Characterising the wave power potential of the Scottish coastal environment

The study focuses around the energetic waters of Scotland that has expressed high interest in the development of wave energy farms. There are only a few long-term suitable studies characterising coastal locations. A detail coastal resource assessment is provided, focusing on wave energy and site characterisation. Mean nearshore energy content in the Western coasts is ≥50 kW/m and on the East ≈10 kW/m. Monthly and seasonal analyses outline available resource and annual variations. Availability of production is also examined, West coastlines present higher levels, however, depending on resource and wave converters operational range significant differences are shown. Availability levels on the East coastline are low ≈40% due to lower wave heights, while Western locations record consistently over 80% at both scenarios examined. Results discuss the potential applicability of favourable wave converters, and characteristics which achieve maximum utilisation based on the local environment

On the Variation of Turbulence in a High-Velocity Tidal Channel

This study presents the variation in turbulence parameters derived from site measurements at a tidal energy test site. Measurements were made towards the southern end of the European Marine Energy Centre’s tidal energy test site at the Fall of Warness (Orkney, Scotland). Four bottom mounted divergent-beam Acoustic Doppler Current Profilers (ADCPs) were deployed at three locations over an area of 2 km by 1.4 km to assess the spatial and temporal variation in turbulence in the southern entrance to the channel. During the measurement campaign, average flood velocities of 2 ms−1 were recorded with maximum flow speeds of 3 ms−1 in the absence of significant wave activity. The velocity fluctuations and turbulence parameters show the presence of large turbulent structures at each location. The easternmost profiler located in the wake of a nearby headland during ebb tide, recorded flow shielding effects that reduced velocities to almost zero and produced large turbulence intensities. The depth-dependent analysis of turbulence parameters reveals large velocity variations with complex profiles that do not follow the standard smooth shear profile. Furthermore, turbulence parameters based on data collected from ADCPs deployed in a multi-carrier frame at the same location and time period, show significant differences. This shows a large sensitivity to the make and model of ADCPs with regards to turbulence. Turbulence integral length scales were calculated, and show eddies exceeding 30 m in size. Direct comparison of the length scales derived from the streamwise velocity component and along-beam velocities show very similar magnitudes and distributions with tidal phase

A Study on Development of Pediatric Reference Charts

RATIONALE: Pediatric growth pattern differences continue even after controlling for various factors such as nutrition, income distribution, environment, maternal/child health care and availability of health care infrastructures. Therefore it is recommended that every country should use reference height and weight curves based on measurements on their own children. AIM OF THE STUDY: To construct pediatric reference centile charts for weight, height and body mass index using maximum penalized likelihood LMS method for boys and girls separately from ages 6 -12 years. STUDY OBJECTIVES: The Primary outcome measures were; 1. Construction of percentile charts using LMS method, 2. Calculation of Z- score using LMS method. Secondary outcome measures were; 1. Making Weight-for- age centile chart for boys and girls separately. 2. Making Height-for-age centile chart for boys and girls separately. 3. Making weight-for-height centile chart for boys and girls separately. 4. Making Body Mass Index centile chart for boys and girls separately. 5. Calculation of WAZ, WHZ ,HAZ and BMI Z score for boys and girls separately. 6. Comparison of American National Center for Health Statistics/ Center for Disease Control (NCHS/CDC2000/WHO2007) references with locally weighted. 7. Estimation of prevalence of malnutrition, overweight and obesity among Tamil Nadu children. STUDY DESIGN: Population based cross-sectional multi-site (various schools) study design. SETTING: The study was conducted at the Institute of Child Health and Hospital for children, Egmore, Chennai-8. STUDY POPULATION: The study population consisted of 6-12 years children from all social groups and from families of high, moderate and low income. TARGET POPULATION: The target population consisted of 6-12 years children in the selected urban–rural middle schools based on a representative sample of 2520 boys and 2520 girls. SAMPLE SIZE: Sample size was estimated using previous studies prevalence of normal children in the population 48%, with 5% relative precision and 95% of confidence. The calculated sample size was 1665.This was multiplied by 3 (bringing the sample size up to 4995) to allow for design effect due to application of cluster sampling method. For equal distribution of sample in clusters the ultimate sample size required for the study was determined to 5040 children. Tools used: Part I: Socio-demographic data tool, Part II: Anthropometric measurement tool. Outcome variables: 1. Percentile charts. 2. Z- score. 3. Comparison with NCHS/WHO2007/CDC2000 charts. 4. Prevalence of wasted ,stunted, underweight, overweight, obesity. METHODOLOGY: A total of 5040 apparently healthy boys and girls aged 6 to 12 years were recruited using population based cross-sectional multi-site (various schools) study design. Anthropometric measurements were collected as per WHO standards. To construct smoothened percentile reference charts, the lamda-mu-sigma-additional parameter (LMSP) method using Box-Cox power exponential (BCPE) distribution model was adopted. LMSP summarizes the changing distribution with age according to 4 curves representing the median (M), the coefficient of variation (S), skewness (L), and kurtosis (P). BCPE distribution takes the idea of having a range of power transformations (rather than the traditional square root, log, and inverse) available to improve the efficacy of normalizing and variance equalizing for both positively and negatively skewed, and for both leptokurtic-platykurtic variables. Maximum penalized likelihood, the Generalized Additive Models were used. The centile curves of height, weight and BMI were fitted by BCPE (μ, _, _, _ ) models, and the parameters, μ, _, _ and _, were smoothened by cubic smoothing splines. The goodness-of-fit of BCPE models were assessed by worm plot and Q-test. The degrees of freedom, with respect to the parameter curves of μ, _, _ and _ from BCPE distribution, were selected according as the smallest AIC and GAIC(3), and the centile curves were fitted by BCPE distribution. RESULTS: Comparing present study charts with those of NCHS/WHO2007/CDC2000 chart showed significant differences between growth patterns of our children and other populations. Estimated median 50th percentile shows Tamil Nadu children anthropometric measurements are lower than NCHS/WHO2007/CDC2000 standard children. The study revealed that total prevalence of overweight was 10.6% (9.8%- 11.5%) and obesity was 3.0% (2.6%- 3.5%) when considering Body Mass Index of children between 6-12 years. Boys are having more overweight and obese than girls based on CDC2000 reference distributions of Z-scores for BMI. Present study shows prevalence of underweight is 31.7%, stunting is 19.7% and wasting is 24% among 6-12 years children. The boys had a risk of 1.23 (95%CI: 1.09-1.39) times greater to be underweight, 1.05 (95%CI: 0.92- 1.20) times greater to be stunting, and 1.03 (95%CI: 0.88- 1.20) times greater to be wasting than the girls. CONCLUSION: Since there is a secular trend in upward increase both in height and weight, a comparison of growth curves requires both methodological and secular similarity to determine similarity or difference. Local references would then provide a useful tool for health planning and screening inter-population differences. The results of the current study demonstrate the possibility of preparation of local growth charts and their importance in evaluating children's growth. Also their differences, relative to those prepared by global references, reflect the necessity of preparing local charts in future studies using longitudinal data