 1) develop an optimization algorithm that can simultaneously handle a large number of sizing variables and topological layout variables for an aeroelastic wingbox optimization problem and 2) utilize this algorithm to ascertain the benefits of curvilinear wingbox components. The algorithm used here is a nested optimization, where the outer level optimizes the rib and skin stiffener layouts with a surrogate-based optimizer, and the inner level sizes all of the components via gradient-based optimization. Two optimizations are performed: one restricted to straight rib and stiffener components only, the other allowing curved members. A moderate 1.18% structural mass reduction is obtained through the use of curvilinear members

Large predatory coral trout species unlikely to meet increasing energetic demands in a warming ocean

Increased ocean temperature due to climate change is raising metabolic demands and energy requirements of marine ectotherms. If productivity of marine systems and fisheries are to persist, individual species must compensate for this demand through increasing energy acquisition or decreasing energy expenditure. Here we reveal that the most important coral reef fishery species in the Indo-west Pacific, the large predatory coral trout Plectropomus leopardus (Serranidae), can behaviourally adjust food intake to maintain body-condition under elevated temperatures, and acclimate over time to consume larger meals. However, these increased energetic demands are unlikely to be met by adequate production at lower trophic levels, as smaller prey species are often the first to decline in response to climate-induced loss of live coral and structural complexity. Consequently, ubiquitous increases in energy consumption due to climate change will increase top-down competition for a dwindling biomass of prey, potentially distorting entire food webs and associated fisheries

Crime and Psychiatric Disorders Among Youth in the US population: An Analysis of the National Comorbidity Survey-Adolescent Supplement

Objective Current knowledge regarding psychiatric disorders and crime in youth is limited to juvenile justice and community samples. This study examined relationships between psychiatric disorders and self-reported crime involvement in a sample of youth representative of the US population. Method The National Comorbidity Survey–Adolescent Supplement (N = 10,123; ages 13–17 years; 2001–2004) was used to examine the relationship between lifetime DSM-IV–based diagnoses, reported crime (property, violent, other), and arrest history. Logistic regression compared the odds of reported crime involvement with specific psychiatric disorders to those without any diagnoses, and examined the odds of crime by psychiatric comorbidity. Results Prevalence of crime was 18.4%. Youth with lifetime psychiatric disorders, compared to no disorders, had significantly greater odds of crime, including violent crime. For violent crime resulting in arrest, conduct disorder (CD) (odds ratio OR = 57.5; 95% CI = 30.4, 108.8), alcohol use disorders (OR = 19.5; 95% CI = 8.8, 43.2), and drug use disorders (OR = 16.1; 95% CI = 9.3, 27.7) had the greatest odds with similar findings for violent crime with no arrest. Psychiatric comorbidity increased the odds of crime. Youth with 3 or more diagnoses (16.0% of population) accounted for 54.1% of those reporting arrest for violent crime. Youth with at least 1 diagnosis committed 85.8% of crime, which was reduced to 67.9% by removing individuals with CD. Importantly, 88.2% of youth with mental illness reported never having committed any crime. Conclusion Our findings highlight the importance of improving access to mental health services for youthful offenders in community settings, given the substantial associations found between mental illness and crime in this nationally representative epidemiological sample

Assessing performance of modern Brillouin spectrometers

Brillouin spectroscopy and imaging has experienced a renaissance in recent years seeing vast improvements in methodology and increasing number of applications. With this resurgence has come the development of new spontaneous Brillouin instruments that often tout superior performance compared to established conventional systems such as tandem Fabry-Perot interferometers (TFPI). The performance of these new systems cannot always be thoroughly examined beyond the scope of the intended application, as applications often take precedence in reports. We therefore present evaluation of three modern Brillouin spectrometers: two VIPA-based spectrometers with wavelength-specific notch filters, and one scanning 6-pass TFPI. Performance analysis is presented along with a discussion about the dependence of measurements on excitation laser source and the various susceptibilities of each system

Neutralino dark matter vs galaxy formation

Neutralino dark matter may be incompatible with current cold dark matter models with cuspy dark halos, because excessive synchrotron radiation may originate from neutralino annihilations close to the black hole at the galactic center.Comment: 6 pages, 3 figures, talk given at "Sources and detection of dark matter in the Universe", Marina del Rey, CA, February 23-25, 200

IMPLEMENTATION OF THE ROOT BISECTION COMPUTATIONAL PHYSICS METHOD FOR THE DETERMINATION OF ROOTS OF NON-LINEAR EQUATIONS USING JAVA

Advancement in programming and language development has made possible improved efficiency and accuracy in solving numerical problems and hence the numerical computation of physical problems as used in Computational Physics. Hitherto, languages such as Basic, Fortran, C, among others, have commonly been employed in solving numerical problems. In this work, Java, a modern object oriented language was deployed in solving some physical problems, specifically, determination of roots of non-linear equations using the Root-Bisection Method. A comparison between results obtained showed faster convergence and greater accuracy using Java than as obtained using Fortran.     &nbsp

GEOELECTRIC PARAMETERS AND ELEMENTAL COMPOSITIONS OF THE TOP SOIL OF CAMP AREA, ABEOKUTA, SOUTH WESTERN NIGERIA

Vertical Electrical Sounding (VES) and elemental composition surveys were carried out at twenty-two (22) sites atª¤? Camp Area, Alabata Road, Abeokuta, Southwestern Nigeria. This was with a view to determining depth to water«¤??bearing zones and extent of soil contamination thereby saving residents not just the pain of recurrent losses incurred for investing in dry wells, but also not to invest in contaminated waters. The study area is underlain by associated rock suites which includes pegmatite and quartz veins. Field data obtained was modeled and interpreted to obtain the geophysical parameters of the area and delineate the groundwater potential zones. Soil samples were also collected at the 22 VES points, at depths of 10 cm and 100 cm; the Global Positioning Satellite (GPS) equipment was used to obtain the geographical position of each sample point. Determination of the elemental composition of soil samples collected at the 10 cm and 100 cm depths was made using Atomic Absorption Spectrophotometer. Two heavy metals (Pb, and Cr), five major elements (K, Ca, N, P and Mg) and five trace elements (Zn, Mn, Cu, Al and Fe) were detected. It was observed that the values, representing the amount of the heavy metals, the major elements, and the trace elements were far less, mostly insignificant, at the 100 cm depth representing about the interface between the first and second layers in majority of the VES stations sampled, than at the 10 cm depth, representing the topsoil of the first layer. The implication of this is that the elements are not strictly domiciled within the area studied but may be due to runoffs as the area slopes down. Moreover, going by the values at the 100 cm depth, the elements may not be capable of percolating into the underground water zones in the area of study, and thus might not have contaminated the underground water. Thus, at the current level, the underground water can be adjudged safe for human consumption.ª¤