A dedicated tidal stream atlas of the stratified tidal flows near Stonecutters Bridge,Hong Kong,based on 3D numerical simulations with HLES

Construction works at the Stonecutters Bridge crossing the Rambler Channel in Hong Kong involve bridge deck lift operations with dynamically positioned barges. Nautical simulations for marine safety assessment and the programming of the bridge deck lift operations require reliable predictions of the local currents. To that purpose, we designed a detailed hydrodynamic Delft3D-FLOW model for simulating 3D stratified tidal flow and larger-scale eddy-dynamics using Horizontal Large Eddy Simulation (HLES). This model was nested in the 3D hydrodynamic model of the Pearl River estuary and the Hong Kong waters, which has been extensively calibrated and validated in other studies in the Hong Kong area. The results of the detailed model show good agreement with dedicated field measurements for both the dry and wet seasons. Based on tidal analysis of the model results, predictions for the water levels and currents could be made that include the complex flow patterns and (tidally driven) eddies and recirculations. For easy prediction of the flow conditions in the future, a digital tidal stream atlas (Delft-STREAM) was set up that is capable of predicting these flow fields. This tool provided a valuable contribution to the programming and execution of the marine works of Stonecutters Bridge. The new development in this study is the inclusion of complex 3D flow patterns into a digital tidal stream atlas, capable of predicting detailed flow fields for construction planning purposes.     

Characterization of cellulose aldehyde using Fourier transform infrared spectroscopy

Fourier transform infrared spectroscopy has been used to study cellulose aldehyde groups in bleached cotton, unbleached cotton, and in periodate oxidized cotton. Second derivative spectroscopy could reproducibly identify aldehyde bonds in oxidized cotton only if the samples were predried at 110°C for 24 h; the aldehyde band appeared at 1732–1734 cm^?1. Diffuse reflectance spectroscopy in the Environmental Chamber readily detected the above aldehyde absorbances at temperatures above 100°C. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1195–1202, 2001     

Decolourisation of Orange II by a Wood-Rotting Fungus

The decolourisation of Orange II by a wood-rotting fungus has been studied. It was found that Fungus F29 could effectively decolourise Orange II especially when grown as pelleted mycelia under agitated conditions. Many factors affecting the decolourisation process in nitrogen-limited media (NLM) were studied, including: concentration of glucose, NH₄⁺, Mn(II) and veratryl alcohol; initial pH; amount of mycelium; mycelial age; Orange II concentration; temperature. Results showed that the media containing Orange II at 1000 mg dm⁻³ (or higher) could be decolourised by 98% of the initial colour (A_{480 nm}) in 2 days, in most conditions tested, and that the mycelia could be repeatedly reused. © 1997 SCI.     

Orbit determination in the presence of unmodeled accelerations

In this investigation, the unmodeled accelerations acting on an orbiting space vehicle are approximated by a first-order Gauss-Markov process. An extended Kalman-Bucy filter is used to estimate the state and the unmodeled accelerations at each observation epoch. Applications of the estimation algorithm to tracking data obtained during the Apollo 10 and 11 missions indicate that a more accurate estimate of the state is obtained and that the estimated values of the unmodeled accelerations can be correlated with physical phenomena neglected by the mathematical model.     

An investigation of sex differences in spatial ability: Mental rotation of three-dimensional objects.

Presented 2-dimensional computer-generated representations of 3-dimensional objects in pairs to 20 male and 20 female right-handed undergraduates. Ss were given 15 sec to make a same-different judgment of the objects, one of which was rotated 0°, 40°, 80°, 120°, or 160° from the other. Ss were also assessed on 2 standard spatial ability tests (the Spatial Relations subtest of the Differential Aptitude Tests, Form L, and the Standardized Road-Map Test of Direction Sense) and a verbal-imagery questionnaire. Analyses of the data showed that men were more accurate than women, and that the slope of the function relating response time to degree of rotation was steeper in women. There was a significant linear relation between performance and the degree of rotation. Rate of rotation and accuracy correlated with the other tests of spatial ability. Response time slope correlated with imagery in men but not in women, suggesting that frequent use of visual imagery was related to mental rotation rate in men, but not in women. There were no clear relations between performance and the strategy Ss professed to use in doing the mental rotation. (French summary) (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An algorithm for propagating the square-root covariance matrix in triangular form

A method for propagating the square root of the state error covariance matrix in lower triangular form is described. The algorithm can be combined with any triangular square-root measurement update algorithm to obtain a triangular square-root sequential estimation algorithm. The triangular square-root algorithm compares favorably with the convential sequential estimation algorithm with regard to computation time.     

Adaptive sequential estimation with unknown noise statistics

Sequential estimators are derived for suboptimal adaptive estimation of the unknown a priori state and observation noise statistics simultaneously with the system state. First- and second-order moments of the noise processes are estimated based on state and observation noise samples generated in the Kalman filter algorithm. A limited memory algorithm is developed for adaptive correction of the a priori statistics which are intended to compensate for time-varying model errors. The algorithm provides improved state estimates at little computational expense when applied to an orbit determination problem for a near-earth satellite with significant modeling errors.     

Priority water research questions as determined by UK practitioners and policy makers

Several recent studies have emphasised the need for a more integrated process in which researchers, policy makers and practitioners interact to identify research priorities. This paper discusses such a process with respect to the UK water sector, detailing how questions were developed through inter-disciplinary collaboration using online questionnaires and a stakeholder workshop. The paper details the 94 key questions arising, and provides commentary on their scale and scope. Prioritisation voting divided the nine research themes into three categories: (1) extreme events (primarily flooding), valuing freshwater services, and water supply, treatment and distribution [each > 150/1109 votes]; (2) freshwater pollution and integrated catchment management [100-150 votes] and; (3) freshwater biodiversity, water industry governance, understanding and managing demand and communicating water research [50-100 votes]. The biggest demand was for research to improve understanding of intervention impacts in the water environment, while a need for improved understanding of basic processes was also clearly expressed, particularly with respect to impacts of pollution and aquatic ecosystems. Questions that addressed aspects of appraisal, particularly incorporation of ecological service values into decision making, were also strongly represented. The findings revealed that sustainability has entered the lexicon of the UK water sector, but much remains to be done to embed the concept operationally, with key sustainability issues such as resilience and interaction with related key sectors, such as energy and agriculture, relatively poorly addressed. However, the exercise also revealed that a necessary condition for sustainable development, effective communication between scientists, practitioners and policy makers, already appears to be relatively well established in the UK water sector.     

Resistance of A-431 epidermoid carcinoma cells to early membrane changes induced by tumour promoters

The A-431 human epidermoid carcinoma cell line was resistant to 12-O-tetradecanoylphorbol-13-acetate (TPA) inhibition of epidermal growth factor binding, enhanced incorporation of [3H]choline into phospholipids and uptake of 86Rb an [3H]2-deoxyglucose. The cells were also resistant to TPA-stimulated release of radioactive choline derivatives and arachidonic acid from cells prelabelled with [3H]choline or [14C]arachidonic acid, respectively. The A-431 cells did not metabolise [3H]TPA. Despite their TPA-unresponsiveness, A-431 cells contained specific, high affinity binding sites for [3H]phorbol-12,13-dibutyrate with characteristics similar to other cultured cell lines.